fs/ext4/extents.c

   1 /*
   2  * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
   3  * Written by Alex Tomas <alex@clusterfs.com>
   4  *
   5  * Architecture independence:
   6  *   Copyright (c) 2005, Bull S.A.
   7  *   Written by Pierre Peiffer <pierre.peiffer@bull.net>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public Licens
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  21  */
  22
  23 /*
  24  * Extents support for EXT4
  25  *
  26  * TODO:
  27  *   - ext4*_error() should be used in some situations
  28  *   - analyze all BUG()/BUG_ON(), use -EIO where appropriate
  29  *   - smart tree reduction
  30  */
  31
  32 #include <linux/fs.h>
  33 #include <linux/time.h>
  34 #include <linux/jbd2.h>
  35 #include <linux/highuid.h>
  36 #include <linux/pagemap.h>
  37 #include <linux/quotaops.h>
  38 #include <linux/string.h>
  39 #include <linux/slab.h>
  40 #include <linux/falloc.h>
  41 #include <asm/uaccess.h>
  42 #include <linux/fiemap.h>
  43 #include "ext4_jbd2.h"
  44 #include "ext4_extents.h"
  45 #include "xattr.h"
  46
  47 #include <trace/events/ext4.h>
  48
  49 /*
  50  * used by extent splitting.
  51  */
  52 #define EXT4_EXT_MAY_ZEROOUT    0x1  /* safe to zeroout if split fails \
  53                                         due to ENOSPC */
  54 #define EXT4_EXT_MARK_UNINIT1   0x2  /* mark first half uninitialized */
  55 #define EXT4_EXT_MARK_UNINIT2   0x4  /* mark second half uninitialized */
  56
  57 #define EXT4_EXT_DATA_VALID1    0x8  /* first half contains valid data */
  58 #define EXT4_EXT_DATA_VALID2    0x10 /* second half contains valid data */
  59
  60 static __le32 ext4_extent_block_csum(struct inode *inode,
  61                                      struct ext4_extent_header *eh)
  62 {
  63         struct ext4_inode_info *ei = EXT4_I(inode);
  64         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
  65         __u32 csum;
  66
  67         csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
  68                            EXT4_EXTENT_TAIL_OFFSET(eh));
  69         return cpu_to_le32(csum);
  70 }
  71
  72 static int ext4_extent_block_csum_verify(struct inode *inode,
  73                                          struct ext4_extent_header *eh)
  74 {
  75         struct ext4_extent_tail *et;
  76
  77         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
  78                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
  79                 return 1;
  80
  81         et = find_ext4_extent_tail(eh);
  82         if (et->et_checksum != ext4_extent_block_csum(inode, eh))
  83                 return 0;
  84         return 1;
  85 }
  86
  87 static void ext4_extent_block_csum_set(struct inode *inode,
  88                                        struct ext4_extent_header *eh)
  89 {
  90         struct ext4_extent_tail *et;
  91
  92         if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
  93                 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
  94                 return;
  95
  96         et = find_ext4_extent_tail(eh);
  97         et->et_checksum = ext4_extent_block_csum(inode, eh);
  98 }
  99
 100 static int ext4_split_extent(handle_t *handle,
 101                                 struct inode *inode,
 102                                 struct ext4_ext_path *path,
 103                                 struct ext4_map_blocks *map,
 104                                 int split_flag,
 105                                 int flags);
 106
 107 static int ext4_split_extent_at(handle_t *handle,
 108                              struct inode *inode,
 109                              struct ext4_ext_path *path,
 110                              ext4_lblk_t split,
 111                              int split_flag,
 112                              int flags);
 113
 114 static int ext4_find_delayed_extent(struct inode *inode,
 115                                     struct extent_status *newes);
 116
 117 static int ext4_ext_truncate_extend_restart(handle_t *handle,
 118                                             struct inode *inode,
 119                                             int needed)
 120 {
 121         int err;
 122
 123         if (!ext4_handle_valid(handle))
 124                 return 0;
 125         if (handle->h_buffer_credits > needed)
 126                 return 0;
 127         err = ext4_journal_extend(handle, needed);
 128         if (err <= 0)
 129                 return err;
 130         err = ext4_truncate_restart_trans(handle, inode, needed);
 131         if (err == 0)
 132                 err = -EAGAIN;
 133
 134         return err;
 135 }
 136
 137 /*
 138  * could return:
 139  *  - EROFS
 140  *  - ENOMEM
 141  */
 142 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
 143                                 struct ext4_ext_path *path)
 144 {
 145         if (path->p_bh) {
 146                 /* path points to block */
 147                 return ext4_journal_get_write_access(handle, path->p_bh);
 148         }
 149         /* path points to leaf/index in inode body */
 150         /* we use in-core data, no need to protect them */
 151         return 0;
 152 }
 153
 154 /*
 155  * could return:
 156  *  - EROFS
 157  *  - ENOMEM
 158  *  - EIO
 159  */
 160 int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
 161                      struct inode *inode, struct ext4_ext_path *path)
 162 {
 163         int err;
 164         if (path->p_bh) {
 165                 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
 166                 /* path points to block */
 167                 err = __ext4_handle_dirty_metadata(where, line, handle,
 168                                                    inode, path->p_bh);
 169         } else {
 170                 /* path points to leaf/index in inode body */
 171                 err = ext4_mark_inode_dirty(handle, inode);
 172         }
 173         return err;
 174 }
 175
 176 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
 177                               struct ext4_ext_path *path,
 178                               ext4_lblk_t block)
 179 {
 180         if (path) {
 181                 int depth = path->p_depth;
 182                 struct ext4_extent *ex;
 183
 184                 /*
 185                  * Try to predict block placement assuming that we are
 186                  * filling in a file which will eventually be
 187                  * non-sparse --- i.e., in the case of libbfd writing
 188                  * an ELF object sections out-of-order but in a way
 189                  * the eventually results in a contiguous object or
 190                  * executable file, or some database extending a table
 191                  * space file.  However, this is actually somewhat
 192                  * non-ideal if we are writing a sparse file such as
 193                  * qemu or KVM writing a raw image file that is going
 194                  * to stay fairly sparse, since it will end up
 195                  * fragmenting the file system's free space.  Maybe we
 196                  * should have some hueristics or some way to allow
 197                  * userspace to pass a hint to file system,
 198                  * especially if the latter case turns out to be
 199                  * common.
 200                  */
 201                 ex = path[depth].p_ext;
 202                 if (ex) {
 203                         ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
 204                         ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
 205
 206                         if (block > ext_block)
 207                                 return ext_pblk + (block - ext_block);
 208                         else
 209                                 return ext_pblk - (ext_block - block);
 210                 }
 211
 212                 /* it looks like index is empty;
 213                  * try to find starting block from index itself */
 214                 if (path[depth].p_bh)
 215                         return path[depth].p_bh->b_blocknr;
 216         }
 217
 218         /* OK. use inode's group */
 219         return ext4_inode_to_goal_block(inode);
 220 }
 221
 222 /*
 223  * Allocation for a meta data block
 224  */
 225 static ext4_fsblk_t
 226 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
 227                         struct ext4_ext_path *path,
 228                         struct ext4_extent *ex, int *err, unsigned int flags)
 229 {
 230         ext4_fsblk_t goal, newblock;
 231
 232         goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
 233         newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
 234                                         NULL, err);
 235         return newblock;
 236 }
 237
 238 static inline int ext4_ext_space_block(struct inode *inode, int check)
 239 {
 240         int size;
 241
 242         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 243                         / sizeof(struct ext4_extent);
 244 #ifdef AGGRESSIVE_TEST
 245         if (!check && size > 6)
 246                 size = 6;
 247 #endif
 248         return size;
 249 }
 250
 251 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
 252 {
 253         int size;
 254
 255         size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 256                         / sizeof(struct ext4_extent_idx);
 257 #ifdef AGGRESSIVE_TEST
 258         if (!check && size > 5)
 259                 size = 5;
 260 #endif
 261         return size;
 262 }
 263
 264 static inline int ext4_ext_space_root(struct inode *inode, int check)
 265 {
 266         int size;
 267
 268         size = sizeof(EXT4_I(inode)->i_data);
 269         size -= sizeof(struct ext4_extent_header);
 270         size /= sizeof(struct ext4_extent);
 271 #ifdef AGGRESSIVE_TEST
 272         if (!check && size > 3)
 273                 size = 3;
 274 #endif
 275         return size;
 276 }
 277
 278 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 279 {
 280         int size;
 281
 282         size = sizeof(EXT4_I(inode)->i_data);
 283         size -= sizeof(struct ext4_extent_header);
 284         size /= sizeof(struct ext4_extent_idx);
 285 #ifdef AGGRESSIVE_TEST
 286         if (!check && size > 4)
 287                 size = 4;
 288 #endif
 289         return size;
 290 }
 291
 292 /*
 293  * Calculate the number of metadata blocks needed
 294  * to allocate @blocks
 295  * Worse case is one block per extent
 296  */
 297 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
 298 {
 299         struct ext4_inode_info *ei = EXT4_I(inode);
 300         int idxs;
 301
 302         idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
 303                 / sizeof(struct ext4_extent_idx));
 304
 305         /*
 306          * If the new delayed allocation block is contiguous with the
 307          * previous da block, it can share index blocks with the
 308          * previous block, so we only need to allocate a new index
 309          * block every idxs leaf blocks.  At ldxs**2 blocks, we need
 310          * an additional index block, and at ldxs**3 blocks, yet
 311          * another index blocks.
 312          */
 313         if (ei->i_da_metadata_calc_len &&
 314             ei->i_da_metadata_calc_last_lblock+1 == lblock) {
 315                 int num = 0;
 316
 317                 if ((ei->i_da_metadata_calc_len % idxs) == 0)
 318                         num++;
 319                 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
 320                         num++;
 321                 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
 322                         num++;
 323                         ei->i_da_metadata_calc_len = 0;
 324                 } else
 325                         ei->i_da_metadata_calc_len++;
 326                 ei->i_da_metadata_calc_last_lblock++;
 327                 return num;
 328         }
 329
 330         /*
 331          * In the worst case we need a new set of index blocks at
 332          * every level of the inode's extent tree.
 333          */
 334         ei->i_da_metadata_calc_len = 1;
 335         ei->i_da_metadata_calc_last_lblock = lblock;
 336         return ext_depth(inode) + 1;
 337 }
 338
 339 static int
 340 ext4_ext_max_entries(struct inode *inode, int depth)
 341 {
 342         int max;
 343
 344         if (depth == ext_depth(inode)) {
 345                 if (depth == 0)
 346                         max = ext4_ext_space_root(inode, 1);
 347                 else
 348                         max = ext4_ext_space_root_idx(inode, 1);
 349         } else {
 350                 if (depth == 0)
 351                         max = ext4_ext_space_block(inode, 1);
 352                 else
 353                         max = ext4_ext_space_block_idx(inode, 1);
 354         }
 355
 356         return max;
 357 }
 358
 359 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
 360 {
 361         ext4_fsblk_t block = ext4_ext_pblock(ext);
 362         int len = ext4_ext_get_actual_len(ext);
 363         ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
 364         ext4_lblk_t last = lblock + len - 1;
 365
 366         if (lblock > last)
 367                 return 0;
 368         return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
 369 }
 370
 371 static int ext4_valid_extent_idx(struct inode *inode,
 372                                 struct ext4_extent_idx *ext_idx)
 373 {
 374         ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
 375
 376         return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
 377 }
 378
 379 static int ext4_valid_extent_entries(struct inode *inode,
 380                                 struct ext4_extent_header *eh,
 381                                 int depth)
 382 {
 383         unsigned short entries;
 384         if (eh->eh_entries == 0)
 385                 return 1;
 386
 387         entries = le16_to_cpu(eh->eh_entries);
 388
 389         if (depth == 0) {
 390                 /* leaf entries */
 391                 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
 392                 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 393                 ext4_fsblk_t pblock = 0;
 394                 ext4_lblk_t lblock = 0;
 395                 ext4_lblk_t prev = 0;
 396                 int len = 0;
 397                 while (entries) {
 398                         if (!ext4_valid_extent(inode, ext))
 399                                 return 0;
 400
 401                         /* Check for overlapping extents */
 402                         lblock = le32_to_cpu(ext->ee_block);
 403                         len = ext4_ext_get_actual_len(ext);
 404                         if ((lblock <= prev) && prev) {
 405                                 pblock = ext4_ext_pblock(ext);
 406                                 es->s_last_error_block = cpu_to_le64(pblock);
 407                                 return 0;
 408                         }
 409                         ext++;
 410                         entries--;
 411                         prev = lblock + len - 1;
 412                 }
 413         } else {
 414                 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
 415                 while (entries) {
 416                         if (!ext4_valid_extent_idx(inode, ext_idx))
 417                                 return 0;
 418                         ext_idx++;
 419                         entries--;
 420                 }
 421         }
 422         return 1;
 423 }
 424
 425 static int __ext4_ext_check(const char *function, unsigned int line,
 426                             struct inode *inode, struct ext4_extent_header *eh,
 427                             int depth, ext4_fsblk_t pblk)
 428 {
 429         const char *error_msg;
 430         int max = 0;
 431
 432         if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
 433                 error_msg = "invalid magic";
 434                 goto corrupted;
 435         }
 436         if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
 437                 error_msg = "unexpected eh_depth";
 438                 goto corrupted;
 439         }
 440         if (unlikely(eh->eh_max == 0)) {
 441                 error_msg = "invalid eh_max";
 442                 goto corrupted;
 443         }
 444         max = ext4_ext_max_entries(inode, depth);
 445         if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
 446                 error_msg = "too large eh_max";
 447                 goto corrupted;
 448         }
 449         if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
 450                 error_msg = "invalid eh_entries";
 451                 goto corrupted;
 452         }
 453         if (!ext4_valid_extent_entries(inode, eh, depth)) {
 454                 error_msg = "invalid extent entries";
 455                 goto corrupted;
 456         }
 457         /* Verify checksum on non-root extent tree nodes */
 458         if (ext_depth(inode) != depth &&
 459             !ext4_extent_block_csum_verify(inode, eh)) {
 460                 error_msg = "extent tree corrupted";
 461                 goto corrupted;
 462         }
 463         return 0;
 464
 465 corrupted:
 466         ext4_error_inode(inode, function, line, 0,
 467                          "pblk %llu bad header/extent: %s - magic %x, "
 468                          "entries %u, max %u(%u), depth %u(%u)",
 469                          (unsigned long long) pblk, error_msg,
 470                          le16_to_cpu(eh->eh_magic),
 471                          le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
 472                          max, le16_to_cpu(eh->eh_depth), depth);
 473         return -EIO;
 474 }
 475
 476 #define ext4_ext_check(inode, eh, depth, pblk)                  \
 477         __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
 478
 479 int ext4_ext_check_inode(struct inode *inode)
 480 {
 481         return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
 482 }
 483
 484 static struct buffer_head *
 485 __read_extent_tree_block(const char *function, unsigned int line,
 486                          struct inode *inode, ext4_fsblk_t pblk, int depth,
 487                          int flags)
 488 {
 489         struct buffer_head              *bh;
 490         int                             err;
 491
 492         bh = sb_getblk(inode->i_sb, pblk);
 493         if (unlikely(!bh))
 494                 return ERR_PTR(-ENOMEM);
 495
 496         if (!bh_uptodate_or_lock(bh)) {
 497                 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
 498                 err = bh_submit_read(bh);
 499                 if (err < 0)
 500                         goto errout;
 501         }
 502         if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
 503                 return bh;
 504         err = __ext4_ext_check(function, line, inode,
 505                                ext_block_hdr(bh), depth, pblk);
 506         if (err)
 507                 goto errout;
 508         set_buffer_verified(bh);
 509         /*
 510          * If this is a leaf block, cache all of its entries
 511          */
 512         if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
 513                 struct ext4_extent_header *eh = ext_block_hdr(bh);
 514                 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
 515                 ext4_lblk_t prev = 0;
 516                 int i;
 517
 518                 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
 519                         unsigned int status = EXTENT_STATUS_WRITTEN;
 520                         ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
 521                         int len = ext4_ext_get_actual_len(ex);
 522
 523                         if (prev && (prev != lblk))
 524                                 ext4_es_cache_extent(inode, prev,
 525                                                      lblk - prev, ~0,
 526                                                      EXTENT_STATUS_HOLE);
 527
 528                         if (ext4_ext_is_uninitialized(ex))
 529                                 status = EXTENT_STATUS_UNWRITTEN;
 530                         ext4_es_cache_extent(inode, lblk, len,
 531                                              ext4_ext_pblock(ex), status);
 532                         prev = lblk + len;
 533                 }
 534         }
 535         return bh;
 536 errout:
 537         put_bh(bh);
 538         return ERR_PTR(err);
 539
 540 }
 541
 542 #define read_extent_tree_block(inode, pblk, depth, flags)               \
 543         __read_extent_tree_block(__func__, __LINE__, (inode), (pblk),   \
 544                                  (depth), (flags))
 545
 546 /*
 547  * This function is called to cache a file's extent information in the
 548  * extent status tree
 549  */
 550 int ext4_ext_precache(struct inode *inode)
 551 {
 552         struct ext4_inode_info *ei = EXT4_I(inode);
 553         struct ext4_ext_path *path = NULL;
 554         struct buffer_head *bh;
 555         int i = 0, depth, ret = 0;
 556
 557         if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 558                 return 0;       /* not an extent-mapped inode */
 559
 560         down_read(&ei->i_data_sem);
 561         depth = ext_depth(inode);
 562
 563         path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
 564                        GFP_NOFS);
 565         if (path == NULL) {
 566                 up_read(&ei->i_data_sem);
 567                 return -ENOMEM;
 568         }
 569
 570         /* Don't cache anything if there are no external extent blocks */
 571         if (depth == 0)
 572                 goto out;
 573         path[0].p_hdr = ext_inode_hdr(inode);
 574         ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
 575         if (ret)
 576                 goto out;
 577         path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
 578         while (i >= 0) {
 579                 /*
 580                  * If this is a leaf block or we've reached the end of
 581                  * the index block, go up
 582                  */
 583                 if ((i == depth) ||
 584                     path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
 585                         brelse(path[i].p_bh);
 586                         path[i].p_bh = NULL;
 587                         i--;
 588                         continue;
 589                 }
 590                 bh = read_extent_tree_block(inode,
 591                                             ext4_idx_pblock(path[i].p_idx++),
 592                                             depth - i - 1,
 593                                             EXT4_EX_FORCE_CACHE);
 594                 if (IS_ERR(bh)) {
 595                         ret = PTR_ERR(bh);
 596                         break;
 597                 }
 598                 i++;
 599                 path[i].p_bh = bh;
 600                 path[i].p_hdr = ext_block_hdr(bh);
 601                 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
 602         }
 603         ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
 604 out:
 605         up_read(&ei->i_data_sem);
 606         ext4_ext_drop_refs(path);
 607         kfree(path);
 608         return ret;
 609 }
 610
 611 #ifdef EXT_DEBUG
 612 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 613 {
 614         int k, l = path->p_depth;
 615
 616         ext_debug("path:");
 617         for (k = 0; k <= l; k++, path++) {
 618                 if (path->p_idx) {
 619                   ext_debug("  %d->%llu", le32_to_cpu(path->p_idx->ei_block),
 620                             ext4_idx_pblock(path->p_idx));
 621                 } else if (path->p_ext) {
 622                         ext_debug("  %d:[%d]%d:%llu ",
 623                                   le32_to_cpu(path->p_ext->ee_block),
 624                                   ext4_ext_is_uninitialized(path->p_ext),
 625                                   ext4_ext_get_actual_len(path->p_ext),
 626                                   ext4_ext_pblock(path->p_ext));
 627                 } else
 628                         ext_debug("  []");
 629         }
 630         ext_debug("\n");
 631 }
 632
 633 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 634 {
 635         int depth = ext_depth(inode);
 636         struct ext4_extent_header *eh;
 637         struct ext4_extent *ex;
 638         int i;
 639
 640         if (!path)
 641                 return;
 642
 643         eh = path[depth].p_hdr;
 644         ex = EXT_FIRST_EXTENT(eh);
 645
 646         ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
 647
 648         for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
 649                 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
 650                           ext4_ext_is_uninitialized(ex),
 651                           ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
 652         }
 653         ext_debug("\n");
 654 }
 655
 656 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
 657                         ext4_fsblk_t newblock, int level)
 658 {
 659         int depth = ext_depth(inode);
 660         struct ext4_extent *ex;
 661
 662         if (depth != level) {
 663                 struct ext4_extent_idx *idx;
 664                 idx = path[level].p_idx;
 665                 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
 666                         ext_debug("%d: move %d:%llu in new index %llu\n", level,
 667                                         le32_to_cpu(idx->ei_block),
 668                                         ext4_idx_pblock(idx),
 669                                         newblock);
 670                         idx++;
 671                 }
 672
 673                 return;
 674         }
 675
 676         ex = path[depth].p_ext;
 677         while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
 678                 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
 679                                 le32_to_cpu(ex->ee_block),
 680                                 ext4_ext_pblock(ex),
 681                                 ext4_ext_is_uninitialized(ex),
 682                                 ext4_ext_get_actual_len(ex),
 683                                 newblock);
 684                 ex++;
 685         }
 686 }
 687
 688 #else
 689 #define ext4_ext_show_path(inode, path)
 690 #define ext4_ext_show_leaf(inode, path)
 691 #define ext4_ext_show_move(inode, path, newblock, level)
 692 #endif
 693
 694 void ext4_ext_drop_refs(struct ext4_ext_path *path)
 695 {
 696         int depth = path->p_depth;
 697         int i;
 698
 699         for (i = 0; i <= depth; i++, path++)
 700                 if (path->p_bh) {
 701                         brelse(path->p_bh);
 702                         path->p_bh = NULL;
 703                 }
 704 }
 705
 706 /*
 707  * ext4_ext_binsearch_idx:
 708  * binary search for the closest index of the given block
 709  * the header must be checked before calling this
 710  */
 711 static void
 712 ext4_ext_binsearch_idx(struct inode *inode,
 713                         struct ext4_ext_path *path, ext4_lblk_t block)
 714 {
 715         struct ext4_extent_header *eh = path->p_hdr;
 716         struct ext4_extent_idx *r, *l, *m;
 717
 718
 719         ext_debug("binsearch for %u(idx):  ", block);
 720
 721         l = EXT_FIRST_INDEX(eh) + 1;
 722         r = EXT_LAST_INDEX(eh);
 723         while (l <= r) {
 724                 m = l + (r - l) / 2;
 725                 if (block < le32_to_cpu(m->ei_block))
 726                         r = m - 1;
 727                 else
 728                         l = m + 1;
 729                 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
 730                                 m, le32_to_cpu(m->ei_block),
 731                                 r, le32_to_cpu(r->ei_block));
 732         }
 733
 734         path->p_idx = l - 1;
 735         ext_debug("  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 736                   ext4_idx_pblock(path->p_idx));
 737
 738 #ifdef CHECK_BINSEARCH
 739         {
 740                 struct ext4_extent_idx *chix, *ix;
 741                 int k;
 742
 743                 chix = ix = EXT_FIRST_INDEX(eh);
 744                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
 745                   if (k != 0 &&
 746                       le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
 747                                 printk(KERN_DEBUG "k=%d, ix=0x%p, "
 748                                        "first=0x%p\n", k,
 749                                        ix, EXT_FIRST_INDEX(eh));
 750                                 printk(KERN_DEBUG "%u <= %u\n",
 751                                        le32_to_cpu(ix->ei_block),
 752                                        le32_to_cpu(ix[-1].ei_block));
 753                         }
 754                         BUG_ON(k && le32_to_cpu(ix->ei_block)
 755                                            <= le32_to_cpu(ix[-1].ei_block));
 756                         if (block < le32_to_cpu(ix->ei_block))
 757                                 break;
 758                         chix = ix;
 759                 }
 760                 BUG_ON(chix != path->p_idx);
 761         }
 762 #endif
 763
 764 }
 765
 766 /*
 767  * ext4_ext_binsearch:
 768  * binary search for closest extent of the given block
 769  * the header must be checked before calling this
 770  */
 771 static void
 772 ext4_ext_binsearch(struct inode *inode,
 773                 struct ext4_ext_path *path, ext4_lblk_t block)
 774 {
 775         struct ext4_extent_header *eh = path->p_hdr;
 776         struct ext4_extent *r, *l, *m;
 777
 778         if (eh->eh_entries == 0) {
 779                 /*
 780                  * this leaf is empty:
 781                  * we get such a leaf in split/add case
 782                  */
 783                 return;
 784         }
 785
 786         ext_debug("binsearch for %u:  ", block);
 787
 788         l = EXT_FIRST_EXTENT(eh) + 1;
 789         r = EXT_LAST_EXTENT(eh);
 790
 791         while (l <= r) {
 792                 m = l + (r - l) / 2;
 793                 if (block < le32_to_cpu(m->ee_block))
 794                         r = m - 1;
 795                 else
 796                         l = m + 1;
 797                 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
 798                                 m, le32_to_cpu(m->ee_block),
 799                                 r, le32_to_cpu(r->ee_block));
 800         }
 801
 802         path->p_ext = l - 1;
 803         ext_debug("  -> %d:%llu:[%d]%d ",
 804                         le32_to_cpu(path->p_ext->ee_block),
 805                         ext4_ext_pblock(path->p_ext),
 806                         ext4_ext_is_uninitialized(path->p_ext),
 807                         ext4_ext_get_actual_len(path->p_ext));
 808
 809 #ifdef CHECK_BINSEARCH
 810         {
 811                 struct ext4_extent *chex, *ex;
 812                 int k;
 813
 814                 chex = ex = EXT_FIRST_EXTENT(eh);
 815                 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
 816                         BUG_ON(k && le32_to_cpu(ex->ee_block)
 817                                           <= le32_to_cpu(ex[-1].ee_block));
 818                         if (block < le32_to_cpu(ex->ee_block))
 819                                 break;
 820                         chex = ex;
 821                 }
 822                 BUG_ON(chex != path->p_ext);
 823         }
 824 #endif
 825
 826 }
 827
 828 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 829 {
 830         struct ext4_extent_header *eh;
 831
 832         eh = ext_inode_hdr(inode);
 833         eh->eh_depth = 0;
 834         eh->eh_entries = 0;
 835         eh->eh_magic = EXT4_EXT_MAGIC;
 836         eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
 837         ext4_mark_inode_dirty(handle, inode);
 838         return 0;
 839 }
 840
 841 struct ext4_ext_path *
 842 ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 843                      struct ext4_ext_path *path, int flags)
 844 {
 845         struct ext4_extent_header *eh;
 846         struct buffer_head *bh;
 847         short int depth, i, ppos = 0, alloc = 0;
 848         int ret;
 849
 850         eh = ext_inode_hdr(inode);
 851         depth = ext_depth(inode);
 852
 853         /* account possible depth increase */
 854         if (!path) {
 855                 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
 856                                 GFP_NOFS);
 857                 if (!path)
 858                         return ERR_PTR(-ENOMEM);
 859                 alloc = 1;
 860         }
 861         path[0].p_hdr = eh;
 862         path[0].p_bh = NULL;
 863
 864         i = depth;
 865         /* walk through the tree */
 866         while (i) {
 867                 ext_debug("depth %d: num %d, max %d\n",
 868                           ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
 869
 870                 ext4_ext_binsearch_idx(inode, path + ppos, block);
 871                 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
 872                 path[ppos].p_depth = i;
 873                 path[ppos].p_ext = NULL;
 874
 875                 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
 876                                             flags);
 877                 if (IS_ERR(bh)) {
 878                         ret = PTR_ERR(bh);
 879                         goto err;
 880                 }
 881
 882                 eh = ext_block_hdr(bh);
 883                 ppos++;
 884                 if (unlikely(ppos > depth)) {
 885                         put_bh(bh);
 886                         EXT4_ERROR_INODE(inode,
 887                                          "ppos %d > depth %d", ppos, depth);
 888                         ret = -EIO;
 889                         goto err;
 890                 }
 891                 path[ppos].p_bh = bh;
 892                 path[ppos].p_hdr = eh;
 893         }
 894
 895         path[ppos].p_depth = i;
 896         path[ppos].p_ext = NULL;
 897         path[ppos].p_idx = NULL;
 898
 899         /* find extent */
 900         ext4_ext_binsearch(inode, path + ppos, block);
 901         /* if not an empty leaf */
 902         if (path[ppos].p_ext)
 903                 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
 904
 905         ext4_ext_show_path(inode, path);
 906
 907         return path;
 908
 909 err:
 910         ext4_ext_drop_refs(path);
 911         if (alloc)
 912                 kfree(path);
 913         return ERR_PTR(ret);
 914 }
 915
 916 /*
 917  * ext4_ext_insert_index:
 918  * insert new index [@logical;@ptr] into the block at @curp;
 919  * check where to insert: before @curp or after @curp
 920  */
 921 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 922                                  struct ext4_ext_path *curp,
 923                                  int logical, ext4_fsblk_t ptr)
 924 {
 925         struct ext4_extent_idx *ix;
 926         int len, err;
 927
 928         err = ext4_ext_get_access(handle, inode, curp);
 929         if (err)
 930                 return err;
 931
 932         if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
 933                 EXT4_ERROR_INODE(inode,
 934                                  "logical %d == ei_block %d!",
 935                                  logical, le32_to_cpu(curp->p_idx->ei_block));
 936                 return -EIO;
 937         }
 938
 939         if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
 940                              >= le16_to_cpu(curp->p_hdr->eh_max))) {
 941                 EXT4_ERROR_INODE(inode,
 942                                  "eh_entries %d >= eh_max %d!",
 943                                  le16_to_cpu(curp->p_hdr->eh_entries),
 944                                  le16_to_cpu(curp->p_hdr->eh_max));
 945                 return -EIO;
 946         }
 947
 948         if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
 949                 /* insert after */
 950                 ext_debug("insert new index %d after: %llu\n", logical, ptr);
 951                 ix = curp->p_idx + 1;
 952         } else {
 953                 /* insert before */
 954                 ext_debug("insert new index %d before: %llu\n", logical, ptr);
 955                 ix = curp->p_idx;
 956         }
 957
 958         len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
 959         BUG_ON(len < 0);
 960         if (len > 0) {
 961                 ext_debug("insert new index %d: "
 962                                 "move %d indices from 0x%p to 0x%p\n",
 963                                 logical, len, ix, ix + 1);
 964                 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
 965         }
 966
 967         if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
 968                 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
 969                 return -EIO;
 970         }
 971
 972         ix->ei_block = cpu_to_le32(logical);
 973         ext4_idx_store_pblock(ix, ptr);
 974         le16_add_cpu(&curp->p_hdr->eh_entries, 1);
 975
 976         if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
 977                 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
 978                 return -EIO;
 979         }
 980
 981         err = ext4_ext_dirty(handle, inode, curp);
 982         ext4_std_error(inode->i_sb, err);
 983
 984         return err;
 985 }
 986
 987 /*
 988  * ext4_ext_split:
 989  * inserts new subtree into the path, using free index entry
 990  * at depth @at:
 991  * - allocates all needed blocks (new leaf and all intermediate index blocks)
 992  * - makes decision where to split
 993  * - moves remaining extents and index entries (right to the split point)
 994  *   into the newly allocated blocks
 995  * - initializes subtree
 996  */
 997 static int ext4_ext_split(handle_t *handle, struct inode *inode,
 998                           unsigned int flags,
 999                           struct ext4_ext_path *path,
1000                           struct ext4_extent *newext, int at)
1001 {
1002         struct buffer_head *bh = NULL;
1003         int depth = ext_depth(inode);
1004         struct ext4_extent_header *neh;
1005         struct ext4_extent_idx *fidx;
1006         int i = at, k, m, a;
1007         ext4_fsblk_t newblock, oldblock;
1008         __le32 border;
1009         ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1010         int err = 0;
1011
1012         /* make decision: where to split? */
1013         /* FIXME: now decision is simplest: at current extent */
1014
1015         /* if current leaf will be split, then we should use
1016          * border from split point */
1017         if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1018                 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1019                 return -EIO;
1020         }
1021         if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1022                 border = path[depth].p_ext[1].ee_block;
1023                 ext_debug("leaf will be split."
1024                                 " next leaf starts at %d\n",
1025                                   le32_to_cpu(border));
1026         } else {
1027                 border = newext->ee_block;
1028                 ext_debug("leaf will be added."
1029                                 " next leaf starts at %d\n",
1030                                 le32_to_cpu(border));
1031         }
1032
1033         /*
1034          * If error occurs, then we break processing
1035          * and mark filesystem read-only. index won't
1036          * be inserted and tree will be in consistent
1037          * state. Next mount will repair buffers too.
1038          */
1039
1040         /*
1041          * Get array to track all allocated blocks.
1042          * We need this to handle errors and free blocks
1043          * upon them.
1044          */
1045         ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1046         if (!ablocks)
1047                 return -ENOMEM;
1048
1049         /* allocate all needed blocks */
1050         ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1051         for (a = 0; a < depth - at; a++) {
1052                 newblock = ext4_ext_new_meta_block(handle, inode, path,
1053                                                    newext, &err, flags);
1054                 if (newblock == 0)
1055                         goto cleanup;
1056                 ablocks[a] = newblock;
1057         }
1058
1059         /* initialize new leaf */
1060         newblock = ablocks[--a];
1061         if (unlikely(newblock == 0)) {
1062                 EXT4_ERROR_INODE(inode, "newblock == 0!");
1063                 err = -EIO;
1064                 goto cleanup;
1065         }
1066         bh = sb_getblk(inode->i_sb, newblock);
1067         if (unlikely(!bh)) {
1068                 err = -ENOMEM;
1069                 goto cleanup;
1070         }
1071         lock_buffer(bh);
1072
1073         err = ext4_journal_get_create_access(handle, bh);
1074         if (err)
1075                 goto cleanup;
1076
1077         neh = ext_block_hdr(bh);
1078         neh->eh_entries = 0;
1079         neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1080         neh->eh_magic = EXT4_EXT_MAGIC;
1081         neh->eh_depth = 0;
1082
1083         /* move remainder of path[depth] to the new leaf */
1084         if (unlikely(path[depth].p_hdr->eh_entries !=
1085                      path[depth].p_hdr->eh_max)) {
1086                 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1087                                  path[depth].p_hdr->eh_entries,
1088                                  path[depth].p_hdr->eh_max);
1089                 err = -EIO;
1090                 goto cleanup;
1091         }
1092         /* start copy from next extent */
1093         m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1094         ext4_ext_show_move(inode, path, newblock, depth);
1095         if (m) {
1096                 struct ext4_extent *ex;
1097                 ex = EXT_FIRST_EXTENT(neh);
1098                 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1099                 le16_add_cpu(&neh->eh_entries, m);
1100         }
1101
1102         ext4_extent_block_csum_set(inode, neh);
1103         set_buffer_uptodate(bh);
1104         unlock_buffer(bh);
1105
1106         err = ext4_handle_dirty_metadata(handle, inode, bh);
1107         if (err)
1108                 goto cleanup;
1109         brelse(bh);
1110         bh = NULL;
1111
1112         /* correct old leaf */
1113         if (m) {
1114                 err = ext4_ext_get_access(handle, inode, path + depth);
1115                 if (err)
1116                         goto cleanup;
1117                 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1118                 err = ext4_ext_dirty(handle, inode, path + depth);
1119                 if (err)
1120                         goto cleanup;
1121
1122         }
1123
1124         /* create intermediate indexes */
1125         k = depth - at - 1;
1126         if (unlikely(k < 0)) {
1127                 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1128                 err = -EIO;
1129                 goto cleanup;
1130         }
1131         if (k)
1132                 ext_debug("create %d intermediate indices\n", k);
1133         /* insert new index into current index block */
1134         /* current depth stored in i var */
1135         i = depth - 1;
1136         while (k--) {
1137                 oldblock = newblock;
1138                 newblock = ablocks[--a];
1139                 bh = sb_getblk(inode->i_sb, newblock);
1140                 if (unlikely(!bh)) {
1141                         err = -ENOMEM;
1142                         goto cleanup;
1143                 }
1144                 lock_buffer(bh);
1145
1146                 err = ext4_journal_get_create_access(handle, bh);
1147                 if (err)
1148                         goto cleanup;
1149
1150                 neh = ext_block_hdr(bh);
1151                 neh->eh_entries = cpu_to_le16(1);
1152                 neh->eh_magic = EXT4_EXT_MAGIC;
1153                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1154                 neh->eh_depth = cpu_to_le16(depth - i);
1155                 fidx = EXT_FIRST_INDEX(neh);
1156                 fidx->ei_block = border;
1157                 ext4_idx_store_pblock(fidx, oldblock);
1158
1159                 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1160                                 i, newblock, le32_to_cpu(border), oldblock);
1161
1162                 /* move remainder of path[i] to the new index block */
1163                 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1164                                         EXT_LAST_INDEX(path[i].p_hdr))) {
1165                         EXT4_ERROR_INODE(inode,
1166                                          "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1167                                          le32_to_cpu(path[i].p_ext->ee_block));
1168                         err = -EIO;
1169                         goto cleanup;
1170                 }
1171                 /* start copy indexes */
1172                 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1173                 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1174                                 EXT_MAX_INDEX(path[i].p_hdr));
1175                 ext4_ext_show_move(inode, path, newblock, i);
1176                 if (m) {
1177                         memmove(++fidx, path[i].p_idx,
1178                                 sizeof(struct ext4_extent_idx) * m);
1179                         le16_add_cpu(&neh->eh_entries, m);
1180                 }
1181                 ext4_extent_block_csum_set(inode, neh);
1182                 set_buffer_uptodate(bh);
1183                 unlock_buffer(bh);
1184
1185                 err = ext4_handle_dirty_metadata(handle, inode, bh);
1186                 if (err)
1187                         goto cleanup;
1188                 brelse(bh);
1189                 bh = NULL;
1190
1191                 /* correct old index */
1192                 if (m) {
1193                         err = ext4_ext_get_access(handle, inode, path + i);
1194                         if (err)
1195                                 goto cleanup;
1196                         le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1197                         err = ext4_ext_dirty(handle, inode, path + i);
1198                         if (err)
1199                                 goto cleanup;
1200                 }
1201
1202                 i--;
1203         }
1204
1205         /* insert new index */
1206         err = ext4_ext_insert_index(handle, inode, path + at,
1207                                     le32_to_cpu(border), newblock);
1208
1209 cleanup:
1210         if (bh) {
1211                 if (buffer_locked(bh))
1212                         unlock_buffer(bh);
1213                 brelse(bh);
1214         }
1215
1216         if (err) {
1217                 /* free all allocated blocks in error case */
1218                 for (i = 0; i < depth; i++) {
1219                         if (!ablocks[i])
1220                                 continue;
1221                         ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1222                                          EXT4_FREE_BLOCKS_METADATA);
1223                 }
1224         }
1225         kfree(ablocks);
1226
1227         return err;
1228 }
1229
1230 /*
1231  * ext4_ext_grow_indepth:
1232  * implements tree growing procedure:
1233  * - allocates new block
1234  * - moves top-level data (index block or leaf) into the new block
1235  * - initializes new top-level, creating index that points to the
1236  *   just created block
1237  */
1238 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1239                                  unsigned int flags,
1240                                  struct ext4_extent *newext)
1241 {
1242         struct ext4_extent_header *neh;
1243         struct buffer_head *bh;
1244         ext4_fsblk_t newblock;
1245         int err = 0;
1246
1247         newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1248                 newext, &err, flags);
1249         if (newblock == 0)
1250                 return err;
1251
1252         bh = sb_getblk(inode->i_sb, newblock);
1253         if (unlikely(!bh))
1254                 return -ENOMEM;
1255         lock_buffer(bh);
1256
1257         err = ext4_journal_get_create_access(handle, bh);
1258         if (err) {
1259                 unlock_buffer(bh);
1260                 goto out;
1261         }
1262
1263         /* move top-level index/leaf into new block */
1264         memmove(bh->b_data, EXT4_I(inode)->i_data,
1265                 sizeof(EXT4_I(inode)->i_data));
1266
1267         /* set size of new block */
1268         neh = ext_block_hdr(bh);
1269         /* old root could have indexes or leaves
1270          * so calculate e_max right way */
1271         if (ext_depth(inode))
1272                 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1273         else
1274                 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1275         neh->eh_magic = EXT4_EXT_MAGIC;
1276         ext4_extent_block_csum_set(inode, neh);
1277         set_buffer_uptodate(bh);
1278         unlock_buffer(bh);
1279
1280         err = ext4_handle_dirty_metadata(handle, inode, bh);
1281         if (err)
1282                 goto out;
1283
1284         /* Update top-level index: num,max,pointer */
1285         neh = ext_inode_hdr(inode);
1286         neh->eh_entries = cpu_to_le16(1);
1287         ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1288         if (neh->eh_depth == 0) {
1289                 /* Root extent block becomes index block */
1290                 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1291                 EXT_FIRST_INDEX(neh)->ei_block =
1292                         EXT_FIRST_EXTENT(neh)->ee_block;
1293         }
1294         ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1295                   le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1296                   le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1297                   ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1298
1299         le16_add_cpu(&neh->eh_depth, 1);
1300         ext4_mark_inode_dirty(handle, inode);
1301 out:
1302         brelse(bh);
1303
1304         return err;
1305 }
1306
1307 /*
1308  * ext4_ext_create_new_leaf:
1309  * finds empty index and adds new leaf.
1310  * if no free index is found, then it requests in-depth growing.
1311  */
1312 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1313                                     unsigned int mb_flags,
1314                                     unsigned int gb_flags,
1315                                     struct ext4_ext_path *path,
1316                                     struct ext4_extent *newext)
1317 {
1318         struct ext4_ext_path *curp;
1319         int depth, i, err = 0;
1320
1321 repeat:
1322         i = depth = ext_depth(inode);
1323
1324         /* walk up to the tree and look for free index entry */
1325         curp = path + depth;
1326         while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1327                 i--;
1328                 curp--;
1329         }
1330
1331         /* we use already allocated block for index block,
1332          * so subsequent data blocks should be contiguous */
1333         if (EXT_HAS_FREE_INDEX(curp)) {
1334                 /* if we found index with free entry, then use that
1335                  * entry: create all needed subtree and add new leaf */
1336                 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1337                 if (err)
1338                         goto out;
1339
1340                 /* refill path */
1341                 ext4_ext_drop_refs(path);
1342                 path = ext4_ext_find_extent(inode,
1343                                     (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1344                                     path, gb_flags);
1345                 if (IS_ERR(path))
1346                         err = PTR_ERR(path);
1347         } else {
1348                 /* tree is full, time to grow in depth */
1349                 err = ext4_ext_grow_indepth(handle, inode, mb_flags, newext);
1350                 if (err)
1351                         goto out;
1352
1353                 /* refill path */
1354                 ext4_ext_drop_refs(path);
1355                 path = ext4_ext_find_extent(inode,
1356                                    (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1357                                     path, gb_flags);
1358                 if (IS_ERR(path)) {
1359                         err = PTR_ERR(path);
1360                         goto out;
1361                 }
1362
1363                 /*
1364                  * only first (depth 0 -> 1) produces free space;
1365                  * in all other cases we have to split the grown tree
1366                  */
1367                 depth = ext_depth(inode);
1368                 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1369                         /* now we need to split */
1370                         goto repeat;
1371                 }
1372         }
1373
1374 out:
1375         return err;
1376 }
1377
1378 /*
1379  * search the closest allocated block to the left for *logical
1380  * and returns it at @logical + it's physical address at @phys
1381  * if *logical is the smallest allocated block, the function
1382  * returns 0 at @phys
1383  * return value contains 0 (success) or error code
1384  */
1385 static int ext4_ext_search_left(struct inode *inode,
1386                                 struct ext4_ext_path *path,
1387                                 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1388 {
1389         struct ext4_extent_idx *ix;
1390         struct ext4_extent *ex;
1391         int depth, ee_len;
1392
1393         if (unlikely(path == NULL)) {
1394                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1395                 return -EIO;
1396         }
1397         depth = path->p_depth;
1398         *phys = 0;
1399
1400         if (depth == 0 && path->p_ext == NULL)
1401                 return 0;
1402
1403         /* usually extent in the path covers blocks smaller
1404          * then *logical, but it can be that extent is the
1405          * first one in the file */
1406
1407         ex = path[depth].p_ext;
1408         ee_len = ext4_ext_get_actual_len(ex);
1409         if (*logical < le32_to_cpu(ex->ee_block)) {
1410                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1411                         EXT4_ERROR_INODE(inode,
1412                                          "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1413                                          *logical, le32_to_cpu(ex->ee_block));
1414                         return -EIO;
1415                 }
1416                 while (--depth >= 0) {
1417                         ix = path[depth].p_idx;
1418                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1419                                 EXT4_ERROR_INODE(inode,
1420                                   "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1421                                   ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1422                                   EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1423                 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1424                                   depth);
1425                                 return -EIO;
1426                         }
1427                 }
1428                 return 0;
1429         }
1430
1431         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1432                 EXT4_ERROR_INODE(inode,
1433                                  "logical %d < ee_block %d + ee_len %d!",
1434                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1435                 return -EIO;
1436         }
1437
1438         *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1439         *phys = ext4_ext_pblock(ex) + ee_len - 1;
1440         return 0;
1441 }
1442
1443 /*
1444  * search the closest allocated block to the right for *logical
1445  * and returns it at @logical + it's physical address at @phys
1446  * if *logical is the largest allocated block, the function
1447  * returns 0 at @phys
1448  * return value contains 0 (success) or error code
1449  */
1450 static int ext4_ext_search_right(struct inode *inode,
1451                                  struct ext4_ext_path *path,
1452                                  ext4_lblk_t *logical, ext4_fsblk_t *phys,
1453                                  struct ext4_extent **ret_ex)
1454 {
1455         struct buffer_head *bh = NULL;
1456         struct ext4_extent_header *eh;
1457         struct ext4_extent_idx *ix;
1458         struct ext4_extent *ex;
1459         ext4_fsblk_t block;
1460         int depth;      /* Note, NOT eh_depth; depth from top of tree */
1461         int ee_len;
1462
1463         if (unlikely(path == NULL)) {
1464                 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1465                 return -EIO;
1466         }
1467         depth = path->p_depth;
1468         *phys = 0;
1469
1470         if (depth == 0 && path->p_ext == NULL)
1471                 return 0;
1472
1473         /* usually extent in the path covers blocks smaller
1474          * then *logical, but it can be that extent is the
1475          * first one in the file */
1476
1477         ex = path[depth].p_ext;
1478         ee_len = ext4_ext_get_actual_len(ex);
1479         if (*logical < le32_to_cpu(ex->ee_block)) {
1480                 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1481                         EXT4_ERROR_INODE(inode,
1482                                          "first_extent(path[%d].p_hdr) != ex",
1483                                          depth);
1484                         return -EIO;
1485                 }
1486                 while (--depth >= 0) {
1487                         ix = path[depth].p_idx;
1488                         if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1489                                 EXT4_ERROR_INODE(inode,
1490                                                  "ix != EXT_FIRST_INDEX *logical %d!",
1491                                                  *logical);
1492                                 return -EIO;
1493                         }
1494                 }
1495                 goto found_extent;
1496         }
1497
1498         if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1499                 EXT4_ERROR_INODE(inode,
1500                                  "logical %d < ee_block %d + ee_len %d!",
1501                                  *logical, le32_to_cpu(ex->ee_block), ee_len);
1502                 return -EIO;
1503         }
1504
1505         if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1506                 /* next allocated block in this leaf */
1507                 ex++;
1508                 goto found_extent;
1509         }
1510
1511         /* go up and search for index to the right */
1512         while (--depth >= 0) {
1513                 ix = path[depth].p_idx;
1514                 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1515                         goto got_index;
1516         }
1517
1518         /* we've gone up to the root and found no index to the right */
1519         return 0;
1520
1521 got_index:
1522         /* we've found index to the right, let's
1523          * follow it and find the closest allocated
1524          * block to the right */
1525         ix++;
1526         block = ext4_idx_pblock(ix);
1527         while (++depth < path->p_depth) {
1528                 /* subtract from p_depth to get proper eh_depth */
1529                 bh = read_extent_tree_block(inode, block,
1530                                             path->p_depth - depth, 0);
1531                 if (IS_ERR(bh))
1532                         return PTR_ERR(bh);
1533                 eh = ext_block_hdr(bh);
1534                 ix = EXT_FIRST_INDEX(eh);
1535                 block = ext4_idx_pblock(ix);
1536                 put_bh(bh);
1537         }
1538
1539         bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1540         if (IS_ERR(bh))
1541                 return PTR_ERR(bh);
1542         eh = ext_block_hdr(bh);
1543         ex = EXT_FIRST_EXTENT(eh);
1544 found_extent:
1545         *logical = le32_to_cpu(ex->ee_block);
1546         *phys = ext4_ext_pblock(ex);
1547         *ret_ex = ex;
1548         if (bh)
1549                 put_bh(bh);
1550         return 0;
1551 }
1552
1553 /*
1554  * ext4_ext_next_allocated_block:
1555  * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1556  * NOTE: it considers block number from index entry as
1557  * allocated block. Thus, index entries have to be consistent
1558  * with leaves.
1559  */
1560 static ext4_lblk_t
1561 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1562 {
1563         int depth;
1564
1565         BUG_ON(path == NULL);
1566         depth = path->p_depth;
1567
1568         if (depth == 0 && path->p_ext == NULL)
1569                 return EXT_MAX_BLOCKS;
1570
1571         while (depth >= 0) {
1572                 if (depth == path->p_depth) {
1573                         /* leaf */
1574                         if (path[depth].p_ext &&
1575                                 path[depth].p_ext !=
1576                                         EXT_LAST_EXTENT(path[depth].p_hdr))
1577                           return le32_to_cpu(path[depth].p_ext[1].ee_block);
1578                 } else {
1579                         /* index */
1580                         if (path[depth].p_idx !=
1581                                         EXT_LAST_INDEX(path[depth].p_hdr))
1582                           return le32_to_cpu(path[depth].p_idx[1].ei_block);
1583                 }
1584                 depth--;
1585         }
1586
1587         return EXT_MAX_BLOCKS;
1588 }
1589
1590 /*
1591  * ext4_ext_next_leaf_block:
1592  * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1593  */
1594 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1595 {
1596         int depth;
1597
1598         BUG_ON(path == NULL);
1599         depth = path->p_depth;
1600
1601         /* zero-tree has no leaf blocks at all */
1602         if (depth == 0)
1603                 return EXT_MAX_BLOCKS;
1604
1605         /* go to index block */
1606         depth--;
1607
1608         while (depth >= 0) {
1609                 if (path[depth].p_idx !=
1610                                 EXT_LAST_INDEX(path[depth].p_hdr))
1611                         return (ext4_lblk_t)
1612                                 le32_to_cpu(path[depth].p_idx[1].ei_block);
1613                 depth--;
1614         }
1615
1616         return EXT_MAX_BLOCKS;
1617 }
1618
1619 /*
1620  * ext4_ext_correct_indexes:
1621  * if leaf gets modified and modified extent is first in the leaf,
1622  * then we have to correct all indexes above.
1623  * TODO: do we need to correct tree in all cases?
1624  */
1625 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1626                                 struct ext4_ext_path *path)
1627 {
1628         struct ext4_extent_header *eh;
1629         int depth = ext_depth(inode);
1630         struct ext4_extent *ex;
1631         __le32 border;
1632         int k, err = 0;
1633
1634         eh = path[depth].p_hdr;
1635         ex = path[depth].p_ext;
1636
1637         if (unlikely(ex == NULL || eh == NULL)) {
1638                 EXT4_ERROR_INODE(inode,
1639                                  "ex %p == NULL or eh %p == NULL", ex, eh);
1640                 return -EIO;
1641         }
1642
1643         if (depth == 0) {
1644                 /* there is no tree at all */
1645                 return 0;
1646         }
1647
1648         if (ex != EXT_FIRST_EXTENT(eh)) {
1649                 /* we correct tree if first leaf got modified only */
1650                 return 0;
1651         }
1652
1653         /*
1654          * TODO: we need correction if border is smaller than current one
1655          */
1656         k = depth - 1;
1657         border = path[depth].p_ext->ee_block;
1658         err = ext4_ext_get_access(handle, inode, path + k);
1659         if (err)
1660                 return err;
1661         path[k].p_idx->ei_block = border;
1662         err = ext4_ext_dirty(handle, inode, path + k);
1663         if (err)
1664                 return err;
1665
1666         while (k--) {
1667                 /* change all left-side indexes */
1668                 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1669                         break;
1670                 err = ext4_ext_get_access(handle, inode, path + k);
1671                 if (err)
1672                         break;
1673                 path[k].p_idx->ei_block = border;
1674                 err = ext4_ext_dirty(handle, inode, path + k);
1675                 if (err)
1676                         break;
1677         }
1678
1679         return err;
1680 }
1681
1682 int
1683 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1684                                 struct ext4_extent *ex2)
1685 {
1686         unsigned short ext1_ee_len, ext2_ee_len;
1687
1688         /*
1689          * Make sure that both extents are initialized. We don't merge
1690          * uninitialized extents so that we can be sure that end_io code has
1691          * the extent that was written properly split out and conversion to
1692          * initialized is trivial.
1693          */
1694         if (ext4_ext_is_uninitialized(ex1) || ext4_ext_is_uninitialized(ex2))
1695                 return 0;
1696
1697         ext1_ee_len = ext4_ext_get_actual_len(ex1);
1698         ext2_ee_len = ext4_ext_get_actual_len(ex2);
1699
1700         if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1701                         le32_to_cpu(ex2->ee_block))
1702                 return 0;
1703
1704         /*
1705          * To allow future support for preallocated extents to be added
1706          * as an RO_COMPAT feature, refuse to merge to extents if
1707          * this can result in the top bit of ee_len being set.
1708          */
1709         if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1710                 return 0;
1711 #ifdef AGGRESSIVE_TEST
1712         if (ext1_ee_len >= 4)
1713                 return 0;
1714 #endif
1715
1716         if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1717                 return 1;
1718         return 0;
1719 }
1720
1721 /*
1722  * This function tries to merge the "ex" extent to the next extent in the tree.
1723  * It always tries to merge towards right. If you want to merge towards
1724  * left, pass "ex - 1" as argument instead of "ex".
1725  * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1726  * 1 if they got merged.
1727  */
1728 static int ext4_ext_try_to_merge_right(struct inode *inode,
1729                                  struct ext4_ext_path *path,
1730                                  struct ext4_extent *ex)
1731 {
1732         struct ext4_extent_header *eh;
1733         unsigned int depth, len;
1734         int merge_done = 0;
1735
1736         depth = ext_depth(inode);
1737         BUG_ON(path[depth].p_hdr == NULL);
1738         eh = path[depth].p_hdr;
1739
1740         while (ex < EXT_LAST_EXTENT(eh)) {
1741                 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1742                         break;
1743                 /* merge with next extent! */
1744                 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1745                                 + ext4_ext_get_actual_len(ex + 1));
1746
1747                 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1748                         len = (EXT_LAST_EXTENT(eh) - ex - 1)
1749                                 * sizeof(struct ext4_extent);
1750                         memmove(ex + 1, ex + 2, len);
1751                 }
1752                 le16_add_cpu(&eh->eh_entries, -1);
1753                 merge_done = 1;
1754                 WARN_ON(eh->eh_entries == 0);
1755                 if (!eh->eh_entries)
1756                         EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1757         }
1758
1759         return merge_done;
1760 }
1761
1762 /*
1763  * This function does a very simple check to see if we can collapse
1764  * an extent tree with a single extent tree leaf block into the inode.
1765  */
1766 static void ext4_ext_try_to_merge_up(handle_t *handle,
1767                                      struct inode *inode,
1768                                      struct ext4_ext_path *path)
1769 {
1770         size_t s;
1771         unsigned max_root = ext4_ext_space_root(inode, 0);
1772         ext4_fsblk_t blk;
1773
1774         if ((path[0].p_depth != 1) ||
1775             (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1776             (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1777                 return;
1778
1779         /*
1780          * We need to modify the block allocation bitmap and the block
1781          * group descriptor to release the extent tree block.  If we
1782          * can't get the journal credits, give up.
1783          */
1784         if (ext4_journal_extend(handle, 2))
1785                 return;
1786
1787         /*
1788          * Copy the extent data up to the inode
1789          */
1790         blk = ext4_idx_pblock(path[0].p_idx);
1791         s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1792                 sizeof(struct ext4_extent_idx);
1793         s += sizeof(struct ext4_extent_header);
1794
1795         memcpy(path[0].p_hdr, path[1].p_hdr, s);
1796         path[0].p_depth = 0;
1797         path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1798                 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1799         path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1800
1801         brelse(path[1].p_bh);
1802         ext4_free_blocks(handle, inode, NULL, blk, 1,
1803                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET |
1804                          EXT4_FREE_BLOCKS_RESERVE);
1805 }
1806
1807 /*
1808  * This function tries to merge the @ex extent to neighbours in the tree.
1809  * return 1 if merge left else 0.
1810  */
1811 static void ext4_ext_try_to_merge(handle_t *handle,
1812                                   struct inode *inode,
1813                                   struct ext4_ext_path *path,
1814                                   struct ext4_extent *ex) {
1815         struct ext4_extent_header *eh;
1816         unsigned int depth;
1817         int merge_done = 0;
1818
1819         depth = ext_depth(inode);
1820         BUG_ON(path[depth].p_hdr == NULL);
1821         eh = path[depth].p_hdr;
1822
1823         if (ex > EXT_FIRST_EXTENT(eh))
1824                 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1825
1826         if (!merge_done)
1827                 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1828
1829         ext4_ext_try_to_merge_up(handle, inode, path);
1830 }
1831
1832 /*
1833  * check if a portion of the "newext" extent overlaps with an
1834  * existing extent.
1835  *
1836  * If there is an overlap discovered, it updates the length of the newext
1837  * such that there will be no overlap, and then returns 1.
1838  * If there is no overlap found, it returns 0.
1839  */
1840 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1841                                            struct inode *inode,
1842                                            struct ext4_extent *newext,
1843                                            struct ext4_ext_path *path)
1844 {
1845         ext4_lblk_t b1, b2;
1846         unsigned int depth, len1;
1847         unsigned int ret = 0;
1848
1849         b1 = le32_to_cpu(newext->ee_block);
1850         len1 = ext4_ext_get_actual_len(newext);
1851         depth = ext_depth(inode);
1852         if (!path[depth].p_ext)
1853                 goto out;
1854         b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1855         b2 &= ~(sbi->s_cluster_ratio - 1);
1856
1857         /*
1858          * get the next allocated block if the extent in the path
1859          * is before the requested block(s)
1860          */
1861         if (b2 < b1) {
1862                 b2 = ext4_ext_next_allocated_block(path);
1863                 if (b2 == EXT_MAX_BLOCKS)
1864                         goto out;
1865                 b2 &= ~(sbi->s_cluster_ratio - 1);
1866         }
1867
1868         /* check for wrap through zero on extent logical start block*/
1869         if (b1 + len1 < b1) {
1870                 len1 = EXT_MAX_BLOCKS - b1;
1871                 newext->ee_len = cpu_to_le16(len1);
1872                 ret = 1;
1873         }
1874
1875         /* check for overlap */
1876         if (b1 + len1 > b2) {
1877                 newext->ee_len = cpu_to_le16(b2 - b1);
1878                 ret = 1;
1879         }
1880 out:
1881         return ret;
1882 }
1883
1884 /*
1885  * ext4_ext_insert_extent:
1886  * tries to merge requsted extent into the existing extent or
1887  * inserts requested extent as new one into the tree,
1888  * creating new leaf in the no-space case.
1889  */
1890 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1891                                 struct ext4_ext_path *path,
1892                                 struct ext4_extent *newext, int gb_flags)
1893 {
1894         struct ext4_extent_header *eh;
1895         struct ext4_extent *ex, *fex;
1896         struct ext4_extent *nearex; /* nearest extent */
1897         struct ext4_ext_path *npath = NULL;
1898         int depth, len, err;
1899         ext4_lblk_t next;
1900         int mb_flags = 0;
1901
1902         if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1903                 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1904                 return -EIO;
1905         }
1906         depth = ext_depth(inode);
1907         ex = path[depth].p_ext;
1908         eh = path[depth].p_hdr;
1909         if (unlikely(path[depth].p_hdr == NULL)) {
1910                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1911                 return -EIO;
1912         }
1913
1914         /* try to insert block into found extent and return */
1915         if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1916
1917                 /*
1918                  * Try to see whether we should rather test the extent on
1919                  * right from ex, or from the left of ex. This is because
1920                  * ext4_ext_find_extent() can return either extent on the
1921                  * left, or on the right from the searched position. This
1922                  * will make merging more effective.
1923                  */
1924                 if (ex < EXT_LAST_EXTENT(eh) &&
1925                     (le32_to_cpu(ex->ee_block) +
1926                     ext4_ext_get_actual_len(ex) <
1927                     le32_to_cpu(newext->ee_block))) {
1928                         ex += 1;
1929                         goto prepend;
1930                 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1931                            (le32_to_cpu(newext->ee_block) +
1932                            ext4_ext_get_actual_len(newext) <
1933                            le32_to_cpu(ex->ee_block)))
1934                         ex -= 1;
1935
1936                 /* Try to append newex to the ex */
1937                 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1938                         ext_debug("append [%d]%d block to %u:[%d]%d"
1939                                   "(from %llu)\n",
1940                                   ext4_ext_is_uninitialized(newext),
1941                                   ext4_ext_get_actual_len(newext),
1942                                   le32_to_cpu(ex->ee_block),
1943                                   ext4_ext_is_uninitialized(ex),
1944                                   ext4_ext_get_actual_len(ex),
1945                                   ext4_ext_pblock(ex));
1946                         err = ext4_ext_get_access(handle, inode,
1947                                                   path + depth);
1948                         if (err)
1949                                 return err;
1950
1951                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1952                                         + ext4_ext_get_actual_len(newext));
1953                         eh = path[depth].p_hdr;
1954                         nearex = ex;
1955                         goto merge;
1956                 }
1957
1958 prepend:
1959                 /* Try to prepend newex to the ex */
1960                 if (ext4_can_extents_be_merged(inode, newext, ex)) {
1961                         ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
1962                                   "(from %llu)\n",
1963                                   le32_to_cpu(newext->ee_block),
1964                                   ext4_ext_is_uninitialized(newext),
1965                                   ext4_ext_get_actual_len(newext),
1966                                   le32_to_cpu(ex->ee_block),
1967                                   ext4_ext_is_uninitialized(ex),
1968                                   ext4_ext_get_actual_len(ex),
1969                                   ext4_ext_pblock(ex));
1970                         err = ext4_ext_get_access(handle, inode,
1971                                                   path + depth);
1972                         if (err)
1973                                 return err;
1974
1975                         ex->ee_block = newext->ee_block;
1976                         ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
1977                         ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1978                                         + ext4_ext_get_actual_len(newext));
1979                         eh = path[depth].p_hdr;
1980                         nearex = ex;
1981                         goto merge;
1982                 }
1983         }
1984
1985         depth = ext_depth(inode);
1986         eh = path[depth].p_hdr;
1987         if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1988                 goto has_space;
1989
1990         /* probably next leaf has space for us? */
1991         fex = EXT_LAST_EXTENT(eh);
1992         next = EXT_MAX_BLOCKS;
1993         if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1994                 next = ext4_ext_next_leaf_block(path);
1995         if (next != EXT_MAX_BLOCKS) {
1996                 ext_debug("next leaf block - %u\n", next);
1997                 BUG_ON(npath != NULL);
1998                 npath = ext4_ext_find_extent(inode, next, NULL, 0);
1999                 if (IS_ERR(npath))
2000                         return PTR_ERR(npath);
2001                 BUG_ON(npath->p_depth != path->p_depth);
2002                 eh = npath[depth].p_hdr;
2003                 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2004                         ext_debug("next leaf isn't full(%d)\n",
2005                                   le16_to_cpu(eh->eh_entries));
2006                         path = npath;
2007                         goto has_space;
2008                 }
2009                 ext_debug("next leaf has no free space(%d,%d)\n",
2010                           le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2011         }
2012
2013         /*
2014          * There is no free space in the found leaf.
2015          * We're gonna add a new leaf in the tree.
2016          */
2017         if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2018                 mb_flags = EXT4_MB_USE_RESERVED;
2019         err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2020                                        path, newext);
2021         if (err)
2022                 goto cleanup;
2023         depth = ext_depth(inode);
2024         eh = path[depth].p_hdr;
2025
2026 has_space:
2027         nearex = path[depth].p_ext;
2028
2029         err = ext4_ext_get_access(handle, inode, path + depth);
2030         if (err)
2031                 goto cleanup;
2032
2033         if (!nearex) {
2034                 /* there is no extent in this leaf, create first one */
2035                 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2036                                 le32_to_cpu(newext->ee_block),
2037                                 ext4_ext_pblock(newext),
2038                                 ext4_ext_is_uninitialized(newext),
2039                                 ext4_ext_get_actual_len(newext));
2040                 nearex = EXT_FIRST_EXTENT(eh);
2041         } else {
2042                 if (le32_to_cpu(newext->ee_block)
2043                            > le32_to_cpu(nearex->ee_block)) {
2044                         /* Insert after */
2045                         ext_debug("insert %u:%llu:[%d]%d before: "
2046                                         "nearest %p\n",
2047                                         le32_to_cpu(newext->ee_block),
2048                                         ext4_ext_pblock(newext),
2049                                         ext4_ext_is_uninitialized(newext),
2050                                         ext4_ext_get_actual_len(newext),
2051                                         nearex);
2052                         nearex++;
2053                 } else {
2054                         /* Insert before */
2055                         BUG_ON(newext->ee_block == nearex->ee_block);
2056                         ext_debug("insert %u:%llu:[%d]%d after: "
2057                                         "nearest %p\n",
2058                                         le32_to_cpu(newext->ee_block),
2059                                         ext4_ext_pblock(newext),
2060                                         ext4_ext_is_uninitialized(newext),
2061                                         ext4_ext_get_actual_len(newext),
2062                                         nearex);
2063                 }
2064                 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2065                 if (len > 0) {
2066                         ext_debug("insert %u:%llu:[%d]%d: "
2067                                         "move %d extents from 0x%p to 0x%p\n",
2068                                         le32_to_cpu(newext->ee_block),
2069                                         ext4_ext_pblock(newext),
2070                                         ext4_ext_is_uninitialized(newext),
2071                                         ext4_ext_get_actual_len(newext),
2072                                         len, nearex, nearex + 1);
2073                         memmove(nearex + 1, nearex,
2074                                 len * sizeof(struct ext4_extent));
2075                 }
2076         }
2077
2078         le16_add_cpu(&eh->eh_entries, 1);
2079         path[depth].p_ext = nearex;
2080         nearex->ee_block = newext->ee_block;
2081         ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2082         nearex->ee_len = newext->ee_len;
2083
2084 merge:
2085         /* try to merge extents */
2086         if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2087                 ext4_ext_try_to_merge(handle, inode, path, nearex);
2088
2089
2090         /* time to correct all indexes above */
2091         err = ext4_ext_correct_indexes(handle, inode, path);
2092         if (err)
2093                 goto cleanup;
2094
2095         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2096
2097 cleanup:
2098         if (npath) {
2099                 ext4_ext_drop_refs(npath);
2100                 kfree(npath);
2101         }
2102         return err;
2103 }
2104
2105 static int ext4_fill_fiemap_extents(struct inode *inode,
2106                                     ext4_lblk_t block, ext4_lblk_t num,
2107                                     struct fiemap_extent_info *fieinfo)
2108 {
2109         struct ext4_ext_path *path = NULL;
2110         struct ext4_extent *ex;
2111         struct extent_status es;
2112         ext4_lblk_t next, next_del, start = 0, end = 0;
2113         ext4_lblk_t last = block + num;
2114         int exists, depth = 0, err = 0;
2115         unsigned int flags = 0;
2116         unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2117
2118         while (block < last && block != EXT_MAX_BLOCKS) {
2119                 num = last - block;
2120                 /* find extent for this block */
2121                 down_read(&EXT4_I(inode)->i_data_sem);
2122
2123                 if (path && ext_depth(inode) != depth) {
2124                         /* depth was changed. we have to realloc path */
2125                         kfree(path);
2126                         path = NULL;
2127                 }
2128
2129                 path = ext4_ext_find_extent(inode, block, path, 0);
2130                 if (IS_ERR(path)) {
2131                         up_read(&EXT4_I(inode)->i_data_sem);
2132                         err = PTR_ERR(path);
2133                         path = NULL;
2134                         break;
2135                 }
2136
2137                 depth = ext_depth(inode);
2138                 if (unlikely(path[depth].p_hdr == NULL)) {
2139                         up_read(&EXT4_I(inode)->i_data_sem);
2140                         EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2141                         err = -EIO;
2142                         break;
2143                 }
2144                 ex = path[depth].p_ext;
2145                 next = ext4_ext_next_allocated_block(path);
2146                 ext4_ext_drop_refs(path);
2147
2148                 flags = 0;
2149                 exists = 0;
2150                 if (!ex) {
2151                         /* there is no extent yet, so try to allocate
2152                          * all requested space */
2153                         start = block;
2154                         end = block + num;
2155                 } else if (le32_to_cpu(ex->ee_block) > block) {
2156                         /* need to allocate space before found extent */
2157                         start = block;
2158                         end = le32_to_cpu(ex->ee_block);
2159                         if (block + num < end)
2160                                 end = block + num;
2161                 } else if (block >= le32_to_cpu(ex->ee_block)
2162                                         + ext4_ext_get_actual_len(ex)) {
2163                         /* need to allocate space after found extent */
2164                         start = block;
2165                         end = block + num;
2166                         if (end >= next)
2167                                 end = next;
2168                 } else if (block >= le32_to_cpu(ex->ee_block)) {
2169                         /*
2170                          * some part of requested space is covered
2171                          * by found extent
2172                          */
2173                         start = block;
2174                         end = le32_to_cpu(ex->ee_block)
2175                                 + ext4_ext_get_actual_len(ex);
2176                         if (block + num < end)
2177                                 end = block + num;
2178                         exists = 1;
2179                 } else {
2180                         BUG();
2181                 }
2182                 BUG_ON(end <= start);
2183
2184                 if (!exists) {
2185                         es.es_lblk = start;
2186                         es.es_len = end - start;
2187                         es.es_pblk = 0;
2188                 } else {
2189                         es.es_lblk = le32_to_cpu(ex->ee_block);
2190                         es.es_len = ext4_ext_get_actual_len(ex);
2191                         es.es_pblk = ext4_ext_pblock(ex);
2192                         if (ext4_ext_is_uninitialized(ex))
2193                                 flags |= FIEMAP_EXTENT_UNWRITTEN;
2194                 }
2195
2196                 /*
2197                  * Find delayed extent and update es accordingly. We call
2198                  * it even in !exists case to find out whether es is the
2199                  * last existing extent or not.
2200                  */
2201                 next_del = ext4_find_delayed_extent(inode, &es);
2202                 if (!exists && next_del) {
2203                         exists = 1;
2204                         flags |= (FIEMAP_EXTENT_DELALLOC |
2205                                   FIEMAP_EXTENT_UNKNOWN);
2206                 }
2207                 up_read(&EXT4_I(inode)->i_data_sem);
2208
2209                 if (unlikely(es.es_len == 0)) {
2210                         EXT4_ERROR_INODE(inode, "es.es_len == 0");
2211                         err = -EIO;
2212                         break;
2213                 }
2214
2215                 /*
2216                  * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2217                  * we need to check next == EXT_MAX_BLOCKS because it is
2218                  * possible that an extent is with unwritten and delayed
2219                  * status due to when an extent is delayed allocated and
2220                  * is allocated by fallocate status tree will track both of
2221                  * them in a extent.
2222                  *
2223                  * So we could return a unwritten and delayed extent, and
2224                  * its block is equal to 'next'.
2225                  */
2226                 if (next == next_del && next == EXT_MAX_BLOCKS) {
2227                         flags |= FIEMAP_EXTENT_LAST;
2228                         if (unlikely(next_del != EXT_MAX_BLOCKS ||
2229                                      next != EXT_MAX_BLOCKS)) {
2230                                 EXT4_ERROR_INODE(inode,
2231                                                  "next extent == %u, next "
2232                                                  "delalloc extent = %u",
2233                                                  next, next_del);
2234                                 err = -EIO;
2235                                 break;
2236                         }
2237                 }
2238
2239                 if (exists) {
2240                         err = fiemap_fill_next_extent(fieinfo,
2241                                 (__u64)es.es_lblk << blksize_bits,
2242                                 (__u64)es.es_pblk << blksize_bits,
2243                                 (__u64)es.es_len << blksize_bits,
2244                                 flags);
2245                         if (err < 0)
2246                                 break;
2247                         if (err == 1) {
2248                                 err = 0;
2249                                 break;
2250                         }
2251                 }
2252
2253                 block = es.es_lblk + es.es_len;
2254         }
2255
2256         if (path) {
2257                 ext4_ext_drop_refs(path);
2258                 kfree(path);
2259         }
2260
2261         return err;
2262 }
2263
2264 /*
2265  * ext4_ext_put_gap_in_cache:
2266  * calculate boundaries of the gap that the requested block fits into
2267  * and cache this gap
2268  */
2269 static void
2270 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2271                                 ext4_lblk_t block)
2272 {
2273         int depth = ext_depth(inode);
2274         unsigned long len = 0;
2275         ext4_lblk_t lblock = 0;
2276         struct ext4_extent *ex;
2277
2278         ex = path[depth].p_ext;
2279         if (ex == NULL) {
2280                 /*
2281                  * there is no extent yet, so gap is [0;-] and we
2282                  * don't cache it
2283                  */
2284                 ext_debug("cache gap(whole file):");
2285         } else if (block < le32_to_cpu(ex->ee_block)) {
2286                 lblock = block;
2287                 len = le32_to_cpu(ex->ee_block) - block;
2288                 ext_debug("cache gap(before): %u [%u:%u]",
2289                                 block,
2290                                 le32_to_cpu(ex->ee_block),
2291                                  ext4_ext_get_actual_len(ex));
2292                 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2293                         ext4_es_insert_extent(inode, lblock, len, ~0,
2294                                               EXTENT_STATUS_HOLE);
2295         } else if (block >= le32_to_cpu(ex->ee_block)
2296                         + ext4_ext_get_actual_len(ex)) {
2297                 ext4_lblk_t next;
2298                 lblock = le32_to_cpu(ex->ee_block)
2299                         + ext4_ext_get_actual_len(ex);
2300
2301                 next = ext4_ext_next_allocated_block(path);
2302                 ext_debug("cache gap(after): [%u:%u] %u",
2303                                 le32_to_cpu(ex->ee_block),
2304                                 ext4_ext_get_actual_len(ex),
2305                                 block);
2306                 BUG_ON(next == lblock);
2307                 len = next - lblock;
2308                 if (!ext4_find_delalloc_range(inode, lblock, lblock + len - 1))
2309                         ext4_es_insert_extent(inode, lblock, len, ~0,
2310                                               EXTENT_STATUS_HOLE);
2311         } else {
2312                 BUG();
2313         }
2314
2315         ext_debug(" -> %u:%lu\n", lblock, len);
2316 }
2317
2318 /*
2319  * ext4_ext_rm_idx:
2320  * removes index from the index block.
2321  */
2322 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2323                         struct ext4_ext_path *path, int depth)
2324 {
2325         int err;
2326         ext4_fsblk_t leaf;
2327
2328         /* free index block */
2329         depth--;
2330         path = path + depth;
2331         leaf = ext4_idx_pblock(path->p_idx);
2332         if (unlikely(path->p_hdr->eh_entries == 0)) {
2333                 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2334                 return -EIO;
2335         }
2336         err = ext4_ext_get_access(handle, inode, path);
2337         if (err)
2338                 return err;
2339
2340         if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2341                 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2342                 len *= sizeof(struct ext4_extent_idx);
2343                 memmove(path->p_idx, path->p_idx + 1, len);
2344         }
2345
2346         le16_add_cpu(&path->p_hdr->eh_entries, -1);
2347         err = ext4_ext_dirty(handle, inode, path);
2348         if (err)
2349                 return err;
2350         ext_debug("index is empty, remove it, free block %llu\n", leaf);
2351         trace_ext4_ext_rm_idx(inode, leaf);
2352
2353         ext4_free_blocks(handle, inode, NULL, leaf, 1,
2354                          EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2355
2356         while (--depth >= 0) {
2357                 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2358                         break;
2359                 path--;
2360                 err = ext4_ext_get_access(handle, inode, path);
2361                 if (err)
2362                         break;
2363                 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2364                 err = ext4_ext_dirty(handle, inode, path);
2365                 if (err)
2366                         break;
2367         }
2368         return err;
2369 }
2370
2371 /*
2372  * ext4_ext_calc_credits_for_single_extent:
2373  * This routine returns max. credits that needed to insert an extent
2374  * to the extent tree.
2375  * When pass the actual path, the caller should calculate credits
2376  * under i_data_sem.
2377  */
2378 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2379                                                 struct ext4_ext_path *path)
2380 {
2381         if (path) {
2382                 int depth = ext_depth(inode);
2383                 int ret = 0;
2384
2385                 /* probably there is space in leaf? */
2386                 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2387                                 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2388
2389                         /*
2390                          *  There are some space in the leaf tree, no
2391                          *  need to account for leaf block credit
2392                          *
2393                          *  bitmaps and block group descriptor blocks
2394                          *  and other metadata blocks still need to be
2395                          *  accounted.
2396                          */
2397                         /* 1 bitmap, 1 block group descriptor */
2398                         ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2399                         return ret;
2400                 }
2401         }
2402
2403         return ext4_chunk_trans_blocks(inode, nrblocks);
2404 }
2405
2406 /*
2407  * How many index/leaf blocks need to change/allocate to add @extents extents?
2408  *
2409  * If we add a single extent, then in the worse case, each tree level
2410  * index/leaf need to be changed in case of the tree split.
2411  *
2412  * If more extents are inserted, they could cause the whole tree split more
2413  * than once, but this is really rare.
2414  */
2415 int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2416 {
2417         int index;
2418         int depth;
2419
2420         /* If we are converting the inline data, only one is needed here. */
2421         if (ext4_has_inline_data(inode))
2422                 return 1;
2423
2424         depth = ext_depth(inode);
2425
2426         if (extents <= 1)
2427                 index = depth * 2;
2428         else
2429                 index = depth * 3;
2430
2431         return index;
2432 }
2433
2434 static inline int get_default_free_blocks_flags(struct inode *inode)
2435 {
2436         if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2437                 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2438         else if (ext4_should_journal_data(inode))
2439                 return EXT4_FREE_BLOCKS_FORGET;
2440         return 0;
2441 }
2442
2443 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2444                               struct ext4_extent *ex,
2445                               long long *partial_cluster,
2446                               ext4_lblk_t from, ext4_lblk_t to)
2447 {
2448         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2449         unsigned short ee_len =  ext4_ext_get_actual_len(ex);
2450         ext4_fsblk_t pblk;
2451         int flags = get_default_free_blocks_flags(inode);
2452
2453         /*
2454          * For bigalloc file systems, we never free a partial cluster
2455          * at the beginning of the extent.  Instead, we make a note
2456          * that we tried freeing the cluster, and check to see if we
2457          * need to free it on a subsequent call to ext4_remove_blocks,
2458          * or at the end of the ext4_truncate() operation.
2459          */
2460         flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2461
2462         trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2463         /*
2464          * If we have a partial cluster, and it's different from the
2465          * cluster of the last block, we need to explicitly free the
2466          * partial cluster here.
2467          */
2468         pblk = ext4_ext_pblock(ex) + ee_len - 1;
2469         if ((*partial_cluster > 0) &&
2470             (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2471                 ext4_free_blocks(handle, inode, NULL,
2472                                  EXT4_C2B(sbi, *partial_cluster),
2473                                  sbi->s_cluster_ratio, flags);
2474                 *partial_cluster = 0;
2475         }
2476
2477 #ifdef EXTENTS_STATS
2478         {
2479                 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2480                 spin_lock(&sbi->s_ext_stats_lock);
2481                 sbi->s_ext_blocks += ee_len;
2482                 sbi->s_ext_extents++;
2483                 if (ee_len < sbi->s_ext_min)
2484                         sbi->s_ext_min = ee_len;
2485                 if (ee_len > sbi->s_ext_max)
2486                         sbi->s_ext_max = ee_len;
2487                 if (ext_depth(inode) > sbi->s_depth_max)
2488                         sbi->s_depth_max = ext_depth(inode);
2489                 spin_unlock(&sbi->s_ext_stats_lock);
2490         }
2491 #endif
2492         if (from >= le32_to_cpu(ex->ee_block)
2493             && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2494                 /* tail removal */
2495                 ext4_lblk_t num;
2496                 unsigned int unaligned;
2497
2498                 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2499                 pblk = ext4_ext_pblock(ex) + ee_len - num;
2500                 /*
2501                  * Usually we want to free partial cluster at the end of the
2502                  * extent, except for the situation when the cluster is still
2503                  * used by any other extent (partial_cluster is negative).
2504                  */
2505                 if (*partial_cluster < 0 &&
2506                     -(*partial_cluster) == EXT4_B2C(sbi, pblk + num - 1))
2507                         flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2508
2509                 ext_debug("free last %u blocks starting %llu partial %lld\n",
2510                           num, pblk, *partial_cluster);
2511                 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2512                 /*
2513                  * If the block range to be freed didn't start at the
2514                  * beginning of a cluster, and we removed the entire
2515                  * extent and the cluster is not used by any other extent,
2516                  * save the partial cluster here, since we might need to
2517                  * delete if we determine that the truncate operation has
2518                  * removed all of the blocks in the cluster.
2519                  *
2520                  * On the other hand, if we did not manage to free the whole
2521                  * extent, we have to mark the cluster as used (store negative
2522                  * cluster number in partial_cluster).
2523                  */
2524                 unaligned = pblk & (sbi->s_cluster_ratio - 1);
2525                 if (unaligned && (ee_len == num) &&
2526                     (*partial_cluster != -((long long)EXT4_B2C(sbi, pblk))))
2527                         *partial_cluster = EXT4_B2C(sbi, pblk);
2528                 else if (unaligned)
2529                         *partial_cluster = -((long long)EXT4_B2C(sbi, pblk));
2530                 else if (*partial_cluster > 0)
2531                         *partial_cluster = 0;
2532         } else
2533                 ext4_error(sbi->s_sb, "strange request: removal(2) "
2534                            "%u-%u from %u:%u\n",
2535                            from, to, le32_to_cpu(ex->ee_block), ee_len);
2536         return 0;
2537 }
2538
2539
2540 /*
2541  * ext4_ext_rm_leaf() Removes the extents associated with the
2542  * blocks appearing between "start" and "end", and splits the extents
2543  * if "start" and "end" appear in the same extent
2544  *
2545  * @handle: The journal handle
2546  * @inode:  The files inode
2547  * @path:   The path to the leaf
2548  * @partial_cluster: The cluster which we'll have to free if all extents
2549  *                   has been released from it. It gets negative in case
2550  *                   that the cluster is still used.
2551  * @start:  The first block to remove
2552  * @end:   The last block to remove
2553  */
2554 static int
2555 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2556                  struct ext4_ext_path *path,
2557                  long long *partial_cluster,
2558                  ext4_lblk_t start, ext4_lblk_t end)
2559 {
2560         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2561         int err = 0, correct_index = 0;
2562         int depth = ext_depth(inode), credits;
2563         struct ext4_extent_header *eh;
2564         ext4_lblk_t a, b;
2565         unsigned num;
2566         ext4_lblk_t ex_ee_block;
2567         unsigned short ex_ee_len;
2568         unsigned uninitialized = 0;
2569         struct ext4_extent *ex;
2570         ext4_fsblk_t pblk;
2571
2572         /* the header must be checked already in ext4_ext_remove_space() */
2573         ext_debug("truncate since %u in leaf to %u\n", start, end);
2574         if (!path[depth].p_hdr)
2575                 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2576         eh = path[depth].p_hdr;
2577         if (unlikely(path[depth].p_hdr == NULL)) {
2578                 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2579                 return -EIO;
2580         }
2581         /* find where to start removing */
2582         ex = path[depth].p_ext;
2583         if (!ex)
2584                 ex = EXT_LAST_EXTENT(eh);
2585
2586         ex_ee_block = le32_to_cpu(ex->ee_block);
2587         ex_ee_len = ext4_ext_get_actual_len(ex);
2588
2589         trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2590
2591         while (ex >= EXT_FIRST_EXTENT(eh) &&
2592                         ex_ee_block + ex_ee_len > start) {
2593
2594                 if (ext4_ext_is_uninitialized(ex))
2595                         uninitialized = 1;
2596                 else
2597                         uninitialized = 0;
2598
2599                 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2600                          uninitialized, ex_ee_len);
2601                 path[depth].p_ext = ex;
2602
2603                 a = ex_ee_block > start ? ex_ee_block : start;
2604                 b = ex_ee_block+ex_ee_len - 1 < end ?
2605                         ex_ee_block+ex_ee_len - 1 : end;
2606
2607                 ext_debug("  border %u:%u\n", a, b);
2608
2609                 /* If this extent is beyond the end of the hole, skip it */
2610                 if (end < ex_ee_block) {
2611                         /*
2612                          * We're going to skip this extent and move to another,
2613                          * so if this extent is not cluster aligned we have
2614                          * to mark the current cluster as used to avoid
2615                          * accidentally freeing it later on
2616                          */
2617                         pblk = ext4_ext_pblock(ex);
2618                         if (pblk & (sbi->s_cluster_ratio - 1))
2619                                 *partial_cluster =
2620                                         -((long long)EXT4_B2C(sbi, pblk));
2621                         ex--;
2622                         ex_ee_block = le32_to_cpu(ex->ee_block);
2623                         ex_ee_len = ext4_ext_get_actual_len(ex);
2624                         continue;
2625                 } else if (b != ex_ee_block + ex_ee_len - 1) {
2626                         EXT4_ERROR_INODE(inode,
2627                                          "can not handle truncate %u:%u "
2628                                          "on extent %u:%u",
2629                                          start, end, ex_ee_block,
2630                                          ex_ee_block + ex_ee_len - 1);
2631                         err = -EIO;
2632                         goto out;
2633                 } else if (a != ex_ee_block) {
2634                         /* remove tail of the extent */
2635                         num = a - ex_ee_block;
2636                 } else {
2637                         /* remove whole extent: excellent! */
2638                         num = 0;
2639                 }
2640                 /*
2641                  * 3 for leaf, sb, and inode plus 2 (bmap and group
2642                  * descriptor) for each block group; assume two block
2643                  * groups plus ex_ee_len/blocks_per_block_group for
2644                  * the worst case
2645                  */
2646                 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2647                 if (ex == EXT_FIRST_EXTENT(eh)) {
2648                         correct_index = 1;
2649                         credits += (ext_depth(inode)) + 1;
2650                 }
2651                 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2652
2653                 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2654                 if (err)
2655                         goto out;
2656
2657                 err = ext4_ext_get_access(handle, inode, path + depth);
2658                 if (err)
2659                         goto out;
2660
2661                 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2662                                          a, b);
2663                 if (err)
2664                         goto out;
2665
2666                 if (num == 0)
2667                         /* this extent is removed; mark slot entirely unused */
2668                         ext4_ext_store_pblock(ex, 0);
2669
2670                 ex->ee_len = cpu_to_le16(num);
2671                 /*
2672                  * Do not mark uninitialized if all the blocks in the
2673                  * extent have been removed.
2674                  */
2675                 if (uninitialized && num)
2676                         ext4_ext_mark_uninitialized(ex);
2677                 /*
2678                  * If the extent was completely released,
2679                  * we need to remove it from the leaf
2680                  */
2681                 if (num == 0) {
2682                         if (end != EXT_MAX_BLOCKS - 1) {
2683                                 /*
2684                                  * For hole punching, we need to scoot all the
2685                                  * extents up when an extent is removed so that
2686                                  * we dont have blank extents in the middle
2687                                  */
2688                                 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2689                                         sizeof(struct ext4_extent));
2690
2691                                 /* Now get rid of the one at the end */
2692                                 memset(EXT_LAST_EXTENT(eh), 0,
2693                                         sizeof(struct ext4_extent));
2694                         }
2695                         le16_add_cpu(&eh->eh_entries, -1);
2696                 } else if (*partial_cluster > 0)
2697                         *partial_cluster = 0;
2698
2699                 err = ext4_ext_dirty(handle, inode, path + depth);
2700                 if (err)
2701                         goto out;
2702
2703                 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2704                                 ext4_ext_pblock(ex));
2705                 ex--;
2706                 ex_ee_block = le32_to_cpu(ex->ee_block);
2707                 ex_ee_len = ext4_ext_get_actual_len(ex);
2708         }
2709
2710         if (correct_index && eh->eh_entries)
2711                 err = ext4_ext_correct_indexes(handle, inode, path);
2712
2713         /*
2714          * Free the partial cluster only if the current extent does not
2715          * reference it. Otherwise we might free used cluster.
2716          */
2717         if (*partial_cluster > 0 &&
2718             (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2719              *partial_cluster)) {
2720                 int flags = get_default_free_blocks_flags(inode);
2721
2722                 ext4_free_blocks(handle, inode, NULL,
2723                                  EXT4_C2B(sbi, *partial_cluster),
2724                                  sbi->s_cluster_ratio, flags);
2725                 *partial_cluster = 0;
2726         }
2727
2728         /* if this leaf is free, then we should
2729          * remove it from index block above */
2730         if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2731                 err = ext4_ext_rm_idx(handle, inode, path, depth);
2732
2733 out:
2734         return err;
2735 }
2736
2737 /*
2738  * ext4_ext_more_to_rm:
2739  * returns 1 if current index has to be freed (even partial)
2740  */
2741 static int
2742 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2743 {
2744         BUG_ON(path->p_idx == NULL);
2745
2746         if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2747                 return 0;
2748
2749         /*
2750          * if truncate on deeper level happened, it wasn't partial,
2751          * so we have to consider current index for truncation
2752          */
2753         if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2754                 return 0;
2755         return 1;
2756 }
2757
2758 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2759                           ext4_lblk_t end)
2760 {
2761         struct super_block *sb = inode->i_sb;
2762         int depth = ext_depth(inode);
2763         struct ext4_ext_path *path = NULL;
2764         long long partial_cluster = 0;
2765         handle_t *handle;
2766         int i = 0, err = 0;
2767
2768         ext_debug("truncate since %u to %u\n", start, end);
2769
2770         /* probably first extent we're gonna free will be last in block */
2771         handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2772         if (IS_ERR(handle))
2773                 return PTR_ERR(handle);
2774
2775 again:
2776         trace_ext4_ext_remove_space(inode, start, end, depth);
2777
2778         /*
2779          * Check if we are removing extents inside the extent tree. If that
2780          * is the case, we are going to punch a hole inside the extent tree
2781          * so we have to check whether we need to split the extent covering
2782          * the last block to remove so we can easily remove the part of it
2783          * in ext4_ext_rm_leaf().
2784          */
2785         if (end < EXT_MAX_BLOCKS - 1) {
2786                 struct ext4_extent *ex;
2787                 ext4_lblk_t ee_block;
2788
2789                 /* find extent for this block */
2790                 path = ext4_ext_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2791                 if (IS_ERR(path)) {
2792                         ext4_journal_stop(handle);
2793                         return PTR_ERR(path);
2794                 }
2795                 depth = ext_depth(inode);
2796                 /* Leaf not may not exist only if inode has no blocks at all */
2797                 ex = path[depth].p_ext;
2798                 if (!ex) {
2799                         if (depth) {
2800                                 EXT4_ERROR_INODE(inode,
2801                                                  "path[%d].p_hdr == NULL",
2802                                                  depth);
2803                                 err = -EIO;
2804                         }
2805                         goto out;
2806                 }
2807
2808                 ee_block = le32_to_cpu(ex->ee_block);
2809
2810                 /*
2811                  * See if the last block is inside the extent, if so split
2812                  * the extent at 'end' block so we can easily remove the
2813                  * tail of the first part of the split extent in
2814                  * ext4_ext_rm_leaf().
2815                  */
2816                 if (end >= ee_block &&
2817                     end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2818                         int split_flag = 0;
2819
2820                         if (ext4_ext_is_uninitialized(ex))
2821                                 split_flag = EXT4_EXT_MARK_UNINIT1 |
2822                                              EXT4_EXT_MARK_UNINIT2;
2823
2824                         /*
2825                          * Split the extent in two so that 'end' is the last
2826                          * block in the first new extent. Also we should not
2827                          * fail removing space due to ENOSPC so try to use
2828                          * reserved block if that happens.
2829                          */
2830                         err = ext4_split_extent_at(handle, inode, path,
2831                                         end + 1, split_flag,
2832                                         EXT4_EX_NOCACHE |
2833                                         EXT4_GET_BLOCKS_PRE_IO |
2834                                         EXT4_GET_BLOCKS_METADATA_NOFAIL);
2835
2836                         if (err < 0)
2837                                 goto out;
2838                 }
2839         }
2840         /*
2841          * We start scanning from right side, freeing all the blocks
2842          * after i_size and walking into the tree depth-wise.
2843          */
2844         depth = ext_depth(inode);
2845         if (path) {
2846                 int k = i = depth;
2847                 while (--k > 0)
2848                         path[k].p_block =
2849                                 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2850         } else {
2851                 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2852                                GFP_NOFS);
2853                 if (path == NULL) {
2854                         ext4_journal_stop(handle);
2855                         return -ENOMEM;
2856                 }
2857                 path[0].p_depth = depth;
2858                 path[0].p_hdr = ext_inode_hdr(inode);
2859                 i = 0;
2860
2861                 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2862                         err = -EIO;
2863                         goto out;
2864                 }
2865         }
2866         err = 0;
2867
2868         while (i >= 0 && err == 0) {
2869                 if (i == depth) {
2870                         /* this is leaf block */
2871                         err = ext4_ext_rm_leaf(handle, inode, path,
2872                                                &partial_cluster, start,
2873                                                end);
2874                         /* root level has p_bh == NULL, brelse() eats this */
2875                         brelse(path[i].p_bh);
2876                         path[i].p_bh = NULL;
2877                         i--;
2878                         continue;
2879                 }
2880
2881                 /* this is index block */
2882                 if (!path[i].p_hdr) {
2883                         ext_debug("initialize header\n");
2884                         path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2885                 }
2886
2887                 if (!path[i].p_idx) {
2888                         /* this level hasn't been touched yet */
2889                         path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2890                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2891                         ext_debug("init index ptr: hdr 0x%p, num %d\n",
2892                                   path[i].p_hdr,
2893                                   le16_to_cpu(path[i].p_hdr->eh_entries));
2894                 } else {
2895                         /* we were already here, see at next index */
2896                         path[i].p_idx--;
2897                 }
2898
2899                 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2900                                 i, EXT_FIRST_INDEX(path[i].p_hdr),
2901                                 path[i].p_idx);
2902                 if (ext4_ext_more_to_rm(path + i)) {
2903                         struct buffer_head *bh;
2904                         /* go to the next level */
2905                         ext_debug("move to level %d (block %llu)\n",
2906                                   i + 1, ext4_idx_pblock(path[i].p_idx));
2907                         memset(path + i + 1, 0, sizeof(*path));
2908                         bh = read_extent_tree_block(inode,
2909                                 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2910                                 EXT4_EX_NOCACHE);
2911                         if (IS_ERR(bh)) {
2912                                 /* should we reset i_size? */
2913                                 err = PTR_ERR(bh);
2914                                 break;
2915                         }
2916                         /* Yield here to deal with large extent trees.
2917                          * Should be a no-op if we did IO above. */
2918                         cond_resched();
2919                         if (WARN_ON(i + 1 > depth)) {
2920                                 err = -EIO;
2921                                 break;
2922                         }
2923                         path[i + 1].p_bh = bh;
2924
2925                         /* save actual number of indexes since this
2926                          * number is changed at the next iteration */
2927                         path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2928                         i++;
2929                 } else {
2930                         /* we finished processing this index, go up */
2931                         if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2932                                 /* index is empty, remove it;
2933                                  * handle must be already prepared by the
2934                                  * truncatei_leaf() */
2935                                 err = ext4_ext_rm_idx(handle, inode, path, i);
2936                         }
2937                         /* root level has p_bh == NULL, brelse() eats this */
2938                         brelse(path[i].p_bh);
2939                         path[i].p_bh = NULL;
2940                         i--;
2941                         ext_debug("return to level %d\n", i);
2942                 }
2943         }
2944
2945         trace_ext4_ext_remove_space_done(inode, start, end, depth,
2946                         partial_cluster, path->p_hdr->eh_entries);
2947
2948         /* If we still have something in the partial cluster and we have removed
2949          * even the first extent, then we should free the blocks in the partial
2950          * cluster as well. */
2951         if (partial_cluster > 0 && path->p_hdr->eh_entries == 0) {
2952                 int flags = get_default_free_blocks_flags(inode);
2953
2954                 ext4_free_blocks(handle, inode, NULL,
2955                                  EXT4_C2B(EXT4_SB(sb), partial_cluster),
2956                                  EXT4_SB(sb)->s_cluster_ratio, flags);
2957                 partial_cluster = 0;
2958         }
2959
2960         /* TODO: flexible tree reduction should be here */
2961         if (path->p_hdr->eh_entries == 0) {
2962                 /*
2963                  * truncate to zero freed all the tree,
2964                  * so we need to correct eh_depth
2965                  */
2966                 err = ext4_ext_get_access(handle, inode, path);
2967                 if (err == 0) {
2968                         ext_inode_hdr(inode)->eh_depth = 0;
2969                         ext_inode_hdr(inode)->eh_max =
2970                                 cpu_to_le16(ext4_ext_space_root(inode, 0));
2971                         err = ext4_ext_dirty(handle, inode, path);
2972                 }
2973         }
2974 out:
2975         ext4_ext_drop_refs(path);
2976         kfree(path);
2977         if (err == -EAGAIN) {
2978                 path = NULL;
2979                 goto again;
2980         }
2981         ext4_journal_stop(handle);
2982
2983         return err;
2984 }
2985
2986 /*
2987  * called at mount time
2988  */
2989 void ext4_ext_init(struct super_block *sb)
2990 {
2991         /*
2992          * possible initialization would be here
2993          */
2994
2995         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2996 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2997                 printk(KERN_INFO "EXT4-fs: file extents enabled"
2998 #ifdef AGGRESSIVE_TEST
2999                        ", aggressive tests"
3000 #endif
3001 #ifdef CHECK_BINSEARCH
3002                        ", check binsearch"
3003 #endif
3004 #ifdef EXTENTS_STATS
3005                        ", stats"
3006 #endif
3007                        "\n");
3008 #endif
3009 #ifdef EXTENTS_STATS
3010                 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3011                 EXT4_SB(sb)->s_ext_min = 1 << 30;
3012                 EXT4_SB(sb)->s_ext_max = 0;
3013 #endif
3014         }
3015 }
3016
3017 /*
3018  * called at umount time
3019  */
3020 void ext4_ext_release(struct super_block *sb)
3021 {
3022         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3023                 return;
3024
3025 #ifdef EXTENTS_STATS
3026         if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3027                 struct ext4_sb_info *sbi = EXT4_SB(sb);
3028                 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3029                         sbi->s_ext_blocks, sbi->s_ext_extents,
3030                         sbi->s_ext_blocks / sbi->s_ext_extents);
3031                 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3032                         sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3033         }
3034 #endif
3035 }
3036
3037 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3038 {
3039         ext4_lblk_t  ee_block;
3040         ext4_fsblk_t ee_pblock;
3041         unsigned int ee_len;
3042
3043         ee_block  = le32_to_cpu(ex->ee_block);
3044         ee_len    = ext4_ext_get_actual_len(ex);
3045         ee_pblock = ext4_ext_pblock(ex);
3046
3047         if (ee_len == 0)
3048                 return 0;
3049
3050         return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3051                                      EXTENT_STATUS_WRITTEN);
3052 }
3053
3054 /* FIXME!! we need to try to merge to left or right after zero-out  */
3055 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3056 {
3057         ext4_fsblk_t ee_pblock;
3058         unsigned int ee_len;
3059         int ret;
3060
3061         ee_len    = ext4_ext_get_actual_len(ex);
3062         ee_pblock = ext4_ext_pblock(ex);
3063
3064         ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
3065         if (ret > 0)
3066                 ret = 0;
3067
3068         return ret;
3069 }
3070
3071 /*
3072  * ext4_split_extent_at() splits an extent at given block.
3073  *
3074  * @handle: the journal handle
3075  * @inode: the file inode
3076  * @path: the path to the extent
3077  * @split: the logical block where the extent is splitted.
3078  * @split_flags: indicates if the extent could be zeroout if split fails, and
3079  *               the states(init or uninit) of new extents.
3080  * @flags: flags used to insert new extent to extent tree.
3081  *
3082  *
3083  * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3084  * of which are deterimined by split_flag.
3085  *
3086  * There are two cases:
3087  *  a> the extent are splitted into two extent.
3088  *  b> split is not needed, and just mark the extent.
3089  *
3090  * return 0 on success.
3091  */
3092 static int ext4_split_extent_at(handle_t *handle,
3093                              struct inode *inode,
3094                              struct ext4_ext_path *path,
3095                              ext4_lblk_t split,
3096                              int split_flag,
3097                              int flags)
3098 {
3099         ext4_fsblk_t newblock;
3100         ext4_lblk_t ee_block;
3101         struct ext4_extent *ex, newex, orig_ex, zero_ex;
3102         struct ext4_extent *ex2 = NULL;
3103         unsigned int ee_len, depth;
3104         int err = 0;
3105
3106         BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3107                (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3108
3109         ext_debug("ext4_split_extents_at: inode %lu, logical"
3110                 "block %llu\n", inode->i_ino, (unsigned long long)split);
3111
3112         ext4_ext_show_leaf(inode, path);
3113
3114         depth = ext_depth(inode);
3115         ex = path[depth].p_ext;
3116         ee_block = le32_to_cpu(ex->ee_block);
3117         ee_len = ext4_ext_get_actual_len(ex);
3118         newblock = split - ee_block + ext4_ext_pblock(ex);
3119
3120         BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3121         BUG_ON(!ext4_ext_is_uninitialized(ex) &&
3122                split_flag & (EXT4_EXT_MAY_ZEROOUT |
3123                              EXT4_EXT_MARK_UNINIT1 |
3124                              EXT4_EXT_MARK_UNINIT2));
3125
3126         err = ext4_ext_get_access(handle, inode, path + depth);
3127         if (err)
3128                 goto out;
3129
3130         if (split == ee_block) {
3131                 /*
3132                  * case b: block @split is the block that the extent begins with
3133                  * then we just change the state of the extent, and splitting
3134                  * is not needed.
3135                  */
3136                 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3137                         ext4_ext_mark_uninitialized(ex);
3138                 else
3139                         ext4_ext_mark_initialized(ex);
3140
3141                 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3142                         ext4_ext_try_to_merge(handle, inode, path, ex);
3143
3144                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3145                 goto out;
3146         }
3147
3148         /* case a */
3149         memcpy(&orig_ex, ex, sizeof(orig_ex));
3150         ex->ee_len = cpu_to_le16(split - ee_block);
3151         if (split_flag & EXT4_EXT_MARK_UNINIT1)
3152                 ext4_ext_mark_uninitialized(ex);
3153
3154         /*
3155          * path may lead to new leaf, not to original leaf any more
3156          * after ext4_ext_insert_extent() returns,
3157          */
3158         err = ext4_ext_dirty(handle, inode, path + depth);
3159         if (err)
3160                 goto fix_extent_len;
3161
3162         ex2 = &newex;
3163         ex2->ee_block = cpu_to_le32(split);
3164         ex2->ee_len   = cpu_to_le16(ee_len - (split - ee_block));
3165         ext4_ext_store_pblock(ex2, newblock);
3166         if (split_flag & EXT4_EXT_MARK_UNINIT2)
3167                 ext4_ext_mark_uninitialized(ex2);
3168
3169         err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
3170         if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3171                 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3172                         if (split_flag & EXT4_EXT_DATA_VALID1) {
3173                                 err = ext4_ext_zeroout(inode, ex2);
3174                                 zero_ex.ee_block = ex2->ee_block;
3175                                 zero_ex.ee_len = cpu_to_le16(
3176                                                 ext4_ext_get_actual_len(ex2));
3177                                 ext4_ext_store_pblock(&zero_ex,
3178                                                       ext4_ext_pblock(ex2));
3179                         } else {
3180                                 err = ext4_ext_zeroout(inode, ex);
3181                                 zero_ex.ee_block = ex->ee_block;
3182                                 zero_ex.ee_len = cpu_to_le16(
3183                                                 ext4_ext_get_actual_len(ex));
3184                                 ext4_ext_store_pblock(&zero_ex,
3185                                                       ext4_ext_pblock(ex));
3186                         }
3187                 } else {
3188                         err = ext4_ext_zeroout(inode, &orig_ex);
3189                         zero_ex.ee_block = orig_ex.ee_block;
3190                         zero_ex.ee_len = cpu_to_le16(
3191                                                 ext4_ext_get_actual_len(&orig_ex));
3192                         ext4_ext_store_pblock(&zero_ex,
3193                                               ext4_ext_pblock(&orig_ex));
3194                 }
3195
3196                 if (err)
3197                         goto fix_extent_len;
3198                 /* update the extent length and mark as initialized */
3199                 ex->ee_len = cpu_to_le16(ee_len);
3200                 ext4_ext_try_to_merge(handle, inode, path, ex);
3201                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3202                 if (err)
3203                         goto fix_extent_len;
3204
3205                 /* update extent status tree */
3206                 err = ext4_zeroout_es(inode, &zero_ex);
3207
3208                 goto out;
3209         } else if (err)
3210                 goto fix_extent_len;
3211
3212 out:
3213         ext4_ext_show_leaf(inode, path);
3214         return err;
3215
3216 fix_extent_len:
3217         ex->ee_len = orig_ex.ee_len;
3218         ext4_ext_dirty(handle, inode, path + depth);
3219         return err;
3220 }
3221
3222 /*
3223  * ext4_split_extents() splits an extent and mark extent which is covered
3224  * by @map as split_flags indicates
3225  *
3226  * It may result in splitting the extent into multiple extents (up to three)
3227  * There are three possibilities:
3228  *   a> There is no split required
3229  *   b> Splits in two extents: Split is happening at either end of the extent
3230  *   c> Splits in three extents: Somone is splitting in middle of the extent
3231  *
3232  */
3233 static int ext4_split_extent(handle_t *handle,
3234                               struct inode *inode,
3235                               struct ext4_ext_path *path,
3236                               struct ext4_map_blocks *map,
3237                               int split_flag,
3238                               int flags)
3239 {
3240         ext4_lblk_t ee_block;
3241         struct ext4_extent *ex;
3242         unsigned int ee_len, depth;
3243         int err = 0;
3244         int uninitialized;
3245         int split_flag1, flags1;
3246         int allocated = map->m_len;
3247
3248         depth = ext_depth(inode);
3249         ex = path[depth].p_ext;
3250         ee_block = le32_to_cpu(ex->ee_block);
3251         ee_len = ext4_ext_get_actual_len(ex);
3252         uninitialized = ext4_ext_is_uninitialized(ex);
3253
3254         if (map->m_lblk + map->m_len < ee_block + ee_len) {
3255                 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3256                 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3257                 if (uninitialized)
3258                         split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3259                                        EXT4_EXT_MARK_UNINIT2;
3260                 if (split_flag & EXT4_EXT_DATA_VALID2)
3261                         split_flag1 |= EXT4_EXT_DATA_VALID1;
3262                 err = ext4_split_extent_at(handle, inode, path,
3263                                 map->m_lblk + map->m_len, split_flag1, flags1);
3264                 if (err)
3265                         goto out;
3266         } else {
3267                 allocated = ee_len - (map->m_lblk - ee_block);
3268         }
3269         /*
3270          * Update path is required because previous ext4_split_extent_at() may
3271          * result in split of original leaf or extent zeroout.
3272          */
3273         ext4_ext_drop_refs(path);
3274         path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
3275         if (IS_ERR(path))
3276                 return PTR_ERR(path);
3277         depth = ext_depth(inode);
3278         ex = path[depth].p_ext;
3279         uninitialized = ext4_ext_is_uninitialized(ex);
3280         split_flag1 = 0;
3281
3282         if (map->m_lblk >= ee_block) {
3283                 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3284                 if (uninitialized) {
3285                         split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3286                         split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3287                                                      EXT4_EXT_MARK_UNINIT2);
3288                 }
3289                 err = ext4_split_extent_at(handle, inode, path,
3290                                 map->m_lblk, split_flag1, flags);
3291                 if (err)
3292                         goto out;
3293         }
3294
3295         ext4_ext_show_leaf(inode, path);
3296 out:
3297         return err ? err : allocated;
3298 }
3299
3300 /*
3301  * This function is called by ext4_ext_map_blocks() if someone tries to write
3302  * to an uninitialized extent. It may result in splitting the uninitialized
3303  * extent into multiple extents (up to three - one initialized and two
3304  * uninitialized).
3305  * There are three possibilities:
3306  *   a> There is no split required: Entire extent should be initialized
3307  *   b> Splits in two extents: Write is happening at either end of the extent
3308  *   c> Splits in three extents: Somone is writing in middle of the extent
3309  *
3310  * Pre-conditions:
3311  *  - The extent pointed to by 'path' is uninitialized.
3312  *  - The extent pointed to by 'path' contains a superset
3313  *    of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3314  *
3315  * Post-conditions on success:
3316  *  - the returned value is the number of blocks beyond map->l_lblk
3317  *    that are allocated and initialized.
3318  *    It is guaranteed to be >= map->m_len.
3319  */
3320 static int ext4_ext_convert_to_initialized(handle_t *handle,
3321                                            struct inode *inode,
3322                                            struct ext4_map_blocks *map,
3323                                            struct ext4_ext_path *path,
3324                                            int flags)
3325 {
3326         struct ext4_sb_info *sbi;
3327         struct ext4_extent_header *eh;
3328         struct ext4_map_blocks split_map;
3329         struct ext4_extent zero_ex;
3330         struct ext4_extent *ex, *abut_ex;
3331         ext4_lblk_t ee_block, eof_block;
3332         unsigned int ee_len, depth, map_len = map->m_len;
3333         int allocated = 0, max_zeroout = 0;
3334         int err = 0;
3335         int split_flag = 0;
3336
3337         ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3338                 "block %llu, max_blocks %u\n", inode->i_ino,
3339                 (unsigned long long)map->m_lblk, map_len);
3340
3341         sbi = EXT4_SB(inode->i_sb);
3342         eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3343                 inode->i_sb->s_blocksize_bits;
3344         if (eof_block < map->m_lblk + map_len)
3345                 eof_block = map->m_lblk + map_len;
3346
3347         depth = ext_depth(inode);
3348         eh = path[depth].p_hdr;
3349         ex = path[depth].p_ext;
3350         ee_block = le32_to_cpu(ex->ee_block);
3351         ee_len = ext4_ext_get_actual_len(ex);
3352         zero_ex.ee_len = 0;
3353
3354         trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3355
3356         /* Pre-conditions */
3357         BUG_ON(!ext4_ext_is_uninitialized(ex));
3358         BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3359
3360         /*
3361          * Attempt to transfer newly initialized blocks from the currently
3362          * uninitialized extent to its neighbor. This is much cheaper
3363          * than an insertion followed by a merge as those involve costly
3364          * memmove() calls. Transferring to the left is the common case in
3365          * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3366          * followed by append writes.
3367          *
3368          * Limitations of the current logic:
3369          *  - L1: we do not deal with writes covering the whole extent.
3370          *    This would require removing the extent if the transfer
3371          *    is possible.
3372          *  - L2: we only attempt to merge with an extent stored in the
3373          *    same extent tree node.
3374          */
3375         if ((map->m_lblk == ee_block) &&
3376                 /* See if we can merge left */
3377                 (map_len < ee_len) &&           /*L1*/
3378                 (ex > EXT_FIRST_EXTENT(eh))) {  /*L2*/
3379                 ext4_lblk_t prev_lblk;
3380                 ext4_fsblk_t prev_pblk, ee_pblk;
3381                 unsigned int prev_len;
3382
3383                 abut_ex = ex - 1;
3384                 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3385                 prev_len = ext4_ext_get_actual_len(abut_ex);
3386                 prev_pblk = ext4_ext_pblock(abut_ex);
3387                 ee_pblk = ext4_ext_pblock(ex);
3388
3389                 /*
3390                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3391                  * upon those conditions:
3392                  * - C1: abut_ex is initialized,
3393                  * - C2: abut_ex is logically abutting ex,
3394                  * - C3: abut_ex is physically abutting ex,
3395                  * - C4: abut_ex can receive the additional blocks without
3396                  *   overflowing the (initialized) length limit.
3397                  */
3398                 if ((!ext4_ext_is_uninitialized(abut_ex)) &&            /*C1*/
3399                         ((prev_lblk + prev_len) == ee_block) &&         /*C2*/
3400                         ((prev_pblk + prev_len) == ee_pblk) &&          /*C3*/
3401                         (prev_len < (EXT_INIT_MAX_LEN - map_len))) {    /*C4*/
3402                         err = ext4_ext_get_access(handle, inode, path + depth);
3403                         if (err)
3404                                 goto out;
3405
3406                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3407                                 map, ex, abut_ex);
3408
3409                         /* Shift the start of ex by 'map_len' blocks */
3410                         ex->ee_block = cpu_to_le32(ee_block + map_len);
3411                         ext4_ext_store_pblock(ex, ee_pblk + map_len);
3412                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3413                         ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3414
3415                         /* Extend abut_ex by 'map_len' blocks */
3416                         abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3417
3418                         /* Result: number of initialized blocks past m_lblk */
3419                         allocated = map_len;
3420                 }
3421         } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3422                    (map_len < ee_len) &&        /*L1*/
3423                    ex < EXT_LAST_EXTENT(eh)) {  /*L2*/
3424                 /* See if we can merge right */
3425                 ext4_lblk_t next_lblk;
3426                 ext4_fsblk_t next_pblk, ee_pblk;
3427                 unsigned int next_len;
3428
3429                 abut_ex = ex + 1;
3430                 next_lblk = le32_to_cpu(abut_ex->ee_block);
3431                 next_len = ext4_ext_get_actual_len(abut_ex);
3432                 next_pblk = ext4_ext_pblock(abut_ex);
3433                 ee_pblk = ext4_ext_pblock(ex);
3434
3435                 /*
3436                  * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3437                  * upon those conditions:
3438                  * - C1: abut_ex is initialized,
3439                  * - C2: abut_ex is logically abutting ex,
3440                  * - C3: abut_ex is physically abutting ex,
3441                  * - C4: abut_ex can receive the additional blocks without
3442                  *   overflowing the (initialized) length limit.
3443                  */
3444                 if ((!ext4_ext_is_uninitialized(abut_ex)) &&            /*C1*/
3445                     ((map->m_lblk + map_len) == next_lblk) &&           /*C2*/
3446                     ((ee_pblk + ee_len) == next_pblk) &&                /*C3*/
3447                     (next_len < (EXT_INIT_MAX_LEN - map_len))) {        /*C4*/
3448                         err = ext4_ext_get_access(handle, inode, path + depth);
3449                         if (err)
3450                                 goto out;
3451
3452                         trace_ext4_ext_convert_to_initialized_fastpath(inode,
3453                                 map, ex, abut_ex);
3454
3455                         /* Shift the start of abut_ex by 'map_len' blocks */
3456                         abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3457                         ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3458                         ex->ee_len = cpu_to_le16(ee_len - map_len);
3459                         ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3460
3461                         /* Extend abut_ex by 'map_len' blocks */
3462                         abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3463
3464                         /* Result: number of initialized blocks past m_lblk */
3465                         allocated = map_len;
3466                 }
3467         }
3468         if (allocated) {
3469                 /* Mark the block containing both extents as dirty */
3470                 ext4_ext_dirty(handle, inode, path + depth);
3471
3472                 /* Update path to point to the right extent */
3473                 path[depth].p_ext = abut_ex;
3474                 goto out;
3475         } else
3476                 allocated = ee_len - (map->m_lblk - ee_block);
3477
3478         WARN_ON(map->m_lblk < ee_block);
3479         /*
3480          * It is safe to convert extent to initialized via explicit
3481          * zeroout only if extent is fully insde i_size or new_size.
3482          */
3483         split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3484
3485         if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3486                 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3487                         (inode->i_sb->s_blocksize_bits - 10);
3488
3489         /* If extent is less than s_max_zeroout_kb, zeroout directly */
3490         if (max_zeroout && (ee_len <= max_zeroout)) {
3491                 err = ext4_ext_zeroout(inode, ex);
3492                 if (err)
3493                         goto out;
3494                 zero_ex.ee_block = ex->ee_block;
3495                 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3496                 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3497
3498                 err = ext4_ext_get_access(handle, inode, path + depth);
3499                 if (err)
3500                         goto out;
3501                 ext4_ext_mark_initialized(ex);
3502                 ext4_ext_try_to_merge(handle, inode, path, ex);
3503                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3504                 goto out;
3505         }
3506
3507         /*
3508          * four cases:
3509          * 1. split the extent into three extents.
3510          * 2. split the extent into two extents, zeroout the first half.
3511          * 3. split the extent into two extents, zeroout the second half.
3512          * 4. split the extent into two extents with out zeroout.
3513          */
3514         split_map.m_lblk = map->m_lblk;
3515         split_map.m_len = map->m_len;
3516
3517         if (max_zeroout && (allocated > map->m_len)) {
3518                 if (allocated <= max_zeroout) {
3519                         /* case 3 */
3520                         zero_ex.ee_block =
3521                                          cpu_to_le32(map->m_lblk);
3522                         zero_ex.ee_len = cpu_to_le16(allocated);
3523                         ext4_ext_store_pblock(&zero_ex,
3524                                 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3525                         err = ext4_ext_zeroout(inode, &zero_ex);
3526                         if (err)
3527                                 goto out;
3528                         split_map.m_lblk = map->m_lblk;
3529                         split_map.m_len = allocated;
3530                 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3531                         /* case 2 */
3532                         if (map->m_lblk != ee_block) {
3533                                 zero_ex.ee_block = ex->ee_block;
3534                                 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3535                                                         ee_block);
3536                                 ext4_ext_store_pblock(&zero_ex,
3537                                                       ext4_ext_pblock(ex));
3538                                 err = ext4_ext_zeroout(inode, &zero_ex);
3539                                 if (err)
3540                                         goto out;
3541                         }
3542
3543                         split_map.m_lblk = ee_block;
3544                         split_map.m_len = map->m_lblk - ee_block + map->m_len;
3545                         allocated = map->m_len;
3546                 }
3547         }
3548
3549         allocated = ext4_split_extent(handle, inode, path,
3550                                       &split_map, split_flag, flags);
3551         if (allocated < 0)
3552                 err = allocated;
3553
3554 out:
3555         /* If we have gotten a failure, don't zero out status tree */
3556         if (!err)
3557                 err = ext4_zeroout_es(inode, &zero_ex);
3558         return err ? err : allocated;
3559 }
3560
3561 /*
3562  * This function is called by ext4_ext_map_blocks() from
3563  * ext4_get_blocks_dio_write() when DIO to write
3564  * to an uninitialized extent.
3565  *
3566  * Writing to an uninitialized extent may result in splitting the uninitialized
3567  * extent into multiple initialized/uninitialized extents (up to three)
3568  * There are three possibilities:
3569  *   a> There is no split required: Entire extent should be uninitialized
3570  *   b> Splits in two extents: Write is happening at either end of the extent
3571  *   c> Splits in three extents: Somone is writing in middle of the extent
3572  *
3573  * One of more index blocks maybe needed if the extent tree grow after
3574  * the uninitialized extent split. To prevent ENOSPC occur at the IO
3575  * complete, we need to split the uninitialized extent before DIO submit
3576  * the IO. The uninitialized extent called at this time will be split
3577  * into three uninitialized extent(at most). After IO complete, the part
3578  * being filled will be convert to initialized by the end_io callback function
3579  * via ext4_convert_unwritten_extents().
3580  *
3581  * Returns the size of uninitialized extent to be written on success.
3582  */
3583 static int ext4_split_unwritten_extents(handle_t *handle,
3584                                         struct inode *inode,
3585                                         struct ext4_map_blocks *map,
3586                                         struct ext4_ext_path *path,
3587                                         int flags)
3588 {
3589         ext4_lblk_t eof_block;
3590         ext4_lblk_t ee_block;
3591         struct ext4_extent *ex;
3592         unsigned int ee_len;
3593         int split_flag = 0, depth;
3594
3595         ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3596                 "block %llu, max_blocks %u\n", inode->i_ino,
3597                 (unsigned long long)map->m_lblk, map->m_len);
3598
3599         eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3600                 inode->i_sb->s_blocksize_bits;
3601         if (eof_block < map->m_lblk + map->m_len)
3602                 eof_block = map->m_lblk + map->m_len;
3603         /*
3604          * It is safe to convert extent to initialized via explicit
3605          * zeroout only if extent is fully insde i_size or new_size.
3606          */
3607         depth = ext_depth(inode);
3608         ex = path[depth].p_ext;
3609         ee_block = le32_to_cpu(ex->ee_block);
3610         ee_len = ext4_ext_get_actual_len(ex);
3611
3612         split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3613         split_flag |= EXT4_EXT_MARK_UNINIT2;
3614         if (flags & EXT4_GET_BLOCKS_CONVERT)
3615                 split_flag |= EXT4_EXT_DATA_VALID2;
3616         flags |= EXT4_GET_BLOCKS_PRE_IO;
3617         return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3618 }
3619
3620 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3621                                                 struct inode *inode,
3622                                                 struct ext4_map_blocks *map,
3623                                                 struct ext4_ext_path *path)
3624 {
3625         struct ext4_extent *ex;
3626         ext4_lblk_t ee_block;
3627         unsigned int ee_len;
3628         int depth;
3629         int err = 0;
3630
3631         depth = ext_depth(inode);
3632         ex = path[depth].p_ext;
3633         ee_block = le32_to_cpu(ex->ee_block);
3634         ee_len = ext4_ext_get_actual_len(ex);
3635
3636         ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3637                 "block %llu, max_blocks %u\n", inode->i_ino,
3638                   (unsigned long long)ee_block, ee_len);
3639
3640         /* If extent is larger than requested it is a clear sign that we still
3641          * have some extent state machine issues left. So extent_split is still
3642          * required.
3643          * TODO: Once all related issues will be fixed this situation should be
3644          * illegal.
3645          */
3646         if (ee_block != map->m_lblk || ee_len > map->m_len) {
3647 #ifdef EXT4_DEBUG
3648                 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3649                              " len %u; IO logical block %llu, len %u\n",
3650                              inode->i_ino, (unsigned long long)ee_block, ee_len,
3651                              (unsigned long long)map->m_lblk, map->m_len);
3652 #endif
3653                 err = ext4_split_unwritten_extents(handle, inode, map, path,
3654                                                    EXT4_GET_BLOCKS_CONVERT);
3655                 if (err < 0)
3656                         goto out;
3657                 ext4_ext_drop_refs(path);
3658                 path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
3659                 if (IS_ERR(path)) {
3660                         err = PTR_ERR(path);
3661                         goto out;
3662                 }
3663                 depth = ext_depth(inode);
3664                 ex = path[depth].p_ext;
3665         }
3666
3667         err = ext4_ext_get_access(handle, inode, path + depth);
3668         if (err)
3669                 goto out;
3670         /* first mark the extent as initialized */
3671         ext4_ext_mark_initialized(ex);
3672
3673         /* note: ext4_ext_correct_indexes() isn't needed here because
3674          * borders are not changed
3675          */
3676         ext4_ext_try_to_merge(handle, inode, path, ex);
3677
3678         /* Mark modified extent as dirty */
3679         err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3680 out:
3681         ext4_ext_show_leaf(inode, path);
3682         return err;
3683 }
3684
3685 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3686                         sector_t block, int count)
3687 {
3688         int i;
3689         for (i = 0; i < count; i++)
3690                 unmap_underlying_metadata(bdev, block + i);
3691 }
3692
3693 /*
3694  * Handle EOFBLOCKS_FL flag, clearing it if necessary
3695  */
3696 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3697                               ext4_lblk_t lblk,
3698                               struct ext4_ext_path *path,
3699                               unsigned int len)
3700 {
3701         int i, depth;
3702         struct ext4_extent_header *eh;
3703         struct ext4_extent *last_ex;
3704
3705         if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3706                 return 0;
3707
3708         depth = ext_depth(inode);
3709         eh = path[depth].p_hdr;
3710
3711         /*
3712          * We're going to remove EOFBLOCKS_FL entirely in future so we
3713          * do not care for this case anymore. Simply remove the flag
3714          * if there are no extents.
3715          */
3716         if (unlikely(!eh->eh_entries))
3717                 goto out;
3718         last_ex = EXT_LAST_EXTENT(eh);
3719         /*
3720          * We should clear the EOFBLOCKS_FL flag if we are writing the
3721          * last block in the last extent in the file.  We test this by
3722          * first checking to see if the caller to
3723          * ext4_ext_get_blocks() was interested in the last block (or
3724          * a block beyond the last block) in the current extent.  If
3725          * this turns out to be false, we can bail out from this
3726          * function immediately.
3727          */
3728         if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3729             ext4_ext_get_actual_len(last_ex))
3730                 return 0;
3731         /*
3732          * If the caller does appear to be planning to write at or
3733          * beyond the end of the current extent, we then test to see
3734          * if the current extent is the last extent in the file, by
3735          * checking to make sure it was reached via the rightmost node
3736          * at each level of the tree.
3737          */
3738         for (i = depth-1; i >= 0; i--)
3739                 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3740                         return 0;
3741 out:
3742         ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3743         return ext4_mark_inode_dirty(handle, inode);
3744 }
3745
3746 /**
3747  * ext4_find_delalloc_range: find delayed allocated block in the given range.
3748  *
3749  * Return 1 if there is a delalloc block in the range, otherwise 0.
3750  */
3751 int ext4_find_delalloc_range(struct inode *inode,
3752                              ext4_lblk_t lblk_start,
3753                              ext4_lblk_t lblk_end)
3754 {
3755         struct extent_status es;
3756
3757         ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3758         if (es.es_len == 0)
3759                 return 0; /* there is no delay extent in this tree */
3760         else if (es.es_lblk <= lblk_start &&
3761                  lblk_start < es.es_lblk + es.es_len)
3762                 return 1;
3763         else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3764                 return 1;
3765         else
3766                 return 0;
3767 }
3768
3769 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3770 {
3771         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3772         ext4_lblk_t lblk_start, lblk_end;
3773         lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
3774         lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3775
3776         return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3777 }
3778
3779 /**
3780  * Determines how many complete clusters (out of those specified by the 'map')
3781  * are under delalloc and were reserved quota for.
3782  * This function is called when we are writing out the blocks that were
3783  * originally written with their allocation delayed, but then the space was
3784  * allocated using fallocate() before the delayed allocation could be resolved.
3785  * The cases to look for are:
3786  * ('=' indicated delayed allocated blocks
3787  *  '-' indicates non-delayed allocated blocks)
3788  * (a) partial clusters towards beginning and/or end outside of allocated range
3789  *     are not delalloc'ed.
3790  *      Ex:
3791  *      |----c---=|====c====|====c====|===-c----|
3792  *               |++++++ allocated ++++++|
3793  *      ==> 4 complete clusters in above example
3794  *
3795  * (b) partial cluster (outside of allocated range) towards either end is
3796  *     marked for delayed allocation. In this case, we will exclude that
3797  *     cluster.
3798  *      Ex:
3799  *      |----====c========|========c========|
3800  *           |++++++ allocated ++++++|
3801  *      ==> 1 complete clusters in above example
3802  *
3803  *      Ex:
3804  *      |================c================|
3805  *            |++++++ allocated ++++++|
3806  *      ==> 0 complete clusters in above example
3807  *
3808  * The ext4_da_update_reserve_space will be called only if we
3809  * determine here that there were some "entire" clusters that span
3810  * this 'allocated' range.
3811  * In the non-bigalloc case, this function will just end up returning num_blks
3812  * without ever calling ext4_find_delalloc_range.
3813  */
3814 static unsigned int
3815 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3816                            unsigned int num_blks)
3817 {
3818         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3819         ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3820         ext4_lblk_t lblk_from, lblk_to, c_offset;
3821         unsigned int allocated_clusters = 0;
3822
3823         alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3824         alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3825
3826         /* max possible clusters for this allocation */
3827         allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3828
3829         trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3830
3831         /* Check towards left side */
3832         c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
3833         if (c_offset) {
3834                 lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
3835                 lblk_to = lblk_from + c_offset - 1;
3836
3837                 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3838                         allocated_clusters--;
3839         }
3840
3841         /* Now check towards right. */
3842         c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
3843         if (allocated_clusters && c_offset) {
3844                 lblk_from = lblk_start + num_blks;
3845                 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3846
3847                 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3848                         allocated_clusters--;
3849         }
3850
3851         return allocated_clusters;
3852 }
3853
3854 static int
3855 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3856                         struct ext4_map_blocks *map,
3857                         struct ext4_ext_path *path, int flags,
3858                         unsigned int allocated, ext4_fsblk_t newblock)
3859 {
3860         int ret = 0;
3861         int err = 0;
3862         ext4_io_end_t *io = ext4_inode_aio(inode);
3863
3864         ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3865                   "block %llu, max_blocks %u, flags %x, allocated %u\n",
3866                   inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3867                   flags, allocated);
3868         ext4_ext_show_leaf(inode, path);
3869
3870         /*
3871          * When writing into uninitialized space, we should not fail to
3872          * allocate metadata blocks for the new extent block if needed.
3873          */
3874         flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3875
3876         trace_ext4_ext_handle_uninitialized_extents(inode, map, flags,
3877                                                     allocated, newblock);
3878
3879         /* get_block() before submit the IO, split the extent */
3880         if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3881                 ret = ext4_split_unwritten_extents(handle, inode, map,
3882                                                    path, flags);
3883                 if (ret <= 0)
3884                         goto out;
3885                 /*
3886                  * Flag the inode(non aio case) or end_io struct (aio case)
3887                  * that this IO needs to conversion to written when IO is
3888                  * completed
3889                  */
3890                 if (io)
3891                         ext4_set_io_unwritten_flag(inode, io);
3892                 else
3893                         ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3894                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3895                 if (ext4_should_dioread_nolock(inode))
3896                         map->m_flags |= EXT4_MAP_UNINIT;
3897                 goto out;
3898         }
3899         /* IO end_io complete, convert the filled extent to written */
3900         if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3901                 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
3902                                                         path);
3903                 if (ret >= 0) {
3904                         ext4_update_inode_fsync_trans(handle, inode, 1);
3905                         err = check_eofblocks_fl(handle, inode, map->m_lblk,
3906                                                  path, map->m_len);
3907                 } else
3908                         err = ret;
3909                 map->m_flags |= EXT4_MAP_MAPPED;
3910                 if (allocated > map->m_len)
3911                         allocated = map->m_len;
3912                 map->m_len = allocated;
3913                 goto out2;
3914         }
3915         /* buffered IO case */
3916         /*
3917          * repeat fallocate creation request
3918          * we already have an unwritten extent
3919          */
3920         if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) {
3921                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3922                 goto map_out;
3923         }
3924
3925         /* buffered READ or buffered write_begin() lookup */
3926         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3927                 /*
3928                  * We have blocks reserved already.  We
3929                  * return allocated blocks so that delalloc
3930                  * won't do block reservation for us.  But
3931                  * the buffer head will be unmapped so that
3932                  * a read from the block returns 0s.
3933                  */
3934                 map->m_flags |= EXT4_MAP_UNWRITTEN;
3935                 goto out1;
3936         }
3937
3938         /* buffered write, writepage time, convert*/
3939         ret = ext4_ext_convert_to_initialized(handle, inode, map, path, flags);
3940         if (ret >= 0)
3941                 ext4_update_inode_fsync_trans(handle, inode, 1);
3942 out:
3943         if (ret <= 0) {
3944                 err = ret;
3945                 goto out2;
3946         } else
3947                 allocated = ret;
3948         map->m_flags |= EXT4_MAP_NEW;
3949         /*
3950          * if we allocated more blocks than requested
3951          * we need to make sure we unmap the extra block
3952          * allocated. The actual needed block will get
3953          * unmapped later when we find the buffer_head marked
3954          * new.
3955          */
3956         if (allocated > map->m_len) {
3957                 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3958                                         newblock + map->m_len,
3959                                         allocated - map->m_len);
3960                 allocated = map->m_len;
3961         }
3962         map->m_len = allocated;
3963
3964         /*
3965          * If we have done fallocate with the offset that is already
3966          * delayed allocated, we would have block reservation
3967          * and quota reservation done in the delayed write path.
3968          * But fallocate would have already updated quota and block
3969          * count for this offset. So cancel these reservation
3970          */
3971         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3972                 unsigned int reserved_clusters;
3973                 reserved_clusters = get_reserved_cluster_alloc(inode,
3974                                 map->m_lblk, map->m_len);
3975                 if (reserved_clusters)
3976                         ext4_da_update_reserve_space(inode,
3977                                                      reserved_clusters,
3978                                                      0);
3979         }
3980
3981 map_out:
3982         map->m_flags |= EXT4_MAP_MAPPED;
3983         if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3984                 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3985                                          map->m_len);
3986                 if (err < 0)
3987                         goto out2;
3988         }
3989 out1:
3990         if (allocated > map->m_len)
3991                 allocated = map->m_len;
3992         ext4_ext_show_leaf(inode, path);
3993         map->m_pblk = newblock;
3994         map->m_len = allocated;
3995 out2:
3996         if (path) {
3997                 ext4_ext_drop_refs(path);
3998                 kfree(path);
3999         }
4000         return err ? err : allocated;
4001 }
4002
4003 /*
4004  * get_implied_cluster_alloc - check to see if the requested
4005  * allocation (in the map structure) overlaps with a cluster already
4006  * allocated in an extent.
4007  *      @sb     The filesystem superblock structure
4008  *      @map    The requested lblk->pblk mapping
4009  *      @ex     The extent structure which might contain an implied
4010  *                      cluster allocation
4011  *
4012  * This function is called by ext4_ext_map_blocks() after we failed to
4013  * find blocks that were already in the inode's extent tree.  Hence,
4014  * we know that the beginning of the requested region cannot overlap
4015  * the extent from the inode's extent tree.  There are three cases we
4016  * want to catch.  The first is this case:
4017  *
4018  *               |--- cluster # N--|
4019  *    |--- extent ---|  |---- requested region ---|
4020  *                      |==========|
4021  *
4022  * The second case that we need to test for is this one:
4023  *
4024  *   |--------- cluster # N ----------------|
4025  *         |--- requested region --|   |------- extent ----|
4026  *         |=======================|
4027  *
4028  * The third case is when the requested region lies between two extents
4029  * within the same cluster:
4030  *          |------------- cluster # N-------------|
4031  * |----- ex -----|                  |---- ex_right ----|
4032  *                  |------ requested region ------|
4033  *                  |================|
4034  *
4035  * In each of the above cases, we need to set the map->m_pblk and
4036  * map->m_len so it corresponds to the return the extent labelled as
4037  * "|====|" from cluster #N, since it is already in use for data in
4038  * cluster EXT4_B2C(sbi, map->m_lblk).  We will then return 1 to
4039  * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4040  * as a new "allocated" block region.  Otherwise, we will return 0 and
4041  * ext4_ext_map_blocks() will then allocate one or more new clusters
4042  * by calling ext4_mb_new_blocks().
4043  */
4044 static int get_implied_cluster_alloc(struct super_block *sb,
4045                                      struct ext4_map_blocks *map,
4046                                      struct ext4_extent *ex,
4047                                      struct ext4_ext_path *path)
4048 {
4049         struct ext4_sb_info *sbi = EXT4_SB(sb);
4050         ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
4051         ext4_lblk_t ex_cluster_start, ex_cluster_end;
4052         ext4_lblk_t rr_cluster_start;
4053         ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4054         ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4055         unsigned short ee_len = ext4_ext_get_actual_len(ex);
4056
4057         /* The extent passed in that we are trying to match */
4058         ex_cluster_start = EXT4_B2C(sbi, ee_block);
4059         ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4060
4061         /* The requested region passed into ext4_map_blocks() */
4062         rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4063
4064         if ((rr_cluster_start == ex_cluster_end) ||
4065             (rr_cluster_start == ex_cluster_start)) {
4066                 if (rr_cluster_start == ex_cluster_end)
4067                         ee_start += ee_len - 1;
4068                 map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
4069                         c_offset;
4070                 map->m_len = min(map->m_len,
4071                                  (unsigned) sbi->s_cluster_ratio - c_offset);
4072                 /*
4073                  * Check for and handle this case:
4074                  *
4075                  *   |--------- cluster # N-------------|
4076                  *                     |------- extent ----|
4077                  *         |--- requested region ---|
4078                  *         |===========|
4079                  */
4080
4081                 if (map->m_lblk < ee_block)
4082                         map->m_len = min(map->m_len, ee_block - map->m_lblk);
4083
4084                 /*
4085                  * Check for the case where there is already another allocated
4086                  * block to the right of 'ex' but before the end of the cluster.
4087                  *
4088                  *          |------------- cluster # N-------------|
4089                  * |----- ex -----|                  |---- ex_right ----|
4090                  *                  |------ requested region ------|
4091                  *                  |================|
4092                  */
4093                 if (map->m_lblk > ee_block) {
4094                         ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4095                         map->m_len = min(map->m_len, next - map->m_lblk);
4096                 }
4097
4098                 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4099                 return 1;
4100         }
4101
4102         trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4103         return 0;
4104 }
4105
4106
4107 /*
4108  * Block allocation/map/preallocation routine for extents based files
4109  *
4110  *
4111  * Need to be called with
4112  * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4113  * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4114  *
4115  * return > 0, number of of blocks already mapped/allocated
4116  *          if create == 0 and these are pre-allocated blocks
4117  *              buffer head is unmapped
4118  *          otherwise blocks are mapped
4119  *
4120  * return = 0, if plain look up failed (blocks have not been allocated)
4121  *          buffer head is unmapped
4122  *
4123  * return < 0, error case.
4124  */
4125 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4126                         struct ext4_map_blocks *map, int flags)
4127 {
4128         struct ext4_ext_path *path = NULL;
4129         struct ext4_extent newex, *ex, *ex2;
4130         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4131         ext4_fsblk_t newblock = 0;
4132         int free_on_err = 0, err = 0, depth;
4133         unsigned int allocated = 0, offset = 0;
4134         unsigned int allocated_clusters = 0;
4135         struct ext4_allocation_request ar;
4136         ext4_io_end_t *io = ext4_inode_aio(inode);
4137         ext4_lblk_t cluster_offset;
4138         int set_unwritten = 0;
4139
4140         ext_debug("blocks %u/%u requested for inode %lu\n",
4141                   map->m_lblk, map->m_len, inode->i_ino);
4142         trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4143
4144         /* find extent for this block */
4145         path = ext4_ext_find_extent(inode, map->m_lblk, NULL, 0);
4146         if (IS_ERR(path)) {
4147                 err = PTR_ERR(path);
4148                 path = NULL;
4149                 goto out2;
4150         }
4151
4152         depth = ext_depth(inode);
4153
4154         /*
4155          * consistent leaf must not be empty;
4156          * this situation is possible, though, _during_ tree modification;
4157          * this is why assert can't be put in ext4_ext_find_extent()
4158          */
4159         if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4160                 EXT4_ERROR_INODE(inode, "bad extent address "
4161                                  "lblock: %lu, depth: %d pblock %lld",
4162                                  (unsigned long) map->m_lblk, depth,
4163                                  path[depth].p_block);
4164                 err = -EIO;
4165                 goto out2;
4166         }
4167
4168         ex = path[depth].p_ext;
4169         if (ex) {
4170                 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4171                 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4172                 unsigned short ee_len;
4173
4174                 /*
4175                  * Uninitialized extents are treated as holes, except that
4176                  * we split out initialized portions during a write.
4177                  */
4178                 ee_len = ext4_ext_get_actual_len(ex);
4179
4180                 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4181
4182                 /* if found extent covers block, simply return it */
4183                 if (in_range(map->m_lblk, ee_block, ee_len)) {
4184                         newblock = map->m_lblk - ee_block + ee_start;
4185                         /* number of remaining blocks in the extent */
4186                         allocated = ee_len - (map->m_lblk - ee_block);
4187                         ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4188                                   ee_block, ee_len, newblock);
4189
4190                         if (!ext4_ext_is_uninitialized(ex))
4191                                 goto out;
4192
4193                         allocated = ext4_ext_handle_uninitialized_extents(
4194                                 handle, inode, map, path, flags,
4195                                 allocated, newblock);
4196                         goto out3;
4197                 }
4198         }
4199
4200         if ((sbi->s_cluster_ratio > 1) &&
4201             ext4_find_delalloc_cluster(inode, map->m_lblk))
4202                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4203
4204         /*
4205          * requested block isn't allocated yet;
4206          * we couldn't try to create block if create flag is zero
4207          */
4208         if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4209                 /*
4210                  * put just found gap into cache to speed up
4211                  * subsequent requests
4212                  */
4213                 if ((flags & EXT4_GET_BLOCKS_NO_PUT_HOLE) == 0)
4214                         ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
4215                 goto out2;
4216         }
4217
4218         /*
4219          * Okay, we need to do block allocation.
4220          */
4221         map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
4222         newex.ee_block = cpu_to_le32(map->m_lblk);
4223         cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
4224
4225         /*
4226          * If we are doing bigalloc, check to see if the extent returned
4227          * by ext4_ext_find_extent() implies a cluster we can use.
4228          */
4229         if (cluster_offset && ex &&
4230             get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4231                 ar.len = allocated = map->m_len;
4232                 newblock = map->m_pblk;
4233                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4234                 goto got_allocated_blocks;
4235         }
4236
4237         /* find neighbour allocated blocks */
4238         ar.lleft = map->m_lblk;
4239         err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4240         if (err)
4241                 goto out2;
4242         ar.lright = map->m_lblk;
4243         ex2 = NULL;
4244         err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4245         if (err)
4246                 goto out2;
4247
4248         /* Check if the extent after searching to the right implies a
4249          * cluster we can use. */
4250         if ((sbi->s_cluster_ratio > 1) && ex2 &&
4251             get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4252                 ar.len = allocated = map->m_len;
4253                 newblock = map->m_pblk;
4254                 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4255                 goto got_allocated_blocks;
4256         }
4257
4258         /*
4259          * See if request is beyond maximum number of blocks we can have in
4260          * a single extent. For an initialized extent this limit is
4261          * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
4262          * EXT_UNINIT_MAX_LEN.
4263          */
4264         if (map->m_len > EXT_INIT_MAX_LEN &&
4265             !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4266                 map->m_len = EXT_INIT_MAX_LEN;
4267         else if (map->m_len > EXT_UNINIT_MAX_LEN &&
4268                  (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4269                 map->m_len = EXT_UNINIT_MAX_LEN;
4270
4271         /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4272         newex.ee_len = cpu_to_le16(map->m_len);
4273         err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4274         if (err)
4275                 allocated = ext4_ext_get_actual_len(&newex);
4276         else
4277                 allocated = map->m_len;
4278
4279         /* allocate new block */
4280         ar.inode = inode;
4281         ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4282         ar.logical = map->m_lblk;
4283         /*
4284          * We calculate the offset from the beginning of the cluster
4285          * for the logical block number, since when we allocate a
4286          * physical cluster, the physical block should start at the
4287          * same offset from the beginning of the cluster.  This is
4288          * needed so that future calls to get_implied_cluster_alloc()
4289          * work correctly.
4290          */
4291         offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
4292         ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4293         ar.goal -= offset;
4294         ar.logical -= offset;
4295         if (S_ISREG(inode->i_mode))
4296                 ar.flags = EXT4_MB_HINT_DATA;
4297         else
4298                 /* disable in-core preallocation for non-regular files */
4299                 ar.flags = 0;
4300         if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4301                 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4302         newblock = ext4_mb_new_blocks(handle, &ar, &err);
4303         if (!newblock)
4304                 goto out2;
4305         ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4306                   ar.goal, newblock, allocated);
4307         free_on_err = 1;
4308         allocated_clusters = ar.len;
4309         ar.len = EXT4_C2B(sbi, ar.len) - offset;
4310         if (ar.len > allocated)
4311                 ar.len = allocated;
4312
4313 got_allocated_blocks:
4314         /* try to insert new extent into found leaf and return */
4315         ext4_ext_store_pblock(&newex, newblock + offset);
4316         newex.ee_len = cpu_to_le16(ar.len);
4317         /* Mark uninitialized */
4318         if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4319                 ext4_ext_mark_uninitialized(&newex);
4320                 map->m_flags |= EXT4_MAP_UNWRITTEN;
4321                 /*
4322                  * io_end structure was created for every IO write to an
4323                  * uninitialized extent. To avoid unnecessary conversion,
4324                  * here we flag the IO that really needs the conversion.
4325                  * For non asycn direct IO case, flag the inode state
4326                  * that we need to perform conversion when IO is done.
4327                  */
4328                 if ((flags & EXT4_GET_BLOCKS_PRE_IO))
4329                         set_unwritten = 1;
4330                 if (ext4_should_dioread_nolock(inode))
4331                         map->m_flags |= EXT4_MAP_UNINIT;
4332         }
4333
4334         err = 0;
4335         if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4336                 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4337                                          path, ar.len);
4338         if (!err)
4339                 err = ext4_ext_insert_extent(handle, inode, path,
4340                                              &newex, flags);
4341
4342         if (!err && set_unwritten) {
4343                 if (io)
4344                         ext4_set_io_unwritten_flag(inode, io);
4345                 else
4346                         ext4_set_inode_state(inode,
4347                                              EXT4_STATE_DIO_UNWRITTEN);
4348         }
4349
4350         if (err && free_on_err) {
4351                 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4352                         EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4353                 /* free data blocks we just allocated */
4354                 /* not a good idea to call discard here directly,
4355                  * but otherwise we'd need to call it every free() */
4356                 ext4_discard_preallocations(inode);
4357                 ext4_free_blocks(handle, inode, NULL, newblock,
4358                                  EXT4_C2B(sbi, allocated_clusters), fb_flags);
4359                 goto out2;
4360         }
4361
4362         /* previous routine could use block we allocated */
4363         newblock = ext4_ext_pblock(&newex);
4364         allocated = ext4_ext_get_actual_len(&newex);
4365         if (allocated > map->m_len)
4366                 allocated = map->m_len;
4367         map->m_flags |= EXT4_MAP_NEW;
4368
4369         /*
4370          * Update reserved blocks/metadata blocks after successful
4371          * block allocation which had been deferred till now.
4372          */
4373         if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4374                 unsigned int reserved_clusters;
4375                 /*
4376                  * Check how many clusters we had reserved this allocated range
4377                  */
4378                 reserved_clusters = get_reserved_cluster_alloc(inode,
4379                                                 map->m_lblk, allocated);
4380                 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4381                         if (reserved_clusters) {
4382                                 /*
4383                                  * We have clusters reserved for this range.
4384                                  * But since we are not doing actual allocation
4385                                  * and are simply using blocks from previously
4386                                  * allocated cluster, we should release the
4387                                  * reservation and not claim quota.
4388                                  */
4389                                 ext4_da_update_reserve_space(inode,
4390                                                 reserved_clusters, 0);
4391                         }
4392                 } else {
4393                         BUG_ON(allocated_clusters < reserved_clusters);
4394                         if (reserved_clusters < allocated_clusters) {
4395                                 struct ext4_inode_info *ei = EXT4_I(inode);
4396                                 int reservation = allocated_clusters -
4397                                                   reserved_clusters;
4398                                 /*
4399                                  * It seems we claimed few clusters outside of
4400                                  * the range of this allocation. We should give
4401                                  * it back to the reservation pool. This can
4402                                  * happen in the following case:
4403                                  *
4404                                  * * Suppose s_cluster_ratio is 4 (i.e., each
4405                                  *   cluster has 4 blocks. Thus, the clusters
4406                                  *   are [0-3],[4-7],[8-11]...
4407                                  * * First comes delayed allocation write for
4408                                  *   logical blocks 10 & 11. Since there were no
4409                                  *   previous delayed allocated blocks in the
4410                                  *   range [8-11], we would reserve 1 cluster
4411                                  *   for this write.
4412                                  * * Next comes write for logical blocks 3 to 8.
4413                                  *   In this case, we will reserve 2 clusters
4414                                  *   (for [0-3] and [4-7]; and not for [8-11] as
4415                                  *   that range has a delayed allocated blocks.
4416                                  *   Thus total reserved clusters now becomes 3.
4417                                  * * Now, during the delayed allocation writeout
4418                                  *   time, we will first write blocks [3-8] and
4419                                  *   allocate 3 clusters for writing these
4420                                  *   blocks. Also, we would claim all these
4421                                  *   three clusters above.
4422                                  * * Now when we come here to writeout the
4423                                  *   blocks [10-11], we would expect to claim
4424                                  *   the reservation of 1 cluster we had made
4425                                  *   (and we would claim it since there are no
4426                                  *   more delayed allocated blocks in the range
4427                                  *   [8-11]. But our reserved cluster count had
4428                                  *   already gone to 0.
4429                                  *
4430                                  *   Thus, at the step 4 above when we determine
4431                                  *   that there are still some unwritten delayed
4432                                  *   allocated blocks outside of our current
4433                                  *   block range, we should increment the
4434                                  *   reserved clusters count so that when the
4435                                  *   remaining blocks finally gets written, we
4436                                  *   could claim them.
4437                                  */
4438                                 dquot_reserve_block(inode,
4439                                                 EXT4_C2B(sbi, reservation));
4440                                 spin_lock(&ei->i_block_reservation_lock);
4441                                 ei->i_reserved_data_blocks += reservation;
4442                                 spin_unlock(&ei->i_block_reservation_lock);
4443                         }
4444                         /*
4445                          * We will claim quota for all newly allocated blocks.
4446                          * We're updating the reserved space *after* the
4447                          * correction above so we do not accidentally free
4448                          * all the metadata reservation because we might
4449                          * actually need it later on.
4450                          */
4451                         ext4_da_update_reserve_space(inode, allocated_clusters,
4452                                                         1);
4453                 }
4454         }
4455
4456         /*
4457          * Cache the extent and update transaction to commit on fdatasync only
4458          * when it is _not_ an uninitialized extent.
4459          */
4460         if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
4461                 ext4_update_inode_fsync_trans(handle, inode, 1);
4462         else
4463                 ext4_update_inode_fsync_trans(handle, inode, 0);
4464 out:
4465         if (allocated > map->m_len)
4466                 allocated = map->m_len;
4467         ext4_ext_show_leaf(inode, path);
4468         map->m_flags |= EXT4_MAP_MAPPED;
4469         map->m_pblk = newblock;
4470         map->m_len = allocated;
4471 out2:
4472         if (path) {
4473                 ext4_ext_drop_refs(path);
4474                 kfree(path);
4475         }
4476
4477 out3:
4478         trace_ext4_ext_map_blocks_exit(inode, flags, map,
4479                                        err ? err : allocated);
4480         ext4_es_lru_add(inode);
4481         return err ? err : allocated;
4482 }
4483
4484 void ext4_ext_truncate(handle_t *handle, struct inode *inode)
4485 {
4486         struct super_block *sb = inode->i_sb;
4487         ext4_lblk_t last_block;
4488         int err = 0;
4489
4490         /*
4491          * TODO: optimization is possible here.
4492          * Probably we need not scan at all,
4493          * because page truncation is enough.
4494          */
4495
4496         /* we have to know where to truncate from in crash case */
4497         EXT4_I(inode)->i_disksize = inode->i_size;
4498         ext4_mark_inode_dirty(handle, inode);
4499
4500         last_block = (inode->i_size + sb->s_blocksize - 1)
4501                         >> EXT4_BLOCK_SIZE_BITS(sb);
4502 retry:
4503         err = ext4_es_remove_extent(inode, last_block,
4504                                     EXT_MAX_BLOCKS - last_block);
4505         if (err == -ENOMEM) {
4506                 cond_resched();
4507                 congestion_wait(BLK_RW_ASYNC, HZ/50);
4508                 goto retry;
4509         }
4510         if (err) {
4511                 ext4_std_error(inode->i_sb, err);
4512                 return;
4513         }
4514         err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4515         ext4_std_error(inode->i_sb, err);
4516 }
4517
4518 static void ext4_falloc_update_inode(struct inode *inode,
4519                                 int mode, loff_t new_size, int update_ctime)
4520 {
4521         struct timespec now;
4522
4523         if (update_ctime) {
4524                 now = current_fs_time(inode->i_sb);
4525                 if (!timespec_equal(&inode->i_ctime, &now))
4526                         inode->i_ctime = now;
4527         }
4528         /*
4529          * Update only when preallocation was requested beyond
4530          * the file size.
4531          */
4532         if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4533                 if (new_size > i_size_read(inode))
4534                         i_size_write(inode, new_size);
4535                 if (new_size > EXT4_I(inode)->i_disksize)
4536                         ext4_update_i_disksize(inode, new_size);
4537         } else {
4538                 /*
4539                  * Mark that we allocate beyond EOF so the subsequent truncate
4540                  * can proceed even if the new size is the same as i_size.
4541                  */
4542                 if (new_size > i_size_read(inode))
4543                         ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4544         }
4545
4546 }
4547
4548 /*
4549  * preallocate space for a file. This implements ext4's fallocate file
4550  * operation, which gets called from sys_fallocate system call.
4551  * For block-mapped files, posix_fallocate should fall back to the method
4552  * of writing zeroes to the required new blocks (the same behavior which is
4553  * expected for file systems which do not support fallocate() system call).
4554  */
4555 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4556 {
4557         struct inode *inode = file_inode(file);
4558         handle_t *handle;
4559         loff_t new_size;
4560         unsigned int max_blocks;
4561         int ret = 0;
4562         int ret2 = 0;
4563         int retries = 0;
4564         int flags;
4565         struct ext4_map_blocks map;
4566         unsigned int credits, blkbits = inode->i_blkbits;
4567
4568         /* Return error if mode is not supported */
4569         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4570                 return -EOPNOTSUPP;
4571
4572         if (mode & FALLOC_FL_PUNCH_HOLE)
4573                 return ext4_punch_hole(inode, offset, len);
4574
4575         ret = ext4_convert_inline_data(inode);
4576         if (ret)
4577                 return ret;
4578
4579         /*
4580          * currently supporting (pre)allocate mode for extent-based
4581          * files _only_
4582          */
4583         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4584                 return -EOPNOTSUPP;
4585
4586         trace_ext4_fallocate_enter(inode, offset, len, mode);
4587         map.m_lblk = offset >> blkbits;
4588         /*
4589          * We can't just convert len to max_blocks because
4590          * If blocksize = 4096 offset = 3072 and len = 2048
4591          */
4592         max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4593                 - map.m_lblk;
4594         /*
4595          * credits to insert 1 extent into extent tree
4596          */
4597         credits = ext4_chunk_trans_blocks(inode, max_blocks);
4598         mutex_lock(&inode->i_mutex);
4599         ret = inode_newsize_ok(inode, (len + offset));
4600         if (ret) {
4601                 mutex_unlock(&inode->i_mutex);
4602                 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4603                 return ret;
4604         }
4605         flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4606         if (mode & FALLOC_FL_KEEP_SIZE)
4607                 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4608         /*
4609          * Don't normalize the request if it can fit in one extent so
4610          * that it doesn't get unnecessarily split into multiple
4611          * extents.
4612          */
4613         if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4614                 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4615
4616 retry:
4617         while (ret >= 0 && ret < max_blocks) {
4618                 map.m_lblk = map.m_lblk + ret;
4619                 map.m_len = max_blocks = max_blocks - ret;
4620                 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4621                                             credits);
4622                 if (IS_ERR(handle)) {
4623                         ret = PTR_ERR(handle);
4624                         break;
4625                 }
4626                 ret = ext4_map_blocks(handle, inode, &map, flags);
4627                 if (ret <= 0) {
4628 #ifdef EXT4FS_DEBUG
4629                         ext4_warning(inode->i_sb,
4630                                      "inode #%lu: block %u: len %u: "
4631                                      "ext4_ext_map_blocks returned %d",
4632                                      inode->i_ino, map.m_lblk,
4633                                      map.m_len, ret);
4634 #endif
4635                         ext4_mark_inode_dirty(handle, inode);
4636                         ret2 = ext4_journal_stop(handle);
4637                         break;
4638                 }
4639                 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4640                                                 blkbits) >> blkbits))
4641                         new_size = offset + len;
4642                 else
4643                         new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4644
4645                 ext4_falloc_update_inode(inode, mode, new_size,
4646                                          (map.m_flags & EXT4_MAP_NEW));
4647                 ext4_mark_inode_dirty(handle, inode);
4648                 if ((file->f_flags & O_SYNC) && ret >= max_blocks)
4649                         ext4_handle_sync(handle);
4650                 ret2 = ext4_journal_stop(handle);
4651                 if (ret2)
4652                         break;
4653         }
4654         if (ret == -ENOSPC &&
4655                         ext4_should_retry_alloc(inode->i_sb, &retries)) {
4656                 ret = 0;
4657                 goto retry;
4658         }
4659         mutex_unlock(&inode->i_mutex);
4660         trace_ext4_fallocate_exit(inode, offset, max_blocks,
4661                                 ret > 0 ? ret2 : ret);
4662         return ret > 0 ? ret2 : ret;
4663 }
4664
4665 /*
4666  * This function convert a range of blocks to written extents
4667  * The caller of this function will pass the start offset and the size.
4668  * all unwritten extents within this range will be converted to
4669  * written extents.
4670  *
4671  * This function is called from the direct IO end io call back
4672  * function, to convert the fallocated extents after IO is completed.
4673  * Returns 0 on success.
4674  */
4675 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4676                                    loff_t offset, ssize_t len)
4677 {
4678         unsigned int max_blocks;
4679         int ret = 0;
4680         int ret2 = 0;
4681         struct ext4_map_blocks map;
4682         unsigned int credits, blkbits = inode->i_blkbits;
4683
4684         map.m_lblk = offset >> blkbits;
4685         /*
4686          * We can't just convert len to max_blocks because
4687          * If blocksize = 4096 offset = 3072 and len = 2048
4688          */
4689         max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4690                       map.m_lblk);
4691         /*
4692          * This is somewhat ugly but the idea is clear: When transaction is
4693          * reserved, everything goes into it. Otherwise we rather start several
4694          * smaller transactions for conversion of each extent separately.
4695          */
4696         if (handle) {
4697                 handle = ext4_journal_start_reserved(handle,
4698                                                      EXT4_HT_EXT_CONVERT);
4699                 if (IS_ERR(handle))
4700                         return PTR_ERR(handle);
4701                 credits = 0;
4702         } else {
4703                 /*
4704                  * credits to insert 1 extent into extent tree
4705                  */
4706                 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4707         }
4708         while (ret >= 0 && ret < max_blocks) {
4709                 map.m_lblk += ret;
4710                 map.m_len = (max_blocks -= ret);
4711                 if (credits) {
4712                         handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4713                                                     credits);
4714                         if (IS_ERR(handle)) {
4715                                 ret = PTR_ERR(handle);
4716                                 break;
4717                         }
4718                 }
4719                 ret = ext4_map_blocks(handle, inode, &map,
4720                                       EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4721                 if (ret <= 0)
4722                         ext4_warning(inode->i_sb,
4723                                      "inode #%lu: block %u: len %u: "
4724                                      "ext4_ext_map_blocks returned %d",
4725                                      inode->i_ino, map.m_lblk,
4726                                      map.m_len, ret);
4727                 ext4_mark_inode_dirty(handle, inode);
4728                 if (credits)
4729                         ret2 = ext4_journal_stop(handle);
4730                 if (ret <= 0 || ret2)
4731                         break;
4732         }
4733         if (!credits)
4734                 ret2 = ext4_journal_stop(handle);
4735         return ret > 0 ? ret2 : ret;
4736 }
4737
4738 /*
4739  * If newes is not existing extent (newes->ec_pblk equals zero) find
4740  * delayed extent at start of newes and update newes accordingly and
4741  * return start of the next delayed extent.
4742  *
4743  * If newes is existing extent (newes->ec_pblk is not equal zero)
4744  * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
4745  * extent found. Leave newes unmodified.
4746  */
4747 static int ext4_find_delayed_extent(struct inode *inode,
4748                                     struct extent_status *newes)
4749 {
4750         struct extent_status es;
4751         ext4_lblk_t block, next_del;
4752
4753         if (newes->es_pblk == 0) {
4754                 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
4755                                 newes->es_lblk + newes->es_len - 1, &es);
4756
4757                 /*
4758                  * No extent in extent-tree contains block @newes->es_pblk,
4759                  * then the block may stay in 1)a hole or 2)delayed-extent.
4760                  */
4761                 if (es.es_len == 0)
4762                         /* A hole found. */
4763                         return 0;
4764
4765                 if (es.es_lblk > newes->es_lblk) {
4766                         /* A hole found. */
4767                         newes->es_len = min(es.es_lblk - newes->es_lblk,
4768                                             newes->es_len);
4769                         return 0;
4770                 }
4771
4772                 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
4773         }
4774
4775         block = newes->es_lblk + newes->es_len;
4776         ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
4777         if (es.es_len == 0)
4778                 next_del = EXT_MAX_BLOCKS;
4779         else
4780                 next_del = es.es_lblk;
4781
4782         return next_del;
4783 }
4784 /* fiemap flags we can handle specified here */
4785 #define EXT4_FIEMAP_FLAGS       (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4786
4787 static int ext4_xattr_fiemap(struct inode *inode,
4788                                 struct fiemap_extent_info *fieinfo)
4789 {
4790         __u64 physical = 0;
4791         __u64 length;
4792         __u32 flags = FIEMAP_EXTENT_LAST;
4793         int blockbits = inode->i_sb->s_blocksize_bits;
4794         int error = 0;
4795
4796         /* in-inode? */
4797         if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4798                 struct ext4_iloc iloc;
4799                 int offset;     /* offset of xattr in inode */
4800
4801                 error = ext4_get_inode_loc(inode, &iloc);
4802                 if (error)
4803                         return error;
4804                 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4805                 offset = EXT4_GOOD_OLD_INODE_SIZE +
4806                                 EXT4_I(inode)->i_extra_isize;
4807                 physical += offset;
4808                 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4809                 flags |= FIEMAP_EXTENT_DATA_INLINE;
4810                 brelse(iloc.bh);
4811         } else { /* external block */
4812                 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4813                 length = inode->i_sb->s_blocksize;
4814         }
4815
4816         if (physical)
4817                 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4818                                                 length, flags);
4819         return (error < 0 ? error : 0);
4820 }
4821
4822 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4823                 __u64 start, __u64 len)
4824 {
4825         ext4_lblk_t start_blk;
4826         int error = 0;
4827
4828         if (ext4_has_inline_data(inode)) {
4829                 int has_inline = 1;
4830
4831                 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline);
4832
4833                 if (has_inline)
4834                         return error;
4835         }
4836
4837         if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4838                 error = ext4_ext_precache(inode);
4839                 if (error)
4840                         return error;
4841         }
4842
4843         /* fallback to generic here if not in extents fmt */
4844         if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4845                 return generic_block_fiemap(inode, fieinfo, start, len,
4846                         ext4_get_block);
4847
4848         if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4849                 return -EBADR;
4850
4851         if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4852                 error = ext4_xattr_fiemap(inode, fieinfo);
4853         } else {
4854                 ext4_lblk_t len_blks;
4855                 __u64 last_blk;
4856
4857                 start_blk = start >> inode->i_sb->s_blocksize_bits;
4858                 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4859                 if (last_blk >= EXT_MAX_BLOCKS)
4860                         last_blk = EXT_MAX_BLOCKS-1;
4861                 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4862
4863                 /*
4864                  * Walk the extent tree gathering extent information
4865                  * and pushing extents back to the user.
4866                  */
4867                 error = ext4_fill_fiemap_extents(inode, start_blk,
4868                                                  len_blks, fieinfo);
4869         }
4870         ext4_es_lru_add(inode);
4871         return error;
4872 }