Merge remote-tracking branch 'lsk/v3.10/topic/arm64-misc' into linux-linaro-lsk
[firefly-linux-kernel-4.4.55.git] / fs / gfs2 / ops_fstype.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/blkdev.h>
16 #include <linux/kthread.h>
17 #include <linux/export.h>
18 #include <linux/namei.h>
19 #include <linux/mount.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <linux/quotaops.h>
22 #include <linux/lockdep.h>
23 #include <linux/module.h>
24
25 #include "gfs2.h"
26 #include "incore.h"
27 #include "bmap.h"
28 #include "glock.h"
29 #include "glops.h"
30 #include "inode.h"
31 #include "recovery.h"
32 #include "rgrp.h"
33 #include "super.h"
34 #include "sys.h"
35 #include "util.h"
36 #include "log.h"
37 #include "quota.h"
38 #include "dir.h"
39 #include "trace_gfs2.h"
40
41 #define DO 0
42 #define UNDO 1
43
44 /**
45  * gfs2_tune_init - Fill a gfs2_tune structure with default values
46  * @gt: tune
47  *
48  */
49
50 static void gfs2_tune_init(struct gfs2_tune *gt)
51 {
52         spin_lock_init(&gt->gt_spin);
53
54         gt->gt_quota_simul_sync = 64;
55         gt->gt_quota_warn_period = 10;
56         gt->gt_quota_scale_num = 1;
57         gt->gt_quota_scale_den = 1;
58         gt->gt_new_files_jdata = 0;
59         gt->gt_max_readahead = 1 << 18;
60         gt->gt_complain_secs = 10;
61 }
62
63 static struct gfs2_sbd *init_sbd(struct super_block *sb)
64 {
65         struct gfs2_sbd *sdp;
66
67         sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
68         if (!sdp)
69                 return NULL;
70
71         sb->s_fs_info = sdp;
72         sdp->sd_vfs = sb;
73         sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
74         if (!sdp->sd_lkstats) {
75                 kfree(sdp);
76                 return NULL;
77         }
78
79         set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
80         gfs2_tune_init(&sdp->sd_tune);
81
82         init_waitqueue_head(&sdp->sd_glock_wait);
83         atomic_set(&sdp->sd_glock_disposal, 0);
84         init_completion(&sdp->sd_locking_init);
85         init_completion(&sdp->sd_wdack);
86         spin_lock_init(&sdp->sd_statfs_spin);
87
88         spin_lock_init(&sdp->sd_rindex_spin);
89         sdp->sd_rindex_tree.rb_node = NULL;
90
91         INIT_LIST_HEAD(&sdp->sd_jindex_list);
92         spin_lock_init(&sdp->sd_jindex_spin);
93         mutex_init(&sdp->sd_jindex_mutex);
94
95         INIT_LIST_HEAD(&sdp->sd_quota_list);
96         mutex_init(&sdp->sd_quota_mutex);
97         init_waitqueue_head(&sdp->sd_quota_wait);
98         INIT_LIST_HEAD(&sdp->sd_trunc_list);
99         spin_lock_init(&sdp->sd_trunc_lock);
100
101         spin_lock_init(&sdp->sd_log_lock);
102         atomic_set(&sdp->sd_log_pinned, 0);
103         INIT_LIST_HEAD(&sdp->sd_log_le_buf);
104         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
105         INIT_LIST_HEAD(&sdp->sd_log_le_databuf);
106         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
107         spin_lock_init(&sdp->sd_ordered_lock);
108
109         init_waitqueue_head(&sdp->sd_log_waitq);
110         init_waitqueue_head(&sdp->sd_logd_waitq);
111         spin_lock_init(&sdp->sd_ail_lock);
112         INIT_LIST_HEAD(&sdp->sd_ail1_list);
113         INIT_LIST_HEAD(&sdp->sd_ail2_list);
114
115         init_rwsem(&sdp->sd_log_flush_lock);
116         atomic_set(&sdp->sd_log_in_flight, 0);
117         init_waitqueue_head(&sdp->sd_log_flush_wait);
118
119         INIT_LIST_HEAD(&sdp->sd_revoke_list);
120
121         return sdp;
122 }
123
124
125 /**
126  * gfs2_check_sb - Check superblock
127  * @sdp: the filesystem
128  * @sb: The superblock
129  * @silent: Don't print a message if the check fails
130  *
131  * Checks the version code of the FS is one that we understand how to
132  * read and that the sizes of the various on-disk structures have not
133  * changed.
134  */
135
136 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
137 {
138         struct gfs2_sb_host *sb = &sdp->sd_sb;
139
140         if (sb->sb_magic != GFS2_MAGIC ||
141             sb->sb_type != GFS2_METATYPE_SB) {
142                 if (!silent)
143                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
144                 return -EINVAL;
145         }
146
147         /*  If format numbers match exactly, we're done.  */
148
149         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
150             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
151                 return 0;
152
153         fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
154
155         return -EINVAL;
156 }
157
158 static void end_bio_io_page(struct bio *bio, int error)
159 {
160         struct page *page = bio->bi_private;
161
162         if (!error)
163                 SetPageUptodate(page);
164         else
165                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
166         unlock_page(page);
167 }
168
169 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
170 {
171         struct gfs2_sb_host *sb = &sdp->sd_sb;
172         struct super_block *s = sdp->sd_vfs;
173         const struct gfs2_sb *str = buf;
174
175         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
176         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
177         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
178         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
179         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
180         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
181         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
182         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
183         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
184         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
185         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
186
187         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
188         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
189         memcpy(s->s_uuid, str->sb_uuid, 16);
190 }
191
192 /**
193  * gfs2_read_super - Read the gfs2 super block from disk
194  * @sdp: The GFS2 super block
195  * @sector: The location of the super block
196  * @error: The error code to return
197  *
198  * This uses the bio functions to read the super block from disk
199  * because we want to be 100% sure that we never read cached data.
200  * A super block is read twice only during each GFS2 mount and is
201  * never written to by the filesystem. The first time its read no
202  * locks are held, and the only details which are looked at are those
203  * relating to the locking protocol. Once locking is up and working,
204  * the sb is read again under the lock to establish the location of
205  * the master directory (contains pointers to journals etc) and the
206  * root directory.
207  *
208  * Returns: 0 on success or error
209  */
210
211 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
212 {
213         struct super_block *sb = sdp->sd_vfs;
214         struct gfs2_sb *p;
215         struct page *page;
216         struct bio *bio;
217
218         page = alloc_page(GFP_NOFS);
219         if (unlikely(!page))
220                 return -ENOBUFS;
221
222         ClearPageUptodate(page);
223         ClearPageDirty(page);
224         lock_page(page);
225
226         bio = bio_alloc(GFP_NOFS, 1);
227         bio->bi_sector = sector * (sb->s_blocksize >> 9);
228         bio->bi_bdev = sb->s_bdev;
229         bio_add_page(bio, page, PAGE_SIZE, 0);
230
231         bio->bi_end_io = end_bio_io_page;
232         bio->bi_private = page;
233         submit_bio(READ_SYNC | REQ_META, bio);
234         wait_on_page_locked(page);
235         bio_put(bio);
236         if (!PageUptodate(page)) {
237                 __free_page(page);
238                 return -EIO;
239         }
240         p = kmap(page);
241         gfs2_sb_in(sdp, p);
242         kunmap(page);
243         __free_page(page);
244         return gfs2_check_sb(sdp, silent);
245 }
246
247 /**
248  * gfs2_read_sb - Read super block
249  * @sdp: The GFS2 superblock
250  * @silent: Don't print message if mount fails
251  *
252  */
253
254 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
255 {
256         u32 hash_blocks, ind_blocks, leaf_blocks;
257         u32 tmp_blocks;
258         unsigned int x;
259         int error;
260
261         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
262         if (error) {
263                 if (!silent)
264                         fs_err(sdp, "can't read superblock\n");
265                 return error;
266         }
267
268         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
269                                GFS2_BASIC_BLOCK_SHIFT;
270         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
271         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
272                           sizeof(struct gfs2_dinode)) / sizeof(u64);
273         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
274                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
275         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
276         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
277         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
278         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
279         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
280                                 sizeof(struct gfs2_meta_header)) /
281                                 sizeof(struct gfs2_quota_change);
282         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
283                                      sizeof(struct gfs2_meta_header))
284                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
285
286         /* Compute maximum reservation required to add a entry to a directory */
287
288         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
289                              sdp->sd_jbsize);
290
291         ind_blocks = 0;
292         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
293                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
294                 ind_blocks += tmp_blocks;
295         }
296
297         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
298
299         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
300
301         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
302                                 sizeof(struct gfs2_dinode);
303         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
304         for (x = 2;; x++) {
305                 u64 space, d;
306                 u32 m;
307
308                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
309                 d = space;
310                 m = do_div(d, sdp->sd_inptrs);
311
312                 if (d != sdp->sd_heightsize[x - 1] || m)
313                         break;
314                 sdp->sd_heightsize[x] = space;
315         }
316         sdp->sd_max_height = x;
317         sdp->sd_heightsize[x] = ~0;
318         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
319
320         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
321                                  sizeof(struct gfs2_dinode);
322         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
323         for (x = 2;; x++) {
324                 u64 space, d;
325                 u32 m;
326
327                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
328                 d = space;
329                 m = do_div(d, sdp->sd_inptrs);
330
331                 if (d != sdp->sd_jheightsize[x - 1] || m)
332                         break;
333                 sdp->sd_jheightsize[x] = space;
334         }
335         sdp->sd_max_jheight = x;
336         sdp->sd_jheightsize[x] = ~0;
337         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
338
339         return 0;
340 }
341
342 static int init_names(struct gfs2_sbd *sdp, int silent)
343 {
344         char *proto, *table;
345         int error = 0;
346
347         proto = sdp->sd_args.ar_lockproto;
348         table = sdp->sd_args.ar_locktable;
349
350         /*  Try to autodetect  */
351
352         if (!proto[0] || !table[0]) {
353                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
354                 if (error)
355                         return error;
356
357                 if (!proto[0])
358                         proto = sdp->sd_sb.sb_lockproto;
359                 if (!table[0])
360                         table = sdp->sd_sb.sb_locktable;
361         }
362
363         if (!table[0])
364                 table = sdp->sd_vfs->s_id;
365
366         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
367         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
368
369         table = sdp->sd_table_name;
370         while ((table = strchr(table, '/')))
371                 *table = '_';
372
373         return error;
374 }
375
376 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
377                         int undo)
378 {
379         int error = 0;
380
381         if (undo)
382                 goto fail_trans;
383
384         error = gfs2_glock_nq_num(sdp,
385                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
386                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
387                                   mount_gh);
388         if (error) {
389                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
390                 goto fail;
391         }
392
393         error = gfs2_glock_nq_num(sdp,
394                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
395                                   LM_ST_SHARED,
396                                   LM_FLAG_NOEXP | GL_EXACT,
397                                   &sdp->sd_live_gh);
398         if (error) {
399                 fs_err(sdp, "can't acquire live glock: %d\n", error);
400                 goto fail_mount;
401         }
402
403         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
404                                CREATE, &sdp->sd_rename_gl);
405         if (error) {
406                 fs_err(sdp, "can't create rename glock: %d\n", error);
407                 goto fail_live;
408         }
409
410         error = gfs2_glock_get(sdp, GFS2_TRANS_LOCK, &gfs2_trans_glops,
411                                CREATE, &sdp->sd_trans_gl);
412         if (error) {
413                 fs_err(sdp, "can't create transaction glock: %d\n", error);
414                 goto fail_rename;
415         }
416
417         return 0;
418
419 fail_trans:
420         gfs2_glock_put(sdp->sd_trans_gl);
421 fail_rename:
422         gfs2_glock_put(sdp->sd_rename_gl);
423 fail_live:
424         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
425 fail_mount:
426         gfs2_glock_dq_uninit(mount_gh);
427 fail:
428         return error;
429 }
430
431 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
432                             u64 no_addr, const char *name)
433 {
434         struct gfs2_sbd *sdp = sb->s_fs_info;
435         struct dentry *dentry;
436         struct inode *inode;
437
438         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
439         if (IS_ERR(inode)) {
440                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
441                 return PTR_ERR(inode);
442         }
443         dentry = d_make_root(inode);
444         if (!dentry) {
445                 fs_err(sdp, "can't alloc %s dentry\n", name);
446                 return -ENOMEM;
447         }
448         *dptr = dentry;
449         return 0;
450 }
451
452 static int init_sb(struct gfs2_sbd *sdp, int silent)
453 {
454         struct super_block *sb = sdp->sd_vfs;
455         struct gfs2_holder sb_gh;
456         u64 no_addr;
457         int ret;
458
459         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
460                                 LM_ST_SHARED, 0, &sb_gh);
461         if (ret) {
462                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
463                 return ret;
464         }
465
466         ret = gfs2_read_sb(sdp, silent);
467         if (ret) {
468                 fs_err(sdp, "can't read superblock: %d\n", ret);
469                 goto out;
470         }
471
472         /* Set up the buffer cache and SB for real */
473         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
474                 ret = -EINVAL;
475                 fs_err(sdp, "FS block size (%u) is too small for device "
476                        "block size (%u)\n",
477                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
478                 goto out;
479         }
480         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
481                 ret = -EINVAL;
482                 fs_err(sdp, "FS block size (%u) is too big for machine "
483                        "page size (%u)\n",
484                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
485                 goto out;
486         }
487         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
488
489         /* Get the root inode */
490         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
491         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
492         if (ret)
493                 goto out;
494
495         /* Get the master inode */
496         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
497         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
498         if (ret) {
499                 dput(sdp->sd_root_dir);
500                 goto out;
501         }
502         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
503 out:
504         gfs2_glock_dq_uninit(&sb_gh);
505         return ret;
506 }
507
508 /**
509  * map_journal_extents - create a reusable "extent" mapping from all logical
510  * blocks to all physical blocks for the given journal.  This will save
511  * us time when writing journal blocks.  Most journals will have only one
512  * extent that maps all their logical blocks.  That's because gfs2.mkfs
513  * arranges the journal blocks sequentially to maximize performance.
514  * So the extent would map the first block for the entire file length.
515  * However, gfs2_jadd can happen while file activity is happening, so
516  * those journals may not be sequential.  Less likely is the case where
517  * the users created their own journals by mounting the metafs and
518  * laying it out.  But it's still possible.  These journals might have
519  * several extents.
520  *
521  * TODO: This should be done in bigger chunks rather than one block at a time,
522  *       but since it's only done at mount time, I'm not worried about the
523  *       time it takes.
524  */
525 static int map_journal_extents(struct gfs2_sbd *sdp)
526 {
527         struct gfs2_jdesc *jd = sdp->sd_jdesc;
528         unsigned int lb;
529         u64 db, prev_db; /* logical block, disk block, prev disk block */
530         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
531         struct gfs2_journal_extent *jext = NULL;
532         struct buffer_head bh;
533         int rc = 0;
534
535         prev_db = 0;
536
537         for (lb = 0; lb < i_size_read(jd->jd_inode) >> sdp->sd_sb.sb_bsize_shift; lb++) {
538                 bh.b_state = 0;
539                 bh.b_blocknr = 0;
540                 bh.b_size = 1 << ip->i_inode.i_blkbits;
541                 rc = gfs2_block_map(jd->jd_inode, lb, &bh, 0);
542                 db = bh.b_blocknr;
543                 if (rc || !db) {
544                         printk(KERN_INFO "GFS2 journal mapping error %d: lb="
545                                "%u db=%llu\n", rc, lb, (unsigned long long)db);
546                         break;
547                 }
548                 if (!prev_db || db != prev_db + 1) {
549                         jext = kzalloc(sizeof(struct gfs2_journal_extent),
550                                        GFP_KERNEL);
551                         if (!jext) {
552                                 printk(KERN_INFO "GFS2 error: out of memory "
553                                        "mapping journal extents.\n");
554                                 rc = -ENOMEM;
555                                 break;
556                         }
557                         jext->dblock = db;
558                         jext->lblock = lb;
559                         jext->blocks = 1;
560                         list_add_tail(&jext->extent_list, &jd->extent_list);
561                 } else {
562                         jext->blocks++;
563                 }
564                 prev_db = db;
565         }
566         return rc;
567 }
568
569 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
570 {
571         char *message = "FIRSTMOUNT=Done";
572         char *envp[] = { message, NULL };
573
574         fs_info(sdp, "first mount done, others may mount\n");
575
576         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
577                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
578
579         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
580 }
581
582 /**
583  * gfs2_jindex_hold - Grab a lock on the jindex
584  * @sdp: The GFS2 superblock
585  * @ji_gh: the holder for the jindex glock
586  *
587  * Returns: errno
588  */
589
590 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
591 {
592         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
593         struct qstr name;
594         char buf[20];
595         struct gfs2_jdesc *jd;
596         int error;
597
598         name.name = buf;
599
600         mutex_lock(&sdp->sd_jindex_mutex);
601
602         for (;;) {
603                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
604                 if (error)
605                         break;
606
607                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
608                 name.hash = gfs2_disk_hash(name.name, name.len);
609
610                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
611                 if (error == -ENOENT) {
612                         error = 0;
613                         break;
614                 }
615
616                 gfs2_glock_dq_uninit(ji_gh);
617
618                 if (error)
619                         break;
620
621                 error = -ENOMEM;
622                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
623                 if (!jd)
624                         break;
625
626                 INIT_LIST_HEAD(&jd->extent_list);
627                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
628                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
629                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
630                         if (!jd->jd_inode)
631                                 error = -ENOENT;
632                         else
633                                 error = PTR_ERR(jd->jd_inode);
634                         kfree(jd);
635                         break;
636                 }
637
638                 spin_lock(&sdp->sd_jindex_spin);
639                 jd->jd_jid = sdp->sd_journals++;
640                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
641                 spin_unlock(&sdp->sd_jindex_spin);
642         }
643
644         mutex_unlock(&sdp->sd_jindex_mutex);
645
646         return error;
647 }
648
649 static int init_journal(struct gfs2_sbd *sdp, int undo)
650 {
651         struct inode *master = sdp->sd_master_dir->d_inode;
652         struct gfs2_holder ji_gh;
653         struct gfs2_inode *ip;
654         int jindex = 1;
655         int error = 0;
656
657         if (undo) {
658                 jindex = 0;
659                 goto fail_jinode_gh;
660         }
661
662         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
663         if (IS_ERR(sdp->sd_jindex)) {
664                 fs_err(sdp, "can't lookup journal index: %d\n", error);
665                 return PTR_ERR(sdp->sd_jindex);
666         }
667
668         /* Load in the journal index special file */
669
670         error = gfs2_jindex_hold(sdp, &ji_gh);
671         if (error) {
672                 fs_err(sdp, "can't read journal index: %d\n", error);
673                 goto fail;
674         }
675
676         error = -EUSERS;
677         if (!gfs2_jindex_size(sdp)) {
678                 fs_err(sdp, "no journals!\n");
679                 goto fail_jindex;
680         }
681
682         if (sdp->sd_args.ar_spectator) {
683                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
684                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
685                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
686                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
687         } else {
688                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
689                         fs_err(sdp, "can't mount journal #%u\n",
690                                sdp->sd_lockstruct.ls_jid);
691                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
692                                gfs2_jindex_size(sdp),
693                                gfs2_jindex_size(sdp) - 1);
694                         goto fail_jindex;
695                 }
696                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
697
698                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
699                                           &gfs2_journal_glops,
700                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
701                                           &sdp->sd_journal_gh);
702                 if (error) {
703                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
704                         goto fail_jindex;
705                 }
706
707                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
708                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
709                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
710                                            &sdp->sd_jinode_gh);
711                 if (error) {
712                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
713                                error);
714                         goto fail_journal_gh;
715                 }
716
717                 error = gfs2_jdesc_check(sdp->sd_jdesc);
718                 if (error) {
719                         fs_err(sdp, "my journal (%u) is bad: %d\n",
720                                sdp->sd_jdesc->jd_jid, error);
721                         goto fail_jinode_gh;
722                 }
723                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
724                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
725                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
726
727                 /* Map the extents for this journal's blocks */
728                 map_journal_extents(sdp);
729         }
730         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
731
732         if (sdp->sd_lockstruct.ls_first) {
733                 unsigned int x;
734                 for (x = 0; x < sdp->sd_journals; x++) {
735                         error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
736                                                      true);
737                         if (error) {
738                                 fs_err(sdp, "error recovering journal %u: %d\n",
739                                        x, error);
740                                 goto fail_jinode_gh;
741                         }
742                 }
743
744                 gfs2_others_may_mount(sdp);
745         } else if (!sdp->sd_args.ar_spectator) {
746                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
747                 if (error) {
748                         fs_err(sdp, "error recovering my journal: %d\n", error);
749                         goto fail_jinode_gh;
750                 }
751         }
752
753         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
754         gfs2_glock_dq_uninit(&ji_gh);
755         jindex = 0;
756
757         return 0;
758
759 fail_jinode_gh:
760         if (!sdp->sd_args.ar_spectator)
761                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
762 fail_journal_gh:
763         if (!sdp->sd_args.ar_spectator)
764                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
765 fail_jindex:
766         gfs2_jindex_free(sdp);
767         if (jindex)
768                 gfs2_glock_dq_uninit(&ji_gh);
769 fail:
770         iput(sdp->sd_jindex);
771         return error;
772 }
773
774 static struct lock_class_key gfs2_quota_imutex_key;
775
776 static int init_inodes(struct gfs2_sbd *sdp, int undo)
777 {
778         int error = 0;
779         struct inode *master = sdp->sd_master_dir->d_inode;
780
781         if (undo)
782                 goto fail_qinode;
783
784         error = init_journal(sdp, undo);
785         if (error)
786                 goto fail;
787
788         /* Read in the master statfs inode */
789         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
790         if (IS_ERR(sdp->sd_statfs_inode)) {
791                 error = PTR_ERR(sdp->sd_statfs_inode);
792                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
793                 goto fail_journal;
794         }
795
796         /* Read in the resource index inode */
797         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
798         if (IS_ERR(sdp->sd_rindex)) {
799                 error = PTR_ERR(sdp->sd_rindex);
800                 fs_err(sdp, "can't get resource index inode: %d\n", error);
801                 goto fail_statfs;
802         }
803         sdp->sd_rindex_uptodate = 0;
804
805         /* Read in the quota inode */
806         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
807         if (IS_ERR(sdp->sd_quota_inode)) {
808                 error = PTR_ERR(sdp->sd_quota_inode);
809                 fs_err(sdp, "can't get quota file inode: %d\n", error);
810                 goto fail_rindex;
811         }
812         /*
813          * i_mutex on quota files is special. Since this inode is hidden system
814          * file, we are safe to define locking ourselves.
815          */
816         lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
817                           &gfs2_quota_imutex_key);
818
819         error = gfs2_rindex_update(sdp);
820         if (error)
821                 goto fail_qinode;
822
823         return 0;
824
825 fail_qinode:
826         iput(sdp->sd_quota_inode);
827 fail_rindex:
828         gfs2_clear_rgrpd(sdp);
829         iput(sdp->sd_rindex);
830 fail_statfs:
831         iput(sdp->sd_statfs_inode);
832 fail_journal:
833         init_journal(sdp, UNDO);
834 fail:
835         return error;
836 }
837
838 static int init_per_node(struct gfs2_sbd *sdp, int undo)
839 {
840         struct inode *pn = NULL;
841         char buf[30];
842         int error = 0;
843         struct gfs2_inode *ip;
844         struct inode *master = sdp->sd_master_dir->d_inode;
845
846         if (sdp->sd_args.ar_spectator)
847                 return 0;
848
849         if (undo)
850                 goto fail_qc_gh;
851
852         pn = gfs2_lookup_simple(master, "per_node");
853         if (IS_ERR(pn)) {
854                 error = PTR_ERR(pn);
855                 fs_err(sdp, "can't find per_node directory: %d\n", error);
856                 return error;
857         }
858
859         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
860         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
861         if (IS_ERR(sdp->sd_sc_inode)) {
862                 error = PTR_ERR(sdp->sd_sc_inode);
863                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
864                 goto fail;
865         }
866
867         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
868         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
869         if (IS_ERR(sdp->sd_qc_inode)) {
870                 error = PTR_ERR(sdp->sd_qc_inode);
871                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
872                 goto fail_ut_i;
873         }
874
875         iput(pn);
876         pn = NULL;
877
878         ip = GFS2_I(sdp->sd_sc_inode);
879         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
880                                    &sdp->sd_sc_gh);
881         if (error) {
882                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
883                 goto fail_qc_i;
884         }
885
886         ip = GFS2_I(sdp->sd_qc_inode);
887         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
888                                    &sdp->sd_qc_gh);
889         if (error) {
890                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
891                 goto fail_ut_gh;
892         }
893
894         return 0;
895
896 fail_qc_gh:
897         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
898 fail_ut_gh:
899         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
900 fail_qc_i:
901         iput(sdp->sd_qc_inode);
902 fail_ut_i:
903         iput(sdp->sd_sc_inode);
904 fail:
905         if (pn)
906                 iput(pn);
907         return error;
908 }
909
910 static int init_threads(struct gfs2_sbd *sdp, int undo)
911 {
912         struct task_struct *p;
913         int error = 0;
914
915         if (undo)
916                 goto fail_quotad;
917
918         p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
919         error = IS_ERR(p);
920         if (error) {
921                 fs_err(sdp, "can't start logd thread: %d\n", error);
922                 return error;
923         }
924         sdp->sd_logd_process = p;
925
926         p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
927         error = IS_ERR(p);
928         if (error) {
929                 fs_err(sdp, "can't start quotad thread: %d\n", error);
930                 goto fail;
931         }
932         sdp->sd_quotad_process = p;
933
934         return 0;
935
936
937 fail_quotad:
938         kthread_stop(sdp->sd_quotad_process);
939 fail:
940         kthread_stop(sdp->sd_logd_process);
941         return error;
942 }
943
944 static const match_table_t nolock_tokens = {
945         { Opt_jid, "jid=%d\n", },
946         { Opt_err, NULL },
947 };
948
949 static const struct lm_lockops nolock_ops = {
950         .lm_proto_name = "lock_nolock",
951         .lm_put_lock = gfs2_glock_free,
952         .lm_tokens = &nolock_tokens,
953 };
954
955 /**
956  * gfs2_lm_mount - mount a locking protocol
957  * @sdp: the filesystem
958  * @args: mount arguments
959  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
960  *
961  * Returns: errno
962  */
963
964 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
965 {
966         const struct lm_lockops *lm;
967         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
968         struct gfs2_args *args = &sdp->sd_args;
969         const char *proto = sdp->sd_proto_name;
970         const char *table = sdp->sd_table_name;
971         char *o, *options;
972         int ret;
973
974         if (!strcmp("lock_nolock", proto)) {
975                 lm = &nolock_ops;
976                 sdp->sd_args.ar_localflocks = 1;
977 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
978         } else if (!strcmp("lock_dlm", proto)) {
979                 lm = &gfs2_dlm_ops;
980 #endif
981         } else {
982                 printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
983                 return -ENOENT;
984         }
985
986         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
987
988         ls->ls_ops = lm;
989         ls->ls_first = 1;
990
991         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
992                 substring_t tmp[MAX_OPT_ARGS];
993                 int token, option;
994
995                 if (!o || !*o)
996                         continue;
997
998                 token = match_token(o, *lm->lm_tokens, tmp);
999                 switch (token) {
1000                 case Opt_jid:
1001                         ret = match_int(&tmp[0], &option);
1002                         if (ret || option < 0) 
1003                                 goto hostdata_error;
1004                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
1005                                 ls->ls_jid = option;
1006                         break;
1007                 case Opt_id:
1008                 case Opt_nodir:
1009                         /* Obsolete, but left for backward compat purposes */
1010                         break;
1011                 case Opt_first:
1012                         ret = match_int(&tmp[0], &option);
1013                         if (ret || (option != 0 && option != 1))
1014                                 goto hostdata_error;
1015                         ls->ls_first = option;
1016                         break;
1017                 case Opt_err:
1018                 default:
1019 hostdata_error:
1020                         fs_info(sdp, "unknown hostdata (%s)\n", o);
1021                         return -EINVAL;
1022                 }
1023         }
1024
1025         if (lm->lm_mount == NULL) {
1026                 fs_info(sdp, "Now mounting FS...\n");
1027                 complete_all(&sdp->sd_locking_init);
1028                 return 0;
1029         }
1030         ret = lm->lm_mount(sdp, table);
1031         if (ret == 0)
1032                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1033         complete_all(&sdp->sd_locking_init);
1034         return ret;
1035 }
1036
1037 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1038 {
1039         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1040         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1041             lm->lm_unmount)
1042                 lm->lm_unmount(sdp);
1043 }
1044
1045 static int gfs2_journalid_wait(void *word)
1046 {
1047         if (signal_pending(current))
1048                 return -EINTR;
1049         schedule();
1050         return 0;
1051 }
1052
1053 static int wait_on_journal(struct gfs2_sbd *sdp)
1054 {
1055         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1056                 return 0;
1057
1058         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
1059 }
1060
1061 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1062 {
1063         struct super_block *sb = sdp->sd_vfs;
1064         char ro[20];
1065         char spectator[20];
1066         char *envp[] = { ro, spectator, NULL };
1067         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1068         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1069         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1070 }
1071
1072 /**
1073  * fill_super - Read in superblock
1074  * @sb: The VFS superblock
1075  * @data: Mount options
1076  * @silent: Don't complain if it's not a GFS2 filesystem
1077  *
1078  * Returns: errno
1079  */
1080
1081 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1082 {
1083         struct gfs2_sbd *sdp;
1084         struct gfs2_holder mount_gh;
1085         int error;
1086
1087         sdp = init_sbd(sb);
1088         if (!sdp) {
1089                 printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
1090                 return -ENOMEM;
1091         }
1092         sdp->sd_args = *args;
1093
1094         if (sdp->sd_args.ar_spectator) {
1095                 sb->s_flags |= MS_RDONLY;
1096                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1097         }
1098         if (sdp->sd_args.ar_posix_acl)
1099                 sb->s_flags |= MS_POSIXACL;
1100         if (sdp->sd_args.ar_nobarrier)
1101                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1102
1103         sb->s_flags |= MS_NOSEC;
1104         sb->s_magic = GFS2_MAGIC;
1105         sb->s_op = &gfs2_super_ops;
1106         sb->s_d_op = &gfs2_dops;
1107         sb->s_export_op = &gfs2_export_ops;
1108         sb->s_xattr = gfs2_xattr_handlers;
1109         sb->s_qcop = &gfs2_quotactl_ops;
1110         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1111         sb->s_time_gran = 1;
1112         sb->s_maxbytes = MAX_LFS_FILESIZE;
1113
1114         /* Set up the buffer cache and fill in some fake block size values
1115            to allow us to read-in the on-disk superblock. */
1116         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1117         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1118         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1119                                GFS2_BASIC_BLOCK_SHIFT;
1120         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1121
1122         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1123         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1124         if (sdp->sd_args.ar_statfs_quantum) {
1125                 sdp->sd_tune.gt_statfs_slow = 0;
1126                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1127         } else {
1128                 sdp->sd_tune.gt_statfs_slow = 1;
1129                 sdp->sd_tune.gt_statfs_quantum = 30;
1130         }
1131
1132         error = init_names(sdp, silent);
1133         if (error) {
1134                 /* In this case, we haven't initialized sysfs, so we have to
1135                    manually free the sdp. */
1136                 free_percpu(sdp->sd_lkstats);
1137                 kfree(sdp);
1138                 sb->s_fs_info = NULL;
1139                 return error;
1140         }
1141
1142         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1143
1144         error = gfs2_sys_fs_add(sdp);
1145         /*
1146          * If we hit an error here, gfs2_sys_fs_add will have called function
1147          * kobject_put which causes the sysfs usage count to go to zero, which
1148          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1149          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1150          * kobject_put to free sdp.
1151          */
1152         if (error)
1153                 return error;
1154
1155         gfs2_create_debugfs_file(sdp);
1156
1157         error = gfs2_lm_mount(sdp, silent);
1158         if (error)
1159                 goto fail_debug;
1160
1161         error = init_locking(sdp, &mount_gh, DO);
1162         if (error)
1163                 goto fail_lm;
1164
1165         error = init_sb(sdp, silent);
1166         if (error)
1167                 goto fail_locking;
1168
1169         error = wait_on_journal(sdp);
1170         if (error)
1171                 goto fail_sb;
1172
1173         /*
1174          * If user space has failed to join the cluster or some similar
1175          * failure has occurred, then the journal id will contain a
1176          * negative (error) number. This will then be returned to the
1177          * caller (of the mount syscall). We do this even for spectator
1178          * mounts (which just write a jid of 0 to indicate "ok" even though
1179          * the jid is unused in the spectator case)
1180          */
1181         if (sdp->sd_lockstruct.ls_jid < 0) {
1182                 error = sdp->sd_lockstruct.ls_jid;
1183                 sdp->sd_lockstruct.ls_jid = 0;
1184                 goto fail_sb;
1185         }
1186
1187         if (sdp->sd_args.ar_spectator)
1188                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1189                          sdp->sd_table_name);
1190         else
1191                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1192                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1193
1194         error = init_inodes(sdp, DO);
1195         if (error)
1196                 goto fail_sb;
1197
1198         error = init_per_node(sdp, DO);
1199         if (error)
1200                 goto fail_inodes;
1201
1202         error = gfs2_statfs_init(sdp);
1203         if (error) {
1204                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1205                 goto fail_per_node;
1206         }
1207
1208         error = init_threads(sdp, DO);
1209         if (error)
1210                 goto fail_per_node;
1211
1212         if (!(sb->s_flags & MS_RDONLY)) {
1213                 error = gfs2_make_fs_rw(sdp);
1214                 if (error) {
1215                         fs_err(sdp, "can't make FS RW: %d\n", error);
1216                         goto fail_threads;
1217                 }
1218         }
1219
1220         gfs2_glock_dq_uninit(&mount_gh);
1221         gfs2_online_uevent(sdp);
1222         return 0;
1223
1224 fail_threads:
1225         init_threads(sdp, UNDO);
1226 fail_per_node:
1227         init_per_node(sdp, UNDO);
1228 fail_inodes:
1229         init_inodes(sdp, UNDO);
1230 fail_sb:
1231         if (sdp->sd_root_dir)
1232                 dput(sdp->sd_root_dir);
1233         if (sdp->sd_master_dir)
1234                 dput(sdp->sd_master_dir);
1235         if (sb->s_root)
1236                 dput(sb->s_root);
1237         sb->s_root = NULL;
1238 fail_locking:
1239         init_locking(sdp, &mount_gh, UNDO);
1240 fail_lm:
1241         gfs2_gl_hash_clear(sdp);
1242         gfs2_lm_unmount(sdp);
1243 fail_debug:
1244         gfs2_delete_debugfs_file(sdp);
1245         free_percpu(sdp->sd_lkstats);
1246         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1247          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1248         gfs2_sys_fs_del(sdp);
1249         sb->s_fs_info = NULL;
1250         return error;
1251 }
1252
1253 static int set_gfs2_super(struct super_block *s, void *data)
1254 {
1255         s->s_bdev = data;
1256         s->s_dev = s->s_bdev->bd_dev;
1257
1258         /*
1259          * We set the bdi here to the queue backing, file systems can
1260          * overwrite this in ->fill_super()
1261          */
1262         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1263         return 0;
1264 }
1265
1266 static int test_gfs2_super(struct super_block *s, void *ptr)
1267 {
1268         struct block_device *bdev = ptr;
1269         return (bdev == s->s_bdev);
1270 }
1271
1272 /**
1273  * gfs2_mount - Get the GFS2 superblock
1274  * @fs_type: The GFS2 filesystem type
1275  * @flags: Mount flags
1276  * @dev_name: The name of the device
1277  * @data: The mount arguments
1278  *
1279  * Q. Why not use get_sb_bdev() ?
1280  * A. We need to select one of two root directories to mount, independent
1281  *    of whether this is the initial, or subsequent, mount of this sb
1282  *
1283  * Returns: 0 or -ve on error
1284  */
1285
1286 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1287                        const char *dev_name, void *data)
1288 {
1289         struct block_device *bdev;
1290         struct super_block *s;
1291         fmode_t mode = FMODE_READ | FMODE_EXCL;
1292         int error;
1293         struct gfs2_args args;
1294         struct gfs2_sbd *sdp;
1295
1296         if (!(flags & MS_RDONLY))
1297                 mode |= FMODE_WRITE;
1298
1299         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1300         if (IS_ERR(bdev))
1301                 return ERR_CAST(bdev);
1302
1303         /*
1304          * once the super is inserted into the list by sget, s_umount
1305          * will protect the lockfs code from trying to start a snapshot
1306          * while we are mounting
1307          */
1308         mutex_lock(&bdev->bd_fsfreeze_mutex);
1309         if (bdev->bd_fsfreeze_count > 0) {
1310                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1311                 error = -EBUSY;
1312                 goto error_bdev;
1313         }
1314         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1315         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1316         error = PTR_ERR(s);
1317         if (IS_ERR(s))
1318                 goto error_bdev;
1319
1320         if (s->s_root) {
1321                 /*
1322                  * s_umount nests inside bd_mutex during
1323                  * __invalidate_device().  blkdev_put() acquires
1324                  * bd_mutex and can't be called under s_umount.  Drop
1325                  * s_umount temporarily.  This is safe as we're
1326                  * holding an active reference.
1327                  */
1328                 up_write(&s->s_umount);
1329                 blkdev_put(bdev, mode);
1330                 down_write(&s->s_umount);
1331         }
1332
1333         memset(&args, 0, sizeof(args));
1334         args.ar_quota = GFS2_QUOTA_DEFAULT;
1335         args.ar_data = GFS2_DATA_DEFAULT;
1336         args.ar_commit = 30;
1337         args.ar_statfs_quantum = 30;
1338         args.ar_quota_quantum = 60;
1339         args.ar_errors = GFS2_ERRORS_DEFAULT;
1340
1341         error = gfs2_mount_args(&args, data);
1342         if (error) {
1343                 printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
1344                 goto error_super;
1345         }
1346
1347         if (s->s_root) {
1348                 error = -EBUSY;
1349                 if ((flags ^ s->s_flags) & MS_RDONLY)
1350                         goto error_super;
1351         } else {
1352                 char b[BDEVNAME_SIZE];
1353
1354                 s->s_mode = mode;
1355                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1356                 sb_set_blocksize(s, block_size(bdev));
1357                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1358                 if (error)
1359                         goto error_super;
1360                 s->s_flags |= MS_ACTIVE;
1361                 bdev->bd_super = s;
1362         }
1363
1364         sdp = s->s_fs_info;
1365         if (args.ar_meta)
1366                 return dget(sdp->sd_master_dir);
1367         else
1368                 return dget(sdp->sd_root_dir);
1369
1370 error_super:
1371         deactivate_locked_super(s);
1372         return ERR_PTR(error);
1373 error_bdev:
1374         blkdev_put(bdev, mode);
1375         return ERR_PTR(error);
1376 }
1377
1378 static int set_meta_super(struct super_block *s, void *ptr)
1379 {
1380         return -EINVAL;
1381 }
1382
1383 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1384                         int flags, const char *dev_name, void *data)
1385 {
1386         struct super_block *s;
1387         struct gfs2_sbd *sdp;
1388         struct path path;
1389         int error;
1390
1391         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1392         if (error) {
1393                 printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
1394                        dev_name, error);
1395                 return ERR_PTR(error);
1396         }
1397         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1398                  path.dentry->d_inode->i_sb->s_bdev);
1399         path_put(&path);
1400         if (IS_ERR(s)) {
1401                 printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
1402                 return ERR_CAST(s);
1403         }
1404         if ((flags ^ s->s_flags) & MS_RDONLY) {
1405                 deactivate_locked_super(s);
1406                 return ERR_PTR(-EBUSY);
1407         }
1408         sdp = s->s_fs_info;
1409         return dget(sdp->sd_master_dir);
1410 }
1411
1412 static void gfs2_kill_sb(struct super_block *sb)
1413 {
1414         struct gfs2_sbd *sdp = sb->s_fs_info;
1415
1416         if (sdp == NULL) {
1417                 kill_block_super(sb);
1418                 return;
1419         }
1420
1421         gfs2_meta_syncfs(sdp);
1422         dput(sdp->sd_root_dir);
1423         dput(sdp->sd_master_dir);
1424         sdp->sd_root_dir = NULL;
1425         sdp->sd_master_dir = NULL;
1426         shrink_dcache_sb(sb);
1427         gfs2_delete_debugfs_file(sdp);
1428         free_percpu(sdp->sd_lkstats);
1429         kill_block_super(sb);
1430 }
1431
1432 struct file_system_type gfs2_fs_type = {
1433         .name = "gfs2",
1434         .fs_flags = FS_REQUIRES_DEV,
1435         .mount = gfs2_mount,
1436         .kill_sb = gfs2_kill_sb,
1437         .owner = THIS_MODULE,
1438 };
1439 MODULE_ALIAS_FS("gfs2");
1440
1441 struct file_system_type gfs2meta_fs_type = {
1442         .name = "gfs2meta",
1443         .fs_flags = FS_REQUIRES_DEV,
1444         .mount = gfs2_mount_meta,
1445         .owner = THIS_MODULE,
1446 };
1447 MODULE_ALIAS_FS("gfs2meta");