Merge remote-tracking branch 'lsk/v3.10/topic/of' into linux-linaro-lsk
[firefly-linux-kernel-4.4.55.git] / fs / reiserfs / dir.c
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4
5 #include <linux/string.h>
6 #include <linux/errno.h>
7 #include <linux/fs.h>
8 #include "reiserfs.h"
9 #include <linux/stat.h>
10 #include <linux/buffer_head.h>
11 #include <linux/slab.h>
12 #include <asm/uaccess.h>
13
14 extern const struct reiserfs_key MIN_KEY;
15
16 static int reiserfs_readdir(struct file *, void *, filldir_t);
17 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
18                               int datasync);
19
20 const struct file_operations reiserfs_dir_operations = {
21         .llseek = generic_file_llseek,
22         .read = generic_read_dir,
23         .readdir = reiserfs_readdir,
24         .fsync = reiserfs_dir_fsync,
25         .unlocked_ioctl = reiserfs_ioctl,
26 #ifdef CONFIG_COMPAT
27         .compat_ioctl = reiserfs_compat_ioctl,
28 #endif
29 };
30
31 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
32                               int datasync)
33 {
34         struct inode *inode = filp->f_mapping->host;
35         int err;
36
37         err = filemap_write_and_wait_range(inode->i_mapping, start, end);
38         if (err)
39                 return err;
40
41         mutex_lock(&inode->i_mutex);
42         reiserfs_write_lock(inode->i_sb);
43         err = reiserfs_commit_for_inode(inode);
44         reiserfs_write_unlock(inode->i_sb);
45         mutex_unlock(&inode->i_mutex);
46         if (err < 0)
47                 return err;
48         return 0;
49 }
50
51 #define store_ih(where,what) copy_item_head (where, what)
52
53 static inline bool is_privroot_deh(struct dentry *dir,
54                                    struct reiserfs_de_head *deh)
55 {
56         struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
57         return (dir == dir->d_parent && privroot->d_inode &&
58                 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
59 }
60
61 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
62                            filldir_t filldir, loff_t *pos)
63 {
64         struct inode *inode = dentry->d_inode;
65         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
66         INITIALIZE_PATH(path_to_entry);
67         struct buffer_head *bh;
68         int item_num, entry_num;
69         const struct reiserfs_key *rkey;
70         struct item_head *ih, tmp_ih;
71         int search_res;
72         char *local_buf;
73         loff_t next_pos;
74         char small_buf[32];     /* avoid kmalloc if we can */
75         struct reiserfs_dir_entry de;
76         int ret = 0;
77
78         reiserfs_write_lock(inode->i_sb);
79
80         reiserfs_check_lock_depth(inode->i_sb, "readdir");
81
82         /* form key for search the next directory entry using f_pos field of
83            file structure */
84         make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
85         next_pos = cpu_key_k_offset(&pos_key);
86
87         path_to_entry.reada = PATH_READA;
88         while (1) {
89               research:
90                 /* search the directory item, containing entry with specified key */
91                 search_res =
92                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
93                                         &de);
94                 if (search_res == IO_ERROR) {
95                         // FIXME: we could just skip part of directory which could
96                         // not be read
97                         ret = -EIO;
98                         goto out;
99                 }
100                 entry_num = de.de_entry_num;
101                 bh = de.de_bh;
102                 item_num = de.de_item_num;
103                 ih = de.de_ih;
104                 store_ih(&tmp_ih, ih);
105
106                 /* we must have found item, that is item of this directory, */
107                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
108                        "vs-9000: found item %h does not match to dir we readdir %K",
109                        ih, &pos_key);
110                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
111                        "vs-9005 item_num == %d, item amount == %d",
112                        item_num, B_NR_ITEMS(bh));
113
114                 /* and entry must be not more than number of entries in the item */
115                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
116                        "vs-9010: entry number is too big %d (%d)",
117                        entry_num, I_ENTRY_COUNT(ih));
118
119                 if (search_res == POSITION_FOUND
120                     || entry_num < I_ENTRY_COUNT(ih)) {
121                         /* go through all entries in the directory item beginning from the entry, that has been found */
122                         struct reiserfs_de_head *deh =
123                             B_I_DEH(bh, ih) + entry_num;
124
125                         for (; entry_num < I_ENTRY_COUNT(ih);
126                              entry_num++, deh++) {
127                                 int d_reclen;
128                                 char *d_name;
129                                 off_t d_off;
130                                 ino_t d_ino;
131                                 loff_t cur_pos = deh_offset(deh);
132
133                                 if (!de_visible(deh))
134                                         /* it is hidden entry */
135                                         continue;
136                                 d_reclen = entry_length(bh, ih, entry_num);
137                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
138
139                                 if (d_reclen <= 0 ||
140                                     d_name + d_reclen > bh->b_data + bh->b_size) {
141                                         /* There is corrupted data in entry,
142                                          * We'd better stop here */
143                                         pathrelse(&path_to_entry);
144                                         ret = -EIO;
145                                         goto out;
146                                 }
147
148                                 if (!d_name[d_reclen - 1])
149                                         d_reclen = strlen(d_name);
150
151                                 if (d_reclen >
152                                     REISERFS_MAX_NAME(inode->i_sb->
153                                                       s_blocksize)) {
154                                         /* too big to send back to VFS */
155                                         continue;
156                                 }
157
158                                 /* Ignore the .reiserfs_priv entry */
159                                 if (is_privroot_deh(dentry, deh))
160                                         continue;
161
162                                 d_off = deh_offset(deh);
163                                 *pos = d_off;
164                                 d_ino = deh_objectid(deh);
165                                 if (d_reclen <= 32) {
166                                         local_buf = small_buf;
167                                 } else {
168                                         local_buf = kmalloc(d_reclen,
169                                                             GFP_NOFS);
170                                         if (!local_buf) {
171                                                 pathrelse(&path_to_entry);
172                                                 ret = -ENOMEM;
173                                                 goto out;
174                                         }
175                                         if (item_moved(&tmp_ih, &path_to_entry)) {
176                                                 kfree(local_buf);
177                                                 goto research;
178                                         }
179                                 }
180                                 // Note, that we copy name to user space via temporary
181                                 // buffer (local_buf) because filldir will block if
182                                 // user space buffer is swapped out. At that time
183                                 // entry can move to somewhere else
184                                 memcpy(local_buf, d_name, d_reclen);
185
186                                 /*
187                                  * Since filldir might sleep, we can release
188                                  * the write lock here for other waiters
189                                  */
190                                 reiserfs_write_unlock(inode->i_sb);
191                                 if (filldir
192                                     (dirent, local_buf, d_reclen, d_off, d_ino,
193                                      DT_UNKNOWN) < 0) {
194                                         reiserfs_write_lock(inode->i_sb);
195                                         if (local_buf != small_buf) {
196                                                 kfree(local_buf);
197                                         }
198                                         goto end;
199                                 }
200                                 reiserfs_write_lock(inode->i_sb);
201                                 if (local_buf != small_buf) {
202                                         kfree(local_buf);
203                                 }
204
205                                 /* deh_offset(deh) may be invalid now. */
206                                 next_pos = cur_pos + 1;
207
208                                 if (item_moved(&tmp_ih, &path_to_entry)) {
209                                         set_cpu_key_k_offset(&pos_key,
210                                                              next_pos);
211                                         goto research;
212                                 }
213                         }       /* for */
214                 }
215
216                 if (item_num != B_NR_ITEMS(bh) - 1)
217                         // end of directory has been reached
218                         goto end;
219
220                 /* item we went through is last item of node. Using right
221                    delimiting key check is it directory end */
222                 rkey = get_rkey(&path_to_entry, inode->i_sb);
223                 if (!comp_le_keys(rkey, &MIN_KEY)) {
224                         /* set pos_key to key, that is the smallest and greater
225                            that key of the last entry in the item */
226                         set_cpu_key_k_offset(&pos_key, next_pos);
227                         continue;
228                 }
229
230                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
231                         // end of directory has been reached
232                         goto end;
233                 }
234
235                 /* directory continues in the right neighboring block */
236                 set_cpu_key_k_offset(&pos_key,
237                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
238
239         }                       /* while */
240
241 end:
242         *pos = next_pos;
243         pathrelse(&path_to_entry);
244         reiserfs_check_path(&path_to_entry);
245 out:
246         reiserfs_write_unlock(inode->i_sb);
247         return ret;
248 }
249
250 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
251 {
252         struct dentry *dentry = file->f_path.dentry;
253         return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
254 }
255
256 /* compose directory item containing "." and ".." entries (entries are
257    not aligned to 4 byte boundary) */
258 /* the last four params are LE */
259 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
260                             __le32 par_dirid, __le32 par_objid)
261 {
262         struct reiserfs_de_head *deh;
263
264         memset(body, 0, EMPTY_DIR_SIZE_V1);
265         deh = (struct reiserfs_de_head *)body;
266
267         /* direntry header of "." */
268         put_deh_offset(&(deh[0]), DOT_OFFSET);
269         /* these two are from make_le_item_head, and are are LE */
270         deh[0].deh_dir_id = dirid;
271         deh[0].deh_objectid = objid;
272         deh[0].deh_state = 0;   /* Endian safe if 0 */
273         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
274         mark_de_visible(&(deh[0]));
275
276         /* direntry header of ".." */
277         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
278         /* key of ".." for the root directory */
279         /* these two are from the inode, and are are LE */
280         deh[1].deh_dir_id = par_dirid;
281         deh[1].deh_objectid = par_objid;
282         deh[1].deh_state = 0;   /* Endian safe if 0 */
283         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
284         mark_de_visible(&(deh[1]));
285
286         /* copy ".." and "." */
287         memcpy(body + deh_location(&(deh[0])), ".", 1);
288         memcpy(body + deh_location(&(deh[1])), "..", 2);
289 }
290
291 /* compose directory item containing "." and ".." entries */
292 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
293                          __le32 par_dirid, __le32 par_objid)
294 {
295         struct reiserfs_de_head *deh;
296
297         memset(body, 0, EMPTY_DIR_SIZE);
298         deh = (struct reiserfs_de_head *)body;
299
300         /* direntry header of "." */
301         put_deh_offset(&(deh[0]), DOT_OFFSET);
302         /* these two are from make_le_item_head, and are are LE */
303         deh[0].deh_dir_id = dirid;
304         deh[0].deh_objectid = objid;
305         deh[0].deh_state = 0;   /* Endian safe if 0 */
306         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
307         mark_de_visible(&(deh[0]));
308
309         /* direntry header of ".." */
310         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
311         /* key of ".." for the root directory */
312         /* these two are from the inode, and are are LE */
313         deh[1].deh_dir_id = par_dirid;
314         deh[1].deh_objectid = par_objid;
315         deh[1].deh_state = 0;   /* Endian safe if 0 */
316         put_deh_location(&(deh[1]),
317                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
318         mark_de_visible(&(deh[1]));
319
320         /* copy ".." and "." */
321         memcpy(body + deh_location(&(deh[0])), ".", 1);
322         memcpy(body + deh_location(&(deh[1])), "..", 2);
323 }