include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-2.6.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 <linux/reiserfs_fs.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, struct dentry *dentry,
18                               int datasync);
19
20 const struct file_operations reiserfs_dir_operations = {
21         .read = generic_read_dir,
22         .readdir = reiserfs_readdir,
23         .fsync = reiserfs_dir_fsync,
24         .unlocked_ioctl = reiserfs_ioctl,
25 #ifdef CONFIG_COMPAT
26         .compat_ioctl = reiserfs_compat_ioctl,
27 #endif
28 };
29
30 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
31                               int datasync)
32 {
33         struct inode *inode = dentry->d_inode;
34         int err;
35         reiserfs_write_lock(inode->i_sb);
36         err = reiserfs_commit_for_inode(inode);
37         reiserfs_write_unlock(inode->i_sb);
38         if (err < 0)
39                 return err;
40         return 0;
41 }
42
43 #define store_ih(where,what) copy_item_head (where, what)
44
45 static inline bool is_privroot_deh(struct dentry *dir,
46                                    struct reiserfs_de_head *deh)
47 {
48         struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
49         if (reiserfs_expose_privroot(dir->d_sb))
50                 return 0;
51         return (dir == dir->d_parent && privroot->d_inode &&
52                 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
53 }
54
55 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
56                            filldir_t filldir, loff_t *pos)
57 {
58         struct inode *inode = dentry->d_inode;
59         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
60         INITIALIZE_PATH(path_to_entry);
61         struct buffer_head *bh;
62         int item_num, entry_num;
63         const struct reiserfs_key *rkey;
64         struct item_head *ih, tmp_ih;
65         int search_res;
66         char *local_buf;
67         loff_t next_pos;
68         char small_buf[32];     /* avoid kmalloc if we can */
69         struct reiserfs_dir_entry de;
70         int ret = 0;
71
72         reiserfs_write_lock(inode->i_sb);
73
74         reiserfs_check_lock_depth(inode->i_sb, "readdir");
75
76         /* form key for search the next directory entry using f_pos field of
77            file structure */
78         make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
79         next_pos = cpu_key_k_offset(&pos_key);
80
81         path_to_entry.reada = PATH_READA;
82         while (1) {
83               research:
84                 /* search the directory item, containing entry with specified key */
85                 search_res =
86                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
87                                         &de);
88                 if (search_res == IO_ERROR) {
89                         // FIXME: we could just skip part of directory which could
90                         // not be read
91                         ret = -EIO;
92                         goto out;
93                 }
94                 entry_num = de.de_entry_num;
95                 bh = de.de_bh;
96                 item_num = de.de_item_num;
97                 ih = de.de_ih;
98                 store_ih(&tmp_ih, ih);
99
100                 /* we must have found item, that is item of this directory, */
101                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
102                        "vs-9000: found item %h does not match to dir we readdir %K",
103                        ih, &pos_key);
104                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
105                        "vs-9005 item_num == %d, item amount == %d",
106                        item_num, B_NR_ITEMS(bh));
107
108                 /* and entry must be not more than number of entries in the item */
109                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
110                        "vs-9010: entry number is too big %d (%d)",
111                        entry_num, I_ENTRY_COUNT(ih));
112
113                 if (search_res == POSITION_FOUND
114                     || entry_num < I_ENTRY_COUNT(ih)) {
115                         /* go through all entries in the directory item beginning from the entry, that has been found */
116                         struct reiserfs_de_head *deh =
117                             B_I_DEH(bh, ih) + entry_num;
118
119                         for (; entry_num < I_ENTRY_COUNT(ih);
120                              entry_num++, deh++) {
121                                 int d_reclen;
122                                 char *d_name;
123                                 off_t d_off;
124                                 ino_t d_ino;
125
126                                 if (!de_visible(deh))
127                                         /* it is hidden entry */
128                                         continue;
129                                 d_reclen = entry_length(bh, ih, entry_num);
130                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
131
132                                 if (d_reclen <= 0 ||
133                                     d_name + d_reclen > bh->b_data + bh->b_size) {
134                                         /* There is corrupted data in entry,
135                                          * We'd better stop here */
136                                         pathrelse(&path_to_entry);
137                                         ret = -EIO;
138                                         goto out;
139                                 }
140
141                                 if (!d_name[d_reclen - 1])
142                                         d_reclen = strlen(d_name);
143
144                                 if (d_reclen >
145                                     REISERFS_MAX_NAME(inode->i_sb->
146                                                       s_blocksize)) {
147                                         /* too big to send back to VFS */
148                                         continue;
149                                 }
150
151                                 /* Ignore the .reiserfs_priv entry */
152                                 if (is_privroot_deh(dentry, deh))
153                                         continue;
154
155                                 d_off = deh_offset(deh);
156                                 *pos = d_off;
157                                 d_ino = deh_objectid(deh);
158                                 if (d_reclen <= 32) {
159                                         local_buf = small_buf;
160                                 } else {
161                                         local_buf = kmalloc(d_reclen,
162                                                             GFP_NOFS);
163                                         if (!local_buf) {
164                                                 pathrelse(&path_to_entry);
165                                                 ret = -ENOMEM;
166                                                 goto out;
167                                         }
168                                         if (item_moved(&tmp_ih, &path_to_entry)) {
169                                                 kfree(local_buf);
170                                                 goto research;
171                                         }
172                                 }
173                                 // Note, that we copy name to user space via temporary
174                                 // buffer (local_buf) because filldir will block if
175                                 // user space buffer is swapped out. At that time
176                                 // entry can move to somewhere else
177                                 memcpy(local_buf, d_name, d_reclen);
178
179                                 /*
180                                  * Since filldir might sleep, we can release
181                                  * the write lock here for other waiters
182                                  */
183                                 reiserfs_write_unlock(inode->i_sb);
184                                 if (filldir
185                                     (dirent, local_buf, d_reclen, d_off, d_ino,
186                                      DT_UNKNOWN) < 0) {
187                                         reiserfs_write_lock(inode->i_sb);
188                                         if (local_buf != small_buf) {
189                                                 kfree(local_buf);
190                                         }
191                                         goto end;
192                                 }
193                                 reiserfs_write_lock(inode->i_sb);
194                                 if (local_buf != small_buf) {
195                                         kfree(local_buf);
196                                 }
197                                 // next entry should be looked for with such offset
198                                 next_pos = deh_offset(deh) + 1;
199
200                                 if (item_moved(&tmp_ih, &path_to_entry)) {
201                                         goto research;
202                                 }
203                         }       /* for */
204                 }
205
206                 if (item_num != B_NR_ITEMS(bh) - 1)
207                         // end of directory has been reached
208                         goto end;
209
210                 /* item we went through is last item of node. Using right
211                    delimiting key check is it directory end */
212                 rkey = get_rkey(&path_to_entry, inode->i_sb);
213                 if (!comp_le_keys(rkey, &MIN_KEY)) {
214                         /* set pos_key to key, that is the smallest and greater
215                            that key of the last entry in the item */
216                         set_cpu_key_k_offset(&pos_key, next_pos);
217                         continue;
218                 }
219
220                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
221                         // end of directory has been reached
222                         goto end;
223                 }
224
225                 /* directory continues in the right neighboring block */
226                 set_cpu_key_k_offset(&pos_key,
227                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
228
229         }                       /* while */
230
231 end:
232         *pos = next_pos;
233         pathrelse(&path_to_entry);
234         reiserfs_check_path(&path_to_entry);
235 out:
236         reiserfs_write_unlock(inode->i_sb);
237         return ret;
238 }
239
240 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
241 {
242         struct dentry *dentry = file->f_path.dentry;
243         return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
244 }
245
246 /* compose directory item containing "." and ".." entries (entries are
247    not aligned to 4 byte boundary) */
248 /* the last four params are LE */
249 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
250                             __le32 par_dirid, __le32 par_objid)
251 {
252         struct reiserfs_de_head *deh;
253
254         memset(body, 0, EMPTY_DIR_SIZE_V1);
255         deh = (struct reiserfs_de_head *)body;
256
257         /* direntry header of "." */
258         put_deh_offset(&(deh[0]), DOT_OFFSET);
259         /* these two are from make_le_item_head, and are are LE */
260         deh[0].deh_dir_id = dirid;
261         deh[0].deh_objectid = objid;
262         deh[0].deh_state = 0;   /* Endian safe if 0 */
263         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
264         mark_de_visible(&(deh[0]));
265
266         /* direntry header of ".." */
267         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
268         /* key of ".." for the root directory */
269         /* these two are from the inode, and are are LE */
270         deh[1].deh_dir_id = par_dirid;
271         deh[1].deh_objectid = par_objid;
272         deh[1].deh_state = 0;   /* Endian safe if 0 */
273         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
274         mark_de_visible(&(deh[1]));
275
276         /* copy ".." and "." */
277         memcpy(body + deh_location(&(deh[0])), ".", 1);
278         memcpy(body + deh_location(&(deh[1])), "..", 2);
279 }
280
281 /* compose directory item containing "." and ".." entries */
282 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
283                          __le32 par_dirid, __le32 par_objid)
284 {
285         struct reiserfs_de_head *deh;
286
287         memset(body, 0, EMPTY_DIR_SIZE);
288         deh = (struct reiserfs_de_head *)body;
289
290         /* direntry header of "." */
291         put_deh_offset(&(deh[0]), DOT_OFFSET);
292         /* these two are from make_le_item_head, and are are LE */
293         deh[0].deh_dir_id = dirid;
294         deh[0].deh_objectid = objid;
295         deh[0].deh_state = 0;   /* Endian safe if 0 */
296         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
297         mark_de_visible(&(deh[0]));
298
299         /* direntry header of ".." */
300         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
301         /* key of ".." for the root directory */
302         /* these two are from the inode, and are are LE */
303         deh[1].deh_dir_id = par_dirid;
304         deh[1].deh_objectid = par_objid;
305         deh[1].deh_state = 0;   /* Endian safe if 0 */
306         put_deh_location(&(deh[1]),
307                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
308         mark_de_visible(&(deh[1]));
309
310         /* copy ".." and "." */
311         memcpy(body + deh_location(&(deh[0])), ".", 1);
312         memcpy(body + deh_location(&(deh[1])), "..", 2);
313 }