Merge with /shiny/git/linux-2.6/.git
[linux-2.6] / fs / reiserfs / dir.c
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4
5 #include <linux/config.h>
6 #include <linux/string.h>
7 #include <linux/errno.h>
8 #include <linux/fs.h>
9 #include <linux/reiserfs_fs.h>
10 #include <linux/stat.h>
11 #include <linux/smp_lock.h>
12 #include <linux/buffer_head.h>
13 #include <asm/uaccess.h>
14
15 extern struct reiserfs_key MIN_KEY;
16
17 static int reiserfs_readdir(struct file *, void *, filldir_t);
18 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
19                               int datasync);
20
21 struct file_operations reiserfs_dir_operations = {
22         .read = generic_read_dir,
23         .readdir = reiserfs_readdir,
24         .fsync = reiserfs_dir_fsync,
25         .ioctl = reiserfs_ioctl,
26 };
27
28 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
29                               int datasync)
30 {
31         struct inode *inode = dentry->d_inode;
32         int err;
33         reiserfs_write_lock(inode->i_sb);
34         err = reiserfs_commit_for_inode(inode);
35         reiserfs_write_unlock(inode->i_sb);
36         if (err < 0)
37                 return err;
38         return 0;
39 }
40
41 #define store_ih(where,what) copy_item_head (where, what)
42
43 //
44 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
45 {
46         struct inode *inode = filp->f_dentry->d_inode;
47         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
48         INITIALIZE_PATH(path_to_entry);
49         struct buffer_head *bh;
50         int item_num, entry_num;
51         const struct reiserfs_key *rkey;
52         struct item_head *ih, tmp_ih;
53         int search_res;
54         char *local_buf;
55         loff_t next_pos;
56         char small_buf[32];     /* avoid kmalloc if we can */
57         struct reiserfs_dir_entry de;
58         int ret = 0;
59
60         reiserfs_write_lock(inode->i_sb);
61
62         reiserfs_check_lock_depth(inode->i_sb, "readdir");
63
64         /* form key for search the next directory entry using f_pos field of
65            file structure */
66         make_cpu_key(&pos_key, inode,
67                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
68                      3);
69         next_pos = cpu_key_k_offset(&pos_key);
70
71         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
72
73         path_to_entry.reada = PATH_READA;
74         while (1) {
75               research:
76                 /* search the directory item, containing entry with specified key */
77                 search_res =
78                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
79                                         &de);
80                 if (search_res == IO_ERROR) {
81                         // FIXME: we could just skip part of directory which could
82                         // not be read
83                         ret = -EIO;
84                         goto out;
85                 }
86                 entry_num = de.de_entry_num;
87                 bh = de.de_bh;
88                 item_num = de.de_item_num;
89                 ih = de.de_ih;
90                 store_ih(&tmp_ih, ih);
91
92                 /* we must have found item, that is item of this directory, */
93                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
94                        "vs-9000: found item %h does not match to dir we readdir %K",
95                        ih, &pos_key);
96                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
97                        "vs-9005 item_num == %d, item amount == %d",
98                        item_num, B_NR_ITEMS(bh));
99
100                 /* and entry must be not more than number of entries in the item */
101                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
102                        "vs-9010: entry number is too big %d (%d)",
103                        entry_num, I_ENTRY_COUNT(ih));
104
105                 if (search_res == POSITION_FOUND
106                     || entry_num < I_ENTRY_COUNT(ih)) {
107                         /* go through all entries in the directory item beginning from the entry, that has been found */
108                         struct reiserfs_de_head *deh =
109                             B_I_DEH(bh, ih) + entry_num;
110
111                         for (; entry_num < I_ENTRY_COUNT(ih);
112                              entry_num++, deh++) {
113                                 int d_reclen;
114                                 char *d_name;
115                                 off_t d_off;
116                                 ino_t d_ino;
117
118                                 if (!de_visible(deh))
119                                         /* it is hidden entry */
120                                         continue;
121                                 d_reclen = entry_length(bh, ih, entry_num);
122                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
123                                 if (!d_name[d_reclen - 1])
124                                         d_reclen = strlen(d_name);
125
126                                 if (d_reclen >
127                                     REISERFS_MAX_NAME(inode->i_sb->
128                                                       s_blocksize)) {
129                                         /* too big to send back to VFS */
130                                         continue;
131                                 }
132
133                                 /* Ignore the .reiserfs_priv entry */
134                                 if (reiserfs_xattrs(inode->i_sb) &&
135                                     !old_format_only(inode->i_sb) &&
136                                     filp->f_dentry == inode->i_sb->s_root &&
137                                     REISERFS_SB(inode->i_sb)->priv_root &&
138                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
139                                     && deh_objectid(deh) ==
140                                     le32_to_cpu(INODE_PKEY
141                                                 (REISERFS_SB(inode->i_sb)->
142                                                  priv_root->d_inode)->
143                                                 k_objectid)) {
144                                         continue;
145                                 }
146
147                                 d_off = deh_offset(deh);
148                                 filp->f_pos = d_off;
149                                 d_ino = deh_objectid(deh);
150                                 if (d_reclen <= 32) {
151                                         local_buf = small_buf;
152                                 } else {
153                                         local_buf =
154                                             reiserfs_kmalloc(d_reclen, GFP_NOFS,
155                                                              inode->i_sb);
156                                         if (!local_buf) {
157                                                 pathrelse(&path_to_entry);
158                                                 ret = -ENOMEM;
159                                                 goto out;
160                                         }
161                                         if (item_moved(&tmp_ih, &path_to_entry)) {
162                                                 reiserfs_kfree(local_buf,
163                                                                d_reclen,
164                                                                inode->i_sb);
165                                                 goto research;
166                                         }
167                                 }
168                                 // Note, that we copy name to user space via temporary
169                                 // buffer (local_buf) because filldir will block if
170                                 // user space buffer is swapped out. At that time
171                                 // entry can move to somewhere else
172                                 memcpy(local_buf, d_name, d_reclen);
173                                 if (filldir
174                                     (dirent, local_buf, d_reclen, d_off, d_ino,
175                                      DT_UNKNOWN) < 0) {
176                                         if (local_buf != small_buf) {
177                                                 reiserfs_kfree(local_buf,
178                                                                d_reclen,
179                                                                inode->i_sb);
180                                         }
181                                         goto end;
182                                 }
183                                 if (local_buf != small_buf) {
184                                         reiserfs_kfree(local_buf, d_reclen,
185                                                        inode->i_sb);
186                                 }
187                                 // next entry should be looked for with such offset
188                                 next_pos = deh_offset(deh) + 1;
189
190                                 if (item_moved(&tmp_ih, &path_to_entry)) {
191                                         goto research;
192                                 }
193                         }       /* for */
194                 }
195
196                 if (item_num != B_NR_ITEMS(bh) - 1)
197                         // end of directory has been reached
198                         goto end;
199
200                 /* item we went through is last item of node. Using right
201                    delimiting key check is it directory end */
202                 rkey = get_rkey(&path_to_entry, inode->i_sb);
203                 if (!comp_le_keys(rkey, &MIN_KEY)) {
204                         /* set pos_key to key, that is the smallest and greater
205                            that key of the last entry in the item */
206                         set_cpu_key_k_offset(&pos_key, next_pos);
207                         continue;
208                 }
209
210                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
211                         // end of directory has been reached
212                         goto end;
213                 }
214
215                 /* directory continues in the right neighboring block */
216                 set_cpu_key_k_offset(&pos_key,
217                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
218
219         }                       /* while */
220
221       end:
222         filp->f_pos = next_pos;
223         pathrelse(&path_to_entry);
224         reiserfs_check_path(&path_to_entry);
225       out:
226         reiserfs_write_unlock(inode->i_sb);
227         return ret;
228 }
229
230 /* compose directory item containing "." and ".." entries (entries are
231    not aligned to 4 byte boundary) */
232 /* the last four params are LE */
233 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
234                             __le32 par_dirid, __le32 par_objid)
235 {
236         struct reiserfs_de_head *deh;
237
238         memset(body, 0, EMPTY_DIR_SIZE_V1);
239         deh = (struct reiserfs_de_head *)body;
240
241         /* direntry header of "." */
242         put_deh_offset(&(deh[0]), DOT_OFFSET);
243         /* these two are from make_le_item_head, and are are LE */
244         deh[0].deh_dir_id = dirid;
245         deh[0].deh_objectid = objid;
246         deh[0].deh_state = 0;   /* Endian safe if 0 */
247         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
248         mark_de_visible(&(deh[0]));
249
250         /* direntry header of ".." */
251         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
252         /* key of ".." for the root directory */
253         /* these two are from the inode, and are are LE */
254         deh[1].deh_dir_id = par_dirid;
255         deh[1].deh_objectid = par_objid;
256         deh[1].deh_state = 0;   /* Endian safe if 0 */
257         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
258         mark_de_visible(&(deh[1]));
259
260         /* copy ".." and "." */
261         memcpy(body + deh_location(&(deh[0])), ".", 1);
262         memcpy(body + deh_location(&(deh[1])), "..", 2);
263 }
264
265 /* compose directory item containing "." and ".." entries */
266 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
267                          __le32 par_dirid, __le32 par_objid)
268 {
269         struct reiserfs_de_head *deh;
270
271         memset(body, 0, EMPTY_DIR_SIZE);
272         deh = (struct reiserfs_de_head *)body;
273
274         /* direntry header of "." */
275         put_deh_offset(&(deh[0]), DOT_OFFSET);
276         /* these two are from make_le_item_head, and are are LE */
277         deh[0].deh_dir_id = dirid;
278         deh[0].deh_objectid = objid;
279         deh[0].deh_state = 0;   /* Endian safe if 0 */
280         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
281         mark_de_visible(&(deh[0]));
282
283         /* direntry header of ".." */
284         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
285         /* key of ".." for the root directory */
286         /* these two are from the inode, and are are LE */
287         deh[1].deh_dir_id = par_dirid;
288         deh[1].deh_objectid = par_objid;
289         deh[1].deh_state = 0;   /* Endian safe if 0 */
290         put_deh_location(&(deh[1]),
291                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
292         mark_de_visible(&(deh[1]));
293
294         /* copy ".." and "." */
295         memcpy(body + deh_location(&(deh[0])), ".", 1);
296         memcpy(body + deh_location(&(deh[1])), "..", 2);
297 }