9aabcc0ccd2d002401e7611a93f5f6b8458136c0
[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/smp_lock.h>
11 #include <linux/buffer_head.h>
12 #include <asm/uaccess.h>
13
14 extern 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         .ioctl = reiserfs_ioctl,
25 };
26
27 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
28                               int datasync)
29 {
30         struct inode *inode = dentry->d_inode;
31         int err;
32         reiserfs_write_lock(inode->i_sb);
33         err = reiserfs_commit_for_inode(inode);
34         reiserfs_write_unlock(inode->i_sb);
35         if (err < 0)
36                 return err;
37         return 0;
38 }
39
40 #define store_ih(where,what) copy_item_head (where, what)
41
42 //
43 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
44 {
45         struct inode *inode = filp->f_dentry->d_inode;
46         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
47         INITIALIZE_PATH(path_to_entry);
48         struct buffer_head *bh;
49         int item_num, entry_num;
50         const struct reiserfs_key *rkey;
51         struct item_head *ih, tmp_ih;
52         int search_res;
53         char *local_buf;
54         loff_t next_pos;
55         char small_buf[32];     /* avoid kmalloc if we can */
56         struct reiserfs_dir_entry de;
57         int ret = 0;
58
59         reiserfs_write_lock(inode->i_sb);
60
61         reiserfs_check_lock_depth(inode->i_sb, "readdir");
62
63         /* form key for search the next directory entry using f_pos field of
64            file structure */
65         make_cpu_key(&pos_key, inode,
66                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
67                      3);
68         next_pos = cpu_key_k_offset(&pos_key);
69
70         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
71
72         path_to_entry.reada = PATH_READA;
73         while (1) {
74               research:
75                 /* search the directory item, containing entry with specified key */
76                 search_res =
77                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
78                                         &de);
79                 if (search_res == IO_ERROR) {
80                         // FIXME: we could just skip part of directory which could
81                         // not be read
82                         ret = -EIO;
83                         goto out;
84                 }
85                 entry_num = de.de_entry_num;
86                 bh = de.de_bh;
87                 item_num = de.de_item_num;
88                 ih = de.de_ih;
89                 store_ih(&tmp_ih, ih);
90
91                 /* we must have found item, that is item of this directory, */
92                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
93                        "vs-9000: found item %h does not match to dir we readdir %K",
94                        ih, &pos_key);
95                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
96                        "vs-9005 item_num == %d, item amount == %d",
97                        item_num, B_NR_ITEMS(bh));
98
99                 /* and entry must be not more than number of entries in the item */
100                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
101                        "vs-9010: entry number is too big %d (%d)",
102                        entry_num, I_ENTRY_COUNT(ih));
103
104                 if (search_res == POSITION_FOUND
105                     || entry_num < I_ENTRY_COUNT(ih)) {
106                         /* go through all entries in the directory item beginning from the entry, that has been found */
107                         struct reiserfs_de_head *deh =
108                             B_I_DEH(bh, ih) + entry_num;
109
110                         for (; entry_num < I_ENTRY_COUNT(ih);
111                              entry_num++, deh++) {
112                                 int d_reclen;
113                                 char *d_name;
114                                 off_t d_off;
115                                 ino_t d_ino;
116
117                                 if (!de_visible(deh))
118                                         /* it is hidden entry */
119                                         continue;
120                                 d_reclen = entry_length(bh, ih, entry_num);
121                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
122                                 if (!d_name[d_reclen - 1])
123                                         d_reclen = strlen(d_name);
124
125                                 if (d_reclen >
126                                     REISERFS_MAX_NAME(inode->i_sb->
127                                                       s_blocksize)) {
128                                         /* too big to send back to VFS */
129                                         continue;
130                                 }
131
132                                 /* Ignore the .reiserfs_priv entry */
133                                 if (reiserfs_xattrs(inode->i_sb) &&
134                                     !old_format_only(inode->i_sb) &&
135                                     filp->f_dentry == inode->i_sb->s_root &&
136                                     REISERFS_SB(inode->i_sb)->priv_root &&
137                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
138                                     && deh_objectid(deh) ==
139                                     le32_to_cpu(INODE_PKEY
140                                                 (REISERFS_SB(inode->i_sb)->
141                                                  priv_root->d_inode)->
142                                                 k_objectid)) {
143                                         continue;
144                                 }
145
146                                 d_off = deh_offset(deh);
147                                 filp->f_pos = d_off;
148                                 d_ino = deh_objectid(deh);
149                                 if (d_reclen <= 32) {
150                                         local_buf = small_buf;
151                                 } else {
152                                         local_buf = kmalloc(d_reclen,
153                                                             GFP_NOFS);
154                                         if (!local_buf) {
155                                                 pathrelse(&path_to_entry);
156                                                 ret = -ENOMEM;
157                                                 goto out;
158                                         }
159                                         if (item_moved(&tmp_ih, &path_to_entry)) {
160                                                 kfree(local_buf);
161                                                 goto research;
162                                         }
163                                 }
164                                 // Note, that we copy name to user space via temporary
165                                 // buffer (local_buf) because filldir will block if
166                                 // user space buffer is swapped out. At that time
167                                 // entry can move to somewhere else
168                                 memcpy(local_buf, d_name, d_reclen);
169                                 if (filldir
170                                     (dirent, local_buf, d_reclen, d_off, d_ino,
171                                      DT_UNKNOWN) < 0) {
172                                         if (local_buf != small_buf) {
173                                                 kfree(local_buf);
174                                         }
175                                         goto end;
176                                 }
177                                 if (local_buf != small_buf) {
178                                         kfree(local_buf);
179                                 }
180                                 // next entry should be looked for with such offset
181                                 next_pos = deh_offset(deh) + 1;
182
183                                 if (item_moved(&tmp_ih, &path_to_entry)) {
184                                         goto research;
185                                 }
186                         }       /* for */
187                 }
188
189                 if (item_num != B_NR_ITEMS(bh) - 1)
190                         // end of directory has been reached
191                         goto end;
192
193                 /* item we went through is last item of node. Using right
194                    delimiting key check is it directory end */
195                 rkey = get_rkey(&path_to_entry, inode->i_sb);
196                 if (!comp_le_keys(rkey, &MIN_KEY)) {
197                         /* set pos_key to key, that is the smallest and greater
198                            that key of the last entry in the item */
199                         set_cpu_key_k_offset(&pos_key, next_pos);
200                         continue;
201                 }
202
203                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
204                         // end of directory has been reached
205                         goto end;
206                 }
207
208                 /* directory continues in the right neighboring block */
209                 set_cpu_key_k_offset(&pos_key,
210                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
211
212         }                       /* while */
213
214       end:
215         filp->f_pos = next_pos;
216         pathrelse(&path_to_entry);
217         reiserfs_check_path(&path_to_entry);
218       out:
219         reiserfs_write_unlock(inode->i_sb);
220         return ret;
221 }
222
223 /* compose directory item containing "." and ".." entries (entries are
224    not aligned to 4 byte boundary) */
225 /* the last four params are LE */
226 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
227                             __le32 par_dirid, __le32 par_objid)
228 {
229         struct reiserfs_de_head *deh;
230
231         memset(body, 0, EMPTY_DIR_SIZE_V1);
232         deh = (struct reiserfs_de_head *)body;
233
234         /* direntry header of "." */
235         put_deh_offset(&(deh[0]), DOT_OFFSET);
236         /* these two are from make_le_item_head, and are are LE */
237         deh[0].deh_dir_id = dirid;
238         deh[0].deh_objectid = objid;
239         deh[0].deh_state = 0;   /* Endian safe if 0 */
240         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
241         mark_de_visible(&(deh[0]));
242
243         /* direntry header of ".." */
244         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
245         /* key of ".." for the root directory */
246         /* these two are from the inode, and are are LE */
247         deh[1].deh_dir_id = par_dirid;
248         deh[1].deh_objectid = par_objid;
249         deh[1].deh_state = 0;   /* Endian safe if 0 */
250         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
251         mark_de_visible(&(deh[1]));
252
253         /* copy ".." and "." */
254         memcpy(body + deh_location(&(deh[0])), ".", 1);
255         memcpy(body + deh_location(&(deh[1])), "..", 2);
256 }
257
258 /* compose directory item containing "." and ".." entries */
259 void make_empty_dir_item(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);
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 - ROUND_UP(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]),
284                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
285         mark_de_visible(&(deh[1]));
286
287         /* copy ".." and "." */
288         memcpy(body + deh_location(&(deh[0])), ".", 1);
289         memcpy(body + deh_location(&(deh[1])), "..", 2);
290 }