9c23fee3bae9b678d4d3cd6bbca538e07aa3599d
[sfrench/cifs-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 <asm/uaccess.h>
12
13 extern struct reiserfs_key MIN_KEY;
14
15 static int reiserfs_readdir(struct file *, void *, filldir_t);
16 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
17                               int datasync);
18
19 const struct file_operations reiserfs_dir_operations = {
20         .read = generic_read_dir,
21         .readdir = reiserfs_readdir,
22         .fsync = reiserfs_dir_fsync,
23         .ioctl = reiserfs_ioctl,
24 #ifdef CONFIG_COMPAT
25         .compat_ioctl = reiserfs_compat_ioctl,
26 #endif
27 };
28
29 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
30                               int datasync)
31 {
32         struct inode *inode = dentry->d_inode;
33         int err;
34         reiserfs_write_lock(inode->i_sb);
35         err = reiserfs_commit_for_inode(inode);
36         reiserfs_write_unlock(inode->i_sb);
37         if (err < 0)
38                 return err;
39         return 0;
40 }
41
42 #define store_ih(where,what) copy_item_head (where, what)
43
44 //
45 static int reiserfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
46 {
47         struct inode *inode = filp->f_path.dentry->d_inode;
48         struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
49         INITIALIZE_PATH(path_to_entry);
50         struct buffer_head *bh;
51         int item_num, entry_num;
52         const struct reiserfs_key *rkey;
53         struct item_head *ih, tmp_ih;
54         int search_res;
55         char *local_buf;
56         loff_t next_pos;
57         char small_buf[32];     /* avoid kmalloc if we can */
58         struct reiserfs_dir_entry de;
59         int ret = 0;
60
61         reiserfs_write_lock(inode->i_sb);
62
63         reiserfs_check_lock_depth(inode->i_sb, "readdir");
64
65         /* form key for search the next directory entry using f_pos field of
66            file structure */
67         make_cpu_key(&pos_key, inode,
68                      (filp->f_pos) ? (filp->f_pos) : DOT_OFFSET, TYPE_DIRENTRY,
69                      3);
70         next_pos = cpu_key_k_offset(&pos_key);
71
72         /*  reiserfs_warning (inode->i_sb, "reiserfs_readdir 1: f_pos = %Ld", filp->f_pos); */
73
74         path_to_entry.reada = PATH_READA;
75         while (1) {
76               research:
77                 /* search the directory item, containing entry with specified key */
78                 search_res =
79                     search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
80                                         &de);
81                 if (search_res == IO_ERROR) {
82                         // FIXME: we could just skip part of directory which could
83                         // not be read
84                         ret = -EIO;
85                         goto out;
86                 }
87                 entry_num = de.de_entry_num;
88                 bh = de.de_bh;
89                 item_num = de.de_item_num;
90                 ih = de.de_ih;
91                 store_ih(&tmp_ih, ih);
92
93                 /* we must have found item, that is item of this directory, */
94                 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
95                        "vs-9000: found item %h does not match to dir we readdir %K",
96                        ih, &pos_key);
97                 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
98                        "vs-9005 item_num == %d, item amount == %d",
99                        item_num, B_NR_ITEMS(bh));
100
101                 /* and entry must be not more than number of entries in the item */
102                 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
103                        "vs-9010: entry number is too big %d (%d)",
104                        entry_num, I_ENTRY_COUNT(ih));
105
106                 if (search_res == POSITION_FOUND
107                     || entry_num < I_ENTRY_COUNT(ih)) {
108                         /* go through all entries in the directory item beginning from the entry, that has been found */
109                         struct reiserfs_de_head *deh =
110                             B_I_DEH(bh, ih) + entry_num;
111
112                         for (; entry_num < I_ENTRY_COUNT(ih);
113                              entry_num++, deh++) {
114                                 int d_reclen;
115                                 char *d_name;
116                                 off_t d_off;
117                                 ino_t d_ino;
118
119                                 if (!de_visible(deh))
120                                         /* it is hidden entry */
121                                         continue;
122                                 d_reclen = entry_length(bh, ih, entry_num);
123                                 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
124                                 if (!d_name[d_reclen - 1])
125                                         d_reclen = strlen(d_name);
126
127                                 if (d_reclen >
128                                     REISERFS_MAX_NAME(inode->i_sb->
129                                                       s_blocksize)) {
130                                         /* too big to send back to VFS */
131                                         continue;
132                                 }
133
134                                 /* Ignore the .reiserfs_priv entry */
135                                 if (reiserfs_xattrs(inode->i_sb) &&
136                                     !old_format_only(inode->i_sb) &&
137                                     filp->f_path.dentry == inode->i_sb->s_root &&
138                                     REISERFS_SB(inode->i_sb)->priv_root &&
139                                     REISERFS_SB(inode->i_sb)->priv_root->d_inode
140                                     && deh_objectid(deh) ==
141                                     le32_to_cpu(INODE_PKEY
142                                                 (REISERFS_SB(inode->i_sb)->
143                                                  priv_root->d_inode)->
144                                                 k_objectid)) {
145                                         continue;
146                                 }
147
148                                 d_off = deh_offset(deh);
149                                 filp->f_pos = d_off;
150                                 d_ino = deh_objectid(deh);
151                                 if (d_reclen <= 32) {
152                                         local_buf = small_buf;
153                                 } else {
154                                         local_buf = kmalloc(d_reclen,
155                                                             GFP_NOFS);
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                                                 kfree(local_buf);
163                                                 goto research;
164                                         }
165                                 }
166                                 // Note, that we copy name to user space via temporary
167                                 // buffer (local_buf) because filldir will block if
168                                 // user space buffer is swapped out. At that time
169                                 // entry can move to somewhere else
170                                 memcpy(local_buf, d_name, d_reclen);
171                                 if (filldir
172                                     (dirent, local_buf, d_reclen, d_off, d_ino,
173                                      DT_UNKNOWN) < 0) {
174                                         if (local_buf != small_buf) {
175                                                 kfree(local_buf);
176                                         }
177                                         goto end;
178                                 }
179                                 if (local_buf != small_buf) {
180                                         kfree(local_buf);
181                                 }
182                                 // next entry should be looked for with such offset
183                                 next_pos = deh_offset(deh) + 1;
184
185                                 if (item_moved(&tmp_ih, &path_to_entry)) {
186                                         goto research;
187                                 }
188                         }       /* for */
189                 }
190
191                 if (item_num != B_NR_ITEMS(bh) - 1)
192                         // end of directory has been reached
193                         goto end;
194
195                 /* item we went through is last item of node. Using right
196                    delimiting key check is it directory end */
197                 rkey = get_rkey(&path_to_entry, inode->i_sb);
198                 if (!comp_le_keys(rkey, &MIN_KEY)) {
199                         /* set pos_key to key, that is the smallest and greater
200                            that key of the last entry in the item */
201                         set_cpu_key_k_offset(&pos_key, next_pos);
202                         continue;
203                 }
204
205                 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
206                         // end of directory has been reached
207                         goto end;
208                 }
209
210                 /* directory continues in the right neighboring block */
211                 set_cpu_key_k_offset(&pos_key,
212                                      le_key_k_offset(KEY_FORMAT_3_5, rkey));
213
214         }                       /* while */
215
216       end:
217         filp->f_pos = next_pos;
218         pathrelse(&path_to_entry);
219         reiserfs_check_path(&path_to_entry);
220       out:
221         reiserfs_write_unlock(inode->i_sb);
222         return ret;
223 }
224
225 /* compose directory item containing "." and ".." entries (entries are
226    not aligned to 4 byte boundary) */
227 /* the last four params are LE */
228 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
229                             __le32 par_dirid, __le32 par_objid)
230 {
231         struct reiserfs_de_head *deh;
232
233         memset(body, 0, EMPTY_DIR_SIZE_V1);
234         deh = (struct reiserfs_de_head *)body;
235
236         /* direntry header of "." */
237         put_deh_offset(&(deh[0]), DOT_OFFSET);
238         /* these two are from make_le_item_head, and are are LE */
239         deh[0].deh_dir_id = dirid;
240         deh[0].deh_objectid = objid;
241         deh[0].deh_state = 0;   /* Endian safe if 0 */
242         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
243         mark_de_visible(&(deh[0]));
244
245         /* direntry header of ".." */
246         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
247         /* key of ".." for the root directory */
248         /* these two are from the inode, and are are LE */
249         deh[1].deh_dir_id = par_dirid;
250         deh[1].deh_objectid = par_objid;
251         deh[1].deh_state = 0;   /* Endian safe if 0 */
252         put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
253         mark_de_visible(&(deh[1]));
254
255         /* copy ".." and "." */
256         memcpy(body + deh_location(&(deh[0])), ".", 1);
257         memcpy(body + deh_location(&(deh[1])), "..", 2);
258 }
259
260 /* compose directory item containing "." and ".." entries */
261 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
262                          __le32 par_dirid, __le32 par_objid)
263 {
264         struct reiserfs_de_head *deh;
265
266         memset(body, 0, EMPTY_DIR_SIZE);
267         deh = (struct reiserfs_de_head *)body;
268
269         /* direntry header of "." */
270         put_deh_offset(&(deh[0]), DOT_OFFSET);
271         /* these two are from make_le_item_head, and are are LE */
272         deh[0].deh_dir_id = dirid;
273         deh[0].deh_objectid = objid;
274         deh[0].deh_state = 0;   /* Endian safe if 0 */
275         put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
276         mark_de_visible(&(deh[0]));
277
278         /* direntry header of ".." */
279         put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
280         /* key of ".." for the root directory */
281         /* these two are from the inode, and are are LE */
282         deh[1].deh_dir_id = par_dirid;
283         deh[1].deh_objectid = par_objid;
284         deh[1].deh_state = 0;   /* Endian safe if 0 */
285         put_deh_location(&(deh[1]),
286                          deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
287         mark_de_visible(&(deh[1]));
288
289         /* copy ".." and "." */
290         memcpy(body + deh_location(&(deh[0])), ".", 1);
291         memcpy(body + deh_location(&(deh[1])), "..", 2);
292 }