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