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