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 }
305
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