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 <linux/slab.h>
12 #include <asm/uaccess.h>
13
14 extern const 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, int datasync);
18
19 const struct file_operations reiserfs_dir_operations = {
20 .llseek = generic_file_llseek,
21 .read = generic_read_dir,
22 .readdir = reiserfs_readdir,
23 .fsync = reiserfs_dir_fsync,
24 .unlocked_ioctl = reiserfs_ioctl,
25 #ifdef CONFIG_COMPAT
26 .compat_ioctl = reiserfs_compat_ioctl,
27 #endif
28 };
29
reiserfs_dir_fsync(struct file * filp,int datasync)30 static int reiserfs_dir_fsync(struct file *filp, int datasync)
31 {
32 struct inode *inode = filp->f_mapping->host;
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
is_privroot_deh(struct dentry * dir,struct reiserfs_de_head * deh)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 return (dir == dir->d_parent && privroot->d_inode &&
49 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
50 }
51
reiserfs_readdir_dentry(struct dentry * dentry,void * dirent,filldir_t filldir,loff_t * pos)52 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
53 filldir_t filldir, loff_t *pos)
54 {
55 struct inode *inode = dentry->d_inode;
56 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
57 INITIALIZE_PATH(path_to_entry);
58 struct buffer_head *bh;
59 int item_num, entry_num;
60 const struct reiserfs_key *rkey;
61 struct item_head *ih, tmp_ih;
62 int search_res;
63 char *local_buf;
64 loff_t next_pos;
65 char small_buf[32]; /* avoid kmalloc if we can */
66 struct reiserfs_dir_entry de;
67 int ret = 0;
68
69 reiserfs_write_lock(inode->i_sb);
70
71 reiserfs_check_lock_depth(inode->i_sb, "readdir");
72
73 /* form key for search the next directory entry using f_pos field of
74 file structure */
75 make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
76 next_pos = cpu_key_k_offset(&pos_key);
77
78 path_to_entry.reada = PATH_READA;
79 while (1) {
80 research:
81 /* search the directory item, containing entry with specified key */
82 search_res =
83 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
84 &de);
85 if (search_res == IO_ERROR) {
86 // FIXME: we could just skip part of directory which could
87 // not be read
88 ret = -EIO;
89 goto out;
90 }
91 entry_num = de.de_entry_num;
92 bh = de.de_bh;
93 item_num = de.de_item_num;
94 ih = de.de_ih;
95 store_ih(&tmp_ih, ih);
96
97 /* we must have found item, that is item of this directory, */
98 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
99 "vs-9000: found item %h does not match to dir we readdir %K",
100 ih, &pos_key);
101 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
102 "vs-9005 item_num == %d, item amount == %d",
103 item_num, B_NR_ITEMS(bh));
104
105 /* and entry must be not more than number of entries in the item */
106 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
107 "vs-9010: entry number is too big %d (%d)",
108 entry_num, I_ENTRY_COUNT(ih));
109
110 if (search_res == POSITION_FOUND
111 || entry_num < I_ENTRY_COUNT(ih)) {
112 /* go through all entries in the directory item beginning from the entry, that has been found */
113 struct reiserfs_de_head *deh =
114 B_I_DEH(bh, ih) + entry_num;
115
116 for (; entry_num < I_ENTRY_COUNT(ih);
117 entry_num++, deh++) {
118 int d_reclen;
119 char *d_name;
120 off_t d_off;
121 ino_t d_ino;
122
123 if (!de_visible(deh))
124 /* it is hidden entry */
125 continue;
126 d_reclen = entry_length(bh, ih, entry_num);
127 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
128
129 if (d_reclen <= 0 ||
130 d_name + d_reclen > bh->b_data + bh->b_size) {
131 /* There is corrupted data in entry,
132 * We'd better stop here */
133 pathrelse(&path_to_entry);
134 ret = -EIO;
135 goto out;
136 }
137
138 if (!d_name[d_reclen - 1])
139 d_reclen = strlen(d_name);
140
141 if (d_reclen >
142 REISERFS_MAX_NAME(inode->i_sb->
143 s_blocksize)) {
144 /* too big to send back to VFS */
145 continue;
146 }
147
148 /* Ignore the .reiserfs_priv entry */
149 if (is_privroot_deh(dentry, deh))
150 continue;
151
152 d_off = deh_offset(deh);
153 *pos = d_off;
154 d_ino = deh_objectid(deh);
155 if (d_reclen <= 32) {
156 local_buf = small_buf;
157 } else {
158 local_buf = kmalloc(d_reclen,
159 GFP_NOFS);
160 if (!local_buf) {
161 pathrelse(&path_to_entry);
162 ret = -ENOMEM;
163 goto out;
164 }
165 if (item_moved(&tmp_ih, &path_to_entry)) {
166 kfree(local_buf);
167 goto research;
168 }
169 }
170 // Note, that we copy name to user space via temporary
171 // buffer (local_buf) because filldir will block if
172 // user space buffer is swapped out. At that time
173 // entry can move to somewhere else
174 memcpy(local_buf, d_name, d_reclen);
175
176 /*
177 * Since filldir might sleep, we can release
178 * the write lock here for other waiters
179 */
180 reiserfs_write_unlock(inode->i_sb);
181 if (filldir
182 (dirent, local_buf, d_reclen, d_off, d_ino,
183 DT_UNKNOWN) < 0) {
184 reiserfs_write_lock(inode->i_sb);
185 if (local_buf != small_buf) {
186 kfree(local_buf);
187 }
188 goto end;
189 }
190 reiserfs_write_lock(inode->i_sb);
191 if (local_buf != small_buf) {
192 kfree(local_buf);
193 }
194 // next entry should be looked for with such offset
195 next_pos = deh_offset(deh) + 1;
196
197 if (item_moved(&tmp_ih, &path_to_entry)) {
198 goto research;
199 }
200 } /* for */
201 }
202
203 if (item_num != B_NR_ITEMS(bh) - 1)
204 // end of directory has been reached
205 goto end;
206
207 /* item we went through is last item of node. Using right
208 delimiting key check is it directory end */
209 rkey = get_rkey(&path_to_entry, inode->i_sb);
210 if (!comp_le_keys(rkey, &MIN_KEY)) {
211 /* set pos_key to key, that is the smallest and greater
212 that key of the last entry in the item */
213 set_cpu_key_k_offset(&pos_key, next_pos);
214 continue;
215 }
216
217 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
218 // end of directory has been reached
219 goto end;
220 }
221
222 /* directory continues in the right neighboring block */
223 set_cpu_key_k_offset(&pos_key,
224 le_key_k_offset(KEY_FORMAT_3_5, rkey));
225
226 } /* while */
227
228 end:
229 *pos = next_pos;
230 pathrelse(&path_to_entry);
231 reiserfs_check_path(&path_to_entry);
232 out:
233 reiserfs_write_unlock(inode->i_sb);
234 return ret;
235 }
236
reiserfs_readdir(struct file * file,void * dirent,filldir_t filldir)237 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
238 {
239 struct dentry *dentry = file->f_path.dentry;
240 return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
241 }
242
243 /* compose directory item containing "." and ".." entries (entries are
244 not aligned to 4 byte boundary) */
245 /* the last four params are LE */
make_empty_dir_item_v1(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)246 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
247 __le32 par_dirid, __le32 par_objid)
248 {
249 struct reiserfs_de_head *deh;
250
251 memset(body, 0, EMPTY_DIR_SIZE_V1);
252 deh = (struct reiserfs_de_head *)body;
253
254 /* direntry header of "." */
255 put_deh_offset(&(deh[0]), DOT_OFFSET);
256 /* these two are from make_le_item_head, and are are LE */
257 deh[0].deh_dir_id = dirid;
258 deh[0].deh_objectid = objid;
259 deh[0].deh_state = 0; /* Endian safe if 0 */
260 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
261 mark_de_visible(&(deh[0]));
262
263 /* direntry header of ".." */
264 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
265 /* key of ".." for the root directory */
266 /* these two are from the inode, and are are LE */
267 deh[1].deh_dir_id = par_dirid;
268 deh[1].deh_objectid = par_objid;
269 deh[1].deh_state = 0; /* Endian safe if 0 */
270 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
271 mark_de_visible(&(deh[1]));
272
273 /* copy ".." and "." */
274 memcpy(body + deh_location(&(deh[0])), ".", 1);
275 memcpy(body + deh_location(&(deh[1])), "..", 2);
276 }
277
278 /* compose directory item containing "." and ".." entries */
make_empty_dir_item(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)279 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
280 __le32 par_dirid, __le32 par_objid)
281 {
282 struct reiserfs_de_head *deh;
283
284 memset(body, 0, EMPTY_DIR_SIZE);
285 deh = (struct reiserfs_de_head *)body;
286
287 /* direntry header of "." */
288 put_deh_offset(&(deh[0]), DOT_OFFSET);
289 /* these two are from make_le_item_head, and are are LE */
290 deh[0].deh_dir_id = dirid;
291 deh[0].deh_objectid = objid;
292 deh[0].deh_state = 0; /* Endian safe if 0 */
293 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
294 mark_de_visible(&(deh[0]));
295
296 /* direntry header of ".." */
297 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
298 /* key of ".." for the root directory */
299 /* these two are from the inode, and are are LE */
300 deh[1].deh_dir_id = par_dirid;
301 deh[1].deh_objectid = par_objid;
302 deh[1].deh_state = 0; /* Endian safe if 0 */
303 put_deh_location(&(deh[1]),
304 deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
305 mark_de_visible(&(deh[1]));
306
307 /* copy ".." and "." */
308 memcpy(body + deh_location(&(deh[0])), ".", 1);
309 memcpy(body + deh_location(&(deh[1])), "..", 2);
310 }
311