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 "reiserfs.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, loff_t start, loff_t end,
18 int datasync);
19
20 const struct file_operations reiserfs_dir_operations = {
21 .llseek = generic_file_llseek,
22 .read = generic_read_dir,
23 .readdir = reiserfs_readdir,
24 .fsync = reiserfs_dir_fsync,
25 .unlocked_ioctl = reiserfs_ioctl,
26 #ifdef CONFIG_COMPAT
27 .compat_ioctl = reiserfs_compat_ioctl,
28 #endif
29 };
30
reiserfs_dir_fsync(struct file * filp,loff_t start,loff_t end,int datasync)31 static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
32 int datasync)
33 {
34 struct inode *inode = filp->f_mapping->host;
35 int err;
36
37 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
38 if (err)
39 return err;
40
41 mutex_lock(&inode->i_mutex);
42 reiserfs_write_lock(inode->i_sb);
43 err = reiserfs_commit_for_inode(inode);
44 reiserfs_write_unlock(inode->i_sb);
45 mutex_unlock(&inode->i_mutex);
46 if (err < 0)
47 return err;
48 return 0;
49 }
50
51 #define store_ih(where,what) copy_item_head (where, what)
52
is_privroot_deh(struct dentry * dir,struct reiserfs_de_head * deh)53 static inline bool is_privroot_deh(struct dentry *dir,
54 struct reiserfs_de_head *deh)
55 {
56 struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
57 return (dir == dir->d_parent && privroot->d_inode &&
58 deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
59 }
60
reiserfs_readdir_dentry(struct dentry * dentry,void * dirent,filldir_t filldir,loff_t * pos)61 int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
62 filldir_t filldir, loff_t *pos)
63 {
64 struct inode *inode = dentry->d_inode;
65 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
66 INITIALIZE_PATH(path_to_entry);
67 struct buffer_head *bh;
68 int item_num, entry_num;
69 const struct reiserfs_key *rkey;
70 struct item_head *ih, tmp_ih;
71 int search_res;
72 char *local_buf;
73 loff_t next_pos;
74 char small_buf[32]; /* avoid kmalloc if we can */
75 struct reiserfs_dir_entry de;
76 int ret = 0;
77
78 reiserfs_write_lock(inode->i_sb);
79
80 reiserfs_check_lock_depth(inode->i_sb, "readdir");
81
82 /* form key for search the next directory entry using f_pos field of
83 file structure */
84 make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
85 next_pos = cpu_key_k_offset(&pos_key);
86
87 path_to_entry.reada = PATH_READA;
88 while (1) {
89 research:
90 /* search the directory item, containing entry with specified key */
91 search_res =
92 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
93 &de);
94 if (search_res == IO_ERROR) {
95 // FIXME: we could just skip part of directory which could
96 // not be read
97 ret = -EIO;
98 goto out;
99 }
100 entry_num = de.de_entry_num;
101 bh = de.de_bh;
102 item_num = de.de_item_num;
103 ih = de.de_ih;
104 store_ih(&tmp_ih, ih);
105
106 /* we must have found item, that is item of this directory, */
107 RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
108 "vs-9000: found item %h does not match to dir we readdir %K",
109 ih, &pos_key);
110 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
111 "vs-9005 item_num == %d, item amount == %d",
112 item_num, B_NR_ITEMS(bh));
113
114 /* and entry must be not more than number of entries in the item */
115 RFALSE(I_ENTRY_COUNT(ih) < entry_num,
116 "vs-9010: entry number is too big %d (%d)",
117 entry_num, I_ENTRY_COUNT(ih));
118
119 if (search_res == POSITION_FOUND
120 || entry_num < I_ENTRY_COUNT(ih)) {
121 /* go through all entries in the directory item beginning from the entry, that has been found */
122 struct reiserfs_de_head *deh =
123 B_I_DEH(bh, ih) + entry_num;
124
125 for (; entry_num < I_ENTRY_COUNT(ih);
126 entry_num++, deh++) {
127 int d_reclen;
128 char *d_name;
129 off_t d_off;
130 ino_t d_ino;
131 loff_t cur_pos = deh_offset(deh);
132
133 if (!de_visible(deh))
134 /* it is hidden entry */
135 continue;
136 d_reclen = entry_length(bh, ih, entry_num);
137 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
138
139 if (d_reclen <= 0 ||
140 d_name + d_reclen > bh->b_data + bh->b_size) {
141 /* There is corrupted data in entry,
142 * We'd better stop here */
143 pathrelse(&path_to_entry);
144 ret = -EIO;
145 goto out;
146 }
147
148 if (!d_name[d_reclen - 1])
149 d_reclen = strlen(d_name);
150
151 if (d_reclen >
152 REISERFS_MAX_NAME(inode->i_sb->
153 s_blocksize)) {
154 /* too big to send back to VFS */
155 continue;
156 }
157
158 /* Ignore the .reiserfs_priv entry */
159 if (is_privroot_deh(dentry, deh))
160 continue;
161
162 d_off = deh_offset(deh);
163 *pos = d_off;
164 d_ino = deh_objectid(deh);
165 if (d_reclen <= 32) {
166 local_buf = small_buf;
167 } else {
168 local_buf = kmalloc(d_reclen,
169 GFP_NOFS);
170 if (!local_buf) {
171 pathrelse(&path_to_entry);
172 ret = -ENOMEM;
173 goto out;
174 }
175 if (item_moved(&tmp_ih, &path_to_entry)) {
176 kfree(local_buf);
177 goto research;
178 }
179 }
180 // Note, that we copy name to user space via temporary
181 // buffer (local_buf) because filldir will block if
182 // user space buffer is swapped out. At that time
183 // entry can move to somewhere else
184 memcpy(local_buf, d_name, d_reclen);
185
186 /*
187 * Since filldir might sleep, we can release
188 * the write lock here for other waiters
189 */
190 reiserfs_write_unlock(inode->i_sb);
191 if (filldir
192 (dirent, local_buf, d_reclen, d_off, d_ino,
193 DT_UNKNOWN) < 0) {
194 reiserfs_write_lock(inode->i_sb);
195 if (local_buf != small_buf) {
196 kfree(local_buf);
197 }
198 goto end;
199 }
200 reiserfs_write_lock(inode->i_sb);
201 if (local_buf != small_buf) {
202 kfree(local_buf);
203 }
204
205 /* deh_offset(deh) may be invalid now. */
206 next_pos = cur_pos + 1;
207
208 if (item_moved(&tmp_ih, &path_to_entry)) {
209 goto research;
210 }
211 } /* for */
212 }
213
214 if (item_num != B_NR_ITEMS(bh) - 1)
215 // end of directory has been reached
216 goto end;
217
218 /* item we went through is last item of node. Using right
219 delimiting key check is it directory end */
220 rkey = get_rkey(&path_to_entry, inode->i_sb);
221 if (!comp_le_keys(rkey, &MIN_KEY)) {
222 /* set pos_key to key, that is the smallest and greater
223 that key of the last entry in the item */
224 set_cpu_key_k_offset(&pos_key, next_pos);
225 continue;
226 }
227
228 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
229 // end of directory has been reached
230 goto end;
231 }
232
233 /* directory continues in the right neighboring block */
234 set_cpu_key_k_offset(&pos_key,
235 le_key_k_offset(KEY_FORMAT_3_5, rkey));
236
237 } /* while */
238
239 end:
240 *pos = next_pos;
241 pathrelse(&path_to_entry);
242 reiserfs_check_path(&path_to_entry);
243 out:
244 reiserfs_write_unlock(inode->i_sb);
245 return ret;
246 }
247
reiserfs_readdir(struct file * file,void * dirent,filldir_t filldir)248 static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
249 {
250 struct dentry *dentry = file->f_path.dentry;
251 return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
252 }
253
254 /* compose directory item containing "." and ".." entries (entries are
255 not aligned to 4 byte boundary) */
256 /* the last four params are LE */
make_empty_dir_item_v1(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)257 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
258 __le32 par_dirid, __le32 par_objid)
259 {
260 struct reiserfs_de_head *deh;
261
262 memset(body, 0, EMPTY_DIR_SIZE_V1);
263 deh = (struct reiserfs_de_head *)body;
264
265 /* direntry header of "." */
266 put_deh_offset(&(deh[0]), DOT_OFFSET);
267 /* these two are from make_le_item_head, and are are LE */
268 deh[0].deh_dir_id = dirid;
269 deh[0].deh_objectid = objid;
270 deh[0].deh_state = 0; /* Endian safe if 0 */
271 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
272 mark_de_visible(&(deh[0]));
273
274 /* direntry header of ".." */
275 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
276 /* key of ".." for the root directory */
277 /* these two are from the inode, and are are LE */
278 deh[1].deh_dir_id = par_dirid;
279 deh[1].deh_objectid = par_objid;
280 deh[1].deh_state = 0; /* Endian safe if 0 */
281 put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
282 mark_de_visible(&(deh[1]));
283
284 /* copy ".." and "." */
285 memcpy(body + deh_location(&(deh[0])), ".", 1);
286 memcpy(body + deh_location(&(deh[1])), "..", 2);
287 }
288
289 /* compose directory item containing "." and ".." entries */
make_empty_dir_item(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)290 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
291 __le32 par_dirid, __le32 par_objid)
292 {
293 struct reiserfs_de_head *deh;
294
295 memset(body, 0, EMPTY_DIR_SIZE);
296 deh = (struct reiserfs_de_head *)body;
297
298 /* direntry header of "." */
299 put_deh_offset(&(deh[0]), DOT_OFFSET);
300 /* these two are from make_le_item_head, and are are LE */
301 deh[0].deh_dir_id = dirid;
302 deh[0].deh_objectid = objid;
303 deh[0].deh_state = 0; /* Endian safe if 0 */
304 put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
305 mark_de_visible(&(deh[0]));
306
307 /* direntry header of ".." */
308 put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
309 /* key of ".." for the root directory */
310 /* these two are from the inode, and are are LE */
311 deh[1].deh_dir_id = par_dirid;
312 deh[1].deh_objectid = par_objid;
313 deh[1].deh_state = 0; /* Endian safe if 0 */
314 put_deh_location(&(deh[1]),
315 deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
316 mark_de_visible(&(deh[1]));
317
318 /* copy ".." and "." */
319 memcpy(body + deh_location(&(deh[0])), ".", 1);
320 memcpy(body + deh_location(&(deh[1])), "..", 2);
321 }
322