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 <linux/uaccess.h>
13
14 extern const struct reiserfs_key MIN_KEY;
15
16 static int reiserfs_readdir(struct file *, struct dir_context *);
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 .iterate_shared = 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 = file_write_and_wait_range(filp, start, end);
38 if (err)
39 return err;
40
41 inode_lock(inode);
42 reiserfs_write_lock(inode->i_sb);
43 err = reiserfs_commit_for_inode(inode);
44 reiserfs_write_unlock(inode->i_sb);
45 inode_unlock(inode);
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 inode * dir,struct reiserfs_de_head * deh)53 static inline bool is_privroot_deh(struct inode *dir, struct reiserfs_de_head *deh)
54 {
55 struct dentry *privroot = REISERFS_SB(dir->i_sb)->priv_root;
56 return (d_really_is_positive(privroot) &&
57 deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid);
58 }
59
reiserfs_readdir_inode(struct inode * inode,struct dir_context * ctx)60 int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx)
61 {
62
63 /* key of current position in the directory (key of directory entry) */
64 struct cpu_key pos_key;
65
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 int depth;
78
79 reiserfs_write_lock(inode->i_sb);
80
81 reiserfs_check_lock_depth(inode->i_sb, "readdir");
82
83 /*
84 * form key for search the next directory entry using
85 * f_pos field of file structure
86 */
87 make_cpu_key(&pos_key, inode, ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
88 next_pos = cpu_key_k_offset(&pos_key);
89
90 path_to_entry.reada = PATH_READA;
91 while (1) {
92 research:
93 /*
94 * search the directory item, containing entry with
95 * specified key
96 */
97 search_res =
98 search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
99 &de);
100 if (search_res == IO_ERROR) {
101 /*
102 * FIXME: we could just skip part of directory
103 * which could not be read
104 */
105 ret = -EIO;
106 goto out;
107 }
108 entry_num = de.de_entry_num;
109 bh = de.de_bh;
110 item_num = de.de_item_num;
111 ih = de.de_ih;
112 store_ih(&tmp_ih, ih);
113
114 /* we must have found item, that is item of this directory, */
115 RFALSE(COMP_SHORT_KEYS(&ih->ih_key, &pos_key),
116 "vs-9000: found item %h does not match to dir we readdir %K",
117 ih, &pos_key);
118 RFALSE(item_num > B_NR_ITEMS(bh) - 1,
119 "vs-9005 item_num == %d, item amount == %d",
120 item_num, B_NR_ITEMS(bh));
121
122 /*
123 * and entry must be not more than number of entries
124 * in the item
125 */
126 RFALSE(ih_entry_count(ih) < entry_num,
127 "vs-9010: entry number is too big %d (%d)",
128 entry_num, ih_entry_count(ih));
129
130 /*
131 * go through all entries in the directory item beginning
132 * from the entry, that has been found
133 */
134 if (search_res == POSITION_FOUND
135 || entry_num < ih_entry_count(ih)) {
136 struct reiserfs_de_head *deh =
137 B_I_DEH(bh, ih) + entry_num;
138
139 for (; entry_num < ih_entry_count(ih);
140 entry_num++, deh++) {
141 int d_reclen;
142 char *d_name;
143 ino_t d_ino;
144 loff_t cur_pos = deh_offset(deh);
145
146 /* it is hidden entry */
147 if (!de_visible(deh))
148 continue;
149 d_reclen = entry_length(bh, ih, entry_num);
150 d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
151
152 if (d_reclen <= 0 ||
153 d_name + d_reclen > bh->b_data + bh->b_size) {
154 /*
155 * There is corrupted data in entry,
156 * We'd better stop here
157 */
158 pathrelse(&path_to_entry);
159 ret = -EIO;
160 goto out;
161 }
162
163 if (!d_name[d_reclen - 1])
164 d_reclen = strlen(d_name);
165
166 /* too big to send back to VFS */
167 if (d_reclen >
168 REISERFS_MAX_NAME(inode->i_sb->
169 s_blocksize)) {
170 continue;
171 }
172
173 /* Ignore the .reiserfs_priv entry */
174 if (is_privroot_deh(inode, deh))
175 continue;
176
177 ctx->pos = deh_offset(deh);
178 d_ino = deh_objectid(deh);
179 if (d_reclen <= 32) {
180 local_buf = small_buf;
181 } else {
182 local_buf = kmalloc(d_reclen,
183 GFP_NOFS);
184 if (!local_buf) {
185 pathrelse(&path_to_entry);
186 ret = -ENOMEM;
187 goto out;
188 }
189 if (item_moved(&tmp_ih, &path_to_entry)) {
190 kfree(local_buf);
191 goto research;
192 }
193 }
194
195 /*
196 * Note, that we copy name to user space via
197 * temporary buffer (local_buf) because
198 * filldir will block if user space buffer is
199 * swapped out. At that time entry can move to
200 * somewhere else
201 */
202 memcpy(local_buf, d_name, d_reclen);
203
204 /*
205 * Since filldir might sleep, we can release
206 * the write lock here for other waiters
207 */
208 depth = reiserfs_write_unlock_nested(inode->i_sb);
209 if (!dir_emit
210 (ctx, local_buf, d_reclen, d_ino,
211 DT_UNKNOWN)) {
212 reiserfs_write_lock_nested(inode->i_sb, depth);
213 if (local_buf != small_buf) {
214 kfree(local_buf);
215 }
216 goto end;
217 }
218 reiserfs_write_lock_nested(inode->i_sb, depth);
219 if (local_buf != small_buf) {
220 kfree(local_buf);
221 }
222
223 /* deh_offset(deh) may be invalid now. */
224 next_pos = cur_pos + 1;
225
226 if (item_moved(&tmp_ih, &path_to_entry)) {
227 set_cpu_key_k_offset(&pos_key,
228 next_pos);
229 goto research;
230 }
231 } /* for */
232 }
233
234 /* end of directory has been reached */
235 if (item_num != B_NR_ITEMS(bh) - 1)
236 goto end;
237
238 /*
239 * item we went through is last item of node. Using right
240 * delimiting key check is it directory end
241 */
242 rkey = get_rkey(&path_to_entry, inode->i_sb);
243 if (!comp_le_keys(rkey, &MIN_KEY)) {
244 /*
245 * set pos_key to key, that is the smallest and greater
246 * that key of the last entry in the item
247 */
248 set_cpu_key_k_offset(&pos_key, next_pos);
249 continue;
250 }
251
252 /* end of directory has been reached */
253 if (COMP_SHORT_KEYS(rkey, &pos_key)) {
254 goto end;
255 }
256
257 /* directory continues in the right neighboring block */
258 set_cpu_key_k_offset(&pos_key,
259 le_key_k_offset(KEY_FORMAT_3_5, rkey));
260
261 } /* while */
262
263 end:
264 ctx->pos = next_pos;
265 pathrelse(&path_to_entry);
266 reiserfs_check_path(&path_to_entry);
267 out:
268 reiserfs_write_unlock(inode->i_sb);
269 return ret;
270 }
271
reiserfs_readdir(struct file * file,struct dir_context * ctx)272 static int reiserfs_readdir(struct file *file, struct dir_context *ctx)
273 {
274 return reiserfs_readdir_inode(file_inode(file), ctx);
275 }
276
277 /*
278 * compose directory item containing "." and ".." entries (entries are
279 * not aligned to 4 byte boundary)
280 */
make_empty_dir_item_v1(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)281 void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
282 __le32 par_dirid, __le32 par_objid)
283 {
284 struct reiserfs_de_head *dot, *dotdot;
285
286 memset(body, 0, EMPTY_DIR_SIZE_V1);
287 dot = (struct reiserfs_de_head *)body;
288 dotdot = dot + 1;
289
290 /* direntry header of "." */
291 put_deh_offset(dot, DOT_OFFSET);
292 /* these two are from make_le_item_head, and are LE */
293 dot->deh_dir_id = dirid;
294 dot->deh_objectid = objid;
295 dot->deh_state = 0; /* Endian safe if 0 */
296 put_deh_location(dot, EMPTY_DIR_SIZE_V1 - strlen("."));
297 mark_de_visible(dot);
298
299 /* direntry header of ".." */
300 put_deh_offset(dotdot, DOT_DOT_OFFSET);
301 /* key of ".." for the root directory */
302 /* these two are from the inode, and are LE */
303 dotdot->deh_dir_id = par_dirid;
304 dotdot->deh_objectid = par_objid;
305 dotdot->deh_state = 0; /* Endian safe if 0 */
306 put_deh_location(dotdot, deh_location(dot) - strlen(".."));
307 mark_de_visible(dotdot);
308
309 /* copy ".." and "." */
310 memcpy(body + deh_location(dot), ".", 1);
311 memcpy(body + deh_location(dotdot), "..", 2);
312 }
313
314 /* compose directory item containing "." and ".." entries */
make_empty_dir_item(char * body,__le32 dirid,__le32 objid,__le32 par_dirid,__le32 par_objid)315 void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
316 __le32 par_dirid, __le32 par_objid)
317 {
318 struct reiserfs_de_head *dot, *dotdot;
319
320 memset(body, 0, EMPTY_DIR_SIZE);
321 dot = (struct reiserfs_de_head *)body;
322 dotdot = dot + 1;
323
324 /* direntry header of "." */
325 put_deh_offset(dot, DOT_OFFSET);
326 /* these two are from make_le_item_head, and are LE */
327 dot->deh_dir_id = dirid;
328 dot->deh_objectid = objid;
329 dot->deh_state = 0; /* Endian safe if 0 */
330 put_deh_location(dot, EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
331 mark_de_visible(dot);
332
333 /* direntry header of ".." */
334 put_deh_offset(dotdot, DOT_DOT_OFFSET);
335 /* key of ".." for the root directory */
336 /* these two are from the inode, and are LE */
337 dotdot->deh_dir_id = par_dirid;
338 dotdot->deh_objectid = par_objid;
339 dotdot->deh_state = 0; /* Endian safe if 0 */
340 put_deh_location(dotdot, deh_location(dot) - ROUND_UP(strlen("..")));
341 mark_de_visible(dotdot);
342
343 /* copy ".." and "." */
344 memcpy(body + deh_location(dot), ".", 1);
345 memcpy(body + deh_location(dotdot), "..", 2);
346 }
347