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 | |
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(file: filp, start, end); |
38 | if (err) |
39 | return err; |
40 | |
41 | inode_lock(inode); |
42 | reiserfs_write_lock(s: inode->i_sb); |
43 | err = reiserfs_commit_for_inode(inode); |
44 | reiserfs_write_unlock(s: 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 | |
53 | static inline bool is_privroot_deh(struct inode *dir, struct reiserfs_de_head *deh) |
54 | { |
55 | struct dentry *privroot = REISERFS_SB(sb: dir->i_sb)->priv_root; |
56 | return (d_really_is_positive(dentry: privroot) && |
57 | deh->deh_objectid == INODE_PKEY(d_inode(privroot))->k_objectid); |
58 | } |
59 | |
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(s: inode->i_sb); |
80 | |
81 | reiserfs_check_lock_depth(s: inode->i_sb, caller: "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(cpu_key: &pos_key, inode, offset: ctx->pos ?: DOT_OFFSET, TYPE_DIRENTRY, key_length: 3); |
88 | next_pos = cpu_key_k_offset(key: &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(sb: inode->i_sb, key: &pos_key, path: &path_to_entry, |
99 | de: &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, pos_in_item: 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(search_path: &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(dir: 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(size: d_reclen, |
183 | GFP_NOFS); |
184 | if (!local_buf) { |
185 | pathrelse(search_path: &path_to_entry); |
186 | ret = -ENOMEM; |
187 | goto out; |
188 | } |
189 | if (item_moved(&tmp_ih, &path_to_entry)) { |
190 | kfree(objp: 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(s: inode->i_sb); |
209 | if (!dir_emit |
210 | (ctx, name: local_buf, namelen: d_reclen, ino: d_ino, |
211 | DT_UNKNOWN)) { |
212 | reiserfs_write_lock_nested(s: inode->i_sb, depth); |
213 | if (local_buf != small_buf) { |
214 | kfree(objp: local_buf); |
215 | } |
216 | goto end; |
217 | } |
218 | reiserfs_write_lock_nested(s: inode->i_sb, depth); |
219 | if (local_buf != small_buf) { |
220 | kfree(objp: 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(key: &pos_key, |
228 | offset: 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(chk_path: &path_to_entry, sb: 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(key: &pos_key, offset: next_pos); |
249 | continue; |
250 | } |
251 | |
252 | /* end of directory has been reached */ |
253 | if (COMP_SHORT_KEYS(le_key: rkey, cpu_key: &pos_key)) { |
254 | goto end; |
255 | } |
256 | |
257 | /* directory continues in the right neighboring block */ |
258 | set_cpu_key_k_offset(key: &pos_key, |
259 | offset: le_key_k_offset(KEY_FORMAT_3_5, key: rkey)); |
260 | |
261 | } /* while */ |
262 | |
263 | end: |
264 | ctx->pos = next_pos; |
265 | pathrelse(search_path: &path_to_entry); |
266 | reiserfs_check_path(p: &path_to_entry); |
267 | out: |
268 | reiserfs_write_unlock(s: inode->i_sb); |
269 | return ret; |
270 | } |
271 | |
272 | static int reiserfs_readdir(struct file *file, struct dir_context *ctx) |
273 | { |
274 | return reiserfs_readdir_inode(inode: file_inode(f: file), ctx); |
275 | } |
276 | |
277 | /* |
278 | * compose directory item containing "." and ".." entries (entries are |
279 | * not aligned to 4 byte boundary) |
280 | */ |
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 */ |
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 | |