diff options
Diffstat (limited to 'fs/quota_tree.c')
-rw-r--r-- | fs/quota_tree.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/fs/quota_tree.c b/fs/quota_tree.c new file mode 100644 index 000000000000..953404c95b17 --- /dev/null +++ b/fs/quota_tree.c | |||
@@ -0,0 +1,645 @@ | |||
1 | /* | ||
2 | * vfsv0 quota IO operations on file | ||
3 | */ | ||
4 | |||
5 | #include <linux/errno.h> | ||
6 | #include <linux/fs.h> | ||
7 | #include <linux/mount.h> | ||
8 | #include <linux/dqblk_v2.h> | ||
9 | #include <linux/kernel.h> | ||
10 | #include <linux/init.h> | ||
11 | #include <linux/module.h> | ||
12 | #include <linux/slab.h> | ||
13 | #include <linux/quotaops.h> | ||
14 | |||
15 | #include <asm/byteorder.h> | ||
16 | |||
17 | #include "quota_tree.h" | ||
18 | |||
19 | MODULE_AUTHOR("Jan Kara"); | ||
20 | MODULE_DESCRIPTION("Quota trie support"); | ||
21 | MODULE_LICENSE("GPL"); | ||
22 | |||
23 | #define __QUOTA_QT_PARANOIA | ||
24 | |||
25 | typedef char *dqbuf_t; | ||
26 | |||
27 | static int get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth) | ||
28 | { | ||
29 | unsigned int epb = info->dqi_usable_bs >> 2; | ||
30 | |||
31 | depth = info->dqi_qtree_depth - depth - 1; | ||
32 | while (depth--) | ||
33 | id /= epb; | ||
34 | return id % epb; | ||
35 | } | ||
36 | |||
37 | /* Number of entries in one blocks */ | ||
38 | static inline int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info) | ||
39 | { | ||
40 | return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader)) | ||
41 | / info->dqi_entry_size; | ||
42 | } | ||
43 | |||
44 | static dqbuf_t getdqbuf(size_t size) | ||
45 | { | ||
46 | dqbuf_t buf = kmalloc(size, GFP_NOFS); | ||
47 | if (!buf) | ||
48 | printk(KERN_WARNING "VFS: Not enough memory for quota buffers.\n"); | ||
49 | return buf; | ||
50 | } | ||
51 | |||
52 | static inline void freedqbuf(dqbuf_t buf) | ||
53 | { | ||
54 | kfree(buf); | ||
55 | } | ||
56 | |||
57 | static inline ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, dqbuf_t buf) | ||
58 | { | ||
59 | struct super_block *sb = info->dqi_sb; | ||
60 | |||
61 | memset(buf, 0, info->dqi_usable_bs); | ||
62 | return sb->s_op->quota_read(sb, info->dqi_type, (char *)buf, | ||
63 | info->dqi_usable_bs, blk << info->dqi_blocksize_bits); | ||
64 | } | ||
65 | |||
66 | static inline ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, dqbuf_t buf) | ||
67 | { | ||
68 | struct super_block *sb = info->dqi_sb; | ||
69 | |||
70 | return sb->s_op->quota_write(sb, info->dqi_type, (char *)buf, | ||
71 | info->dqi_usable_bs, blk << info->dqi_blocksize_bits); | ||
72 | } | ||
73 | |||
74 | /* Remove empty block from list and return it */ | ||
75 | static int get_free_dqblk(struct qtree_mem_dqinfo *info) | ||
76 | { | ||
77 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
78 | struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf; | ||
79 | int ret, blk; | ||
80 | |||
81 | if (!buf) | ||
82 | return -ENOMEM; | ||
83 | if (info->dqi_free_blk) { | ||
84 | blk = info->dqi_free_blk; | ||
85 | ret = read_blk(info, blk, buf); | ||
86 | if (ret < 0) | ||
87 | goto out_buf; | ||
88 | info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free); | ||
89 | } | ||
90 | else { | ||
91 | memset(buf, 0, info->dqi_usable_bs); | ||
92 | /* Assure block allocation... */ | ||
93 | ret = write_blk(info, info->dqi_blocks, buf); | ||
94 | if (ret < 0) | ||
95 | goto out_buf; | ||
96 | blk = info->dqi_blocks++; | ||
97 | } | ||
98 | mark_info_dirty(info->dqi_sb, info->dqi_type); | ||
99 | ret = blk; | ||
100 | out_buf: | ||
101 | freedqbuf(buf); | ||
102 | return ret; | ||
103 | } | ||
104 | |||
105 | /* Insert empty block to the list */ | ||
106 | static int put_free_dqblk(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk) | ||
107 | { | ||
108 | struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf; | ||
109 | int err; | ||
110 | |||
111 | dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk); | ||
112 | dh->dqdh_prev_free = cpu_to_le32(0); | ||
113 | dh->dqdh_entries = cpu_to_le16(0); | ||
114 | err = write_blk(info, blk, buf); | ||
115 | if (err < 0) | ||
116 | return err; | ||
117 | info->dqi_free_blk = blk; | ||
118 | mark_info_dirty(info->dqi_sb, info->dqi_type); | ||
119 | return 0; | ||
120 | } | ||
121 | |||
122 | /* Remove given block from the list of blocks with free entries */ | ||
123 | static int remove_free_dqentry(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk) | ||
124 | { | ||
125 | dqbuf_t tmpbuf = getdqbuf(info->dqi_usable_bs); | ||
126 | struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf; | ||
127 | uint nextblk = le32_to_cpu(dh->dqdh_next_free); | ||
128 | uint prevblk = le32_to_cpu(dh->dqdh_prev_free); | ||
129 | int err; | ||
130 | |||
131 | if (!tmpbuf) | ||
132 | return -ENOMEM; | ||
133 | if (nextblk) { | ||
134 | err = read_blk(info, nextblk, tmpbuf); | ||
135 | if (err < 0) | ||
136 | goto out_buf; | ||
137 | ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = | ||
138 | dh->dqdh_prev_free; | ||
139 | err = write_blk(info, nextblk, tmpbuf); | ||
140 | if (err < 0) | ||
141 | goto out_buf; | ||
142 | } | ||
143 | if (prevblk) { | ||
144 | err = read_blk(info, prevblk, tmpbuf); | ||
145 | if (err < 0) | ||
146 | goto out_buf; | ||
147 | ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free = | ||
148 | dh->dqdh_next_free; | ||
149 | err = write_blk(info, prevblk, tmpbuf); | ||
150 | if (err < 0) | ||
151 | goto out_buf; | ||
152 | } else { | ||
153 | info->dqi_free_entry = nextblk; | ||
154 | mark_info_dirty(info->dqi_sb, info->dqi_type); | ||
155 | } | ||
156 | freedqbuf(tmpbuf); | ||
157 | dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0); | ||
158 | /* No matter whether write succeeds block is out of list */ | ||
159 | if (write_blk(info, blk, buf) < 0) | ||
160 | printk(KERN_ERR "VFS: Can't write block (%u) with free entries.\n", blk); | ||
161 | return 0; | ||
162 | out_buf: | ||
163 | freedqbuf(tmpbuf); | ||
164 | return err; | ||
165 | } | ||
166 | |||
167 | /* Insert given block to the beginning of list with free entries */ | ||
168 | static int insert_free_dqentry(struct qtree_mem_dqinfo *info, dqbuf_t buf, uint blk) | ||
169 | { | ||
170 | dqbuf_t tmpbuf = getdqbuf(info->dqi_usable_bs); | ||
171 | struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf; | ||
172 | int err; | ||
173 | |||
174 | if (!tmpbuf) | ||
175 | return -ENOMEM; | ||
176 | dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry); | ||
177 | dh->dqdh_prev_free = cpu_to_le32(0); | ||
178 | err = write_blk(info, blk, buf); | ||
179 | if (err < 0) | ||
180 | goto out_buf; | ||
181 | if (info->dqi_free_entry) { | ||
182 | err = read_blk(info, info->dqi_free_entry, tmpbuf); | ||
183 | if (err < 0) | ||
184 | goto out_buf; | ||
185 | ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free = | ||
186 | cpu_to_le32(blk); | ||
187 | err = write_blk(info, info->dqi_free_entry, tmpbuf); | ||
188 | if (err < 0) | ||
189 | goto out_buf; | ||
190 | } | ||
191 | freedqbuf(tmpbuf); | ||
192 | info->dqi_free_entry = blk; | ||
193 | mark_info_dirty(info->dqi_sb, info->dqi_type); | ||
194 | return 0; | ||
195 | out_buf: | ||
196 | freedqbuf(tmpbuf); | ||
197 | return err; | ||
198 | } | ||
199 | |||
200 | /* Is the entry in the block free? */ | ||
201 | int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk) | ||
202 | { | ||
203 | int i; | ||
204 | |||
205 | for (i = 0; i < info->dqi_entry_size; i++) | ||
206 | if (disk[i]) | ||
207 | return 0; | ||
208 | return 1; | ||
209 | } | ||
210 | EXPORT_SYMBOL(qtree_entry_unused); | ||
211 | |||
212 | /* Find space for dquot */ | ||
213 | static uint find_free_dqentry(struct qtree_mem_dqinfo *info, | ||
214 | struct dquot *dquot, int *err) | ||
215 | { | ||
216 | uint blk, i; | ||
217 | struct qt_disk_dqdbheader *dh; | ||
218 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
219 | char *ddquot; | ||
220 | |||
221 | *err = 0; | ||
222 | if (!buf) { | ||
223 | *err = -ENOMEM; | ||
224 | return 0; | ||
225 | } | ||
226 | dh = (struct qt_disk_dqdbheader *)buf; | ||
227 | if (info->dqi_free_entry) { | ||
228 | blk = info->dqi_free_entry; | ||
229 | *err = read_blk(info, blk, buf); | ||
230 | if (*err < 0) | ||
231 | goto out_buf; | ||
232 | } else { | ||
233 | blk = get_free_dqblk(info); | ||
234 | if ((int)blk < 0) { | ||
235 | *err = blk; | ||
236 | freedqbuf(buf); | ||
237 | return 0; | ||
238 | } | ||
239 | memset(buf, 0, info->dqi_usable_bs); | ||
240 | /* This is enough as block is already zeroed and entry list is empty... */ | ||
241 | info->dqi_free_entry = blk; | ||
242 | mark_info_dirty(dquot->dq_sb, dquot->dq_type); | ||
243 | } | ||
244 | /* Block will be full? */ | ||
245 | if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) { | ||
246 | *err = remove_free_dqentry(info, buf, blk); | ||
247 | if (*err < 0) { | ||
248 | printk(KERN_ERR "VFS: find_free_dqentry(): Can't " | ||
249 | "remove block (%u) from entry free list.\n", | ||
250 | blk); | ||
251 | goto out_buf; | ||
252 | } | ||
253 | } | ||
254 | le16_add_cpu(&dh->dqdh_entries, 1); | ||
255 | /* Find free structure in block */ | ||
256 | for (i = 0, ddquot = ((char *)buf) + sizeof(struct qt_disk_dqdbheader); | ||
257 | i < qtree_dqstr_in_blk(info) && !qtree_entry_unused(info, ddquot); | ||
258 | i++, ddquot += info->dqi_entry_size); | ||
259 | #ifdef __QUOTA_QT_PARANOIA | ||
260 | if (i == qtree_dqstr_in_blk(info)) { | ||
261 | printk(KERN_ERR "VFS: find_free_dqentry(): Data block full " | ||
262 | "but it shouldn't.\n"); | ||
263 | *err = -EIO; | ||
264 | goto out_buf; | ||
265 | } | ||
266 | #endif | ||
267 | *err = write_blk(info, blk, buf); | ||
268 | if (*err < 0) { | ||
269 | printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota " | ||
270 | "data block %u.\n", blk); | ||
271 | goto out_buf; | ||
272 | } | ||
273 | dquot->dq_off = (blk << info->dqi_blocksize_bits) + | ||
274 | sizeof(struct qt_disk_dqdbheader) + | ||
275 | i * info->dqi_entry_size; | ||
276 | freedqbuf(buf); | ||
277 | return blk; | ||
278 | out_buf: | ||
279 | freedqbuf(buf); | ||
280 | return 0; | ||
281 | } | ||
282 | |||
283 | /* Insert reference to structure into the trie */ | ||
284 | static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, | ||
285 | uint *treeblk, int depth) | ||
286 | { | ||
287 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
288 | int ret = 0, newson = 0, newact = 0; | ||
289 | __le32 *ref; | ||
290 | uint newblk; | ||
291 | |||
292 | if (!buf) | ||
293 | return -ENOMEM; | ||
294 | if (!*treeblk) { | ||
295 | ret = get_free_dqblk(info); | ||
296 | if (ret < 0) | ||
297 | goto out_buf; | ||
298 | *treeblk = ret; | ||
299 | memset(buf, 0, info->dqi_usable_bs); | ||
300 | newact = 1; | ||
301 | } else { | ||
302 | ret = read_blk(info, *treeblk, buf); | ||
303 | if (ret < 0) { | ||
304 | printk(KERN_ERR "VFS: Can't read tree quota block " | ||
305 | "%u.\n", *treeblk); | ||
306 | goto out_buf; | ||
307 | } | ||
308 | } | ||
309 | ref = (__le32 *)buf; | ||
310 | newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); | ||
311 | if (!newblk) | ||
312 | newson = 1; | ||
313 | if (depth == info->dqi_qtree_depth - 1) { | ||
314 | #ifdef __QUOTA_QT_PARANOIA | ||
315 | if (newblk) { | ||
316 | printk(KERN_ERR "VFS: Inserting already present quota " | ||
317 | "entry (block %u).\n", | ||
318 | le32_to_cpu(ref[get_index(info, | ||
319 | dquot->dq_id, depth)])); | ||
320 | ret = -EIO; | ||
321 | goto out_buf; | ||
322 | } | ||
323 | #endif | ||
324 | newblk = find_free_dqentry(info, dquot, &ret); | ||
325 | } else { | ||
326 | ret = do_insert_tree(info, dquot, &newblk, depth+1); | ||
327 | } | ||
328 | if (newson && ret >= 0) { | ||
329 | ref[get_index(info, dquot->dq_id, depth)] = | ||
330 | cpu_to_le32(newblk); | ||
331 | ret = write_blk(info, *treeblk, buf); | ||
332 | } else if (newact && ret < 0) { | ||
333 | put_free_dqblk(info, buf, *treeblk); | ||
334 | } | ||
335 | out_buf: | ||
336 | freedqbuf(buf); | ||
337 | return ret; | ||
338 | } | ||
339 | |||
340 | /* Wrapper for inserting quota structure into tree */ | ||
341 | static inline int dq_insert_tree(struct qtree_mem_dqinfo *info, | ||
342 | struct dquot *dquot) | ||
343 | { | ||
344 | int tmp = QT_TREEOFF; | ||
345 | return do_insert_tree(info, dquot, &tmp, 0); | ||
346 | } | ||
347 | |||
348 | /* | ||
349 | * We don't have to be afraid of deadlocks as we never have quotas on quota files... | ||
350 | */ | ||
351 | int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot) | ||
352 | { | ||
353 | int type = dquot->dq_type; | ||
354 | struct super_block *sb = dquot->dq_sb; | ||
355 | ssize_t ret; | ||
356 | dqbuf_t ddquot = getdqbuf(info->dqi_entry_size); | ||
357 | |||
358 | if (!ddquot) | ||
359 | return -ENOMEM; | ||
360 | |||
361 | /* dq_off is guarded by dqio_mutex */ | ||
362 | if (!dquot->dq_off) { | ||
363 | ret = dq_insert_tree(info, dquot); | ||
364 | if (ret < 0) { | ||
365 | printk(KERN_ERR "VFS: Error %zd occurred while " | ||
366 | "creating quota.\n", ret); | ||
367 | freedqbuf(ddquot); | ||
368 | return ret; | ||
369 | } | ||
370 | } | ||
371 | spin_lock(&dq_data_lock); | ||
372 | info->dqi_ops->mem2disk_dqblk(ddquot, dquot); | ||
373 | spin_unlock(&dq_data_lock); | ||
374 | ret = sb->s_op->quota_write(sb, type, (char *)ddquot, | ||
375 | info->dqi_entry_size, dquot->dq_off); | ||
376 | if (ret != info->dqi_entry_size) { | ||
377 | printk(KERN_WARNING "VFS: dquota write failed on dev %s\n", | ||
378 | sb->s_id); | ||
379 | if (ret >= 0) | ||
380 | ret = -ENOSPC; | ||
381 | } else { | ||
382 | ret = 0; | ||
383 | } | ||
384 | dqstats.writes++; | ||
385 | freedqbuf(ddquot); | ||
386 | |||
387 | return ret; | ||
388 | } | ||
389 | EXPORT_SYMBOL(qtree_write_dquot); | ||
390 | |||
391 | /* Free dquot entry in data block */ | ||
392 | static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot, | ||
393 | uint blk) | ||
394 | { | ||
395 | struct qt_disk_dqdbheader *dh; | ||
396 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
397 | int ret = 0; | ||
398 | |||
399 | if (!buf) | ||
400 | return -ENOMEM; | ||
401 | if (dquot->dq_off >> info->dqi_blocksize_bits != blk) { | ||
402 | printk(KERN_ERR "VFS: Quota structure has offset to other " | ||
403 | "block (%u) than it should (%u).\n", blk, | ||
404 | (uint)(dquot->dq_off >> info->dqi_blocksize_bits)); | ||
405 | goto out_buf; | ||
406 | } | ||
407 | ret = read_blk(info, blk, buf); | ||
408 | if (ret < 0) { | ||
409 | printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk); | ||
410 | goto out_buf; | ||
411 | } | ||
412 | dh = (struct qt_disk_dqdbheader *)buf; | ||
413 | le16_add_cpu(&dh->dqdh_entries, -1); | ||
414 | if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */ | ||
415 | ret = remove_free_dqentry(info, buf, blk); | ||
416 | if (ret >= 0) | ||
417 | ret = put_free_dqblk(info, buf, blk); | ||
418 | if (ret < 0) { | ||
419 | printk(KERN_ERR "VFS: Can't move quota data block (%u) " | ||
420 | "to free list.\n", blk); | ||
421 | goto out_buf; | ||
422 | } | ||
423 | } else { | ||
424 | memset(buf + | ||
425 | (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)), | ||
426 | 0, info->dqi_entry_size); | ||
427 | if (le16_to_cpu(dh->dqdh_entries) == | ||
428 | qtree_dqstr_in_blk(info) - 1) { | ||
429 | /* Insert will write block itself */ | ||
430 | ret = insert_free_dqentry(info, buf, blk); | ||
431 | if (ret < 0) { | ||
432 | printk(KERN_ERR "VFS: Can't insert quota data " | ||
433 | "block (%u) to free entry list.\n", blk); | ||
434 | goto out_buf; | ||
435 | } | ||
436 | } else { | ||
437 | ret = write_blk(info, blk, buf); | ||
438 | if (ret < 0) { | ||
439 | printk(KERN_ERR "VFS: Can't write quota data " | ||
440 | "block %u\n", blk); | ||
441 | goto out_buf; | ||
442 | } | ||
443 | } | ||
444 | } | ||
445 | dquot->dq_off = 0; /* Quota is now unattached */ | ||
446 | out_buf: | ||
447 | freedqbuf(buf); | ||
448 | return ret; | ||
449 | } | ||
450 | |||
451 | /* Remove reference to dquot from tree */ | ||
452 | static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, | ||
453 | uint *blk, int depth) | ||
454 | { | ||
455 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
456 | int ret = 0; | ||
457 | uint newblk; | ||
458 | __le32 *ref = (__le32 *)buf; | ||
459 | |||
460 | if (!buf) | ||
461 | return -ENOMEM; | ||
462 | ret = read_blk(info, *blk, buf); | ||
463 | if (ret < 0) { | ||
464 | printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk); | ||
465 | goto out_buf; | ||
466 | } | ||
467 | newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); | ||
468 | if (depth == info->dqi_qtree_depth - 1) { | ||
469 | ret = free_dqentry(info, dquot, newblk); | ||
470 | newblk = 0; | ||
471 | } else { | ||
472 | ret = remove_tree(info, dquot, &newblk, depth+1); | ||
473 | } | ||
474 | if (ret >= 0 && !newblk) { | ||
475 | int i; | ||
476 | ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0); | ||
477 | /* Block got empty? */ | ||
478 | for (i = 0; | ||
479 | i < (info->dqi_usable_bs >> 2) && !ref[i]; | ||
480 | i++); | ||
481 | /* Don't put the root block into the free block list */ | ||
482 | if (i == (info->dqi_usable_bs >> 2) | ||
483 | && *blk != QT_TREEOFF) { | ||
484 | put_free_dqblk(info, buf, *blk); | ||
485 | *blk = 0; | ||
486 | } else { | ||
487 | ret = write_blk(info, *blk, buf); | ||
488 | if (ret < 0) | ||
489 | printk(KERN_ERR "VFS: Can't write quota tree " | ||
490 | "block %u.\n", *blk); | ||
491 | } | ||
492 | } | ||
493 | out_buf: | ||
494 | freedqbuf(buf); | ||
495 | return ret; | ||
496 | } | ||
497 | |||
498 | /* Delete dquot from tree */ | ||
499 | int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot) | ||
500 | { | ||
501 | uint tmp = QT_TREEOFF; | ||
502 | |||
503 | if (!dquot->dq_off) /* Even not allocated? */ | ||
504 | return 0; | ||
505 | return remove_tree(info, dquot, &tmp, 0); | ||
506 | } | ||
507 | EXPORT_SYMBOL(qtree_delete_dquot); | ||
508 | |||
509 | /* Find entry in block */ | ||
510 | static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info, | ||
511 | struct dquot *dquot, uint blk) | ||
512 | { | ||
513 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
514 | loff_t ret = 0; | ||
515 | int i; | ||
516 | char *ddquot; | ||
517 | |||
518 | if (!buf) | ||
519 | return -ENOMEM; | ||
520 | ret = read_blk(info, blk, buf); | ||
521 | if (ret < 0) { | ||
522 | printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk); | ||
523 | goto out_buf; | ||
524 | } | ||
525 | for (i = 0, ddquot = ((char *)buf) + sizeof(struct qt_disk_dqdbheader); | ||
526 | i < qtree_dqstr_in_blk(info) && !info->dqi_ops->is_id(ddquot, dquot); | ||
527 | i++, ddquot += info->dqi_entry_size); | ||
528 | if (i == qtree_dqstr_in_blk(info)) { | ||
529 | printk(KERN_ERR "VFS: Quota for id %u referenced " | ||
530 | "but not present.\n", dquot->dq_id); | ||
531 | ret = -EIO; | ||
532 | goto out_buf; | ||
533 | } else { | ||
534 | ret = (blk << info->dqi_blocksize_bits) + sizeof(struct | ||
535 | qt_disk_dqdbheader) + i * info->dqi_entry_size; | ||
536 | } | ||
537 | out_buf: | ||
538 | freedqbuf(buf); | ||
539 | return ret; | ||
540 | } | ||
541 | |||
542 | /* Find entry for given id in the tree */ | ||
543 | static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info, | ||
544 | struct dquot *dquot, uint blk, int depth) | ||
545 | { | ||
546 | dqbuf_t buf = getdqbuf(info->dqi_usable_bs); | ||
547 | loff_t ret = 0; | ||
548 | __le32 *ref = (__le32 *)buf; | ||
549 | |||
550 | if (!buf) | ||
551 | return -ENOMEM; | ||
552 | ret = read_blk(info, blk, buf); | ||
553 | if (ret < 0) { | ||
554 | printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk); | ||
555 | goto out_buf; | ||
556 | } | ||
557 | ret = 0; | ||
558 | blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); | ||
559 | if (!blk) /* No reference? */ | ||
560 | goto out_buf; | ||
561 | if (depth < info->dqi_qtree_depth - 1) | ||
562 | ret = find_tree_dqentry(info, dquot, blk, depth+1); | ||
563 | else | ||
564 | ret = find_block_dqentry(info, dquot, blk); | ||
565 | out_buf: | ||
566 | freedqbuf(buf); | ||
567 | return ret; | ||
568 | } | ||
569 | |||
570 | /* Find entry for given id in the tree - wrapper function */ | ||
571 | static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info, | ||
572 | struct dquot *dquot) | ||
573 | { | ||
574 | return find_tree_dqentry(info, dquot, QT_TREEOFF, 0); | ||
575 | } | ||
576 | |||
577 | int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot) | ||
578 | { | ||
579 | int type = dquot->dq_type; | ||
580 | struct super_block *sb = dquot->dq_sb; | ||
581 | loff_t offset; | ||
582 | dqbuf_t ddquot; | ||
583 | int ret = 0; | ||
584 | |||
585 | #ifdef __QUOTA_QT_PARANOIA | ||
586 | /* Invalidated quota? */ | ||
587 | if (!sb_dqopt(dquot->dq_sb)->files[type]) { | ||
588 | printk(KERN_ERR "VFS: Quota invalidated while reading!\n"); | ||
589 | return -EIO; | ||
590 | } | ||
591 | #endif | ||
592 | /* Do we know offset of the dquot entry in the quota file? */ | ||
593 | if (!dquot->dq_off) { | ||
594 | offset = find_dqentry(info, dquot); | ||
595 | if (offset <= 0) { /* Entry not present? */ | ||
596 | if (offset < 0) | ||
597 | printk(KERN_ERR "VFS: Can't read quota " | ||
598 | "structure for id %u.\n", dquot->dq_id); | ||
599 | dquot->dq_off = 0; | ||
600 | set_bit(DQ_FAKE_B, &dquot->dq_flags); | ||
601 | memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk)); | ||
602 | ret = offset; | ||
603 | goto out; | ||
604 | } | ||
605 | dquot->dq_off = offset; | ||
606 | } | ||
607 | ddquot = getdqbuf(info->dqi_entry_size); | ||
608 | if (!ddquot) | ||
609 | return -ENOMEM; | ||
610 | ret = sb->s_op->quota_read(sb, type, (char *)ddquot, | ||
611 | info->dqi_entry_size, dquot->dq_off); | ||
612 | if (ret != info->dqi_entry_size) { | ||
613 | if (ret >= 0) | ||
614 | ret = -EIO; | ||
615 | printk(KERN_ERR "VFS: Error while reading quota " | ||
616 | "structure for id %u.\n", dquot->dq_id); | ||
617 | set_bit(DQ_FAKE_B, &dquot->dq_flags); | ||
618 | memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk)); | ||
619 | freedqbuf(ddquot); | ||
620 | goto out; | ||
621 | } | ||
622 | spin_lock(&dq_data_lock); | ||
623 | info->dqi_ops->disk2mem_dqblk(dquot, ddquot); | ||
624 | if (!dquot->dq_dqb.dqb_bhardlimit && | ||
625 | !dquot->dq_dqb.dqb_bsoftlimit && | ||
626 | !dquot->dq_dqb.dqb_ihardlimit && | ||
627 | !dquot->dq_dqb.dqb_isoftlimit) | ||
628 | set_bit(DQ_FAKE_B, &dquot->dq_flags); | ||
629 | spin_unlock(&dq_data_lock); | ||
630 | freedqbuf(ddquot); | ||
631 | out: | ||
632 | dqstats.reads++; | ||
633 | return ret; | ||
634 | } | ||
635 | EXPORT_SYMBOL(qtree_read_dquot); | ||
636 | |||
637 | /* Check whether dquot should not be deleted. We know we are | ||
638 | * the only one operating on dquot (thanks to dq_lock) */ | ||
639 | int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot) | ||
640 | { | ||
641 | if (test_bit(DQ_FAKE_B, &dquot->dq_flags) && !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace)) | ||
642 | return qtree_delete_dquot(info, dquot); | ||
643 | return 0; | ||
644 | } | ||
645 | EXPORT_SYMBOL(qtree_release_dquot); | ||