2 * vfsv0 quota IO operations on file
5 #include <linux/errno.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>
15 #include <asm/byteorder.h>
17 #include "quota_tree.h"
19 MODULE_AUTHOR("Jan Kara");
20 MODULE_DESCRIPTION("Quota trie support");
21 MODULE_LICENSE("GPL");
23 #define __QUOTA_QT_PARANOIA
25 static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
27 unsigned int epb = info->dqi_usable_bs >> 2;
29 depth = info->dqi_qtree_depth - depth - 1;
35 static int get_index(struct qtree_mem_dqinfo *info, struct kqid qid, int depth)
37 qid_t id = from_kqid(&init_user_ns, qid);
39 return __get_index(info, id, depth);
42 /* Number of entries in one blocks */
43 static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
45 return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
46 / info->dqi_entry_size;
49 static char *getdqbuf(size_t size)
51 char *buf = kmalloc(size, GFP_NOFS);
54 "VFS: Not enough memory for quota buffers.\n");
58 static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
60 struct super_block *sb = info->dqi_sb;
62 memset(buf, 0, info->dqi_usable_bs);
63 return sb->s_op->quota_read(sb, info->dqi_type, buf,
64 info->dqi_usable_bs, (loff_t)blk << info->dqi_blocksize_bits);
67 static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
69 struct super_block *sb = info->dqi_sb;
72 ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
73 info->dqi_usable_bs, (loff_t)blk << info->dqi_blocksize_bits);
74 if (ret != info->dqi_usable_bs) {
75 quota_error(sb, "dquota write failed");
82 /* Remove empty block from list and return it */
83 static int get_free_dqblk(struct qtree_mem_dqinfo *info)
85 char *buf = getdqbuf(info->dqi_usable_bs);
86 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
91 if (info->dqi_free_blk) {
92 blk = info->dqi_free_blk;
93 ret = read_blk(info, blk, buf);
96 info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
99 memset(buf, 0, info->dqi_usable_bs);
100 /* Assure block allocation... */
101 ret = write_blk(info, info->dqi_blocks, buf);
104 blk = info->dqi_blocks++;
106 mark_info_dirty(info->dqi_sb, info->dqi_type);
113 /* Insert empty block to the list */
114 static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
116 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
119 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
120 dh->dqdh_prev_free = cpu_to_le32(0);
121 dh->dqdh_entries = cpu_to_le16(0);
122 err = write_blk(info, blk, buf);
125 info->dqi_free_blk = blk;
126 mark_info_dirty(info->dqi_sb, info->dqi_type);
130 /* Remove given block from the list of blocks with free entries */
131 static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
134 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
135 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
136 uint nextblk = le32_to_cpu(dh->dqdh_next_free);
137 uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
143 err = read_blk(info, nextblk, tmpbuf);
146 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
148 err = write_blk(info, nextblk, tmpbuf);
153 err = read_blk(info, prevblk, tmpbuf);
156 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
158 err = write_blk(info, prevblk, tmpbuf);
162 info->dqi_free_entry = nextblk;
163 mark_info_dirty(info->dqi_sb, info->dqi_type);
166 dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
167 /* No matter whether write succeeds block is out of list */
168 if (write_blk(info, blk, buf) < 0)
169 quota_error(info->dqi_sb, "Can't write block (%u) "
170 "with free entries", blk);
177 /* Insert given block to the beginning of list with free entries */
178 static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
181 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
182 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
187 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
188 dh->dqdh_prev_free = cpu_to_le32(0);
189 err = write_blk(info, blk, buf);
192 if (info->dqi_free_entry) {
193 err = read_blk(info, info->dqi_free_entry, tmpbuf);
196 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
198 err = write_blk(info, info->dqi_free_entry, tmpbuf);
203 info->dqi_free_entry = blk;
204 mark_info_dirty(info->dqi_sb, info->dqi_type);
211 /* Is the entry in the block free? */
212 int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
216 for (i = 0; i < info->dqi_entry_size; i++)
221 EXPORT_SYMBOL(qtree_entry_unused);
223 /* Find space for dquot */
224 static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
225 struct dquot *dquot, int *err)
228 struct qt_disk_dqdbheader *dh;
229 char *buf = getdqbuf(info->dqi_usable_bs);
237 dh = (struct qt_disk_dqdbheader *)buf;
238 if (info->dqi_free_entry) {
239 blk = info->dqi_free_entry;
240 *err = read_blk(info, blk, buf);
244 blk = get_free_dqblk(info);
250 memset(buf, 0, info->dqi_usable_bs);
251 /* This is enough as the block is already zeroed and the entry
252 * list is empty... */
253 info->dqi_free_entry = blk;
254 mark_info_dirty(dquot->dq_sb, dquot->dq_id.type);
256 /* Block will be full? */
257 if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
258 *err = remove_free_dqentry(info, buf, blk);
260 quota_error(dquot->dq_sb, "Can't remove block (%u) "
261 "from entry free list", blk);
265 le16_add_cpu(&dh->dqdh_entries, 1);
266 /* Find free structure in block */
267 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
268 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
269 if (qtree_entry_unused(info, ddquot))
271 ddquot += info->dqi_entry_size;
273 #ifdef __QUOTA_QT_PARANOIA
274 if (i == qtree_dqstr_in_blk(info)) {
275 quota_error(dquot->dq_sb, "Data block full but it shouldn't");
280 *err = write_blk(info, blk, buf);
282 quota_error(dquot->dq_sb, "Can't write quota data block %u",
286 dquot->dq_off = ((loff_t)blk << info->dqi_blocksize_bits) +
287 sizeof(struct qt_disk_dqdbheader) +
288 i * info->dqi_entry_size;
296 /* Insert reference to structure into the trie */
297 static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
298 uint *treeblk, int depth)
300 char *buf = getdqbuf(info->dqi_usable_bs);
301 int ret = 0, newson = 0, newact = 0;
308 ret = get_free_dqblk(info);
312 memset(buf, 0, info->dqi_usable_bs);
315 ret = read_blk(info, *treeblk, buf);
317 quota_error(dquot->dq_sb, "Can't read tree quota "
318 "block %u", *treeblk);
323 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
326 if (depth == info->dqi_qtree_depth - 1) {
327 #ifdef __QUOTA_QT_PARANOIA
329 quota_error(dquot->dq_sb, "Inserting already present "
330 "quota entry (block %u)",
331 le32_to_cpu(ref[get_index(info,
332 dquot->dq_id, depth)]));
337 newblk = find_free_dqentry(info, dquot, &ret);
339 ret = do_insert_tree(info, dquot, &newblk, depth+1);
341 if (newson && ret >= 0) {
342 ref[get_index(info, dquot->dq_id, depth)] =
344 ret = write_blk(info, *treeblk, buf);
345 } else if (newact && ret < 0) {
346 put_free_dqblk(info, buf, *treeblk);
353 /* Wrapper for inserting quota structure into tree */
354 static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
357 int tmp = QT_TREEOFF;
359 #ifdef __QUOTA_QT_PARANOIA
360 if (info->dqi_blocks <= QT_TREEOFF) {
361 quota_error(dquot->dq_sb, "Quota tree root isn't allocated!");
365 return do_insert_tree(info, dquot, &tmp, 0);
369 * We don't have to be afraid of deadlocks as we never have quotas on quota
372 int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
374 int type = dquot->dq_id.type;
375 struct super_block *sb = dquot->dq_sb;
377 char *ddquot = getdqbuf(info->dqi_entry_size);
382 /* dq_off is guarded by dqio_mutex */
383 if (!dquot->dq_off) {
384 ret = dq_insert_tree(info, dquot);
386 quota_error(sb, "Error %zd occurred while creating "
392 spin_lock(&dq_data_lock);
393 info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
394 spin_unlock(&dq_data_lock);
395 ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
397 if (ret != info->dqi_entry_size) {
398 quota_error(sb, "dquota write failed");
404 dqstats_inc(DQST_WRITES);
409 EXPORT_SYMBOL(qtree_write_dquot);
411 /* Free dquot entry in data block */
412 static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
415 struct qt_disk_dqdbheader *dh;
416 char *buf = getdqbuf(info->dqi_usable_bs);
421 if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
422 quota_error(dquot->dq_sb, "Quota structure has offset to "
423 "other block (%u) than it should (%u)", blk,
424 (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
428 ret = read_blk(info, blk, buf);
430 quota_error(dquot->dq_sb, "Can't read quota data block %u",
434 dh = (struct qt_disk_dqdbheader *)buf;
435 le16_add_cpu(&dh->dqdh_entries, -1);
436 if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */
437 ret = remove_free_dqentry(info, buf, blk);
439 ret = put_free_dqblk(info, buf, blk);
441 quota_error(dquot->dq_sb, "Can't move quota data block "
442 "(%u) to free list", blk);
447 (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
448 0, info->dqi_entry_size);
449 if (le16_to_cpu(dh->dqdh_entries) ==
450 qtree_dqstr_in_blk(info) - 1) {
451 /* Insert will write block itself */
452 ret = insert_free_dqentry(info, buf, blk);
454 quota_error(dquot->dq_sb, "Can't insert quota "
455 "data block (%u) to free entry list", blk);
459 ret = write_blk(info, blk, buf);
461 quota_error(dquot->dq_sb, "Can't write quota "
462 "data block %u", blk);
467 dquot->dq_off = 0; /* Quota is now unattached */
473 /* Remove reference to dquot from tree */
474 static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
475 uint *blk, int depth)
477 char *buf = getdqbuf(info->dqi_usable_bs);
480 __le32 *ref = (__le32 *)buf;
484 ret = read_blk(info, *blk, buf);
486 quota_error(dquot->dq_sb, "Can't read quota data block %u",
490 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
491 if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) {
492 quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
493 newblk, info->dqi_blocks);
498 if (depth == info->dqi_qtree_depth - 1) {
499 ret = free_dqentry(info, dquot, newblk);
502 ret = remove_tree(info, dquot, &newblk, depth+1);
504 if (ret >= 0 && !newblk) {
506 ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
507 /* Block got empty? */
508 for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
510 /* Don't put the root block into the free block list */
511 if (i == (info->dqi_usable_bs >> 2)
512 && *blk != QT_TREEOFF) {
513 put_free_dqblk(info, buf, *blk);
516 ret = write_blk(info, *blk, buf);
518 quota_error(dquot->dq_sb,
519 "Can't write quota tree block %u",
528 /* Delete dquot from tree */
529 int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
531 uint tmp = QT_TREEOFF;
533 if (!dquot->dq_off) /* Even not allocated? */
535 return remove_tree(info, dquot, &tmp, 0);
537 EXPORT_SYMBOL(qtree_delete_dquot);
539 /* Find entry in block */
540 static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
541 struct dquot *dquot, uint blk)
543 char *buf = getdqbuf(info->dqi_usable_bs);
550 ret = read_blk(info, blk, buf);
552 quota_error(dquot->dq_sb, "Can't read quota tree "
556 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
557 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
558 if (info->dqi_ops->is_id(ddquot, dquot))
560 ddquot += info->dqi_entry_size;
562 if (i == qtree_dqstr_in_blk(info)) {
563 quota_error(dquot->dq_sb,
564 "Quota for id %u referenced but not present",
565 from_kqid(&init_user_ns, dquot->dq_id));
569 ret = ((loff_t)blk << info->dqi_blocksize_bits) + sizeof(struct
570 qt_disk_dqdbheader) + i * info->dqi_entry_size;
577 /* Find entry for given id in the tree */
578 static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
579 struct dquot *dquot, uint blk, int depth)
581 char *buf = getdqbuf(info->dqi_usable_bs);
583 __le32 *ref = (__le32 *)buf;
587 ret = read_blk(info, blk, buf);
589 quota_error(dquot->dq_sb, "Can't read quota tree block %u",
594 blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
595 if (!blk) /* No reference? */
597 if (blk < QT_TREEOFF || blk >= info->dqi_blocks) {
598 quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
599 blk, info->dqi_blocks);
604 if (depth < info->dqi_qtree_depth - 1)
605 ret = find_tree_dqentry(info, dquot, blk, depth+1);
607 ret = find_block_dqentry(info, dquot, blk);
613 /* Find entry for given id in the tree - wrapper function */
614 static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
617 return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
620 int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
622 int type = dquot->dq_id.type;
623 struct super_block *sb = dquot->dq_sb;
628 #ifdef __QUOTA_QT_PARANOIA
629 /* Invalidated quota? */
630 if (!sb_dqopt(dquot->dq_sb)->files[type]) {
631 quota_error(sb, "Quota invalidated while reading!");
635 /* Do we know offset of the dquot entry in the quota file? */
636 if (!dquot->dq_off) {
637 offset = find_dqentry(info, dquot);
638 if (offset <= 0) { /* Entry not present? */
640 quota_error(sb,"Can't read quota structure "
642 from_kqid(&init_user_ns,
645 set_bit(DQ_FAKE_B, &dquot->dq_flags);
646 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
650 dquot->dq_off = offset;
652 ddquot = getdqbuf(info->dqi_entry_size);
655 ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
657 if (ret != info->dqi_entry_size) {
660 quota_error(sb, "Error while reading quota structure for id %u",
661 from_kqid(&init_user_ns, dquot->dq_id));
662 set_bit(DQ_FAKE_B, &dquot->dq_flags);
663 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
667 spin_lock(&dq_data_lock);
668 info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
669 if (!dquot->dq_dqb.dqb_bhardlimit &&
670 !dquot->dq_dqb.dqb_bsoftlimit &&
671 !dquot->dq_dqb.dqb_ihardlimit &&
672 !dquot->dq_dqb.dqb_isoftlimit)
673 set_bit(DQ_FAKE_B, &dquot->dq_flags);
674 spin_unlock(&dq_data_lock);
677 dqstats_inc(DQST_READS);
680 EXPORT_SYMBOL(qtree_read_dquot);
682 /* Check whether dquot should not be deleted. We know we are
683 * the only one operating on dquot (thanks to dq_lock) */
684 int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
686 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
687 !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
688 return qtree_delete_dquot(info, dquot);
691 EXPORT_SYMBOL(qtree_release_dquot);
693 static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
694 unsigned int blk, int depth)
696 char *buf = getdqbuf(info->dqi_usable_bs);
697 __le32 *ref = (__le32 *)buf;
699 unsigned int epb = info->dqi_usable_bs >> 2;
700 unsigned int level_inc = 1;
706 for (i = depth; i < info->dqi_qtree_depth - 1; i++)
709 ret = read_blk(info, blk, buf);
711 quota_error(info->dqi_sb,
712 "Can't read quota tree block %u", blk);
715 for (i = __get_index(info, *id, depth); i < epb; i++) {
716 if (ref[i] == cpu_to_le32(0)) {
720 if (depth == info->dqi_qtree_depth - 1) {
724 ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
737 int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid)
739 qid_t id = from_kqid(&init_user_ns, *qid);
742 ret = find_next_id(info, &id, QT_TREEOFF, 0);
745 *qid = make_kqid(&init_user_ns, qid->type, id);
748 EXPORT_SYMBOL(qtree_get_next_id);