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 static inline int do_check_range(struct super_block *sb, const char *val_name,
83 uint val, uint min_val, uint max_val)
85 if (val < min_val || val > max_val) {
86 quota_error(sb, "Getting %s %u out of range %u-%u",
87 val_name, val, min_val, max_val);
94 static int check_dquot_block_header(struct qtree_mem_dqinfo *info,
95 struct qt_disk_dqdbheader *dh)
99 err = do_check_range(info->dqi_sb, "dqdh_next_free",
100 le32_to_cpu(dh->dqdh_next_free), 0,
101 info->dqi_blocks - 1);
104 err = do_check_range(info->dqi_sb, "dqdh_prev_free",
105 le32_to_cpu(dh->dqdh_prev_free), 0,
106 info->dqi_blocks - 1);
111 /* Remove empty block from list and return it */
112 static int get_free_dqblk(struct qtree_mem_dqinfo *info)
114 char *buf = getdqbuf(info->dqi_usable_bs);
115 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
120 if (info->dqi_free_blk) {
121 blk = info->dqi_free_blk;
122 ret = read_blk(info, blk, buf);
125 ret = check_dquot_block_header(info, dh);
128 info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
131 memset(buf, 0, info->dqi_usable_bs);
132 /* Assure block allocation... */
133 ret = write_blk(info, info->dqi_blocks, buf);
136 blk = info->dqi_blocks++;
138 mark_info_dirty(info->dqi_sb, info->dqi_type);
145 /* Insert empty block to the list */
146 static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
148 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
151 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
152 dh->dqdh_prev_free = cpu_to_le32(0);
153 dh->dqdh_entries = cpu_to_le16(0);
154 err = write_blk(info, blk, buf);
157 info->dqi_free_blk = blk;
158 mark_info_dirty(info->dqi_sb, info->dqi_type);
162 /* Remove given block from the list of blocks with free entries */
163 static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
166 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
167 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
168 uint nextblk = le32_to_cpu(dh->dqdh_next_free);
169 uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
175 err = read_blk(info, nextblk, tmpbuf);
178 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
180 err = write_blk(info, nextblk, tmpbuf);
185 err = read_blk(info, prevblk, tmpbuf);
188 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
190 err = write_blk(info, prevblk, tmpbuf);
194 info->dqi_free_entry = nextblk;
195 mark_info_dirty(info->dqi_sb, info->dqi_type);
198 dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
199 /* No matter whether write succeeds block is out of list */
200 if (write_blk(info, blk, buf) < 0)
201 quota_error(info->dqi_sb, "Can't write block (%u) "
202 "with free entries", blk);
209 /* Insert given block to the beginning of list with free entries */
210 static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
213 char *tmpbuf = getdqbuf(info->dqi_usable_bs);
214 struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
219 dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
220 dh->dqdh_prev_free = cpu_to_le32(0);
221 err = write_blk(info, blk, buf);
224 if (info->dqi_free_entry) {
225 err = read_blk(info, info->dqi_free_entry, tmpbuf);
228 ((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
230 err = write_blk(info, info->dqi_free_entry, tmpbuf);
235 info->dqi_free_entry = blk;
236 mark_info_dirty(info->dqi_sb, info->dqi_type);
243 /* Is the entry in the block free? */
244 int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
248 for (i = 0; i < info->dqi_entry_size; i++)
253 EXPORT_SYMBOL(qtree_entry_unused);
255 /* Find space for dquot */
256 static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
257 struct dquot *dquot, int *err)
260 struct qt_disk_dqdbheader *dh;
261 char *buf = getdqbuf(info->dqi_usable_bs);
269 dh = (struct qt_disk_dqdbheader *)buf;
270 if (info->dqi_free_entry) {
271 blk = info->dqi_free_entry;
272 *err = read_blk(info, blk, buf);
275 *err = check_dquot_block_header(info, dh);
279 blk = get_free_dqblk(info);
285 memset(buf, 0, info->dqi_usable_bs);
286 /* This is enough as the block is already zeroed and the entry
287 * list is empty... */
288 info->dqi_free_entry = blk;
289 mark_info_dirty(dquot->dq_sb, dquot->dq_id.type);
291 /* Block will be full? */
292 if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
293 *err = remove_free_dqentry(info, buf, blk);
295 quota_error(dquot->dq_sb, "Can't remove block (%u) "
296 "from entry free list", blk);
300 le16_add_cpu(&dh->dqdh_entries, 1);
301 /* Find free structure in block */
302 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
303 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
304 if (qtree_entry_unused(info, ddquot))
306 ddquot += info->dqi_entry_size;
308 #ifdef __QUOTA_QT_PARANOIA
309 if (i == qtree_dqstr_in_blk(info)) {
310 quota_error(dquot->dq_sb, "Data block full but it shouldn't");
315 *err = write_blk(info, blk, buf);
317 quota_error(dquot->dq_sb, "Can't write quota data block %u",
321 dquot->dq_off = ((loff_t)blk << info->dqi_blocksize_bits) +
322 sizeof(struct qt_disk_dqdbheader) +
323 i * info->dqi_entry_size;
331 /* Insert reference to structure into the trie */
332 static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
333 uint *treeblk, int depth)
335 char *buf = getdqbuf(info->dqi_usable_bs);
336 int ret = 0, newson = 0, newact = 0;
343 ret = get_free_dqblk(info);
347 memset(buf, 0, info->dqi_usable_bs);
350 ret = read_blk(info, *treeblk, buf);
352 quota_error(dquot->dq_sb, "Can't read tree quota "
353 "block %u", *treeblk);
358 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
361 if (depth == info->dqi_qtree_depth - 1) {
362 #ifdef __QUOTA_QT_PARANOIA
364 quota_error(dquot->dq_sb, "Inserting already present "
365 "quota entry (block %u)",
366 le32_to_cpu(ref[get_index(info,
367 dquot->dq_id, depth)]));
372 newblk = find_free_dqentry(info, dquot, &ret);
374 ret = do_insert_tree(info, dquot, &newblk, depth+1);
376 if (newson && ret >= 0) {
377 ref[get_index(info, dquot->dq_id, depth)] =
379 ret = write_blk(info, *treeblk, buf);
380 } else if (newact && ret < 0) {
381 put_free_dqblk(info, buf, *treeblk);
388 /* Wrapper for inserting quota structure into tree */
389 static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
392 int tmp = QT_TREEOFF;
394 #ifdef __QUOTA_QT_PARANOIA
395 if (info->dqi_blocks <= QT_TREEOFF) {
396 quota_error(dquot->dq_sb, "Quota tree root isn't allocated!");
400 return do_insert_tree(info, dquot, &tmp, 0);
404 * We don't have to be afraid of deadlocks as we never have quotas on quota
407 int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
409 int type = dquot->dq_id.type;
410 struct super_block *sb = dquot->dq_sb;
412 char *ddquot = getdqbuf(info->dqi_entry_size);
417 /* dq_off is guarded by dqio_sem */
418 if (!dquot->dq_off) {
419 ret = dq_insert_tree(info, dquot);
421 quota_error(sb, "Error %zd occurred while creating "
427 spin_lock(&dquot->dq_dqb_lock);
428 info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
429 spin_unlock(&dquot->dq_dqb_lock);
430 ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
432 if (ret != info->dqi_entry_size) {
433 quota_error(sb, "dquota write failed");
439 dqstats_inc(DQST_WRITES);
444 EXPORT_SYMBOL(qtree_write_dquot);
446 /* Free dquot entry in data block */
447 static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
450 struct qt_disk_dqdbheader *dh;
451 char *buf = getdqbuf(info->dqi_usable_bs);
456 if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
457 quota_error(dquot->dq_sb, "Quota structure has offset to "
458 "other block (%u) than it should (%u)", blk,
459 (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
463 ret = read_blk(info, blk, buf);
465 quota_error(dquot->dq_sb, "Can't read quota data block %u",
469 dh = (struct qt_disk_dqdbheader *)buf;
470 ret = check_dquot_block_header(info, dh);
473 le16_add_cpu(&dh->dqdh_entries, -1);
474 if (!le16_to_cpu(dh->dqdh_entries)) { /* Block got free? */
475 ret = remove_free_dqentry(info, buf, blk);
477 ret = put_free_dqblk(info, buf, blk);
479 quota_error(dquot->dq_sb, "Can't move quota data block "
480 "(%u) to free list", blk);
485 (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
486 0, info->dqi_entry_size);
487 if (le16_to_cpu(dh->dqdh_entries) ==
488 qtree_dqstr_in_blk(info) - 1) {
489 /* Insert will write block itself */
490 ret = insert_free_dqentry(info, buf, blk);
492 quota_error(dquot->dq_sb, "Can't insert quota "
493 "data block (%u) to free entry list", blk);
497 ret = write_blk(info, blk, buf);
499 quota_error(dquot->dq_sb, "Can't write quota "
500 "data block %u", blk);
505 dquot->dq_off = 0; /* Quota is now unattached */
511 /* Remove reference to dquot from tree */
512 static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
513 uint *blk, int depth)
515 char *buf = getdqbuf(info->dqi_usable_bs);
518 __le32 *ref = (__le32 *)buf;
522 ret = read_blk(info, *blk, buf);
524 quota_error(dquot->dq_sb, "Can't read quota data block %u",
528 newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
529 if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) {
530 quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
531 newblk, info->dqi_blocks);
536 if (depth == info->dqi_qtree_depth - 1) {
537 ret = free_dqentry(info, dquot, newblk);
540 ret = remove_tree(info, dquot, &newblk, depth+1);
542 if (ret >= 0 && !newblk) {
544 ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
545 /* Block got empty? */
546 for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
548 /* Don't put the root block into the free block list */
549 if (i == (info->dqi_usable_bs >> 2)
550 && *blk != QT_TREEOFF) {
551 put_free_dqblk(info, buf, *blk);
554 ret = write_blk(info, *blk, buf);
556 quota_error(dquot->dq_sb,
557 "Can't write quota tree block %u",
566 /* Delete dquot from tree */
567 int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
569 uint tmp = QT_TREEOFF;
571 if (!dquot->dq_off) /* Even not allocated? */
573 return remove_tree(info, dquot, &tmp, 0);
575 EXPORT_SYMBOL(qtree_delete_dquot);
577 /* Find entry in block */
578 static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
579 struct dquot *dquot, uint blk)
581 char *buf = getdqbuf(info->dqi_usable_bs);
588 ret = read_blk(info, blk, buf);
590 quota_error(dquot->dq_sb, "Can't read quota tree "
594 ddquot = buf + sizeof(struct qt_disk_dqdbheader);
595 for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
596 if (info->dqi_ops->is_id(ddquot, dquot))
598 ddquot += info->dqi_entry_size;
600 if (i == qtree_dqstr_in_blk(info)) {
601 quota_error(dquot->dq_sb,
602 "Quota for id %u referenced but not present",
603 from_kqid(&init_user_ns, dquot->dq_id));
607 ret = ((loff_t)blk << info->dqi_blocksize_bits) + sizeof(struct
608 qt_disk_dqdbheader) + i * info->dqi_entry_size;
615 /* Find entry for given id in the tree */
616 static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
617 struct dquot *dquot, uint blk, int depth)
619 char *buf = getdqbuf(info->dqi_usable_bs);
621 __le32 *ref = (__le32 *)buf;
625 ret = read_blk(info, blk, buf);
627 quota_error(dquot->dq_sb, "Can't read quota tree block %u",
632 blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
633 if (!blk) /* No reference? */
635 if (blk < QT_TREEOFF || blk >= info->dqi_blocks) {
636 quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)",
637 blk, info->dqi_blocks);
642 if (depth < info->dqi_qtree_depth - 1)
643 ret = find_tree_dqentry(info, dquot, blk, depth+1);
645 ret = find_block_dqentry(info, dquot, blk);
651 /* Find entry for given id in the tree - wrapper function */
652 static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
655 return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
658 int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
660 int type = dquot->dq_id.type;
661 struct super_block *sb = dquot->dq_sb;
666 #ifdef __QUOTA_QT_PARANOIA
667 /* Invalidated quota? */
668 if (!sb_dqopt(dquot->dq_sb)->files[type]) {
669 quota_error(sb, "Quota invalidated while reading!");
673 /* Do we know offset of the dquot entry in the quota file? */
674 if (!dquot->dq_off) {
675 offset = find_dqentry(info, dquot);
676 if (offset <= 0) { /* Entry not present? */
678 quota_error(sb,"Can't read quota structure "
680 from_kqid(&init_user_ns,
683 set_bit(DQ_FAKE_B, &dquot->dq_flags);
684 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
688 dquot->dq_off = offset;
690 ddquot = getdqbuf(info->dqi_entry_size);
693 ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
695 if (ret != info->dqi_entry_size) {
698 quota_error(sb, "Error while reading quota structure for id %u",
699 from_kqid(&init_user_ns, dquot->dq_id));
700 set_bit(DQ_FAKE_B, &dquot->dq_flags);
701 memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
705 spin_lock(&dquot->dq_dqb_lock);
706 info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
707 if (!dquot->dq_dqb.dqb_bhardlimit &&
708 !dquot->dq_dqb.dqb_bsoftlimit &&
709 !dquot->dq_dqb.dqb_ihardlimit &&
710 !dquot->dq_dqb.dqb_isoftlimit)
711 set_bit(DQ_FAKE_B, &dquot->dq_flags);
712 spin_unlock(&dquot->dq_dqb_lock);
715 dqstats_inc(DQST_READS);
718 EXPORT_SYMBOL(qtree_read_dquot);
720 /* Check whether dquot should not be deleted. We know we are
721 * the only one operating on dquot (thanks to dq_lock) */
722 int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
724 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
725 !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
726 return qtree_delete_dquot(info, dquot);
729 EXPORT_SYMBOL(qtree_release_dquot);
731 static int find_next_id(struct qtree_mem_dqinfo *info, qid_t *id,
732 unsigned int blk, int depth)
734 char *buf = getdqbuf(info->dqi_usable_bs);
735 __le32 *ref = (__le32 *)buf;
737 unsigned int epb = info->dqi_usable_bs >> 2;
738 unsigned int level_inc = 1;
744 for (i = depth; i < info->dqi_qtree_depth - 1; i++)
747 ret = read_blk(info, blk, buf);
749 quota_error(info->dqi_sb,
750 "Can't read quota tree block %u", blk);
753 for (i = __get_index(info, *id, depth); i < epb; i++) {
754 if (ref[i] == cpu_to_le32(0)) {
758 if (depth == info->dqi_qtree_depth - 1) {
762 ret = find_next_id(info, id, le32_to_cpu(ref[i]), depth + 1);
775 int qtree_get_next_id(struct qtree_mem_dqinfo *info, struct kqid *qid)
777 qid_t id = from_kqid(&init_user_ns, *qid);
780 ret = find_next_id(info, &id, QT_TREEOFF, 0);
783 *qid = make_kqid(&init_user_ns, qid->type, id);
786 EXPORT_SYMBOL(qtree_get_next_id);