2 * linux/fs/ext3/ialloc.c
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
9 * BSD ufs-inspired inode and directory allocation by
10 * Stephen Tweedie (sct@redhat.com), 1993
11 * Big-endian to little-endian byte-swapping/bitmaps by
12 * David S. Miller (davem@caip.rutgers.edu), 1995
15 #include <linux/time.h>
17 #include <linux/jbd.h>
18 #include <linux/ext3_fs.h>
19 #include <linux/ext3_jbd.h>
20 #include <linux/stat.h>
21 #include <linux/string.h>
22 #include <linux/quotaops.h>
23 #include <linux/buffer_head.h>
24 #include <linux/random.h>
25 #include <linux/bitops.h>
27 #include <asm/byteorder.h>
34 * ialloc.c contains the inodes allocation and deallocation routines
38 * The free inodes are managed by bitmaps. A file system contains several
39 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
40 * block for inodes, N blocks for the inode table and data blocks.
42 * The file system contains group descriptors which are located after the
43 * super block. Each descriptor contains the number of the bitmap block and
44 * the free blocks count in the block.
49 * Read the inode allocation bitmap for a given block_group, reading
50 * into the specified slot in the superblock's bitmap cache.
52 * Return buffer_head of bitmap on success or NULL.
54 static struct buffer_head
*
55 read_inode_bitmap(struct super_block
* sb
, unsigned long block_group
)
57 struct ext3_group_desc
*desc
;
58 struct buffer_head
*bh
= NULL
;
60 desc
= ext3_get_group_desc(sb
, block_group
, NULL
);
64 bh
= sb_bread(sb
, le32_to_cpu(desc
->bg_inode_bitmap
));
66 ext3_error(sb
, "read_inode_bitmap",
67 "Cannot read inode bitmap - "
68 "block_group = %lu, inode_bitmap = %u",
69 block_group
, le32_to_cpu(desc
->bg_inode_bitmap
));
75 * NOTE! When we get the inode, we're the only people
76 * that have access to it, and as such there are no
77 * race conditions we have to worry about. The inode
78 * is not on the hash-lists, and it cannot be reached
79 * through the filesystem because the directory entry
80 * has been deleted earlier.
82 * HOWEVER: we must make sure that we get no aliases,
83 * which means that we have to call "clear_inode()"
84 * _before_ we mark the inode not in use in the inode
85 * bitmaps. Otherwise a newly created file might use
86 * the same inode number (not actually the same pointer
87 * though), and then we'd have two inodes sharing the
88 * same inode number and space on the harddisk.
90 void ext3_free_inode (handle_t
*handle
, struct inode
* inode
)
92 struct super_block
* sb
= inode
->i_sb
;
95 struct buffer_head
*bitmap_bh
= NULL
;
96 struct buffer_head
*bh2
;
97 unsigned long block_group
;
99 struct ext3_group_desc
* gdp
;
100 struct ext3_super_block
* es
;
101 struct ext3_sb_info
*sbi
;
104 if (atomic_read(&inode
->i_count
) > 1) {
105 printk ("ext3_free_inode: inode has count=%d\n",
106 atomic_read(&inode
->i_count
));
109 if (inode
->i_nlink
) {
110 printk ("ext3_free_inode: inode has nlink=%d\n",
115 printk("ext3_free_inode: inode on nonexistent device\n");
121 ext3_debug ("freeing inode %lu\n", ino
);
124 * Note: we must free any quota before locking the superblock,
125 * as writing the quota to disk may need the lock as well.
128 ext3_xattr_delete_inode(handle
, inode
);
129 DQUOT_FREE_INODE(inode
);
132 is_directory
= S_ISDIR(inode
->i_mode
);
134 /* Do this BEFORE marking the inode not in use or returning an error */
137 es
= EXT3_SB(sb
)->s_es
;
138 if (ino
< EXT3_FIRST_INO(sb
) || ino
> le32_to_cpu(es
->s_inodes_count
)) {
139 ext3_error (sb
, "ext3_free_inode",
140 "reserved or nonexistent inode %lu", ino
);
143 block_group
= (ino
- 1) / EXT3_INODES_PER_GROUP(sb
);
144 bit
= (ino
- 1) % EXT3_INODES_PER_GROUP(sb
);
145 bitmap_bh
= read_inode_bitmap(sb
, block_group
);
149 BUFFER_TRACE(bitmap_bh
, "get_write_access");
150 fatal
= ext3_journal_get_write_access(handle
, bitmap_bh
);
154 /* Ok, now we can actually update the inode bitmaps.. */
155 if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi
, block_group
),
156 bit
, bitmap_bh
->b_data
))
157 ext3_error (sb
, "ext3_free_inode",
158 "bit already cleared for inode %lu", ino
);
160 gdp
= ext3_get_group_desc (sb
, block_group
, &bh2
);
162 BUFFER_TRACE(bh2
, "get_write_access");
163 fatal
= ext3_journal_get_write_access(handle
, bh2
);
164 if (fatal
) goto error_return
;
167 spin_lock(sb_bgl_lock(sbi
, block_group
));
168 gdp
->bg_free_inodes_count
= cpu_to_le16(
169 le16_to_cpu(gdp
->bg_free_inodes_count
) + 1);
171 gdp
->bg_used_dirs_count
= cpu_to_le16(
172 le16_to_cpu(gdp
->bg_used_dirs_count
) - 1);
173 spin_unlock(sb_bgl_lock(sbi
, block_group
));
174 percpu_counter_inc(&sbi
->s_freeinodes_counter
);
176 percpu_counter_dec(&sbi
->s_dirs_counter
);
179 BUFFER_TRACE(bh2
, "call ext3_journal_dirty_metadata");
180 err
= ext3_journal_dirty_metadata(handle
, bh2
);
181 if (!fatal
) fatal
= err
;
183 BUFFER_TRACE(bitmap_bh
, "call ext3_journal_dirty_metadata");
184 err
= ext3_journal_dirty_metadata(handle
, bitmap_bh
);
190 ext3_std_error(sb
, fatal
);
194 * There are two policies for allocating an inode. If the new inode is
195 * a directory, then a forward search is made for a block group with both
196 * free space and a low directory-to-inode ratio; if that fails, then of
197 * the groups with above-average free space, that group with the fewest
198 * directories already is chosen.
200 * For other inodes, search forward from the parent directory\'s block
201 * group to find a free inode.
203 static int find_group_dir(struct super_block
*sb
, struct inode
*parent
)
205 int ngroups
= EXT3_SB(sb
)->s_groups_count
;
207 struct ext3_group_desc
*desc
, *best_desc
= NULL
;
208 struct buffer_head
*bh
;
209 int group
, best_group
= -1;
211 freei
= percpu_counter_read_positive(&EXT3_SB(sb
)->s_freeinodes_counter
);
212 avefreei
= freei
/ ngroups
;
214 for (group
= 0; group
< ngroups
; group
++) {
215 desc
= ext3_get_group_desc (sb
, group
, &bh
);
216 if (!desc
|| !desc
->bg_free_inodes_count
)
218 if (le16_to_cpu(desc
->bg_free_inodes_count
) < avefreei
)
221 (le16_to_cpu(desc
->bg_free_blocks_count
) >
222 le16_to_cpu(best_desc
->bg_free_blocks_count
))) {
231 * Orlov's allocator for directories.
233 * We always try to spread first-level directories.
235 * If there are blockgroups with both free inodes and free blocks counts
236 * not worse than average we return one with smallest directory count.
237 * Otherwise we simply return a random group.
239 * For the rest rules look so:
241 * It's OK to put directory into a group unless
242 * it has too many directories already (max_dirs) or
243 * it has too few free inodes left (min_inodes) or
244 * it has too few free blocks left (min_blocks) or
245 * it's already running too large debt (max_debt).
246 * Parent's group is prefered, if it doesn't satisfy these
247 * conditions we search cyclically through the rest. If none
248 * of the groups look good we just look for a group with more
249 * free inodes than average (starting at parent's group).
251 * Debt is incremented each time we allocate a directory and decremented
252 * when we allocate an inode, within 0--255.
255 #define INODE_COST 64
256 #define BLOCK_COST 256
258 static int find_group_orlov(struct super_block
*sb
, struct inode
*parent
)
260 int parent_group
= EXT3_I(parent
)->i_block_group
;
261 struct ext3_sb_info
*sbi
= EXT3_SB(sb
);
262 struct ext3_super_block
*es
= sbi
->s_es
;
263 int ngroups
= sbi
->s_groups_count
;
264 int inodes_per_group
= EXT3_INODES_PER_GROUP(sb
);
267 int blocks_per_dir
, ndirs
;
268 int max_debt
, max_dirs
, min_blocks
, min_inodes
;
270 struct ext3_group_desc
*desc
;
271 struct buffer_head
*bh
;
273 freei
= percpu_counter_read_positive(&sbi
->s_freeinodes_counter
);
274 avefreei
= freei
/ ngroups
;
275 freeb
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
276 avefreeb
= freeb
/ ngroups
;
277 ndirs
= percpu_counter_read_positive(&sbi
->s_dirs_counter
);
279 if ((parent
== sb
->s_root
->d_inode
) ||
280 (EXT3_I(parent
)->i_flags
& EXT3_TOPDIR_FL
)) {
281 int best_ndir
= inodes_per_group
;
284 get_random_bytes(&group
, sizeof(group
));
285 parent_group
= (unsigned)group
% ngroups
;
286 for (i
= 0; i
< ngroups
; i
++) {
287 group
= (parent_group
+ i
) % ngroups
;
288 desc
= ext3_get_group_desc (sb
, group
, &bh
);
289 if (!desc
|| !desc
->bg_free_inodes_count
)
291 if (le16_to_cpu(desc
->bg_used_dirs_count
) >= best_ndir
)
293 if (le16_to_cpu(desc
->bg_free_inodes_count
) < avefreei
)
295 if (le16_to_cpu(desc
->bg_free_blocks_count
) < avefreeb
)
298 best_ndir
= le16_to_cpu(desc
->bg_used_dirs_count
);
305 blocks_per_dir
= (le32_to_cpu(es
->s_blocks_count
) - freeb
) / ndirs
;
307 max_dirs
= ndirs
/ ngroups
+ inodes_per_group
/ 16;
308 min_inodes
= avefreei
- inodes_per_group
/ 4;
309 min_blocks
= avefreeb
- EXT3_BLOCKS_PER_GROUP(sb
) / 4;
311 max_debt
= EXT3_BLOCKS_PER_GROUP(sb
) / max(blocks_per_dir
, BLOCK_COST
);
312 if (max_debt
* INODE_COST
> inodes_per_group
)
313 max_debt
= inodes_per_group
/ INODE_COST
;
319 for (i
= 0; i
< ngroups
; i
++) {
320 group
= (parent_group
+ i
) % ngroups
;
321 desc
= ext3_get_group_desc (sb
, group
, &bh
);
322 if (!desc
|| !desc
->bg_free_inodes_count
)
324 if (le16_to_cpu(desc
->bg_used_dirs_count
) >= max_dirs
)
326 if (le16_to_cpu(desc
->bg_free_inodes_count
) < min_inodes
)
328 if (le16_to_cpu(desc
->bg_free_blocks_count
) < min_blocks
)
334 for (i
= 0; i
< ngroups
; i
++) {
335 group
= (parent_group
+ i
) % ngroups
;
336 desc
= ext3_get_group_desc (sb
, group
, &bh
);
337 if (!desc
|| !desc
->bg_free_inodes_count
)
339 if (le16_to_cpu(desc
->bg_free_inodes_count
) >= avefreei
)
345 * The free-inodes counter is approximate, and for really small
346 * filesystems the above test can fail to find any blockgroups
355 static int find_group_other(struct super_block
*sb
, struct inode
*parent
)
357 int parent_group
= EXT3_I(parent
)->i_block_group
;
358 int ngroups
= EXT3_SB(sb
)->s_groups_count
;
359 struct ext3_group_desc
*desc
;
360 struct buffer_head
*bh
;
364 * Try to place the inode in its parent directory
366 group
= parent_group
;
367 desc
= ext3_get_group_desc (sb
, group
, &bh
);
368 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
) &&
369 le16_to_cpu(desc
->bg_free_blocks_count
))
373 * We're going to place this inode in a different blockgroup from its
374 * parent. We want to cause files in a common directory to all land in
375 * the same blockgroup. But we want files which are in a different
376 * directory which shares a blockgroup with our parent to land in a
377 * different blockgroup.
379 * So add our directory's i_ino into the starting point for the hash.
381 group
= (group
+ parent
->i_ino
) % ngroups
;
384 * Use a quadratic hash to find a group with a free inode and some free
387 for (i
= 1; i
< ngroups
; i
<<= 1) {
389 if (group
>= ngroups
)
391 desc
= ext3_get_group_desc (sb
, group
, &bh
);
392 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
) &&
393 le16_to_cpu(desc
->bg_free_blocks_count
))
398 * That failed: try linear search for a free inode, even if that group
399 * has no free blocks.
401 group
= parent_group
;
402 for (i
= 0; i
< ngroups
; i
++) {
403 if (++group
>= ngroups
)
405 desc
= ext3_get_group_desc (sb
, group
, &bh
);
406 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
))
414 * There are two policies for allocating an inode. If the new inode is
415 * a directory, then a forward search is made for a block group with both
416 * free space and a low directory-to-inode ratio; if that fails, then of
417 * the groups with above-average free space, that group with the fewest
418 * directories already is chosen.
420 * For other inodes, search forward from the parent directory's block
421 * group to find a free inode.
423 struct inode
*ext3_new_inode(handle_t
*handle
, struct inode
* dir
, int mode
)
425 struct super_block
*sb
;
426 struct buffer_head
*bitmap_bh
= NULL
;
427 struct buffer_head
*bh2
;
429 unsigned long ino
= 0;
430 struct inode
* inode
;
431 struct ext3_group_desc
* gdp
= NULL
;
432 struct ext3_super_block
* es
;
433 struct ext3_inode_info
*ei
;
434 struct ext3_sb_info
*sbi
;
439 /* Cannot create files in a deleted directory */
440 if (!dir
|| !dir
->i_nlink
)
441 return ERR_PTR(-EPERM
);
444 inode
= new_inode(sb
);
446 return ERR_PTR(-ENOMEM
);
452 if (test_opt (sb
, OLDALLOC
))
453 group
= find_group_dir(sb
, dir
);
455 group
= find_group_orlov(sb
, dir
);
457 group
= find_group_other(sb
, dir
);
463 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
466 gdp
= ext3_get_group_desc(sb
, group
, &bh2
);
471 bitmap_bh
= read_inode_bitmap(sb
, group
);
477 repeat_in_this_group
:
478 ino
= ext3_find_next_zero_bit((unsigned long *)
479 bitmap_bh
->b_data
, EXT3_INODES_PER_GROUP(sb
), ino
);
480 if (ino
< EXT3_INODES_PER_GROUP(sb
)) {
482 BUFFER_TRACE(bitmap_bh
, "get_write_access");
483 err
= ext3_journal_get_write_access(handle
, bitmap_bh
);
487 if (!ext3_set_bit_atomic(sb_bgl_lock(sbi
, group
),
488 ino
, bitmap_bh
->b_data
)) {
490 BUFFER_TRACE(bitmap_bh
,
491 "call ext3_journal_dirty_metadata");
492 err
= ext3_journal_dirty_metadata(handle
,
499 journal_release_buffer(handle
, bitmap_bh
);
501 if (++ino
< EXT3_INODES_PER_GROUP(sb
))
502 goto repeat_in_this_group
;
506 * This case is possible in concurrent environment. It is very
507 * rare. We cannot repeat the find_group_xxx() call because
508 * that will simply return the same blockgroup, because the
509 * group descriptor metadata has not yet been updated.
510 * So we just go onto the next blockgroup.
512 if (++group
== sbi
->s_groups_count
)
519 ino
+= group
* EXT3_INODES_PER_GROUP(sb
) + 1;
520 if (ino
< EXT3_FIRST_INO(sb
) || ino
> le32_to_cpu(es
->s_inodes_count
)) {
521 ext3_error (sb
, "ext3_new_inode",
522 "reserved inode or inode > inodes count - "
523 "block_group = %d, inode=%lu", group
, ino
);
528 BUFFER_TRACE(bh2
, "get_write_access");
529 err
= ext3_journal_get_write_access(handle
, bh2
);
531 spin_lock(sb_bgl_lock(sbi
, group
));
532 gdp
->bg_free_inodes_count
=
533 cpu_to_le16(le16_to_cpu(gdp
->bg_free_inodes_count
) - 1);
535 gdp
->bg_used_dirs_count
=
536 cpu_to_le16(le16_to_cpu(gdp
->bg_used_dirs_count
) + 1);
538 spin_unlock(sb_bgl_lock(sbi
, group
));
539 BUFFER_TRACE(bh2
, "call ext3_journal_dirty_metadata");
540 err
= ext3_journal_dirty_metadata(handle
, bh2
);
543 percpu_counter_dec(&sbi
->s_freeinodes_counter
);
545 percpu_counter_inc(&sbi
->s_dirs_counter
);
548 inode
->i_uid
= current
->fsuid
;
549 if (test_opt (sb
, GRPID
))
550 inode
->i_gid
= dir
->i_gid
;
551 else if (dir
->i_mode
& S_ISGID
) {
552 inode
->i_gid
= dir
->i_gid
;
556 inode
->i_gid
= current
->fsgid
;
557 inode
->i_mode
= mode
;
560 /* This is the optimal IO size (for stat), not the fs block size */
561 inode
->i_blksize
= PAGE_SIZE
;
563 inode
->i_mtime
= inode
->i_atime
= inode
->i_ctime
= CURRENT_TIME_SEC
;
565 memset(ei
->i_data
, 0, sizeof(ei
->i_data
));
566 ei
->i_dir_start_lookup
= 0;
569 ei
->i_flags
= EXT3_I(dir
)->i_flags
& ~EXT3_INDEX_FL
;
571 ei
->i_flags
&= ~(EXT3_IMMUTABLE_FL
|EXT3_APPEND_FL
);
572 /* dirsync only applies to directories */
574 ei
->i_flags
&= ~EXT3_DIRSYNC_FL
;
575 #ifdef EXT3_FRAGMENTS
583 ei
->i_block_alloc_info
= NULL
;
584 ei
->i_block_group
= group
;
586 ext3_set_inode_flags(inode
);
587 if (IS_DIRSYNC(inode
))
589 insert_inode_hash(inode
);
590 spin_lock(&sbi
->s_next_gen_lock
);
591 inode
->i_generation
= sbi
->s_next_generation
++;
592 spin_unlock(&sbi
->s_next_gen_lock
);
594 ei
->i_state
= EXT3_STATE_NEW
;
596 (EXT3_INODE_SIZE(inode
->i_sb
) > EXT3_GOOD_OLD_INODE_SIZE
) ?
597 sizeof(struct ext3_inode
) - EXT3_GOOD_OLD_INODE_SIZE
: 0;
600 if(DQUOT_ALLOC_INODE(inode
)) {
605 err
= ext3_init_acl(handle
, inode
, dir
);
609 err
= ext3_init_security(handle
,inode
, dir
);
613 err
= ext3_mark_inode_dirty(handle
, inode
);
615 ext3_std_error(sb
, err
);
619 ext3_debug("allocating inode %lu\n", inode
->i_ino
);
622 ext3_std_error(sb
, err
);
631 DQUOT_FREE_INODE(inode
);
635 inode
->i_flags
|= S_NOQUOTA
;
642 /* Verify that we are loading a valid orphan from disk */
643 struct inode
*ext3_orphan_get(struct super_block
*sb
, unsigned long ino
)
645 unsigned long max_ino
= le32_to_cpu(EXT3_SB(sb
)->s_es
->s_inodes_count
);
646 unsigned long block_group
;
648 struct buffer_head
*bitmap_bh
= NULL
;
649 struct inode
*inode
= NULL
;
651 /* Error cases - e2fsck has already cleaned up for us */
653 ext3_warning(sb
, __FUNCTION__
,
654 "bad orphan ino %lu! e2fsck was run?\n", ino
);
658 block_group
= (ino
- 1) / EXT3_INODES_PER_GROUP(sb
);
659 bit
= (ino
- 1) % EXT3_INODES_PER_GROUP(sb
);
660 bitmap_bh
= read_inode_bitmap(sb
, block_group
);
662 ext3_warning(sb
, __FUNCTION__
,
663 "inode bitmap error for orphan %lu\n", ino
);
667 /* Having the inode bit set should be a 100% indicator that this
668 * is a valid orphan (no e2fsck run on fs). Orphans also include
669 * inodes that were being truncated, so we can't check i_nlink==0.
671 if (!ext3_test_bit(bit
, bitmap_bh
->b_data
) ||
672 !(inode
= iget(sb
, ino
)) || is_bad_inode(inode
) ||
673 NEXT_ORPHAN(inode
) > max_ino
) {
674 ext3_warning(sb
, __FUNCTION__
,
675 "bad orphan inode %lu! e2fsck was run?\n", ino
);
676 printk(KERN_NOTICE
"ext3_test_bit(bit=%d, block=%llu) = %d\n",
677 bit
, (unsigned long long)bitmap_bh
->b_blocknr
,
678 ext3_test_bit(bit
, bitmap_bh
->b_data
));
679 printk(KERN_NOTICE
"inode=%p\n", inode
);
681 printk(KERN_NOTICE
"is_bad_inode(inode)=%d\n",
682 is_bad_inode(inode
));
683 printk(KERN_NOTICE
"NEXT_ORPHAN(inode)=%u\n",
685 printk(KERN_NOTICE
"max_ino=%lu\n", max_ino
);
687 /* Avoid freeing blocks if we got a bad deleted inode */
688 if (inode
&& inode
->i_nlink
== 0)
698 unsigned long ext3_count_free_inodes (struct super_block
* sb
)
700 unsigned long desc_count
;
701 struct ext3_group_desc
*gdp
;
704 struct ext3_super_block
*es
;
705 unsigned long bitmap_count
, x
;
706 struct buffer_head
*bitmap_bh
= NULL
;
708 es
= EXT3_SB(sb
)->s_es
;
712 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
713 gdp
= ext3_get_group_desc (sb
, i
, NULL
);
716 desc_count
+= le16_to_cpu(gdp
->bg_free_inodes_count
);
718 bitmap_bh
= read_inode_bitmap(sb
, i
);
722 x
= ext3_count_free(bitmap_bh
, EXT3_INODES_PER_GROUP(sb
) / 8);
723 printk("group %d: stored = %d, counted = %lu\n",
724 i
, le16_to_cpu(gdp
->bg_free_inodes_count
), x
);
728 printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
729 le32_to_cpu(es
->s_free_inodes_count
), desc_count
, bitmap_count
);
733 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
734 gdp
= ext3_get_group_desc (sb
, i
, NULL
);
737 desc_count
+= le16_to_cpu(gdp
->bg_free_inodes_count
);
744 /* Called at mount-time, super-block is locked */
745 unsigned long ext3_count_dirs (struct super_block
* sb
)
747 unsigned long count
= 0;
750 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
751 struct ext3_group_desc
*gdp
= ext3_get_group_desc (sb
, i
, NULL
);
754 count
+= le16_to_cpu(gdp
->bg_used_dirs_count
);