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>
33 * ialloc.c contains the inodes allocation and deallocation routines
37 * The free inodes are managed by bitmaps. A file system contains several
38 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
39 * block for inodes, N blocks for the inode table and data blocks.
41 * The file system contains group descriptors which are located after the
42 * super block. Each descriptor contains the number of the bitmap block and
43 * the free blocks count in the block.
48 * Read the inode allocation bitmap for a given block_group, reading
49 * into the specified slot in the superblock's bitmap cache.
51 * Return buffer_head of bitmap on success or NULL.
53 static struct buffer_head
*
54 read_inode_bitmap(struct super_block
* sb
, unsigned long block_group
)
56 struct ext3_group_desc
*desc
;
57 struct buffer_head
*bh
= NULL
;
59 desc
= ext3_get_group_desc(sb
, block_group
, NULL
);
63 bh
= sb_bread(sb
, le32_to_cpu(desc
->bg_inode_bitmap
));
65 ext3_error(sb
, "read_inode_bitmap",
66 "Cannot read inode bitmap - "
67 "block_group = %lu, inode_bitmap = %u",
68 block_group
, le32_to_cpu(desc
->bg_inode_bitmap
));
74 * NOTE! When we get the inode, we're the only people
75 * that have access to it, and as such there are no
76 * race conditions we have to worry about. The inode
77 * is not on the hash-lists, and it cannot be reached
78 * through the filesystem because the directory entry
79 * has been deleted earlier.
81 * HOWEVER: we must make sure that we get no aliases,
82 * which means that we have to call "clear_inode()"
83 * _before_ we mark the inode not in use in the inode
84 * bitmaps. Otherwise a newly created file might use
85 * the same inode number (not actually the same pointer
86 * though), and then we'd have two inodes sharing the
87 * same inode number and space on the harddisk.
89 void ext3_free_inode (handle_t
*handle
, struct inode
* inode
)
91 struct super_block
* sb
= inode
->i_sb
;
94 struct buffer_head
*bitmap_bh
= NULL
;
95 struct buffer_head
*bh2
;
96 unsigned long block_group
;
98 struct ext3_group_desc
* gdp
;
99 struct ext3_super_block
* es
;
100 struct ext3_sb_info
*sbi
;
103 if (atomic_read(&inode
->i_count
) > 1) {
104 printk ("ext3_free_inode: inode has count=%d\n",
105 atomic_read(&inode
->i_count
));
108 if (inode
->i_nlink
) {
109 printk ("ext3_free_inode: inode has nlink=%d\n",
114 printk("ext3_free_inode: inode on nonexistent device\n");
120 ext3_debug ("freeing inode %lu\n", ino
);
123 * Note: we must free any quota before locking the superblock,
124 * as writing the quota to disk may need the lock as well.
127 ext3_xattr_delete_inode(handle
, inode
);
128 DQUOT_FREE_INODE(inode
);
131 is_directory
= S_ISDIR(inode
->i_mode
);
133 /* Do this BEFORE marking the inode not in use or returning an error */
136 es
= EXT3_SB(sb
)->s_es
;
137 if (ino
< EXT3_FIRST_INO(sb
) || ino
> le32_to_cpu(es
->s_inodes_count
)) {
138 ext3_error (sb
, "ext3_free_inode",
139 "reserved or nonexistent inode %lu", ino
);
142 block_group
= (ino
- 1) / EXT3_INODES_PER_GROUP(sb
);
143 bit
= (ino
- 1) % EXT3_INODES_PER_GROUP(sb
);
144 bitmap_bh
= read_inode_bitmap(sb
, block_group
);
148 BUFFER_TRACE(bitmap_bh
, "get_write_access");
149 fatal
= ext3_journal_get_write_access(handle
, bitmap_bh
);
153 /* Ok, now we can actually update the inode bitmaps.. */
154 if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi
, block_group
),
155 bit
, bitmap_bh
->b_data
))
156 ext3_error (sb
, "ext3_free_inode",
157 "bit already cleared for inode %lu", ino
);
159 gdp
= ext3_get_group_desc (sb
, block_group
, &bh2
);
161 BUFFER_TRACE(bh2
, "get_write_access");
162 fatal
= ext3_journal_get_write_access(handle
, bh2
);
163 if (fatal
) goto error_return
;
166 spin_lock(sb_bgl_lock(sbi
, block_group
));
167 gdp
->bg_free_inodes_count
= cpu_to_le16(
168 le16_to_cpu(gdp
->bg_free_inodes_count
) + 1);
170 gdp
->bg_used_dirs_count
= cpu_to_le16(
171 le16_to_cpu(gdp
->bg_used_dirs_count
) - 1);
172 spin_unlock(sb_bgl_lock(sbi
, block_group
));
173 percpu_counter_inc(&sbi
->s_freeinodes_counter
);
175 percpu_counter_dec(&sbi
->s_dirs_counter
);
178 BUFFER_TRACE(bh2
, "call ext3_journal_dirty_metadata");
179 err
= ext3_journal_dirty_metadata(handle
, bh2
);
180 if (!fatal
) fatal
= err
;
182 BUFFER_TRACE(bitmap_bh
, "call ext3_journal_dirty_metadata");
183 err
= ext3_journal_dirty_metadata(handle
, bitmap_bh
);
189 ext3_std_error(sb
, fatal
);
193 * There are two policies for allocating an inode. If the new inode is
194 * a directory, then a forward search is made for a block group with both
195 * free space and a low directory-to-inode ratio; if that fails, then of
196 * the groups with above-average free space, that group with the fewest
197 * directories already is chosen.
199 * For other inodes, search forward from the parent directory\'s block
200 * group to find a free inode.
202 static int find_group_dir(struct super_block
*sb
, struct inode
*parent
)
204 int ngroups
= EXT3_SB(sb
)->s_groups_count
;
206 struct ext3_group_desc
*desc
, *best_desc
= NULL
;
207 struct buffer_head
*bh
;
208 int group
, best_group
= -1;
210 freei
= percpu_counter_read_positive(&EXT3_SB(sb
)->s_freeinodes_counter
);
211 avefreei
= freei
/ ngroups
;
213 for (group
= 0; group
< ngroups
; group
++) {
214 desc
= ext3_get_group_desc (sb
, group
, &bh
);
215 if (!desc
|| !desc
->bg_free_inodes_count
)
217 if (le16_to_cpu(desc
->bg_free_inodes_count
) < avefreei
)
220 (le16_to_cpu(desc
->bg_free_blocks_count
) >
221 le16_to_cpu(best_desc
->bg_free_blocks_count
))) {
230 * Orlov's allocator for directories.
232 * We always try to spread first-level directories.
234 * If there are blockgroups with both free inodes and free blocks counts
235 * not worse than average we return one with smallest directory count.
236 * Otherwise we simply return a random group.
238 * For the rest rules look so:
240 * It's OK to put directory into a group unless
241 * it has too many directories already (max_dirs) or
242 * it has too few free inodes left (min_inodes) or
243 * it has too few free blocks left (min_blocks) or
244 * it's already running too large debt (max_debt).
245 * Parent's group is prefered, if it doesn't satisfy these
246 * conditions we search cyclically through the rest. If none
247 * of the groups look good we just look for a group with more
248 * free inodes than average (starting at parent's group).
250 * Debt is incremented each time we allocate a directory and decremented
251 * when we allocate an inode, within 0--255.
254 #define INODE_COST 64
255 #define BLOCK_COST 256
257 static int find_group_orlov(struct super_block
*sb
, struct inode
*parent
)
259 int parent_group
= EXT3_I(parent
)->i_block_group
;
260 struct ext3_sb_info
*sbi
= EXT3_SB(sb
);
261 struct ext3_super_block
*es
= sbi
->s_es
;
262 int ngroups
= sbi
->s_groups_count
;
263 int inodes_per_group
= EXT3_INODES_PER_GROUP(sb
);
266 int blocks_per_dir
, ndirs
;
267 int max_debt
, max_dirs
, min_blocks
, min_inodes
;
269 struct ext3_group_desc
*desc
;
270 struct buffer_head
*bh
;
272 freei
= percpu_counter_read_positive(&sbi
->s_freeinodes_counter
);
273 avefreei
= freei
/ ngroups
;
274 freeb
= percpu_counter_read_positive(&sbi
->s_freeblocks_counter
);
275 avefreeb
= freeb
/ ngroups
;
276 ndirs
= percpu_counter_read_positive(&sbi
->s_dirs_counter
);
278 if ((parent
== sb
->s_root
->d_inode
) ||
279 (EXT3_I(parent
)->i_flags
& EXT3_TOPDIR_FL
)) {
280 int best_ndir
= inodes_per_group
;
283 get_random_bytes(&group
, sizeof(group
));
284 parent_group
= (unsigned)group
% ngroups
;
285 for (i
= 0; i
< ngroups
; i
++) {
286 group
= (parent_group
+ i
) % ngroups
;
287 desc
= ext3_get_group_desc (sb
, group
, &bh
);
288 if (!desc
|| !desc
->bg_free_inodes_count
)
290 if (le16_to_cpu(desc
->bg_used_dirs_count
) >= best_ndir
)
292 if (le16_to_cpu(desc
->bg_free_inodes_count
) < avefreei
)
294 if (le16_to_cpu(desc
->bg_free_blocks_count
) < avefreeb
)
297 best_ndir
= le16_to_cpu(desc
->bg_used_dirs_count
);
304 blocks_per_dir
= (le32_to_cpu(es
->s_blocks_count
) - freeb
) / ndirs
;
306 max_dirs
= ndirs
/ ngroups
+ inodes_per_group
/ 16;
307 min_inodes
= avefreei
- inodes_per_group
/ 4;
308 min_blocks
= avefreeb
- EXT3_BLOCKS_PER_GROUP(sb
) / 4;
310 max_debt
= EXT3_BLOCKS_PER_GROUP(sb
) / max(blocks_per_dir
, BLOCK_COST
);
311 if (max_debt
* INODE_COST
> inodes_per_group
)
312 max_debt
= inodes_per_group
/ INODE_COST
;
318 for (i
= 0; i
< ngroups
; i
++) {
319 group
= (parent_group
+ i
) % ngroups
;
320 desc
= ext3_get_group_desc (sb
, group
, &bh
);
321 if (!desc
|| !desc
->bg_free_inodes_count
)
323 if (le16_to_cpu(desc
->bg_used_dirs_count
) >= max_dirs
)
325 if (le16_to_cpu(desc
->bg_free_inodes_count
) < min_inodes
)
327 if (le16_to_cpu(desc
->bg_free_blocks_count
) < min_blocks
)
333 for (i
= 0; i
< ngroups
; i
++) {
334 group
= (parent_group
+ i
) % ngroups
;
335 desc
= ext3_get_group_desc (sb
, group
, &bh
);
336 if (!desc
|| !desc
->bg_free_inodes_count
)
338 if (le16_to_cpu(desc
->bg_free_inodes_count
) >= avefreei
)
344 * The free-inodes counter is approximate, and for really small
345 * filesystems the above test can fail to find any blockgroups
354 static int find_group_other(struct super_block
*sb
, struct inode
*parent
)
356 int parent_group
= EXT3_I(parent
)->i_block_group
;
357 int ngroups
= EXT3_SB(sb
)->s_groups_count
;
358 struct ext3_group_desc
*desc
;
359 struct buffer_head
*bh
;
363 * Try to place the inode in its parent directory
365 group
= parent_group
;
366 desc
= ext3_get_group_desc (sb
, group
, &bh
);
367 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
) &&
368 le16_to_cpu(desc
->bg_free_blocks_count
))
372 * We're going to place this inode in a different blockgroup from its
373 * parent. We want to cause files in a common directory to all land in
374 * the same blockgroup. But we want files which are in a different
375 * directory which shares a blockgroup with our parent to land in a
376 * different blockgroup.
378 * So add our directory's i_ino into the starting point for the hash.
380 group
= (group
+ parent
->i_ino
) % ngroups
;
383 * Use a quadratic hash to find a group with a free inode and some free
386 for (i
= 1; i
< ngroups
; i
<<= 1) {
388 if (group
>= ngroups
)
390 desc
= ext3_get_group_desc (sb
, group
, &bh
);
391 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
) &&
392 le16_to_cpu(desc
->bg_free_blocks_count
))
397 * That failed: try linear search for a free inode, even if that group
398 * has no free blocks.
400 group
= parent_group
;
401 for (i
= 0; i
< ngroups
; i
++) {
402 if (++group
>= ngroups
)
404 desc
= ext3_get_group_desc (sb
, group
, &bh
);
405 if (desc
&& le16_to_cpu(desc
->bg_free_inodes_count
))
413 * There are two policies for allocating an inode. If the new inode is
414 * a directory, then a forward search is made for a block group with both
415 * free space and a low directory-to-inode ratio; if that fails, then of
416 * the groups with above-average free space, that group with the fewest
417 * directories already is chosen.
419 * For other inodes, search forward from the parent directory's block
420 * group to find a free inode.
422 struct inode
*ext3_new_inode(handle_t
*handle
, struct inode
* dir
, int mode
)
424 struct super_block
*sb
;
425 struct buffer_head
*bitmap_bh
= NULL
;
426 struct buffer_head
*bh2
;
428 unsigned long ino
= 0;
429 struct inode
* inode
;
430 struct ext3_group_desc
* gdp
= NULL
;
431 struct ext3_super_block
* es
;
432 struct ext3_inode_info
*ei
;
433 struct ext3_sb_info
*sbi
;
438 /* Cannot create files in a deleted directory */
439 if (!dir
|| !dir
->i_nlink
)
440 return ERR_PTR(-EPERM
);
443 inode
= new_inode(sb
);
445 return ERR_PTR(-ENOMEM
);
451 if (test_opt (sb
, OLDALLOC
))
452 group
= find_group_dir(sb
, dir
);
454 group
= find_group_orlov(sb
, dir
);
456 group
= find_group_other(sb
, dir
);
462 for (i
= 0; i
< sbi
->s_groups_count
; i
++) {
465 gdp
= ext3_get_group_desc(sb
, group
, &bh2
);
470 bitmap_bh
= read_inode_bitmap(sb
, group
);
476 repeat_in_this_group
:
477 ino
= ext3_find_next_zero_bit((unsigned long *)
478 bitmap_bh
->b_data
, EXT3_INODES_PER_GROUP(sb
), ino
);
479 if (ino
< EXT3_INODES_PER_GROUP(sb
)) {
481 BUFFER_TRACE(bitmap_bh
, "get_write_access");
482 err
= ext3_journal_get_write_access(handle
, bitmap_bh
);
486 if (!ext3_set_bit_atomic(sb_bgl_lock(sbi
, group
),
487 ino
, bitmap_bh
->b_data
)) {
489 BUFFER_TRACE(bitmap_bh
,
490 "call ext3_journal_dirty_metadata");
491 err
= ext3_journal_dirty_metadata(handle
,
498 journal_release_buffer(handle
, bitmap_bh
);
500 if (++ino
< EXT3_INODES_PER_GROUP(sb
))
501 goto repeat_in_this_group
;
505 * This case is possible in concurrent environment. It is very
506 * rare. We cannot repeat the find_group_xxx() call because
507 * that will simply return the same blockgroup, because the
508 * group descriptor metadata has not yet been updated.
509 * So we just go onto the next blockgroup.
511 if (++group
== sbi
->s_groups_count
)
518 ino
+= group
* EXT3_INODES_PER_GROUP(sb
) + 1;
519 if (ino
< EXT3_FIRST_INO(sb
) || ino
> le32_to_cpu(es
->s_inodes_count
)) {
520 ext3_error (sb
, "ext3_new_inode",
521 "reserved inode or inode > inodes count - "
522 "block_group = %d, inode=%lu", group
, ino
);
527 BUFFER_TRACE(bh2
, "get_write_access");
528 err
= ext3_journal_get_write_access(handle
, bh2
);
530 spin_lock(sb_bgl_lock(sbi
, group
));
531 gdp
->bg_free_inodes_count
=
532 cpu_to_le16(le16_to_cpu(gdp
->bg_free_inodes_count
) - 1);
534 gdp
->bg_used_dirs_count
=
535 cpu_to_le16(le16_to_cpu(gdp
->bg_used_dirs_count
) + 1);
537 spin_unlock(sb_bgl_lock(sbi
, group
));
538 BUFFER_TRACE(bh2
, "call ext3_journal_dirty_metadata");
539 err
= ext3_journal_dirty_metadata(handle
, bh2
);
542 percpu_counter_dec(&sbi
->s_freeinodes_counter
);
544 percpu_counter_inc(&sbi
->s_dirs_counter
);
547 inode
->i_uid
= current
->fsuid
;
548 if (test_opt (sb
, GRPID
))
549 inode
->i_gid
= dir
->i_gid
;
550 else if (dir
->i_mode
& S_ISGID
) {
551 inode
->i_gid
= dir
->i_gid
;
555 inode
->i_gid
= current
->fsgid
;
556 inode
->i_mode
= mode
;
559 /* This is the optimal IO size (for stat), not the fs block size */
560 inode
->i_blksize
= PAGE_SIZE
;
562 inode
->i_mtime
= inode
->i_atime
= inode
->i_ctime
= CURRENT_TIME_SEC
;
564 memset(ei
->i_data
, 0, sizeof(ei
->i_data
));
565 ei
->i_dir_start_lookup
= 0;
568 ei
->i_flags
= EXT3_I(dir
)->i_flags
& ~EXT3_INDEX_FL
;
570 ei
->i_flags
&= ~(EXT3_IMMUTABLE_FL
|EXT3_APPEND_FL
);
571 /* dirsync only applies to directories */
573 ei
->i_flags
&= ~EXT3_DIRSYNC_FL
;
574 #ifdef EXT3_FRAGMENTS
582 ei
->i_block_alloc_info
= NULL
;
583 ei
->i_block_group
= group
;
585 ext3_set_inode_flags(inode
);
586 if (IS_DIRSYNC(inode
))
588 insert_inode_hash(inode
);
589 spin_lock(&sbi
->s_next_gen_lock
);
590 inode
->i_generation
= sbi
->s_next_generation
++;
591 spin_unlock(&sbi
->s_next_gen_lock
);
593 ei
->i_state
= EXT3_STATE_NEW
;
595 (EXT3_INODE_SIZE(inode
->i_sb
) > EXT3_GOOD_OLD_INODE_SIZE
) ?
596 sizeof(struct ext3_inode
) - EXT3_GOOD_OLD_INODE_SIZE
: 0;
599 if(DQUOT_ALLOC_INODE(inode
)) {
604 err
= ext3_init_acl(handle
, inode
, dir
);
608 err
= ext3_init_security(handle
,inode
, dir
);
612 err
= ext3_mark_inode_dirty(handle
, inode
);
614 ext3_std_error(sb
, err
);
618 ext3_debug("allocating inode %lu\n", inode
->i_ino
);
621 ext3_std_error(sb
, err
);
630 DQUOT_FREE_INODE(inode
);
634 inode
->i_flags
|= S_NOQUOTA
;
641 /* Verify that we are loading a valid orphan from disk */
642 struct inode
*ext3_orphan_get(struct super_block
*sb
, unsigned long ino
)
644 unsigned long max_ino
= le32_to_cpu(EXT3_SB(sb
)->s_es
->s_inodes_count
);
645 unsigned long block_group
;
647 struct buffer_head
*bitmap_bh
= NULL
;
648 struct inode
*inode
= NULL
;
650 /* Error cases - e2fsck has already cleaned up for us */
652 ext3_warning(sb
, __FUNCTION__
,
653 "bad orphan ino %lu! e2fsck was run?", ino
);
657 block_group
= (ino
- 1) / EXT3_INODES_PER_GROUP(sb
);
658 bit
= (ino
- 1) % EXT3_INODES_PER_GROUP(sb
);
659 bitmap_bh
= read_inode_bitmap(sb
, block_group
);
661 ext3_warning(sb
, __FUNCTION__
,
662 "inode bitmap error for orphan %lu", ino
);
666 /* Having the inode bit set should be a 100% indicator that this
667 * is a valid orphan (no e2fsck run on fs). Orphans also include
668 * inodes that were being truncated, so we can't check i_nlink==0.
670 if (!ext3_test_bit(bit
, bitmap_bh
->b_data
) ||
671 !(inode
= iget(sb
, ino
)) || is_bad_inode(inode
) ||
672 NEXT_ORPHAN(inode
) > max_ino
) {
673 ext3_warning(sb
, __FUNCTION__
,
674 "bad orphan inode %lu! e2fsck was run?", ino
);
675 printk(KERN_NOTICE
"ext3_test_bit(bit=%d, block=%llu) = %d\n",
676 bit
, (unsigned long long)bitmap_bh
->b_blocknr
,
677 ext3_test_bit(bit
, bitmap_bh
->b_data
));
678 printk(KERN_NOTICE
"inode=%p\n", inode
);
680 printk(KERN_NOTICE
"is_bad_inode(inode)=%d\n",
681 is_bad_inode(inode
));
682 printk(KERN_NOTICE
"NEXT_ORPHAN(inode)=%u\n",
684 printk(KERN_NOTICE
"max_ino=%lu\n", max_ino
);
686 /* Avoid freeing blocks if we got a bad deleted inode */
687 if (inode
&& inode
->i_nlink
== 0)
697 unsigned long ext3_count_free_inodes (struct super_block
* sb
)
699 unsigned long desc_count
;
700 struct ext3_group_desc
*gdp
;
703 struct ext3_super_block
*es
;
704 unsigned long bitmap_count
, x
;
705 struct buffer_head
*bitmap_bh
= NULL
;
707 es
= EXT3_SB(sb
)->s_es
;
711 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
712 gdp
= ext3_get_group_desc (sb
, i
, NULL
);
715 desc_count
+= le16_to_cpu(gdp
->bg_free_inodes_count
);
717 bitmap_bh
= read_inode_bitmap(sb
, i
);
721 x
= ext3_count_free(bitmap_bh
, EXT3_INODES_PER_GROUP(sb
) / 8);
722 printk("group %d: stored = %d, counted = %lu\n",
723 i
, le16_to_cpu(gdp
->bg_free_inodes_count
), x
);
727 printk("ext3_count_free_inodes: stored = %u, computed = %lu, %lu\n",
728 le32_to_cpu(es
->s_free_inodes_count
), desc_count
, bitmap_count
);
732 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
733 gdp
= ext3_get_group_desc (sb
, i
, NULL
);
736 desc_count
+= le16_to_cpu(gdp
->bg_free_inodes_count
);
743 /* Called at mount-time, super-block is locked */
744 unsigned long ext3_count_dirs (struct super_block
* sb
)
746 unsigned long count
= 0;
749 for (i
= 0; i
< EXT3_SB(sb
)->s_groups_count
; i
++) {
750 struct ext3_group_desc
*gdp
= ext3_get_group_desc (sb
, i
, NULL
);
753 count
+= le16_to_cpu(gdp
->bg_used_dirs_count
);