1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/ext4/balloc.c
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
10 * Enhanced block allocation by 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>
16 #include <linux/capability.h>
18 #include <linux/quotaops.h>
19 #include <linux/buffer_head.h>
21 #include "ext4_jbd2.h"
24 #include <trace/events/ext4.h>
26 static unsigned ext4_num_base_meta_clusters(struct super_block
*sb
,
27 ext4_group_t block_group
);
29 * balloc.c contains the blocks allocation and deallocation routines
33 * Calculate block group number for a given block number
35 ext4_group_t
ext4_get_group_number(struct super_block
*sb
,
40 if (test_opt2(sb
, STD_GROUP_SIZE
))
42 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
)) >>
43 (EXT4_BLOCK_SIZE_BITS(sb
) + EXT4_CLUSTER_BITS(sb
) + 3);
45 ext4_get_group_no_and_offset(sb
, block
, &group
, NULL
);
50 * Calculate the block group number and offset into the block/cluster
51 * allocation bitmap, given a block number
53 void ext4_get_group_no_and_offset(struct super_block
*sb
, ext4_fsblk_t blocknr
,
54 ext4_group_t
*blockgrpp
, ext4_grpblk_t
*offsetp
)
56 struct ext4_super_block
*es
= EXT4_SB(sb
)->s_es
;
59 blocknr
= blocknr
- le32_to_cpu(es
->s_first_data_block
);
60 offset
= do_div(blocknr
, EXT4_BLOCKS_PER_GROUP(sb
)) >>
61 EXT4_SB(sb
)->s_cluster_bits
;
70 * Check whether the 'block' lives within the 'block_group'. Returns 1 if so
73 static inline int ext4_block_in_group(struct super_block
*sb
,
75 ext4_group_t block_group
)
77 ext4_group_t actual_group
;
79 actual_group
= ext4_get_group_number(sb
, block
);
80 return (actual_group
== block_group
) ? 1 : 0;
83 /* Return the number of clusters used for file system metadata; this
84 * represents the overhead needed by the file system.
86 static unsigned ext4_num_overhead_clusters(struct super_block
*sb
,
87 ext4_group_t block_group
,
88 struct ext4_group_desc
*gdp
)
90 unsigned num_clusters
;
91 int block_cluster
= -1, inode_cluster
= -1, itbl_cluster
= -1, i
, c
;
92 ext4_fsblk_t start
= ext4_group_first_block_no(sb
, block_group
);
93 ext4_fsblk_t itbl_blk
;
94 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
96 /* This is the number of clusters used by the superblock,
97 * block group descriptors, and reserved block group
98 * descriptor blocks */
99 num_clusters
= ext4_num_base_meta_clusters(sb
, block_group
);
102 * For the allocation bitmaps and inode table, we first need
103 * to check to see if the block is in the block group. If it
104 * is, then check to see if the cluster is already accounted
105 * for in the clusters used for the base metadata cluster, or
106 * if we can increment the base metadata cluster to include
107 * that block. Otherwise, we will have to track the cluster
108 * used for the allocation bitmap or inode table explicitly.
109 * Normally all of these blocks are contiguous, so the special
110 * case handling shouldn't be necessary except for *very*
111 * unusual file system layouts.
113 if (ext4_block_in_group(sb
, ext4_block_bitmap(sb
, gdp
), block_group
)) {
114 block_cluster
= EXT4_B2C(sbi
,
115 ext4_block_bitmap(sb
, gdp
) - start
);
116 if (block_cluster
< num_clusters
)
118 else if (block_cluster
== num_clusters
) {
124 if (ext4_block_in_group(sb
, ext4_inode_bitmap(sb
, gdp
), block_group
)) {
125 inode_cluster
= EXT4_B2C(sbi
,
126 ext4_inode_bitmap(sb
, gdp
) - start
);
127 if (inode_cluster
< num_clusters
)
129 else if (inode_cluster
== num_clusters
) {
135 itbl_blk
= ext4_inode_table(sb
, gdp
);
136 for (i
= 0; i
< sbi
->s_itb_per_group
; i
++) {
137 if (ext4_block_in_group(sb
, itbl_blk
+ i
, block_group
)) {
138 c
= EXT4_B2C(sbi
, itbl_blk
+ i
- start
);
139 if ((c
< num_clusters
) || (c
== inode_cluster
) ||
140 (c
== block_cluster
) || (c
== itbl_cluster
))
142 if (c
== num_clusters
) {
151 if (block_cluster
!= -1)
153 if (inode_cluster
!= -1)
159 static unsigned int num_clusters_in_group(struct super_block
*sb
,
160 ext4_group_t block_group
)
164 if (block_group
== ext4_get_groups_count(sb
) - 1) {
166 * Even though mke2fs always initializes the first and
167 * last group, just in case some other tool was used,
168 * we need to make sure we calculate the right free
171 blocks
= ext4_blocks_count(EXT4_SB(sb
)->s_es
) -
172 ext4_group_first_block_no(sb
, block_group
);
174 blocks
= EXT4_BLOCKS_PER_GROUP(sb
);
175 return EXT4_NUM_B2C(EXT4_SB(sb
), blocks
);
178 /* Initializes an uninitialized block bitmap */
179 static int ext4_init_block_bitmap(struct super_block
*sb
,
180 struct buffer_head
*bh
,
181 ext4_group_t block_group
,
182 struct ext4_group_desc
*gdp
)
184 unsigned int bit
, bit_max
;
185 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
186 ext4_fsblk_t start
, tmp
;
188 J_ASSERT_BH(bh
, buffer_locked(bh
));
190 /* If checksum is bad mark all blocks used to prevent allocation
191 * essentially implementing a per-group read-only flag. */
192 if (!ext4_group_desc_csum_verify(sb
, block_group
, gdp
)) {
193 ext4_mark_group_bitmap_corrupted(sb
, block_group
,
194 EXT4_GROUP_INFO_BBITMAP_CORRUPT
|
195 EXT4_GROUP_INFO_IBITMAP_CORRUPT
);
198 memset(bh
->b_data
, 0, sb
->s_blocksize
);
200 bit_max
= ext4_num_base_meta_clusters(sb
, block_group
);
201 if ((bit_max
>> 3) >= bh
->b_size
)
202 return -EFSCORRUPTED
;
204 for (bit
= 0; bit
< bit_max
; bit
++)
205 ext4_set_bit(bit
, bh
->b_data
);
207 start
= ext4_group_first_block_no(sb
, block_group
);
209 /* Set bits for block and inode bitmaps, and inode table */
210 tmp
= ext4_block_bitmap(sb
, gdp
);
211 if (ext4_block_in_group(sb
, tmp
, block_group
))
212 ext4_set_bit(EXT4_B2C(sbi
, tmp
- start
), bh
->b_data
);
214 tmp
= ext4_inode_bitmap(sb
, gdp
);
215 if (ext4_block_in_group(sb
, tmp
, block_group
))
216 ext4_set_bit(EXT4_B2C(sbi
, tmp
- start
), bh
->b_data
);
218 tmp
= ext4_inode_table(sb
, gdp
);
219 for (; tmp
< ext4_inode_table(sb
, gdp
) +
220 sbi
->s_itb_per_group
; tmp
++) {
221 if (ext4_block_in_group(sb
, tmp
, block_group
))
222 ext4_set_bit(EXT4_B2C(sbi
, tmp
- start
), bh
->b_data
);
226 * Also if the number of blocks within the group is less than
227 * the blocksize * 8 ( which is the size of bitmap ), set rest
228 * of the block bitmap to 1
230 ext4_mark_bitmap_end(num_clusters_in_group(sb
, block_group
),
231 sb
->s_blocksize
* 8, bh
->b_data
);
235 /* Return the number of free blocks in a block group. It is used when
236 * the block bitmap is uninitialized, so we can't just count the bits
238 unsigned ext4_free_clusters_after_init(struct super_block
*sb
,
239 ext4_group_t block_group
,
240 struct ext4_group_desc
*gdp
)
242 return num_clusters_in_group(sb
, block_group
) -
243 ext4_num_overhead_clusters(sb
, block_group
, gdp
);
247 * The free blocks are managed by bitmaps. A file system contains several
248 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
249 * block for inodes, N blocks for the inode table and data blocks.
251 * The file system contains group descriptors which are located after the
252 * super block. Each descriptor contains the number of the bitmap block and
253 * the free blocks count in the block. The descriptors are loaded in memory
254 * when a file system is mounted (see ext4_fill_super).
258 * ext4_get_group_desc() -- load group descriptor from disk
260 * @block_group: given block group
261 * @bh: pointer to the buffer head to store the block
264 struct ext4_group_desc
* ext4_get_group_desc(struct super_block
*sb
,
265 ext4_group_t block_group
,
266 struct buffer_head
**bh
)
268 unsigned int group_desc
;
270 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
271 struct ext4_group_desc
*desc
;
272 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
274 if (block_group
>= ngroups
) {
275 ext4_error(sb
, "block_group >= groups_count - block_group = %u,"
276 " groups_count = %u", block_group
, ngroups
);
281 group_desc
= block_group
>> EXT4_DESC_PER_BLOCK_BITS(sb
);
282 offset
= block_group
& (EXT4_DESC_PER_BLOCK(sb
) - 1);
283 if (!sbi
->s_group_desc
[group_desc
]) {
284 ext4_error(sb
, "Group descriptor not loaded - "
285 "block_group = %u, group_desc = %u, desc = %u",
286 block_group
, group_desc
, offset
);
290 desc
= (struct ext4_group_desc
*)(
291 (__u8
*)sbi
->s_group_desc
[group_desc
]->b_data
+
292 offset
* EXT4_DESC_SIZE(sb
));
294 *bh
= sbi
->s_group_desc
[group_desc
];
299 * Return the block number which was discovered to be invalid, or 0 if
300 * the block bitmap is valid.
302 static ext4_fsblk_t
ext4_valid_block_bitmap(struct super_block
*sb
,
303 struct ext4_group_desc
*desc
,
304 ext4_group_t block_group
,
305 struct buffer_head
*bh
)
307 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
308 ext4_grpblk_t offset
;
309 ext4_grpblk_t next_zero_bit
;
310 ext4_grpblk_t max_bit
= EXT4_CLUSTERS_PER_GROUP(sb
);
312 ext4_fsblk_t group_first_block
;
314 if (ext4_has_feature_flex_bg(sb
)) {
315 /* with FLEX_BG, the inode/block bitmaps and itable
316 * blocks may not be in the group at all
317 * so the bitmap validation will be skipped for those groups
318 * or it has to also read the block group where the bitmaps
319 * are located to verify they are set.
323 group_first_block
= ext4_group_first_block_no(sb
, block_group
);
325 /* check whether block bitmap block number is set */
326 blk
= ext4_block_bitmap(sb
, desc
);
327 offset
= blk
- group_first_block
;
328 if (offset
< 0 || EXT4_B2C(sbi
, offset
) >= max_bit
||
329 !ext4_test_bit(EXT4_B2C(sbi
, offset
), bh
->b_data
))
330 /* bad block bitmap */
333 /* check whether the inode bitmap block number is set */
334 blk
= ext4_inode_bitmap(sb
, desc
);
335 offset
= blk
- group_first_block
;
336 if (offset
< 0 || EXT4_B2C(sbi
, offset
) >= max_bit
||
337 !ext4_test_bit(EXT4_B2C(sbi
, offset
), bh
->b_data
))
338 /* bad block bitmap */
341 /* check whether the inode table block number is set */
342 blk
= ext4_inode_table(sb
, desc
);
343 offset
= blk
- group_first_block
;
344 if (offset
< 0 || EXT4_B2C(sbi
, offset
) >= max_bit
||
345 EXT4_B2C(sbi
, offset
+ sbi
->s_itb_per_group
) >= max_bit
)
347 next_zero_bit
= ext4_find_next_zero_bit(bh
->b_data
,
348 EXT4_B2C(sbi
, offset
+ sbi
->s_itb_per_group
),
349 EXT4_B2C(sbi
, offset
));
351 EXT4_B2C(sbi
, offset
+ sbi
->s_itb_per_group
))
352 /* bad bitmap for inode tables */
357 static int ext4_validate_block_bitmap(struct super_block
*sb
,
358 struct ext4_group_desc
*desc
,
359 ext4_group_t block_group
,
360 struct buffer_head
*bh
)
363 struct ext4_group_info
*grp
= ext4_get_group_info(sb
, block_group
);
365 if (buffer_verified(bh
))
367 if (EXT4_MB_GRP_BBITMAP_CORRUPT(grp
))
368 return -EFSCORRUPTED
;
370 ext4_lock_group(sb
, block_group
);
371 if (buffer_verified(bh
))
373 if (unlikely(!ext4_block_bitmap_csum_verify(sb
, block_group
,
375 ext4_simulate_fail(sb
, EXT4_SIM_BBITMAP_CRC
))) {
376 ext4_unlock_group(sb
, block_group
);
377 ext4_error(sb
, "bg %u: bad block bitmap checksum", block_group
);
378 ext4_mark_group_bitmap_corrupted(sb
, block_group
,
379 EXT4_GROUP_INFO_BBITMAP_CORRUPT
);
382 blk
= ext4_valid_block_bitmap(sb
, desc
, block_group
, bh
);
383 if (unlikely(blk
!= 0)) {
384 ext4_unlock_group(sb
, block_group
);
385 ext4_error(sb
, "bg %u: block %llu: invalid block bitmap",
387 ext4_mark_group_bitmap_corrupted(sb
, block_group
,
388 EXT4_GROUP_INFO_BBITMAP_CORRUPT
);
389 return -EFSCORRUPTED
;
391 set_buffer_verified(bh
);
393 ext4_unlock_group(sb
, block_group
);
398 * ext4_read_block_bitmap_nowait()
400 * @block_group: given block group
402 * Read the bitmap for a given block_group,and validate the
403 * bits for block/inode/inode tables are set in the bitmaps
405 * Return buffer_head on success or NULL in case of failure.
408 ext4_read_block_bitmap_nowait(struct super_block
*sb
, ext4_group_t block_group
)
410 struct ext4_group_desc
*desc
;
411 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
412 struct buffer_head
*bh
;
413 ext4_fsblk_t bitmap_blk
;
416 desc
= ext4_get_group_desc(sb
, block_group
, NULL
);
418 return ERR_PTR(-EFSCORRUPTED
);
419 bitmap_blk
= ext4_block_bitmap(sb
, desc
);
420 if ((bitmap_blk
<= le32_to_cpu(sbi
->s_es
->s_first_data_block
)) ||
421 (bitmap_blk
>= ext4_blocks_count(sbi
->s_es
))) {
422 ext4_error(sb
, "Invalid block bitmap block %llu in "
423 "block_group %u", bitmap_blk
, block_group
);
424 ext4_mark_group_bitmap_corrupted(sb
, block_group
,
425 EXT4_GROUP_INFO_BBITMAP_CORRUPT
);
426 return ERR_PTR(-EFSCORRUPTED
);
428 bh
= sb_getblk(sb
, bitmap_blk
);
430 ext4_warning(sb
, "Cannot get buffer for block bitmap - "
431 "block_group = %u, block_bitmap = %llu",
432 block_group
, bitmap_blk
);
433 return ERR_PTR(-ENOMEM
);
436 if (bitmap_uptodate(bh
))
440 if (bitmap_uptodate(bh
)) {
444 ext4_lock_group(sb
, block_group
);
445 if (ext4_has_group_desc_csum(sb
) &&
446 (desc
->bg_flags
& cpu_to_le16(EXT4_BG_BLOCK_UNINIT
))) {
447 if (block_group
== 0) {
448 ext4_unlock_group(sb
, block_group
);
450 ext4_error(sb
, "Block bitmap for bg 0 marked "
455 err
= ext4_init_block_bitmap(sb
, bh
, block_group
, desc
);
456 set_bitmap_uptodate(bh
);
457 set_buffer_uptodate(bh
);
458 set_buffer_verified(bh
);
459 ext4_unlock_group(sb
, block_group
);
462 ext4_error(sb
, "Failed to init block bitmap for group "
463 "%u: %d", block_group
, err
);
468 ext4_unlock_group(sb
, block_group
);
469 if (buffer_uptodate(bh
)) {
471 * if not uninit if bh is uptodate,
472 * bitmap is also uptodate
474 set_bitmap_uptodate(bh
);
479 * submit the buffer_head for reading
482 trace_ext4_read_block_bitmap_load(sb
, block_group
);
483 bh
->b_end_io
= ext4_end_bitmap_read
;
485 submit_bh(REQ_OP_READ
, REQ_META
| REQ_PRIO
, bh
);
488 err
= ext4_validate_block_bitmap(sb
, desc
, block_group
, bh
);
497 /* Returns 0 on success, 1 on error */
498 int ext4_wait_block_bitmap(struct super_block
*sb
, ext4_group_t block_group
,
499 struct buffer_head
*bh
)
501 struct ext4_group_desc
*desc
;
505 desc
= ext4_get_group_desc(sb
, block_group
, NULL
);
507 return -EFSCORRUPTED
;
509 ext4_simulate_fail_bh(sb
, bh
, EXT4_SIM_BBITMAP_EIO
);
510 if (!buffer_uptodate(bh
)) {
511 ext4_set_errno(sb
, EIO
);
512 ext4_error(sb
, "Cannot read block bitmap - "
513 "block_group = %u, block_bitmap = %llu",
514 block_group
, (unsigned long long) bh
->b_blocknr
);
515 ext4_mark_group_bitmap_corrupted(sb
, block_group
,
516 EXT4_GROUP_INFO_BBITMAP_CORRUPT
);
519 clear_buffer_new(bh
);
520 /* Panic or remount fs read-only if block bitmap is invalid */
521 return ext4_validate_block_bitmap(sb
, desc
, block_group
, bh
);
525 ext4_read_block_bitmap(struct super_block
*sb
, ext4_group_t block_group
)
527 struct buffer_head
*bh
;
530 bh
= ext4_read_block_bitmap_nowait(sb
, block_group
);
533 err
= ext4_wait_block_bitmap(sb
, block_group
, bh
);
542 * ext4_has_free_clusters()
543 * @sbi: in-core super block structure.
544 * @nclusters: number of needed blocks
545 * @flags: flags from ext4_mb_new_blocks()
547 * Check if filesystem has nclusters free & available for allocation.
548 * On success return 1, return 0 on failure.
550 static int ext4_has_free_clusters(struct ext4_sb_info
*sbi
,
551 s64 nclusters
, unsigned int flags
)
553 s64 free_clusters
, dirty_clusters
, rsv
, resv_clusters
;
554 struct percpu_counter
*fcc
= &sbi
->s_freeclusters_counter
;
555 struct percpu_counter
*dcc
= &sbi
->s_dirtyclusters_counter
;
557 free_clusters
= percpu_counter_read_positive(fcc
);
558 dirty_clusters
= percpu_counter_read_positive(dcc
);
559 resv_clusters
= atomic64_read(&sbi
->s_resv_clusters
);
562 * r_blocks_count should always be multiple of the cluster ratio so
563 * we are safe to do a plane bit shift only.
565 rsv
= (ext4_r_blocks_count(sbi
->s_es
) >> sbi
->s_cluster_bits
) +
568 if (free_clusters
- (nclusters
+ rsv
+ dirty_clusters
) <
569 EXT4_FREECLUSTERS_WATERMARK
) {
570 free_clusters
= percpu_counter_sum_positive(fcc
);
571 dirty_clusters
= percpu_counter_sum_positive(dcc
);
573 /* Check whether we have space after accounting for current
574 * dirty clusters & root reserved clusters.
576 if (free_clusters
>= (rsv
+ nclusters
+ dirty_clusters
))
579 /* Hm, nope. Are (enough) root reserved clusters available? */
580 if (uid_eq(sbi
->s_resuid
, current_fsuid()) ||
581 (!gid_eq(sbi
->s_resgid
, GLOBAL_ROOT_GID
) && in_group_p(sbi
->s_resgid
)) ||
582 capable(CAP_SYS_RESOURCE
) ||
583 (flags
& EXT4_MB_USE_ROOT_BLOCKS
)) {
585 if (free_clusters
>= (nclusters
+ dirty_clusters
+
589 /* No free blocks. Let's see if we can dip into reserved pool */
590 if (flags
& EXT4_MB_USE_RESERVED
) {
591 if (free_clusters
>= (nclusters
+ dirty_clusters
))
598 int ext4_claim_free_clusters(struct ext4_sb_info
*sbi
,
599 s64 nclusters
, unsigned int flags
)
601 if (ext4_has_free_clusters(sbi
, nclusters
, flags
)) {
602 percpu_counter_add(&sbi
->s_dirtyclusters_counter
, nclusters
);
609 * ext4_should_retry_alloc() - check if a block allocation should be retried
611 * @retries: number of attemps has been made
613 * ext4_should_retry_alloc() is called when ENOSPC is returned, and if
614 * it is profitable to retry the operation, this function will wait
615 * for the current or committing transaction to complete, and then
616 * return TRUE. We will only retry once.
618 int ext4_should_retry_alloc(struct super_block
*sb
, int *retries
)
620 if (!ext4_has_free_clusters(EXT4_SB(sb
), 1, 0) ||
622 !EXT4_SB(sb
)->s_journal
)
626 if (EXT4_SB(sb
)->s_mb_free_pending
== 0)
629 jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb
->s_id
);
630 jbd2_journal_force_commit_nested(EXT4_SB(sb
)->s_journal
);
635 * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
637 * @handle: handle to this transaction
639 * @goal: given target block(filesystem wide)
640 * @count: pointer to total number of clusters needed
643 * Return 1st allocated block number on success, *count stores total account
644 * error stores in errp pointer
646 ext4_fsblk_t
ext4_new_meta_blocks(handle_t
*handle
, struct inode
*inode
,
647 ext4_fsblk_t goal
, unsigned int flags
,
648 unsigned long *count
, int *errp
)
650 struct ext4_allocation_request ar
;
653 memset(&ar
, 0, sizeof(ar
));
654 /* Fill with neighbour allocated blocks */
657 ar
.len
= count
? *count
: 1;
660 ret
= ext4_mb_new_blocks(handle
, &ar
, errp
);
664 * Account for the allocated meta blocks. We will never
665 * fail EDQUOT for metdata, but we do account for it.
667 if (!(*errp
) && (flags
& EXT4_MB_DELALLOC_RESERVED
)) {
668 dquot_alloc_block_nofail(inode
,
669 EXT4_C2B(EXT4_SB(inode
->i_sb
), ar
.len
));
675 * ext4_count_free_clusters() -- count filesystem free clusters
678 * Adds up the number of free clusters from each block group.
680 ext4_fsblk_t
ext4_count_free_clusters(struct super_block
*sb
)
682 ext4_fsblk_t desc_count
;
683 struct ext4_group_desc
*gdp
;
685 ext4_group_t ngroups
= ext4_get_groups_count(sb
);
686 struct ext4_group_info
*grp
;
688 struct ext4_super_block
*es
;
689 ext4_fsblk_t bitmap_count
;
691 struct buffer_head
*bitmap_bh
= NULL
;
693 es
= EXT4_SB(sb
)->s_es
;
698 for (i
= 0; i
< ngroups
; i
++) {
699 gdp
= ext4_get_group_desc(sb
, i
, NULL
);
703 if (EXT4_SB(sb
)->s_group_info
)
704 grp
= ext4_get_group_info(sb
, i
);
705 if (!grp
|| !EXT4_MB_GRP_BBITMAP_CORRUPT(grp
))
706 desc_count
+= ext4_free_group_clusters(sb
, gdp
);
708 bitmap_bh
= ext4_read_block_bitmap(sb
, i
);
709 if (IS_ERR(bitmap_bh
)) {
714 x
= ext4_count_free(bitmap_bh
->b_data
,
715 EXT4_CLUSTERS_PER_GROUP(sb
) / 8);
716 printk(KERN_DEBUG
"group %u: stored = %d, counted = %u\n",
717 i
, ext4_free_group_clusters(sb
, gdp
), x
);
721 printk(KERN_DEBUG
"ext4_count_free_clusters: stored = %llu"
722 ", computed = %llu, %llu\n",
723 EXT4_NUM_B2C(EXT4_SB(sb
), ext4_free_blocks_count(es
)),
724 desc_count
, bitmap_count
);
728 for (i
= 0; i
< ngroups
; i
++) {
729 gdp
= ext4_get_group_desc(sb
, i
, NULL
);
733 if (EXT4_SB(sb
)->s_group_info
)
734 grp
= ext4_get_group_info(sb
, i
);
735 if (!grp
|| !EXT4_MB_GRP_BBITMAP_CORRUPT(grp
))
736 desc_count
+= ext4_free_group_clusters(sb
, gdp
);
743 static inline int test_root(ext4_group_t a
, int b
)
757 * ext4_bg_has_super - number of blocks used by the superblock in group
758 * @sb: superblock for filesystem
759 * @group: group number to check
761 * Return the number of blocks used by the superblock (primary or backup)
762 * in this group. Currently this will be only 0 or 1.
764 int ext4_bg_has_super(struct super_block
*sb
, ext4_group_t group
)
766 struct ext4_super_block
*es
= EXT4_SB(sb
)->s_es
;
770 if (ext4_has_feature_sparse_super2(sb
)) {
771 if (group
== le32_to_cpu(es
->s_backup_bgs
[0]) ||
772 group
== le32_to_cpu(es
->s_backup_bgs
[1]))
776 if ((group
<= 1) || !ext4_has_feature_sparse_super(sb
))
780 if (test_root(group
, 3) || (test_root(group
, 5)) ||
787 static unsigned long ext4_bg_num_gdb_meta(struct super_block
*sb
,
790 unsigned long metagroup
= group
/ EXT4_DESC_PER_BLOCK(sb
);
791 ext4_group_t first
= metagroup
* EXT4_DESC_PER_BLOCK(sb
);
792 ext4_group_t last
= first
+ EXT4_DESC_PER_BLOCK(sb
) - 1;
794 if (group
== first
|| group
== first
+ 1 || group
== last
)
799 static unsigned long ext4_bg_num_gdb_nometa(struct super_block
*sb
,
802 if (!ext4_bg_has_super(sb
, group
))
805 if (ext4_has_feature_meta_bg(sb
))
806 return le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_meta_bg
);
808 return EXT4_SB(sb
)->s_gdb_count
;
812 * ext4_bg_num_gdb - number of blocks used by the group table in group
813 * @sb: superblock for filesystem
814 * @group: group number to check
816 * Return the number of blocks used by the group descriptor table
817 * (primary or backup) in this group. In the future there may be a
818 * different number of descriptor blocks in each group.
820 unsigned long ext4_bg_num_gdb(struct super_block
*sb
, ext4_group_t group
)
822 unsigned long first_meta_bg
=
823 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_meta_bg
);
824 unsigned long metagroup
= group
/ EXT4_DESC_PER_BLOCK(sb
);
826 if (!ext4_has_feature_meta_bg(sb
) || metagroup
< first_meta_bg
)
827 return ext4_bg_num_gdb_nometa(sb
, group
);
829 return ext4_bg_num_gdb_meta(sb
,group
);
834 * This function returns the number of file system metadata clusters at
835 * the beginning of a block group, including the reserved gdt blocks.
837 static unsigned ext4_num_base_meta_clusters(struct super_block
*sb
,
838 ext4_group_t block_group
)
840 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
843 /* Check for superblock and gdt backups in this group */
844 num
= ext4_bg_has_super(sb
, block_group
);
846 if (!ext4_has_feature_meta_bg(sb
) ||
847 block_group
< le32_to_cpu(sbi
->s_es
->s_first_meta_bg
) *
848 sbi
->s_desc_per_block
) {
850 num
+= ext4_bg_num_gdb(sb
, block_group
);
851 num
+= le16_to_cpu(sbi
->s_es
->s_reserved_gdt_blocks
);
853 } else { /* For META_BG_BLOCK_GROUPS */
854 num
+= ext4_bg_num_gdb(sb
, block_group
);
856 return EXT4_NUM_B2C(sbi
, num
);
859 * ext4_inode_to_goal_block - return a hint for block allocation
860 * @inode: inode for block allocation
862 * Return the ideal location to start allocating blocks for a
863 * newly created inode.
865 ext4_fsblk_t
ext4_inode_to_goal_block(struct inode
*inode
)
867 struct ext4_inode_info
*ei
= EXT4_I(inode
);
868 ext4_group_t block_group
;
869 ext4_grpblk_t colour
;
870 int flex_size
= ext4_flex_bg_size(EXT4_SB(inode
->i_sb
));
871 ext4_fsblk_t bg_start
;
872 ext4_fsblk_t last_block
;
874 block_group
= ei
->i_block_group
;
875 if (flex_size
>= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
) {
877 * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
878 * block groups per flexgroup, reserve the first block
879 * group for directories and special files. Regular
880 * files will start at the second block group. This
881 * tends to speed up directory access and improves
884 block_group
&= ~(flex_size
-1);
885 if (S_ISREG(inode
->i_mode
))
888 bg_start
= ext4_group_first_block_no(inode
->i_sb
, block_group
);
889 last_block
= ext4_blocks_count(EXT4_SB(inode
->i_sb
)->s_es
) - 1;
892 * If we are doing delayed allocation, we don't need take
893 * colour into account.
895 if (test_opt(inode
->i_sb
, DELALLOC
))
898 if (bg_start
+ EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) <= last_block
)
899 colour
= (current
->pid
% 16) *
900 (EXT4_BLOCKS_PER_GROUP(inode
->i_sb
) / 16);
902 colour
= (current
->pid
% 16) * ((last_block
- bg_start
) / 16);
903 return bg_start
+ colour
;