Release 4.10 fs/ext4/balloc.c

/*
 *  linux/fs/ext4/balloc.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/time.h>
#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "mballoc.h"

#include <trace/events/ext4.h>

static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
					    ext4_group_t block_group);
/*
 * balloc.c contains the blocks allocation and deallocation routines
 */

/*
 * Calculate block group number for a given block number
 */


ext4_group_t ext4_get_group_number(struct super_block *sb,
				   ext4_fsblk_t block)
{
	ext4_group_t group;

	if (test_opt2(sb, STD_GROUP_SIZE))
		group = (block -
			 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) >>
			(EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
	else
		ext4_get_group_no_and_offset(sb, block, &group, NULL);
	return group;
}

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/*
 * Calculate the block group number and offset into the block/cluster
 * allocation bitmap, given a block number
 */


void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
		ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
	ext4_grpblk_t offset;

	blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
	offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
		EXT4_SB(sb)->s_cluster_bits;
	if (offsetp)
		*offsetp = offset;
	if (blockgrpp)
		*blockgrpp = blocknr;

}

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/*
 * Check whether the 'block' lives within the 'block_group'. Returns 1 if so
 * and 0 otherwise.
 */


static inline int ext4_block_in_group(struct super_block *sb,
				      ext4_fsblk_t block,
				      ext4_group_t block_group)
{
	ext4_group_t actual_group;

	actual_group = ext4_get_group_number(sb, block);
	return (actual_group == block_group) ? 1 : 0;
}

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/* Return the number of clusters used for file system metadata; this
 * represents the overhead needed by the file system.
 */


static unsigned ext4_num_overhead_clusters(struct super_block *sb,
					   ext4_group_t block_group,
					   struct ext4_group_desc *gdp)
{
	unsigned num_clusters;
	int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c;
	ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group);
	ext4_fsblk_t itbl_blk;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	/* This is the number of clusters used by the superblock,
         * block group descriptors, and reserved block group
         * descriptor blocks */
	num_clusters = ext4_num_base_meta_clusters(sb, block_group);

	/*
         * For the allocation bitmaps and inode table, we first need
         * to check to see if the block is in the block group.  If it
         * is, then check to see if the cluster is already accounted
         * for in the clusters used for the base metadata cluster, or
         * if we can increment the base metadata cluster to include
         * that block.  Otherwise, we will have to track the cluster
         * used for the allocation bitmap or inode table explicitly.
         * Normally all of these blocks are contiguous, so the special
         * case handling shouldn't be necessary except for *very*
         * unusual file system layouts.
         */
	if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) {
		block_cluster = EXT4_B2C(sbi,
					 ext4_block_bitmap(sb, gdp) - start);
		if (block_cluster < num_clusters)
			block_cluster = -1;
		else if (block_cluster == num_clusters) {
			num_clusters++;
			block_cluster = -1;
		}
	}

	if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) {
		inode_cluster = EXT4_B2C(sbi,
					 ext4_inode_bitmap(sb, gdp) - start);
		if (inode_cluster < num_clusters)
			inode_cluster = -1;
		else if (inode_cluster == num_clusters) {
			num_clusters++;
			inode_cluster = -1;
		}
	}

	itbl_blk = ext4_inode_table(sb, gdp);
	for (i = 0; i < sbi->s_itb_per_group; i++) {
		if (ext4_block_in_group(sb, itbl_blk + i, block_group)) {
			c = EXT4_B2C(sbi, itbl_blk + i - start);
			if ((c < num_clusters) || (c == inode_cluster) ||
			    (c == block_cluster) || (c == itbl_cluster))
				continue;
			if (c == num_clusters) {
				num_clusters++;
				continue;
			}
			num_clusters++;
			itbl_cluster = c;
		}
	}

	if (block_cluster != -1)
		num_clusters++;
	if (inode_cluster != -1)
		num_clusters++;

	return num_clusters;
}

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stephen hemminger
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1
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5
100.00%



static unsigned int num_clusters_in_group(struct super_block *sb,
					  ext4_group_t block_group)
{
	unsigned int blocks;

	if (block_group == ext4_get_groups_count(sb) - 1) {
		/*
                 * Even though mke2fs always initializes the first and
                 * last group, just in case some other tool was used,
                 * we need to make sure we calculate the right free
                 * blocks.
                 */
		blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) -
			ext4_group_first_block_no(sb, block_group);
	} else
		blocks = EXT4_BLOCKS_PER_GROUP(sb);
	return EXT4_NUM_B2C(EXT4_SB(sb), blocks);
}

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/* Initializes an uninitialized block bitmap */


static int ext4_init_block_bitmap(struct super_block *sb,
				   struct buffer_head *bh,
				   ext4_group_t block_group,
				   struct ext4_group_desc *gdp)
{
	unsigned int bit, bit_max;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	ext4_fsblk_t start, tmp;
	int flex_bg = 0;
	struct ext4_group_info *grp;

	J_ASSERT_BH(bh, buffer_locked(bh));

	/* If checksum is bad mark all blocks used to prevent allocation
         * essentially implementing a per-group read-only flag. */
	if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
		grp = ext4_get_group_info(sb, block_group);
		if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
			percpu_counter_sub(&sbi->s_freeclusters_counter,
					   grp->bb_free);
		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
			int count;
			count = ext4_free_inodes_count(sb, gdp);
			percpu_counter_sub(&sbi->s_freeinodes_counter,
					   count);
		}
		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
		return -EFSBADCRC;
	}
	memset(bh->b_data, 0, sb->s_blocksize);

	bit_max = ext4_num_base_meta_clusters(sb, block_group);
	if ((bit_max >> 3) >= bh->b_size)
		return -EFSCORRUPTED;

	for (bit = 0; bit < bit_max; bit++)
		ext4_set_bit(bit, bh->b_data);

	start = ext4_group_first_block_no(sb, block_group);

	if (ext4_has_feature_flex_bg(sb))
		flex_bg = 1;

	/* Set bits for block and inode bitmaps, and inode table */
	tmp = ext4_block_bitmap(sb, gdp);
	if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

	tmp = ext4_inode_bitmap(sb, gdp);
	if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

	tmp = ext4_inode_table(sb, gdp);
	for (; tmp < ext4_inode_table(sb, gdp) +
		     sbi->s_itb_per_group; tmp++) {
		if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
			ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
	}

	/*
         * Also if the number of blocks within the group is less than
         * the blocksize * 8 ( which is the size of bitmap ), set rest
         * of the block bitmap to 1
         */
	ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
			     sb->s_blocksize * 8, bh->b_data);
	ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
	ext4_group_desc_csum_set(sb, block_group, gdp);
	return 0;
}

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jose r. santos
82
19.16%
1
5.26%
theodore tso
theodore tso
60
14.02%
5
26.32%
namjae jeon
namjae jeon
52
12.15%
1
5.26%
darrick j. wong
darrick j. wong
47
10.98%
5
26.32%
dmitriy monakhov
dmitriy monakhov
7
1.64%
1
5.26%
aneesh kumar
aneesh kumar
7
1.64%
2
10.53%
akinobu mita
akinobu mita
3
0.70%
1
5.26%
avantika mathur
avantika mathur
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0.23%
1
5.26%
stephen hemminger
stephen hemminger
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1
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/* Return the number of free blocks in a block group.  It is used when
 * the block bitmap is uninitialized, so we can't just count the bits
 * in the bitmap. */


unsigned ext4_free_clusters_after_init(struct super_block *sb,
				       ext4_group_t block_group,
				       struct ext4_group_desc *gdp)
{
	return num_clusters_in_group(sb, block_group) - 
		ext4_num_overhead_clusters(sb, block_group, gdp);
}

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jose r. santos
5
14.29%
1
16.67%
andreas dilger
andreas dilger
4
11.43%
1
16.67%
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35
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6
100.00%

/*
 * The free blocks are managed by bitmaps.  A file system contains several
 * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
 * block for inodes, N blocks for the inode table and data blocks.
 *
 * The file system contains group descriptors which are located after the
 * super block.  Each descriptor contains the number of the bitmap block and
 * the free blocks count in the block.  The descriptors are loaded in memory
 * when a file system is mounted (see ext4_fill_super).
 */

/**
 * ext4_get_group_desc() -- load group descriptor from disk
 * @sb:                 super block
 * @block_group:        given block group
 * @bh:                 pointer to the buffer head to store the block
 *                      group descriptor
 */


struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
					     ext4_group_t block_group,
					     struct buffer_head **bh)
{
	unsigned int group_desc;
	unsigned int offset;
	ext4_group_t ngroups = ext4_get_groups_count(sb);
	struct ext4_group_desc *desc;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (block_group >= ngroups) {
		ext4_error(sb, "block_group >= groups_count - block_group = %u,"
			   " groups_count = %u", block_group, ngroups);

		return NULL;
	}

	group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb);
	offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1);
	if (!sbi->s_group_desc[group_desc]) {
		ext4_error(sb, "Group descriptor not loaded - "
			   "block_group = %u, group_desc = %u, desc = %u",
			   block_group, group_desc, offset);
		return NULL;
	}

	desc = (struct ext4_group_desc *)(
		(__u8 *)sbi->s_group_desc[group_desc]->b_data +
		offset * EXT4_DESC_SIZE(sb));
	if (bh)
		*bh = sbi->s_group_desc[group_desc];
	return desc;
}

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1
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theodore tso
theodore tso
13
7.56%
2
28.57%
mingming cao
mingming cao
10
5.81%
1
14.29%
eric sandeen
eric sandeen
2
1.16%
1
14.29%
avantika mathur
avantika mathur
1
0.58%
1
14.29%
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172
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7
100.00%

/*
 * Return the block number which was discovered to be invalid, or 0 if
 * the block bitmap is valid.
 */


static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
					    struct ext4_group_desc *desc,
					    ext4_group_t block_group,
					    struct buffer_head *bh)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	ext4_grpblk_t offset;
	ext4_grpblk_t next_zero_bit;
	ext4_fsblk_t blk;
	ext4_fsblk_t group_first_block;

	if (ext4_has_feature_flex_bg(sb)) {
		/* with FLEX_BG, the inode/block bitmaps and itable
                 * blocks may not be in the group at all
                 * so the bitmap validation will be skipped for those groups
                 * or it has to also read the block group where the bitmaps
                 * are located to verify they are set.
                 */
		return 0;
	}
	group_first_block = ext4_group_first_block_no(sb, block_group);

	/* check whether block bitmap block number is set */
	blk = ext4_block_bitmap(sb, desc);
	offset = blk - group_first_block;
	if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
		/* bad block bitmap */
		return blk;

	/* check whether the inode bitmap block number is set */
	blk = ext4_inode_bitmap(sb, desc);
	offset = blk - group_first_block;
	if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
		/* bad block bitmap */
		return blk;

	/* check whether the inode table block number is set */
	blk = ext4_inode_table(sb, desc);
	offset = blk - group_first_block;
	next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
			EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group),
			EXT4_B2C(sbi, offset));
	if (next_zero_bit <
	    EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group))
		/* bad bitmap for inode tables */
		return blk;
	return 0;
}

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theodore tso
18
8.45%
1
20.00%
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5
100.00%



static int ext4_validate_block_bitmap(struct super_block *sb,
				      struct ext4_group_desc *desc,
				      ext4_group_t block_group,
				      struct buffer_head *bh)
{
	ext4_fsblk_t	blk;
	struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (buffer_verified(bh))
		return 0;
	if (EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
		return -EFSCORRUPTED;

	ext4_lock_group(sb, block_group);
	if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
			desc, bh))) {
		ext4_unlock_group(sb, block_group);
		ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
		if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
			percpu_counter_sub(&sbi->s_freeclusters_counter,
					   grp->bb_free);
		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
		return -EFSBADCRC;
	}
	blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
	if (unlikely(blk != 0)) {
		ext4_unlock_group(sb, block_group);
		ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
			   block_group, blk);
		if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
			percpu_counter_sub(&sbi->s_freeclusters_counter,
					   grp->bb_free);
		set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
		return -EFSCORRUPTED;
	}
	set_buffer_verified(bh);
	ext4_unlock_group(sb, block_group);
	return 0;
}

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21.10%
1
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theodore tso
40
16.88%
1
12.50%
lukas czerner
lukas czerner
4
1.69%
1
12.50%
stephen hemminger
stephen hemminger
1
0.42%
1
12.50%
Total
237
100.00%
8
100.00%

/**
 * ext4_read_block_bitmap_nowait()
 * @sb:                 super block
 * @block_group:        given block group
 *
 * Read the bitmap for a given block_group,and validate the
 * bits for block/inode/inode tables are set in the bitmaps
 *
 * Return buffer_head on success or NULL in case of failure.
 */

struct buffer_head *

ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
{
	struct ext4_group_desc *desc;
	struct buffer_head *bh;
	ext4_fsblk_t bitmap_blk;
	int err;

	desc = ext4_get_group_desc(sb, block_group, NULL);
	if (!desc)
		return ERR_PTR(-EFSCORRUPTED);
	bitmap_blk = ext4_block_bitmap(sb, desc);
	bh = sb_getblk(sb, bitmap_blk);
	if (unlikely(!bh)) {
		ext4_error(sb, "Cannot get buffer for block bitmap - "
			   "block_group = %u, block_bitmap = %llu",
			   block_group, bitmap_blk);
		return ERR_PTR(-ENOMEM);
	}

	if (bitmap_uptodate(bh))
		goto verify;

	lock_buffer(bh);
	if (bitmap_uptodate(bh)) {
		unlock_buffer(bh);
		goto verify;
	}
	ext4_lock_group(sb, block_group);
	if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
		err = ext4_init_block_bitmap(sb, bh, block_group, desc);
		set_bitmap_uptodate(bh);
		set_buffer_uptodate(bh);
		ext4_unlock_group(sb, block_group);
		unlock_buffer(bh);
		if (err) {
			ext4_error(sb, "Failed to init block bitmap for group "
				   "%u: %d", block_group, err);
			goto out;
		}
		goto verify;
	}
	ext4_unlock_group(sb, block_group);
	if (buffer_uptodate(bh)) {
		/*
                 * if not uninit if bh is uptodate,
                 * bitmap is also uptodate
                 */
		set_bitmap_uptodate(bh);
		unlock_buffer(bh);
		goto verify;
	}
	/*
         * submit the buffer_head for reading
         */
	set_buffer_new(bh);
	trace_ext4_read_block_bitmap_load(sb, block_group);
	bh->b_end_io = ext4_end_bitmap_read;
	get_bh(bh);
	submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
	return bh;
verify:
	err = ext4_validate_block_bitmap(sb, desc, block_group, bh);
	if (err)
		goto out;
	return bh;
out:
	put_bh(bh);
	return ERR_PTR(err);
}

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dave kleikamp
40
12.58%
1
4.17%
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theodore tso
29
9.12%
3
12.50%
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eric sandeen
18
5.66%
1
4.17%
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jan kara
14
4.40%
1
4.17%
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jiaying zhang
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2.20%
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4.17%
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dmitriy monakhov
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1.89%
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5
1.57%
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4.17%
lukas czerner
lukas czerner
3
0.94%
1
4.17%
michael christie
michael christie
2
0.63%
1
4.17%
alexandre ratchov
alexandre ratchov
2
0.63%
1
4.17%
mingming cao
mingming cao
2
0.63%
1
4.17%
avantika mathur
avantika mathur
1
0.31%
1
4.17%
laurent vivier
laurent vivier
1
0.31%
1
4.17%
Total
318
100.00%
24
100.00%

/* Returns 0 on success, 1 on error */


int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group,
			   struct buffer_head *bh)
{
	struct ext4_group_desc *desc;

	if (!buffer_new(bh))
		return 0;
	desc = ext4_get_group_desc(sb, block_group, NULL);
	if (!desc)
		return -EFSCORRUPTED;
	wait_on_buffer(bh);
	if (!buffer_uptodate(bh)) {
		ext4_error(sb, "Cannot read block bitmap - "
			   "block_group = %u, block_bitmap = %llu",
			   block_group, (unsigned long long) bh->b_blocknr);
		return -EIO;
	}
	clear_buffer_new(bh);
	/* Panic or remount fs read-only if block bitmap is invalid */
	return ext4_validate_block_bitmap(sb, desc, block_group, bh);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
66
60.00%
2
20.00%
aneesh kumar
aneesh kumar
24
21.82%
3
30.00%
dave kleikamp
dave kleikamp
8
7.27%
1
10.00%
darrick j. wong
darrick j. wong
6
5.45%
2
20.00%
heiko carstens
heiko carstens
5
4.55%
1
10.00%
andreas dilger
andreas dilger
1
0.91%
1
10.00%
Total
110
100.00%
10
100.00%


struct buffer_head *

ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
{
	struct buffer_head *bh;
	int err;

	bh = ext4_read_block_bitmap_nowait(sb, block_group);
	if (IS_ERR(bh))
		return bh;
	err = ext4_wait_block_bitmap(sb, block_group, bh);
	if (err) {
		put_bh(bh);
		return ERR_PTR(err);
	}
	return bh;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
48
65.75%
1
20.00%
darrick j. wong
darrick j. wong
17
23.29%
1
20.00%
eryu guan
eryu guan
4
5.48%
1
20.00%
dave kleikamp
dave kleikamp
3
4.11%
1
20.00%
aneesh kumar
aneesh kumar
1
1.37%
1
20.00%
Total
73
100.00%
5
100.00%

/**
 * ext4_has_free_clusters()
 * @sbi:        in-core super block structure.
 * @nclusters:  number of needed blocks
 * @flags:      flags from ext4_mb_new_blocks()
 *
 * Check if filesystem has nclusters free & available for allocation.
 * On success return 1, return 0 on failure.
 */


static int ext4_has_free_clusters(struct ext4_sb_info *sbi,
				  s64 nclusters, unsigned int flags)
{
	s64 free_clusters, dirty_clusters, rsv, resv_clusters;
	struct percpu_counter *fcc = &sbi->s_freeclusters_counter;
	struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter;

	free_clusters  = percpu_counter_read_positive(fcc);
	dirty_clusters = percpu_counter_read_positive(dcc);
	resv_clusters = atomic64_read(&sbi->s_resv_clusters);

	/*
         * r_blocks_count should always be multiple of the cluster ratio so
         * we are safe to do a plane bit shift only.
         */
	rsv = (ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits) +
	      resv_clusters;

	if (free_clusters - (nclusters + rsv + dirty_clusters) <
					EXT4_FREECLUSTERS_WATERMARK) {
		free_clusters  = percpu_counter_sum_positive(fcc);
		dirty_clusters = percpu_counter_sum_positive(dcc);
	}
	/* Check whether we have space after accounting for current
         * dirty clusters & root reserved clusters.
         */
	if (free_clusters >= (rsv + nclusters + dirty_clusters))
		return 1;

	/* Hm, nope.  Are (enough) root reserved clusters available? */
	if (uid_eq(sbi->s_resuid, current_fsuid()) ||
	    (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) ||
	    capable(CAP_SYS_RESOURCE) ||
	    (flags & EXT4_MB_USE_ROOT_BLOCKS)) {

		if (free_clusters >= (nclusters + dirty_clusters +
				      resv_clusters))
			return 1;
	}
	/* No free blocks. Let's see if we can dip into reserved pool */
	if (flags & EXT4_MB_USE_RESERVED) {
		if (free_clusters >= (nclusters + dirty_clusters))
			return 1;
	}

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
91
41.36%
4
26.67%
lukas czerner
lukas czerner
49
22.27%
2
13.33%
eric sandeen
eric sandeen
40
18.18%
2
13.33%
eric w. biederman
eric w. biederman
10
4.55%
1
6.67%
allison henderson
allison henderson
10
4.55%
1
6.67%
aneesh kumar
aneesh kumar
8
3.64%
1
6.67%
jose r. santos
jose r. santos
6
2.73%
1
6.67%
david howells
david howells
2
0.91%
1
6.67%
dave kleikamp
dave kleikamp
2
0.91%
1
6.67%
andrew morton
andrew morton
2
0.91%
1
6.67%
Total
220
100.00%
15
100.00%



int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
			     s64 nclusters, unsigned int flags)
{
	if (ext4_has_free_clusters(sbi, nclusters, flags)) {
		percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
		return 0;
	} else
		return -ENOSPC;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
25
52.08%
4
57.14%
eric sandeen
eric sandeen
9
18.75%
1
14.29%
dave kleikamp
dave kleikamp
8
16.67%
1
14.29%
allison henderson
allison henderson
6
12.50%
1
14.29%
Total
48
100.00%
7
100.00%

/**
 * ext4_should_retry_alloc()
 * @sb:                 super block
 * @retries             number of attemps has been made
 *
 * ext4_should_retry_alloc() is called when ENOSPC is returned, and if
 * it is profitable to retry the operation, this function will wait
 * for the current or committing transaction to complete, and then
 * return TRUE.
 *
 * if the total number of retries exceed three times, return FALSE.
 */


int ext4_should_retry_alloc(struct super_block *sb, int *retries)
{
	if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
	    (*retries)++ > 3 ||
	    !EXT4_SB(sb)->s_journal)
		return 0;

	jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);

	smp_mb();
	if (EXT4_SB(sb)->s_mb_free_pending)
		jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
	return 1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
57
67.86%
3
42.86%
dave kleikamp
dave kleikamp
14
16.67%
1
14.29%
eric sandeen
eric sandeen
8
9.52%
1
14.29%
jan kara
jan kara
3
3.57%
1
14.29%
allison henderson
allison henderson
2
2.38%
1
14.29%
Total
84
100.00%
7
100.00%

/*
 * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
 *
 * @handle:             handle to this transaction
 * @inode:              file inode
 * @goal:               given target block(filesystem wide)
 * @count:              pointer to total number of clusters needed
 * @errp:               error code
 *
 * Return 1st allocated block number on success, *count stores total account
 * error stores in errp pointer
 */


ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
				  ext4_fsblk_t goal, unsigned int flags,
				  unsigned long *count, int *errp)
{
	struct ext4_allocation_request ar;
	ext4_fsblk_t ret;

	memset(&ar, 0, sizeof(ar));
	/* Fill with neighbour allocated blocks */
	ar.inode = inode;
	ar.goal = goal;
	ar.len = count ? *count : 1;
	ar.flags = flags;

	ret = ext4_mb_new_blocks(handle, &ar, errp);
	if (count)
		*count = ar.len;
	/*
         * Account for the allocated meta blocks.  We will never
         * fail EDQUOT for metdata, but we do account for it.
         */
	if (!(*errp) && (flags & EXT4_MB_DELALLOC_RESERVED)) {
		dquot_alloc_block_nofail(inode,
				EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
	}
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
alex tomas
alex tomas
49
34.51%
1
8.33%
aneesh kumar
aneesh kumar
18
12.68%
3
25.00%
dave kleikamp
dave kleikamp
17
11.97%
1
8.33%
mingming cao
mingming cao
14
9.86%
2
16.67%
theodore tso
theodore tso
14
9.86%
2
16.67%
eric sandeen
eric sandeen
10
7.04%
1
8.33%
aditya kali
aditya kali
10
7.04%
1
8.33%
allison henderson
allison henderson
10
7.04%
1
8.33%
Total
142
100.00%
12
100.00%

/**
 * ext4_count_free_clusters() -- count filesystem free clusters
 * @sb:         superblock
 *
 * Adds up the number of free clusters from each block group.
 */


ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb)
{
	ext4_fsblk_t desc_count;
	struct ext4_group_desc *gdp;
	ext4_group_t i;
	ext4_group_t ngroups = ext4_get_groups_count(sb);
	struct ext4_group_info *grp;
#ifdef EXT4FS_DEBUG
	struct ext4_super_block *es;
	ext4_fsblk_t bitmap_count;
	unsigned int x;
	struct buffer_head *bitmap_bh = NULL;

	es = EXT4_SB(sb)->s_es;
	desc_count = 0;
	bitmap_count = 0;
	gdp = NULL;

	for (i = 0; i < ngroups; i++) {
		gdp = ext4_get_group_desc(sb, i, NULL);
		if (!gdp)
			continue;
		grp = NULL;
		if (EXT4_SB(sb)->s_group_info)
			grp = ext4_get_group_info(sb, i);
		if (