Release 4.10 fs/ext4/ialloc.c

/*
 *  linux/fs/ext4/ialloc.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)
 *
 *  BSD ufs-inspired inode and directory 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/fs.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/random.h>
#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <asm/byteorder.h>

#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"

#include <trace/events/ext4.h>

/*
 * ialloc.c contains the inodes allocation and deallocation routines
 */

/*
 * The free inodes 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.
 */

/*
 * To avoid calling the atomic setbit hundreds or thousands of times, we only
 * need to use it within a single byte (to ensure we get endianness right).
 * We can use memset for the rest of the bitmap as there are no other users.
 */


void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
{
	int i;

	if (start_bit >= end_bit)
		return;

	ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit);
	for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
		ext4_set_bit(i, bitmap);
	if (i < end_bit)
		memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
andreas dilger
andreas dilger
89
98.89%
1
50.00%
theodore tso
theodore tso
1
1.11%
1
50.00%
Total
90
100.00%
2
100.00%

/* Initializes an uninitialized inode bitmap */


static int ext4_init_inode_bitmap(struct super_block *sb,
				       struct buffer_head *bh,
				       ext4_group_t block_group,
				       struct ext4_group_desc *gdp)
{
	struct ext4_group_info *grp;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	J_ASSERT_BH(bh, buffer_locked(bh));

	/* If checksum is bad mark all blocks and inodes use 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, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
	ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
			bh->b_data);
	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
				   EXT4_INODES_PER_GROUP(sb) / 8);
	ext4_group_desc_csum_set(sb, block_group, gdp);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
andreas dilger
andreas dilger
88
40.55%
1
9.09%
namjae jeon
namjae jeon
62
28.57%
1
9.09%
darrick j. wong
darrick j. wong
56
25.81%
4
36.36%
aneesh kumar
aneesh kumar
8
3.69%
2
18.18%
theodore tso
theodore tso
2
0.92%
2
18.18%
avantika mathur
avantika mathur
1
0.46%
1
9.09%
Total
217
100.00%
11
100.00%



void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
{
	if (uptodate) {
		set_buffer_uptodate(bh);
		set_bitmap_uptodate(bh);
	}
	unlock_buffer(bh);
	put_bh(bh);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
39
100.00%
1
100.00%
Total
39
100.00%
1
100.00%



static int ext4_validate_inode_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_IBITMAP_CORRUPT(grp))
		return -EFSCORRUPTED;

	ext4_lock_group(sb, block_group);
	blk = ext4_inode_bitmap(sb, desc);
	if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
					   EXT4_INODES_PER_GROUP(sb) / 8)) {
		ext4_unlock_group(sb, block_group);
		ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
			   "inode_bitmap = %llu", block_group, blk);
		grp = ext4_get_group_info(sb, block_group);
		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
			int count;
			count = ext4_free_inodes_count(sb, desc);
			percpu_counter_sub(&sbi->s_freeinodes_counter,
					   count);
		}
		set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state);
		return -EFSBADCRC;
	}
	set_buffer_verified(bh);
	ext4_unlock_group(sb, block_group);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
darrick j. wong
darrick j. wong
198
100.00%
1
100.00%
Total
198
100.00%
1
100.00%

/*
 * Read the inode allocation bitmap for a given block_group, reading
 * into the specified slot in the superblock's bitmap cache.
 *
 * Return buffer_head of bitmap on success or NULL.
 */

static struct buffer_head *

ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
{
	struct ext4_group_desc *desc;
	struct buffer_head *bh = NULL;
	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_inode_bitmap(sb, desc);
	bh = sb_getblk(sb, bitmap_blk);
	if (unlikely(!bh)) {
		ext4_error(sb, "Cannot read inode bitmap - "
			    "block_group = %u, inode_bitmap = %llu",
			    block_group, bitmap_blk);
		return ERR_PTR(-EIO);
	}
	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_INODE_UNINIT)) {
		err = ext4_init_inode_bitmap(sb, bh, block_group, desc);
		set_bitmap_uptodate(bh);
		set_buffer_uptodate(bh);
		set_buffer_verified(bh);
		ext4_unlock_group(sb, block_group);
		unlock_buffer(bh);
		if (err) {
			ext4_error(sb, "Failed to init inode bitmap for group "
				   "%u: %d", block_group, err);
			goto out;
		}
		return bh;
	}
	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
         */
	trace_ext4_load_inode_bitmap(sb, block_group);
	bh->b_end_io = ext4_end_bitmap_read;
	get_bh(bh);
	submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
	wait_on_buffer(bh);
	if (!buffer_uptodate(bh)) {
		put_bh(bh);
		ext4_error(sb, "Cannot read inode bitmap - "
			   "block_group = %u, inode_bitmap = %llu",
			   block_group, bitmap_blk);
		return ERR_PTR(-EIO);
	}

verify:
	err = ext4_validate_inode_bitmap(sb, desc, block_group, bh);
	if (err)
		goto out;
	return bh;
out:
	put_bh(bh);
	return ERR_PTR(err);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
darrick j. wong
darrick j. wong
73
20.45%
3
15.00%
eric sandeen
eric sandeen
70
19.61%
2
10.00%
dave kleikamp
dave kleikamp
56
15.69%
1
5.00%
aneesh kumar
aneesh kumar
52
14.57%
3
15.00%
andreas dilger
andreas dilger
44
12.32%
1
5.00%
theodore tso
theodore tso
26
7.28%
3
15.00%
jan kara
jan kara
14
3.92%
1
5.00%
jiaying zhang
jiaying zhang
7
1.96%
1
5.00%
frederic bohe
frederic bohe
5
1.40%
1
5.00%
namjae jeon
namjae jeon
4
1.12%
1
5.00%
mingming cao
mingming cao
3
0.84%
1
5.00%
michael christie
michael christie
2
0.56%
1
5.00%
avantika mathur
avantika mathur
1
0.28%
1
5.00%
Total
357
100.00%
20
100.00%

/*
 * NOTE! When we get the inode, we're the only people
 * that have access to it, and as such there are no
 * race conditions we have to worry about. The inode
 * is not on the hash-lists, and it cannot be reached
 * through the filesystem because the directory entry
 * has been deleted earlier.
 *
 * HOWEVER: we must make sure that we get no aliases,
 * which means that we have to call "clear_inode()"
 * _before_ we mark the inode not in use in the inode
 * bitmaps. Otherwise a newly created file might use
 * the same inode number (not actually the same pointer
 * though), and then we'd have two inodes sharing the
 * same inode number and space on the harddisk.
 */


void ext4_free_inode(handle_t *handle, struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	int is_directory;
	unsigned long ino;
	struct buffer_head *bitmap_bh = NULL;
	struct buffer_head *bh2;
	ext4_group_t block_group;
	unsigned long bit;
	struct ext4_group_desc *gdp;
	struct ext4_super_block *es;
	struct ext4_sb_info *sbi;
	int fatal = 0, err, count, cleared;
	struct ext4_group_info *grp;

	if (!sb) {
		printk(KERN_ERR "EXT4-fs: %s:%d: inode on "
		       "nonexistent device\n", __func__, __LINE__);
		return;
	}
	if (atomic_read(&inode->i_count) > 1) {
		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d",
			 __func__, __LINE__, inode->i_ino,
			 atomic_read(&inode->i_count));
		return;
	}
	if (inode->i_nlink) {
		ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n",
			 __func__, __LINE__, inode->i_ino, inode->i_nlink);
		return;
	}
	sbi = EXT4_SB(sb);

	ino = inode->i_ino;
	ext4_debug("freeing inode %lu\n", ino);
	trace_ext4_free_inode(inode);

	/*
         * Note: we must free any quota before locking the superblock,
         * as writing the quota to disk may need the lock as well.
         */
	dquot_initialize(inode);
	ext4_xattr_delete_inode(handle, inode);
	dquot_free_inode(inode);
	dquot_drop(inode);

	is_directory = S_ISDIR(inode->i_mode);

	/* Do this BEFORE marking the inode not in use or returning an error */
	ext4_clear_inode(inode);

	es = EXT4_SB(sb)->s_es;
	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
		ext4_error(sb, "reserved or nonexistent inode %lu", ino);
		goto error_return;
	}
	block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
	/* Don't bother if the inode bitmap is corrupt. */
	grp = ext4_get_group_info(sb, block_group);
	if (IS_ERR(bitmap_bh)) {
		fatal = PTR_ERR(bitmap_bh);
		bitmap_bh = NULL;
		goto error_return;
	}
	if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) {
		fatal = -EFSCORRUPTED;
		goto error_return;
	}

	BUFFER_TRACE(bitmap_bh, "get_write_access");
	fatal = ext4_journal_get_write_access(handle, bitmap_bh);
	if (fatal)
		goto error_return;

	fatal = -ESRCH;
	gdp = ext4_get_group_desc(sb, block_group, &bh2);
	if (gdp) {
		BUFFER_TRACE(bh2, "get_write_access");
		fatal = ext4_journal_get_write_access(handle, bh2);
	}
	ext4_lock_group(sb, block_group);
	cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
	if (fatal || !cleared) {
		ext4_unlock_group(sb, block_group);
		goto out;
	}

	count = ext4_free_inodes_count(sb, gdp) + 1;
	ext4_free_inodes_set(sb, gdp, count);
	if (is_directory) {
		count = ext4_used_dirs_count(sb, gdp) - 1;
		ext4_used_dirs_set(sb, gdp, count);
		percpu_counter_dec(&sbi->s_dirs_counter);
	}
	ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
				   EXT4_INODES_PER_GROUP(sb) / 8);
	ext4_group_desc_csum_set(sb, block_group, gdp);
	ext4_unlock_group(sb, block_group);

	percpu_counter_inc(&sbi->s_freeinodes_counter);
	if (sbi->s_log_groups_per_flex) {
		ext4_group_t f = ext4_flex_group(sbi, block_group);

		atomic_inc(&sbi->s_flex_groups[f].free_inodes);
		if (is_directory)
			atomic_dec(&sbi->s_flex_groups[f].used_dirs);
	}
	BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
	fatal = ext4_handle_dirty_metadata(handle, NULL, bh2);
out:
	if (cleared) {
		BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
		err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
		if (!fatal)
			fatal = err;
	} else {
		ext4_error(sb, "bit already cleared for inode %lu", ino);
		if (gdp && !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);
	}

error_return:
	brelse(bitmap_bh);
	ext4_std_error(sb, fatal);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
dave kleikamp
dave kleikamp
373
51.31%
1
3.45%
darrick j. wong
darrick j. wong
82
11.28%
4
13.79%
dmitriy monakhov
dmitriy monakhov
71
9.77%
1
3.45%
theodore tso
theodore tso
64
8.80%
6
20.69%
aneesh kumar
aneesh kumar
36
4.95%
2
6.90%
namjae jeon
namjae jeon
34
4.68%
2
6.90%
jose r. santos
jose r. santos
21
2.89%
1
3.45%
mingming cao
mingming cao
16
2.20%
1
3.45%
andreas dilger
andreas dilger
11
1.51%
1
3.45%
frank mayhar
frank mayhar
8
1.10%
1
3.45%
eric sandeen
eric sandeen
3
0.41%
2
6.90%
christoph hellwig
christoph hellwig
3
0.41%
3
10.34%
marcin slusarz
marcin slusarz
2
0.28%
1
3.45%
al viro
al viro
1
0.14%
1
3.45%
avantika mathur
avantika mathur
1
0.14%
1
3.45%
akinobu mita
akinobu mita
1
0.14%
1
3.45%
Total
727
100.00%
29
100.00%


struct orlov_stats {
	
__u64 free_clusters;
	
__u32 free_inodes;
	
__u32 used_dirs;
};

/*
 * Helper function for Orlov's allocator; returns critical information
 * for a particular block group or flex_bg.  If flex_size is 1, then g
 * is a block group number; otherwise it is flex_bg number.
 */


static void get_orlov_stats(struct super_block *sb, ext4_group_t g,
			    int flex_size, struct orlov_stats *stats)
{
	struct ext4_group_desc *desc;
	struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups;

	if (flex_size > 1) {
		stats->free_inodes = atomic_read(&flex_group[g].free_inodes);
		stats->free_clusters = atomic64_read(&flex_group[g].free_clusters);
		stats->used_dirs = atomic_read(&flex_group[g].used_dirs);
		return;
	}

	desc = ext4_get_group_desc(sb, g, NULL);
	if (desc) {
		stats->free_inodes = ext4_free_inodes_count(sb, desc);
		stats->free_clusters = ext4_free_group_clusters(sb, desc);
		stats->used_dirs = ext4_used_dirs_count(sb, desc);
	} else {
		stats->free_inodes = 0;
		stats->free_clusters = 0;
		stats->used_dirs = 0;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
164
100.00%
6
100.00%
Total
164
100.00%
6
100.00%

/*
 * Orlov's allocator for directories.
 *
 * We always try to spread first-level directories.
 *
 * If there are blockgroups with both free inodes and free blocks counts
 * not worse than average we return one with smallest directory count.
 * Otherwise we simply return a random group.
 *
 * For the rest rules look so:
 *
 * It's OK to put directory into a group unless
 * it has too many directories already (max_dirs) or
 * it has too few free inodes left (min_inodes) or
 * it has too few free blocks left (min_blocks) or
 * Parent's group is preferred, if it doesn't satisfy these
 * conditions we search cyclically through the rest. If none
 * of the groups look good we just look for a group with more
 * free inodes than average (starting at parent's group).
 */



static int find_group_orlov(struct super_block *sb, struct inode *parent,
			    ext4_group_t *group, umode_t mode,
			    const struct qstr *qstr)
{
	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	ext4_group_t real_ngroups = ext4_get_groups_count(sb);
	int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
	unsigned int freei, avefreei, grp_free;
	ext4_fsblk_t freeb, avefreec;
	unsigned int ndirs;
	int max_dirs, min_inodes;
	ext4_grpblk_t min_clusters;
	ext4_group_t i, grp, g, ngroups;
	struct ext4_group_desc *desc;
	struct orlov_stats stats;
	int flex_size = ext4_flex_bg_size(sbi);
	struct dx_hash_info hinfo;

	ngroups = real_ngroups;
	if (flex_size > 1) {
		ngroups = (real_ngroups + flex_size - 1) >>
			sbi->s_log_groups_per_flex;
		parent_group >>= sbi->s_log_groups_per_flex;
	}

	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
	avefreei = freei / ngroups;
	freeb = EXT4_C2B(sbi,
		percpu_counter_read_positive(&sbi->s_freeclusters_counter));
	avefreec = freeb;
	do_div(avefreec, ngroups);
	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);

	if (S_ISDIR(mode) &&
	    ((parent == d_inode(sb->s_root)) ||
	     (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) {
		int best_ndir = inodes_per_group;
		int ret = -1;

		if (qstr) {
			hinfo.hash_version = DX_HASH_HALF_MD4;
			hinfo.seed = sbi->s_hash_seed;
			ext4fs_dirhash(qstr->name, qstr->len, &hinfo);
			grp = hinfo.hash;
		} else
			grp = prandom_u32();
		parent_group = (unsigned)grp % ngroups;
		for (i = 0; i < ngroups; i++) {
			g = (parent_group + i) % ngroups;
			get_orlov_stats(sb, g, flex_size, &stats);
			if (!stats.free_inodes)
				continue;
			if (stats.used_dirs >= best_ndir)
				continue;
			if (stats.free_inodes < avefreei)
				continue;
			if (stats.free_clusters < avefreec)
				continue;
			grp = g;
			ret = 0;
			best_ndir = stats.used_dirs;
		}
		if (ret)
			goto fallback;
	found_flex_bg:
		if (flex_size == 1) {
			*group = grp;
			return 0;
		}

		/*
                 * We pack inodes at the beginning of the flexgroup's
                 * inode tables.  Block allocation decisions will do
                 * something similar, although regular files will
                 * start at 2nd block group of the flexgroup.  See
                 * ext4_ext_find_goal() and ext4_find_near().
                 */
		grp *= flex_size;
		for (i = 0; i < flex_size; i++) {
			if (grp+i >= real_ngroups)
				break;
			desc = ext4_get_group_desc(sb, grp+i, NULL);
			if (desc && ext4_free_inodes_count(sb, desc)) {
				*group = grp+i;
				return 0;
			}
		}
		goto fallback;
	}

	max_dirs = ndirs / ngroups + inodes_per_group / 16;
	min_inodes = avefreei - inodes_per_group*flex_size / 4;
	if (min_inodes < 1)
		min_inodes = 1;
	min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4;

	/*
         * Start looking in the flex group where we last allocated an
         * inode for this parent directory
         */
	if (EXT4_I(parent)->i_last_alloc_group != ~0) {
		parent_group = EXT4_I(parent)->i_last_alloc_group;
		if (flex_size > 1)
			parent_group >>= sbi->s_log_groups_per_flex;
	}

	for (i = 0; i < ngroups; i++) {
		grp = (parent_group + i) % ngroups;
		get_orlov_stats(sb, grp, flex_size, &stats);
		if (stats.used_dirs >= max_dirs)
			continue;
		if (stats.free_inodes < min_inodes)
			continue;
		if (stats.free_clusters < min_clusters)
			continue;
		goto found_flex_bg;
	}

fallback:
	ngroups = real_ngroups;
	avefreei = freei / ngroups;
fallback_retry:
	parent_group = EXT4_I(parent)->i_block_group;
	for (i = 0; i < ngroups; i++) {
		grp = (parent_group + i) % ngroups;
		desc = ext4_get_group_desc(sb, grp, NULL);
		if (desc) {
			grp_free = ext4_free_inodes_count(sb, desc);
			if (grp_free && grp_free >= avefreei) {
				*group = grp;
				return 0;
			}
		}
	}

	if (avefreei) {
		/*
                 * The free-inodes counter is approximate, and for really small
                 * filesystems the above test can fail to find any blockgroups
                 */
		avefreei = 0;
		goto fallback_retry;
	}

	return -1;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
theodore tso
theodore tso
341
46.33%
8
40.00%
dave kleikamp
dave kleikamp
336
45.65%
1
5.00%
avantika mathur
avantika mathur
19
2.58%
2
10.00%
mingming cao
mingming cao
16
2.17%
2
10.00%
aneesh kumar
aneesh kumar
9
1.22%
1
5.00%
dan carpenter
dan carpenter
6
0.82%
1
5.00%
david howells
david howells
3
0.41%
1
5.00%
dmitriy monakhov
dmitriy monakhov
3
0.41%
1
5.00%
eric sandeen
eric sandeen
1
0.14%
1
5.00%
andrew morton
andrew morton
1
0.14%
1
5.00%
al viro
al viro
1
0.14%
1
5.00%
Total
736
100.00%
20
100.00%



static int find_group_other(struct super_block *sb, struct inode *parent,
			    ext4_group_t *group, umode_t mode)
{
	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
	ext4_group_t i, last, ngroups = ext4_get_groups_count(sb);
	struct ext4_group_desc *desc;
	int flex_size = ext4_flex_bg_size(EXT4_SB(sb));

	/*
         * Try to place the inode is the same flex group as its
         * parent.  If we can't find space, use the Orlov algorithm to
         * find another flex group, and store that information in the
         * parent directory's inode information so that use that flex
         * group for future allocations.
         */
	if (flex_size > 1) {
		int retry = 0;

	try_again:
		parent_group &= ~(flex_size-1);
		last = parent_group + flex_size;
		if (last > ngroups)
			last = ngroups;
		for  (i = parent_group; i < last; i++) {
			desc = ext4_get_group_desc(sb, i, NULL);
			if (desc && ext4_free_inodes_count(sb, desc)) {
				*group = i;
				return 0;
			}
		}
		if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) {
			retry = 1;
			parent_group = EXT4_I(parent)->i_last_alloc_group;
			goto try_again;
		}
		/*
                 * If this didn't work, use the Orlov search algorithm
                 * to find a new flex group; we pass in the mode to
                 * avoid the topdir algorithms.
                 */
		*group = parent_group + flex_size;
		if (*group > ngroups)
			*group = 0;
		return find_group_orlov(sb, parent, group, mode, NULL);
	}

	/*
         * Try to place the inode in its parent directory
         */
	*group = parent_group;
	desc = ext4_get_group_desc(sb, *group, NULL);
	if (desc && ext4_free_inodes_count(sb, desc) &&
	    ext4_free_group_clusters(sb, desc))
		return 0;

	/*
         * We're going to place this inode in a different blockgroup from its
         * parent.  We want to cause files in a common directory to all land in
         * the same blockgroup.  But we want files which are in a different
         * directory which shares a blockgroup with our parent to land in a
         * different blockgroup.
         *
         * So add our directory's i_ino into the starting point for the hash.
         */
	*group = (*group + parent->i_ino) %