Commit c89849cc authored by Pan Dong's avatar Pan Dong Committed by Theodore Ts'o
Browse files

ext4: fix avefreec in find_group_orlov 



The avefreec should be average free clusters instead
of average free blocks, otherwize Orlov's allocator
will not work properly when bigalloc enabled.

Cc: stable@kernel.org
Signed-off-by: default avatarPan Dong <pandong.peter@bytedance.com>
Link: https://lore.kernel.org/r/20210525073656.31594-1-pandong.peter@bytedance.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 4fb7c70a

fs/ext4/ialloc.c

+5 −6
Original line number Diff line number Diff line
@@ -402,7 +402,7 @@ static void get_orlov_stats(struct super_block *sb, ext4_group_t g, 
 *

 * We always try to spread first-level directories.

 *

 * If there are blockgroups with both free inodes and free blocks counts

 * If there are blockgroups with both free inodes and free clusters counts

 * not worse than average we return one with smallest directory count.

 * Otherwise we simply return a random group.

 *
@@ -411,7 +411,7 @@ static void get_orlov_stats(struct super_block *sb, ext4_group_t g, 
 * 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

 * it has too few free clusters left (min_clusters) 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
@@ -427,7 +427,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, 
	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;

	ext4_fsblk_t freec, avefreec;

	unsigned int ndirs;

	int max_dirs, min_inodes;

	ext4_grpblk_t min_clusters;
@@ -446,9 +446,8 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent, 


	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;

	freec = percpu_counter_read_positive(&sbi->s_freeclusters_counter);

	avefreec = freec;

	do_div(avefreec, ngroups);

	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);