ext4: make directory inode spreading reflect flexbg size

commit 613c5a85898d1cd44e68f28d65eccf64a8ace9cf upstream.

Currently the Orlov inode allocator searches for free inodes for a
directory only in flex block groups with at most inodes_per_group/16
more directory inodes than average per flex block group. However with
growing size of flex block group this becomes unnecessarily strict.
Scale allowed difference from average directory count per flex block
group with flex block group size as we do with other metrics.

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220908092136.11770-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index f73e5eb43eae1dace29cd0082500be7ebbe71e06..208b87ce885889fa6c0ec83c59e061ed36a87b41 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -510,7 +510,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent,
                goto fallback;
        }
 
-       max_dirs = ndirs / ngroups + inodes_per_group / 16;
+       max_dirs = ndirs / ngroups + inodes_per_group*flex_size / 16;
        min_inodes = avefreei - inodes_per_group*flex_size / 4;
        if (min_inodes < 1)
                min_inodes = 1;