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 4966c6d24ad2c934ff5d7138a1e5f751b4ec6ce1..17d7b86a6419d84bb6c333d679aa8cd7f65149c2 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -511,7 +511,7 @@ 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;