From: Greg KH <gre...@linuxfoundation.org>

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <ty...@mit.edu>

commit 0548bbb85337e532ca2ed697c3e9b227ff2ed4b4 upstream.

Commit 8aeb00ff85a: "ext4: fix overhead calculation used by
ext4_statfs()" introduced a O(n**2) calculation which makes very large
file systems take forever to mount.  Fix this with an optimization for
non-bigalloc file systems.  (For bigalloc file systems the overhead
needs to be set in the the superblock.)

Signed-off-by: "Theodore Ts'o" <ty...@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/ext4/super.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2969,6 +2969,10 @@ static int count_overhead(struct super_b
        ext4_group_t            i, ngroups = ext4_get_groups_count(sb);
        int                     s, j, count = 0;
 
+       if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
+               return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
+                       sbi->s_itb_per_group + 2);
+
        first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
                (grp * EXT4_BLOCKS_PER_GROUP(sb));
        last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to