From patchwork Thu Aug 16 18:53:37 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Far too long mount time Date: Thu, 16 Aug 2012 08:53:37 -0000 From: Theodore Ts'o X-Patchwork-Id: 178075 Message-Id: <20120816185337.GB31346@thunk.org> To: Calvin Walton Cc: Andreas Dilger , Javier Marcet , Linux Ext4 Mailing List , jpiszcz@lucidpixels.com On Thu, Aug 16, 2012 at 10:42:19AM -0400, Theodore Ts'o wrote: > On Thu, Aug 16, 2012 at 10:16:48AM -0400, Calvin Walton wrote: > > On Thu, 2012-08-16 at 03:09 -0600, Andreas Dilger wrote: > > Is there any fix for this issue queued up for an upcoming stable > > release? It still reverts cleanly on 3.5.2. > > There isn't a fix queued up yet, but there will be one soon.... This patch should solve the problem (as an alternative to reverting 8aeb00ff85a). - Ted >From dc43c7a8a6c266c31aa4f0408000c4d1b9f3c787 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 16 Aug 2012 11:59:04 -0400 Subject: [PATCH] ext4: fix long mount times on very big file systems 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" Cc: stable@vger.kernel.org --- fs/ext4/super.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 603023b..055c65b 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3129,6 +3129,10 @@ static int count_overhead(struct super_block *sb, ext4_group_t grp, 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, i) + + 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;