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author | Jan Kara <jack@suse.cz> | 2008-02-06 01:37:36 -0800 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-06 10:41:07 -0800 |
commit | 941d2380e979dfefb6c824452e9f42be3ef948ee (patch) | |
tree | 4aad1ad817fb2043b8191ef77ec96845b9c24313 /fs/timerfd.c | |
parent | bed9759b2e6bd938097389f6bd2ac8d622fa3884 (diff) | |
download | op-kernel-dev-941d2380e979dfefb6c824452e9f42be3ef948ee.zip op-kernel-dev-941d2380e979dfefb6c824452e9f42be3ef948ee.tar.gz |
quota: improve inode list scanning in add_dquot_ref()
We restarted scan of sb->s_inodes list whenever we had to drop inode_lock
in add_dquot_ref(). This leads to overall quadratic running time and thus
add_dquot_ref() can take several minutes when called on a life filesystem.
We fix the problem by using the fact that inode cannot be removed from
s_inodes list while we hold a reference to it and thus we can safely
restart the scan if we don't drop the reference. Here we use the fact that
inodes freshly added to s_inodes list are already guaranteed to have quotas
properly initialized and the ordering of inodes on s_inodes list does not
change so we cannot skip any inode.
Thanks goes to Nick <gentuu@gmail.com> for analyzing the problem and
testing the fix.
[akpm@linux-foundation.org: iput(NULL) is legal]
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Nick <gentuu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/timerfd.c')
0 files changed, 0 insertions, 0 deletions