| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 133/153] f2fs: avoid to issue redundant discard commands | Date | Fri, 10 Mar 2017 10:09:26 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jaegeuk Kim <jaegeuk@kernel.org>
commit 8b107f5b97772c7c0c218302e9a4d15b4edf50b4 upstream.
If segs_per_sec is over 1 like under SMR, previously f2fs issues discard commands redundantly on the same section, since we didn't move end position for the previous discard command.
E.g.,
start end | | prefree_bitmap = [01111100111100]
And, after issue discard for this section, end start | | prefree_bitmap = [01111100111100]
Select this section again by searching from (end + 1), start end | | prefree_bitmap = [01111100111100]
Fixes: 36abef4e796d38 ("f2fs: introduce mode=lfs mount option") Cc: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/f2fs/segment.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -813,6 +813,8 @@ next: start = start_segno + sbi->segs_per_sec; if (start < end) goto next; + else + end = start - 1; } mutex_unlock(&dirty_i->seglist_lock);
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