* [PATCH] f2fs: avoid to issue redundant discard commands
@ 2017-02-27 21:43 ` Jaegeuk Kim
0 siblings, 0 replies; 2+ messages in thread
From: Jaegeuk Kim @ 2017-02-27 21:43 UTC (permalink / raw)
To: linux-kernel, linux-fsdevel, linux-f2fs-devel
Cc: Jaegeuk Kim, stable, Damien Le Moal
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: <stable@vger.kernel.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/segment.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9006d8ed6f52..4bd7a8b19332 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1036,6 +1036,8 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
start = start_segno + sbi->segs_per_sec;
if (start < end)
goto next;
+ else
+ end = start - 1;
}
mutex_unlock(&dirty_i->seglist_lock);
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] f2fs: avoid to issue redundant discard commands
@ 2017-02-27 21:43 ` Jaegeuk Kim
0 siblings, 0 replies; 2+ messages in thread
From: Jaegeuk Kim @ 2017-02-27 21:43 UTC (permalink / raw)
To: linux-kernel, linux-fsdevel, linux-f2fs-devel
Cc: Jaegeuk Kim, Damien Le Moal, stable
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: <stable@vger.kernel.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/segment.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9006d8ed6f52..4bd7a8b19332 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1036,6 +1036,8 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
start = start_segno + sbi->segs_per_sec;
if (start < end)
goto next;
+ else
+ end = start - 1;
}
mutex_unlock(&dirty_i->seglist_lock);
--
2.11.0
------------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2017-02-27 21:53 UTC | newest]
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2017-02-27 21:43 ` Jaegeuk Kim
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