3.16.54-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Dongho Sim <dh.sim@xxxxxxxxxxx>
commit 33be828ada7274ebcade2001f16e5b4e33a4636e upstream.
There are redundant lines in allocate_data_block.
In this function, we call refresh_sit_entry with old seg and old curseg.
After that, we call locate_dirty_segment with old curseg.
But, the new address is always allocated from old curseg and
we call locate_dirty_segment with old curseg in refresh_sit_entry.
So, we do not need to call locate_dirty_segment with old curseg again.
We've discussed like below:
Jaegeuk said:
"When considering SSR, we need to take care of the following scenario.
- old segno : X
- new address : Z
- old curseg : Y
This means, a new block is supposed to be written to Z from X.
And Z is newly allocated in the same path from Y.
In that case, we should trigger locate_dirty_segment for Y, since
it was a current_segment and can be dirty owing to SSR.
But that was not included in the dirty list."
Changman said:
"We already choosed old curseg(Y) and then we allocate new address(Z) from old
curseg(Y). After that we call refresh_sit_entry(old address, new address).
In the funcation, we call locate_dirty_segment with old seg and old curseg.
So calling locate_dirty_segment after refresh_sit_entry again is redundant."
Jaegeuk said:
"Right. The new address is always allocated from old_curseg."
Reviewed-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
Signed-off-by: Dongho Sim <dh.sim@xxxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/f2fs/segment.c | 3 ---
1 file changed, 3 deletions(-)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -969,14 +969,12 @@ void allocate_data_block(struct f2fs_sb_
{
struct sit_info *sit_i = SIT_I(sbi);
struct curseg_info *curseg;
- unsigned int old_cursegno;
curseg = CURSEG_I(sbi, type);
mutex_lock(&curseg->curseg_mutex);
*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
- old_cursegno = curseg->segno;
/*
* __add_sum_entry should be resided under the curseg_mutex
@@ -997,7 +995,6 @@ void allocate_data_block(struct f2fs_sb_
* since SSR needs latest valid block information.
*/
refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
- locate_dirty_segment(sbi, old_cursegno);
mutex_unlock(&sit_i->sentry_lock);