From: Dongho Sim Date: Wed, 30 Jul 2014 06:52:41 +0000 (+0000) Subject: f2fs: remove redundant lines in allocate_data_block X-Git-Tag: firefly_0821_release~176^2~3488^2~7 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=33be828ada7274ebcade2001f16e5b4e33a4636e;p=firefly-linux-kernel-4.4.55.git f2fs: remove redundant lines in allocate_data_block 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 Signed-off-by: Dongho Sim Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 5a53a0ac6e4f..c3b76d091450 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -976,14 +976,12 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, { 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 @@ -1004,7 +1002,6 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, * 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);