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| author | Chao Yu <yuchao0@huawei.com> | 2016-07-07 14:46:55 (GMT) |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2016-07-08 17:33:34 (GMT) |
| commit | c24a0fd655431e9f14c8a8754d0a6cc247f9e9e5 (patch) | |
| tree | 2005086755d7b0f14bf706eadaa0c3fd4300a5f5 /fs/f2fs | |
| parent | c7b41e161368388487238d71986a65290f83d74a (diff) | |
| download | linux-c24a0fd655431e9f14c8a8754d0a6cc247f9e9e5.tar.xz | |
f2fs: fix to avoid redundant discard during fstrim
With below test steps, f2fs will issue redundant discard when doing fstrim,
the reason is that we issue discards for both prefree segments and
consecutive freed region user wants to trim, part regions they covered are
overlapped, here, we change to do not to issue any discards for prefree
segments in trimmed range.
1. mount -t f2fs -o discard /dev/zram0 /mnt/f2fs
2. fstrim -o 0 -l 3221225472 -m 2097152 -v /mnt/f2fs/
3. dd if=/dev/zero of=/mnt/f2fs/a bs=2M count=1
4. dd if=/dev/zero of=/mnt/f2fs/b bs=1M count=1
5. sync
6. rm /mnt/f2fs/a /mnt/f2fs/b
7. fstrim -o 0 -l 3221225472 -m 2097152 -v /mnt/f2fs/
Before:
<...>-5428 [001] ...1 9511.052125: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x200
<...>-5428 [001] ...1 9511.052787: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x300
After:
<...>-6764 [000] ...1 9720.382504: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x300
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/segment.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 9e13db0..08f6c0b 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -714,6 +714,7 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc) unsigned long *prefree_map = dirty_i->dirty_segmap[PRE]; unsigned int start = 0, end = -1; unsigned int secno, start_segno; + bool force = (cpc->reason == CP_DISCARD); mutex_lock(&dirty_i->seglist_lock); @@ -730,7 +731,7 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc) dirty_i->nr_dirty[PRE] -= end - start; - if (!test_opt(sbi, DISCARD)) + if (force || !test_opt(sbi, DISCARD)) continue; if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) { @@ -754,7 +755,7 @@ next: /* send small discards */ list_for_each_entry_safe(entry, this, head, list) { - if (cpc->reason == CP_DISCARD && entry->len < cpc->trim_minlen) + if (force && entry->len < cpc->trim_minlen) goto skip; f2fs_issue_discard(sbi, entry->blkaddr, entry->len); cpc->trimmed += entry->len; |