How? Can the invalid blocks of file A be discarded, if file B is alive
all the time and fggc_threshold is 507 ?
On 2017/8/28 17:59, Chao Yu wrote:
On 2017/8/26 20:49, Yunlong Song wrote:
1. write file A with 5 blocks to current empty active segment
2. remove file A
3. write checkpoint
4. write file B with 507 blocks to the same active segment
If file B is alive all the time, the blocks used by file A will never be
discarded. So current active segment should also be treated as a candidate
for small discards.
I don't think that would be a big issue, since there will not be any freezing
log headers, once log header moves, later invalid blocks could be discarded.
Thanks,
Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
---
fs/f2fs/segment.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8375257..a2e7c8f 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1339,7 +1339,9 @@ static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
return false;
if (!force) {
- if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
+ if (!test_opt(sbi, DISCARD) ||
+ (!se->valid_blocks &&
+ !IS_CURSEG(sbi, cpc->trim_start)) ||
SM_I(sbi)->dcc_info->nr_discards >=
SM_I(sbi)->dcc_info->max_discards)
return false;
.
--
Thanks,
Yunlong Song
