Re: [f2fs-dev] [PATCH] f2fs: fix deadlock between quota writes and checkpoint
From: Chao Yu
Date: Tue Aug 04 2020 - 03:57:19 EST
On 2020/8/4 11:54, Jaegeuk Kim wrote:
On 08/04, Chao Yu wrote:
On 2020/7/29 15:02, Jaegeuk Kim wrote:
f2fs_write_data_pages(quota_mapping)
__f2fs_write_data_pages f2fs_write_checkpoint
* blk_start_plug(&plug);
* add bio in write_io[DATA]
- block_operations
- skip syncing quota by
>DEFAULT_RETRY_QUOTA_FLUSH_COUNT
- down_write(&sbi->node_write);
f2fs_flush_merged_writes() will be called after block_operations(), why this doesn't
help?
Well, I think bio can be added after f2fs_flush_merged_writes() as well.
- down_read(node_write)
- f2fs_do_write_data_page
- f2fs_trylock_op
- f2fs_outplace_write_data
- f2fs_submit_page_write
bio only be added under node_write lock? during f2fs_flush_merged_writes(), node_write
should have been held by checkpoint() avoiding quota data writeback & bio submission.
- f2fs_write_single_data_page
- f2fs_do_write_data_page
- f2fs_outplace_write_data
- do_write_page
- f2fs_allocate_data_block
- down_write(node_write)
- f2fs_wait_on_all_pages(F2FS_WB_CP_DATA);
Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8c782d3f324f0..99c8061da55b9 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1269,6 +1269,8 @@ void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type)
if (type == F2FS_DIRTY_META)
f2fs_sync_meta_pages(sbi, META, LONG_MAX,
FS_CP_META_IO);
+ else if (type == F2FS_WB_CP_DATA)
+ f2fs_submit_merged_write(sbi, DATA);
io_schedule_timeout(DEFAULT_IO_TIMEOUT);
}
finish_wait(&sbi->cp_wait, &wait);
.