| From: Jack Qiu <jack.qiu@huawei.com> |
| Subject: fs: direct-io: fix missing sdio->boundary |
| |
| I encountered a hung task issue, but not a performance one. I run DIO |
| on a device (need lba continuous, for example open channel ssd), maybe |
| hungtask in below case: |
| |
| DIO: Checkpoint: |
| get addr A(at boundary), merge into BIO, |
| no submit because boundary missing |
| flush dirty data(get addr A+1), wait IO(A+1) |
| writeback timeout, because DIO(A) didn't submit |
| get addr A+2 fail, because checkpoint is doing |
| |
| |
| dio_send_cur_page() may clear sdio->boundary, so prevent it from |
| missing a boundary. |
| |
| Link: https://lkml.kernel.org/r/20210322042253.38312-1-jack.qiu@huawei.com |
| Fixes: b1058b981272 ("direct-io: submit bio after boundary buffer is |
| added to it") |
| Signed-off-by: Jack Qiu <jack.qiu@huawei.com> |
| Reviewed-by: Jan Kara <jack@suse.cz> |
| Cc: <stable@vger.kernel.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| fs/direct-io.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/fs/direct-io.c~fs-direct-io-fix-missing-sdio-boundary |
| +++ a/fs/direct-io.c |
| @@ -812,6 +812,7 @@ submit_page_section(struct dio *dio, str |
| struct buffer_head *map_bh) |
| { |
| int ret = 0; |
| + int boundary = sdio->boundary; /* dio_send_cur_page may clear it */ |
| |
| if (dio->op == REQ_OP_WRITE) { |
| /* |
| @@ -850,10 +851,10 @@ submit_page_section(struct dio *dio, str |
| sdio->cur_page_fs_offset = sdio->block_in_file << sdio->blkbits; |
| out: |
| /* |
| - * If sdio->boundary then we want to schedule the IO now to |
| + * If boundary then we want to schedule the IO now to |
| * avoid metadata seeks. |
| */ |
| - if (sdio->boundary) { |
| + if (boundary) { |
| ret = dio_send_cur_page(dio, sdio, map_bh); |
| if (sdio->bio) |
| dio_bio_submit(dio, sdio); |
| _ |
