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| author | Christoph Hellwig <hch@lst.de> | 2015-09-27 21:01:50 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-10-01 10:10:55 +0200 |
| commit | f4829a9b7a61e159367350008a608b062c4f6840 (patch) | |
| tree | a2f488a95324e0c0b558273f48b18413ab2fa221 /drivers/block/loop.c | |
| parent | 60de074ba1e8f327db19bc33d8530131ac01695d (diff) | |
| download | linux-f4829a9b7a61e159367350008a608b062c4f6840.tar.gz linux-f4829a9b7a61e159367350008a608b062c4f6840.tar.bz2 linux-f4829a9b7a61e159367350008a608b062c4f6840.zip | |
blk-mq: fix racy updates of rq->errors
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.
Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/loop.c')
| -rw-r--r-- | drivers/block/loop.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index f9889b6bc02c..674f800a3b57 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1486,17 +1486,16 @@ static void loop_handle_cmd(struct loop_cmd *cmd) { const bool write = cmd->rq->cmd_flags & REQ_WRITE; struct loop_device *lo = cmd->rq->q->queuedata; - int ret = -EIO; + int ret = 0; - if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) + if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { + ret = -EIO; goto failed; + } ret = do_req_filebacked(lo, cmd->rq); - failed: - if (ret) - cmd->rq->errors = -EIO; - blk_mq_complete_request(cmd->rq); + blk_mq_complete_request(cmd->rq, ret ? -EIO : 0); } static void loop_queue_write_work(struct work_struct *work) |