On Tue, Feb 27, 2024 at 02:37:28PM +1300, Michael Schmitz wrote:
[ commit d28e4dff085c5a87025c9a0a85fb798bd8e9ca17 upstream ]
As it turns out, my earlier patch in commit 86d46fdaa12a (block: ataflop: fix breakage introduced at blk-mq refactoring) was incomplete. This patch fixes any remaining issues found during more testing and code review.
Requests exceeding 4 k are handled in 4k segments but __blk_mq_end_request() is never called on these (still sectors outstanding on the request). With redo_fd_request() removed, there is no provision to kick off processing of the next segment, causing requests exceeding 4k to hang. (By setting /sys/block/fd0/queue/max_sectors_k <= 4 as workaround, this behaviour can be avoided).
Instead of reintroducing redo_fd_request(), requeue the remainder of the request by calling blk_mq_requeue_request() on incomplete requests (i.e. when blk_update_request() still returns true), and rely on the block layer to queue the residual as new request.
Both error handling and formatting needs to release the ST-DMA lock, so call finish_fdc() on these (this was previously handled by redo_fd_request()). finish_fdc() may be called legitimately without the ST-DMA lock held - make sure we only release the lock if we actually held it. In a similar way, early exit due to errors in ataflop_queue_rq() must release the lock.
After minor errors, fd_error sets up to recalibrate the drive but never re-runs the current operation (another task handled by redo_fd_request() before). Call do_fd_action() to get the next steps (seek, retry read/write) underway.
Signed-off-by: Michael Schmitz schmitzmic@gmail.com Fixes: 6ec3938cff95f (ataflop: convert to blk-mq) Fixes: 86d46fdaa12a (block: ataflop: fix breakage introduced at blk-mq refactoring) CC: stable@vger.kernel.org # 5.10.x Link: https://lore.kernel.org/r/20211024002013.9332-1-schmitzmic@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk [MSch: v5.10 backport merge conflict fix]
Now queued up, thanks.
greg k-h