5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Schmitz <schmitzmic@xxxxxxxxx> 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@xxxxxxxxx> Fixes: 6ec3938cff95f (ataflop: convert to blk-mq) CC: linux-block@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20211024002013.9332-1-schmitzmic@xxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> [MSch: v5.10 backport merge conflict fix] Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/ataflop.c | 42 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 37 insertions(+), 5 deletions(-) --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -456,10 +456,20 @@ static DEFINE_TIMER(fd_timer, check_chan static void fd_end_request_cur(blk_status_t err) { + DPRINT(("fd_end_request_cur(), bytes %d of %d\n", + blk_rq_cur_bytes(fd_request), + blk_rq_bytes(fd_request))); + if (!blk_update_request(fd_request, err, blk_rq_cur_bytes(fd_request))) { + DPRINT(("calling __blk_mq_end_request()\n")); __blk_mq_end_request(fd_request, err); fd_request = NULL; + } else { + /* requeue rest of request */ + DPRINT(("calling blk_mq_requeue_request()\n")); + blk_mq_requeue_request(fd_request, true); + fd_request = NULL; } } @@ -697,12 +707,21 @@ static void fd_error( void ) if (fd_request->error_count >= MAX_ERRORS) { printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive ); fd_end_request_cur(BLK_STS_IOERR); + finish_fdc(); + return; } else if (fd_request->error_count == RECALIBRATE_ERRORS) { printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive ); if (SelectedDrive != -1) SUD.track = -1; } + /* need to re-run request to recalibrate */ + atari_disable_irq( IRQ_MFP_FDC ); + + setup_req_params( SelectedDrive ); + do_fd_action( SelectedDrive ); + + atari_enable_irq( IRQ_MFP_FDC ); } @@ -737,6 +756,7 @@ static int do_format(int drive, int type if (type) { if (--type >= NUM_DISK_MINORS || minor2disktype[type].drive_types > DriveType) { + finish_fdc(); ret = -EINVAL; goto out; } @@ -745,6 +765,7 @@ static int do_format(int drive, int type } if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) { + finish_fdc(); ret = -EINVAL; goto out; } @@ -785,6 +806,7 @@ static int do_format(int drive, int type wait_for_completion(&format_wait); + finish_fdc(); ret = FormatError ? -EIO : 0; out: blk_mq_unquiesce_queue(q); @@ -819,6 +841,7 @@ static void do_fd_action( int drive ) else { /* all sectors finished */ fd_end_request_cur(BLK_STS_OK); + finish_fdc(); return; } } @@ -1222,8 +1245,8 @@ static void fd_rwsec_done1(int status) } else { /* all sectors finished */ - finish_fdc(); fd_end_request_cur(BLK_STS_OK); + finish_fdc(); } return; @@ -1345,7 +1368,7 @@ static void fd_times_out(struct timer_li static void finish_fdc( void ) { - if (!NeedSeek) { + if (!NeedSeek || !stdma_is_locked_by(floppy_irq)) { finish_fdc_done( 0 ); } else { @@ -1380,7 +1403,8 @@ static void finish_fdc_done( int dummy ) start_motor_off_timer(); local_irq_save(flags); - stdma_release(); + if (stdma_is_locked_by(floppy_irq)) + stdma_release(); local_irq_restore(flags); DPRINT(("finish_fdc() finished\n")); @@ -1477,7 +1501,9 @@ static blk_status_t ataflop_queue_rq(str int drive = floppy - unit; int type = floppy->type; - DPRINT(("Queue request: drive %d type %d last %d\n", drive, type, bd->last)); + DPRINT(("Queue request: drive %d type %d sectors %d of %d last %d\n", + drive, type, blk_rq_cur_sectors(bd->rq), + blk_rq_sectors(bd->rq), bd->last)); spin_lock_irq(&ataflop_lock); if (fd_request) { @@ -1499,6 +1525,7 @@ static blk_status_t ataflop_queue_rq(str /* drive not connected */ printk(KERN_ERR "Unknown Device: fd%d\n", drive ); fd_end_request_cur(BLK_STS_IOERR); + stdma_release(); goto out; } @@ -1515,11 +1542,13 @@ static blk_status_t ataflop_queue_rq(str if (--type >= NUM_DISK_MINORS) { printk(KERN_WARNING "fd%d: invalid disk format", drive ); fd_end_request_cur(BLK_STS_IOERR); + stdma_release(); goto out; } if (minor2disktype[type].drive_types > DriveType) { printk(KERN_WARNING "fd%d: unsupported disk format", drive ); fd_end_request_cur(BLK_STS_IOERR); + stdma_release(); goto out; } type = minor2disktype[type].index; @@ -1620,6 +1649,7 @@ static int fd_locked_ioctl(struct block_ /* what if type > 0 here? Overwrite specified entry ? */ if (type) { /* refuse to re-set a predefined type for now */ + finish_fdc(); return -EINVAL; } @@ -1687,8 +1717,10 @@ static int fd_locked_ioctl(struct block_ /* sanity check */ if (setprm.track != dtp->blocks/dtp->spt/2 || - setprm.head != 2) + setprm.head != 2) { + finish_fdc(); return -EINVAL; + } UDT = dtp; set_capacity(floppy->disk, UDT->blocks);
