From patchwork Mon Nov 15 16:58:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 12620219 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58AB0C433FE for ; Mon, 15 Nov 2021 18:53:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3847F6363E for ; Mon, 15 Nov 2021 18:53:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243245AbhKOS4V (ORCPT ); Mon, 15 Nov 2021 13:56:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:55938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243094AbhKOSxo (ORCPT ); Mon, 15 Nov 2021 13:53:44 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5662A6347A; Mon, 15 Nov 2021 18:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636999844; bh=XjXIU3AqPDWK1zsJOZsPevZkNoJfHbMwTbUH/TcPL1c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=quOzWzrQTo+wliy0jLE0wdKwvdp6dKAHPxfPRR29pAaZv8EFntS9Alvkgmcmxi77k gmc865+TftgV2u9Y4iYK7884fTnwiwMl7cMUyL4hvPQkn6008UUYxkBADCIkPZ9vRy 6R5qedTUV6QVxHoPorcvKdxEuXpoiyiHA2TYdbwk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Schmitz , linux-block@vger.kernel.org, Tetsuo Handa , Jens Axboe , Sasha Levin Subject: [PATCH 5.14 444/849] block: ataflop: fix breakage introduced at blk-mq refactoring Date: Mon, 15 Nov 2021 17:58:47 +0100 Message-Id: <20211115165435.298027726@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165419.961798833@linuxfoundation.org> References: <20211115165419.961798833@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Michael Schmitz [ Upstream commit 86d46fdaa12ae5befc16b8d73fc85a3ca0399ea6 ] Refactoring of the Atari floppy driver when converting to blk-mq has broken the state machine in not-so-subtle ways: finish_fdc() must be called when operations on the floppy device have completed. This is crucial in order to relase the ST-DMA lock, which protects against concurrent access to the ST-DMA controller by other drivers (some DMA related, most just related to device register access - broken beyond compare, I know). When rewriting the driver's old do_request() function, the fact that finish_fdc() was called only when all queued requests had completed appears to have been overlooked. Instead, the new request function calls finish_fdc() immediately after the last request has been queued. finish_fdc() executes a dummy seek after most requests, and this overwrites the state machine's interrupt hander that was set up to wait for completion of the read/write request just prior. To make matters worse, finish_fdc() is called before device interrupts are re-enabled, making certain that the read/write interupt is missed. Shifting the finish_fdc() call into the read/write request completion handler ensures the driver waits for the request to actually complete. With a queue depth of 2, we won't see long request sequences, so calling finish_fdc() unconditionally just adds a little overhead for the dummy seeks, and keeps the code simple. While we're at it, kill ataflop_commit_rqs() which does nothing but run finish_fdc() unconditionally, again likely wiping out an in-flight request. Signed-off-by: Michael Schmitz Fixes: 6ec3938cff95 ("ataflop: convert to blk-mq") CC: linux-block@vger.kernel.org CC: Tetsuo Handa Link: https://lore.kernel.org/r/20211019061321.26425-1-schmitzmic@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/ataflop.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index a093644ac39fb..bbb64331cf8f4 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -653,9 +653,6 @@ static inline void copy_buffer(void *from, void *to) *p2++ = *p1++; } - - - /* General Interrupt Handling */ static void (*FloppyIRQHandler)( int status ) = NULL; @@ -1228,6 +1225,7 @@ static void fd_rwsec_done1(int status) } else { /* all sectors finished */ + finish_fdc(); fd_end_request_cur(BLK_STS_OK); } return; @@ -1475,15 +1473,6 @@ static void setup_req_params( int drive ) ReqTrack, ReqSector, (unsigned long)ReqData )); } -static void ataflop_commit_rqs(struct blk_mq_hw_ctx *hctx) -{ - spin_lock_irq(&ataflop_lock); - atari_disable_irq(IRQ_MFP_FDC); - finish_fdc(); - atari_enable_irq(IRQ_MFP_FDC); - spin_unlock_irq(&ataflop_lock); -} - static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { @@ -1491,6 +1480,8 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, int drive = floppy - unit; int type = floppy->type; + DPRINT(("Queue request: drive %d type %d last %d\n", drive, type, bd->last)); + spin_lock_irq(&ataflop_lock); if (fd_request) { spin_unlock_irq(&ataflop_lock); @@ -1550,8 +1541,6 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, setup_req_params( drive ); do_fd_action( drive ); - if (bd->last) - finish_fdc(); atari_enable_irq( IRQ_MFP_FDC ); out: @@ -1962,7 +1951,6 @@ static const struct block_device_operations floppy_fops = { static const struct blk_mq_ops ataflop_mq_ops = { .queue_rq = ataflop_queue_rq, - .commit_rqs = ataflop_commit_rqs, }; static int ataflop_alloc_disk(unsigned int drive, unsigned int type) From patchwork Mon Nov 15 16:59:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 12620221 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 079F4C433FE for ; Mon, 15 Nov 2021 18:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF85161AF0 for ; Mon, 15 Nov 2021 18:58:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243464AbhKOTBI (ORCPT ); Mon, 15 Nov 2021 14:01:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:59670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243487AbhKOS7x (ORCPT ); Mon, 15 Nov 2021 13:59:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CC62661AF0; Mon, 15 Nov 2021 18:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637000018; bh=FUUzhV0aQZHF45SsL1ZUN80Nlr/CDWDn2vwQsaJOprA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=txSQUiLHLMPauq79XP83qM40+deBMJKNZBbzNgC0Lo3Cx2koho3l2AlbKaZoVFyLd ZdP2dkWfNKseSJkhHH/fDvn5ueIFSYuozsZdijrqZcz3TO6ry8KHWsJ9bQjsYFwLDG p8VR/ZjsalLu0pqGYO451WL52EuYjqqdCi0uaMaI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Schmitz , linux-block@vger.kernel.org, Jens Axboe , Sasha Levin Subject: [PATCH 5.14 508/849] block: ataflop: more blk-mq refactoring fixes Date: Mon, 15 Nov 2021 17:59:51 +0100 Message-Id: <20211115165437.471352298@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165419.961798833@linuxfoundation.org> References: <20211115165419.961798833@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Michael Schmitz [ Upstream commit d28e4dff085c5a87025c9a0a85fb798bd8e9ca17 ] 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 Fixes: 6ec3938cff95f (ataflop: convert to blk-mq) CC: linux-block@vger.kernel.org Link: https://lore.kernel.org/r/20211024002013.9332-1-schmitzmic@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/ataflop.c | 45 +++++++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 6 deletions(-) diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index bbb64331cf8f4..4947e41f89b7d 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -456,10 +456,20 @@ static DEFINE_TIMER(fd_timer, check_change); 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 ); } @@ -729,8 +748,10 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) if (type) { type--; if (type >= NUM_DISK_MINORS || - minor2disktype[type].drive_types > DriveType) + minor2disktype[type].drive_types > DriveType) { + finish_fdc(); return -EINVAL; + } } q = unit[drive].disk[type]->queue; @@ -748,6 +769,7 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) } if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) { + finish_fdc(); ret = -EINVAL; goto out; } @@ -788,6 +810,7 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) wait_for_completion(&format_wait); + finish_fdc(); ret = FormatError ? -EIO : 0; out: blk_mq_unquiesce_queue(q); @@ -822,6 +845,7 @@ static void do_fd_action( int drive ) else { /* all sectors finished */ fd_end_request_cur(BLK_STS_OK); + finish_fdc(); return; } } @@ -1225,8 +1249,8 @@ static void fd_rwsec_done1(int status) } else { /* all sectors finished */ - finish_fdc(); fd_end_request_cur(BLK_STS_OK); + finish_fdc(); } return; @@ -1348,7 +1372,7 @@ static void fd_times_out(struct timer_list *unused) static void finish_fdc( void ) { - if (!NeedSeek) { + if (!NeedSeek || !stdma_is_locked_by(floppy_irq)) { finish_fdc_done( 0 ); } else { @@ -1383,7 +1407,8 @@ 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")); @@ -1480,7 +1505,9 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, 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) { @@ -1502,6 +1529,7 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, /* drive not connected */ printk(KERN_ERR "Unknown Device: fd%d\n", drive ); fd_end_request_cur(BLK_STS_IOERR); + stdma_release(); goto out; } @@ -1518,11 +1546,13 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, 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; @@ -1623,6 +1653,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, /* what if type > 0 here? Overwrite specified entry ? */ if (type) { /* refuse to re-set a predefined type for now */ + finish_fdc(); return -EINVAL; } @@ -1690,8 +1721,10 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, /* sanity check */ if (setprm.track != dtp->blocks/dtp->spt/2 || - setprm.head != 2) + setprm.head != 2) { + finish_fdc(); return -EINVAL; + } UDT = dtp; set_capacity(disk, UDT->blocks);