From patchwork Mon Nov 16 14:57:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 324625 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45FEBC82559 for ; Mon, 16 Nov 2020 15:02:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11138217A0 for ; Mon, 16 Nov 2020 15:02:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="egIiJi4m" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731349AbgKPPCL (ORCPT ); Mon, 16 Nov 2020 10:02:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730947AbgKPO7b (ORCPT ); Mon, 16 Nov 2020 09:59:31 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7043C0613CF; Mon, 16 Nov 2020 06:59:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=utL1e0DdHIY8Fd3lNgkU74rr4MTUuDAaqA4KW/LJ7AI=; b=egIiJi4m0U4Bm5a3xLAsrAucMd 3Y7Dcxn9qZ2xlM77p9BbRtBKAln3LYpke4xFjJKvrfnjmejTmX21aKv6vHUxAkbNTTH9fw7G54xZE Kcbkwh5neJ/WOJ4yHL///KJ52srvgevLbhi3qd1e08YDaRuFP485wS+EsORi6U8MM67Ud6YA6Yo9K bekvmhX/aEn35Ce8tzn7JUsepDG8P/sXuIMbKe85k7vlXKh+ZwG8eqa3IAX5tqQQpbDeZHpRvsm4J aMOADF6lGFN9v0NVt3sH4VO4MQZpaNVbF7K5D8nyCVbFuFBLe2fOC4iaMbbC11Aoh49rz2wPPgNxC Bk30XNJQ==; Received: from [2001:4bb8:180:6600:255b:7def:a93:4a09] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kefyR-00041m-OS; Mon, 16 Nov 2020 14:59:20 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Justin Sanders , Josef Bacik , Ilya Dryomov , Jack Wang , "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Konrad Rzeszutek Wilk , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Minchan Kim , Mike Snitzer , Song Liu , "Martin K. Petersen" , dm-devel@redhat.com, linux-block@vger.kernel.org, drbd-dev@lists.linbit.com, nbd@other.debian.org, ceph-devel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 49/78] ataflop: use a separate gendisk for each media format Date: Mon, 16 Nov 2020 15:57:40 +0100 Message-Id: <20201116145809.410558-50-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201116145809.410558-1-hch@lst.de> References: <20201116145809.410558-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org The Atari floppy driver usually autodetects the media when used with the ormal /dev/fd? devices, which also are the only nodes created by udev. But it also supports various aliases that force a given media format. That is currently supported using the blk_register_region framework which finds the floppy gendisk even for a 'mismatched' dev_t. The problem with this (besides the code complexity) is that it creates multiple struct block_device instances for the whole device of a single gendisk, which can lead to interesting issues in code not aware of that fact. To fix this just create a separate gendisk for each of the aliases if they are accessed. Signed-off-by: Christoph Hellwig --- drivers/block/ataflop.c | 135 +++++++++++++++++++++++++--------------- 1 file changed, 86 insertions(+), 49 deletions(-) diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c index 3e881fdb06e0ad..104b713f4055af 100644 --- a/drivers/block/ataflop.c +++ b/drivers/block/ataflop.c @@ -297,7 +297,7 @@ static struct atari_floppy_struct { unsigned int wpstat; /* current state of WP signal (for disk change detection) */ int flags; /* flags */ - struct gendisk *disk; + struct gendisk *disk[NUM_DISK_MINORS]; int ref; int type; struct blk_mq_tag_set tag_set; @@ -723,12 +723,16 @@ static void fd_error( void ) static int do_format(int drive, int type, struct atari_format_descr *desc) { - struct request_queue *q = unit[drive].disk->queue; + struct request_queue *q; unsigned char *p; int sect, nsect; unsigned long flags; int ret; + if (type) + type--; + + q = unit[drive].disk[type]->queue; blk_mq_freeze_queue(q); blk_mq_quiesce_queue(q); @@ -738,7 +742,7 @@ static int do_format(int drive, int type, struct atari_format_descr *desc) local_irq_restore(flags); if (type) { - if (--type >= NUM_DISK_MINORS || + if (type >= NUM_DISK_MINORS || minor2disktype[type].drive_types > DriveType) { ret = -EINVAL; goto out; @@ -1154,7 +1158,7 @@ static void fd_rwsec_done1(int status) if (SUDT[-1].blocks > ReqBlock) { /* try another disk type */ SUDT--; - set_capacity(unit[SelectedDrive].disk, + set_capacity(unit[SelectedDrive].disk[0], SUDT->blocks); } else Probing = 0; @@ -1169,7 +1173,7 @@ static void fd_rwsec_done1(int status) /* record not found, but not probing. Maybe stretch wrong ? Restart probing */ if (SUD.autoprobe) { SUDT = atari_disk_type + StartDiskType[DriveType]; - set_capacity(unit[SelectedDrive].disk, + set_capacity(unit[SelectedDrive].disk[0], SUDT->blocks); Probing = 1; } @@ -1515,7 +1519,7 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, if (!UDT) { Probing = 1; UDT = atari_disk_type + StartDiskType[DriveType]; - set_capacity(floppy->disk, UDT->blocks); + set_capacity(bd->rq->rq_disk, UDT->blocks); UD.autoprobe = 1; } } @@ -1533,7 +1537,7 @@ static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx, } type = minor2disktype[type].index; UDT = &atari_disk_type[type]; - set_capacity(floppy->disk, UDT->blocks); + set_capacity(bd->rq->rq_disk, UDT->blocks); UD.autoprobe = 0; } @@ -1658,7 +1662,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, printk (KERN_INFO "floppy%d: setting %s %p!\n", drive, dtp->name, dtp); UDT = dtp; - set_capacity(floppy->disk, UDT->blocks); + set_capacity(disk, UDT->blocks); if (cmd == FDDEFPRM) { /* save settings as permanent default type */ @@ -1702,7 +1706,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, return -EINVAL; UDT = dtp; - set_capacity(floppy->disk, UDT->blocks); + set_capacity(disk, UDT->blocks); return 0; case FDMSGON: @@ -1725,7 +1729,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, UDT = NULL; /* MSch: invalidate default_params */ default_params[drive].blocks = 0; - set_capacity(floppy->disk, MAX_DISK_SIZE * 2); + set_capacity(disk, MAX_DISK_SIZE * 2); fallthrough; case FDFMTEND: case FDFLUSH: @@ -1962,14 +1966,50 @@ static const struct blk_mq_ops ataflop_mq_ops = { .commit_rqs = ataflop_commit_rqs, }; -static struct kobject *floppy_find(dev_t dev, int *part, void *data) +static int ataflop_alloc_disk(unsigned int drive, unsigned int type) { - int drive = *part & 3; - int type = *part >> 2; + struct gendisk *disk; + int ret; + + disk = alloc_disk(1); + if (!disk) + return -ENOMEM; + + disk->queue = blk_mq_init_queue(&unit[drive].tag_set); + if (IS_ERR(disk->queue)) { + ret = PTR_ERR(disk->queue); + disk->queue = NULL; + put_disk(disk); + return ret; + } + + disk->major = FLOPPY_MAJOR; + disk->first_minor = drive + (type << 2); + sprintf(disk->disk_name, "fd%d", drive); + disk->fops = &floppy_fops; + disk->events = DISK_EVENT_MEDIA_CHANGE; + disk->private_data = &unit[drive]; + set_capacity(disk, MAX_DISK_SIZE * 2); + + unit[drive].disk[type] = disk; + return 0; +} + +static DEFINE_MUTEX(ataflop_probe_lock); + +static void ataflop_probe(dev_t dev) +{ + int drive = MINOR(dev) & 3; + int type = MINOR(dev) >> 2; + if (drive >= FD_MAX_UNITS || type > NUM_DISK_MINORS) - return NULL; - *part = 0; - return get_disk_and_module(unit[drive].disk); + return; + mutex_lock(&ataflop_probe_lock); + if (!unit[drive].disk[type]) { + if (ataflop_alloc_disk(drive, type) == 0) + add_disk(unit[drive].disk[type]); + } + mutex_unlock(&ataflop_probe_lock); } static int __init atari_floppy_init (void) @@ -1981,23 +2021,26 @@ static int __init atari_floppy_init (void) /* Amiga, Mac, ... don't have Atari-compatible floppy :-) */ return -ENODEV; - if (register_blkdev(FLOPPY_MAJOR,"fd")) - return -EBUSY; + mutex_lock(&ataflop_probe_lock); + ret = __register_blkdev(FLOPPY_MAJOR, "fd", ataflop_probe); + if (ret) + goto out_unlock; for (i = 0; i < FD_MAX_UNITS; i++) { - unit[i].disk = alloc_disk(1); - if (!unit[i].disk) { - ret = -ENOMEM; + memset(&unit[i].tag_set, 0, sizeof(unit[i].tag_set)); + unit[i].tag_set.ops = &ataflop_mq_ops; + unit[i].tag_set.nr_hw_queues = 1; + unit[i].tag_set.nr_maps = 1; + unit[i].tag_set.queue_depth = 2; + unit[i].tag_set.numa_node = NUMA_NO_NODE; + unit[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE; + ret = blk_mq_alloc_tag_set(&unit[i].tag_set); + if (ret) goto err; - } - unit[i].disk->queue = blk_mq_init_sq_queue(&unit[i].tag_set, - &ataflop_mq_ops, 2, - BLK_MQ_F_SHOULD_MERGE); - if (IS_ERR(unit[i].disk->queue)) { - put_disk(unit[i].disk); - ret = PTR_ERR(unit[i].disk->queue); - unit[i].disk->queue = NULL; + ret = ataflop_alloc_disk(i, 0); + if (ret) { + blk_mq_free_tag_set(&unit[i].tag_set); goto err; } } @@ -2027,19 +2070,9 @@ static int __init atari_floppy_init (void) for (i = 0; i < FD_MAX_UNITS; i++) { unit[i].track = -1; unit[i].flags = 0; - unit[i].disk->major = FLOPPY_MAJOR; - unit[i].disk->first_minor = i; - sprintf(unit[i].disk->disk_name, "fd%d", i); - unit[i].disk->fops = &floppy_fops; - unit[i].disk->events = DISK_EVENT_MEDIA_CHANGE; - unit[i].disk->private_data = &unit[i]; - set_capacity(unit[i].disk, MAX_DISK_SIZE * 2); - add_disk(unit[i].disk); + add_disk(unit[i].disk[0]); } - blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE, - floppy_find, NULL, NULL); - printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n", DriveType == 0 ? 'D' : DriveType == 1 ? 'H' : 'E', UseTrackbuffer ? "" : "no "); @@ -2049,14 +2082,14 @@ static int __init atari_floppy_init (void) err: while (--i >= 0) { - struct gendisk *disk = unit[i].disk; - - blk_cleanup_queue(disk->queue); + blk_cleanup_queue(unit[i].disk[0]->queue); + put_disk(unit[i].disk[0]); blk_mq_free_tag_set(&unit[i].tag_set); - put_disk(unit[i].disk); } unregister_blkdev(FLOPPY_MAJOR, "fd"); +out_unlock: + mutex_unlock(&ataflop_probe_lock); return ret; } @@ -2101,13 +2134,17 @@ __setup("floppy=", atari_floppy_setup); static void __exit atari_floppy_exit(void) { - int i; - blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256); + int i, type; + for (i = 0; i < FD_MAX_UNITS; i++) { - del_gendisk(unit[i].disk); - blk_cleanup_queue(unit[i].disk->queue); + for (type = 0; type < NUM_DISK_MINORS; type++) { + if (!unit[i].disk[type]) + continue; + del_gendisk(unit[i].disk[type]); + blk_cleanup_queue(unit[i].disk[type]->queue); + put_disk(unit[i].disk[type]); + } blk_mq_free_tag_set(&unit[i].tag_set); - put_disk(unit[i].disk); } unregister_blkdev(FLOPPY_MAJOR, "fd");