From patchwork Wed Feb 9 08:21:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541648 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 933DCC433F5 for ; Wed, 9 Feb 2022 08:21:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238739AbiBIIVb (ORCPT ); Wed, 9 Feb 2022 03:21:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239591AbiBIIVa (ORCPT ); Wed, 9 Feb 2022 03:21:30 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C137CC05CB82; Wed, 9 Feb 2022 00:21:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=Sw3T8I6YXMWb2jiqB7QUc/okYU5X2+bEkOeoAGfg6Ak=; b=zvIdqvijwOa1CZXt0/IX+bv8Ck FepyGnk9TVxolqz848lYLqSdrWdjoH71qYc4Qrkcg++Hungn2BIXlP4IYQP3xpav/hRyNJlqmsOoH GYu4BK0BNBLyCKJN8Gr/ES9P2pF7lmlkacAStU2MaVHc61n7BzEi1Tz4Kn8SjR9jyJZArJ9cpcuVY g1zOyniqKaE9Aq3WY3MUdK4gWDdTwgJyU5eVVseBYufGL6eRRDV1H1fKp5M0pCWaneJS/+HAgSwLE /gPnJ1eJlPuaqhKAvZ0VYkv8rMYlNIQFXIjgEWqAt4q8KLT0I80W/5dm9nscbzMBUYDYSN+EXuokJ p4GQIpBQ==; Received: from [2001:4bb8:188:3efc:ea2:7599:7eeb:4b5a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHiEB-00GbAb-72; Wed, 09 Feb 2022 08:21:27 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 1/5] block: add a ->free_disk method Date: Wed, 9 Feb 2022 09:21:16 +0100 Message-Id: <20220209082121.2628452-2-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Add a method to notify the driver that the gendisk is about to be freed. This allows drivers to tie the lifetime of their private data to that of the gendisk and thus deal with device removal races without expensive synchronization and boilerplate code. Signed-off-by: Christoph Hellwig --- block/genhd.c | 4 ++++ include/linux/blkdev.h | 1 + 2 files changed, 5 insertions(+) diff --git a/block/genhd.c b/block/genhd.c index 9589d1d59afab..1a650c55d7626 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1119,6 +1119,10 @@ static void disk_release(struct device *dev) xa_destroy(&disk->part_tbl); disk->queue->disk = NULL; blk_put_queue(disk->queue); + + if (disk->fops->free_disk) + disk->fops->free_disk(disk); + iput(disk->part0->bd_inode); /* frees the disk */ } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3bfc75a2a4509..a8f8aa4671037 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1464,6 +1464,7 @@ struct block_device_operations { void (*unlock_native_capacity) (struct gendisk *); int (*getgeo)(struct block_device *, struct hd_geometry *); int (*set_read_only)(struct block_device *bdev, bool ro); + void (*free_disk)(struct gendisk *disk); /* this callback is with swap_lock and sometimes page table lock held */ void (*swap_slot_free_notify) (struct block_device *, unsigned long); int (*report_zones)(struct gendisk *, sector_t sector, From patchwork Wed Feb 9 08:21:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541313 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1A80C43219 for ; Wed, 9 Feb 2022 08:21:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240916AbiBIIVg (ORCPT ); Wed, 9 Feb 2022 03:21:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239591AbiBIIVf (ORCPT ); Wed, 9 Feb 2022 03:21:35 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72B16C05CB82; Wed, 9 Feb 2022 00:21:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=Ilg8MRKs3UhBiK+Mujp47+wrzj58nCf6OMRjMHqSUG8=; b=0HfqCHi/cYkXl1l44ziZ7rH0fD Q4o5faCZ0mTKlDobx/Mos2uvSD+rwL7LJ2xFjtWXRf4W+6pPSdvlC2PJEYSvKrtizdXZk8HrRgGpo 9LOMTBrvWN6yoWxB/zbA460GhB9azcRUyKtqhGbIy3dSQOK5ezCLIgzA+dYahk2wQM2G05CiSviyO 6O9LAWp7c+aheeQqmb41PV4X3J40wdXWHw4zGoGBInziqgjXfZ9z8zd05pl7Nmw257SFvE6jR+993 WDtmBeiNVtWuHiXMGNWgXkT0zpHq0LG0pdszYL7njlonHr4rShgsi+vIqXeLPh32IDFvbPqP7o1f/ wtCQJgKw==; Received: from [2001:4bb8:188:3efc:ea2:7599:7eeb:4b5a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHiEE-00GbB7-5O; Wed, 09 Feb 2022 08:21:30 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 2/5] memstick/ms_block: simplify refcounting Date: Wed, 9 Feb 2022 09:21:17 +0100 Message-Id: <20220209082121.2628452-3-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Implement the ->free_disk method to free the msb_data structure only once the last gendisk reference goes away instead of keeping a local refcount. Signed-off-by: Christoph Hellwig --- drivers/memstick/core/ms_block.c | 64 ++++++++------------------------ drivers/memstick/core/ms_block.h | 1 - 2 files changed, 15 insertions(+), 50 deletions(-) diff --git a/drivers/memstick/core/ms_block.c b/drivers/memstick/core/ms_block.c index 0cda6c6baefc3..3993bdd4b519c 100644 --- a/drivers/memstick/core/ms_block.c +++ b/drivers/memstick/core/ms_block.c @@ -1943,22 +1943,6 @@ static void msb_io_work(struct work_struct *work) static DEFINE_IDR(msb_disk_idr); /*set of used disk numbers */ static DEFINE_MUTEX(msb_disk_lock); /* protects against races in open/release */ -static int msb_bd_open(struct block_device *bdev, fmode_t mode) -{ - struct gendisk *disk = bdev->bd_disk; - struct msb_data *msb = disk->private_data; - - dbg_verbose("block device open"); - - mutex_lock(&msb_disk_lock); - - if (msb && msb->card) - msb->usage_count++; - - mutex_unlock(&msb_disk_lock); - return 0; -} - static void msb_data_clear(struct msb_data *msb) { kfree(msb->boot_page); @@ -1968,33 +1952,6 @@ static void msb_data_clear(struct msb_data *msb) msb->card = NULL; } -static int msb_disk_release(struct gendisk *disk) -{ - struct msb_data *msb = disk->private_data; - - dbg_verbose("block device release"); - mutex_lock(&msb_disk_lock); - - if (msb) { - if (msb->usage_count) - msb->usage_count--; - - if (!msb->usage_count) { - disk->private_data = NULL; - idr_remove(&msb_disk_idr, msb->disk_id); - put_disk(disk); - kfree(msb); - } - } - mutex_unlock(&msb_disk_lock); - return 0; -} - -static void msb_bd_release(struct gendisk *disk, fmode_t mode) -{ - msb_disk_release(disk); -} - static int msb_bd_getgeo(struct block_device *bdev, struct hd_geometry *geo) { @@ -2003,6 +1960,17 @@ static int msb_bd_getgeo(struct block_device *bdev, return 0; } +static void msb_bd_free_disk(struct gendisk *disk) +{ + struct msb_data *msb = disk->private_data; + + mutex_lock(&msb_disk_lock); + idr_remove(&msb_disk_idr, msb->disk_id); + mutex_unlock(&msb_disk_lock); + + kfree(msb); +} + static blk_status_t msb_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { @@ -2096,10 +2064,9 @@ static void msb_start(struct memstick_dev *card) } static const struct block_device_operations msb_bdops = { - .open = msb_bd_open, - .release = msb_bd_release, - .getgeo = msb_bd_getgeo, - .owner = THIS_MODULE + .owner = THIS_MODULE, + .getgeo = msb_bd_getgeo, + .free_disk = msb_bd_free_disk, }; static const struct blk_mq_ops msb_mq_ops = { @@ -2147,7 +2114,6 @@ static int msb_init_disk(struct memstick_dev *card) set_capacity(msb->disk, capacity); dbg("Set total disk size to %lu sectors", capacity); - msb->usage_count = 1; msb->io_queue = alloc_ordered_workqueue("ms_block", WQ_MEM_RECLAIM); INIT_WORK(&msb->io_work, msb_io_work); sg_init_table(msb->prealloc_sg, MS_BLOCK_MAX_SEGS+1); @@ -2229,7 +2195,7 @@ static void msb_remove(struct memstick_dev *card) msb_data_clear(msb); mutex_unlock(&msb_disk_lock); - msb_disk_release(msb->disk); + put_disk(msb->disk); memstick_set_drvdata(card, NULL); } diff --git a/drivers/memstick/core/ms_block.h b/drivers/memstick/core/ms_block.h index 122e1a8a8bd5b..7058f9aefeb92 100644 --- a/drivers/memstick/core/ms_block.h +++ b/drivers/memstick/core/ms_block.h @@ -143,7 +143,6 @@ struct ms_boot_page { } __packed; struct msb_data { - unsigned int usage_count; struct memstick_dev *card; struct gendisk *disk; struct request_queue *queue; From patchwork Wed Feb 9 08:21:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541647 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 629E7C433EF for ; Wed, 9 Feb 2022 08:21:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240914AbiBIIVf (ORCPT ); Wed, 9 Feb 2022 03:21:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232023AbiBIIVe (ORCPT ); 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Wed, 09 Feb 2022 08:21:33 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 3/5] memstick/mspro_block: fix handling of read-only devices Date: Wed, 9 Feb 2022 09:21:18 +0100 Message-Id: <20220209082121.2628452-4-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Use set_disk_ro to propagate the read-only state to the block layer instead of checking for it in ->open and leaking a reference in case of a read-only device. Signed-off-by: Christoph Hellwig --- drivers/memstick/core/mspro_block.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/memstick/core/mspro_block.c b/drivers/memstick/core/mspro_block.c index c0450397b6735..7ea312f0840e0 100644 --- a/drivers/memstick/core/mspro_block.c +++ b/drivers/memstick/core/mspro_block.c @@ -186,13 +186,8 @@ static int mspro_block_bd_open(struct block_device *bdev, fmode_t mode) mutex_lock(&mspro_block_disk_lock); - if (msb && msb->card) { + if (msb && msb->card) msb->usage_count++; - if ((mode & FMODE_WRITE) && msb->read_only) - rc = -EROFS; - else - rc = 0; - } mutex_unlock(&mspro_block_disk_lock); @@ -1239,6 +1234,9 @@ static int mspro_block_init_disk(struct memstick_dev *card) set_capacity(msb->disk, capacity); dev_dbg(&card->dev, "capacity set %ld\n", capacity); + if (msb->read_only) + set_disk_ro(msb->disk, true); + rc = device_add_disk(&card->dev, msb->disk, NULL); if (rc) goto out_cleanup_disk; From patchwork Wed Feb 9 08:21:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541646 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12E25C4332F for ; Wed, 9 Feb 2022 08:21:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240977AbiBIIVm (ORCPT ); Wed, 9 Feb 2022 03:21:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240921AbiBIIVj (ORCPT ); Wed, 9 Feb 2022 03:21:39 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD7AEC05CB87; Wed, 9 Feb 2022 00:21:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=HHdkFhXzph/YEDr3VFGzAg3QAN/EIa/uRvErt377FsM=; b=m90SK4+qB0m0qM/1gvmFRcpoBk 7xkl/6ZhQzPEMMhMgkW3o/YR9SPw5e2eceYuzRXjaGS3pg+GjQqpY8GFUe+SDEMOpIK1CJImXdztw VPltFGqo0r3vBV/EIJAjCVY0kfKCuJZiYrbx0DKHrMYLamfuhhVlAc6p7i/5qz2VW7iF1Ci7Znx7x 5KG8jVj1ZIrHKKz01jiR6W5REkN3ufdSbPzBb4UpQvx6tHqRL7ikHzBLEPodadD55U9W2wftu3DlS YzjO8f9EFrpkqzWEs1dA0ozYk7aUv5V3rHHbg6CM91VIwuuGFCE8bh9evedF9XStVxb+mvH16B/Lr kQ/jSH3w==; Received: from [2001:4bb8:188:3efc:ea2:7599:7eeb:4b5a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHiEJ-00GbBn-Nu; Wed, 09 Feb 2022 08:21:36 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 4/5] memstick/mspro_block: simplify refcounting Date: Wed, 9 Feb 2022 09:21:19 +0100 Message-Id: <20220209082121.2628452-5-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Implement the ->free_disk method to free the msb_data structure only once the last gendisk reference goes away instead of keeping a local refcount. Signed-off-by: Christoph Hellwig --- drivers/memstick/core/mspro_block.c | 49 +++++------------------------ 1 file changed, 7 insertions(+), 42 deletions(-) diff --git a/drivers/memstick/core/mspro_block.c b/drivers/memstick/core/mspro_block.c index 7ea312f0840e0..725ba74ded308 100644 --- a/drivers/memstick/core/mspro_block.c +++ b/drivers/memstick/core/mspro_block.c @@ -133,7 +133,6 @@ struct mspro_devinfo { struct mspro_block_data { struct memstick_dev *card; - unsigned int usage_count; unsigned int caps; struct gendisk *disk; struct request_queue *queue; @@ -178,48 +177,16 @@ static int mspro_block_complete_req(struct memstick_dev *card, int error); /*** Block device ***/ -static int mspro_block_bd_open(struct block_device *bdev, fmode_t mode) -{ - struct gendisk *disk = bdev->bd_disk; - struct mspro_block_data *msb = disk->private_data; - int rc = -ENXIO; - - mutex_lock(&mspro_block_disk_lock); - - if (msb && msb->card) - msb->usage_count++; - - mutex_unlock(&mspro_block_disk_lock); - - return rc; -} - - -static void mspro_block_disk_release(struct gendisk *disk) +static void mspro_block_bd_free_disk(struct gendisk *disk) { struct mspro_block_data *msb = disk->private_data; int disk_id = MINOR(disk_devt(disk)) >> MSPRO_BLOCK_PART_SHIFT; mutex_lock(&mspro_block_disk_lock); - - if (msb) { - if (msb->usage_count) - msb->usage_count--; - - if (!msb->usage_count) { - kfree(msb); - disk->private_data = NULL; - idr_remove(&mspro_block_disk_idr, disk_id); - put_disk(disk); - } - } - + idr_remove(&mspro_block_disk_idr, disk_id); mutex_unlock(&mspro_block_disk_lock); -} -static void mspro_block_bd_release(struct gendisk *disk, fmode_t mode) -{ - mspro_block_disk_release(disk); + kfree(msb); } static int mspro_block_bd_getgeo(struct block_device *bdev, @@ -235,10 +202,9 @@ static int mspro_block_bd_getgeo(struct block_device *bdev, } static const struct block_device_operations ms_block_bdops = { - .open = mspro_block_bd_open, - .release = mspro_block_bd_release, - .getgeo = mspro_block_bd_getgeo, - .owner = THIS_MODULE + .owner = THIS_MODULE, + .getgeo = mspro_block_bd_getgeo, + .free_disk = mspro_block_bd_free_disk, }; /*** Information ***/ @@ -1221,7 +1187,6 @@ static int mspro_block_init_disk(struct memstick_dev *card) msb->disk->first_minor = disk_id << MSPRO_BLOCK_PART_SHIFT; msb->disk->minors = 1 << MSPRO_BLOCK_PART_SHIFT; msb->disk->fops = &ms_block_bdops; - msb->usage_count = 1; msb->disk->private_data = msb; sprintf(msb->disk->disk_name, "mspblk%d", disk_id); @@ -1339,7 +1304,7 @@ static void mspro_block_remove(struct memstick_dev *card) mspro_block_data_clear(msb); mutex_unlock(&mspro_block_disk_lock); - mspro_block_disk_release(msb->disk); + put_disk(msb->disk); memstick_set_drvdata(card, NULL); } From patchwork Wed Feb 9 08:21:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 541312 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 997E0C433FE for ; Wed, 9 Feb 2022 08:21:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241081AbiBIIVs (ORCPT ); Wed, 9 Feb 2022 03:21:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241009AbiBIIVo (ORCPT ); Wed, 9 Feb 2022 03:21:44 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0617C05CB8C; Wed, 9 Feb 2022 00:21:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=F2lIZdBncpE9NDo/cYhvW0BcY5k8p1Xy0zkeny0OuCE=; b=pm8/6EA1MklZpU91ac7ttgR1yv iAfCmchEDh+O3/gwYXKpLpPMsl2q/V6G+Df+WJKA72rIpcKNiR7t4M3DBX99tiPC1A94F/OQAIzfj ii6UisZBqnzWVLpgzoxAKknFdJEbj03W3INLbruwZ6VCzLlUElFxG05UNQy4Ys2ycsStkDggzrlku /nFPUvV86l1axSa4JUkZ3yh/GKtKF5UXVjk4KEI8gIGzK0efZ7z6zg/Pmv8QRUYSWNekmU02F5mp1 K77f4vMG0I8emFqrR+tkvwQLzn12m7XsvUCYeOVEbzld+txku58ng5tOj5TOwlV10qa8uiAzUIvZ9 dHhpmhhQ==; Received: from [2001:4bb8:188:3efc:ea2:7599:7eeb:4b5a] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHiEM-00GbCA-Cj; Wed, 09 Feb 2022 08:21:38 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Maxim Levitsky , Alex Dubov , Ulf Hansson , linux-block@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mmc@vger.kernel.org Subject: [PATCH 5/5] virtio_blk: simplify refcounting Date: Wed, 9 Feb 2022 09:21:20 +0100 Message-Id: <20220209082121.2628452-6-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209082121.2628452-1-hch@lst.de> References: <20220209082121.2628452-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Implement the ->free_disk method to free the virtio_blk structure only once the last gendisk reference goes away instead of keeping a local refcount. Signed-off-by: Christoph Hellwig Acked-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi --- drivers/block/virtio_blk.c | 74 +++++++++++--------------------------- 1 file changed, 21 insertions(+), 53 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c443cd64fc9b4..05cc5451d6cc1 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -69,13 +69,6 @@ struct virtio_blk { /* Process context for config space updates */ struct work_struct config_work; - /* - * Tracks references from block_device_operations open/release and - * virtio_driver probe/remove so this object can be freed once no - * longer in use. - */ - refcount_t refs; - /* What host tells us, plus 2 for header & tailer. */ unsigned int sg_elems; @@ -391,43 +384,6 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str) return err; } -static void virtblk_get(struct virtio_blk *vblk) -{ - refcount_inc(&vblk->refs); -} - -static void virtblk_put(struct virtio_blk *vblk) -{ - if (refcount_dec_and_test(&vblk->refs)) { - ida_simple_remove(&vd_index_ida, vblk->index); - mutex_destroy(&vblk->vdev_mutex); - kfree(vblk); - } -} - -static int virtblk_open(struct block_device *bd, fmode_t mode) -{ - struct virtio_blk *vblk = bd->bd_disk->private_data; - int ret = 0; - - mutex_lock(&vblk->vdev_mutex); - - if (vblk->vdev) - virtblk_get(vblk); - else - ret = -ENXIO; - - mutex_unlock(&vblk->vdev_mutex); - return ret; -} - -static void virtblk_release(struct gendisk *disk, fmode_t mode) -{ - struct virtio_blk *vblk = disk->private_data; - - virtblk_put(vblk); -} - /* We provide getgeo only to please some old bootloader/partitioning tools */ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) { @@ -460,11 +416,19 @@ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) return ret; } +static void virtblk_free_disk(struct gendisk *disk) +{ + struct virtio_blk *vblk = disk->private_data; + + ida_simple_remove(&vd_index_ida, vblk->index); + mutex_destroy(&vblk->vdev_mutex); + kfree(vblk); +} + static const struct block_device_operations virtblk_fops = { - .owner = THIS_MODULE, - .open = virtblk_open, - .release = virtblk_release, - .getgeo = virtblk_getgeo, + .owner = THIS_MODULE, + .getgeo = virtblk_getgeo, + .free_disk = virtblk_free_disk, }; static int index_to_minor(int index) @@ -791,8 +755,6 @@ static int virtblk_probe(struct virtio_device *vdev) goto out_free_index; } - /* This reference is dropped in virtblk_remove(). */ - refcount_set(&vblk->refs, 1); mutex_init(&vblk->vdev_mutex); vblk->vdev = vdev; @@ -948,7 +910,13 @@ static int virtblk_probe(struct virtio_device *vdev) return 0; out_cleanup_disk: - blk_cleanup_disk(vblk->disk); + blk_cleanup_queue(vblk->disk->queue); + blk_mq_free_tag_set(&vblk->tag_set); + vdev->config->del_vqs(vdev); + kfree(vblk->vqs); + put_disk(vblk->disk); + return err; + out_free_tags: blk_mq_free_tag_set(&vblk->tag_set); out_free_vq: @@ -970,7 +938,7 @@ static void virtblk_remove(struct virtio_device *vdev) flush_work(&vblk->config_work); del_gendisk(vblk->disk); - blk_cleanup_disk(vblk->disk); + blk_cleanup_queue(vblk->disk->queue); blk_mq_free_tag_set(&vblk->tag_set); mutex_lock(&vblk->vdev_mutex); @@ -986,7 +954,7 @@ static void virtblk_remove(struct virtio_device *vdev) mutex_unlock(&vblk->vdev_mutex); - virtblk_put(vblk); + put_disk(vblk->disk); } #ifdef CONFIG_PM_SLEEP