From patchwork Tue Mar 12 14:45:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13590117 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA2911DFD8; Tue, 12 Mar 2024 14:45:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254744; cv=none; b=hE9dMQjTR5ft4DWsCQMHDXeKBPBcQQp6NMSn1r9NXm5XmQYfQuxSn2nahm7p2DXW6GZ1xmbFzp5RpGaFGDA+1hqowx/5tSaxWn/N2NzzB9NFMBlVF8Zlvkt2A5GKP77y5uLffJ4fRhYQRmpokw68mXmDNELeZFOI86EN1cRwLlA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254744; c=relaxed/simple; bh=Ls2beDqT1fpA9RDS0rEL8fsnufcoewqU2agFzA3pmos=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=l4IqdjrIjbvIKSaEjRmetwyUoaFIc52kz0DaN4yMqGXNqepGShKyvIstv1T6OJrew7cEduVo7WjMlce0SHyeRwZxwW552551cuVTYk2Bj9fY78mcC+SoSEFRZppU3t7gDEKO/3/+SjExOljFdApkFeyv6L3n4ULPuZkTS5y8NYk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=MCCj4xt2; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="MCCj4xt2" 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=vSsMfJD3f2N5FqYGaSXx227O7Ol0Kb1Bq+IO61l8gLU=; b=MCCj4xt2AAzGYF6yq4+ayaTTSi zVx2XNkBIH+5HGywq+W/UbXBFjbnm5PkTRK0DGMqVFnirgRB1BIj01AQveVPAi5P4+lUC1AOdJoGS mRnX7cOM1LqEFddgaj2Af4X5IVcUifZQNQMtehgeZTt/RbL3ksZXuC5tA+827tX6v9nhAyvnxKH0D SrAwODNBsbS32sw16w07NxalqiAE8UMCWA7eHZVtXyq0XTpR/g+nO8J2EADArgwsG6ldqT71pPzGJ 0wNHaRcFlrP/D7cle6wcgLCaohrZwaeDto0GCcmNmkrRi94wT57AmYjizb4P+HI1YXLhfDlPwhkOA tpPgTImg==; Received: from [50.226.187.238] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rk3Nt-00000006C72-3B5Z; Tue, 12 Mar 2024 14:45:42 +0000 From: Christoph Hellwig To: Jens Axboe , Chandan Babu R , Keith Busch Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org Subject: [PATCH 1/5] block: move discard checks into the ioctl handler Date: Tue, 12 Mar 2024 08:45:27 -0600 Message-Id: <20240312144532.1044427-2-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240312144532.1044427-1-hch@lst.de> References: <20240312144532.1044427-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Most bio operations get basic sanity checking in submit_bio and anything more complicated than that is done in the callers. Discards are a bit different from that in that a lot of checking is done in __blkdev_issue_discard, and the specific errnos for that are returned to userspace. Move the checks that require specific errnos to the ioctl handler instead and replace the existing kernel sector alignment check with the actual alignment check based on the logical block size. This leaves jut the basic sanity checking in submit_bio for the other submitters of discards and introduces two changes in behavior: 1) the logical block size alignment check of the start and len is lost for non-ioctl callers. This matches what is done for other operations including reads and writes. We should probably verify this for all bios, but for now make discards match the normal flow. 2) for non-ioctl callers all errors are reported on I/O completion now instead of synchronously. Callers in general mostly ignore or log errors so this will actually simplify the code once cleaned up Signed-off-by: Christoph Hellwig --- block/blk-lib.c | 20 -------------------- block/ioctl.c | 13 +++++++++---- 2 files changed, 9 insertions(+), 24 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index dc8e35d0a51d6d..50923508a32466 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -59,26 +59,6 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop) { struct bio *bio = *biop; - sector_t bs_mask; - - if (bdev_read_only(bdev)) - return -EPERM; - if (!bdev_max_discard_sectors(bdev)) - return -EOPNOTSUPP; - - /* In case the discard granularity isn't set by buggy device driver */ - if (WARN_ON_ONCE(!bdev_discard_granularity(bdev))) { - pr_err_ratelimited("%pg: Error: discard_granularity is 0.\n", - bdev); - return -EOPNOTSUPP; - } - - bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; - if ((sector | nr_sects) & bs_mask) - return -EINVAL; - - if (!nr_sects) - return -EINVAL; while (nr_sects) { sector_t req_sects = diff --git a/block/ioctl.c b/block/ioctl.c index 0c76137adcaaa5..57c8171fda93c5 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -95,6 +95,8 @@ static int compat_blkpg_ioctl(struct block_device *bdev, static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, unsigned long arg) { + sector_t bs_mask = (bdev_logical_block_size(bdev) >> SECTOR_SHIFT) - 1; + sector_t sector, nr_sects; uint64_t range[2]; uint64_t start, len; struct inode *inode = bdev->bd_inode; @@ -105,18 +107,21 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, if (!bdev_max_discard_sectors(bdev)) return -EOPNOTSUPP; + if (bdev_read_only(bdev)) + return -EPERM; if (copy_from_user(range, (void __user *)arg, sizeof(range))) return -EFAULT; start = range[0]; len = range[1]; + sector = start >> SECTOR_SHIFT; + nr_sects = len >> SECTOR_SHIFT; - if (start & 511) + if (!nr_sects) return -EINVAL; - if (len & 511) + if ((sector | nr_sects) & bs_mask) return -EINVAL; - if (start + len > bdev_nr_bytes(bdev)) return -EINVAL; @@ -124,7 +129,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, err = truncate_bdev_range(bdev, mode, start, start + len - 1); if (err) goto fail; - err = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL); + err = blkdev_issue_discard(bdev, sector, nr_sects, GFP_KERNEL); fail: filemap_invalidate_unlock(inode->i_mapping); return err; From patchwork Tue Mar 12 14:45:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13590118 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 281001DFD8; Tue, 12 Mar 2024 14:45:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254747; cv=none; b=i0MbOwMsrBXbvz83b0ZxeVY59jvev4exyY9tj/NFq1Ghu8qTrjUo+Wp4yfQM4K8Zectj3WB2xhk3ss6hJi0Erj/RU/LZ2KRx+GevodOe1SF8yKIFWRMWnFZeCLYSo92dT/WnKknYpHu2MT5HZ9BM4GVRes4eYK2E9M9hgtk15oc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254747; c=relaxed/simple; bh=FFZqfCHe8EOWrtjltKtUPNRMjR8dRujOCh/4VjaeESk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LS2aNVXEhi6b0B/BvfW6I9NErsHkPbegRPFeiAOMfiBcqSOR0JGM9shDmvRoq1PUcwxrhOV63fjTFJQB+MyExYF0iSeE2IF7O6Pc2z73Q5Fli6h4c0UrZ5e1of52MA6VtOASAQno+96U8ji5ZFDb6mkV+EYRTjnYdMh6n+Aa+NU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=pjnbnW0Z; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pjnbnW0Z" 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=VjiNJMj6lv6xSOzWYTzvr2i2M7boMMC6hKAnN+ZZj6M=; b=pjnbnW0Zm1NjkZEhNvJ75+bSnj kHwSVnXJYSqsHXDVuyJilRI9C4p9ctpX/wfgzud9a5M9T7girx5yZd51/u8sagijFQaA/hSr8fIme pvGQYomzRFqpeTUlhsMFsIksGyk0ooiZymFNcil1vwNRDL27pkI6UKdQBWduc+8xOXt0cpolVb81s da9ryqwoLpTFbG9ajwGbWNL82+B1av/T4GN0+0017gSUfW1gUpL3rB9KrZ9uhLW+pSVdFXnJzv9qx fy83P2bPZdzivNJLQOYkauU2acQgVTJXMd6Z28wWVGlI29rUar7ekxanfQYoBE+416fjHip3yKC0v ByW4HR2Q==; Received: from [50.226.187.238] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rk3Nw-00000006C7z-19Kq; Tue, 12 Mar 2024 14:45:44 +0000 From: Christoph Hellwig To: Jens Axboe , Chandan Babu R , Keith Busch Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org Subject: [PATCH 2/5] block: add a bio_chain_and_submit helper Date: Tue, 12 Mar 2024 08:45:28 -0600 Message-Id: <20240312144532.1044427-3-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240312144532.1044427-1-hch@lst.de> References: <20240312144532.1044427-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html This is basically blk_next_bio just with the bio allocation moved to the caller to allow for more flexible bio handling in the caller. Signed-off-by: Christoph Hellwig --- block/bio.c | 28 ++++++++++++++++++++-------- include/linux/bio.h | 1 + 2 files changed, 21 insertions(+), 8 deletions(-) diff --git a/block/bio.c b/block/bio.c index d24420ed1c4c6f..32ff538b29e564 100644 --- a/block/bio.c +++ b/block/bio.c @@ -345,18 +345,30 @@ void bio_chain(struct bio *bio, struct bio *parent) } EXPORT_SYMBOL(bio_chain); -struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev, - unsigned int nr_pages, blk_opf_t opf, gfp_t gfp) +/** + * bio_chain_and_submit - submit a bio after chaining it to another one + * @prev: bio to chain and submit + * @new: bio to chain to + * + * If @prev is non-NULL, chain it to @new and submit it. + * + * Return: @new. + */ +struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new) { - struct bio *new = bio_alloc(bdev, nr_pages, opf, gfp); - - if (bio) { - bio_chain(bio, new); - submit_bio(bio); + if (prev) { + bio_chain(prev, new); + submit_bio(prev); } - return new; } +EXPORT_SYMBOL_GPL(bio_chain_and_submit); + +struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev, + unsigned int nr_pages, blk_opf_t opf, gfp_t gfp) +{ + return bio_chain_and_submit(bio, bio_alloc(bdev, nr_pages, opf, gfp)); +} EXPORT_SYMBOL_GPL(blk_next_bio); static void bio_alloc_rescue(struct work_struct *work) diff --git a/include/linux/bio.h b/include/linux/bio.h index 875d792bffff82..643d61b7cb82f7 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -824,5 +824,6 @@ static inline void bio_clear_polled(struct bio *bio) struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev, unsigned int nr_pages, blk_opf_t opf, gfp_t gfp); +struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new); #endif /* __LINUX_BIO_H */ From patchwork Tue Mar 12 14:45:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13590119 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 778A17AE72; Tue, 12 Mar 2024 14:45:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254748; cv=none; b=q34JmhXj1fkCKDDbW10DLGVdU6KNePfhgnpgQwbhDi2OaWTYfz11Zz+s0m/GN9IX6Pb4B1o69Ws+mijgWp3rOwUb/vLKeWZge5dYprJKsvZvdTMj7oOFqZ0+s1u5lFN1Cm5HBaRYVGC1g/Te+7qItPvUvQ2Pm0/7msLLTuUApzg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710254748; c=relaxed/simple; bh=/Zv+Ufy9VDvIabahDOh3hEnN/W+K4UKzQDGq9mpwqHI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jZXR1aD1amKM/bpDbjPgJbY+j/QRyEOS7/e2pYDPUEvQnd82c1jfnoych/+gn2P4RAKPb4+WrfHZ3ghX4dcSn1IQgONKvP/+AQFz8BfoFGWvYdGB4cCA2PPUnW5K6uNpuooM2ka8jo5W2f7gclAFJGMaTHw1MX6zUqFbPkv5xUQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=n6DBj6cI; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="n6DBj6cI" 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=0Naseq0Wthv0thDdBSJ3JbI1Kt4lTFJ0xfpQrsvbeLw=; b=n6DBj6cIvlaCzVs49C5D7MAdTw yPDIeDJ8locxWfJvQzocOq7NkXowJVZ5Eiuik6ppG9NLJI7YPgffh2EtLYrExz9L4bbCq6JCA7Jfm ZMgoQpZoqyL6ExOG7ZcIozTJGVE0MXsE/9SQO6LwGlVcPj46gRogBYp49QhmXgCwTaIOhkGZKCoE4 xKo6R1Uy2/Gh09c246vl+E1bFO7awaYHJZbexMU8nH5LLWcEnlCv0oHiWGRXvxz2Aeh3oCk/k0w7c 1GLx53cdqMtmq0HHAparu1oSsz11PIrbTl2HlifjnB0s1uYoACmekRSDeiIyIbFI7tRTk/E9bu7Vo gB/Bt0cQ==; Received: from [50.226.187.238] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rk3Ny-00000006C8z-1Shx; Tue, 12 Mar 2024 14:45:46 +0000 From: Christoph Hellwig To: Jens Axboe , Chandan Babu R , Keith Busch Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org Subject: [PATCH 3/5] block: add a blk_alloc_discard_bio helper Date: Tue, 12 Mar 2024 08:45:29 -0600 Message-Id: <20240312144532.1044427-4-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240312144532.1044427-1-hch@lst.de> References: <20240312144532.1044427-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Factor out a helper from __blkdev_issue_discard that chews off as much as possible from a discard range and allocates a bio for it. Signed-off-by: Christoph Hellwig --- block/blk-lib.c | 58 ++++++++++++++++++++++++++------------------- include/linux/bio.h | 3 +++ 2 files changed, 37 insertions(+), 24 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 50923508a32466..fd97f4dd34e7f4 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -55,36 +55,46 @@ static void await_bio_chain(struct bio *bio) blk_wait_io(&done); } +struct bio *blk_alloc_discard_bio(struct block_device *bdev, + sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask) +{ + sector_t bio_sects = min(*nr_sects, bio_discard_limit(bdev, *sector)); + struct bio *bio; + + if (WARN_ON_ONCE(!(gfp_mask & __GFP_RECLAIM))) + return NULL; + if (!bio_sects) + return NULL; + + bio = bio_alloc(bdev, 0, REQ_OP_DISCARD, gfp_mask); + bio->bi_iter.bi_sector = *sector; + bio->bi_iter.bi_size = bio_sects << SECTOR_SHIFT; + *sector += bio_sects; + *nr_sects -= bio_sects; + /* + * We can loop for a long time in here if someone does full device + * discards (like mkfs). Be nice and allow us to schedule out to avoid + * softlocking if preempt is disabled. + */ + cond_resched(); + return bio; +} + int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop) { - struct bio *bio = *biop; - - while (nr_sects) { - sector_t req_sects = - min(nr_sects, bio_discard_limit(bdev, sector)); + struct bio *bio; - bio = blk_next_bio(bio, bdev, 0, REQ_OP_DISCARD, gfp_mask); - bio->bi_iter.bi_sector = sector; - bio->bi_iter.bi_size = req_sects << 9; - sector += req_sects; - nr_sects -= req_sects; - - /* - * We can loop for a long time in here, if someone does - * full device discards (like mkfs). Be nice and allow - * us to schedule out to avoid softlocking if preempt - * is disabled. - */ - cond_resched(); - if (fatal_signal_pending(current)) { - await_bio_chain(bio); - return -EINTR; - } + while (!fatal_signal_pending(current)) { + bio = blk_alloc_discard_bio(bdev, §or, &nr_sects, gfp_mask); + if (!bio) + return 0; + *biop = bio_chain_and_submit(*biop, bio); } - *biop = bio; - return 0; + if (*biop) + await_bio_chain(*biop); + return -EINTR; } EXPORT_SYMBOL(__blkdev_issue_discard); diff --git a/include/linux/bio.h b/include/linux/bio.h index 643d61b7cb82f7..74138c815657fd 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -826,4 +826,7 @@ struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev, unsigned int nr_pages, blk_opf_t opf, gfp_t gfp); struct bio *bio_chain_and_submit(struct bio *prev, struct bio *new); +struct bio *blk_alloc_discard_bio(struct block_device *bdev, + sector_t *sector, sector_t *nr_sects, gfp_t gfp_mask); + #endif /* __LINUX_BIO_H */