From patchwork Thu Jan 16 12:36:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirill Tkhai X-Patchwork-Id: 11336661 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BCACC139A for ; Thu, 16 Jan 2020 12:36:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 914B6208C3 for ; Thu, 16 Jan 2020 12:36:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726574AbgAPMgk (ORCPT ); Thu, 16 Jan 2020 07:36:40 -0500 Received: from relay.sw.ru ([185.231.240.75]:39064 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726082AbgAPMgj (ORCPT ); Thu, 16 Jan 2020 07:36:39 -0500 Received: from dhcp-172-16-24-104.sw.ru ([172.16.24.104] helo=localhost.localdomain) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1is4NX-0000yX-D5; Thu, 16 Jan 2020 15:36:03 +0300 Subject: [PATCH block v2 2/3] block: Add support for REQ_NOZERO flag From: Kirill Tkhai To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, martin.petersen@oracle.com, axboe@kernel.dk, tytso@mit.edu, adilger.kernel@dilger.ca, Chaitanya.Kulkarni@wdc.com, darrick.wong@oracle.com, ming.lei@redhat.com, osandov@fb.com, jthumshirn@suse.de, minwoo.im.dev@gmail.com, damien.lemoal@wdc.com, andrea.parri@amarulasolutions.com, hare@suse.com, tj@kernel.org, ajay.joshi@wdc.com, sagi@grimberg.me, dsterba@suse.com, chaitanya.kulkarni@wdc.com, bvanassche@acm.org, dhowells@redhat.com, asml.silence@gmail.com, ktkhai@virtuozzo.com Date: Thu, 16 Jan 2020 15:36:03 +0300 Message-ID: <157917816325.88675.16481772163916741596.stgit@localhost.localdomain> In-Reply-To: <157917805422.88675.6477661554332322975.stgit@localhost.localdomain> References: <157917805422.88675.6477661554332322975.stgit@localhost.localdomain> User-Agent: StGit/0.19 MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This adds support for REQ_NOZERO extension of REQ_OP_WRITE_ZEROES operation, which encourages a block device driver to just allocate blocks (or mark them allocated) instead of actual blocks zeroing. REQ_NOZERO is aimed to be used for network filesystems providing a block device interface. Also, block devices, which map a file on other filesystem (like loop), may use this for less fragmentation and batching fallocate() requests. Hypervisors like QEMU may introduce optimizations of clusters allocations based on this. BLKDEV_ZERO_ALLOCATE is a new corresponding flag for blkdev_issue_zeroout(). CC: Martin K. Petersen Signed-off-by: Kirill Tkhai --- block/blk-core.c | 6 +++--- block/blk-lib.c | 17 ++++++++++------- block/blk-merge.c | 9 ++++++--- block/blk-settings.c | 17 +++++++++++++++++ fs/block_dev.c | 4 ++++ include/linux/blk_types.h | 5 ++++- include/linux/blkdev.h | 31 ++++++++++++++++++++++++------- 7 files changed, 68 insertions(+), 21 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 50a5de025d5e..2edcd55624f1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -978,7 +978,7 @@ generic_make_request_checks(struct bio *bio) goto not_supported; break; case REQ_OP_WRITE_ZEROES: - if (!q->limits.max_write_zeroes_sectors) + if (!blk_queue_get_max_write_zeroes_sectors(q, bio->bi_opf)) goto not_supported; break; default: @@ -1250,10 +1250,10 @@ EXPORT_SYMBOL(submit_bio); static int blk_cloned_rq_check_limits(struct request_queue *q, struct request *rq) { - if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) { + if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, rq->cmd_flags)) { printk(KERN_ERR "%s: over max size limit. (%u > %u)\n", __func__, blk_rq_sectors(rq), - blk_queue_get_max_sectors(q, req_op(rq))); + blk_queue_get_max_sectors(q, rq->cmd_flags)); return -EIO; } diff --git a/block/blk-lib.c b/block/blk-lib.c index 3e38c93cfc53..3e80279eb029 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -214,7 +214,7 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, struct bio **biop, unsigned flags) { struct bio *bio = *biop; - unsigned int max_write_zeroes_sectors; + unsigned int max_write_zeroes_sectors, req_flags = 0; struct request_queue *q = bdev_get_queue(bdev); if (!q) @@ -224,18 +224,21 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, return -EPERM; /* Ensure that max_write_zeroes_sectors doesn't overflow bi_size */ - max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev, 0); + max_write_zeroes_sectors = bdev_write_zeroes_sectors(bdev, flags); if (max_write_zeroes_sectors == 0) return -EOPNOTSUPP; + if (flags & BLKDEV_ZERO_NOUNMAP) + req_flags |= REQ_NOUNMAP; + if (flags & BLKDEV_ZERO_ALLOCATE) + req_flags |= REQ_NOZERO|REQ_NOUNMAP; + while (nr_sects) { bio = blk_next_bio(bio, 0, gfp_mask); bio->bi_iter.bi_sector = sector; bio_set_dev(bio, bdev); - bio->bi_opf = REQ_OP_WRITE_ZEROES; - if (flags & BLKDEV_ZERO_NOUNMAP) - bio->bi_opf |= REQ_NOUNMAP; + bio->bi_opf = REQ_OP_WRITE_ZEROES | req_flags; if (nr_sects > max_write_zeroes_sectors) { bio->bi_iter.bi_size = max_write_zeroes_sectors << 9; @@ -362,7 +365,7 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t bs_mask; struct bio *bio; struct blk_plug plug; - bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev, 0); + bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev, flags); bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1; if ((sector | nr_sects) & bs_mask) @@ -391,7 +394,7 @@ int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, try_write_zeroes = false; goto retry; } - if (!bdev_write_zeroes_sectors(bdev, 0)) { + if (!bdev_write_zeroes_sectors(bdev, flags)) { /* * Zeroing offload support was indicated, but the * device reported ILLEGAL REQUEST (for some devices diff --git a/block/blk-merge.c b/block/blk-merge.c index 347782a24a35..e3ce4b87bbaa 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -105,15 +105,18 @@ static struct bio *blk_bio_discard_split(struct request_queue *q, static struct bio *blk_bio_write_zeroes_split(struct request_queue *q, struct bio *bio, struct bio_set *bs, unsigned *nsegs) { + unsigned int max_sectors; + + max_sectors = blk_queue_get_max_write_zeroes_sectors(q, bio->bi_opf); *nsegs = 0; - if (!q->limits.max_write_zeroes_sectors) + if (!max_sectors) return NULL; - if (bio_sectors(bio) <= q->limits.max_write_zeroes_sectors) + if (bio_sectors(bio) <= max_sectors) return NULL; - return bio_split(bio, q->limits.max_write_zeroes_sectors, GFP_NOIO, bs); + return bio_split(bio, max_sectors, GFP_NOIO, bs); } static struct bio *blk_bio_write_same_split(struct request_queue *q, diff --git a/block/blk-settings.c b/block/blk-settings.c index 5f6dcc7a47bd..f682374c5106 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -48,6 +48,7 @@ void blk_set_default_limits(struct queue_limits *lim) lim->chunk_sectors = 0; lim->max_write_same_sectors = 0; lim->max_write_zeroes_sectors = 0; + lim->max_allocate_sectors = 0; lim->max_discard_sectors = 0; lim->max_hw_discard_sectors = 0; lim->discard_granularity = 0; @@ -83,6 +84,7 @@ void blk_set_stacking_limits(struct queue_limits *lim) lim->max_dev_sectors = UINT_MAX; lim->max_write_same_sectors = UINT_MAX; lim->max_write_zeroes_sectors = UINT_MAX; + lim->max_allocate_sectors = UINT_MAX; } EXPORT_SYMBOL(blk_set_stacking_limits); @@ -257,6 +259,19 @@ void blk_queue_max_write_zeroes_sectors(struct request_queue *q, } EXPORT_SYMBOL(blk_queue_max_write_zeroes_sectors); +/** + * blk_queue_max_allocate_sectors - set max sectors for a single + * allocate request + * @q: the request queue for the device + * @max_allocate_sectors: maximum number of sectors to write per command + **/ +void blk_queue_max_allocate_sectors(struct request_queue *q, + unsigned int max_allocate_sectors) +{ + q->limits.max_allocate_sectors = max_allocate_sectors; +} +EXPORT_SYMBOL(blk_queue_max_allocate_sectors); + /** * blk_queue_max_segments - set max hw segments for a request for this queue * @q: the request queue for the device @@ -506,6 +521,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, b->max_write_same_sectors); t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors, b->max_write_zeroes_sectors); + t->max_allocate_sectors = min(t->max_allocate_sectors, + b->max_allocate_sectors); t->bounce_pfn = min_not_zero(t->bounce_pfn, b->bounce_pfn); t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, diff --git a/fs/block_dev.c b/fs/block_dev.c index 69bf2fb6f7cd..1ffef894b3bd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -2122,6 +2122,10 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); break; + case FALLOC_FL_KEEP_SIZE: + error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, + GFP_KERNEL, BLKDEV_ZERO_ALLOCATE | BLKDEV_ZERO_NOFALLBACK); + break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: error = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 70254ae11769..9ed166860099 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -335,7 +335,9 @@ enum req_flag_bits { /* command specific flags for REQ_OP_WRITE_ZEROES: */ __REQ_NOUNMAP, /* do not free blocks when zeroing */ - + __REQ_NOZERO, /* only notify about allocated blocks, + * and do not actual zero them + */ __REQ_HIPRI, /* for driver use */ @@ -362,6 +364,7 @@ enum req_flag_bits { #define REQ_CGROUP_PUNT (1ULL << __REQ_CGROUP_PUNT) #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) +#define REQ_NOZERO (1ULL << __REQ_NOZERO) #define REQ_HIPRI (1ULL << __REQ_HIPRI) #define REQ_DRV (1ULL << __REQ_DRV) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4cd69552df9a..f4ec5db64432 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -336,6 +336,7 @@ struct queue_limits { unsigned int max_hw_discard_sectors; unsigned int max_write_same_sectors; unsigned int max_write_zeroes_sectors; + unsigned int max_allocate_sectors; unsigned int discard_granularity; unsigned int discard_alignment; @@ -988,9 +989,19 @@ static inline struct bio_vec req_bvec(struct request *rq) return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter); } +static inline unsigned int blk_queue_get_max_write_zeroes_sectors( + struct request_queue *q, unsigned int op_flags) +{ + if (op_flags & REQ_NOZERO) + return q->limits.max_allocate_sectors; + return q->limits.max_write_zeroes_sectors; +} + static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, - int op) + unsigned int op_flags) { + int op = op_flags & REQ_OP_MASK; + if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE)) return min(q->limits.max_discard_sectors, UINT_MAX >> SECTOR_SHIFT); @@ -999,7 +1010,7 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, return q->limits.max_write_same_sectors; if (unlikely(op == REQ_OP_WRITE_ZEROES)) - return q->limits.max_write_zeroes_sectors; + return blk_queue_get_max_write_zeroes_sectors(q, op_flags); return q->limits.max_sectors; } @@ -1029,10 +1040,10 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq, if (!q->limits.chunk_sectors || req_op(rq) == REQ_OP_DISCARD || req_op(rq) == REQ_OP_SECURE_ERASE) - return blk_queue_get_max_sectors(q, req_op(rq)); + return blk_queue_get_max_sectors(q, rq->cmd_flags); return min(blk_max_size_offset(q, offset), - blk_queue_get_max_sectors(q, req_op(rq))); + blk_queue_get_max_sectors(q, rq->cmd_flags)); } static inline unsigned int blk_rq_count_bios(struct request *rq) @@ -1078,6 +1089,8 @@ extern void blk_queue_max_write_same_sectors(struct request_queue *q, unsigned int max_write_same_sectors); extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q, unsigned int max_write_same_sectors); +extern void blk_queue_max_allocate_sectors(struct request_queue *q, + unsigned int max_allocate_sectors); extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); extern void blk_queue_alignment_offset(struct request_queue *q, @@ -1219,6 +1232,7 @@ extern int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, #define BLKDEV_ZERO_NOUNMAP (1 << 0) /* do not free blocks */ #define BLKDEV_ZERO_NOFALLBACK (1 << 1) /* don't write explicit zeroes */ +#define BLKDEV_ZERO_ALLOCATE (1 << 2) /* allocate range of blocks */ extern int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, @@ -1423,10 +1437,13 @@ static inline unsigned int bdev_write_zeroes_sectors(struct block_device *bdev, { struct request_queue *q = bdev_get_queue(bdev); - if (q) - return q->limits.max_write_zeroes_sectors; + if (!q) + return 0; - return 0; + if (flags & BLKDEV_ZERO_ALLOCATE) + return q->limits.max_allocate_sectors; + else + return q->limits.max_write_zeroes_sectors; } static inline enum blk_zoned_model bdev_zoned_model(struct block_device *bdev)