Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754421AbaLVLtt (ORCPT ); Mon, 22 Dec 2014 06:49:49 -0500 Received: from mail-wg0-f51.google.com ([74.125.82.51]:58567 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754602AbaLVLtq (ORCPT ); Mon, 22 Dec 2014 06:49:46 -0500 From: Dongsu Park To: linux-kernel@vger.kernel.org Cc: Jens Axboe , Kent Overstreet , Ming Lin , Dongsu Park Subject: [RFC PATCH 03/17] block: simplify issueing discard, write_same, zeroout Date: Mon, 22 Dec 2014 12:48:30 +0100 Message-Id: X-Mailer: git-send-email 2.1.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kent Overstreet Simplify special cases for issueing discard, write_same, and zeroout, replacing bio_batch completions with submit_bio_wait(). This conversion is possible because generic_make_request() will now do for us what the code in blk-lib.c was doing manually, with the bio_batch stuff. So we still need some looping in case we're trying to discard/zeroout more than around a gigabyte, but when we can submit that much at a time doing the submissions in parallel really shouldn't matter. Signed-off-by: Kent Overstreet [dpark: add more description in commit message] Signed-off-by: Dongsu Park Cc: Jens Axboe --- block/blk-lib.c | 173 ++++++++++---------------------------------------------- 1 file changed, 29 insertions(+), 144 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index 8411be3..deef044 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -9,23 +9,6 @@ #include "blk.h" -struct bio_batch { - atomic_t done; - unsigned long flags; - struct completion *wait; -}; - -static void bio_batch_end_io(struct bio *bio, int err) -{ - struct bio_batch *bb = bio->bi_private; - - if (err && (err != -EOPNOTSUPP)) - clear_bit(BIO_UPTODATE, &bb->flags); - if (atomic_dec_and_test(&bb->done)) - complete(bb->wait); - bio_put(bio); -} - /** * blkdev_issue_discard - queue a discard * @bdev: blockdev to issue discard for @@ -40,15 +23,10 @@ static void bio_batch_end_io(struct bio *bio, int err) int blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, unsigned long flags) { - DECLARE_COMPLETION_ONSTACK(wait); struct request_queue *q = bdev_get_queue(bdev); int type = REQ_WRITE | REQ_DISCARD; - unsigned int max_discard_sectors, granularity; - int alignment; - struct bio_batch bb; struct bio *bio; int ret = 0; - struct blk_plug plug; if (!q) return -ENXIO; @@ -56,69 +34,27 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, if (!blk_queue_discard(q)) return -EOPNOTSUPP; - /* Zero-sector (unknown) and one-sector granularities are the same. */ - granularity = max(q->limits.discard_granularity >> 9, 1U); - alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; - - /* - * Ensure that max_discard_sectors is of the proper - * granularity, so that requests stay aligned after a split. - */ - max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); - max_discard_sectors -= max_discard_sectors % granularity; - if (unlikely(!max_discard_sectors)) { - /* Avoid infinite loop below. Being cautious never hurts. */ - return -EOPNOTSUPP; - } - if (flags & BLKDEV_DISCARD_SECURE) { if (!blk_queue_secdiscard(q)) return -EOPNOTSUPP; type |= REQ_SECURE; } - atomic_set(&bb.done, 1); - bb.flags = 1 << BIO_UPTODATE; - bb.wait = &wait; - - blk_start_plug(&plug); while (nr_sects) { - unsigned int req_sects; - sector_t end_sect, tmp; - bio = bio_alloc(gfp_mask, 1); - if (!bio) { - ret = -ENOMEM; - break; - } - - req_sects = min_t(sector_t, nr_sects, max_discard_sectors); + if (!bio) + return -ENOMEM; - /* - * If splitting a request, and the next starting sector would be - * misaligned, stop the discard at the previous aligned sector. - */ - end_sect = sector + req_sects; - tmp = end_sect; - if (req_sects < nr_sects && - sector_div(tmp, granularity) != alignment) { - end_sect = end_sect - alignment; - sector_div(end_sect, granularity); - end_sect = end_sect * granularity + alignment; - req_sects = end_sect - sector; - } - - bio->bi_iter.bi_sector = sector; - bio->bi_end_io = bio_batch_end_io; bio->bi_bdev = bdev; - bio->bi_private = &bb; + bio->bi_iter.bi_sector = sector; + bio->bi_iter.bi_size = min_t(sector_t, nr_sects, 1 << 20) << 9; - bio->bi_iter.bi_size = req_sects << 9; - nr_sects -= req_sects; - sector = end_sect; + sector += bio_sectors(bio); + nr_sects -= bio_sectors(bio); - atomic_inc(&bb.done); - submit_bio(type, bio); + ret = submit_bio_wait(type, bio); + if (ret) + break; /* * We can loop for a long time in here, if someone does @@ -128,14 +64,6 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, */ cond_resched(); } - blk_finish_plug(&plug); - - /* Wait for bios in-flight */ - if (!atomic_dec_and_test(&bb.done)) - wait_for_completion_io(&wait); - - if (!test_bit(BIO_UPTODATE, &bb.flags)) - ret = -EIO; return ret; } @@ -156,61 +84,37 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct page *page) { - DECLARE_COMPLETION_ONSTACK(wait); struct request_queue *q = bdev_get_queue(bdev); - unsigned int max_write_same_sectors; - struct bio_batch bb; struct bio *bio; int ret = 0; if (!q) return -ENXIO; - max_write_same_sectors = q->limits.max_write_same_sectors; - - if (max_write_same_sectors == 0) + if (!q->limits.max_write_same_sectors) return -EOPNOTSUPP; - atomic_set(&bb.done, 1); - bb.flags = 1 << BIO_UPTODATE; - bb.wait = &wait; - while (nr_sects) { bio = bio_alloc(gfp_mask, 1); - if (!bio) { - ret = -ENOMEM; - break; - } + if (!bio) + return -ENOMEM; - bio->bi_iter.bi_sector = sector; - bio->bi_end_io = bio_batch_end_io; bio->bi_bdev = bdev; - bio->bi_private = &bb; + bio->bi_iter.bi_sector = sector; + bio->bi_iter.bi_size = min_t(sector_t, nr_sects, 1 << 20) << 9; bio->bi_vcnt = 1; bio->bi_io_vec->bv_page = page; bio->bi_io_vec->bv_offset = 0; bio->bi_io_vec->bv_len = bdev_logical_block_size(bdev); - if (nr_sects > max_write_same_sectors) { - bio->bi_iter.bi_size = max_write_same_sectors << 9; - nr_sects -= max_write_same_sectors; - sector += max_write_same_sectors; - } else { - bio->bi_iter.bi_size = nr_sects << 9; - nr_sects = 0; - } + sector += bio_sectors(bio); + nr_sects -= bio_sectors(bio); - atomic_inc(&bb.done); - submit_bio(REQ_WRITE | REQ_WRITE_SAME, bio); + ret = submit_bio_wait(REQ_WRITE | REQ_WRITE_SAME, bio); + if (ret) + break; } - /* Wait for bios in-flight */ - if (!atomic_dec_and_test(&bb.done)) - wait_for_completion_io(&wait); - - if (!test_bit(BIO_UPTODATE, &bb.flags)) - ret = -ENOTSUPP; - return ret; } EXPORT_SYMBOL(blkdev_issue_write_same); @@ -225,33 +129,22 @@ EXPORT_SYMBOL(blkdev_issue_write_same); * Description: * Generate and issue number of bios with zerofiled pages. */ - static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask) { - int ret; + int ret = 0; struct bio *bio; - struct bio_batch bb; unsigned int sz; - DECLARE_COMPLETION_ONSTACK(wait); - - atomic_set(&bb.done, 1); - bb.flags = 1 << BIO_UPTODATE; - bb.wait = &wait; - ret = 0; - while (nr_sects != 0) { + while (nr_sects) { bio = bio_alloc(gfp_mask, - min(nr_sects, (sector_t)BIO_MAX_PAGES)); - if (!bio) { - ret = -ENOMEM; - break; - } + min(nr_sects / (PAGE_SIZE >> 9), + (sector_t)BIO_MAX_PAGES)); + if (!bio) + return -ENOMEM; bio->bi_iter.bi_sector = sector; bio->bi_bdev = bdev; - bio->bi_end_io = bio_batch_end_io; - bio->bi_private = &bb; while (nr_sects != 0) { sz = min((sector_t) PAGE_SIZE >> 9 , nr_sects); @@ -261,18 +154,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, if (ret < (sz << 9)) break; } - ret = 0; - atomic_inc(&bb.done); - submit_bio(WRITE, bio); - } - - /* Wait for bios in-flight */ - if (!atomic_dec_and_test(&bb.done)) - wait_for_completion_io(&wait); - if (!test_bit(BIO_UPTODATE, &bb.flags)) - /* One of bios in the batch was completed with error.*/ - ret = -EIO; + ret = submit_bio_wait(WRITE, bio); + if (ret) + break; + } return ret; } @@ -287,7 +173,6 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, * Description: * Generate and issue number of bios with zerofiled pages. */ - int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask) { -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/