From patchwork Wed Feb 5 14:38:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 11366427 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 8832A14E3 for ; Wed, 5 Feb 2020 14:38:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D5BE2082E for ; Wed, 5 Feb 2020 14:38:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="FNLIHirT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbgBEOik (ORCPT ); Wed, 5 Feb 2020 09:38:40 -0500 Received: from esa3.hgst.iphmx.com ([216.71.153.141]:34704 "EHLO esa3.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726046AbgBEOik (ORCPT ); Wed, 5 Feb 2020 09:38:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1580913520; x=1612449520; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=r78LKIuPFXClP8VdoabapwLfWyAlGWyGirwc5oyQ1tY=; b=FNLIHirTQrRVF4/9xsmyyWYDGnptyUTWQw0fvZG+vmfNbdVvULmX8jf5 GxIFNBkjqIj1O89vSwXoQxrvESYFv7BhA+MuBrteq6uSIvO65Jsdz7ukn OXrL/2yfwSgl+5OXfLn64Z0vqtpx3TxbNmG6O5GSNjS38TpCDaZHcz4Nh Tt1IuP/cPSCe3AaSaYrXBe9QbjK9pkol7xjjfutD4Ou0YNIgDmQGgWzeQ uwSgYm3cRA8bg/NTMQJg/xBj1gq8c4GpL77pccE/B185+jX6+n4eqMTWG FJ6Sf2DBnNChhdASszVxBfZNxXdFZVSOtzUy9yvg5pekn95M//IKO6oJ1 Q==; IronPort-SDR: QjoIBITvZ7RltWbWqKk89eGnGC3BG/pfmZYmDXTcZQzbBLXb8vtfq5lxqwRd3ImsusNs05pR9b S0VeiWWQyRfSVyzwnrk2W3u7CtuFC1shhCHM8cOUdNewrTcyFCt3XMP4dkv3OqzYfcR95B5OAK xkGKSLBw5oLz0z3t4dnvhayZCo7lmTsxvr8kuGUEnipuX4SQ1KC2MW4TFQG/mpiwc6JfWwnHGj pvGzpDDR+bRYCXeOYJj4pGus4zn4ZHbRGtZaVO5iQvroxfWlA6RbGfaZ64wJ5J8Q5kDthp7oDr 7es= X-IronPort-AV: E=Sophos;i="5.70,405,1574092800"; d="scan'208";a="133512045" Received: from uls-op-cesaip01.wdc.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 05 Feb 2020 22:38:39 +0800 IronPort-SDR: R01mYdaZrCwb3WkGSKEHDsxO0/0ofqij2T/S+9gYCKIU+ftu1HTiyMsREmo19Ag2nICRRm2f49 OgYgFA9CDwFGsYrFGJLPQkJYDizFRugoY8T4OfUOqWrcIM4S19wluM592HpAzzzFuVIoqWlgnY /B0eK0y77nVgRusuO0P6LfjukYGOMbfOulnrbol/uVWdQ27U0HdoCsLbquIxs/o+JqkzYl0Ygw 9xPq0ULb6swgJIdVdJd3WjmoAWRqxKGuwtqJ/EBmflQSKWMXoQYx+wnYBEAlmMVzvG3RudwGXo +NSeAmoX1Q1cLPJ3N9YL502k Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 06:31:40 -0800 IronPort-SDR: DrWnmFcM/usxymyuwQkpjYFgDlyMxVSbMzqlMPAajztI7Sd73VyeRUfnGvy35RXUsogsa7cwq6 7XV/gbaC1o3OVAaP5bKJr7+CUa72DY9gnRp7SO1C4c9nul8pfERDPS2SqMmpAR8DV/ONMrGx7m TpSDcKaInz2S/cABAEBzzDUTa5vPBpwN4uXxBFWY6l/ta4gyi7+uv4XxbEdeL+WCR7WOIYHxMs BqKzpr3hkN1TyRiQvcIsex5lo7ENfF5ZA8p62vClSCs1KeUgpKCyaatRvOkFWYLfL069GwSoXJ m8k= WDCIronportException: Internal Received: from unknown (HELO redsun60.ssa.fujisawa.hgst.com) ([10.149.66.36]) by uls-op-cesaip01.wdc.com with ESMTP; 05 Feb 2020 06:38:38 -0800 From: Johannes Thumshirn To: David Sterba Cc: Nikolay Borisov , Josef Bacik , "linux-btrfs @ vger . kernel . org" , Johannes Thumshirn Subject: [PATCH v4 2/5] btrfs: use BIOs instead of buffer_heads from superblock writeout Date: Wed, 5 Feb 2020 23:38:28 +0900 Message-Id: <20200205143831.13959-3-johannes.thumshirn@wdc.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200205143831.13959-1-johannes.thumshirn@wdc.com> References: <20200205143831.13959-1-johannes.thumshirn@wdc.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Similar to the superblock read path, change the write path to using BIOs and pages instead of buffer_heads. This allows us to skip over the buffer_head code, for writing the superblock to disk. This is based on a patch originally authored by Nikolay Borisov. Co-developed-by: Nikolay Borisov Signed-off-by: Nikolay Borisov Signed-off-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Reviewed-by: Josef Bacik --- Changes to v2: - Don't use bi_set_op_attrs() (David) Changes to v1: - Remove left-over buffer_head.h include (David) --- fs/btrfs/disk-io.c | 117 +++++++++++++++++++++++++++------------------ 1 file changed, 70 insertions(+), 47 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index bc14ef1aadda..f5343a35ac2f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -7,7 +7,6 @@ #include #include #include -#include #include #include #include @@ -3341,25 +3340,33 @@ int __cold open_ctree(struct super_block *sb, } ALLOW_ERROR_INJECTION(open_ctree, ERRNO); -static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate) +static void btrfs_end_super_write(struct bio *bio) { - if (uptodate) { - set_buffer_uptodate(bh); - } else { - struct btrfs_device *device = (struct btrfs_device *) - bh->b_private; - - btrfs_warn_rl_in_rcu(device->fs_info, - "lost page write due to IO error on %s", - rcu_str_deref(device->name)); - /* note, we don't set_buffer_write_io_error because we have - * our own ways of dealing with the IO errors - */ - clear_buffer_uptodate(bh); - btrfs_dev_stat_inc_and_print(device, BTRFS_DEV_STAT_WRITE_ERRS); + struct btrfs_device *device = bio->bi_private; + struct bio_vec *bvec; + struct bvec_iter_all iter_all; + struct page *page; + + bio_for_each_segment_all(bvec, bio, iter_all) { + page = bvec->bv_page; + + if (blk_status_to_errno(bio->bi_status)) { + btrfs_warn_rl_in_rcu(device->fs_info, + "lost page write due to IO error on %s", + rcu_str_deref(device->name)); + ClearPageUptodate(page); + SetPageError(page); + btrfs_dev_stat_inc_and_print(device, + BTRFS_DEV_STAT_WRITE_ERRS); + } else { + SetPageUptodate(page); + } + + put_page(page); + unlock_page(page); } - unlock_buffer(bh); - put_bh(bh); + + bio_put(bio); } int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num, @@ -3437,16 +3444,16 @@ int btrfs_read_dev_super(struct block_device *bdev, struct page **page) * the expected device size at commit time. Note that max_mirrors must be * same for write and wait phases. * - * Return number of errors when buffer head is not found or submission fails. + * Return number of errors when page is not found or submission fails. */ static int write_dev_supers(struct btrfs_device *device, struct btrfs_super_block *sb, int max_mirrors) { struct btrfs_fs_info *fs_info = device->fs_info; + struct address_space *mapping = device->bdev->bd_inode->i_mapping; SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); - struct buffer_head *bh; + gfp_t gfp_mask; int i; - int ret; int errors = 0; u64 bytenr; int op_flags; @@ -3456,7 +3463,13 @@ static int write_dev_supers(struct btrfs_device *device, shash->tfm = fs_info->csum_shash; + gfp_mask = mapping_gfp_constraint(mapping, ~__GFP_FS) | __GFP_NOFAIL; + for (i = 0; i < max_mirrors; i++) { + struct page *page; + struct bio *bio; + u8 *ptr; + bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->commit_total_bytes) @@ -3469,26 +3482,22 @@ static int write_dev_supers(struct btrfs_device *device, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); crypto_shash_final(shash, sb->csum); - /* One reference for us, and we leave it for the caller */ - bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE, - BTRFS_SUPER_INFO_SIZE); - if (!bh) { + page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT, + gfp_mask); + if (!page) { btrfs_err(device->fs_info, - "couldn't get super buffer head for bytenr %llu", + "couldn't get superblock page for bytenr %llu", bytenr); errors++; continue; } - memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE); + /* Bump the refcount for wait_dev_supers() */ + get_page(page); - /* one reference for submit_bh */ - get_bh(bh); - - set_buffer_uptodate(bh); - lock_buffer(bh); - bh->b_end_io = btrfs_end_buffer_write_sync; - bh->b_private = device; + ptr = kmap(page); + memcpy(ptr, sb, BTRFS_SUPER_INFO_SIZE); + kunmap(page); /* * we fua the first super. The others we allow @@ -3497,9 +3506,23 @@ static int write_dev_supers(struct btrfs_device *device, op_flags = REQ_SYNC | REQ_META | REQ_PRIO; if (i == 0 && !btrfs_test_opt(device->fs_info, NOBARRIER)) op_flags |= REQ_FUA; - ret = btrfsic_submit_bh(REQ_OP_WRITE, op_flags, bh); - if (ret) - errors++; + + /* + * Directly use BIOs here instead of relying on the page-cache + * to do I/O, so we don't loose the ability to do integrity + * checking. + */ + bio = bio_alloc(gfp_mask, 1); + bio_set_dev(bio, device->bdev); + bio->bi_iter.bi_sector = bytenr >> SECTOR_SHIFT; + bio->bi_private = device; + bio->bi_end_io = btrfs_end_super_write; + bio_add_page(bio, page, BTRFS_SUPER_INFO_SIZE, + offset_in_page(bytenr)); + + bio->bi_opf = REQ_OP_WRITE | op_flags; + + btrfsic_submit_bio(bio); } return errors < i ? 0 : -1; } @@ -3508,12 +3531,11 @@ static int write_dev_supers(struct btrfs_device *device, * Wait for write completion of superblocks done by write_dev_supers, * @max_mirrors same for write and wait phases. * - * Return number of errors when buffer head is not found or not marked up to + * Return number of errors when page is not found or not marked up to * date. */ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors) { - struct buffer_head *bh; int i; int errors = 0; bool primary_failed = false; @@ -3523,32 +3545,33 @@ static int wait_dev_supers(struct btrfs_device *device, int max_mirrors) max_mirrors = BTRFS_SUPER_MIRROR_MAX; for (i = 0; i < max_mirrors; i++) { + struct page *page; + bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->commit_total_bytes) break; - bh = __find_get_block(device->bdev, - bytenr / BTRFS_BDEV_BLOCKSIZE, - BTRFS_SUPER_INFO_SIZE); - if (!bh) { + page = find_get_page(device->bdev->bd_inode->i_mapping, + bytenr >> PAGE_SHIFT); + if (!page) { errors++; if (i == 0) primary_failed = true; continue; } - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) { + wait_on_page_locked(page); + if (PageError(page)) { errors++; if (i == 0) primary_failed = true; } /* drop our reference */ - brelse(bh); + put_page(page); /* drop the reference from the writing run */ - brelse(bh); + put_page(page); } /* log error, force error return */