linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	Ming Lei <ming.lei@redhat.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	linux-xfs@vger.kernel.org
Subject: [PATCH V9 13/19] iomap & xfs: only account for new added page
Date: Tue, 13 Nov 2018 23:14:59 +0800	[thread overview]
Message-ID: <20181113151505.15498-14-ming.lei@redhat.com> (raw)
In-Reply-To: <20181113151505.15498-1-ming.lei@redhat.com>

After multi-page is enabled, one new page may be merged to a segment
even though it is a new added page.

This patch deals with this issue by post-check in case of merge, and
only a freshly new added page need to be dealt with for iomap & xfs.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/iomap.c          | 22 ++++++++++++++--------
 fs/xfs/xfs_aops.c   | 10 ++++++++--
 include/linux/bio.h | 11 +++++++++++
 3 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/fs/iomap.c b/fs/iomap.c
index df0212560b36..a1b97a5c726a 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -288,6 +288,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	loff_t orig_pos = pos;
 	unsigned poff, plen;
 	sector_t sector;
+	bool need_account = false;
 
 	if (iomap->type == IOMAP_INLINE) {
 		WARN_ON_ONCE(pos);
@@ -313,18 +314,15 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	 */
 	sector = iomap_sector(iomap, pos);
 	if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
-		if (__bio_try_merge_page(ctx->bio, page, plen, poff))
+		if (__bio_try_merge_page(ctx->bio, page, plen, poff)) {
+			need_account = iop && bio_is_last_segment(ctx->bio,
+					page, plen, poff);
 			goto done;
+		}
 		is_contig = true;
 	}
 
-	/*
-	 * If we start a new segment we need to increase the read count, and we
-	 * need to do so before submitting any previous full bio to make sure
-	 * that we don't prematurely unlock the page.
-	 */
-	if (iop)
-		atomic_inc(&iop->read_count);
+	need_account = true;
 
 	if (!ctx->bio || !is_contig || bio_full(ctx->bio)) {
 		gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
@@ -347,6 +345,14 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	__bio_add_page(ctx->bio, page, plen, poff);
 done:
 	/*
+	 * If we add a new page we need to increase the read count, and we
+	 * need to do so before submitting any previous full bio to make sure
+	 * that we don't prematurely unlock the page.
+	 */
+	if (iop && need_account)
+		atomic_inc(&iop->read_count);
+
+	/*
 	 * Move the caller beyond our range so that it keeps making progress.
 	 * For that we have to include any leading non-uptodate ranges, but
 	 * we can skip trailing ones as they will be handled in the next
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 1f1829e506e8..d8e9cc9f751a 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -603,6 +603,7 @@ xfs_add_to_ioend(
 	unsigned		len = i_blocksize(inode);
 	unsigned		poff = offset & (PAGE_SIZE - 1);
 	sector_t		sector;
+	bool			need_account;
 
 	sector = xfs_fsb_to_db(ip, wpc->imap.br_startblock) +
 		((offset - XFS_FSB_TO_B(mp, wpc->imap.br_startoff)) >> 9);
@@ -617,13 +618,18 @@ xfs_add_to_ioend(
 	}
 
 	if (!__bio_try_merge_page(wpc->ioend->io_bio, page, len, poff)) {
-		if (iop)
-			atomic_inc(&iop->write_count);
+		need_account = true;
 		if (bio_full(wpc->ioend->io_bio))
 			xfs_chain_bio(wpc->ioend, wbc, bdev, sector);
 		__bio_add_page(wpc->ioend->io_bio, page, len, poff);
+	} else {
+		need_account = iop && bio_is_last_segment(wpc->ioend->io_bio,
+				page, len, poff);
 	}
 
+	if (iop && need_account)
+		atomic_inc(&iop->write_count);
+
 	wpc->ioend->io_size += len;
 }
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 1a2430a8b89d..5040e9a2eb09 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -341,6 +341,17 @@ static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
 	return &bio->bi_io_vec[bio->bi_vcnt - 1];
 }
 
+/* iomap needs this helper to deal with sub-pagesize bvec */
+static inline bool bio_is_last_segment(struct bio *bio, struct page *page,
+		unsigned int len, unsigned int off)
+{
+	struct bio_vec bv;
+
+	bvec_last_segment(bio_last_bvec_all(bio), &bv);
+
+	return bv.bv_page == page && bv.bv_len == len && bv.bv_offset == off;
+}
+
 enum bip_flags {
 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
-- 
2.9.5


  parent reply	other threads:[~2018-11-13 15:16 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-13 15:14 [PATCH V9 00/19] block: support multi-page bvec Ming Lei
2018-11-13 15:14 ` [PATCH V9 01/19] block: introduce multi-page page bvec helpers Ming Lei
2018-11-13 15:14 ` [PATCH V9 02/19] block: introduce bio_for_each_bvec() Ming Lei
2018-11-13 15:14 ` [PATCH V9 03/19] block: use bio_for_each_bvec() to compute multi-page bvec count Ming Lei
2018-11-13 15:14 ` [PATCH V9 04/19] block: use bio_for_each_bvec() to map sg Ming Lei
2018-11-13 15:14 ` [PATCH V9 05/19] block: introduce bvec_last_segment() Ming Lei
2018-11-13 15:14 ` [PATCH V9 06/19] fs/buffer.c: use bvec iterator to truncate the bio Ming Lei
2018-11-13 15:14 ` [PATCH V9 07/19] btrfs: use bvec_last_segment to get bio's last page Ming Lei
2018-11-13 15:14 ` [PATCH V9 08/19] btrfs: move bio_pages_all() to btrfs Ming Lei
2018-11-13 15:14 ` [PATCH V9 09/19] block: introduce bio_bvecs() Ming Lei
2018-11-13 15:14 ` [PATCH V9 10/19] block: loop: pass multi-page bvec to iov_iter Ming Lei
2018-11-13 15:14 ` [PATCH V9 11/19] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages() Ming Lei
2018-11-13 15:14 ` [PATCH V9 12/19] block: allow bio_for_each_segment_all() to iterate over multi-page bvec Ming Lei
2018-11-13 15:14 ` Ming Lei [this message]
2018-11-13 15:15 ` [PATCH V9 14/19] block: enable multipage bvecs Ming Lei
2018-11-13 15:15 ` [PATCH V9 15/19] block: always define BIO_MAX_PAGES as 256 Ming Lei
2018-11-13 15:15 ` [PATCH V9 16/19] block: document usage of bio iterator helpers Ming Lei
2018-11-13 15:15 ` [PATCH V9 17/19] block: don't use bio->bi_vcnt to figure out segment number Ming Lei
2018-11-13 15:15 ` [PATCH V9 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE Ming Lei
2018-11-13 15:15 ` [PATCH V9 19/19] block: kill BLK_MQ_F_SG_MERGE Ming Lei
2018-11-14  2:44 ` [PATCH V9 00/19] block: support multi-page bvec Dave Chinner
2018-11-14  2:57   ` Ming Lei
2018-11-14 15:22   ` Christoph Hellwig
2018-11-15  9:35     ` Ming Lei

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20181113151505.15498-14-ming.lei@redhat.com \
    --to=ming.lei@redhat.com \
    --cc=axboe@kernel.dk \
    --cc=darrick.wong@oracle.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    --subject='Re: [PATCH V9 13/19] iomap & xfs: only account for new added page' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).