Linux-ext4 Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Waiman Long <longman@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ext4@vger.kernel.org, cluster-devel@redhat.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH 05/12] gfs2: fix O_SYNC write handling
Date: Tue, 14 Jan 2020 17:12:18 +0100
Message-ID: <20200114161225.309792-6-hch@lst.de> (raw)
In-Reply-To: <20200114161225.309792-1-hch@lst.de>

Don't ignore the return value from generic_write_sync for the direct to
buffered I/O callback case when written is non-zero.  Also don't bother
to call generic_write_sync for the pure direct I/O case, as iomap_dio_rw
already takes care of that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/gfs2/file.c | 51 +++++++++++++++++++++++++-------------------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 21d032c4b077..86c0e61407b6 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -847,7 +847,7 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
 	struct gfs2_inode *ip = GFS2_I(inode);
-	ssize_t written = 0, ret;
+	ssize_t ret = 0;
 
 	ret = gfs2_rsqa_alloc(ip);
 	if (ret)
@@ -882,52 +882,51 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		loff_t pos, endbyte;
 		ssize_t buffered;
 
-		written = gfs2_file_direct_write(iocb, from);
-		if (written < 0 || !iov_iter_count(from))
+		ret = gfs2_file_direct_write(iocb, from);
+		if (ret < 0 || !iov_iter_count(from))
 			goto out_unlock;
 
 		current->backing_dev_info = inode_to_bdi(inode);
-		ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
+		buffered = iomap_file_buffered_write(iocb, from,
+						     &gfs2_iomap_ops);
 		current->backing_dev_info = NULL;
-		if (unlikely(ret < 0))
+		if (unlikely(buffered <= 0)) {
+			if (buffered < 0)
+				ret = buffered;
 			goto out_unlock;
-		buffered = ret;
+		}
 
 		/*
 		 * We need to ensure that the page cache pages are written to
 		 * disk and invalidated to preserve the expected O_DIRECT
-		 * semantics.
+		 * semantics.  If the writeback or invalidate fails only report
+		 * the direct I/O range as we don't know if the buffered pages
+		 * made it to disk.
 		 */
 		pos = iocb->ki_pos;
 		endbyte = pos + buffered - 1;
 		ret = filemap_write_and_wait_range(mapping, pos, endbyte);
-		if (!ret) {
-			iocb->ki_pos += buffered;
-			written += buffered;
-			invalidate_mapping_pages(mapping,
-						 pos >> PAGE_SHIFT,
-						 endbyte >> PAGE_SHIFT);
-		} else {
-			/*
-			 * We don't know how much we wrote, so just return
-			 * the number of bytes which were direct-written
-			 */
-		}
+		if (ret)
+			goto out_unlock;
+
+		invalidate_mapping_pages(mapping, pos >> PAGE_SHIFT,
+					 endbyte >> PAGE_SHIFT);
+		ret += buffered;
 	} else {
 		current->backing_dev_info = inode_to_bdi(inode);
 		ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
 		current->backing_dev_info = NULL;
-		if (likely(ret > 0))
-			iocb->ki_pos += ret;
+		if (unlikely(ret <= 0))
+			goto out_unlock;
 	}
 
+	iocb->ki_pos += ret;
+	inode_unlock(inode);
+	return generic_write_sync(iocb, ret);
+
 out_unlock:
 	inode_unlock(inode);
-	if (likely(ret > 0)) {
-		/* Handle various SYNC-type writes */
-		ret = generic_write_sync(iocb, ret);
-	}
-	return written ? written : ret;
+	return ret;
 }
 
 static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
-- 
2.24.1


  parent reply index

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-14 16:12 RFC: hold i_rwsem until aio completes Christoph Hellwig
2020-01-14 16:12 ` [PATCH 01/12] mm: fix a comment in sys_swapon Christoph Hellwig
2020-02-10 23:29   ` Andrew Morton
2020-02-12  7:37     ` Christoph Hellwig
2020-01-14 16:12 ` [PATCH 02/12] locking/rwsem: Exit early when held by an anonymous owner Christoph Hellwig
2020-01-14 18:17   ` Waiman Long
2020-01-14 18:25     ` Christoph Hellwig
2020-01-14 18:33       ` Waiman Long
2020-01-14 18:55       ` Waiman Long
2020-01-14 16:12 ` [PATCH 03/12] xfs: fix IOCB_NOWAIT handling in xfs_file_dio_aio_read Christoph Hellwig
2020-01-14 16:12 ` [PATCH 04/12] gfs2: move setting current->backing_dev_info Christoph Hellwig
2020-01-14 16:12 ` Christoph Hellwig [this message]
2020-02-06 15:31   ` [Cluster-devel] [PATCH 05/12] gfs2: fix O_SYNC write handling Andreas Gruenbacher
2020-01-14 16:12 ` [PATCH 06/12] iomap: pass a flags value to iomap_dio_rw Christoph Hellwig
2020-01-14 16:12 ` [PATCH 07/12] iomap: allow holding i_rwsem until aio completion Christoph Hellwig
2020-01-14 16:12 ` [PATCH 08/12] ext4: hold i_rwsem until AIO completes Christoph Hellwig
2020-01-14 21:50   ` Theodore Y. Ts'o
2020-01-15  6:48     ` Christoph Hellwig
2020-01-14 16:12 ` [PATCH 09/12] gfs2: " Christoph Hellwig
2020-01-14 16:12 ` [PATCH 10/12] xfs: " Christoph Hellwig
2020-01-14 16:12 ` [PATCH 11/12] xfs: don't set IOMAP_DIO_SYNCHRONOUS for unaligned I/O Christoph Hellwig
2020-01-14 16:12 ` [PATCH 12/12] iomap: remove the inode_dio_begin/end calls Christoph Hellwig
2020-01-14 18:47 ` RFC: hold i_rwsem until aio completes Matthew Wilcox
2020-01-15  6:54   ` Christoph Hellwig
2020-01-14 19:27 ` Jason Gunthorpe
2020-01-15  6:56   ` Christoph Hellwig
2020-01-15 13:24     ` Jason Gunthorpe
2020-01-15 14:33       ` Peter Zijlstra
2020-01-15 14:49         ` Jason Gunthorpe
2020-01-15 19:03           ` Waiman Long
2020-01-15 19:07             ` Christoph Hellwig
2020-01-18 22:40         ` Matthew Wilcox
2020-01-15 15:36       ` Christoph Hellwig
2020-01-15 16:26         ` Jason Gunthorpe
2020-01-16 14:00 ` Jan Kara
2020-02-03 17:44   ` Christoph Hellwig
2020-01-18  9:28 ` Dave Chinner
2020-02-03 17:46   ` Christoph Hellwig
2020-02-03 23:02     ` Dave Chinner

Reply instructions:

You may reply publically 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=20200114161225.309792-6-hch@lst.de \
    --to=hch@lst.de \
    --cc=akpm@linux-foundation.org \
    --cc=cluster-devel@redhat.com \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=longman@redhat.com \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=will@kernel.org \
    /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

Linux-ext4 Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-ext4/0 linux-ext4/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-ext4 linux-ext4/ https://lore.kernel.org/linux-ext4 \
		linux-ext4@vger.kernel.org
	public-inbox-index linux-ext4

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-ext4


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git