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From:   Alex Dewar <alex.dewar90@gmail.com>
To:     Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>,
        Goldwyn Rodrigues <rgoldwyn@suse.com>,
        linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Alex Dewar <alex.dewar90@gmail.com>
Subject: [PATCH] btrfs: check return value of filemap_fdatawrite_range()
Date:   Fri, 21 Aug 2020 13:41:54 +0100
Message-Id: <20200821124154.10218-1-alex.dewar90@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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In btrfs_dio_imap_begin(), filemap_fdatawrite_range() is called without
checking the return value. Add a check to catch errors.

Fixes: c0aaf9b7a114f ("btrfs: switch to iomap_dio_rw() for dio")
Addresses-Coverity: ("Unused value")
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
---
 fs/btrfs/inode.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7b57aaa1f9acc..38fde20b4a81b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7347,9 +7347,12 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
 	 * outstanding dirty pages are on disk.
 	 */
 	if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
-		     &BTRFS_I(inode)->runtime_flags))
+		     &BTRFS_I(inode)->runtime_flags)) {
 		ret = filemap_fdatawrite_range(inode->i_mapping, start,
 					       start + length - 1);
+		if (ret)
+			return ret;
+	}
 
 	dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS);
 	if (!dio_data)
-- 
2.28.0