Patchwork [024/150] block: use i_size_write() in bd_set_size()

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Submitter Luis Henriques
Date March 26, 2013, 3:18 p.m.
Message ID <1364311249-14454-25-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/231415/
State New
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Luis Henriques - March 26, 2013, 3:18 p.m.
3.5.7.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Guo Chao <yan@linux.vnet.ibm.com>

commit d646a02a9d44d1421f273ae3923d97b47b918176 upstream.

blkdev_ioctl(GETBLKSIZE) uses i_size_read() to read size of block device.
If we update block size directly, reader may see intermediate result in
some machines and configurations.  Use i_size_write() instead.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: M. Hindess <hindessm@uk.ibm.com>
Cc: Nikanth Karthikesan <knikanth@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 fs/block_dev.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/block_dev.c b/fs/block_dev.c
index db64e31..77e86b3 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1086,7 +1086,9 @@  void bd_set_size(struct block_device *bdev, loff_t size)
 {
 	unsigned bsize = bdev_logical_block_size(bdev);
 
-	bdev->bd_inode->i_size = size;
+	mutex_lock(&bdev->bd_inode->i_mutex);
+	i_size_write(bdev->bd_inode, size);
+	mutex_unlock(&bdev->bd_inode->i_mutex);
 	while (bsize < PAGE_CACHE_SIZE) {
 		if (size & bsize)
 			break;