[ 3.5.y.z extended stable ] Patch "block: use i_size_write() in bd_set_size()" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Wed Mar 20 10:43:41 UTC 2013

This is a note to let you know that I have just added a patch titled

    block: use i_size_write() in bd_set_size()

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



>From f1444f07124e83568c5b9122e909f4126981380c Mon Sep 17 00:00:00 2001
From: Guo Chao <yan at linux.vnet.ibm.com>
Date: Thu, 21 Feb 2013 15:16:42 -0800
Subject: [PATCH] block: use i_size_write() in bd_set_size()

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

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)

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