[ 33/48] block: use i_size_write() in bd_set_size()

From: Greg Kroah-Hartman
Date: Mon Mar 18 2013 - 17:25:58 EST

3.4-stable review patch. If anyone has any objections, please let me know.


From: Guo Chao <yan@xxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Guo Chao <yan@xxxxxxxxxxxxxxxxxx>
Cc: M. Hindess <hindessm@xxxxxxxxxx>
Cc: Nikanth Karthikesan <knikanth@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Acked-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/block_dev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1086,7 +1086,9 @@ void bd_set_size(struct block_device *bd
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)

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/