Messages in this thread Patch in this message | | | Subject | [PATCH] mm: fix refcounting in swapon | From | Miklos Szeredi <> | Date | Thu, 24 Feb 2011 15:49:53 +0100 |
| |
From: Miklos Szeredi <mszeredi@suse.cz>
Grab a reference to bdev before calling blkdev_get(), which expects the refcount to be already incremented and either returns success or decrements the refcount and returns an error.
The bug was introduced by e525fd89 (block: make blkdev_get/put() handle exclusive access), which didn't take into account this behavior of blkdev_get().
CC: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux.git/mm/swapfile.c =================================================================== --- linux.git.orig/mm/swapfile.c 2011-02-24 15:29:26.000000000 +0100 +++ linux.git/mm/swapfile.c 2011-02-24 15:32:31.000000000 +0100 @@ -1940,7 +1940,7 @@ SYSCALL_DEFINE2(swapon, const char __use error = -EINVAL; if (S_ISBLK(inode->i_mode)) { - bdev = I_BDEV(inode); + bdev = bdgrab(I_BDEV(inode)); error = blkdev_get(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL, sys_swapon); if (error < 0) {
| |