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authorMiklos Szeredi <mszeredi@suse.cz>2011-02-24 15:49:53 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2011-02-24 08:55:01 -0800
commit8074b26f67165bf045d92e778c9c10dc5e207fc6 (patch)
tree7f4870224b54121fbfea83cd77ea41f7ab3a00d8 /mm
parent3c522cedb572bb8d2e4867f358bdaa7d0c53d88c (diff)
downloadop-kernel-dev-8074b26f67165bf045d92e778c9c10dc5e207fc6.zip
op-kernel-dev-8074b26f67165bf045d92e778c9c10dc5e207fc6.tar.gz
mm: fix refcounting in swapon
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(). Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/swapfile.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 07a458d..0341c57 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1940,7 +1940,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
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) {
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