path: root/fs
diff options
authorFilipe Manana <fdmanana@suse.com>2015-03-30 18:26:47 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-05-06 21:59:08 +0200
commit09ad914f6588c10c54cc5e4ca75ef671604e32b3 (patch)
treec2f9e8a1c273e7b569ffbb25a6cc6835864a4e3c /fs
parent81a65d1f0fcda11ff10f6a1bd0da5b39961bf493 (diff)
Btrfs: fix inode eviction infinite loop after extent_same ioctl
commit 113e8283869b9855c8b999796aadd506bbac155f upstream. If we pass a length of 0 to the extent_same ioctl, we end up locking an extent range with a start offset greater then its end offset (if the destination file's offset is greater than zero). This results in a warning from extent_io.c:insert_state through the following call chain: btrfs_extent_same() btrfs_double_lock() lock_extent_range() lock_extent(inode->io_tree, offset, offset + len - 1) lock_extent_bits() __set_extent_bit() insert_state() --> WARN_ON(end < start) This leads to an infinite loop when evicting the inode. This is the same problem that my previous patch titled "Btrfs: fix inode eviction infinite loop after cloning into it" addressed but for the extent_same ioctl instead of the clone ioctl. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fa7e6a373378..3e16042338e4 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2708,6 +2708,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
if (src == dst)
return -EINVAL;
+ if (len == 0)
+ return 0;
btrfs_double_lock(src, loff, dst, dst_loff, len);
ret = extent_same_check_offsets(src, loff, len);