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author | Filipe Manana <fdmanana@suse.com> | 2015-03-30 18:26:47 +0100 |
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committer | Luis Henriques <luis.henriques@canonical.com> | 2015-05-06 10:24:19 +0100 |
commit | ac52f6f547fdc437de6ab70db487376ecc45639e (patch) | |
tree | dd947b2ebbd9bc129cd8b972d167e19fb2aacf2b /fs/btrfs | |
parent | 9ee588e8913af407a3d39238ec8e380ef80ce95e (diff) | |
download | linux-stable-ac52f6f547fdc437de6ab70db487376ecc45639e.tar.gz linux-stable-ac52f6f547fdc437de6ab70db487376ecc45639e.tar.bz2 linux-stable-ac52f6f547fdc437de6ab70db487376ecc45639e.zip |
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: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r-- | fs/btrfs/ioctl.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 4e395f3f251d..c5b7213f267a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2941,6 +2941,9 @@ 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); |