diff options
authorDarrick J. Wong <darrick.wong@oracle.com>2017-06-19 13:19:08 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-20 08:19:58 +0200
commit621d0b75a3476bce5f1d4e13bb99deaf57b9289d (patch)
parent8913492d12b1e71bd89bb234408483b7c56700e0 (diff)
xfs: don't allow bmap on rt files
commit 61d819e7bcb7f33da710bf3f5dcb2bcf1e48203c upstream. bmap returns a dumb LBA address but not the block device that goes with that LBA. Swapfiles don't care about this and will blindly assume that the data volume is the correct blockdev, which is totally bogus for files on the rt subvolume. This results in the swap code doing IOs to arbitrary locations on the data device(!) if the passed in mapping is a realtime file, so just turn off bmap for rt files. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 578981412615..f750d888bd17 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1566,9 +1566,12 @@ xfs_vm_bmap(
* The swap code (ab-)uses ->bmap to get a block mapping and then
* bypasseѕ the file system for actual I/O. We really can't allow
* that on reflinks inodes, so we have to skip out here. And yes,
- * 0 is the magic code for a bmap error..
+ * 0 is the magic code for a bmap error.
+ *
+ * Since we don't pass back blockdev info, we can't return bmap
+ * information for rt files either.
- if (xfs_is_reflink_inode(ip)) {
+ if (xfs_is_reflink_inode(ip) || XFS_IS_REALTIME_INODE(ip)) {
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return 0;