diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-03 09:11:36 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2016-10-05 16:26:04 -0700 |
| commit | db1327b16c2b24e28d1e5899bced89db9ae6538e (patch) | |
| tree | 26387f590ce880b409245a80c40dabe47a7dc6e5 /fs/xfs/xfs_aops.c | |
| parent | 43caeb187deb92b3cc343fce9c2310512f6ac9cd (diff) | |
| download | linux-db1327b16c2b24e28d1e5899bced89db9ae6538e.tar.bz2 | |
xfs: report shared extent mappings to userspace correctly
Report shared extents through the iomap interface so that FIEMAP flags
shared blocks accurately. Have xfs_vm_bmap return zero for reflinked
files because the bmap-based swap code requires static block mappings,
which is incompatible with copy on write.
NOTE: Existing userspace bmap users such as lilo will have the same
problem with reflink files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/xfs_aops.c')
| -rw-r--r-- | fs/xfs/xfs_aops.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index f6f5bbc39dda..2f4a15ec9ee9 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1508,6 +1508,17 @@ xfs_vm_bmap( trace_xfs_vm_bmap(XFS_I(inode)); xfs_ilock(ip, XFS_IOLOCK_SHARED); + + /* + * 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.. + */ + if (xfs_is_reflink_inode(ip)) { + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return 0; + } filemap_write_and_wait(mapping); xfs_iunlock(ip, XFS_IOLOCK_SHARED); return generic_block_bmap(mapping, block, xfs_get_blocks); |