xfs: simplify validation of the unwritten extent bit
authorChristoph Hellwig <hch@lst.de>
Thu, 20 Apr 2017 16:42:48 +0000 (09:42 -0700)
committerDarrick J. Wong <darrick.wong@oracle.com>
Tue, 25 Apr 2017 16:40:41 +0000 (09:40 -0700)
commit0c1d9e4a61590c2a4d657d1deddd1674f1565097
tree06679ca9c93c0224b4d7edb65b08eed486acb489
parent37f7f9bbf3b914e94f81426f6f59a3f97f4dc562
xfs: simplify validation of the unwritten extent bit

XFS only supports the unwritten extent bit in the data fork, and only if
the file system has a version 5 superblock or the unwritten extent
feature bit.

We currently have two routines that validate the invariant:
xfs_check_nostate_extents which return -EFSCORRUPTED when it's not met,
and xfs_validate_extent that triggers and assert in debug build.

Both of them iterate over all extents of an inode fork when called,
which isn't very efficient.

This patch instead adds a new helper that verifies the invariant one
extent at a time, and calls it from the places where we iterate over
all extents to converted them from or two the in-memory format.  The
callers then return -EFSCORRUPTED when reading invalid extents from
disk, or trigger an assert when writing them to disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
fs/xfs/libxfs/xfs_bmap.c
fs/xfs/libxfs/xfs_bmap.h
fs/xfs/libxfs/xfs_bmap_btree.c
fs/xfs/libxfs/xfs_bmap_btree.h
fs/xfs/libxfs/xfs_format.h
fs/xfs/libxfs/xfs_inode_fork.c