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>
This commit is contained in:
Christoph Hellwig
2017-04-20 09:42:48 -07:00
committed by Darrick J. Wong
parent 37f7f9bbf3
commit 0c1d9e4a61
6 changed files with 41 additions and 122 deletions

View File

@@ -24,13 +24,6 @@ struct xfs_mount;
struct xfs_inode;
struct xfs_trans;
/*
* Extent state and extent format macros.
*/
#define XFS_EXTFMT_INODE(x) \
(xfs_sb_version_hasextflgbit(&((x)->i_mount->m_sb)) ? \
XFS_EXTFMT_HASSTATE : XFS_EXTFMT_NOSTATE)
/*
* Btree block header size depends on a superblock flag.
*/
@@ -139,4 +132,18 @@ extern int xfs_bmbt_change_owner(struct xfs_trans *tp, struct xfs_inode *ip,
extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
struct xfs_trans *, struct xfs_inode *, int);
/*
* Check that the extent does not contain an invalid unwritten extent flag.
*/
static inline bool xfs_bmbt_validate_extent(struct xfs_mount *mp, int whichfork,
struct xfs_bmbt_rec_host *ep)
{
if (ep->l0 >> (64 - BMBT_EXNTFLAG_BITLEN) == 0)
return true;
if (whichfork == XFS_DATA_FORK &&
xfs_sb_version_hasextflgbit(&mp->m_sb))
return true;
return false;
}
#endif /* __XFS_BMAP_BTREE_H__ */