xfs: remove the NULL fork handling in xfs_bmapi_read

Now that we fully verify the inode forks before they are added to the
inode cache, the crash reported in

  https://bugzilla.kernel.org/show_bug.cgi?id=204031

can't happen anymore, as we'll never let an inode that has inconsistent
nextents counts vs the presence of an in-core attr fork leak into the
inactivate code path.  So remove the work around to try to handle the
case, and just return an error and warn if the fork is not present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 76be1a18e2442f02199e93258b8afa23f52d0a9d..34518a6dc7376b3d268466764edf12a76d71fcee 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3891,7 +3891,8 @@ xfs_bmapi_read(
        int                     flags)
 {
        struct xfs_mount        *mp = ip->i_mount;
-       struct xfs_ifork        *ifp;
+       int                     whichfork = xfs_bmapi_whichfork(flags);
+       struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
        struct xfs_bmbt_irec    got;
        xfs_fileoff_t           obno;
        xfs_fileoff_t           end;
@@ -3899,12 +3900,14 @@ xfs_bmapi_read(
        int                     error;
        bool                    eof = false;
        int                     n = 0;
-       int                     whichfork = xfs_bmapi_whichfork(flags);
 
        ASSERT(*nmap >= 1);
        ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK | XFS_BMAPI_ENTIRE)));
        ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED|XFS_ILOCK_EXCL));
 
+       if (WARN_ON_ONCE(!ifp))
+               return -EFSCORRUPTED;
+
        if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(ip, whichfork)) ||
            XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BMAPIFORMAT)) {
                return -EFSCORRUPTED;
@@ -3915,21 +3918,6 @@ xfs_bmapi_read(
 
        XFS_STATS_INC(mp, xs_blk_mapr);
 
-       ifp = XFS_IFORK_PTR(ip, whichfork);
-       if (!ifp) {
-               /*
-                * A missing attr ifork implies that the inode says we're in
-                * extents or btree format but failed to pass the inode fork
-                * verifier while trying to load it.  Treat that as a file
-                * corruption too.
-                */
-#ifdef DEBUG
-               xfs_alert(mp, "%s: inode %llu missing fork %d",
-                               __func__, ip->i_ino, whichfork);
-#endif /* DEBUG */
-               return -EFSCORRUPTED;
-       }
-
        if (!(ifp->if_flags & XFS_IFEXTENTS)) {
                error = xfs_iread_extents(NULL, ip, whichfork);
                if (error)