xfs: assert that we don't enter agfl freeing with a non-permanent tra…

…nsaction Block allocation requires a permanent transaction for deferred AGFL frees. Add an assert in the block allocation path to make explicit and obvious to future callers the requirement of a transaction with a permanent reservation. Reported-by: Darrick J. Wong <[email protected]> Signed-off-by: Brian Foster <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> [darrick: split this out from the previous patch per hch request] Signed-off-by: Darrick J. Wong <[email protected]>
chewitt · Apr 23, 2019 · 362f5e7 · 362f5e7
1 parent 945c941
commit 362f5e7
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
@@ -2243,6 +2243,9 @@ xfs_alloc_fix_freelist(
 	xfs_extlen_t		need;	/* total blocks needed in freelist */
 	int			error = 0;
 
+	/* deferred ops (AGFL block frees) require permanent transactions */
+	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+
 	if (!pag->pagf_init) {
 		error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
 		if (error)