[PATCH] xfs: try to idiot-proof the allocators

[PATCH] xfs: try to idiot-proof the allocators

[Darrick J. Wong]

From: Darrick J. Wong <djwong@kernel.org>

In porting his development branch to 6.3-rc1, yours truly has
repeatedly screwed up the args->pag being fed to the xfs_alloc_vextent*
functions.  Add some debugging assertions to test the preconditions
required of the callers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/libxfs/xfs_alloc.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index b58e8e2daa72..e0c3527de6e4 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -3410,6 +3410,9 @@ xfs_alloc_vextent_this_ag(
 	xfs_agnumber_t		minimum_agno;
 	int			error;
 
+	ASSERT(args->pag != NULL);
+	ASSERT(args->pag->pag_agno == agno);
+
 	args->agno = agno;
 	args->agbno = 0;
 	error = xfs_alloc_vextent_check_args(args, XFS_AGB_TO_FSB(mp, agno, 0),
@@ -3525,6 +3528,8 @@ xfs_alloc_vextent_start_ag(
 	bool			bump_rotor = false;
 	int			error;
 
+	ASSERT(args->pag == NULL);
+
 	args->agno = NULLAGNUMBER;
 	args->agbno = NULLAGBLOCK;
 	error = xfs_alloc_vextent_check_args(args, target, &minimum_agno);
@@ -3573,6 +3578,8 @@ xfs_alloc_vextent_first_ag(
 	xfs_agnumber_t		start_agno;
 	int			error;
 
+	ASSERT(args->pag == NULL);
+
 	args->agno = NULLAGNUMBER;
 	args->agbno = NULLAGBLOCK;
 	error = xfs_alloc_vextent_check_args(args, target, &minimum_agno);
@@ -3601,6 +3608,9 @@ xfs_alloc_vextent_exact_bno(
 	xfs_agnumber_t		minimum_agno;
 	int			error;
 
+	ASSERT(args->pag != NULL);
+	ASSERT(args->pag->pag_agno == XFS_FSB_TO_AGNO(mp, target));
+
 	args->agno = XFS_FSB_TO_AGNO(mp, target);
 	args->agbno = XFS_FSB_TO_AGBNO(mp, target);
 	error = xfs_alloc_vextent_check_args(args, target, &minimum_agno);
@@ -3633,6 +3643,9 @@ xfs_alloc_vextent_near_bno(
 	bool			needs_perag = args->pag == NULL;
 	int			error;
 
+	if (!needs_perag)
+		ASSERT(args->pag->pag_agno == XFS_FSB_TO_AGNO(mp, target));
+
 	args->agno = XFS_FSB_TO_AGNO(mp, target);
 	args->agbno = XFS_FSB_TO_AGBNO(mp, target);
 	error = xfs_alloc_vextent_check_args(args, target, &minimum_agno);

Re: [PATCH] xfs: try to idiot-proof the allocators

[Dave Chinner]

On Thu, Mar 09, 2023 at 12:14:30PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> In porting his development branch to 6.3-rc1, yours truly has
> repeatedly screwed up the args->pag being fed to the xfs_alloc_vextent*
> functions.  Add some debugging assertions to test the preconditions
> required of the callers.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  fs/xfs/libxfs/xfs_alloc.c |   13 +++++++++++++
>  1 file changed, 13 insertions(+)

Looks good.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
-- 
Dave Chinner
david@fromorbit.com