xfs: idiotproof defer op type configuration

Recently, we forgot to port a new defer op type to xfsprogs, which
caused us some userspace pain.  Reorganize the way we make libxfs
clients supply defer op type information so that all type information
has to be provided at build time instead of risky runtime dynamic
configuration.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

2 files changed, 13 insertions, 10 deletions

diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
index e792b167150a..277117a8ad13 100644
--- a/fs/xfs/libxfs/xfs_defer.c
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -172,7 +172,13 @@
  * reoccur.
  */
 
-static const struct xfs_defer_op_type *defer_op_types[XFS_DEFER_OPS_TYPE_MAX];
+static const struct xfs_defer_op_type *defer_op_types[] = {
+        [XFS_DEFER_OPS_TYPE_BMAP]       = &xfs_bmap_update_defer_type,
+        [XFS_DEFER_OPS_TYPE_REFCOUNT]   = &xfs_refcount_update_defer_type,
+        [XFS_DEFER_OPS_TYPE_RMAP]       = &xfs_rmap_update_defer_type,
+        [XFS_DEFER_OPS_TYPE_FREE]       = &xfs_extent_free_defer_type,
+        [XFS_DEFER_OPS_TYPE_AGFL_FREE]  = &xfs_agfl_free_defer_type,
+};
 
 /*
  * For each pending item in the intake list, log its intent item and the
@@ -488,6 +494,7 @@ xfs_defer_add(
         struct xfs_defer_pending        *dfp = NULL;
 
         ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+        BUILD_BUG_ON(ARRAY_SIZE(defer_op_types) != XFS_DEFER_OPS_TYPE_MAX);
 
         /*
          * Add the item to a pending item at the end of the intake list.
@@ -517,14 +524,6 @@ xfs_defer_add(
         dfp->dfp_count++;
 }
 
-/* Initialize a deferred operation list. */
-void
-xfs_defer_init_op_type(
-        const struct xfs_defer_op_type  *type)
-{
-        defer_op_types[type->type] = type;
-}
-
 /*
  * Move deferred ops from one transaction to another and reset the source to
  * initial state. This is primarily used to carry state forward across
diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
index 2584a5b95b0d..0a4b88e3df74 100644
--- a/fs/xfs/libxfs/xfs_defer.h
+++ b/fs/xfs/libxfs/xfs_defer.h
@@ -56,6 +56,10 @@ struct xfs_defer_op_type {
         void (*log_item)(struct xfs_trans *, void *, struct list_head *);
 };
 
-void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
+extern const struct xfs_defer_op_type xfs_bmap_update_defer_type;
+extern const struct xfs_defer_op_type xfs_refcount_update_defer_type;
+extern const struct xfs_defer_op_type xfs_rmap_update_defer_type;
+extern const struct xfs_defer_op_type xfs_extent_free_defer_type;
+extern const struct xfs_defer_op_type xfs_agfl_free_defer_type;
 
 #endif /* __XFS_DEFER_H__ */