[PATCH] libxfs: deferred items should call xfs_perag_intent_{get,put}

["Darrick J. Wong" <djwong@kernel.org>]

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

Make the intent item _get_group and _put_group functions call
xfs_perag_intent_{get,put} to match the kernel.  In userspace they're
the same thing so this makes no difference.  However, let's not leave
unnecessary discrepancies with the kernel code.

Fixes: 7cb26322f74 ("xfs: allow queued AG intents to drain before scrubbing")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 libxfs/defer_item.c |   42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/libxfs/defer_item.c b/libxfs/defer_item.c
index dc00d6d671d..6c5c7dd5677 100644
--- a/libxfs/defer_item.c
+++ b/libxfs/defer_item.c
@@ -70,7 +70,7 @@ xfs_extent_free_create_done(
 	return NULL;
 }
 
-/* Take a passive ref to the AG containing the space we're freeing. */
+/* Take an active ref to the AG containing the space we're freeing. */
 void
 xfs_extent_free_get_group(
 	struct xfs_mount		*mp,
@@ -79,15 +79,15 @@ xfs_extent_free_get_group(
 	xfs_agnumber_t			agno;
 
 	agno = XFS_FSB_TO_AGNO(mp, xefi->xefi_startblock);
-	xefi->xefi_pag = xfs_perag_get(mp, agno);
+	xefi->xefi_pag = xfs_perag_intent_get(mp, agno);
 }
 
-/* Release a passive AG ref after some freeing work. */
+/* Release an active AG ref after some freeing work. */
 static inline void
 xfs_extent_free_put_group(
 	struct xfs_extent_free_item	*xefi)
 {
-	xfs_perag_put(xefi->xefi_pag);
+	xfs_perag_intent_put(xefi->xefi_pag);
 }
 
 /* Process a free extent. */
@@ -104,6 +104,7 @@ xfs_extent_free_finish_item(
 	int				error;
 
 	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
+
 	oinfo.oi_owner = xefi->xefi_owner;
 	if (xefi->xefi_flags & XFS_EFI_ATTR_FORK)
 		oinfo.oi_flags |= XFS_OWNER_INFO_ATTR_FORK;
@@ -166,6 +167,7 @@ xfs_agfl_free_finish_item(
 	xfs_agblock_t			agbno;
 
 	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
+
 	ASSERT(xefi->xefi_blockcount == 1);
 	agbno = XFS_FSB_TO_AGBNO(mp, xefi->xefi_startblock);
 	oinfo.oi_owner = xefi->xefi_owner;
@@ -232,7 +234,7 @@ xfs_rmap_update_create_done(
 	return NULL;
 }
 
-/* Take a passive ref to the AG containing the space we're rmapping. */
+/* Take an active ref to the AG containing the space we're rmapping. */
 void
 xfs_rmap_update_get_group(
 	struct xfs_mount	*mp,
@@ -241,15 +243,15 @@ xfs_rmap_update_get_group(
 	xfs_agnumber_t	agno;
 
 	agno = XFS_FSB_TO_AGNO(mp, ri->ri_bmap.br_startblock);
-	ri->ri_pag = xfs_perag_get(mp, agno);
+	ri->ri_pag = xfs_perag_intent_get(mp, agno);
 }
 
-/* Release a passive AG ref after finishing rmapping work. */
+/* Release an active AG ref after finishing rmapping work. */
 static inline void
 xfs_rmap_update_put_group(
 	struct xfs_rmap_intent	*ri)
 {
-	xfs_perag_put(ri->ri_pag);
+	xfs_perag_intent_put(ri->ri_pag);
 }
 
 /* Process a deferred rmap update. */
@@ -344,7 +346,7 @@ xfs_refcount_update_create_done(
 	return NULL;
 }
 
-/* Take a passive ref to the AG containing the space we're refcounting. */
+/* Take an active ref to the AG containing the space we're refcounting. */
 void
 xfs_refcount_update_get_group(
 	struct xfs_mount		*mp,
@@ -353,15 +355,15 @@ xfs_refcount_update_get_group(
 	xfs_agnumber_t			agno;
 
 	agno = XFS_FSB_TO_AGNO(mp, ri->ri_startblock);
-	ri->ri_pag = xfs_perag_get(mp, agno);
+	ri->ri_pag = xfs_perag_intent_get(mp, agno);
 }
 
-/* Release a passive AG ref after finishing refcounting work. */
+/* Release an active AG ref after finishing refcounting work. */
 static inline void
 xfs_refcount_update_put_group(
 	struct xfs_refcount_intent	*ri)
 {
-	xfs_perag_put(ri->ri_pag);
+	xfs_perag_intent_put(ri->ri_pag);
 }
 
 /* Process a deferred refcount update. */
@@ -461,7 +463,7 @@ xfs_bmap_update_create_done(
 	return NULL;
 }
 
-/* Take a passive ref to the AG containing the space we're mapping. */
+/* Take an active ref to the AG containing the space we're mapping. */
 void
 xfs_bmap_update_get_group(
 	struct xfs_mount	*mp,
@@ -470,15 +472,23 @@ xfs_bmap_update_get_group(
 	xfs_agnumber_t		agno;
 
 	agno = XFS_FSB_TO_AGNO(mp, bi->bi_bmap.br_startblock);
-	bi->bi_pag = xfs_perag_get(mp, agno);
+
+	/*
+	 * Bump the intent count on behalf of the deferred rmap and refcount
+	 * intent items that that we can queue when we finish this bmap work.
+	 * This new intent item will bump the intent count before the bmap
+	 * intent drops the intent count, ensuring that the intent count
+	 * remains nonzero across the transaction roll.
+	 */
+	bi->bi_pag = xfs_perag_intent_get(mp, agno);
 }
 
-/* Release a passive AG ref after finishing mapping work. */
+/* Release an active AG ref after finishing mapping work. */
 static inline void
 xfs_bmap_update_put_group(
 	struct xfs_bmap_intent	*bi)
 {
-	xfs_perag_put(bi->bi_pag);
+	xfs_perag_intent_put(bi->bi_pag);
 }
 
 /* Process a deferred rmap update. */