Merge tag 'intents-perag-refs-6.4_2023-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into guilt/xfs-for-next

xfs: make intent items take a perag reference [v24.5]

Now that we've cleaned up some code warts in the deferred work item
processing code, let's make intent items take an active perag reference
from their creation until they are finally freed by the defer ops
machinery.  This change facilitates the scrub drain in the next patchset
and will make it easier for the future AG removal code to detect a busy
AG in need of quiescing.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 38 insertions, 16 deletions

diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
index 011b50469301..38b66fcfddc8 100644
--- a/fs/xfs/xfs_extfree_item.c
+++ b/fs/xfs/xfs_extfree_item.c
@@ -351,8 +351,6 @@ xfs_trans_free_extent(
 	struct xfs_mount		*mp = tp->t_mountp;
 	struct xfs_extent		*extp;
 	uint				next_extent;
-	xfs_agnumber_t			agno = XFS_FSB_TO_AGNO(mp,
-							xefi->xefi_startblock);
 	xfs_agblock_t			agbno = XFS_FSB_TO_AGBNO(mp,
 							xefi->xefi_startblock);
 	int				error;
@@ -363,12 +361,13 @@ xfs_trans_free_extent(
 	if (xefi->xefi_flags & XFS_EFI_BMBT_BLOCK)
 		oinfo.oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;
 
-	trace_xfs_bmap_free_deferred(tp->t_mountp, agno, 0, agbno,
-			xefi->xefi_blockcount);
+	trace_xfs_bmap_free_deferred(tp->t_mountp, xefi->xefi_pag->pag_agno, 0,
+			agbno, xefi->xefi_blockcount);
 
-	error = __xfs_free_extent(tp, xefi->xefi_startblock,
+	error = __xfs_free_extent(tp, xefi->xefi_pag, agbno,
 			xefi->xefi_blockcount, &oinfo, XFS_AG_RESV_NONE,
 			xefi->xefi_flags & XFS_EFI_SKIP_DISCARD);
+
 	/*
 	 * Mark the transaction dirty, even on error. This ensures the
 	 * transaction is aborted, which:
@@ -396,14 +395,13 @@ xfs_extent_free_diff_items(
 	const struct list_head		*a,
 	const struct list_head		*b)
 {
-	struct xfs_mount		*mp = priv;
 	struct xfs_extent_free_item	*ra;
 	struct xfs_extent_free_item	*rb;
 
 	ra = container_of(a, struct xfs_extent_free_item, xefi_list);
 	rb = container_of(b, struct xfs_extent_free_item, xefi_list);
-	return  XFS_FSB_TO_AGNO(mp, ra->xefi_startblock) -
-		XFS_FSB_TO_AGNO(mp, rb->xefi_startblock);
+
+	return ra->xefi_pag->pag_agno - rb->xefi_pag->pag_agno;
 }
 
 /* Log a free extent to the intent item. */
@@ -462,6 +460,26 @@ xfs_extent_free_create_done(
 	return &xfs_trans_get_efd(tp, EFI_ITEM(intent), count)->efd_item;
 }
 
+/* Take a passive ref to the AG containing the space we're freeing. */
+void
+xfs_extent_free_get_group(
+	struct xfs_mount		*mp,
+	struct xfs_extent_free_item	*xefi)
+{
+	xfs_agnumber_t			agno;
+
+	agno = XFS_FSB_TO_AGNO(mp, xefi->xefi_startblock);
+	xefi->xefi_pag = xfs_perag_get(mp, agno);
+}
+
+/* Release a passive 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);
+}
+
 /* Process a free extent. */
 STATIC int
 xfs_extent_free_finish_item(
@@ -476,6 +494,8 @@ xfs_extent_free_finish_item(
 	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
 
 	error = xfs_trans_free_extent(tp, EFD_ITEM(done), xefi);
+
+	xfs_extent_free_put_group(xefi);
 	kmem_cache_free(xfs_extfree_item_cache, xefi);
 	return error;
 }
@@ -496,6 +516,8 @@ xfs_extent_free_cancel_item(
 	struct xfs_extent_free_item	*xefi;
 
 	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
+
+	xfs_extent_free_put_group(xefi);
 	kmem_cache_free(xfs_extfree_item_cache, xefi);
 }
 
@@ -526,24 +548,21 @@ xfs_agfl_free_finish_item(
 	struct xfs_extent		*extp;
 	struct xfs_buf			*agbp;
 	int				error;
-	xfs_agnumber_t			agno;
 	xfs_agblock_t			agbno;
 	uint				next_extent;
-	struct xfs_perag		*pag;
 
 	xefi = container_of(item, struct xfs_extent_free_item, xefi_list);
 	ASSERT(xefi->xefi_blockcount == 1);
-	agno = XFS_FSB_TO_AGNO(mp, xefi->xefi_startblock);
 	agbno = XFS_FSB_TO_AGBNO(mp, xefi->xefi_startblock);
 	oinfo.oi_owner = xefi->xefi_owner;
 
-	trace_xfs_agfl_free_deferred(mp, agno, 0, agbno, xefi->xefi_blockcount);
+	trace_xfs_agfl_free_deferred(mp, xefi->xefi_pag->pag_agno, 0, agbno,
+			xefi->xefi_blockcount);
 
-	pag = xfs_perag_get(mp, agno);
-	error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
+	error = xfs_alloc_read_agf(xefi->xefi_pag, tp, 0, &agbp);
 	if (!error)
-		error = xfs_free_agfl_block(tp, agno, agbno, agbp, &oinfo);
-	xfs_perag_put(pag);
+		error = xfs_free_agfl_block(tp, xefi->xefi_pag->pag_agno,
+				agbno, agbp, &oinfo);
 
 	/*
 	 * Mark the transaction dirty, even on error. This ensures the
@@ -562,6 +581,7 @@ xfs_agfl_free_finish_item(
 	extp->ext_len = xefi->xefi_blockcount;
 	efdp->efd_next_extent++;
 
+	xfs_extent_free_put_group(xefi);
 	kmem_cache_free(xfs_extfree_item_cache, xefi);
 	return error;
 }
@@ -632,7 +652,9 @@ xfs_efi_item_recover(
 		fake.xefi_startblock = extp->ext_start;
 		fake.xefi_blockcount = extp->ext_len;
 
+		xfs_extent_free_get_group(mp, &fake);
 		error = xfs_trans_free_extent(tp, efdp, &fake);
+		xfs_extent_free_put_group(&fake);
 		if (error == -EFSCORRUPTED)
 			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
 					extp, sizeof(*extp));