[PATCH 1/5] xfs: refactor remote attr value buffer invalidation

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Hoist the code that invalidates remote extended attribute value buffers
into a separate helper function.  This prepares us for a memory
corruption fix in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_attr_remote.c |   44 +++++++++++++++++++++++++--------------
 fs/xfs/libxfs/xfs_attr_remote.h |    1 +
 2 files changed, 29 insertions(+), 16 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index a6ef5df42669..6babdaac6057 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -552,6 +552,32 @@ xfs_attr_rmtval_set(
 	return 0;
 }
 
+/* Mark stale any incore buffers for the remote value. */
+void
+xfs_attr_rmtval_stale(
+	struct xfs_inode	*ip,
+	struct xfs_bmbt_irec	*map)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_buf		*bp;
+	xfs_daddr_t		dblkno;
+	int			dblkcnt;
+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	dblkno = XFS_FSB_TO_DADDR(mp, map->br_startblock),
+	dblkcnt = XFS_FSB_TO_BB(mp, map->br_blockcount);
+
+	/*
+	 * If the "remote" value is in the cache, remove it.
+	 */
+	bp = xfs_buf_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
+	if (bp) {
+		xfs_buf_stale(bp);
+		xfs_buf_relse(bp);
+	}
+}
+
 /*
  * Remove the value associated with an attribute by deleting the
  * out-of-line buffer that it is stored on.
@@ -560,7 +586,6 @@ int
 xfs_attr_rmtval_remove(
 	struct xfs_da_args	*args)
 {
-	struct xfs_mount	*mp = args->dp->i_mount;
 	xfs_dablk_t		lblkno;
 	int			blkcnt;
 	int			error;
@@ -575,9 +600,6 @@ xfs_attr_rmtval_remove(
 	blkcnt = args->rmtblkcnt;
 	while (blkcnt > 0) {
 		struct xfs_bmbt_irec	map;
-		struct xfs_buf		*bp;
-		xfs_daddr_t		dblkno;
-		int			dblkcnt;
 		int			nmap;
 
 		/*
@@ -592,18 +614,8 @@ xfs_attr_rmtval_remove(
 		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
 		       (map.br_startblock != HOLESTARTBLOCK));
 
-		dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
-		dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
-
-		/*
-		 * If the "remote" value is in the cache, remove it.
-		 */
-		bp = xfs_buf_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK);
-		if (bp) {
-			xfs_buf_stale(bp);
-			xfs_buf_relse(bp);
-			bp = NULL;
-		}
+		if (map.br_startblock != HOLESTARTBLOCK)
+			xfs_attr_rmtval_stale(args->dp, &map);
 
 		lblkno += map.br_blockcount;
 		blkcnt -= map.br_blockcount;
diff --git a/fs/xfs/libxfs/xfs_attr_remote.h b/fs/xfs/libxfs/xfs_attr_remote.h
index 9d20b66ad379..ce7287ac5b1f 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.h
+++ b/fs/xfs/libxfs/xfs_attr_remote.h
@@ -11,5 +11,6 @@ int xfs_attr3_rmt_blocks(struct xfs_mount *mp, int attrlen);
 int xfs_attr_rmtval_get(struct xfs_da_args *args);
 int xfs_attr_rmtval_set(struct xfs_da_args *args);
 int xfs_attr_rmtval_remove(struct xfs_da_args *args);
+void xfs_attr_rmtval_stale(struct xfs_inode *ip, struct xfs_bmbt_irec *map);
 
 #endif /* __XFS_ATTR_REMOTE_H__ */