[PATCH 17/26] xfs: hoist xfs_{bump,drop}link to libxfs

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Move xfs_bumplink and xfs_droplink to libxfs.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 include/xfs_inode.h     |    4 ++++
 libxfs/xfs_inode_util.c |   35 +++++++++++++++++++++++++++++++++++
 libxfs/xfs_inode_util.h |    2 ++
 3 files changed, 41 insertions(+)


diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 234f8d3affa..ccd19e5ee5b 100644
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -257,6 +257,10 @@ static inline void inc_nlink(struct inode *inode)
 {
 	inode->i_nlink++;
 }
+static inline void drop_nlink(struct inode *inode)
+{
+	inode->i_nlink--;
+}
 
 static inline bool xfs_is_reflink_inode(struct xfs_inode *ip)
 {
diff --git a/libxfs/xfs_inode_util.c b/libxfs/xfs_inode_util.c
index 4b19edd9ab1..e12c43954cf 100644
--- a/libxfs/xfs_inode_util.c
+++ b/libxfs/xfs_inode_util.c
@@ -608,3 +608,38 @@ xfs_iunlink_remove(
 
 	return xfs_iunlink_remove_inode(tp, pag, agibp, ip);
 }
+
+/*
+ * Decrement the link count on an inode & log the change.  If this causes the
+ * link count to go to zero, move the inode to AGI unlinked list so that it can
+ * be freed when the last active reference goes away via xfs_inactive().
+ */
+int
+xfs_droplink(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip)
+{
+	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
+
+	drop_nlink(VFS_I(ip));
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+	if (VFS_I(ip)->i_nlink)
+		return 0;
+
+	return xfs_iunlink(tp, ip);
+}
+
+/*
+ * Increment the link count on an inode & log the change.
+ */
+void
+xfs_bumplink(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip)
+{
+	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
+
+	inc_nlink(VFS_I(ip));
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+}
diff --git a/libxfs/xfs_inode_util.h b/libxfs/xfs_inode_util.h
index e15cf94e094..f92b14a6fbe 100644
--- a/libxfs/xfs_inode_util.h
+++ b/libxfs/xfs_inode_util.h
@@ -59,6 +59,8 @@ void xfs_inode_init(struct xfs_trans *tp, const struct xfs_icreate_args *args,
 int xfs_iunlink(struct xfs_trans *tp, struct xfs_inode *ip);
 int xfs_iunlink_remove(struct xfs_trans *tp, struct xfs_perag *pag,
 		struct xfs_inode *ip);
+int xfs_droplink(struct xfs_trans *tp, struct xfs_inode *ip);
+void xfs_bumplink(struct xfs_trans *tp, struct xfs_inode *ip);
 
 /* The libxfs client must provide this group of helper functions. */