From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Tue, 25 Oct 2016 01:26:48 +0000 (+1100)
Subject: xfs: adjust refcount when unmapping file blocks
X-Git-Tag: v4.9.0-rc1~102
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cfe32f0db83c38696cf1a820ddc93444f33ddf97;p=thirdparty%2Fxfsprogs-dev.git

xfs: adjust refcount when unmapping file blocks

Source kernel commit: 62aab20f08758b1b171a73a54e0c72dd12beb980

When we're unmapping blocks from a reflinked file, decrease the
refcount of the affected blocks and free the extents that are no
longer in use.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 0a8edeb4b..a97024d64 100644
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -122,6 +122,11 @@ xfs_set_projid(struct xfs_icdinode *id, prid_t projid)
 	id->di_projid_lo = (__uint16_t) (projid & 0xffff);
 }
 
+static inline bool xfs_is_reflink_inode(struct xfs_inode *ip)
+{
+	return ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
+}
+
 typedef struct cred {
 	uid_t	cr_uid;
 	gid_t	cr_gid;
diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index bd1d2d9d8..9a911e848 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -40,6 +40,7 @@
 #include "xfs_quota_defs.h"
 #include "xfs_rmap.h"
 #include "xfs_ag_resv.h"
+#include "xfs_refcount.h"
 
 
 kmem_zone_t		*xfs_bmap_free_item_zone;
@@ -4980,9 +4981,16 @@ xfs_bmap_del_extent(
 	/*
 	 * If we need to, add to list of extents to delete.
 	 */
-	if (do_fx)
-		xfs_bmap_add_free(mp, dfops, del->br_startblock,
-				del->br_blockcount, NULL);
+	if (do_fx) {
+		if (xfs_is_reflink_inode(ip) && whichfork == XFS_DATA_FORK) {
+			error = xfs_refcount_decrease_extent(mp, dfops, del);
+			if (error)
+				goto done;
+		} else
+			xfs_bmap_add_free(mp, dfops, del->br_startblock,
+					del->br_blockcount, NULL);
+	}
+
 	/*
 	 * Adjust inode # blocks in the file.
 	 */