[PATCH 43/71] xfs: cancel pending CoW reservations when destroying inodes

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

When destroying the inode, cancel all pending reservations in the CoW
fork so that all the reserved blocks go back to the free pile.  In
theory this sort of cleanup is only needed to clean up after write
errors.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/xfs_super.c |    8 ++++++++
 1 file changed, 8 insertions(+)


diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f62d50c..86afb15 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -49,6 +49,7 @@
 #include "xfs_rmap_item.h"
 #include "xfs_refcount_item.h"
 #include "xfs_bmap_item.h"
+#include "xfs_reflink.h"
 
 #include <linux/namei.h>
 #include <linux/init.h>
@@ -938,6 +939,7 @@ xfs_fs_destroy_inode(
        struct inode            *inode)
 {
        struct xfs_inode        *ip = XFS_I(inode);
+       int                     error;
 
        trace_xfs_destroy_inode(ip);
 
@@ -945,6 +947,12 @@ xfs_fs_destroy_inode(
        XFS_STATS_INC(ip->i_mount, vn_rele);
        XFS_STATS_INC(ip->i_mount, vn_remove);
 
+       error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
+       if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
+               xfs_warn(ip->i_mount, "Error %d while evicting CoW blocks "
+                               "for inode %llu.",
+                               error, ip->i_ino);
+
        xfs_inactive(ip);
 
        ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0);