Btrfs: change core code of btrfs to support the device replace operations

This commit contains all the essential changes to the core code
of Btrfs for support of the device replace procedure.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index ad4380684b9b..def4f24b58df 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -55,6 +55,7 @@
 #include "export.h"
 #include "compression.h"
 #include "rcu-string.h"
+#include "dev-replace.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/btrfs.h>
@@ -1225,8 +1226,15 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
                 return 0;
 
         if (*flags & MS_RDONLY) {
+                /*
+                 * this also happens on 'umount -rf' or on shutdown, when
+                 * the filesystem is busy.
+                 */
                 sb->s_flags |= MS_RDONLY;
 
+                btrfs_dev_replace_suspend_for_unmount(fs_info);
+                btrfs_scrub_cancel(fs_info);
+
                 ret = btrfs_commit_super(root);
                 if (ret)
                         goto restore;
@@ -1263,6 +1271,11 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
                 if (ret)
                         goto restore;
 
+                ret = btrfs_resume_dev_replace_async(fs_info);
+                if (ret) {
+                        pr_warn("btrfs: failed to resume dev_replace\n");
+                        goto restore;
+                }
                 sb->s_flags &= ~MS_RDONLY;
         }