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, 23 insertions, 1 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0e410478ad27..76b82506bf92 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -45,6 +45,7 @@
 #include "inode-map.h"
 #include "check-integrity.h"
 #include "rcu-string.h"
+#include "dev-replace.h"
 
 #ifdef CONFIG_X86
 #include <asm/cpufeature.h>
@@ -2438,7 +2439,11 @@ int open_ctree(struct super_block *sb,
                 goto fail_tree_roots;
         }
 
-        btrfs_close_extra_devices(fs_devices);
+        /*
+         * keep the device that is marked to be the target device for the
+         * dev_replace procedure
+         */
+        btrfs_close_extra_devices(fs_info, fs_devices, 0);
 
         if (!fs_devices->latest_bdev) {
                 printk(KERN_CRIT "btrfs: failed to read devices on %s\n",
@@ -2510,6 +2515,14 @@ retry_root_backup:
                 goto fail_block_groups;
         }
 
+        ret = btrfs_init_dev_replace(fs_info);
+        if (ret) {
+                pr_err("btrfs: failed to init dev_replace: %d\n", ret);
+                goto fail_block_groups;
+        }
+
+        btrfs_close_extra_devices(fs_info, fs_devices, 1);
+
         ret = btrfs_init_space_info(fs_info);
         if (ret) {
                 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
@@ -2658,6 +2671,13 @@ retry_root_backup:
                 return ret;
         }
 
+        ret = btrfs_resume_dev_replace_async(fs_info);
+        if (ret) {
+                pr_warn("btrfs: failed to resume dev_replace\n");
+                close_ctree(tree_root);
+                return ret;
+        }
+
         return 0;
 
 fail_qgroup:
@@ -3300,6 +3320,8 @@ int close_ctree(struct btrfs_root *root)
         /* pause restriper - we want to resume on mount */
         btrfs_pause_balance(fs_info);
 
+        btrfs_dev_replace_suspend_for_unmount(fs_info);
+
         btrfs_scrub_cancel(fs_info);
 
         /* wait for any defraggers to finish */