Btrfs: enhance btrfs structures for device replace support

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

2 files changed, 44 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f8bb62c82b0c..0781fd4a5c1a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -885,6 +885,42 @@ struct btrfs_dev_stats_item {
         __le64 values[BTRFS_DEV_STAT_VALUES_MAX];
 } __attribute__ ((__packed__));
 
+#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS     0
+#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID      1
+#define BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED      0
+#define BTRFS_DEV_REPLACE_ITEM_STATE_STARTED            1
+#define BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED          2
+#define BTRFS_DEV_REPLACE_ITEM_STATE_FINISHED           3
+#define BTRFS_DEV_REPLACE_ITEM_STATE_CANCELED           4
+
+struct btrfs_dev_replace {
+        u64 replace_state;      /* see #define above */
+        u64 time_started;       /* seconds since 1-Jan-1970 */
+        u64 time_stopped;       /* seconds since 1-Jan-1970 */
+        atomic64_t num_write_errors;
+        atomic64_t num_uncorrectable_read_errors;
+
+        u64 cursor_left;
+        u64 committed_cursor_left;
+        u64 cursor_left_last_write_of_item;
+        u64 cursor_right;
+
+        u64 cont_reading_from_srcdev_mode;      /* see #define above */
+
+        int is_valid;
+        int item_needs_writeback;
+        struct btrfs_device *srcdev;
+        struct btrfs_device *tgtdev;
+
+        pid_t lock_owner;
+        atomic_t nesting_level;
+        struct mutex lock_finishing_cancel_unmount;
+        struct mutex lock_management_lock;
+        struct mutex lock;
+
+        struct btrfs_scrub_progress scrub_progress;
+};
+
 /* different types of block groups (and chunks) */
 #define BTRFS_BLOCK_GROUP_DATA          (1ULL << 0)
 #define BTRFS_BLOCK_GROUP_SYSTEM        (1ULL << 1)
@@ -1471,6 +1507,9 @@ struct btrfs_fs_info {
         int backup_root_index;
 
         int num_tolerated_disk_barrier_failures;
+
+        /* device replace state */
+        struct btrfs_dev_replace dev_replace;
 };
 
 /*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 42a8024e935f..9d1b71060813 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2131,6 +2131,11 @@ int open_ctree(struct super_block *sb,
         init_rwsem(&fs_info->extent_commit_sem);
         init_rwsem(&fs_info->cleanup_work_sem);
         init_rwsem(&fs_info->subvol_sem);
+        fs_info->dev_replace.lock_owner = 0;
+        atomic_set(&fs_info->dev_replace.nesting_level, 0);
+        mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount);
+        mutex_init(&fs_info->dev_replace.lock_management_lock);
+        mutex_init(&fs_info->dev_replace.lock);
 
         spin_lock_init(&fs_info->qgroup_lock);
         fs_info->qgroup_tree = RB_ROOT;