btrfs: introduce chunk allocation policy

Introduce chunk allocation policy for btrfs. This policy controls how
chunks and device extents are allocated from devices.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f1c98b0..e4a2d96 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1205,6 +1205,7 @@ static int open_fs_devices(struct btrfs_fs_devices *fs_devices,
        fs_devices->opened = 1;
        fs_devices->latest_bdev = latest_dev->bdev;
        fs_devices->total_rw_bytes = 0;
+       fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR;
 out:
        return ret;
 }

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7b657f2..f067b59 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -207,6 +207,10 @@ BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
 BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
 BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
 
+enum btrfs_chunk_allocation_policy {
+       BTRFS_CHUNK_ALLOC_REGULAR,
+};
+
 struct btrfs_fs_devices {
        u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
        u8 metadata_uuid[BTRFS_FSID_SIZE];
@@ -258,6 +262,8 @@ struct btrfs_fs_devices {
        struct kobject *devices_kobj;
        struct kobject *devinfo_kobj;
        struct completion kobj_unregister;
+
+       enum btrfs_chunk_allocation_policy chunk_alloc_policy;
 };
 
 #define BTRFS_BIO_INLINE_CSUM_SIZE     64