Btrfs: make raid attr array more readable

The current code of raid attr arry is hard to understand and it is easy to
introduce some problem if we modify the array. So I changed it and made it
more readable.

Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9ee099f3f8347003e753dc2aef4ab370ef5e6986..541ce9a9949e27e021ac72a35232903478f3cbd3 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -953,7 +953,15 @@ struct btrfs_dev_replace_item {
 #define BTRFS_BLOCK_GROUP_DUP          (1ULL << 5)
 #define BTRFS_BLOCK_GROUP_RAID10       (1ULL << 6)
 #define BTRFS_BLOCK_GROUP_RESERVED     BTRFS_AVAIL_ALLOC_BIT_SINGLE
-#define BTRFS_NR_RAID_TYPES            5
+
+enum btrfs_raid_types {
+       BTRFS_RAID_RAID10,
+       BTRFS_RAID_RAID1,
+       BTRFS_RAID_DUP,
+       BTRFS_RAID_RAID0,
+       BTRFS_RAID_SINGLE,
+       BTRFS_NR_RAID_TYPES
+};
 
 #define BTRFS_BLOCK_GROUP_TYPE_MASK    (BTRFS_BLOCK_GROUP_DATA |    \
                                         BTRFS_BLOCK_GROUP_SYSTEM |  \

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 82400b2b2517c5950832c0aa74c002918164b6ac..174c4d5c692c585c7a3f9a2b40148c375df91041 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5545,20 +5545,16 @@ wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 
 int __get_raid_index(u64 flags)
 {
-       int index;
-
        if (flags & BTRFS_BLOCK_GROUP_RAID10)
-               index = 0;
+               return BTRFS_RAID_RAID10;
        else if (flags & BTRFS_BLOCK_GROUP_RAID1)
-               index = 1;
+               return BTRFS_RAID_RAID1;
        else if (flags & BTRFS_BLOCK_GROUP_DUP)
-               index = 2;
+               return BTRFS_RAID_DUP;
        else if (flags & BTRFS_BLOCK_GROUP_RAID0)
-               index = 3;
+               return BTRFS_RAID_RAID0;
        else
-               index = 4;
-
-       return index;
+               return BTRFS_RAID_SINGLE;
 }
 
 static int get_block_group_index(struct btrfs_block_group_cache *cache)
@@ -7518,16 +7514,16 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
                index = get_block_group_index(block_group);
        }
 
-       if (index == 0) {
+       if (index == BTRFS_RAID_RAID10) {
                dev_min = 4;
                /* Divide by 2 */
                min_free >>= 1;
-       } else if (index == 1) {
+       } else if (index == BTRFS_RAID_RAID1) {
                dev_min = 2;
-       } else if (index == 2) {
+       } else if (index == BTRFS_RAID_DUP) {
                /* Multiply by 2 */
                min_free <<= 1;
-       } else if (index == 3) {
+       } else if (index == BTRFS_RAID_RAID0) {
                dev_min = fs_devices->rw_devices;
                do_div(min_free, dev_min);
        }

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5349e17d88639d0f1d861fe3ebb72ca3cd62ec6a..1ce581d58d8754000feb38896c5eca4c82c3a7e2 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3562,13 +3562,48 @@ static int btrfs_cmp_device_info(const void *a, const void *b)
 }
 
 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
-       { 2, 1, 0, 4, 2, 2 /* raid10 */ },
-       { 1, 1, 2, 2, 2, 2 /* raid1 */ },
-       { 1, 2, 1, 1, 1, 2 /* dup */ },
-       { 1, 1, 0, 2, 1, 1 /* raid0 */ },
-       { 1, 1, 1, 1, 1, 1 /* single */ },
+       [BTRFS_RAID_RAID10] = {
+               .sub_stripes    = 2,
+               .dev_stripes    = 1,
+               .devs_max       = 0,    /* 0 == as many as possible */
+               .devs_min       = 4,
+               .devs_increment = 2,
+               .ncopies        = 2,
+       },
+       [BTRFS_RAID_RAID1] = {
+               .sub_stripes    = 1,
+               .dev_stripes    = 1,
+               .devs_max       = 2,
+               .devs_min       = 2,
+               .devs_increment = 2,
+               .ncopies        = 2,
+       },
+       [BTRFS_RAID_DUP] = {
+               .sub_stripes    = 1,
+               .dev_stripes    = 2,
+               .devs_max       = 1,
+               .devs_min       = 1,
+               .devs_increment = 1,
+               .ncopies        = 2,
+       },
+       [BTRFS_RAID_RAID0] = {
+               .sub_stripes    = 1,
+               .dev_stripes    = 1,
+               .devs_max       = 0,
+               .devs_min       = 2,
+               .devs_increment = 1,
+               .ncopies        = 1,
+       },
+       [BTRFS_RAID_SINGLE] = {
+               .sub_stripes    = 1,
+               .dev_stripes    = 1,
+               .devs_max       = 1,
+               .devs_min       = 1,
+               .devs_increment = 1,
+               .ncopies        = 1,
+       },
 };
-
+ 
 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                               struct btrfs_root *extent_root,
                               struct map_lookup **map_ret,