Btrfs: make raid attr array more readable
authorMiao Xie <miaox@cn.fujitsu.com>
Thu, 17 Jan 2013 05:38:51 +0000 (05:38 +0000)
committerJosef Bacik <jbacik@fusionio.com>
Wed, 20 Feb 2013 14:37:19 +0000 (09:37 -0500)
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>
fs/btrfs/ctree.h
fs/btrfs/extent-tree.c
fs/btrfs/volumes.c

index 9ee099f3f8347003e753dc2aef4ab370ef5e6986..541ce9a9949e27e021ac72a35232903478f3cbd3 100644 (file)
@@ -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 |  \
index 82400b2b2517c5950832c0aa74c002918164b6ac..174c4d5c692c585c7a3f9a2b40148c375df91041 100644 (file)
@@ -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);
        }
index 5349e17d88639d0f1d861fe3ebb72ca3cd62ec6a..1ce581d58d8754000feb38896c5eca4c82c3a7e2 100644 (file)
@@ -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,