btrfs: use btrfs_raid_array in btrfs_reduce_alloc_profile

btrfs_raid_array[] holds attributes of all raid types.

Use btrfs_raid_array[].devs_min is best way for request
in btrfs_reduce_alloc_profile(), instead of use complex
condition of each raid types.

Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8a1759b..2b29800 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3822,7 +3822,8 @@ static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
 {
        u64 num_devices = root->fs_info->fs_devices->rw_devices;
        u64 target;
-       u64 tmp;
+       u64 raid_type;
+       u64 allowed = 0;
 
        /*
         * see if restripe for this chunk_type is in progress, if so
@@ -3840,31 +3841,26 @@ static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
        spin_unlock(&root->fs_info->balance_lock);
 
        /* First, mask out the RAID levels which aren't possible */
-       if (num_devices == 1)
-               flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
-                          BTRFS_BLOCK_GROUP_RAID5);
-       if (num_devices < 3)
-               flags &= ~BTRFS_BLOCK_GROUP_RAID6;
-       if (num_devices < 4)
-               flags &= ~BTRFS_BLOCK_GROUP_RAID10;
-
-       tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
-                      BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
-                      BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
-       flags &= ~tmp;
-
-       if (tmp & BTRFS_BLOCK_GROUP_RAID6)
-               tmp = BTRFS_BLOCK_GROUP_RAID6;
-       else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
-               tmp = BTRFS_BLOCK_GROUP_RAID5;
-       else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
-               tmp = BTRFS_BLOCK_GROUP_RAID10;
-       else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
-               tmp = BTRFS_BLOCK_GROUP_RAID1;
-       else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
-               tmp = BTRFS_BLOCK_GROUP_RAID0;
-
-       return extended_to_chunk(flags | tmp);
+       for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
+               if (num_devices >= btrfs_raid_array[raid_type].devs_min)
+                       allowed |= btrfs_raid_group[raid_type];
+       }
+       allowed &= flags;
+
+       if (allowed & BTRFS_BLOCK_GROUP_RAID6)
+               allowed = BTRFS_BLOCK_GROUP_RAID6;
+       else if (allowed & BTRFS_BLOCK_GROUP_RAID5)
+               allowed = BTRFS_BLOCK_GROUP_RAID5;
+       else if (allowed & BTRFS_BLOCK_GROUP_RAID10)
+               allowed = BTRFS_BLOCK_GROUP_RAID10;
+       else if (allowed & BTRFS_BLOCK_GROUP_RAID1)
+               allowed = BTRFS_BLOCK_GROUP_RAID1;
+       else if (allowed & BTRFS_BLOCK_GROUP_RAID0)
+               allowed = BTRFS_BLOCK_GROUP_RAID0;
+
+       flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
+
+       return extended_to_chunk(flags | allowed);
 }
 
 static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags)