Btrfs: Implement raid0 when multiple devices are present

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 68 insertions, 34 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e9ef644ff56f..c226656f29b7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -172,7 +172,7 @@ struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
 
 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
 {
-        return (cache->flags & bits);
+        return (cache->flags & bits) == bits;
 }
 
 static int noinline find_search_start(struct btrfs_root *root,
@@ -1010,6 +1010,35 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
 
 }
 
+static int update_space_info(struct btrfs_fs_info *info, u64 flags,
+                             u64 total_bytes, u64 bytes_used,
+                             struct btrfs_space_info **space_info)
+{
+        struct btrfs_space_info *found;
+
+        found = __find_space_info(info, flags);
+        if (found) {
+                found->total_bytes += total_bytes;
+                found->bytes_used += bytes_used;
+                WARN_ON(found->total_bytes < found->bytes_used);
+                *space_info = found;
+                return 0;
+        }
+        found = kmalloc(sizeof(*found), GFP_NOFS);
+        if (!found)
+                return -ENOMEM;
+
+        list_add(&found->list, &info->space_info);
+        found->flags = flags;
+        found->total_bytes = total_bytes;
+        found->bytes_used = bytes_used;
+        found->bytes_pinned = 0;
+        found->full = 0;
+        *space_info = found;
+        return 0;
+}
+
+
 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
                           struct btrfs_root *extent_root, u64 alloc_bytes,
                           u64 flags)
@@ -1021,6 +1050,11 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
         int ret;
 
         space_info = __find_space_info(extent_root->fs_info, flags);
+        if (!space_info) {
+                ret = update_space_info(extent_root->fs_info, flags,
+                                        0, 0, &space_info);
+                BUG_ON(ret);
+        }
         BUG_ON(!space_info);
 
         if (space_info->full)
@@ -1044,6 +1078,17 @@ printk("space info full %Lu\n", flags);
                      extent_root->fs_info->chunk_root->root_key.objectid,
                      start, num_bytes);
         BUG_ON(ret);
+
+        if (flags & BTRFS_BLOCK_GROUP_RAID0) {
+                if (flags & BTRFS_BLOCK_GROUP_DATA) {
+                        extent_root->fs_info->extra_data_alloc_bits =
+                                BTRFS_BLOCK_GROUP_RAID0;
+                }
+                if (flags & BTRFS_BLOCK_GROUP_METADATA) {
+                        extent_root->fs_info->extra_alloc_bits =
+                                BTRFS_BLOCK_GROUP_RAID0;
+                }
+        }
         return 0;
 }
 
@@ -1655,24 +1700,31 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         struct btrfs_extent_ref *ref;
         struct btrfs_path *path;
         struct btrfs_key keys[2];
+        int extra_chunk_alloc_bits = 0;
 
         if (data) {
-                data = BTRFS_BLOCK_GROUP_DATA;
+                data = BTRFS_BLOCK_GROUP_DATA | info->extra_data_alloc_bits;
         } else if (root == root->fs_info->chunk_root) {
                 data = BTRFS_BLOCK_GROUP_SYSTEM;
         } else {
-                data = BTRFS_BLOCK_GROUP_METADATA;
+                data = BTRFS_BLOCK_GROUP_METADATA | info->extra_alloc_bits;
         }
+        if (btrfs_super_num_devices(&info->super_copy) > 1 &&
+            !(data & BTRFS_BLOCK_GROUP_SYSTEM))
+                extra_chunk_alloc_bits = BTRFS_BLOCK_GROUP_RAID0;
 
         if (root->ref_cows) {
-                if (data != BTRFS_BLOCK_GROUP_METADATA) {
+                if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
                         ret = do_chunk_alloc(trans, root->fs_info->extent_root,
                                              2 * 1024 * 1024,
-                                             BTRFS_BLOCK_GROUP_METADATA);
+                                             BTRFS_BLOCK_GROUP_METADATA |
+                                             info->extra_alloc_bits |
+                                             extra_chunk_alloc_bits);
                         BUG_ON(ret);
                 }
                 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-                                     num_bytes + 2 * 1024 * 1024, data);
+                                     num_bytes + 2 * 1024 * 1024, data |
+                                     extra_chunk_alloc_bits);
                 BUG_ON(ret);
         }
 
@@ -2627,34 +2679,6 @@ error:
         return ret;
 }
 
-static int update_space_info(struct btrfs_fs_info *info, u64 flags,
-                             u64 total_bytes, u64 bytes_used,
-                             struct btrfs_space_info **space_info)
-{
-        struct btrfs_space_info *found;
-
-        found = __find_space_info(info, flags);
-        if (found) {
-                found->total_bytes += total_bytes;
-                found->bytes_used += bytes_used;
-                WARN_ON(found->total_bytes < found->bytes_used);
-                *space_info = found;
-                return 0;
-        }
-        found = kmalloc(sizeof(*found), GFP_NOFS);
-        if (!found)
-                return -ENOMEM;
-
-        list_add(&found->list, &info->space_info);
-        found->flags = flags;
-        found->total_bytes = total_bytes;
-        found->bytes_used = bytes_used;
-        found->bytes_pinned = 0;
-        found->full = 0;
-        *space_info = found;
-        return 0;
-}
-
 int btrfs_read_block_groups(struct btrfs_root *root)
 {
         struct btrfs_path *path;
@@ -2712,6 +2736,16 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                 } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
                         bit = BLOCK_GROUP_METADATA;
                 }
+                if (cache->flags & BTRFS_BLOCK_GROUP_RAID0) {
+                        if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
+                                info->extra_data_alloc_bits =
+                                        BTRFS_BLOCK_GROUP_RAID0;
+                        }
+                        if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) {
+                                info->extra_alloc_bits =
+                                        BTRFS_BLOCK_GROUP_RAID0;
+                        }
+                }
 
                 ret = update_space_info(info, cache->flags, found_key.offset,
                                         btrfs_block_group_used(&cache->item),