Btrfs: Add support for mirroring across drives

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

1 files changed, 49 insertions, 44 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a34c289aec21..4ab98d8b73fa 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -230,9 +230,13 @@ again:
                         goto new_group;
                 if (start + num  > total_fs_bytes)
                         goto new_group;
+                if (!block_group_bits(cache, data)) {
+                        printk("block group bits don't match %Lu %Lu\n", cache->flags, data);
+                }
                 *start_ret = start;
                 return 0;
-        } out:
+        }
+out:
         cache = btrfs_lookup_block_group(root->fs_info, search_start);
         if (!cache) {
                 printk("Unable to find block group for %Lu\n", search_start);
@@ -365,14 +369,17 @@ again:
                 if (cache->key.objectid > total_fs_bytes)
                         break;
 
-                if (full_search)
-                        free_check = cache->key.offset;
-                else
-                        free_check = div_factor(cache->key.offset, factor);
+                if (block_group_bits(cache, data)) {
+                        if (full_search)
+                                free_check = cache->key.offset;
+                        else
+                                free_check = div_factor(cache->key.offset,
+                                                        factor);
 
-                if (used + cache->pinned < free_check) {
-                        found_group = cache;
-                        goto found;
+                        if (used + cache->pinned < free_check) {
+                                found_group = cache;
+                                goto found;
+                        }
                 }
                 cond_resched();
         }
@@ -1038,6 +1045,19 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
         return 0;
 }
 
+static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
+{
+        u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
+                                   BTRFS_BLOCK_GROUP_RAID1);
+        if (extra_flags) {
+                if (flags & BTRFS_BLOCK_GROUP_DATA)
+                        fs_info->avail_data_alloc_bits |= extra_flags;
+                if (flags & BTRFS_BLOCK_GROUP_METADATA)
+                        fs_info->avail_metadata_alloc_bits |= extra_flags;
+                if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+                        fs_info->avail_system_alloc_bits |= extra_flags;
+        }
+}
 
 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
                           struct btrfs_root *extent_root, u64 alloc_bytes,
@@ -1060,7 +1080,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
         if (space_info->full)
                 return 0;
 
-        thresh = div_factor(space_info->total_bytes, 7);
+        thresh = div_factor(space_info->total_bytes, 6);
         if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
             thresh)
                 return 0;
@@ -1079,16 +1099,7 @@ printk("space info full %Lu\n", flags);
                      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;
-                }
-        }
+        set_avail_alloc_bits(extent_root->fs_info, flags);
         return 0;
 }
 
@@ -1529,6 +1540,7 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
 
         if (data & BTRFS_BLOCK_GROUP_METADATA) {
                 last_ptr = &root->fs_info->last_alloc;
+                empty_cluster = 256 * 1024;
         }
 
         if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
@@ -1693,6 +1705,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         u64 root_used;
         u64 search_start = 0;
         u64 new_hint;
+        u64 alloc_profile;
         u32 sizes[2];
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_root *extent_root = info->extent_root;
@@ -1700,31 +1713,32 @@ 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 | info->extra_data_alloc_bits;
+                alloc_profile = info->avail_data_alloc_bits &
+                                info->data_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
         } else if (root == root->fs_info->chunk_root) {
-                data = BTRFS_BLOCK_GROUP_SYSTEM;
+                alloc_profile = info->avail_system_alloc_bits &
+                                info->system_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
         } else {
-                data = BTRFS_BLOCK_GROUP_METADATA | info->extra_alloc_bits;
+                alloc_profile = info->avail_metadata_alloc_bits &
+                                info->metadata_alloc_profile;
+                data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
         }
-        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)) {
                         ret = do_chunk_alloc(trans, root->fs_info->extent_root,
                                              2 * 1024 * 1024,
                                              BTRFS_BLOCK_GROUP_METADATA |
-                                             info->extra_alloc_bits |
-                                             extra_chunk_alloc_bits);
+                                             (info->metadata_alloc_profile &
+                                              info->avail_metadata_alloc_bits));
                         BUG_ON(ret);
                 }
                 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-                                     num_bytes + 2 * 1024 * 1024, data |
-                                     extra_chunk_alloc_bits);
+                                     num_bytes + 2 * 1024 * 1024, data);
                 BUG_ON(ret);
         }
 
@@ -2046,12 +2060,12 @@ static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
                 if (!next || !btrfs_buffer_uptodate(next)) {
                         free_extent_buffer(next);
                         reada_walk_down(root, cur, path->slots[*level]);
+
+                        mutex_unlock(&root->fs_info->fs_mutex);
                         next = read_tree_block(root, bytenr, blocksize);
+                        mutex_lock(&root->fs_info->fs_mutex);
 
-                        /* we used to drop the lock above, keep the
-                         * code to double check so that we won't forget
-                         * when we drop the lock again in the future
-                         */
+                        /* we've dropped the lock, double check */
                         ret = lookup_extent_ref(trans, root, bytenr,
                                                 blocksize, &refs);
                         BUG_ON(ret);
@@ -2739,16 +2753,7 @@ 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;
-                        }
-                }
+                set_avail_alloc_bits(info, cache->flags);
 
                 ret = update_space_info(info, cache->flags, found_key.offset,
                                         btrfs_block_group_used(&cache->item),