btrfs: add code to support the block group root

This code adds the on disk structures for the block group root, which
will hold the block group items for extent tree v2.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 54424b34113237c7e6df0f106f5d13013ce82805..f460a7bb9ae8f860f867217ad1c0886a7ab8022a 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -274,8 +274,14 @@ struct btrfs_super_block {
        /* the UUID written into btree blocks */
        u8 metadata_uuid[BTRFS_FSID_SIZE];
 
+       /* Extent tree v2 */
+       __le64 block_group_root;
+       __le64 block_group_root_generation;
+       u8 block_group_root_level;
+
        /* future expansion */
-       __le64 reserved[28];
+       u8 reserved8[7];
+       __le64 reserved[25];
        u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
        struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
 
@@ -657,6 +663,7 @@ struct btrfs_fs_info {
        struct btrfs_root *quota_root;
        struct btrfs_root *uuid_root;
        struct btrfs_root *data_reloc_root;
+       struct btrfs_root *block_group_root;
 
        /* the log root tree is a directory of all the other log roots */
        struct btrfs_root *log_root_tree;
@@ -2349,6 +2356,17 @@ BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
 BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
                   num_devices, 64);
 
+/*
+ * For extent tree v2 we overload the extent root with the block group root, as
+ * we will have multiple extent roots.
+ */
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root, struct btrfs_root_backup,
+                        extent_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_gen, struct btrfs_root_backup,
+                        extent_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_level,
+                        struct btrfs_root_backup, extent_root_level, 8);
+
 /* struct btrfs_balance_item */
 BTRFS_SETGET_FUNCS(balance_flags, struct btrfs_balance_item, flags, 64);
 
@@ -2483,6 +2501,13 @@ BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
 BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
 BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
                         uuid_tree_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root, struct btrfs_super_block,
+                        block_group_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_generation,
+                        struct btrfs_super_block,
+                        block_group_root_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_level, struct btrfs_super_block,
+                        block_group_root_level, 8);
 
 int btrfs_super_csum_size(const struct btrfs_super_block *s);
 const char *btrfs_super_csum_name(u16 csum_type);

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e014cb8413c7b06d7a1fc80fafb14752c47a0f23..fe1349737edbcdcdf868ec9232cf86d4ba4db0c1 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1727,6 +1727,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
        btrfs_put_root(fs_info->uuid_root);
        btrfs_put_root(fs_info->fs_root);
        btrfs_put_root(fs_info->data_reloc_root);
+       btrfs_put_root(fs_info->block_group_root);
        btrfs_check_leaked_roots(fs_info);
        btrfs_extent_buffer_leak_debug_check(fs_info);
        kfree(fs_info->super_copy);
@@ -2095,7 +2096,6 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 {
        const int next_backup = info->backup_root_index;
        struct btrfs_root_backup *root_backup;
-       struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
        struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
 
        root_backup = info->super_for_commit->super_roots + next_backup;
@@ -2121,11 +2121,23 @@ static void backup_super_roots(struct btrfs_fs_info *info)
        btrfs_set_backup_chunk_root_level(root_backup,
                               btrfs_header_level(info->chunk_root->node));
 
-       btrfs_set_backup_extent_root(root_backup, extent_root->node->start);
-       btrfs_set_backup_extent_root_gen(root_backup,
-                              btrfs_header_generation(extent_root->node));
-       btrfs_set_backup_extent_root_level(root_backup,
-                              btrfs_header_level(extent_root->node));
+       if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
+               btrfs_set_backup_block_group_root(root_backup,
+                                       info->block_group_root->node->start);
+               btrfs_set_backup_block_group_root_gen(root_backup,
+                       btrfs_header_generation(info->block_group_root->node));
+               btrfs_set_backup_block_group_root_level(root_backup,
+                       btrfs_header_level(info->block_group_root->node));
+       } else {
+               struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
+
+               btrfs_set_backup_extent_root(root_backup,
+                                            extent_root->node->start);
+               btrfs_set_backup_extent_root_gen(root_backup,
+                               btrfs_header_generation(extent_root->node));
+               btrfs_set_backup_extent_root_level(root_backup,
+                                       btrfs_header_level(extent_root->node));
+       }
 
        /*
         * we might commit during log recovery, which happens before we set
@@ -2269,6 +2281,7 @@ static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
        free_root_extent_buffers(info->uuid_root);
        free_root_extent_buffers(info->fs_root);
        free_root_extent_buffers(info->data_reloc_root);
+       free_root_extent_buffers(info->block_group_root);
        if (free_chunk_root)
                free_root_extent_buffers(info->chunk_root);
 }
@@ -2964,8 +2977,20 @@ static int load_important_roots(struct btrfs_fs_info *fs_info)
        gen = btrfs_super_generation(sb);
        level = btrfs_super_root_level(sb);
        ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
-       if (ret)
+       if (ret) {
                btrfs_warn(fs_info, "couldn't read tree root");
+               return ret;
+       }
+
+       if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+               return 0;
+
+       bytenr = btrfs_super_block_group_root(sb);
+       gen = btrfs_super_block_group_root_generation(sb);
+       level = btrfs_super_block_group_root_level(sb);
+       ret = load_super_root(fs_info->block_group_root, bytenr, gen, level);
+       if (ret)
+               btrfs_warn(fs_info, "couldn't read block group root");
        return ret;
 }
 
@@ -2978,6 +3003,16 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
        int ret = 0;
        int i;
 
+       if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+               struct btrfs_root *root;
+
+               root = btrfs_alloc_root(fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID,
+                                       GFP_KERNEL);
+               if (!root)
+                       return -ENOMEM;
+               fs_info->block_group_root = root;
+       }
+
        for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
                if (handle_error) {
                        if (!IS_ERR(tree_root->node))

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 5e8bef4b7563a7c676165487e73a04550591f389..2e10514ecda857933527886017018176b37c3c08 100644 (file)
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -111,6 +111,8 @@ static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
 
 static inline struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info)
 {
+       if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+               return fs_info->block_group_root;
        return btrfs_extent_root(fs_info, 0);
 }
 

diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index 0775ae9f4419226255142f8c95eec93b5c9389dd..524fdb0ddd74b7f6fe185b5c5476e567570d1599 100644 (file)
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -23,6 +23,7 @@ static const struct root_name_map root_map[] = {
        { BTRFS_QUOTA_TREE_OBJECTID,            "QUOTA_TREE"            },
        { BTRFS_UUID_TREE_OBJECTID,             "UUID_TREE"             },
        { BTRFS_FREE_SPACE_TREE_OBJECTID,       "FREE_SPACE_TREE"       },
+       { BTRFS_BLOCK_GROUP_TREE_OBJECTID,      "BLOCK_GROUP_TREE"      },
        { BTRFS_DATA_RELOC_TREE_OBJECTID,       "DATA_RELOC_TREE"       },
 };
 

diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 0d729664b4b41fa3033e506560a437533f612d00..f068ff30d6541fe835a614ae2d7fbd08ba8a276d 100644 (file)
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -53,6 +53,7 @@ struct btrfs_space_info;
                { BTRFS_TREE_RELOC_OBJECTID,    "TREE_RELOC"    },      \
                { BTRFS_UUID_TREE_OBJECTID,     "UUID_TREE"     },      \
                { BTRFS_FREE_SPACE_TREE_OBJECTID, "FREE_SPACE_TREE" },  \
+               { BTRFS_BLOCK_GROUP_TREE_OBJECTID, "BLOCK_GROUP_TREE" },\
                { BTRFS_DATA_RELOC_TREE_OBJECTID, "DATA_RELOC_TREE" })
 
 #define show_root_type(obj)                                            \

diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index 5416f1f1a77a859bdd444461a325788385f081e9..b069752a8ecfd07e74ce6d1f901e93b16112d7a1 100644 (file)
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -53,6 +53,9 @@
 /* tracks free space in block groups. */
 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
 
+/* Holds the block group items for extent tree v2. */
+#define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL
+
 /* device stats in the device tree */
 #define BTRFS_DEV_STATS_OBJECTID 0ULL