Btrfs: add free space tree mount option
Now we can finally hook up everything so we can actually use free space
tree. The free space tree is enabled by passing the space_cache=v2 mount
option. On the first mount with the this option set, the free space tree
will be created and the FREE_SPACE_TREE read-only compat bit will be
set. Any time the filesystem is mounted from then on, we must use the
free space tree. The clear_cache option will also clear the free space
tree.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1e60d00..af7ac28 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -42,6 +42,7 @@
#include "locking.h"
#include "tree-log.h"
#include "free-space-cache.h"
+#include "free-space-tree.h"
#include "inode-map.h"
#include "check-integrity.h"
#include "rcu-string.h"
@@ -1647,6 +1648,9 @@
if (location->objectid == BTRFS_UUID_TREE_OBJECTID)
return fs_info->uuid_root ? fs_info->uuid_root :
ERR_PTR(-ENOENT);
+ if (location->objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
+ return fs_info->free_space_root ? fs_info->free_space_root :
+ ERR_PTR(-ENOENT);
again:
root = btrfs_lookup_fs_root(fs_info, location->objectid);
if (root) {
@@ -2144,6 +2148,7 @@
free_root_extent_buffers(info->uuid_root);
if (chunk_root)
free_root_extent_buffers(info->chunk_root);
+ free_root_extent_buffers(info->free_space_root);
}
void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
@@ -2445,6 +2450,15 @@
fs_info->uuid_root = root;
}
+ if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
+ location.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
+ root = btrfs_read_tree_root(tree_root, &location);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+ set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
+ fs_info->free_space_root = root;
+ }
+
return 0;
}
@@ -3073,6 +3087,30 @@
btrfs_qgroup_rescan_resume(fs_info);
+ if (btrfs_test_opt(tree_root, CLEAR_CACHE) &&
+ btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
+ pr_info("BTRFS: clearing free space tree\n");
+ ret = btrfs_clear_free_space_tree(fs_info);
+ if (ret) {
+ pr_warn("BTRFS: failed to clear free space tree %d\n",
+ ret);
+ close_ctree(tree_root);
+ return ret;
+ }
+ }
+
+ if (btrfs_test_opt(tree_root, FREE_SPACE_TREE) &&
+ !btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
+ pr_info("BTRFS: creating free space tree\n");
+ ret = btrfs_create_free_space_tree(fs_info);
+ if (ret) {
+ pr_warn("BTRFS: failed to create free space tree %d\n",
+ ret);
+ close_ctree(tree_root);
+ return ret;
+ }
+ }
+
if (!fs_info->uuid_root) {
pr_info("BTRFS: creating UUID tree\n");
ret = btrfs_create_uuid_tree(fs_info);