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/super.c b/fs/btrfs/super.c
index 442bf43..bfdaf12 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -312,10 +312,11 @@
Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
- Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
- Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
- Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
- Opt_check_integrity, Opt_check_integrity_including_extent_data,
+ Opt_space_cache, Opt_space_cache_version, Opt_clear_cache,
+ Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid,
+ Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery,
+ Opt_skip_balance, Opt_check_integrity,
+ Opt_check_integrity_including_extent_data,
Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
@@ -354,6 +355,7 @@
{Opt_discard, "discard"},
{Opt_nodiscard, "nodiscard"},
{Opt_space_cache, "space_cache"},
+ {Opt_space_cache_version, "space_cache=%s"},
{Opt_clear_cache, "clear_cache"},
{Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
{Opt_enospc_debug, "enospc_debug"},
@@ -392,7 +394,9 @@
bool compress_force = false;
cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
- if (cache_gen)
+ if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE))
+ btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
+ else if (cache_gen)
btrfs_set_opt(info->mount_opt, SPACE_CACHE);
if (!options)
@@ -626,15 +630,35 @@
"turning off discard");
break;
case Opt_space_cache:
- btrfs_set_and_info(root, SPACE_CACHE,
- "enabling disk space caching");
+ case Opt_space_cache_version:
+ if (token == Opt_space_cache ||
+ strcmp(args[0].from, "v1") == 0) {
+ btrfs_clear_opt(root->fs_info->mount_opt,
+ FREE_SPACE_TREE);
+ btrfs_set_and_info(root, SPACE_CACHE,
+ "enabling disk space caching");
+ } else if (strcmp(args[0].from, "v2") == 0) {
+ btrfs_clear_opt(root->fs_info->mount_opt,
+ SPACE_CACHE);
+ btrfs_set_and_info(root, FREE_SPACE_TREE,
+ "enabling free space tree");
+ } else {
+ ret = -EINVAL;
+ goto out;
+ }
break;
case Opt_rescan_uuid_tree:
btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
break;
case Opt_no_space_cache:
- btrfs_clear_and_info(root, SPACE_CACHE,
- "disabling disk space caching");
+ if (btrfs_test_opt(root, SPACE_CACHE)) {
+ btrfs_clear_and_info(root, SPACE_CACHE,
+ "disabling disk space caching");
+ }
+ if (btrfs_test_opt(root, FREE_SPACE_TREE)) {
+ btrfs_clear_and_info(root, FREE_SPACE_TREE,
+ "disabling free space tree");
+ }
break;
case Opt_inode_cache:
btrfs_set_pending_and_info(info, INODE_MAP_CACHE,
@@ -747,8 +771,17 @@
}
}
out:
+ if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE) &&
+ !btrfs_test_opt(root, FREE_SPACE_TREE) &&
+ !btrfs_test_opt(root, CLEAR_CACHE)) {
+ btrfs_err(root->fs_info, "cannot disable free space tree");
+ ret = -EINVAL;
+
+ }
if (!ret && btrfs_test_opt(root, SPACE_CACHE))
btrfs_info(root->fs_info, "disk space caching is enabled");
+ if (!ret && btrfs_test_opt(root, FREE_SPACE_TREE))
+ btrfs_info(root->fs_info, "using free space tree");
kfree(orig);
return ret;
}
@@ -1155,6 +1188,8 @@
seq_puts(seq, ",noacl");
if (btrfs_test_opt(root, SPACE_CACHE))
seq_puts(seq, ",space_cache");
+ else if (btrfs_test_opt(root, FREE_SPACE_TREE))
+ seq_puts(seq, ",space_cache=v2");
else
seq_puts(seq, ",nospace_cache");
if (btrfs_test_opt(root, RESCAN_UUID_TREE))