Commit 8620da16 authored by Mark Harmstone's avatar Mark Harmstone Committed by David Sterba
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btrfs: allow mounting filesystems with remap-tree incompat flag 



If we encounter a filesystem with the remap-tree incompat flag set,
validate its compatibility with the other flags, and load the remap tree
using the values that have been added to the superblock.

The remap-tree feature depends on the free-space-tree, but no-holes and
block-group-tree have been made dependencies to reduce the testing
matrix. Similarly I'm not aware of any reason why mixed-bg and zoned would be
incompatible with remap-tree, but this is blocked for the time being
until it can be fully tested.

Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarMark Harmstone <mark@harmstone.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 79770114

fs/btrfs/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -116,4 +116,6 @@ config BTRFS_EXPERIMENTAL 


	  - asynchronous checksum generation for data writes



	  - remap-tree - logical address remapping tree



	  If unsure, say N.

fs/btrfs/accessors.h

+6 −0
Original line number Diff line number Diff line
@@ -883,6 +883,12 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block, 
			 uuid_tree_generation, 64);

BTRFS_SETGET_STACK_FUNCS(super_nr_global_roots, struct btrfs_super_block,

			 nr_global_roots, 64);

BTRFS_SETGET_STACK_FUNCS(super_remap_root, struct btrfs_super_block,

			 remap_root, 64);

BTRFS_SETGET_STACK_FUNCS(super_remap_root_generation, struct btrfs_super_block,

			 remap_root_generation, 64);

BTRFS_SETGET_STACK_FUNCS(super_remap_root_level, struct btrfs_super_block,

			 remap_root_level, 8);



/* struct btrfs_file_extent_item */

BTRFS_SETGET_STACK_FUNCS(stack_file_extent_type, struct btrfs_file_extent_item,

fs/btrfs/disk-io.c

+92 −13
Original line number Diff line number Diff line
@@ -1136,6 +1136,8 @@ static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info, 
		return btrfs_grab_root(btrfs_global_root(fs_info, &key));

	case BTRFS_RAID_STRIPE_TREE_OBJECTID:

		return btrfs_grab_root(fs_info->stripe_root);

	case BTRFS_REMAP_TREE_OBJECTID:

		return btrfs_grab_root(fs_info->remap_root);

	default:

		return NULL;

	}
@@ -1226,6 +1228,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info) 
	btrfs_put_root(fs_info->data_reloc_root);

	btrfs_put_root(fs_info->block_group_root);

	btrfs_put_root(fs_info->stripe_root);

	btrfs_put_root(fs_info->remap_root);

	btrfs_check_leaked_roots(fs_info);

	btrfs_extent_buffer_leak_debug_check(fs_info);

	kfree(fs_info->super_copy);
@@ -1778,6 +1781,7 @@ static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root) 
	free_root_extent_buffers(info->data_reloc_root);

	free_root_extent_buffers(info->block_group_root);

	free_root_extent_buffers(info->stripe_root);

	free_root_extent_buffers(info->remap_root);

	if (free_chunk_root)

		free_root_extent_buffers(info->chunk_root);

}
@@ -2191,9 +2195,31 @@ static int btrfs_read_roots(struct btrfs_fs_info *fs_info) 
	if (ret)

		goto out;



	if (btrfs_fs_incompat(fs_info, REMAP_TREE)) {

		/* The remap_root has already been loaded in load_important_roots(). */

		root = fs_info->remap_root;



		set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);



		root->root_key.objectid = BTRFS_REMAP_TREE_OBJECTID;

		root->root_key.type = BTRFS_ROOT_ITEM_KEY;

		root->root_key.offset = 0;



		/* Check that data reloc tree doesn't also exist. */

		location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID;

		root = btrfs_read_tree_root(fs_info->tree_root, &location);

		if (!IS_ERR(root)) {

			btrfs_err(fs_info, "data reloc tree exists when remap-tree enabled");

			btrfs_put_root(root);

			return -EIO;

		} else if (PTR_ERR(root) != -ENOENT) {

			btrfs_warn(fs_info, "error %ld when checking for data reloc tree",

				   PTR_ERR(root));

		}

	} else {

		/*

	 * This tree can share blocks with some other fs tree during relocation

	 * and we need a proper setup by btrfs_get_fs_root

		 * This tree can share blocks with some other fs tree during

		 * relocation and we need a proper setup by btrfs_get_fs_root().

		 */

		root = btrfs_get_fs_root(tree_root->fs_info,

					 BTRFS_DATA_RELOC_TREE_OBJECTID, true);
@@ -2207,6 +2233,7 @@ static int btrfs_read_roots(struct btrfs_fs_info *fs_info) 
			set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);

			fs_info->data_reloc_root = root;

		}

	}



	location.objectid = BTRFS_QUOTA_TREE_OBJECTID;

	root = btrfs_read_tree_root(tree_root, &location);
@@ -2445,6 +2472,35 @@ int btrfs_validate_super(const struct btrfs_fs_info *fs_info, 
		ret = -EINVAL;

	}



	if (btrfs_fs_incompat(fs_info, REMAP_TREE)) {

		/*

		 * Reduce test matrix for remap tree by requiring block-group-tree

		 * and no-holes. Free-space-tree is a hard requirement.

		 */

		if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID) ||

		    !btrfs_fs_incompat(fs_info, NO_HOLES) ||

		    !btrfs_fs_compat_ro(fs_info, BLOCK_GROUP_TREE)) {

			btrfs_err(fs_info,

"remap-tree feature requires free-space-tree, no-holes, and block-group-tree");

			ret = -EINVAL;

		}



		if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {

			btrfs_err(fs_info, "remap-tree not supported with mixed-bg");

			ret = -EINVAL;

		}



		if (btrfs_fs_incompat(fs_info, ZONED)) {

			btrfs_err(fs_info, "remap-tree not supported with zoned devices");

			ret = -EINVAL;

		}



		if (sectorsize > PAGE_SIZE) {

			btrfs_err(fs_info, "remap-tree not supported when block size > page size");

			ret = -EINVAL;

		}

	}



	/*

	 * Hint to catch really bogus numbers, bitflips or so, more exact checks are

	 * done later
@@ -2603,6 +2659,18 @@ static int load_important_roots(struct btrfs_fs_info *fs_info) 
		btrfs_warn(fs_info, "couldn't read tree root");

		return ret;

	}



	if (btrfs_fs_incompat(fs_info, REMAP_TREE)) {

		bytenr = btrfs_super_remap_root(sb);

		gen = btrfs_super_remap_root_generation(sb);

		level = btrfs_super_remap_root_level(sb);

		ret = load_super_root(fs_info->remap_root, bytenr, gen, level);

		if (ret) {

			btrfs_warn(fs_info, "couldn't read remap root");

			return ret;

		}

	}



	return 0;

}
@@ -3231,6 +3299,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	struct btrfs_fs_info *fs_info = btrfs_sb(sb);

	struct btrfs_root *tree_root;

	struct btrfs_root *chunk_root;

	struct btrfs_root *remap_root;

	int ret;

	int level;
@@ -3365,6 +3434,16 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 
	if (ret < 0)

		goto fail_alloc;



	if (btrfs_super_incompat_flags(disk_super) & BTRFS_FEATURE_INCOMPAT_REMAP_TREE) {

		remap_root = btrfs_alloc_root(fs_info, BTRFS_REMAP_TREE_OBJECTID,

					      GFP_KERNEL);

		fs_info->remap_root = remap_root;

		if (!remap_root) {

			ret = -ENOMEM;

			goto fail_alloc;

		}

	}



	/*

	 * At this point our mount options are validated, if we set ->max_inline

	 * to something non-standard make sure we truncate it to sectorsize.

fs/btrfs/extent-tree.c

+2 −0
Original line number Diff line number Diff line
@@ -2593,6 +2593,8 @@ static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data) 
		flags = BTRFS_BLOCK_GROUP_DATA;

	else if (root == fs_info->chunk_root)

		flags = BTRFS_BLOCK_GROUP_SYSTEM;

	else if (root == fs_info->remap_root)

		flags = BTRFS_BLOCK_GROUP_METADATA_REMAP;

	else

		flags = BTRFS_BLOCK_GROUP_METADATA;

fs/btrfs/fs.h

+3 −1
Original line number Diff line number Diff line
@@ -315,7 +315,8 @@ enum { 
#define BTRFS_FEATURE_INCOMPAT_SUPP		\

	(BTRFS_FEATURE_INCOMPAT_SUPP_STABLE |	\

	 BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE | \

	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)

	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 | \

	 BTRFS_FEATURE_INCOMPAT_REMAP_TREE)



#else
@@ -475,6 +476,7 @@ struct btrfs_fs_info { 
	struct btrfs_root *data_reloc_root;

	struct btrfs_root *block_group_root;

	struct btrfs_root *stripe_root;

	struct btrfs_root *remap_root;



	/* The log root tree is a directory of all the other log roots */

	struct btrfs_root *log_root_tree;