Commit f2b636e8 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

Btrfs: add support for compat flags to btrfs 



This adds the necessary disk format for handling compatibility flags
in the future to handle disk format changes.  We have a compat_flags,
compat_ro_flags and incompat_flags set for the super block.  Compat
flags will be to hold the features that are compatible with older
versions of btrfs, compat_ro flags have features that are compatible
with older versions of btrfs if the fs is mounted read only, and
incompat_flags has features that are incompatible with older versions
of btrfs.  This also axes the compat_flags field for the inode and
just makes the flags field a 64bit field, and changes the root item
flags field to 64bit.

Signed-off-by: default avatarJosef Bacik <jbacik@redhat.com>
parent 7a865e8a

fs/btrfs/ctree.h

+21 −7
Original line number Diff line number Diff line
@@ -305,6 +305,9 @@ struct btrfs_super_block { 
	__le32 stripesize;

	__le32 sys_chunk_array_size;

	__le64 chunk_root_generation;

	__le64 compat_flags;

	__le64 compat_ro_flags;

	__le64 incompat_flags;

	u8 root_level;

	u8 chunk_root_level;

	u8 log_root_level;
@@ -313,6 +316,14 @@ struct btrfs_super_block { 
	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];

} __attribute__ ((__packed__));



/*

 * Compat flags that we support.  If any incompat flags are set other than the

 * ones specified below then we will fail to mount

 */

#define BTRFS_FEATURE_COMPAT_SUPP	0x0

#define BTRFS_FEATURE_COMPAT_RO_SUPP	0x0

#define BTRFS_FEATURE_INCOMPAT_SUPP	0x0



/*

 * A leaf is full of items. offset and size tell us where to find

 * the item in the leaf (relative to the start of the data area)
@@ -433,8 +444,7 @@ struct btrfs_inode_item { 
	__le32 gid;

	__le32 mode;

	__le64 rdev;

	__le16 flags;

	__le16 compat_flags;

	__le64 flags;



	struct btrfs_timespec atime;

	struct btrfs_timespec ctime;
@@ -462,7 +472,7 @@ struct btrfs_root_item { 
	__le64 byte_limit;

	__le64 bytes_used;

	__le64 last_snapshot;

	__le32 flags;

	__le64 flags;

	__le32 refs;

	struct btrfs_disk_key drop_progress;

	u8 drop_level;
@@ -1116,9 +1126,7 @@ BTRFS_SETGET_FUNCS(inode_uid, struct btrfs_inode_item, uid, 32); 
BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32);

BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32);

BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64);

BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 16);

BTRFS_SETGET_FUNCS(inode_compat_flags, struct btrfs_inode_item,

		   compat_flags, 16);

BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64);



static inline struct btrfs_timespec *

btrfs_inode_atime(struct btrfs_inode_item *inode_item)
@@ -1468,7 +1476,7 @@ BTRFS_SETGET_STACK_FUNCS(root_bytenr, struct btrfs_root_item, bytenr, 64); 
BTRFS_SETGET_STACK_FUNCS(root_level, struct btrfs_root_item, level, 8);

BTRFS_SETGET_STACK_FUNCS(root_dirid, struct btrfs_root_item, root_dirid, 64);

BTRFS_SETGET_STACK_FUNCS(root_refs, struct btrfs_root_item, refs, 32);

BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 32);

BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 64);

BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64);

BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);

BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
@@ -1510,6 +1518,12 @@ BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block, 
			 root_dir_objectid, 64);

BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,

			 num_devices, 64);

BTRFS_SETGET_STACK_FUNCS(super_compat_flags, struct btrfs_super_block,

			 compat_flags, 64);

BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,

			 compat_flags, 64);

BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,

			 incompat_flags, 64);



static inline unsigned long btrfs_leaf_data(struct extent_buffer *l)

{

fs/btrfs/disk-io.c

+21 −0
Original line number Diff line number Diff line
@@ -1434,6 +1434,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	u32 blocksize;

	u32 stripesize;

	u64 generation;

	u64 features;

	struct btrfs_key location;

	struct buffer_head *bh;

	struct btrfs_root *extent_root = kzalloc(sizeof(struct btrfs_root),
@@ -1586,6 +1587,26 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
		goto fail_sb_buffer;

	}



	features = btrfs_super_incompat_flags(disk_super) &

		~BTRFS_FEATURE_INCOMPAT_SUPP;

	if (features) {

		printk(KERN_ERR "BTRFS: couldn't mount because of "

		       "unsupported optional features (%Lx).\n",

		       features);

		err = -EINVAL;

		goto fail_sb_buffer;

	}



	features = btrfs_super_compat_ro_flags(disk_super) &

		~BTRFS_FEATURE_COMPAT_RO_SUPP;

	if (!(sb->s_flags & MS_RDONLY) && features) {

		printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "

		       "unsupported option features (%Lx).\n",

		       features);

		err = -EINVAL;

		goto fail_sb_buffer;

	}



	/*

	 * we need to start all the end_io workers up front because the

	 * queue work function gets called at interrupt time, and so it

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