Commit 035e00ac authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Dave Chinner
Browse files

xfs: define the on-disk rmap btree format 



Originally-From: Dave Chinner <dchinner@redhat.com>

Now we have all the surrounding call infrastructure in place, we can
start filling out the rmap btree implementation. Start with the
on-disk btree format; add everything needed to read, write and
manipulate rmap btree blocks. This prepares the way for adding the
btree operations implementation.

[darrick: record owner and offset info in rmap btree]
[darrick: fork, bmbt and unwritten state in rmap btree]
[darrick: flags are a separate field in xfs_rmap_irec]
[darrick: calculate maxlevels separately]
[darrick: move the 'unwritten' bit into unused parts of rm_offset]

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 673930c3

fs/xfs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ xfs-y += $(addprefix libxfs/, \ 
				   xfs_inode_buf.o \

				   xfs_log_rlimit.o \

				   xfs_rmap.o \

				   xfs_rmap_btree.o \

				   xfs_sb.o \

				   xfs_symlink_remote.o \

				   xfs_trans_resv.o \

fs/xfs/libxfs/xfs_btree.c

+3 −0
Original line number Diff line number Diff line
@@ -1213,6 +1213,9 @@ xfs_btree_set_refs( 
	case XFS_BTNUM_BMAP:

		xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);

		break;

	case XFS_BTNUM_RMAP:

		xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);

		break;

	default:

		ASSERT(0);

	}

fs/xfs/libxfs/xfs_btree.h

+14 −8
Original line number Diff line number Diff line
@@ -38,10 +38,11 @@ union xfs_btree_ptr { 
};



union xfs_btree_key {

	xfs_bmbt_key_t		bmbt;

	struct xfs_bmbt_key		bmbt;

	xfs_bmdr_key_t			bmbr;	/* bmbt root block */

	xfs_alloc_key_t			alloc;

	xfs_inobt_key_t		inobt;

	struct xfs_inobt_key		inobt;

	struct xfs_rmap_key		rmap;

};



/*
@@ -56,13 +57,18 @@ union xfs_btree_bigkey { 
	xfs_bmdr_key_t			bmbr;	/* bmbt root block */

	xfs_alloc_key_t			alloc;

	struct xfs_inobt_key		inobt;

	struct {

		struct xfs_rmap_key	rmap;

		struct xfs_rmap_key	rmap_hi;

	};

};



union xfs_btree_rec {

	xfs_bmbt_rec_t		bmbt;

	struct xfs_bmbt_rec		bmbt;

	xfs_bmdr_rec_t			bmbr;	/* bmbt root block */

	xfs_alloc_rec_t		alloc;

	xfs_inobt_rec_t		inobt;

	struct xfs_alloc_rec		alloc;

	struct xfs_inobt_rec		inobt;

	struct xfs_rmap_rec		rmap;

};



/*

fs/xfs/libxfs/xfs_format.h

+73 −0
Original line number Diff line number Diff line
@@ -1347,6 +1347,79 @@ struct xfs_owner_info { 
#define XFS_RMAP_OWN_INODES	(-7ULL)	/* Inode chunk */

#define XFS_RMAP_OWN_MIN	(-8ULL) /* guard */



#define XFS_RMAP_NON_INODE_OWNER(owner)	(!!((owner) & (1ULL << 63)))



/*

 * Data record structure

 */

struct xfs_rmap_rec {

	__be32		rm_startblock;	/* extent start block */

	__be32		rm_blockcount;	/* extent length */

	__be64		rm_owner;	/* extent owner */

	__be64		rm_offset;	/* offset within the owner */

};



/*

 * rmap btree record

 *  rm_offset:63 is the attribute fork flag

 *  rm_offset:62 is the bmbt block flag

 *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)

 *  rm_offset:54-60 aren't used and should be zero

 *  rm_offset:0-53 is the block offset within the inode

 */

#define XFS_RMAP_OFF_ATTR_FORK	((__uint64_t)1ULL << 63)

#define XFS_RMAP_OFF_BMBT_BLOCK	((__uint64_t)1ULL << 62)

#define XFS_RMAP_OFF_UNWRITTEN	((__uint64_t)1ULL << 61)



#define XFS_RMAP_LEN_MAX	((__uint32_t)~0U)

#define XFS_RMAP_OFF_FLAGS	(XFS_RMAP_OFF_ATTR_FORK | \

				 XFS_RMAP_OFF_BMBT_BLOCK | \

				 XFS_RMAP_OFF_UNWRITTEN)

#define XFS_RMAP_OFF_MASK	((__uint64_t)0x3FFFFFFFFFFFFFULL)



#define XFS_RMAP_OFF(off)		((off) & XFS_RMAP_OFF_MASK)



#define XFS_RMAP_IS_BMBT_BLOCK(off)	(!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))

#define XFS_RMAP_IS_ATTR_FORK(off)	(!!((off) & XFS_RMAP_OFF_ATTR_FORK))

#define XFS_RMAP_IS_UNWRITTEN(len)	(!!((off) & XFS_RMAP_OFF_UNWRITTEN))



#define RMAPBT_STARTBLOCK_BITLEN	32

#define RMAPBT_BLOCKCOUNT_BITLEN	32

#define RMAPBT_OWNER_BITLEN		64

#define RMAPBT_ATTRFLAG_BITLEN		1

#define RMAPBT_BMBTFLAG_BITLEN		1

#define RMAPBT_EXNTFLAG_BITLEN		1

#define RMAPBT_UNUSED_OFFSET_BITLEN	7

#define RMAPBT_OFFSET_BITLEN		54



#define XFS_RMAP_ATTR_FORK		(1 << 0)

#define XFS_RMAP_BMBT_BLOCK		(1 << 1)

#define XFS_RMAP_UNWRITTEN		(1 << 2)

#define XFS_RMAP_KEY_FLAGS		(XFS_RMAP_ATTR_FORK | \

					 XFS_RMAP_BMBT_BLOCK)

#define XFS_RMAP_REC_FLAGS		(XFS_RMAP_UNWRITTEN)

struct xfs_rmap_irec {

	xfs_agblock_t	rm_startblock;	/* extent start block */

	xfs_extlen_t	rm_blockcount;	/* extent length */

	__uint64_t	rm_owner;	/* extent owner */

	__uint64_t	rm_offset;	/* offset within the owner */

	unsigned int	rm_flags;	/* state flags */

};



/*

 * Key structure

 *

 * We don't use the length for lookups

 */

struct xfs_rmap_key {

	__be32		rm_startblock;	/* extent start block */

	__be64		rm_owner;	/* extent owner */

	__be64		rm_offset;	/* offset within the owner */

} __attribute__((packed));



/* btree pointer type */

typedef __be32 xfs_rmap_ptr_t;



#define	XFS_RMAP_BLOCK(mp) \

	(xfs_sb_version_hasfinobt(&((mp)->m_sb)) ? \

	 XFS_FIBT_BLOCK(mp) + 1 : \

fs/xfs/libxfs/xfs_rmap.h

+67 −0
Original line number Diff line number Diff line
@@ -68,6 +68,73 @@ xfs_rmap_skip_owner_update( 


struct xfs_buf;



static inline __u64

xfs_rmap_irec_offset_pack(

	const struct xfs_rmap_irec	*irec)

{

	__u64			x;



	x = XFS_RMAP_OFF(irec->rm_offset);

	if (irec->rm_flags & XFS_RMAP_ATTR_FORK)

		x |= XFS_RMAP_OFF_ATTR_FORK;

	if (irec->rm_flags & XFS_RMAP_BMBT_BLOCK)

		x |= XFS_RMAP_OFF_BMBT_BLOCK;

	if (irec->rm_flags & XFS_RMAP_UNWRITTEN)

		x |= XFS_RMAP_OFF_UNWRITTEN;

	return x;

}



static inline int

xfs_rmap_irec_offset_unpack(

	__u64			offset,

	struct xfs_rmap_irec	*irec)

{

	if (offset & ~(XFS_RMAP_OFF_MASK | XFS_RMAP_OFF_FLAGS))

		return -EFSCORRUPTED;

	irec->rm_offset = XFS_RMAP_OFF(offset);

	if (offset & XFS_RMAP_OFF_ATTR_FORK)

		irec->rm_flags |= XFS_RMAP_ATTR_FORK;

	if (offset & XFS_RMAP_OFF_BMBT_BLOCK)

		irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;

	if (offset & XFS_RMAP_OFF_UNWRITTEN)

		irec->rm_flags |= XFS_RMAP_UNWRITTEN;

	return 0;

}



static inline void

xfs_owner_info_unpack(

	struct xfs_owner_info	*oinfo,

	uint64_t		*owner,

	uint64_t		*offset,

	unsigned int		*flags)

{

	unsigned int		r = 0;



	*owner = oinfo->oi_owner;

	*offset = oinfo->oi_offset;

	if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK)

		r |= XFS_RMAP_ATTR_FORK;

	if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK)

		r |= XFS_RMAP_BMBT_BLOCK;

	*flags = r;

}



static inline void

xfs_owner_info_pack(

	struct xfs_owner_info	*oinfo,

	uint64_t		owner,

	uint64_t		offset,

	unsigned int		flags)

{

	oinfo->oi_owner = owner;

	oinfo->oi_offset = XFS_RMAP_OFF(offset);

	oinfo->oi_flags = 0;

	if (flags & XFS_RMAP_ATTR_FORK)

		oinfo->oi_flags |= XFS_OWNER_INFO_ATTR_FORK;

	if (flags & XFS_RMAP_BMBT_BLOCK)

		oinfo->oi_flags |= XFS_OWNER_INFO_BMBT_BLOCK;

}



int xfs_rmap_alloc(struct xfs_trans *tp, struct xfs_buf *agbp,

		   xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len,

		   struct xfs_owner_info *oinfo);

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