Commit b2b1712a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Darrick J. Wong
Browse files

xfs: introduce the xfs_iext_cursor abstraction 



Add a new xfs_iext_cursor structure to hide the direct extent map
index manipulations. In addition to the existing lookup/get/insert/
remove and update routines new primitives to get the first and last
extent cursor, as well as moving up and down by one extent are
provided.  Also new are convenience to increment/decrement the
cursor and retreive the new extent, as well as to peek into the
previous/next extent without updating the cursor and last but not
least a macro to iterate over all extents in a fork.

[darrick: rename for_each_iext to for_each_xfs_iext]

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 906abed5

fs/xfs/libxfs/xfs_bmap.c

+212 −229

File changed.

Preview size limit exceeded, changes collapsed.

fs/xfs/libxfs/xfs_bmap.h

+7 −5
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ struct xfs_bmalloca { 
	xfs_fsblock_t		blkno;	/* starting block of new extent */



	struct xfs_btree_cur	*cur;	/* btree cursor */

	xfs_extnum_t		idx;	/* current extent index */

	struct xfs_iext_cursor	icur;	/* incore extent cursor */

	int			nallocs;/* number of extents alloc'd */

	int			logflags;/* flags for transaction logging */
@@ -216,10 +216,11 @@ int xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip, 
		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,

		struct xfs_defer_ops *dfops, int *done);

int	xfs_bmap_del_extent_delay(struct xfs_inode *ip, int whichfork,

		xfs_extnum_t *idx, struct xfs_bmbt_irec *got,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,

		struct xfs_bmbt_irec *del);

void	xfs_bmap_del_extent_cow(struct xfs_inode *ip,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,

		struct xfs_bmbt_irec *del);

void	xfs_bmap_del_extent_cow(struct xfs_inode *ip, xfs_extnum_t *idx,

		struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *del);

uint	xfs_default_attroffset(struct xfs_inode *ip);

int	xfs_bmap_collapse_extents(struct xfs_trans *tp, struct xfs_inode *ip,

		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
@@ -232,7 +233,8 @@ int xfs_bmap_insert_extents(struct xfs_trans *tp, struct xfs_inode *ip, 
int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);

int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,

		xfs_fileoff_t off, xfs_filblks_t len, xfs_filblks_t prealloc,

		struct xfs_bmbt_irec *got, xfs_extnum_t *lastx, int eof);

		struct xfs_bmbt_irec *got, struct xfs_iext_cursor *cur,

		int eof);



enum xfs_bmap_intent_type {

	XFS_BMAP_MAP = 1,

fs/xfs/libxfs/xfs_inode_fork.c

+41 −34
Original line number Diff line number Diff line
@@ -343,6 +343,7 @@ xfs_iformat_extents( 
	int			state = xfs_bmap_fork_to_state(whichfork);

	int			nex = XFS_DFORK_NEXTENTS(dip, whichfork);

	int			size = nex * sizeof(xfs_bmbt_rec_t);

	struct xfs_iext_cursor	icur;

	struct xfs_bmbt_rec	*dp;

	int			i;
@@ -369,16 +370,21 @@ xfs_iformat_extents( 
	ifp->if_bytes = size;

	if (size) {

		dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);



		xfs_iext_first(ifp, &icur);

		for (i = 0; i < nex; i++, dp++) {

			xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);



			if (!xfs_bmbt_validate_extent(mp, whichfork, dp)) {

				XFS_ERROR_REPORT("xfs_iformat_extents(2)",

						 XFS_ERRLEVEL_LOW, mp);

				return -EFSCORRUPTED;

			}



			ep->l0 = get_unaligned_be64(&dp->l0);

			ep->l1 = get_unaligned_be64(&dp->l1);

			trace_xfs_read_extent(ip, i, state, _THIS_IP_);

			trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);

			xfs_iext_next(ifp, &icur);

		}

	}

	ifp->if_flags |= XFS_IFEXTENTS;
@@ -739,17 +745,18 @@ xfs_iextents_copy( 
{

	int			state = xfs_bmap_fork_to_state(whichfork);

	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);

	struct xfs_iext_cursor	icur;

	struct xfs_bmbt_irec	rec;

	int			copied = 0, i = 0;

	int			copied = 0;



	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));

	ASSERT(ifp->if_bytes > 0);



	while (xfs_iext_get_extent(ifp, i++, &rec)) {

	for_each_xfs_iext(ifp, &icur, &rec) {

		if (isnullstartblock(rec.br_startblock))

			continue;

		xfs_bmbt_disk_set_all(dp, &rec);

		trace_xfs_write_extent(ip, i, state, _RET_IP_);

		trace_xfs_write_extent(ip, &icur, state, _RET_IP_);

		ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, dp));

		copied += sizeof(struct xfs_bmbt_rec);

		dp++;
@@ -894,7 +901,7 @@ xfs_iext_state_to_fork( 
void

xfs_iext_insert(

	xfs_inode_t	*ip,		/* incore inode pointer */

	xfs_extnum_t	idx,		/* starting index of new items */

	struct xfs_iext_cursor *cur,

	xfs_extnum_t	count,		/* number of inserted items */

	xfs_bmbt_irec_t	*new,		/* items to insert */

	int		state)		/* type of extent conversion */
@@ -902,12 +909,12 @@ xfs_iext_insert( 
	xfs_ifork_t	*ifp = xfs_iext_state_to_fork(ip, state);

	xfs_extnum_t	i;		/* extent record index */



	trace_xfs_iext_insert(ip, idx, new, state, _RET_IP_);

	trace_xfs_iext_insert(ip, cur->idx, new, state, _RET_IP_);



	ASSERT(ifp->if_flags & XFS_IFEXTENTS);

	xfs_iext_add(ifp, idx, count);

	for (i = idx; i < idx + count; i++, new++)

		xfs_bmbt_set_all(xfs_iext_get_ext(ifp, i), new);

	xfs_iext_add(ifp, cur->idx, count);

	for (i = 0; i < count; i++, new++)

		xfs_bmbt_set_all(xfs_iext_get_ext(ifp, cur->idx + i), new);

}



/*
@@ -1145,7 +1152,7 @@ xfs_iext_add_indirect_multi( 
void

xfs_iext_remove(

	xfs_inode_t	*ip,		/* incore inode pointer */

	xfs_extnum_t	idx,		/* index to begin removing exts */

	struct xfs_iext_cursor *cur,

	int		ext_diff,	/* number of extents to remove */

	int		state)		/* type of extent conversion */

{
@@ -1153,7 +1160,7 @@ xfs_iext_remove( 
	xfs_extnum_t	nextents;	/* number of extents in file */

	int		new_size;	/* size of extents after removal */



	trace_xfs_iext_remove(ip, idx, state, _RET_IP_);

	trace_xfs_iext_remove(ip, cur, state, _RET_IP_);



	ASSERT(ext_diff > 0);

	nextents = xfs_iext_count(ifp);
@@ -1162,11 +1169,11 @@ xfs_iext_remove( 
	if (new_size == 0) {

		xfs_iext_destroy(ifp);

	} else if (ifp->if_flags & XFS_IFEXTIREC) {

		xfs_iext_remove_indirect(ifp, idx, ext_diff);

		xfs_iext_remove_indirect(ifp, cur->idx, ext_diff);

	} else if (ifp->if_real_bytes) {

		xfs_iext_remove_direct(ifp, idx, ext_diff);

		xfs_iext_remove_direct(ifp, cur->idx, ext_diff);

	} else {

		xfs_iext_remove_inline(ifp, idx, ext_diff);

		xfs_iext_remove_inline(ifp, cur->idx, ext_diff);

	}

	ifp->if_bytes = new_size;

}
@@ -1913,26 +1920,26 @@ xfs_ifork_init_cow( 
 * Lookup the extent covering bno.

 *

 * If there is an extent covering bno return the extent index, and store the

 * expanded extent structure in *gotp, and the extent index in *idx.

 * expanded extent structure in *gotp, and the extent cursor in *cur.

 * If there is no extent covering bno, but there is an extent after it (e.g.

 * it lies in a hole) return that extent in *gotp and its index in *idx

 * it lies in a hole) return that extent in *gotp and its cursor in *cur

 * instead.

 * If bno is beyond the last extent return false, and return the index after

 * the last valid index in *idxp.

 * If bno is beyond the last extent return false, and return an invalid

 * cursor value.

 */

bool

xfs_iext_lookup_extent(

	struct xfs_inode	*ip,

	struct xfs_ifork	*ifp,

	xfs_fileoff_t		bno,

	xfs_extnum_t		*idxp,

	struct xfs_iext_cursor	*cur,

	struct xfs_bmbt_irec	*gotp)

{

	struct xfs_bmbt_rec_host *ep;



	XFS_STATS_INC(ip->i_mount, xs_look_exlist);



	ep = xfs_iext_bno_to_ext(ifp, bno, idxp);

	ep = xfs_iext_bno_to_ext(ifp, bno, &cur->idx);

	if (!ep)

		return false;

	xfs_bmbt_get_all(ep, gotp);
@@ -1948,31 +1955,31 @@ xfs_iext_lookup_extent_before( 
	struct xfs_inode	*ip,

	struct xfs_ifork	*ifp,

	xfs_fileoff_t		*end,

	xfs_extnum_t		*idxp,

	struct xfs_iext_cursor	*cur,

	struct xfs_bmbt_irec	*gotp)

{

	if (xfs_iext_lookup_extent(ip, ifp, *end - 1, idxp, gotp) &&

	if (xfs_iext_lookup_extent(ip, ifp, *end - 1, cur, gotp) &&

	    gotp->br_startoff <= *end - 1)

		return true;

	if (!xfs_iext_get_extent(ifp, --*idxp, gotp))

	if (!xfs_iext_prev_extent(ifp, cur, gotp))

		return false;

	*end = gotp->br_startoff + gotp->br_blockcount;

	return true;

}



/*

 * Return true if there is an extent at index idx, and return the expanded

 * extent structure at idx in that case.  Else return false.

 * Return true if the cursor points at an extent and return the extent structure

 * in gotp.  Else return false.

 */

bool

xfs_iext_get_extent(

	struct xfs_ifork	*ifp,

	xfs_extnum_t		idx,

	struct xfs_iext_cursor	*cur,

	struct xfs_bmbt_irec	*gotp)

{

	if (idx < 0 || idx >= xfs_iext_count(ifp))

	if (cur->idx < 0 || cur->idx >= xfs_iext_count(ifp))

		return false;

	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), gotp);

	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, cur->idx), gotp);

	return true;

}
@@ -1980,15 +1987,15 @@ void 
xfs_iext_update_extent(

	struct xfs_inode	*ip,

	int			state,

	xfs_extnum_t		idx,

	struct xfs_iext_cursor	*cur,

	struct xfs_bmbt_irec	*gotp)

{

	struct xfs_ifork	*ifp = xfs_iext_state_to_fork(ip, state);



	ASSERT(idx >= 0);

	ASSERT(idx < xfs_iext_count(ifp));

	ASSERT(cur->idx >= 0);

	ASSERT(cur->idx < xfs_iext_count(ifp));



	trace_xfs_bmap_pre_update(ip, idx, state, _RET_IP_);

	xfs_bmbt_set_all(xfs_iext_get_ext(ifp, idx), gotp);

	trace_xfs_bmap_post_update(ip, idx, state, _RET_IP_);

	trace_xfs_bmap_pre_update(ip, cur, state, _RET_IP_);

	xfs_bmbt_set_all(xfs_iext_get_ext(ifp, cur->idx), gotp);

	trace_xfs_bmap_post_update(ip, cur, state, _RET_IP_);

}

fs/xfs/libxfs/xfs_inode_fork.h

+79 −8
Original line number Diff line number Diff line
@@ -151,12 +151,13 @@ void xfs_init_local_fork(struct xfs_inode *, int, const void *, int); 
struct xfs_bmbt_rec_host *

		xfs_iext_get_ext(struct xfs_ifork *, xfs_extnum_t);

xfs_extnum_t	xfs_iext_count(struct xfs_ifork *);

void		xfs_iext_insert(struct xfs_inode *, xfs_extnum_t, xfs_extnum_t,

				struct xfs_bmbt_irec *, int);

void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,

			xfs_extnum_t, struct xfs_bmbt_irec *, int);

void		xfs_iext_add(struct xfs_ifork *, xfs_extnum_t, int);

void		xfs_iext_add_indirect_multi(struct xfs_ifork *, int,

					    xfs_extnum_t, int);

void		xfs_iext_remove(struct xfs_inode *, xfs_extnum_t, int, int);

void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,

			int, int);

void		xfs_iext_remove_inline(struct xfs_ifork *, xfs_extnum_t, int);

void		xfs_iext_remove_direct(struct xfs_ifork *, xfs_extnum_t, int);

void		xfs_iext_remove_indirect(struct xfs_ifork *, xfs_extnum_t, int);
@@ -182,15 +183,85 @@ void xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int); 


bool		xfs_iext_lookup_extent(struct xfs_inode *ip,

			struct xfs_ifork *ifp, xfs_fileoff_t bno,

			xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp);

			struct xfs_iext_cursor *cur,

			struct xfs_bmbt_irec *gotp);

bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,

			struct xfs_ifork *ifp, xfs_fileoff_t *end,

			xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp);



bool		xfs_iext_get_extent(struct xfs_ifork *ifp, xfs_extnum_t idx,

			struct xfs_iext_cursor *cur,

			struct xfs_bmbt_irec *gotp);

bool		xfs_iext_get_extent(struct xfs_ifork *ifp,

			struct xfs_iext_cursor *cur,

			struct xfs_bmbt_irec *gotp);

void		xfs_iext_update_extent(struct xfs_inode *ip, int state,

			xfs_extnum_t idx, struct xfs_bmbt_irec *gotp);

			struct xfs_iext_cursor *cur,

			struct xfs_bmbt_irec *gotp);



static inline void xfs_iext_first(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur)

{

	cur->idx = 0;

}



static inline void xfs_iext_last(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur)

{

	cur->idx = xfs_iext_count(ifp) - 1;

}



static inline void xfs_iext_next(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur)

{

	cur->idx++;

}



static inline void xfs_iext_prev(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur)

{

	cur->idx--;

}



static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)

{

	xfs_iext_next(ifp, cur);

	return xfs_iext_get_extent(ifp, cur, gotp);

}



static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)

{

	xfs_iext_prev(ifp, cur);

	return xfs_iext_get_extent(ifp, cur, gotp);

}



/*

 * Return the extent after cur in gotp without updating the cursor.

 */

static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)

{

	struct xfs_iext_cursor ncur = *cur;



	xfs_iext_next(ifp, &ncur);

	return xfs_iext_get_extent(ifp, &ncur, gotp);

}



/*

 * Return the extent before cur in gotp without updating the cursor.

 */

static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,

		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)

{

	struct xfs_iext_cursor ncur = *cur;



	xfs_iext_prev(ifp, &ncur);

	return xfs_iext_get_extent(ifp, &ncur, gotp);

}



#define for_each_xfs_iext(ifp, ext, got)		\

	for (xfs_iext_first((ifp), (ext));		\

	     xfs_iext_get_extent((ifp), (ext), (got));	\

	     xfs_iext_next((ifp), (ext)))



extern struct kmem_zone	*xfs_ifork_zone;

fs/xfs/libxfs/xfs_types.h

+3 −0
Original line number Diff line number Diff line
@@ -142,5 +142,8 @@ typedef uint32_t xfs_dqid_t; 
#define	XFS_NBWORD	(1 << XFS_NBWORDLOG)

#define	XFS_WORDMASK	((1 << XFS_WORDLOG) - 1)



struct xfs_iext_cursor {

	xfs_extnum_t		idx;

};



#endif	/* __XFS_TYPES_H__ */

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