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Commit ea7cdd7b authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: separate function to check if inode shares extents 



Separate the "clear reflink flag" function into one function that checks
if the flag is needed, and a second function that checks and clears the
flag.  The inode scrub code will want to check the necessity of the flag
without clearing it.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
parent 92ff7285

fs/xfs/xfs_reflink.c

+52 −36
Original line number Diff line number Diff line
@@ -1406,57 +1406,73 @@ xfs_reflink_dirty_extents( 
	return error;

}



/* Clear the inode reflink flag if there are no shared extents. */

/* Does this inode need the reflink flag? */

int

xfs_reflink_clear_inode_flag(

xfs_reflink_inode_has_shared_extents(

	struct xfs_trans		*tp,

	struct xfs_inode		*ip,

	struct xfs_trans	**tpp)

	bool				*has_shared)

{

	struct xfs_bmbt_irec		got;

	struct xfs_mount		*mp = ip->i_mount;

	xfs_fileoff_t		fbno;

	xfs_filblks_t		end;

	struct xfs_ifork		*ifp;

	xfs_agnumber_t			agno;

	xfs_agblock_t			agbno;

	xfs_extlen_t			aglen;

	xfs_agblock_t			rbno;

	xfs_extlen_t			rlen;

	struct xfs_bmbt_irec	map;

	int			nmaps;

	int			error = 0;



	ASSERT(xfs_is_reflink_inode(ip));

	xfs_extnum_t			idx;

	bool				found;

	int				error;



	fbno = 0;

	end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip)));

	while (end - fbno > 0) {

		nmaps = 1;

		/*

		 * Look for extents in the file.  Skip holes, delalloc, or

		 * unwritten extents; they can't be reflinked.

		 */

		error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0);

	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);

	if (!(ifp->if_flags & XFS_IFEXTENTS)) {

		error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);

		if (error)

			return error;

		if (nmaps == 0)

			break;

		if (!xfs_bmap_is_real_extent(&map))

			goto next;

	}



		agno = XFS_FSB_TO_AGNO(mp, map.br_startblock);

		agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock);

		aglen = map.br_blockcount;

	*has_shared = false;

	found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &got);

	while (found) {

		if (isnullstartblock(got.br_startblock) ||

		    got.br_state != XFS_EXT_NORM)

			goto next;

		agno = XFS_FSB_TO_AGNO(mp, got.br_startblock);

		agbno = XFS_FSB_TO_AGBNO(mp, got.br_startblock);

		aglen = got.br_blockcount;



		error = xfs_reflink_find_shared(mp, *tpp, agno, agbno, aglen,

		error = xfs_reflink_find_shared(mp, tp, agno, agbno, aglen,

				&rbno, &rlen, false);

		if (error)

			return error;

		/* Is there still a shared block here? */

		if (rbno != NULLAGBLOCK)

		if (rbno != NULLAGBLOCK) {

			*has_shared = true;

			return 0;

		}

next:

		fbno = map.br_startoff + map.br_blockcount;

		found = xfs_iext_get_extent(ifp, ++idx, &got);

	}



	return 0;

}



/* Clear the inode reflink flag if there are no shared extents. */

int

xfs_reflink_clear_inode_flag(

	struct xfs_inode	*ip,

	struct xfs_trans	**tpp)

{

	bool			needs_flag;

	int			error = 0;



	ASSERT(xfs_is_reflink_inode(ip));



	error = xfs_reflink_inode_has_shared_extents(*tpp, ip, &needs_flag);

	if (error || needs_flag)

		return error;



	/*

	 * We didn't find any shared blocks so turn off the reflink flag.

	 * First, get rid of any leftover CoW mappings.

fs/xfs/xfs_reflink.h

+2 −0
Original line number Diff line number Diff line
@@ -47,6 +47,8 @@ extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset, 
extern int xfs_reflink_recover_cow(struct xfs_mount *mp);

extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,

		struct file *file_out, loff_t pos_out, u64 len, bool is_dedupe);

extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,

		struct xfs_inode *ip, bool *has_shared);

extern int xfs_reflink_clear_inode_flag(struct xfs_inode *ip,

		struct xfs_trans **tpp);

extern int xfs_reflink_unshare(struct xfs_inode *ip, xfs_off_t offset,