Commit 89563e7d authored by Dave Chinner's avatar Dave Chinner
Browse files

xfs: factor out filestreams from xfs_bmap_btalloc_nullfb 



There's many if (filestreams) {} else {} branches in this function.
Split it out into a filestreams specific function so that we can
then work directly on cleaning up the filestreams code without
impacting the rest of the allocation algorithms.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent 35bf2b1a

fs/xfs/libxfs/xfs_bmap.c

+96 −71
Original line number Diff line number Diff line
@@ -3234,8 +3234,8 @@ xfs_bmap_btalloc_select_lengths( 
	return error;

}



STATIC int

xfs_bmap_btalloc_filestreams(

static int

xfs_bmap_btalloc_filestreams_select_lengths(

	struct xfs_bmalloca	*ap,

	struct xfs_alloc_arg	*args,

	xfs_extlen_t		*blen)
@@ -3576,40 +3576,57 @@ xfs_bmap_btalloc_at_eof( 
	return 0;

}



/*

 * We have failed multiple allocation attempts so now are in a low space

 * allocation situation. Try a locality first full filesystem minimum length

 * allocation whilst still maintaining necessary total block reservation

 * requirements.

 *

 * If that fails, we are now critically low on space, so perform a last resort

 * allocation attempt: no reserve, no locality, blocking, minimum length, full

 * filesystem free space scan. We also indicate to future allocations in this

 * transaction that we are critically low on space so they don't waste time on

 * allocation modes that are unlikely to succeed.

 */

static int

xfs_bmap_btalloc_best_length(

xfs_bmap_btalloc_low_space(

	struct xfs_bmalloca	*ap,

	struct xfs_alloc_arg	*args)

{

	int			error;



	if (args->minlen > ap->minlen) {

		args->minlen = ap->minlen;

		error = xfs_alloc_vextent_start_ag(args, ap->blkno);

		if (error || args->fsbno != NULLFSBLOCK)

			return error;

	}



	/* Last ditch attempt before failure is declared. */

	args->total = ap->minlen;

	error = xfs_alloc_vextent_first_ag(args, 0);

	if (error)

		return error;

	ap->tp->t_flags |= XFS_TRANS_LOWMODE;

	return 0;

}



static int

xfs_bmap_btalloc_filestreams(

	struct xfs_bmalloca	*ap,

	struct xfs_alloc_arg	*args,

	int			stripe_align)

{

	struct xfs_mount	*mp = args->mp;

	xfs_agnumber_t		agno = xfs_filestream_lookup_ag(ap->ip);

	xfs_extlen_t		blen = 0;

	bool			is_filestream = false;

	int			error;



	if ((ap->datatype & XFS_ALLOC_USERDATA) &&

	    xfs_inode_is_filestream(ap->ip))

		is_filestream = true;



	/*

	 * Determine the initial block number we will target for allocation.

	 */

	if (is_filestream) {

		xfs_agnumber_t	agno = xfs_filestream_lookup_ag(ap->ip);

	/* Determine the initial block number we will target for allocation. */

	if (agno == NULLAGNUMBER)

		agno = 0;

		ap->blkno = XFS_AGB_TO_FSB(mp, agno, 0);

	} else {

		ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);

	}

	ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);

	xfs_bmap_adjacent(ap);



	/*

	 * Search for an allocation group with a single extent large enough for

	 * the request.  If one isn't found, then adjust the minimum allocation

	 * size to the largest space found.

	 */

	if (is_filestream) {

	/*

	 * If there is very little free space before we start a

	 * filestreams allocation, we're almost guaranteed to fail to
@@ -3618,67 +3635,71 @@ xfs_bmap_btalloc_best_length( 
	 */

	if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {

		args->minlen = ap->minlen;

			goto critically_low_space;

		}

		error = xfs_bmap_btalloc_filestreams(ap, args, &blen);

	} else {

		error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);

		return xfs_bmap_btalloc_low_space(ap, args);

	}

	if (error)

		return error;



	/*

	 * Don't attempt optimal EOF allocation if previous allocations barely

	 * succeeded due to being near ENOSPC. It is highly unlikely we'll get

	 * optimal or even aligned allocations in this case, so don't waste time

	 * trying.

	 * Search for an allocation group with a single extent large enough for

	 * the request.  If one isn't found, then adjust the minimum allocation

	 * size to the largest space found.

	 */

	if (ap->aeof && !(ap->tp->t_flags & XFS_TRANS_LOWMODE)) {

		error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align,

				is_filestream);

	error = xfs_bmap_btalloc_filestreams_select_lengths(ap, args, &blen);

	if (error)

		return error;

		if (args->fsbno != NULLFSBLOCK)

			return 0;



	if (ap->aeof) {

		error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align,

				true);

		if (error || args->fsbno != NULLFSBLOCK)

			return error;

	}



	if (is_filestream)

	error = xfs_alloc_vextent_near_bno(args, ap->blkno);

	else

		error = xfs_alloc_vextent_start_ag(args, ap->blkno);

	if (error)

	if (error || args->fsbno != NULLFSBLOCK)

		return error;

	if (args->fsbno != NULLFSBLOCK)

		return 0;



	return xfs_bmap_btalloc_low_space(ap, args);

}



static int

xfs_bmap_btalloc_best_length(

	struct xfs_bmalloca	*ap,

	struct xfs_alloc_arg	*args,

	int			stripe_align)

{

	xfs_extlen_t		blen = 0;

	int			error;



	ap->blkno = XFS_INO_TO_FSB(args->mp, ap->ip->i_ino);

	xfs_bmap_adjacent(ap);



	/*

	 * Try a locality first full filesystem minimum length allocation whilst

	 * still maintaining necessary total block reservation requirements.

	 * Search for an allocation group with a single extent large enough for

	 * the request.  If one isn't found, then adjust the minimum allocation

	 * size to the largest space found.

	 */

	if (args->minlen > ap->minlen) {

		args->minlen = ap->minlen;

		error = xfs_alloc_vextent_start_ag(args, ap->blkno);

	error = xfs_bmap_btalloc_select_lengths(ap, args, &blen);

	if (error)

		return error;

	}

	if (args->fsbno != NULLFSBLOCK)

		return 0;



	/*

	 * We are now critically low on space, so this is a last resort

	 * allocation attempt: no reserve, no locality, blocking, minimum

	 * length, full filesystem free space scan. We also indicate to future

	 * allocations in this transaction that we are critically low on space

	 * so they don't waste time on allocation modes that are unlikely to

	 * succeed.

	 * Don't attempt optimal EOF allocation if previous allocations barely

	 * succeeded due to being near ENOSPC. It is highly unlikely we'll get

	 * optimal or even aligned allocations in this case, so don't waste time

	 * trying.

	 */

critically_low_space:

	args->total = ap->minlen;

	error = xfs_alloc_vextent_first_ag(args, 0);

	if (error)

	if (ap->aeof && !(ap->tp->t_flags & XFS_TRANS_LOWMODE)) {

		error = xfs_bmap_btalloc_at_eof(ap, args, blen, stripe_align,

				false);

		if (error || args->fsbno != NULLFSBLOCK)

			return error;

	ap->tp->t_flags |= XFS_TRANS_LOWMODE;

	return 0;

	}



	error = xfs_alloc_vextent_start_ag(args, ap->blkno);

	if (error || args->fsbno != NULLFSBLOCK)

		return error;



	return xfs_bmap_btalloc_low_space(ap, args);

}



static int
@@ -3712,6 +3733,10 @@ xfs_bmap_btalloc( 
	/* Trim the allocation back to the maximum an AG can fit. */

	args.maxlen = min(ap->length, mp->m_ag_max_usable);



	if ((ap->datatype & XFS_ALLOC_USERDATA) &&

	    xfs_inode_is_filestream(ap->ip))

		error = xfs_bmap_btalloc_filestreams(ap, &args, stripe_align);

	else

		error = xfs_bmap_btalloc_best_length(ap, &args, stripe_align);

	if (error)

		return error;