Commit e069d549 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: constrain dirty buffers while formatting a staged btree 



Constrain the number of dirty buffers that are locked by the btree
staging code at any given time by establishing a threshold at which we
put them all on the delwri queue and push them to disk.  This limits
memory consumption while writing out new btrees.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 6dfeb0c2

fs/xfs/libxfs/xfs_btree_staging.c

+39 −11
Original line number Diff line number Diff line
@@ -333,24 +333,41 @@ xfs_btree_commit_ifakeroot( 
/*

 * Put a btree block that we're loading onto the ordered list and release it.

 * The btree blocks will be written to disk when bulk loading is finished.

 * If we reach the dirty buffer threshold, flush them to disk before

 * continuing.

 */

static void

static int

xfs_btree_bload_drop_buf(

	struct xfs_btree_bload		*bbl,

	struct list_head		*buffers_list,

	struct xfs_buf			**bpp)

{

	if (*bpp == NULL)

		return;

	struct xfs_buf			*bp = *bpp;

	int				error;



	if (!bp)

		return 0;



	/*

	 * Mark this buffer XBF_DONE (i.e. uptodate) so that a subsequent

	 * xfs_buf_read will not pointlessly reread the contents from the disk.

	 */

	(*bpp)->b_flags |= XBF_DONE;

	bp->b_flags |= XBF_DONE;



	xfs_buf_delwri_queue_here(*bpp, buffers_list);

	xfs_buf_relse(*bpp);

	xfs_buf_delwri_queue_here(bp, buffers_list);

	xfs_buf_relse(bp);

	*bpp = NULL;

	bbl->nr_dirty++;



	if (!bbl->max_dirty || bbl->nr_dirty < bbl->max_dirty)

		return 0;



	error = xfs_buf_delwri_submit(buffers_list);

	if (error)

		return error;



	bbl->nr_dirty = 0;

	return 0;

}



/*
@@ -422,7 +439,10 @@ xfs_btree_bload_prep_block( 
	 */

	if (*blockp)

		xfs_btree_set_sibling(cur, *blockp, &new_ptr, XFS_BB_RIGHTSIB);

	xfs_btree_bload_drop_buf(buffers_list, bpp);



	ret = xfs_btree_bload_drop_buf(bbl, buffers_list, bpp);

	if (ret)

		return ret;



	/* Initialize the new btree block. */

	xfs_btree_init_block_cur(cur, new_bp, level, nr_this_block);
@@ -770,6 +790,7 @@ xfs_btree_bload( 
	cur->bc_nlevels = bbl->btree_height;

	xfs_btree_set_ptr_null(cur, &child_ptr);

	xfs_btree_set_ptr_null(cur, &ptr);

	bbl->nr_dirty = 0;



	xfs_btree_bload_level_geometry(cur, bbl, level, nr_this_level,

			&avg_per_block, &blocks, &blocks_with_extra);
@@ -808,7 +829,10 @@ xfs_btree_bload( 
			xfs_btree_copy_ptrs(cur, &child_ptr, &ptr, 1);

	}

	total_blocks += blocks;

	xfs_btree_bload_drop_buf(&buffers_list, &bp);



	ret = xfs_btree_bload_drop_buf(bbl, &buffers_list, &bp);

	if (ret)

		goto out;



	/* Populate the internal btree nodes. */

	for (level = 1; level < cur->bc_nlevels; level++) {
@@ -850,7 +874,11 @@ xfs_btree_bload( 
				xfs_btree_copy_ptrs(cur, &first_ptr, &ptr, 1);

		}

		total_blocks += blocks;

		xfs_btree_bload_drop_buf(&buffers_list, &bp);



		ret = xfs_btree_bload_drop_buf(bbl, &buffers_list, &bp);

		if (ret)

			goto out;



		xfs_btree_copy_ptrs(cur, &child_ptr, &first_ptr, 1);

	}

fs/xfs/libxfs/xfs_btree_staging.h

+10 −0
Original line number Diff line number Diff line
@@ -112,6 +112,16 @@ struct xfs_btree_bload { 
	 * height of the new btree.

	 */

	unsigned int			btree_height;



	/*

	 * Flush the new btree block buffer list to disk after this many blocks

	 * have been formatted.  Zero prohibits writing any buffers until all

	 * blocks have been formatted.

	 */

	uint16_t			max_dirty;



	/* Number of dirty buffers. */

	uint16_t			nr_dirty;

};



int xfs_btree_bload_compute_geometry(struct xfs_btree_cur *cur,

fs/xfs/scrub/newbt.c

+1 −0
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ xrep_newbt_init_ag( 
	xnr->alloc_hint = alloc_hint;

	xnr->resv = resv;

	INIT_LIST_HEAD(&xnr->resv_list);

	xnr->bload.max_dirty = XFS_B_TO_FSBT(sc->mp, 256U << 10); /* 256K */

	xrep_newbt_estimate_slack(xnr);

}