Commit aa8759d8 authored by Hans Holmberg's avatar Hans Holmberg Committed by Jens Axboe
Browse files

lightnvm: pblk: extend line wp balance check 



pblk stripes writes of minimal write size across all non-offline chunks
in a line, which means that the maximum write pointer delta should not
exceed the minimal write size.

Extend the line write pointer balance check to cover this case, and
ignore the offline chunk wps.

This will render us a warning during recovery if something unexpected
has happened to the chunk write pointers (i.e. powerloss,  a spurious
chunk reset, ..).

Reported-by: default avatarZhoujie Wu <zjwu@marvell.com>
Tested-by: default avatarZhoujie Wu <zjwu@marvell.com>
Reviewed-by: default avatarJavier González <javier@javigon.com>
Signed-off-by: default avatarHans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: default avatarMatias Bjørling <mb@lightnvm.io>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b7fce8f7

drivers/lightnvm/pblk-recovery.c

+38 −18
Original line number Diff line number Diff line
@@ -302,35 +302,55 @@ static int pblk_pad_distance(struct pblk *pblk, struct pblk_line *line) 
	return (distance > line->left_msecs) ? line->left_msecs : distance;

}



static int pblk_line_wp_is_unbalanced(struct pblk *pblk,

				      struct pblk_line *line)

/* Return a chunk belonging to a line by stripe(write order) index */

static struct nvm_chk_meta *pblk_get_stripe_chunk(struct pblk *pblk,

						  struct pblk_line *line,

						  int index)

{

	struct nvm_tgt_dev *dev = pblk->dev;

	struct nvm_geo *geo = &dev->geo;

	struct pblk_line_meta *lm = &pblk->lm;

	struct pblk_lun *rlun;

	struct nvm_chk_meta *chunk;

	struct ppa_addr ppa;

	u64 line_wp;

	int pos, i;

	int pos;



	rlun = &pblk->luns[0];

	rlun = &pblk->luns[index];

	ppa = rlun->bppa;

	pos = pblk_ppa_to_pos(geo, ppa);

	chunk = &line->chks[pos];



	line_wp = chunk->wp;

	return &line->chks[pos];

}



	for (i = 1; i < lm->blk_per_line; i++) {

		rlun = &pblk->luns[i];

		ppa = rlun->bppa;

		pos = pblk_ppa_to_pos(geo, ppa);

		chunk = &line->chks[pos];

static int pblk_line_wps_are_unbalanced(struct pblk *pblk,

				      struct pblk_line *line)

{

	struct pblk_line_meta *lm = &pblk->lm;

	int blk_in_line = lm->blk_per_line;

	struct nvm_chk_meta *chunk;

	u64 max_wp, min_wp;

	int i;



	i = find_first_zero_bit(line->blk_bitmap, blk_in_line);



		if (chunk->wp > line_wp)

	/* If there is one or zero good chunks in the line,

	 * the write pointers can't be unbalanced.

	 */

	if (i >= (blk_in_line - 1))

		return 0;



	chunk = pblk_get_stripe_chunk(pblk, line, i);

	max_wp = chunk->wp;

	if (max_wp > pblk->max_write_pgs)

		min_wp = max_wp - pblk->max_write_pgs;

	else

		min_wp = 0;



	i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);

	while (i < blk_in_line) {

		chunk = pblk_get_stripe_chunk(pblk, line, i);

		if (chunk->wp > max_wp || chunk->wp < min_wp)

			return 1;

		else if (chunk->wp < line_wp)

			line_wp = chunk->wp;



		i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);

	}



	return 0;
@@ -356,7 +376,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line, 
	int ret;

	u64 left_ppas = pblk_sec_in_open_line(pblk, line) - lm->smeta_sec;



	if (pblk_line_wp_is_unbalanced(pblk, line))

	if (pblk_line_wps_are_unbalanced(pblk, line))

		pblk_warn(pblk, "recovering unbalanced line (%d)\n", line->id);



	ppa_list = p.ppa_list;

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