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Commit b774ef49 authored by Yuri Tikhonov's avatar Yuri Tikhonov Committed by Dan Williams
Browse files

md/raid6: remove synchronous infrastructure



These routines have been replaced by there asynchronous counterparts.

Signed-off-by: default avatarYuri Tikhonov <yur@emcraft.com>
Signed-off-by: default avatarIlya Yanok <yanok@emcraft.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6c0069c0
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+0 −254
Original line number Diff line number Diff line
@@ -1927,253 +1927,6 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
}



/*
 * Copy data between a page in the stripe cache, and one or more bion
 * The page could align with the middle of the bio, or there could be
 * several bion, each with several bio_vecs, which cover part of the page
 * Multiple bion are linked together on bi_next.  There may be extras
 * at the end of this list.  We ignore them.
 */
static void copy_data(int frombio, struct bio *bio,
		     struct page *page,
		     sector_t sector)
{
	char *pa = page_address(page);
	struct bio_vec *bvl;
	int i;
	int page_offset;

	if (bio->bi_sector >= sector)
		page_offset = (signed)(bio->bi_sector - sector) * 512;
	else
		page_offset = (signed)(sector - bio->bi_sector) * -512;
	bio_for_each_segment(bvl, bio, i) {
		int len = bio_iovec_idx(bio,i)->bv_len;
		int clen;
		int b_offset = 0;

		if (page_offset < 0) {
			b_offset = -page_offset;
			page_offset += b_offset;
			len -= b_offset;
		}

		if (len > 0 && page_offset + len > STRIPE_SIZE)
			clen = STRIPE_SIZE - page_offset;
		else clen = len;

		if (clen > 0) {
			char *ba = __bio_kmap_atomic(bio, i, KM_USER0);
			if (frombio)
				memcpy(pa+page_offset, ba+b_offset, clen);
			else
				memcpy(ba+b_offset, pa+page_offset, clen);
			__bio_kunmap_atomic(ba, KM_USER0);
		}
		if (clen < len) /* hit end of page */
			break;
		page_offset +=  len;
	}
}

#define check_xor()	do {						  \
				if (count == MAX_XOR_BLOCKS) {		  \
				xor_blocks(count, STRIPE_SIZE, dest, ptr);\
				count = 0;				  \
			   }						  \
			} while(0)

static void compute_parity6(struct stripe_head *sh, int method)
{
	raid5_conf_t *conf = sh->raid_conf;
	int i, pd_idx, qd_idx, d0_idx, disks = sh->disks, count;
	int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
	struct bio *chosen;
	/**** FIX THIS: This could be very bad if disks is close to 256 ****/
	void *ptrs[syndrome_disks+2];

	pd_idx = sh->pd_idx;
	qd_idx = sh->qd_idx;
	d0_idx = raid6_d0(sh);

	pr_debug("compute_parity, stripe %llu, method %d\n",
		(unsigned long long)sh->sector, method);

	switch(method) {
	case READ_MODIFY_WRITE:
		BUG();		/* READ_MODIFY_WRITE N/A for RAID-6 */
	case RECONSTRUCT_WRITE:
		for (i= disks; i-- ;)
			if ( i != pd_idx && i != qd_idx && sh->dev[i].towrite ) {
				chosen = sh->dev[i].towrite;
				sh->dev[i].towrite = NULL;

				if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
					wake_up(&conf->wait_for_overlap);

				BUG_ON(sh->dev[i].written);
				sh->dev[i].written = chosen;
			}
		break;
	case CHECK_PARITY:
		BUG();		/* Not implemented yet */
	}

	for (i = disks; i--;)
		if (sh->dev[i].written) {
			sector_t sector = sh->dev[i].sector;
			struct bio *wbi = sh->dev[i].written;
			while (wbi && wbi->bi_sector < sector + STRIPE_SECTORS) {
				copy_data(1, wbi, sh->dev[i].page, sector);
				wbi = r5_next_bio(wbi, sector);
			}

			set_bit(R5_LOCKED, &sh->dev[i].flags);
			set_bit(R5_UPTODATE, &sh->dev[i].flags);
		}

	/* Note that unlike RAID-5, the ordering of the disks matters greatly.*/

	for (i = 0; i < disks; i++)
		ptrs[i] = (void *)raid6_empty_zero_page;

	count = 0;
	i = d0_idx;
	do {
		int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);

		ptrs[slot] = page_address(sh->dev[i].page);
		if (slot < syndrome_disks &&
		    !test_bit(R5_UPTODATE, &sh->dev[i].flags)) {
			printk(KERN_ERR "block %d/%d not uptodate "
			       "on parity calc\n", i, count);
			BUG();
		}

		i = raid6_next_disk(i, disks);
	} while (i != d0_idx);
	BUG_ON(count != syndrome_disks);

	raid6_call.gen_syndrome(syndrome_disks+2, STRIPE_SIZE, ptrs);

	switch(method) {
	case RECONSTRUCT_WRITE:
		set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
		set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
		set_bit(R5_LOCKED,   &sh->dev[pd_idx].flags);
		set_bit(R5_LOCKED,   &sh->dev[qd_idx].flags);
		break;
	case UPDATE_PARITY:
		set_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
		set_bit(R5_UPTODATE, &sh->dev[qd_idx].flags);
		break;
	}
}


/* Compute one missing block */
static void compute_block_1(struct stripe_head *sh, int dd_idx, int nozero)
{
	int i, count, disks = sh->disks;
	void *ptr[MAX_XOR_BLOCKS], *dest, *p;
	int qd_idx = sh->qd_idx;

	pr_debug("compute_block_1, stripe %llu, idx %d\n",
		(unsigned long long)sh->sector, dd_idx);

	if ( dd_idx == qd_idx ) {
		/* We're actually computing the Q drive */
		compute_parity6(sh, UPDATE_PARITY);
	} else {
		dest = page_address(sh->dev[dd_idx].page);
		if (!nozero) memset(dest, 0, STRIPE_SIZE);
		count = 0;
		for (i = disks ; i--; ) {
			if (i == dd_idx || i == qd_idx)
				continue;
			p = page_address(sh->dev[i].page);
			if (test_bit(R5_UPTODATE, &sh->dev[i].flags))
				ptr[count++] = p;
			else
				printk("compute_block() %d, stripe %llu, %d"
				       " not present\n", dd_idx,
				       (unsigned long long)sh->sector, i);

			check_xor();
		}
		if (count)
			xor_blocks(count, STRIPE_SIZE, dest, ptr);
		if (!nozero) set_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
		else clear_bit(R5_UPTODATE, &sh->dev[dd_idx].flags);
	}
}

/* Compute two missing blocks */
static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
{
	int i, count, disks = sh->disks;
	int syndrome_disks = sh->ddf_layout ? disks : disks-2;
	int d0_idx = raid6_d0(sh);
	int faila = -1, failb = -1;
	/**** FIX THIS: This could be very bad if disks is close to 256 ****/
	void *ptrs[syndrome_disks+2];

	for (i = 0; i < disks ; i++)
		ptrs[i] = (void *)raid6_empty_zero_page;
	count = 0;
	i = d0_idx;
	do {
		int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);

		ptrs[slot] = page_address(sh->dev[i].page);

		if (i == dd_idx1)
			faila = slot;
		if (i == dd_idx2)
			failb = slot;
		i = raid6_next_disk(i, disks);
	} while (i != d0_idx);
	BUG_ON(count != syndrome_disks);

	BUG_ON(faila == failb);
	if ( failb < faila ) { int tmp = faila; faila = failb; failb = tmp; }

	pr_debug("compute_block_2, stripe %llu, idx %d,%d (%d,%d)\n",
		 (unsigned long long)sh->sector, dd_idx1, dd_idx2,
		 faila, failb);

	if (failb == syndrome_disks+1) {
		/* Q disk is one of the missing disks */
		if (faila == syndrome_disks) {
			/* Missing P+Q, just recompute */
			compute_parity6(sh, UPDATE_PARITY);
			return;
		} else {
			/* We're missing D+Q; recompute D from P */
			compute_block_1(sh, ((dd_idx1 == sh->qd_idx) ?
					     dd_idx2 : dd_idx1),
					0);
			compute_parity6(sh, UPDATE_PARITY); /* Is this necessary? */
			return;
		}
	}

	/* We're missing D+P or D+D; */
	if (failb == syndrome_disks) {
		/* We're missing D+P. */
		raid6_datap_recov(syndrome_disks+2, STRIPE_SIZE, faila, ptrs);
	} else {
		/* We're missing D+D. */
		raid6_2data_recov(syndrome_disks+2, STRIPE_SIZE, faila, failb,
				  ptrs);
	}

	/* Both the above update both missing blocks */
	set_bit(R5_UPTODATE, &sh->dev[dd_idx1].flags);
	set_bit(R5_UPTODATE, &sh->dev[dd_idx2].flags);
}

static void
schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
			 int rcw, int expand)
@@ -2331,13 +2084,6 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in

static void end_reshape(raid5_conf_t *conf);

static int page_is_zero(struct page *p)
{
	char *a = page_address(p);
	return ((*(u32*)a) == 0 &&
		memcmp(a, a+4, STRIPE_SIZE-4)==0);
}

static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous,
			    struct stripe_head *sh)
{