Commit 7aba13b7 authored by Yufen Yu's avatar Yufen Yu Committed by Song Liu
Browse files

md/raid5: add a new member of offset into r5dev 



Add a new member of offset into struct r5dev. It indicates the
offset of related dev[i].page. For now, since each device have a
privated page, the value is always 0. Thus, we set offset as 0
when allcate page in grow_buffers() and resize_stripes().

To support following different page offset, we try to use the page
offset rather than '0' directly for async_memcpy() and ops_run_io().

We try to support different page offset for xor compution functions
in the following. To avoid repeatly allocate a new array each time,
we add a memory region into scribble buffer to record offset.

No functional change.

Signed-off-by: default avatarYufen Yu <yuyufen@huawei.com>
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
parent 313b825f

drivers/md/raid5.c

+39 −11
Original line number Diff line number Diff line
@@ -477,6 +477,7 @@ static int grow_buffers(struct stripe_head *sh, gfp_t gfp) 
		}

		sh->dev[i].page = page;

		sh->dev[i].orig_page = page;

		sh->dev[i].offset = 0;

	}



	return 0;
@@ -1130,7 +1131,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 
				sh->dev[i].vec.bv_page = sh->dev[i].page;

			bi->bi_vcnt = 1;

			bi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);

			bi->bi_io_vec[0].bv_offset = 0;

			bi->bi_io_vec[0].bv_offset = sh->dev[i].offset;

			bi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);

			bi->bi_write_hint = sh->dev[i].write_hint;

			if (!rrdev)
@@ -1184,7 +1185,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) 
			sh->dev[i].rvec.bv_page = sh->dev[i].page;

			rbi->bi_vcnt = 1;

			rbi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);

			rbi->bi_io_vec[0].bv_offset = 0;

			rbi->bi_io_vec[0].bv_offset = sh->dev[i].offset;

			rbi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);

			rbi->bi_write_hint = sh->dev[i].write_hint;

			sh->dev[i].write_hint = RWH_WRITE_LIFE_NOT_SET;
@@ -1404,14 +1405,25 @@ static addr_conv_t *to_addr_conv(struct stripe_head *sh, 
	return (void *) (to_addr_page(percpu, i) + sh->disks + 2);

}



/*

 * Return a pointer to record offset address.

 */

static unsigned int *

to_addr_offs(struct stripe_head *sh, struct raid5_percpu *percpu)

{

	return (unsigned int *) (to_addr_conv(sh, percpu, 0) + sh->disks + 2);

}



static struct dma_async_tx_descriptor *

ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)

{

	int disks = sh->disks;

	struct page **xor_srcs = to_addr_page(percpu, 0);

	unsigned int *off_srcs = to_addr_offs(sh, percpu);

	int target = sh->ops.target;

	struct r5dev *tgt = &sh->dev[target];

	struct page *xor_dest = tgt->page;

	unsigned int off_dest = tgt->offset;

	int count = 0;

	struct dma_async_tx_descriptor *tx;

	struct async_submit_ctl submit;
@@ -1423,16 +1435,19 @@ ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 
		__func__, (unsigned long long)sh->sector, target);

	BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));



	for (i = disks; i--; )

		if (i != target)

	for (i = disks; i--; ) {

		if (i != target) {

			off_srcs[count] = sh->dev[i].offset;

			xor_srcs[count++] = sh->dev[i].page;

		}

	}



	atomic_inc(&sh->count);



	init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,

			  ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));

	if (unlikely(count == 1))

		tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0,

		tx = async_memcpy(xor_dest, xor_srcs[0], off_dest, off_srcs[0],

				RAID5_STRIPE_SIZE(sh->raid_conf), &submit);

	else

		tx = async_xor(xor_dest, xor_srcs, 0, count,
@@ -1854,9 +1869,11 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 
{

	int disks = sh->disks;

	struct page **xor_srcs;

	unsigned int *off_srcs;

	struct async_submit_ctl submit;

	int count, pd_idx = sh->pd_idx, i;

	struct page *xor_dest;

	unsigned int off_dest;

	int prexor = 0;

	unsigned long flags;

	int j = 0;
@@ -1881,26 +1898,33 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 
again:

	count = 0;

	xor_srcs = to_addr_page(percpu, j);

	off_srcs = to_addr_offs(sh, percpu);

	/* check if prexor is active which means only process blocks

	 * that are part of a read-modify-write (written)

	 */

	if (head_sh->reconstruct_state == reconstruct_state_prexor_drain_run) {

		prexor = 1;

		off_dest = off_srcs[count] = sh->dev[pd_idx].offset;

		xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;

		for (i = disks; i--; ) {

			struct r5dev *dev = &sh->dev[i];

			if (head_sh->dev[i].written ||

			    test_bit(R5_InJournal, &head_sh->dev[i].flags))

			    test_bit(R5_InJournal, &head_sh->dev[i].flags)) {

				off_srcs[count] = dev->offset;

				xor_srcs[count++] = dev->page;

			}

		}

	} else {

		xor_dest = sh->dev[pd_idx].page;

		off_dest = sh->dev[pd_idx].offset;

		for (i = disks; i--; ) {

			struct r5dev *dev = &sh->dev[i];

			if (i != pd_idx)

			if (i != pd_idx) {

				off_srcs[count] = dev->offset;

				xor_srcs[count++] = dev->page;

			}

		}

	}



	/* 1/ if we prexor'd then the dest is reused as a source

	 * 2/ if we did not prexor then we are redoing the parity
@@ -1924,7 +1948,7 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu, 
	}



	if (unlikely(count == 1))

		tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0,

		tx = async_memcpy(xor_dest, xor_srcs[0], off_dest, off_srcs[0],

				RAID5_STRIPE_SIZE(sh->raid_conf), &submit);

	else

		tx = async_xor(xor_dest, xor_srcs, 0, count,
@@ -2254,7 +2278,8 @@ static int scribble_alloc(struct raid5_percpu *percpu, 
{

	size_t obj_size =

		sizeof(struct page *) * (num + 2) +

		sizeof(addr_conv_t) * (num+2);

		sizeof(addr_conv_t) * (num + 2) +

		sizeof(unsigned int) * (num + 2);

	void *scribble;



	/*
@@ -2389,6 +2414,7 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
		for(i=0; i<conf->pool_size; i++) {

			nsh->dev[i].page = osh->dev[i].page;

			nsh->dev[i].orig_page = osh->dev[i].page;

			nsh->dev[i].offset = osh->dev[i].offset;

		}

		nsh->hash_lock_index = hash;

		free_stripe(conf->slab_cache, osh);
@@ -2444,6 +2470,7 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
				struct page *p = alloc_page(GFP_NOIO);

				nsh->dev[i].page = p;

				nsh->dev[i].orig_page = p;

				nsh->dev[i].offset = 0;

				if (!p)

					err = -ENOMEM;

			}
@@ -4369,7 +4396,8 @@ static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh) 
			/* place all the copies on one channel */

			init_async_submit(&submit, 0, tx, NULL, NULL, NULL);

			tx = async_memcpy(sh2->dev[dd_idx].page,

					  sh->dev[i].page, 0, 0, RAID5_STRIPE_SIZE(conf),

					  sh->dev[i].page, sh2->dev[dd_idx].offset,

					  sh->dev[i].offset, RAID5_STRIPE_SIZE(conf),

					  &submit);



			set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);

drivers/md/raid5.h

+1 −0
Original line number Diff line number Diff line
@@ -253,6 +253,7 @@ struct stripe_head { 
		struct bio	req, rreq;

		struct bio_vec	vec, rvec;

		struct page	*page, *orig_page;

		unsigned int    offset;     /* offset of the page */

		struct bio	*toread, *read, *towrite, *written;

		sector_t	sector;			/* sector of this page */

		unsigned long	flags;