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md/raid5: add a new member of offset into r5dev
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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: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
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Yufen Yu authored and Song Liu committed Sep 24, 2020
1 parent 313b825 commit 7aba13b
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Showing 2 changed files with 40 additions and 11 deletions.
50 changes: 39 additions & 11 deletions drivers/md/raid5.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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,
Expand Down Expand Up @@ -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;
Expand All @@ -1881,24 +1898,31 @@ 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;
}
}
}

Expand All @@ -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,
Expand Down Expand Up @@ -2253,8 +2277,9 @@ static int scribble_alloc(struct raid5_percpu *percpu,
int num, int cnt)
{
size_t obj_size =
sizeof(struct page *) * (num+2) +
sizeof(addr_conv_t) * (num+2);
sizeof(struct page *) * (num + 2) +
sizeof(addr_conv_t) * (num + 2) +
sizeof(unsigned int) * (num + 2);
void *scribble;

/*
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
}
Expand Down Expand Up @@ -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);
Expand Down
1 change: 1 addition & 0 deletions drivers/md/raid5.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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