Skip to content

Commit

Permalink
raid5: use flex_array for scribble data
Browse files Browse the repository at this point in the history 
Use flex_array for scribble data. Next patch will batch several stripes
together, so scribble data should be able to cover several stripes, so this
patch also allocates scribble data for stripes across a chunk.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
  • Loading branch information
shli@kernel.org authored and NeilBrown committed Apr 21, 2015
1 parent 753f285 commit 46d5b78
Show file tree
Hide file tree
Showing 2 changed files with 57 additions and 38 deletions.
89 changes: 56 additions & 33 deletions drivers/md/raid5.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,7 @@
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/nodemask.h>
#include <linux/flex_array.h>
#include <trace/events/block.h>

#include "md.h"
Expand Down Expand Up @@ -1109,16 +1110,28 @@ static void ops_complete_compute(void *stripe_head_ref)

/* return a pointer to the address conversion region of the scribble buffer */
static addr_conv_t *to_addr_conv(struct stripe_head *sh,
struct raid5_percpu *percpu)
struct raid5_percpu *percpu, int i)
{
return percpu->scribble + sizeof(struct page *) * (sh->disks + 2);
void *addr;

addr = flex_array_get(percpu->scribble, i);
return addr + sizeof(struct page *) * (sh->disks + 2);
}

/* return a pointer to the address conversion region of the scribble buffer */
static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
{
void *addr;

addr = flex_array_get(percpu->scribble, i);
return addr;
}

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 = percpu->scribble;
struct page **xor_srcs = to_addr_page(percpu, 0);
int target = sh->ops.target;
struct r5dev *tgt = &sh->dev[target];
struct page *xor_dest = tgt->page;
Expand All @@ -1138,7 +1151,7 @@ ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
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));
ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
else
Expand Down Expand Up @@ -1183,7 +1196,7 @@ static struct dma_async_tx_descriptor *
ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
{
int disks = sh->disks;
struct page **blocks = percpu->scribble;
struct page **blocks = to_addr_page(percpu, 0);
int target;
int qd_idx = sh->qd_idx;
struct dma_async_tx_descriptor *tx;
Expand Down Expand Up @@ -1216,7 +1229,7 @@ ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
BUG_ON(blocks[count+1] != dest); /* q should already be set */
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
} else {
/* Compute any data- or p-drive using XOR */
Expand All @@ -1229,7 +1242,7 @@ ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)

init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
NULL, ops_complete_compute, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
}

Expand All @@ -1248,7 +1261,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
struct r5dev *tgt = &sh->dev[target];
struct r5dev *tgt2 = &sh->dev[target2];
struct dma_async_tx_descriptor *tx;
struct page **blocks = percpu->scribble;
struct page **blocks = to_addr_page(percpu, 0);
struct async_submit_ctl submit;

pr_debug("%s: stripe %llu block1: %d block2: %d\n",
Expand Down Expand Up @@ -1290,7 +1303,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
/* Missing P+Q, just recompute */
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
return async_gen_syndrome(blocks, 0, syndrome_disks+2,
STRIPE_SIZE, &submit);
} else {
Expand All @@ -1314,21 +1327,21 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
init_async_submit(&submit,
ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
NULL, NULL, NULL,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
&submit);

count = set_syndrome_sources(blocks, sh);
init_async_submit(&submit, ASYNC_TX_FENCE, tx,
ops_complete_compute, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
return async_gen_syndrome(blocks, 0, count+2,
STRIPE_SIZE, &submit);
}
} else {
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
if (failb == syndrome_disks) {
/* We're missing D+P. */
return async_raid6_datap_recov(syndrome_disks+2,
Expand Down Expand Up @@ -1356,7 +1369,7 @@ ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs = percpu->scribble;
struct page **xor_srcs = to_addr_page(percpu, 0);
int count = 0, pd_idx = sh->pd_idx, i;
struct async_submit_ctl submit;

Expand All @@ -1374,7 +1387,7 @@ ops_run_prexor(struct stripe_head *sh, struct raid5_percpu *percpu,
}

init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
ops_complete_prexor, sh, to_addr_conv(sh, percpu));
ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);

return tx;
Expand Down Expand Up @@ -1478,7 +1491,7 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs = percpu->scribble;
struct page **xor_srcs = to_addr_page(percpu, 0);
struct async_submit_ctl submit;
int count = 0, pd_idx = sh->pd_idx, i;
struct page *xor_dest;
Expand Down Expand Up @@ -1531,7 +1544,7 @@ ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
atomic_inc(&sh->count);

init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
else
Expand All @@ -1543,7 +1556,7 @@ ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
struct async_submit_ctl submit;
struct page **blocks = percpu->scribble;
struct page **blocks = to_addr_page(percpu, 0);
int count, i;

pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
Expand All @@ -1567,7 +1580,7 @@ ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
atomic_inc(&sh->count);

init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
sh, to_addr_conv(sh, percpu));
sh, to_addr_conv(sh, percpu, 0));
async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
}

Expand All @@ -1589,7 +1602,7 @@ static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
struct page *xor_dest;
struct page **xor_srcs = percpu->scribble;
struct page **xor_srcs = to_addr_page(percpu, 0);
struct dma_async_tx_descriptor *tx;
struct async_submit_ctl submit;
int count;
Expand All @@ -1608,7 +1621,7 @@ static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
}

init_async_submit(&submit, 0, NULL, NULL, NULL,
to_addr_conv(sh, percpu));
to_addr_conv(sh, percpu, 0));
tx = async_xor_val(xor_dest, xor_srcs, 0, count, STRIPE_SIZE,
&sh->ops.zero_sum_result, &submit);

Expand All @@ -1619,7 +1632,7 @@ static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)

static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
{
struct page **srcs = percpu->scribble;
struct page **srcs = to_addr_page(percpu, 0);
struct async_submit_ctl submit;
int count;

Expand All @@ -1632,7 +1645,7 @@ static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu

atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
sh, to_addr_conv(sh, percpu));
sh, to_addr_conv(sh, percpu, 0));
async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
&sh->ops.zero_sum_result, percpu->spare_page, &submit);
}
Expand Down Expand Up @@ -1772,13 +1785,21 @@ static int grow_stripes(struct r5conf *conf, int num)
* calculate over all devices (not just the data blocks), using zeros in place
* of the P and Q blocks.
*/
static size_t scribble_len(int num)
static struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags)
{
struct flex_array *ret;
size_t len;

len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);

return len;
ret = flex_array_alloc(len, cnt, flags);
if (!ret)
return NULL;
/* always prealloc all elements, so no locking is required */
if (flex_array_prealloc(ret, 0, cnt, flags)) {
flex_array_free(ret);
return NULL;
}
return ret;
}

static int resize_stripes(struct r5conf *conf, int newsize)
Expand Down Expand Up @@ -1896,16 +1917,16 @@ static int resize_stripes(struct r5conf *conf, int newsize)
err = -ENOMEM;

get_online_cpus();
conf->scribble_len = scribble_len(newsize);
for_each_present_cpu(cpu) {
struct raid5_percpu *percpu;
void *scribble;
struct flex_array *scribble;

percpu = per_cpu_ptr(conf->percpu, cpu);
scribble = kmalloc(conf->scribble_len, GFP_NOIO);
scribble = scribble_alloc(newsize, conf->chunk_sectors /
STRIPE_SECTORS, GFP_NOIO);

if (scribble) {
kfree(percpu->scribble);
flex_array_free(percpu->scribble);
percpu->scribble = scribble;
} else {
err = -ENOMEM;
Expand Down Expand Up @@ -5698,7 +5719,8 @@ raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
{
safe_put_page(percpu->spare_page);
kfree(percpu->scribble);
if (percpu->scribble)
flex_array_free(percpu->scribble);
percpu->spare_page = NULL;
percpu->scribble = NULL;
}
Expand All @@ -5708,7 +5730,9 @@ static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu
if (conf->level == 6 && !percpu->spare_page)
percpu->spare_page = alloc_page(GFP_KERNEL);
if (!percpu->scribble)
percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
percpu->scribble = scribble_alloc(max(conf->raid_disks,
conf->previous_raid_disks), conf->chunk_sectors /
STRIPE_SECTORS, GFP_KERNEL);

if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
free_scratch_buffer(conf, percpu);
Expand Down Expand Up @@ -5878,7 +5902,6 @@ static struct r5conf *setup_conf(struct mddev *mddev)
else
conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
max_disks = max(conf->raid_disks, conf->previous_raid_disks);
conf->scribble_len = scribble_len(max_disks);

conf->disks = kzalloc(max_disks * sizeof(struct disk_info),
GFP_KERNEL);
Expand Down Expand Up @@ -5906,6 +5929,7 @@ static struct r5conf *setup_conf(struct mddev *mddev)
INIT_LIST_HEAD(conf->temp_inactive_list + i);

conf->level = mddev->new_level;
conf->chunk_sectors = mddev->new_chunk_sectors;
if (raid5_alloc_percpu(conf) != 0)
goto abort;

Expand Down Expand Up @@ -5938,7 +5962,6 @@ static struct r5conf *setup_conf(struct mddev *mddev)
conf->fullsync = 1;
}

conf->chunk_sectors = mddev->new_chunk_sectors;
conf->level = mddev->new_level;
if (conf->level == 6)
conf->max_degraded = 2;
Expand Down
6 changes: 1 addition & 5 deletions drivers/md/raid5.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -458,15 +458,11 @@ struct r5conf {
/* per cpu variables */
struct raid5_percpu {
struct page *spare_page; /* Used when checking P/Q in raid6 */
void *scribble; /* space for constructing buffer
struct flex_array *scribble; /* space for constructing buffer
* lists and performing address
* conversions
*/
} __percpu *percpu;
size_t scribble_len; /* size of scribble region must be
* associated with conf to handle
* cpu hotplug while reshaping
*/
#ifdef CONFIG_HOTPLUG_CPU
struct notifier_block cpu_notify;
#endif
Expand Down

0 comments on commit 46d5b78

Please sign in to comment.