* [PATCH 1/8] md/raid5: factor out mark_uptodate from ops_complete_compute5
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 1:29 ` [PATCH 2/8] md/raid6: asynchronous raid6 operations Dan Williams
` (6 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, yur
ops_complete_compute5 can be reused in the raid6 path if it is updated to
generically handle a second target.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 48aa114..45eeefd 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -651,18 +651,29 @@ static void ops_run_biofill(struct stripe_head *sh)
async_trigger_callback(&submit);
}
+static void mark_target_uptodate(struct stripe_head *sh, int target)
+{
+ struct r5dev *tgt;
+
+ if (target < 0)
+ return;
+
+ tgt = &sh->dev[target];
+ set_bit(R5_UPTODATE, &tgt->flags);
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
+ clear_bit(R5_Wantcompute, &tgt->flags);
+}
+
static void ops_complete_compute5(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
- int target = sh->ops.target;
- struct r5dev *tgt = &sh->dev[target];
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
- set_bit(R5_UPTODATE, &tgt->flags);
- BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
- clear_bit(R5_Wantcompute, &tgt->flags);
+ /* mark the computed target as uptodate */
+ mark_target_uptodate(sh, sh->ops.target);
+
clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
if (sh->check_state == check_state_compute_run)
sh->check_state = check_state_compute_result;
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 2/8] md/raid6: asynchronous raid6 operations
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
2009-06-04 1:29 ` [PATCH 1/8] md/raid5: factor out mark_uptodate from ops_complete_compute5 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 6:33 ` Neil Brown
2009-06-04 1:29 ` [PATCH 3/8] md/raid5,6: common schedule_reconstruction for raid5/6 Dan Williams
` (5 subsequent siblings)
7 siblings, 1 reply; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Andre Noll, Ilya Yanok, Yuri Tikhonov
[ Based on an original patch by Yuri Tikhonov ]
The raid_run_ops routine uses the asynchronous offload api and
the stripe_operations member of a stripe_head to carry out xor+pq+copy
operations asynchronously, outside the lock.
The operations performed by RAID-6 are the same as in the RAID-5 case
except for no support of STRIPE_OP_PREXOR operations. All the others
are supported:
STRIPE_OP_BIOFILL
- copy data into request buffers to satisfy a read request
STRIPE_OP_COMPUTE_BLK
- generate missing blocks (1 or 2) in the cache from the other blocks
STRIPE_OP_BIODRAIN
- copy data out of request buffers to satisfy a write request
STRIPE_OP_RECONSTRUCT
- recalculate parity for new data that has entered the cache
STRIPE_OP_CHECK
- verify that the parity is correct
The flow is the same as in the RAID-5 case, and reuses some routines, namely:
1/ ops_complete_postxor (renamed to ops_complete_reconstruct)
2/ ops_complete_compute (updated to set up to 2 targets uptodate)
3/ ops_run_check (renamed to ops_run_check_p for xor parity checks)
[neilb@suse.de: fixes to get it to pass mdadm regression suite]
Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/Kconfig | 2
drivers/md/raid5.c | 319 +++++++++++++++++++++++++++++++++++++++++++++++-----
drivers/md/raid5.h | 8 +
3 files changed, 297 insertions(+), 32 deletions(-)
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 41b3ae2..db3ef83 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -124,6 +124,8 @@ config MD_RAID456
select MD_RAID6_PQ
select ASYNC_MEMCPY
select ASYNC_XOR
+ select ASYNC_PQ
+ select ASYNC_R6RECOV
---help---
A RAID-5 set of N drives with a capacity of C MB per drive provides
the capacity of C * (N - 1) MB, and protects against a failure
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 45eeefd..acf1c12 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -664,15 +664,16 @@ static void mark_target_uptodate(struct stripe_head *sh, int target)
clear_bit(R5_Wantcompute, &tgt->flags);
}
-static void ops_complete_compute5(void *stripe_head_ref)
+static void ops_complete_compute(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
- /* mark the computed target as uptodate */
+ /* mark the computed target(s) as uptodate */
mark_target_uptodate(sh, sh->ops.target);
+ mark_target_uptodate(sh, sh->ops.target2);
clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
if (sh->check_state == check_state_compute_run)
@@ -715,7 +716,7 @@ static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh)
atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL,
- ops_complete_compute5, sh, sh_to_addr_conv(sh));
+ ops_complete_compute, sh, sh_to_addr_conv(sh));
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
else
@@ -724,6 +725,197 @@ static struct dma_async_tx_descriptor *ops_run_compute5(struct stripe_head *sh)
return tx;
}
+/* set_syndrome_sources - populate source buffers for gen_syndrome
+ * @srcs - (struct page *) array of size sh->disks
+ * @sh - stripe_head to parse
+ *
+ * Populates srcs in proper layout order for the stripe and returns the
+ * 'count' of sources to be used in a call to async_gen_syndrome. The P
+ * destination buffer is recorded in srcs[count] and the Q destination
+ * is recorded in srcs[count+1]].
+ */
+static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
+{
+ int disks = sh->disks;
+ int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
+ int d0_idx = raid6_d0(sh);
+ int count;
+ int i;
+
+ for (i = 0; i < disks; i++)
+ srcs[i] = (void *)raid6_empty_zero_page;
+
+ count = 0;
+ i = d0_idx;
+ do {
+ int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
+
+ srcs[slot] = sh->dev[i].page;
+ i = raid6_next_disk(i, disks);
+ } while (i != d0_idx);
+ BUG_ON(count != syndrome_disks);
+
+ return count;
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_compute6_1(struct stripe_head *sh)
+{
+ int disks = sh->disks;
+ struct page **blocks = sh->scribble;
+ int target;
+ int qd_idx = sh->qd_idx;
+ struct dma_async_tx_descriptor *tx;
+ struct async_submit_ctl submit;
+ struct r5dev *tgt;
+ struct page *dest;
+ int i;
+ int count;
+
+ if (sh->ops.target < 0)
+ target = sh->ops.target2;
+ else if (sh->ops.target2 < 0)
+ target = sh->ops.target;
+ else
+ /* we should only have one valid target */
+ BUG();
+ BUG_ON(target < 0);
+ pr_debug("%s: stripe %llu block: %d\n",
+ __func__, (unsigned long long)sh->sector, target);
+
+ tgt = &sh->dev[target];
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
+ dest = tgt->page;
+
+ atomic_inc(&sh->count);
+
+ if (target == qd_idx) {
+ count = set_syndrome_sources(blocks, sh);
+ blocks[count] = NULL; /* regenerating p is not necessary */
+ BUG_ON(blocks[count+1] != dest); /* q should already be set */
+ init_async_submit(&submit, 0, NULL, ops_complete_compute, sh,
+ sh_to_addr_conv(sh));
+ tx = async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
+ } else {
+ /* Compute any data- or p-drive using XOR */
+ count = 0;
+ for (i = disks; i-- ; ) {
+ if (i == target || i == qd_idx)
+ continue;
+ blocks[count++] = sh->dev[i].page;
+ }
+
+ init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL,
+ ops_complete_compute, sh,
+ sh_to_addr_conv(sh));
+ tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE, &submit);
+ }
+
+ return tx;
+}
+
+static struct dma_async_tx_descriptor *
+ops_run_compute6_2(struct stripe_head *sh)
+{
+ 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;
+ int target = sh->ops.target;
+ int target2 = sh->ops.target2;
+ struct r5dev *tgt = &sh->dev[target];
+ struct r5dev *tgt2 = &sh->dev[target2];
+ struct dma_async_tx_descriptor *tx;
+ struct page **blocks = sh->scribble;
+ struct async_submit_ctl submit;
+
+ pr_debug("%s: stripe %llu block1: %d block2: %d\n",
+ __func__, (unsigned long long)sh->sector, target, target2);
+ BUG_ON(target < 0 || target2 < 0);
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
+ BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
+
+ /* we need to open-code set_syndrome_sources to handle to the
+ * slot number conversion for 'faila' and 'failb'
+ */
+ for (i = 0; i < disks ; i++)
+ blocks[i] = (void *)raid6_empty_zero_page;
+ count = 0;
+ i = d0_idx;
+ do {
+ int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
+
+ blocks[slot] = sh->dev[i].page;
+
+ if (i == target)
+ faila = slot;
+ if (i == target2)
+ failb = slot;
+ i = raid6_next_disk(i, disks);
+ } while (i != d0_idx);
+ BUG_ON(count != syndrome_disks);
+
+ BUG_ON(faila == failb);
+ if (failb < faila)
+ swap(faila, failb);
+ pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
+ __func__, (unsigned long long)sh->sector, faila, failb);
+
+ atomic_inc(&sh->count);
+
+ if (failb == syndrome_disks+1) {
+ /* Q disk is one of the missing disks */
+ if (faila == syndrome_disks) {
+ /* Missing P+Q, just recompute */
+ init_async_submit(&submit, 0, NULL, ops_complete_compute,
+ sh, sh_to_addr_conv(sh));
+ return async_gen_syndrome(blocks, 0, count+2,
+ STRIPE_SIZE, &submit);
+ } else {
+ struct page *dest;
+ int data_target;
+ int qd_idx = sh->qd_idx;
+
+ /* Missing D+Q: recompute D from P, then recompute Q */
+ if (target == qd_idx)
+ data_target = target2;
+ else
+ data_target = target;
+
+ count = 0;
+ for (i = disks; i-- ; ) {
+ if (i == data_target || i == qd_idx)
+ continue;
+ blocks[count++] = sh->dev[i].page;
+ }
+ dest = sh->dev[data_target].page;
+ init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL,
+ NULL, NULL, sh_to_addr_conv(sh));
+ tx = async_xor(dest, blocks, 0, count, STRIPE_SIZE,
+ &submit);
+
+ count = set_syndrome_sources(blocks, sh);
+ init_async_submit(&submit, 0, tx, ops_complete_compute,
+ sh, sh_to_addr_conv(sh));
+ return async_gen_syndrome(blocks, 0, count+2,
+ STRIPE_SIZE, &submit);
+ }
+ }
+
+ init_async_submit(&submit, 0, NULL, ops_complete_compute, sh,
+ sh_to_addr_conv(sh));
+ if (failb == syndrome_disks) {
+ /* We're missing D+P. */
+ return async_raid6_datap_recov(syndrome_disks+2, STRIPE_SIZE,
+ faila, blocks, &submit);
+ } else {
+ /* We're missing D+D. */
+ return async_raid6_2data_recov(syndrome_disks+2, STRIPE_SIZE,
+ faila, failb, blocks, &submit);
+ }
+}
+
+
static void ops_complete_prexor(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
@@ -795,17 +987,21 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
return tx;
}
-static void ops_complete_postxor(void *stripe_head_ref)
+static void ops_complete_reconstruct(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
- int disks = sh->disks, i, pd_idx = sh->pd_idx;
+ int disks = sh->disks;
+ int pd_idx = sh->pd_idx;
+ int qd_idx = sh->qd_idx;
+ int i;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- if (dev->written || i == pd_idx)
+
+ if (dev->written || i == pd_idx || i == qd_idx)
set_bit(R5_UPTODATE, &dev->flags);
}
@@ -823,7 +1019,7 @@ static void ops_complete_postxor(void *stripe_head_ref)
}
static void
-ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+ops_run_reconstruct5(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs = sh->scribble;
@@ -866,7 +1062,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
atomic_inc(&sh->count);
- init_async_submit(&submit, flags, tx, ops_complete_postxor, sh,
+ init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh,
sh_to_addr_conv(sh));
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit);
@@ -874,6 +1070,24 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit);
}
+static void
+ops_run_reconstruct6(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+{
+ struct async_submit_ctl submit;
+ struct page **blocks = sh->scribble;
+ int count;
+
+ pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
+
+ count = set_syndrome_sources(blocks, sh);
+
+ atomic_inc(&sh->count);
+
+ init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_reconstruct,
+ sh, sh_to_addr_conv(sh));
+ async_gen_syndrome(blocks, 0, count+2, STRIPE_SIZE, &submit);
+}
+
static void ops_complete_check(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
@@ -886,23 +1100,28 @@ static void ops_complete_check(void *stripe_head_ref)
release_stripe(sh);
}
-static void ops_run_check(struct stripe_head *sh)
+static void ops_run_check_p(struct stripe_head *sh)
{
int disks = sh->disks;
+ int pd_idx = sh->pd_idx;
+ int qd_idx = sh->qd_idx;
+ struct page *xor_dest;
struct page **xor_srcs = sh->scribble;
struct dma_async_tx_descriptor *tx;
struct async_submit_ctl submit;
-
- int count = 0, pd_idx = sh->pd_idx, i;
- struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
+ int count;
+ int i;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
+ count = 0;
+ xor_dest = sh->dev[pd_idx].page;
+ xor_srcs[count++] = xor_dest;
for (i = disks; i--; ) {
- struct r5dev *dev = &sh->dev[i];
- if (i != pd_idx)
- xor_srcs[count++] = dev->page;
+ if (i == pd_idx || i == qd_idx)
+ continue;
+ xor_srcs[count++] = sh->dev[i].page;
}
init_async_submit(&submit, 0, NULL, NULL, NULL, sh_to_addr_conv(sh));
@@ -914,9 +1133,30 @@ static void ops_run_check(struct stripe_head *sh)
tx = async_trigger_callback(&submit);
}
-static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
+static void ops_run_check_pq(struct stripe_head *sh, int checkp)
+{
+ struct page **srcs = sh->scribble;
+ struct async_submit_ctl submit;
+ int count;
+
+ pr_debug("%s: stripe %llu checkp: %d\n", __func__,
+ (unsigned long long)sh->sector, checkp);
+
+ count = set_syndrome_sources(srcs, sh);
+ if (!checkp)
+ srcs[count] = NULL;
+
+ atomic_inc(&sh->count);
+ init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
+ sh, sh_to_addr_conv(sh));
+ async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE,
+ &sh->ops.zero_sum_result, &submit);
+}
+
+static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
{
int overlap_clear = 0, i, disks = sh->disks;
+ int level = sh->raid_conf->level;
struct dma_async_tx_descriptor *tx = NULL;
mutex_lock(&sh->scribble_lock);
@@ -926,9 +1166,16 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
}
if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
- tx = ops_run_compute5(sh);
- /* terminate the chain if postxor is not set to be run */
- if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request))
+ if (level < 6)
+ tx = ops_run_compute5(sh);
+ else {
+ if (sh->ops.target2 < 0 || sh->ops.target < 0)
+ tx = ops_run_compute6_1(sh);
+ else
+ tx = ops_run_compute6_2(sh);
+ }
+ /* terminate the chain if reconstruct is not set to be run */
+ if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
async_tx_ack(tx);
}
@@ -940,11 +1187,23 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
overlap_clear++;
}
- if (test_bit(STRIPE_OP_POSTXOR, &ops_request))
- ops_run_postxor(sh, tx);
+ if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
+ if (level < 6)
+ ops_run_reconstruct5(sh, tx);
+ else
+ ops_run_reconstruct6(sh, tx);
+ }
- if (test_bit(STRIPE_OP_CHECK, &ops_request))
- ops_run_check(sh);
+ if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
+ if (sh->check_state == check_state_run)
+ ops_run_check_p(sh);
+ else if (sh->check_state == check_state_run_q)
+ ops_run_check_pq(sh, 0);
+ else if (sh->check_state == check_state_run_pq)
+ ops_run_check_pq(sh, 1);
+ else
+ BUG();
+ }
if (overlap_clear)
for (i = disks; i--; ) {
@@ -1925,7 +2184,7 @@ schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
} else
sh->reconstruct_state = reconstruct_state_run;
- set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
+ set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
@@ -1948,7 +2207,7 @@ schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
sh->reconstruct_state = reconstruct_state_prexor_drain_run;
set_bit(STRIPE_OP_PREXOR, &s->ops_request);
set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
- set_bit(STRIPE_OP_POSTXOR, &s->ops_request);
+ set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
@@ -2200,9 +2459,10 @@ static int fetch_block5(struct stripe_head *sh, struct stripe_head_state *s,
set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
set_bit(R5_Wantcompute, &dev->flags);
sh->ops.target = disk_idx;
+ sh->ops.target2 = -1;
s->req_compute = 1;
/* Careful: from this point on 'uptodate' is in the eye
- * of raid5_run_ops which services 'compute' operations
+ * of raid_run_ops which services 'compute' operations
* before writes. R5_Wantcompute flags a block that will
* be R5_UPTODATE by the time it is needed for a
* subsequent operation.
@@ -2429,8 +2689,8 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
*/
/* since handle_stripe can be called at any time we need to handle the
* case where a compute block operation has been submitted and then a
- * subsequent call wants to start a write request. raid5_run_ops only
- * handles the case where compute block and postxor are requested
+ * subsequent call wants to start a write request. raid_run_ops only
+ * handles the case where compute block and reconstruct are requested
* simultaneously. If this is not the case then new writes need to be
* held off until the compute completes.
*/
@@ -2612,6 +2872,7 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
set_bit(R5_Wantcompute,
&sh->dev[sh->pd_idx].flags);
sh->ops.target = sh->pd_idx;
+ sh->ops.target2 = -1;
s->uptodate++;
}
}
@@ -3063,7 +3324,7 @@ static bool handle_stripe5(struct stripe_head *sh)
md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
if (s.ops_request)
- raid5_run_ops(sh, s.ops_request);
+ raid_run_ops(sh, s.ops_request);
ops_run_io(sh, &s);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index f580cb9..4eb813e 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -176,7 +176,9 @@
*/
enum check_states {
check_state_idle = 0,
- check_state_run, /* parity check */
+ check_state_run, /* xor parity check */
+ check_state_run_q, /* q-parity check */
+ check_state_run_pq, /* pq dual parity check */
check_state_check_result,
check_state_compute_run, /* parity repair */
check_state_compute_result,
@@ -221,7 +223,7 @@ struct stripe_head {
* @target - STRIPE_OP_COMPUTE_BLK target
*/
struct stripe_operations {
- int target;
+ int target, target2;
enum sum_check_flags zero_sum_result;
} ops;
struct r5dev {
@@ -304,7 +306,7 @@ struct r6_state {
#define STRIPE_OP_COMPUTE_BLK 1
#define STRIPE_OP_PREXOR 2
#define STRIPE_OP_BIODRAIN 3
-#define STRIPE_OP_POSTXOR 4
+#define STRIPE_OP_RECONSTRUCT 4
#define STRIPE_OP_CHECK 5
/*
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 2/8] md/raid6: asynchronous raid6 operations
2009-06-04 1:29 ` [PATCH 2/8] md/raid6: asynchronous raid6 operations Dan Williams
@ 2009-06-04 6:33 ` Neil Brown
0 siblings, 0 replies; 11+ messages in thread
From: Neil Brown @ 2009-06-04 6:33 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-raid, Andre Noll, Ilya Yanok, Yuri Tikhonov
On Wednesday June 3, dan.j.williams@intel.com wrote:
> [ Based on an original patch by Yuri Tikhonov ]
>
> The raid_run_ops routine uses the asynchronous offload api and
> the stripe_operations member of a stripe_head to carry out xor+pq+copy
> operations asynchronously, outside the lock.
>
> The operations performed by RAID-6 are the same as in the RAID-5 case
> except for no support of STRIPE_OP_PREXOR operations. All the others
> are supported:
> STRIPE_OP_BIOFILL
> - copy data into request buffers to satisfy a read request
> STRIPE_OP_COMPUTE_BLK
> - generate missing blocks (1 or 2) in the cache from the other blocks
> STRIPE_OP_BIODRAIN
> - copy data out of request buffers to satisfy a write request
> STRIPE_OP_RECONSTRUCT
> - recalculate parity for new data that has entered the cache
> STRIPE_OP_CHECK
> - verify that the parity is correct
>
> The flow is the same as in the RAID-5 case, and reuses some routines, namely:
> 1/ ops_complete_postxor (renamed to ops_complete_reconstruct)
> 2/ ops_complete_compute (updated to set up to 2 targets uptodate)
> 3/ ops_run_check (renamed to ops_run_check_p for xor parity checks)
>
...
> +static struct dma_async_tx_descriptor *
> +ops_run_compute6_1(struct stripe_head *sh)
> +{
> + int disks = sh->disks;
> + struct page **blocks = sh->scribble;
> + int target;
> + int qd_idx = sh->qd_idx;
> + struct dma_async_tx_descriptor *tx;
> + struct async_submit_ctl submit;
> + struct r5dev *tgt;
> + struct page *dest;
> + int i;
> + int count;
> +
> + if (sh->ops.target < 0)
> + target = sh->ops.target2;
> + else if (sh->ops.target2 < 0)
> + target = sh->ops.target;
> + else
> + /* we should only have one valid target */
> + BUG();
> + BUG_ON(target < 0);
This looks wrong.
It seems to suggest that target2 can be >=0 while target < 0
and I don't think it can. So while the code won't actually
malfunction, it is misleading.
Can we just have
target = sh->ops.target;
BUG_ON(target < 0);
BUG_ON(sh->ops.target2 >= 0);
??
> @@ -926,9 +1166,16 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long ops_request)
> }
>
> if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
> - tx = ops_run_compute5(sh);
> - /* terminate the chain if postxor is not set to be run */
> - if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request))
> + if (level < 6)
> + tx = ops_run_compute5(sh);
> + else {
> + if (sh->ops.target2 < 0 || sh->ops.target < 0)
> + tx = ops_run_compute6_1(sh);
> + else
> + tx = ops_run_compute6_2(sh);
> + }
Similarly here.
if (sh->ops.target2 >= 0)
tx = ops_run_compute6_2(sh);
else
tx = ops_run_compute6_1(sh);
And if you add the "count == 1" branch to ops_run_compute6_1,
I think you can use it in place of ops_run_compute5. Then you get
ride of a function, and the above nested ifs becomes a simple:
if (sh->ops.target2 >= 0)
tx = ops_run_compute6_2(sh);
else
tx = ops_run_compute_1(sh);
no need to check the level at all.
Would that be an improvement?
??
NeilBrown
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/8] md/raid5,6: common schedule_reconstruction for raid5/6
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
2009-06-04 1:29 ` [PATCH 1/8] md/raid5: factor out mark_uptodate from ops_complete_compute5 Dan Williams
2009-06-04 1:29 ` [PATCH 2/8] md/raid6: asynchronous raid6 operations Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 1:29 ` [PATCH 4/8] md/raid6: asynchronous handle_stripe_fill6 Dan Williams
` (4 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
From: Yuri Tikhonov <yur@emcraft.com>
Extend schedule_reconstruction5 for reuse by the raid6 path. Add
support for generating Q and BUG() if a request is made to perform
'prexor'.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 24 ++++++++++++++++++------
1 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index acf1c12..3f04d15 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2168,10 +2168,12 @@ static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2)
}
static void
-schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
+schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
int rcw, int expand)
{
int i, pd_idx = sh->pd_idx, disks = sh->disks;
+ raid5_conf_t *conf = sh->raid_conf;
+ int level = conf->level;
if (rcw) {
/* if we are not expanding this is a proper write request, and
@@ -2197,10 +2199,11 @@ schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
s->locked++;
}
}
- if (s->locked + 1 == disks)
+ if (s->locked + conf->max_degraded == disks)
if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
- atomic_inc(&sh->raid_conf->pending_full_writes);
+ atomic_inc(&conf->pending_full_writes);
} else {
+ BUG_ON(level == 6);
BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
@@ -2225,13 +2228,22 @@ schedule_reconstruction5(struct stripe_head *sh, struct stripe_head_state *s,
}
}
- /* keep the parity disk locked while asynchronous operations
+ /* keep the parity disk(s) locked while asynchronous operations
* are in flight
*/
set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
s->locked++;
+ if (level == 6) {
+ int qd_idx = sh->qd_idx;
+ struct r5dev *dev = &sh->dev[qd_idx];
+
+ set_bit(R5_LOCKED, &dev->flags);
+ clear_bit(R5_UPTODATE, &dev->flags);
+ s->locked++;
+ }
+
pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
__func__, (unsigned long long)sh->sector,
s->locked, s->ops_request);
@@ -2697,7 +2709,7 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
(s->locked == 0 && (rcw == 0 || rmw == 0) &&
!test_bit(STRIPE_BIT_DELAY, &sh->state)))
- schedule_reconstruction5(sh, s, rcw == 0, 0);
+ schedule_reconstruction(sh, s, rcw == 0, 0);
}
static void handle_stripe_dirtying6(raid5_conf_t *conf,
@@ -3304,7 +3316,7 @@ static bool handle_stripe5(struct stripe_head *sh)
/* Need to write out all blocks after computing parity */
sh->disks = conf->raid_disks;
stripe_set_idx(sh->sector, conf, 0, sh);
- schedule_reconstruction5(sh, &s, 1, 1);
+ schedule_reconstruction(sh, &s, 1, 1);
} else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 4/8] md/raid6: asynchronous handle_stripe_fill6
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
` (2 preceding siblings ...)
2009-06-04 1:29 ` [PATCH 3/8] md/raid5,6: common schedule_reconstruction for raid5/6 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 6:37 ` Neil Brown
2009-06-04 1:29 ` [PATCH 5/8] md/raid6: asynchronous handle_stripe_dirtying6 Dan Williams
` (3 subsequent siblings)
7 siblings, 1 reply; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
From: Yuri Tikhonov <yur@emcraft.com>
Modify handle_stripe_fill6 to work asynchronously by introducing
fetch_block6 as the raid6 analog of fetch_block5 (schedule compute
operations for missing/out-of-sync disks).
[dan.j.williams@intel.com: compute D+Q in one pass]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 143 ++++++++++++++++++++++++++++++++++------------------
1 files changed, 93 insertions(+), 50 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 3f04d15..836aede 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2513,61 +2513,104 @@ static void handle_stripe_fill5(struct stripe_head *sh,
set_bit(STRIPE_HANDLE, &sh->state);
}
-static void handle_stripe_fill6(struct stripe_head *sh,
- struct stripe_head_state *s, struct r6_state *r6s,
- int disks)
+/* fetch_block6 - checks the given member device to see if its data needs
+ * to be read or computed to satisfy a request.
+ *
+ * Returns 1 when no more member devices need to be checked, otherwise returns
+ * 0 to tell the loop in handle_stripe_fill6 to continue
+ */
+static int fetch_block6(struct stripe_head *sh, struct stripe_head_state *s,
+ struct r6_state *r6s, int disk_idx, int disks)
{
- int i;
- for (i = disks; i--; ) {
- struct r5dev *dev = &sh->dev[i];
- if (!test_bit(R5_LOCKED, &dev->flags) &&
- !test_bit(R5_UPTODATE, &dev->flags) &&
- (dev->toread || (dev->towrite &&
- !test_bit(R5_OVERWRITE, &dev->flags)) ||
- s->syncing || s->expanding ||
- (s->failed >= 1 &&
- (sh->dev[r6s->failed_num[0]].toread ||
- s->to_write)) ||
- (s->failed >= 2 &&
- (sh->dev[r6s->failed_num[1]].toread ||
- s->to_write)))) {
- /* we would like to get this block, possibly
- * by computing it, but we might not be able to
+ struct r5dev *dev = &sh->dev[disk_idx];
+ struct r5dev *fdev[2] = { &sh->dev[r6s->failed_num[0]],
+ &sh->dev[r6s->failed_num[1]] };
+
+ if (!test_bit(R5_LOCKED, &dev->flags) &&
+ !test_bit(R5_UPTODATE, &dev->flags) &&
+ (dev->toread ||
+ (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) ||
+ s->syncing || s->expanding ||
+ (s->failed >= 1 &&
+ (fdev[0]->toread || s->to_write)) ||
+ (s->failed >= 2 &&
+ (fdev[1]->toread || s->to_write)))) {
+ /* we would like to get this block, possibly by computing it,
+ * otherwise read it if the backing disk is insync
+ */
+ BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
+ BUG_ON(test_bit(R5_Wantread, &dev->flags));
+ if ((s->uptodate == disks - 1) &&
+ (s->failed && (disk_idx == r6s->failed_num[0] ||
+ disk_idx == r6s->failed_num[1]))) {
+ /* have disk failed, and we're requested to fetch it;
+ * do compute it
*/
- if ((s->uptodate == disks - 1) &&
- (s->failed && (i == r6s->failed_num[0] ||
- i == r6s->failed_num[1]))) {
- pr_debug("Computing stripe %llu block %d\n",
- (unsigned long long)sh->sector, i);
- compute_block_1(sh, i, 0);
- s->uptodate++;
- } else if ( s->uptodate == disks-2 && s->failed >= 2 ) {
- /* Computing 2-failure is *very* expensive; only
- * do it if failed >= 2
- */
- int other;
- for (other = disks; other--; ) {
- if (other == i)
- continue;
- if (!test_bit(R5_UPTODATE,
- &sh->dev[other].flags))
- break;
- }
- BUG_ON(other < 0);
- pr_debug("Computing stripe %llu blocks %d,%d\n",
- (unsigned long long)sh->sector,
- i, other);
- compute_block_2(sh, i, other);
- s->uptodate += 2;
- } else if (test_bit(R5_Insync, &dev->flags)) {
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantread, &dev->flags);
- s->locked++;
- pr_debug("Reading block %d (sync=%d)\n",
- i, s->syncing);
+ pr_debug("Computing stripe %llu block %d\n",
+ (unsigned long long)sh->sector, disk_idx);
+ set_bit(STRIPE_COMPUTE_RUN, &sh->state);
+ set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
+ set_bit(R5_Wantcompute, &dev->flags);
+ sh->ops.target = disk_idx;
+ sh->ops.target2 = -1; /* no 2nd target */
+ s->req_compute = 1;
+ s->uptodate++;
+ return 1;
+ } else if (s->uptodate == disks-2 && s->failed >= 2) {
+ /* Computing 2-failure is *very* expensive; only
+ * do it if failed >= 2
+ */
+ int other;
+ for (other = disks; other--; ) {
+ if (other == disk_idx)
+ continue;
+ if (!test_bit(R5_UPTODATE,
+ &sh->dev[other].flags))
+ break;
}
+ BUG_ON(other < 0);
+ pr_debug("Computing stripe %llu blocks %d,%d\n",
+ (unsigned long long)sh->sector,
+ disk_idx, other);
+ set_bit(STRIPE_COMPUTE_RUN, &sh->state);
+ set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
+ set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
+ set_bit(R5_Wantcompute, &sh->dev[other].flags);
+ sh->ops.target = disk_idx;
+ sh->ops.target2 = other;
+ s->uptodate += 2;
+ s->req_compute = 1;
+ return 1;
+ } else if (test_bit(R5_Insync, &dev->flags)) {
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantread, &dev->flags);
+ s->locked++;
+ pr_debug("Reading block %d (sync=%d)\n",
+ disk_idx, s->syncing);
}
}
+
+ return 0;
+}
+
+/**
+ * handle_stripe_fill6 - read or compute data to satisfy pending requests.
+ */
+static void handle_stripe_fill6(struct stripe_head *sh,
+ struct stripe_head_state *s, struct r6_state *r6s,
+ int disks)
+{
+ int i;
+
+ /* look for blocks to read/compute, skip this if a compute
+ * is already in flight, or if the stripe contents are in the
+ * midst of changing due to a write
+ */
+ if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
+ !sh->reconstruct_state)
+ for (i = disks; i--; )
+ if (fetch_block6(sh, s, r6s, i, disks))
+ break;
set_bit(STRIPE_HANDLE, &sh->state);
}
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 4/8] md/raid6: asynchronous handle_stripe_fill6
2009-06-04 1:29 ` [PATCH 4/8] md/raid6: asynchronous handle_stripe_fill6 Dan Williams
@ 2009-06-04 6:37 ` Neil Brown
0 siblings, 0 replies; 11+ messages in thread
From: Neil Brown @ 2009-06-04 6:37 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
On Wednesday June 3, dan.j.williams@intel.com wrote:
> From: Yuri Tikhonov <yur@emcraft.com>
>
> Modify handle_stripe_fill6 to work asynchronously by introducing
> fetch_block6 as the raid6 analog of fetch_block5 (schedule compute
> operations for missing/out-of-sync disks).
Following the theme from the previous patch, fetch_block5 is now just
a special case of fetch_block6, so I think it would be best to use the
same code.
Once you do that, handle_stripe_fill6 and handle_stripe_fill5 become
identical, so you only need handle_stripe_fill.
NeilBrown
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 5/8] md/raid6: asynchronous handle_stripe_dirtying6
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
` (3 preceding siblings ...)
2009-06-04 1:29 ` [PATCH 4/8] md/raid6: asynchronous handle_stripe_fill6 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 1:29 ` [PATCH 6/8] md/raid6: asynchronous handle_parity_check6 Dan Williams
` (2 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
From: Yuri Tikhonov <yur@emcraft.com>
In the synchronous implementation of stripe dirtying we processed a
degraded stripe with one call to handle_stripe_dirtying6(). I.e.
compute the missing blocks from the other drives, then copy in the new
data and reconstruct the parities.
In the asynchronous case we do not perform stripe operations directly.
Instead, operations are scheduled with flags to be later serviced by
raid_run_ops. So, for the degraded case the final reconstruction step
can only be carried out after all blocks have been brought up to date by
being read, or computed. Like the raid5 case schedule_reconstruction()
sets STRIPE_OP_RECONSTRUCT to request a parity generation pass and
through operation chaining can handle compute and reconstruct in a
single raid_run_ops pass.
[dan.j.williams@intel.com: fixup handle_stripe_dirtying6 gating]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 122 ++++++++++++++++------------------------------------
1 files changed, 37 insertions(+), 85 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 836aede..fbc3006 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2759,99 +2759,46 @@ static void handle_stripe_dirtying6(raid5_conf_t *conf,
struct stripe_head *sh, struct stripe_head_state *s,
struct r6_state *r6s, int disks)
{
- int rcw = 0, must_compute = 0, pd_idx = sh->pd_idx, i;
+ int rcw = 0, pd_idx = sh->pd_idx, i;
int qd_idx = sh->qd_idx;
+
+ set_bit(STRIPE_HANDLE, &sh->state);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
- /* Would I have to read this buffer for reconstruct_write */
- if (!test_bit(R5_OVERWRITE, &dev->flags)
- && i != pd_idx && i != qd_idx
- && (!test_bit(R5_LOCKED, &dev->flags)
- ) &&
- !test_bit(R5_UPTODATE, &dev->flags)) {
- if (test_bit(R5_Insync, &dev->flags)) rcw++;
- else {
- pr_debug("raid6: must_compute: "
- "disk %d flags=%#lx\n", i, dev->flags);
- must_compute++;
+ /* check if we haven't enough data */
+ if (!test_bit(R5_OVERWRITE, &dev->flags) &&
+ i != pd_idx && i != qd_idx &&
+ !test_bit(R5_LOCKED, &dev->flags) &&
+ !(test_bit(R5_UPTODATE, &dev->flags) ||
+ test_bit(R5_Wantcompute, &dev->flags))) {
+ rcw++;
+ if (!test_bit(R5_Insync, &dev->flags))
+ continue; /* it's a failed drive */
+
+ if (
+ test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
+ pr_debug("Read_old stripe %llu "
+ "block %d for Reconstruct\n",
+ (unsigned long long)sh->sector, i);
+ set_bit(R5_LOCKED, &dev->flags);
+ set_bit(R5_Wantread, &dev->flags);
+ s->locked++;
+ } else {
+ pr_debug("Request delayed stripe %llu "
+ "block %d for Reconstruct\n",
+ (unsigned long long)sh->sector, i);
+ set_bit(STRIPE_DELAYED, &sh->state);
+ set_bit(STRIPE_HANDLE, &sh->state);
}
}
}
- pr_debug("for sector %llu, rcw=%d, must_compute=%d\n",
- (unsigned long long)sh->sector, rcw, must_compute);
- set_bit(STRIPE_HANDLE, &sh->state);
-
- if (rcw > 0)
- /* want reconstruct write, but need to get some data */
- for (i = disks; i--; ) {
- struct r5dev *dev = &sh->dev[i];
- if (!test_bit(R5_OVERWRITE, &dev->flags)
- && !(s->failed == 0 && (i == pd_idx || i == qd_idx))
- && !test_bit(R5_LOCKED, &dev->flags) &&
- !test_bit(R5_UPTODATE, &dev->flags) &&
- test_bit(R5_Insync, &dev->flags)) {
- if (
- test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
- pr_debug("Read_old stripe %llu "
- "block %d for Reconstruct\n",
- (unsigned long long)sh->sector, i);
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantread, &dev->flags);
- s->locked++;
- } else {
- pr_debug("Request delayed stripe %llu "
- "block %d for Reconstruct\n",
- (unsigned long long)sh->sector, i);
- set_bit(STRIPE_DELAYED, &sh->state);
- set_bit(STRIPE_HANDLE, &sh->state);
- }
- }
- }
/* now if nothing is locked, and if we have enough data, we can start a
* write request
*/
- if (s->locked == 0 && rcw == 0 &&
+ if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
+ s->locked == 0 && rcw == 0 &&
!test_bit(STRIPE_BIT_DELAY, &sh->state)) {
- if (must_compute > 0) {
- /* We have failed blocks and need to compute them */
- switch (s->failed) {
- case 0:
- BUG();
- case 1:
- compute_block_1(sh, r6s->failed_num[0], 0);
- break;
- case 2:
- compute_block_2(sh, r6s->failed_num[0],
- r6s->failed_num[1]);
- break;
- default: /* This request should have been failed? */
- BUG();
- }
- }
-
- pr_debug("Computing parity for stripe %llu\n",
- (unsigned long long)sh->sector);
- compute_parity6(sh, RECONSTRUCT_WRITE);
- /* now every locked buffer is ready to be written */
- for (i = disks; i--; )
- if (test_bit(R5_LOCKED, &sh->dev[i].flags)) {
- pr_debug("Writing stripe %llu block %d\n",
- (unsigned long long)sh->sector, i);
- s->locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
- }
- if (s->locked == disks)
- if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
- atomic_inc(&conf->pending_full_writes);
- /* after a RECONSTRUCT_WRITE, the stripe MUST be in-sync */
- set_bit(STRIPE_INSYNC, &sh->state);
-
- if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
- atomic_dec(&conf->preread_active_stripes);
- if (atomic_read(&conf->preread_active_stripes) <
- IO_THRESHOLD)
- md_wakeup_thread(conf->mddev->thread);
- }
+ schedule_reconstruction(sh, s, 1, 0);
}
}
@@ -3534,8 +3481,13 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
(s.syncing && (s.uptodate < disks)) || s.expanding)
handle_stripe_fill6(sh, &s, &r6s, disks);
- /* now to consider writing and what else, if anything should be read */
- if (s.to_write)
+ /* Now to consider new write requests and what else, if anything
+ * should be read. We do not handle new writes when:
+ * 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
+ * 2/ A 'check' operation is in flight, as it may clobber the parity
+ * block.
+ */
+ if (s.to_write && !sh->reconstruct_state && !sh->check_state)
handle_stripe_dirtying6(conf, sh, &s, &r6s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 6/8] md/raid6: asynchronous handle_parity_check6
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
` (4 preceding siblings ...)
2009-06-04 1:29 ` [PATCH 5/8] md/raid6: asynchronous handle_stripe_dirtying6 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 1:29 ` [PATCH 7/8] md/raid6: asynchronous handle_stripe6 Dan Williams
2009-06-04 1:29 ` [PATCH 8/8] md/raid6: remove synchronous infrastructure Dan Williams
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
[ Based on an original patch by Yuri Tikhonov ]
Implement the state machine for handling the RAID-6 parities check and
repair functionality. Note that the raid6 case does not need to check
for new failures, like raid5, as it will always writeback the correct
disks. The raid5 case can be updated to check zero_sum_result to avoid
getting confused by new failures rather than retrying the entire check
operation.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 138 +++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 103 insertions(+), 35 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index fbc3006..1252ab5 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2895,63 +2895,71 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
struct r6_state *r6s, struct page *tmp_page,
int disks)
{
- int update_p = 0, update_q = 0;
- struct r5dev *dev;
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
+ struct r5dev *dev;
set_bit(STRIPE_HANDLE, &sh->state);
BUG_ON(s->failed > 2);
- BUG_ON(s->uptodate < disks);
+
/* Want to check and possibly repair P and Q.
* However there could be one 'failed' device, in which
* case we can only check one of them, possibly using the
* other to generate missing data
*/
- /* If !tmp_page, we cannot do the calculations,
- * but as we have set STRIPE_HANDLE, we will soon be called
- * by stripe_handle with a tmp_page - just wait until then.
- */
- if (tmp_page) {
+ switch (sh->check_state) {
+ case check_state_idle:
+ /* start a new check operation if there are < 2 failures */
if (s->failed == r6s->q_failed) {
- /* The only possible failed device holds 'Q', so it
+ /* The only possible failed device holds Q, so it
* makes sense to check P (If anything else were failed,
* we would have used P to recreate it).
*/
- compute_block_1(sh, pd_idx, 1);
- if (!page_is_zero(sh->dev[pd_idx].page)) {
- compute_block_1(sh, pd_idx, 0);
- update_p = 1;
- }
+ sh->check_state = check_state_run;
}
if (!r6s->q_failed && s->failed < 2) {
- /* q is not failed, and we didn't use it to generate
+ /* Q is not failed, and we didn't use it to generate
* anything, so it makes sense to check it
*/
- memcpy(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE);
- compute_parity6(sh, UPDATE_PARITY);
- if (memcmp(page_address(tmp_page),
- page_address(sh->dev[qd_idx].page),
- STRIPE_SIZE) != 0) {
- clear_bit(STRIPE_INSYNC, &sh->state);
- update_q = 1;
- }
+ if (sh->check_state == check_state_run)
+ sh->check_state = check_state_run_pq;
+ else
+ sh->check_state = check_state_run_q;
}
- if (update_p || update_q) {
- conf->mddev->resync_mismatches += STRIPE_SECTORS;
- if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
- /* don't try to repair!! */
- update_p = update_q = 0;
+
+ /* discard potentially stale zero_sum_result */
+ sh->ops.zero_sum_result = 0;
+
+ if (sh->check_state == check_state_run) {
+ /* async_xor_zero_sum destroys the contents of P */
+ clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
+ s->uptodate--;
}
+ if (sh->check_state >= check_state_run &&
+ sh->check_state <= check_state_run_pq) {
+ /* async_syndrome_zero_sum preserves P and Q, so
+ * no need to mark them !uptodate here
+ */
+ set_bit(STRIPE_OP_CHECK, &s->ops_request);
+ break;
+ }
+
+ /* we have 2-disk failure */
+ BUG_ON(s->failed != 2);
+ /* fall through */
+ case check_state_compute_result:
+ sh->check_state = check_state_idle;
+
+ /* check that a write has not made the stripe insync */
+ if (test_bit(STRIPE_INSYNC, &sh->state))
+ break;
/* now write out any block on a failed drive,
- * or P or Q if they need it
+ * or P or Q if they were recomputed
*/
-
+ BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */
if (s->failed == 2) {
dev = &sh->dev[r6s->failed_num[1]];
s->locked++;
@@ -2964,14 +2972,13 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
-
- if (update_p) {
+ if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
dev = &sh->dev[pd_idx];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
- if (update_q) {
+ if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
dev = &sh->dev[qd_idx];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
@@ -2980,6 +2987,67 @@ static void handle_parity_checks6(raid5_conf_t *conf, struct stripe_head *sh,
clear_bit(STRIPE_DEGRADED, &sh->state);
set_bit(STRIPE_INSYNC, &sh->state);
+ break;
+ case check_state_run:
+ case check_state_run_q:
+ case check_state_run_pq:
+ break; /* we will be called again upon completion */
+ case check_state_check_result:
+ sh->check_state = check_state_idle;
+
+ /* handle a successful check operation, if parity is correct
+ * we are done. Otherwise update the mismatch count and repair
+ * parity if !MD_RECOVERY_CHECK
+ */
+ if (sh->ops.zero_sum_result == 0) {
+ /* both parities are correct */
+ if (!s->failed)
+ set_bit(STRIPE_INSYNC, &sh->state);
+ else {
+ /* in contrast to the raid5 case we can validate
+ * parity, but still have a failure to write
+ * back
+ */
+ sh->check_state = check_state_compute_result;
+ /* Returning at this point means that we may go
+ * off and bring p and/or q uptodate again so
+ * we make sure to check zero_sum_result again
+ * to verify if p or q need writeback
+ */
+ }
+ } else {
+ conf->mddev->resync_mismatches += STRIPE_SECTORS;
+ if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
+ /* don't try to repair!! */
+ set_bit(STRIPE_INSYNC, &sh->state);
+ else {
+ sh->check_state = check_state_compute_run;
+ set_bit(STRIPE_COMPUTE_RUN, &sh->state);
+ set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
+ if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[pd_idx].flags);
+ sh->ops.target = pd_idx;
+ s->uptodate++;
+ } else
+ sh->ops.target = -1;
+ if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
+ set_bit(R5_Wantcompute,
+ &sh->dev[qd_idx].flags);
+ sh->ops.target2 = qd_idx;
+ s->uptodate++;
+ } else
+ sh->ops.target2 = -1;
+ }
+ }
+ break;
+ case check_state_compute_run:
+ break;
+ default:
+ printk(KERN_ERR "%s: unknown check_state: %d sector: %llu\n",
+ __func__, sh->check_state,
+ (unsigned long long) sh->sector);
+ BUG();
}
}
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 7/8] md/raid6: asynchronous handle_stripe6
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
` (5 preceding siblings ...)
2009-06-04 1:29 ` [PATCH 6/8] md/raid6: asynchronous handle_parity_check6 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
2009-06-04 1:29 ` [PATCH 8/8] md/raid6: remove synchronous infrastructure Dan Williams
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
From: Yuri Tikhonov <yur@emcraft.com>
1/ Use STRIPE_OP_BIOFILL to offload completion of read requests to
raid_run_ops
2/ Implement a handler for sh->reconstruct_state similar to the raid5 case
(adds handling of Q parity)
3/ Prevent handle_parity_checks6 from running concurrently with 'compute'
operations
4/ Hook up raid_run_ops
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 120 ++++++++++++++++++++++++++++++++++++----------------
1 files changed, 82 insertions(+), 38 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 1252ab5..09dd4ab 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3415,9 +3415,10 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
mdk_rdev_t *blocked_rdev = NULL;
pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
- "pd_idx=%d, qd_idx=%d\n",
+ "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
(unsigned long long)sh->sector, sh->state,
- atomic_read(&sh->count), pd_idx, qd_idx);
+ atomic_read(&sh->count), pd_idx, qd_idx,
+ sh->check_state, sh->reconstruct_state);
memset(&s, 0, sizeof(s));
spin_lock(&sh->lock);
@@ -3437,35 +3438,24 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
i, dev->flags, dev->toread, dev->towrite, dev->written);
- /* maybe we can reply to a read */
- if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread) {
- struct bio *rbi, *rbi2;
- pr_debug("Return read for disc %d\n", i);
- spin_lock_irq(&conf->device_lock);
- rbi = dev->toread;
- dev->toread = NULL;
- if (test_and_clear_bit(R5_Overlap, &dev->flags))
- wake_up(&conf->wait_for_overlap);
- spin_unlock_irq(&conf->device_lock);
- while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) {
- copy_data(0, rbi, dev->page, dev->sector);
- rbi2 = r5_next_bio(rbi, dev->sector);
- spin_lock_irq(&conf->device_lock);
- if (!raid5_dec_bi_phys_segments(rbi)) {
- rbi->bi_next = return_bi;
- return_bi = rbi;
- }
- spin_unlock_irq(&conf->device_lock);
- rbi = rbi2;
- }
- }
+ /* maybe we can reply to a read
+ *
+ * new wantfill requests are only permitted while
+ * ops_complete_biofill is guaranteed to be inactive
+ */
+ if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
+ !test_bit(STRIPE_BIOFILL_RUN, &sh->state))
+ set_bit(R5_Wantfill, &dev->flags);
/* now count some things */
if (test_bit(R5_LOCKED, &dev->flags)) s.locked++;
if (test_bit(R5_UPTODATE, &dev->flags)) s.uptodate++;
+ if (test_bit(R5_Wantcompute, &dev->flags))
+ BUG_ON(++s.compute > 2);
-
- if (dev->toread)
+ if (test_bit(R5_Wantfill, &dev->flags)) {
+ s.to_fill++;
+ } else if (dev->toread)
s.to_read++;
if (dev->towrite) {
s.to_write++;
@@ -3506,6 +3496,11 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
blocked_rdev = NULL;
}
+ if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
+ set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
+ set_bit(STRIPE_BIOFILL_RUN, &sh->state);
+ }
+
pr_debug("locked=%d uptodate=%d to_read=%d"
" to_write=%d failed=%d failed_num=%d,%d\n",
s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
@@ -3546,9 +3541,43 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
* or to load a block that is being partially written.
*/
if (s.to_read || s.non_overwrite || (s.to_write && s.failed) ||
- (s.syncing && (s.uptodate < disks)) || s.expanding)
+ (s.syncing && (s.uptodate + s.compute < disks)) || s.expanding)
handle_stripe_fill6(sh, &s, &r6s, disks);
+ /* Now we check to see if any write operations have recently
+ * completed
+ */
+ if (sh->reconstruct_state == reconstruct_state_drain_result) {
+ int qd_idx = sh->qd_idx;
+
+ sh->reconstruct_state = reconstruct_state_idle;
+ /* All the 'written' buffers and the parity blocks are ready to
+ * be written back to disk
+ */
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags));
+ BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags));
+ for (i = disks; i--; ) {
+ dev = &sh->dev[i];
+ if (test_bit(R5_LOCKED, &dev->flags) &&
+ (i == sh->pd_idx || i == qd_idx ||
+ dev->written)) {
+ pr_debug("Writing block %d\n", i);
+ BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
+ set_bit(R5_Wantwrite, &dev->flags);
+ if (!test_bit(R5_Insync, &dev->flags) ||
+ ((i == sh->pd_idx || i == qd_idx) &&
+ s.failed == 0))
+ set_bit(STRIPE_INSYNC, &sh->state);
+ }
+ }
+ if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
+ atomic_dec(&conf->preread_active_stripes);
+ if (atomic_read(&conf->preread_active_stripes) <
+ IO_THRESHOLD)
+ md_wakeup_thread(conf->mddev->thread);
+ }
+ }
+
/* Now to consider new write requests and what else, if anything
* should be read. We do not handle new writes when:
* 1/ A 'write' operation (copy+gen_syndrome) is already in flight.
@@ -3560,9 +3589,13 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
/* maybe we need to check and possibly fix the parity for this stripe
* Any reads will already have been scheduled, so we just see if enough
- * data is available
+ * data is available. The parity check is held off while parity
+ * dependent operations are in flight.
*/
- if (s.syncing && s.locked == 0 && !test_bit(STRIPE_INSYNC, &sh->state))
+ if (sh->check_state ||
+ (s.syncing && s.locked == 0 &&
+ !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
+ !test_bit(STRIPE_INSYNC, &sh->state)))
handle_parity_checks6(conf, sh, &s, &r6s, tmp_page, disks);
if (s.syncing && s.locked == 0 && test_bit(STRIPE_INSYNC, &sh->state)) {
@@ -3584,15 +3617,29 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
set_bit(R5_Wantwrite, &dev->flags);
set_bit(R5_ReWrite, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
+ s.locked++;
} else {
/* let's read it back */
set_bit(R5_Wantread, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
+ s.locked++;
}
}
}
- if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
+ /* Finish reconstruct operations initiated by the expansion process */
+ if (sh->reconstruct_state == reconstruct_state_result) {
+ sh->reconstruct_state = reconstruct_state_idle;
+ clear_bit(STRIPE_EXPANDING, &sh->state);
+ for (i = conf->raid_disks; i--; ) {
+ set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ set_bit(R5_LOCKED, &sh->dev[i].flags);
+ s.locked++;
+ }
+ }
+
+ if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
+ !sh->reconstruct_state) {
struct stripe_head *sh2
= get_active_stripe(conf, sh->sector, 1, 1);
if (sh2 && test_bit(STRIPE_EXPAND_SOURCE, &sh2->state)) {
@@ -3613,14 +3660,8 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
/* Need to write out all blocks after computing P&Q */
sh->disks = conf->raid_disks;
stripe_set_idx(sh->sector, conf, 0, sh);
- compute_parity6(sh, RECONSTRUCT_WRITE);
- for (i = conf->raid_disks ; i-- ; ) {
- set_bit(R5_LOCKED, &sh->dev[i].flags);
- s.locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
- }
- clear_bit(STRIPE_EXPANDING, &sh->state);
- } else if (s.expanded) {
+ schedule_reconstruction(sh, &s, 1, 1);
+ } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
wake_up(&conf->wait_for_overlap);
@@ -3638,6 +3679,9 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
if (unlikely(blocked_rdev))
md_wait_for_blocked_rdev(blocked_rdev, conf->mddev);
+ if (s.ops_request)
+ raid_run_ops(sh, s.ops_request);
+
ops_run_io(sh, &s);
return_io(return_bi);
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 8/8] md/raid6: remove synchronous infrastructure
2009-06-04 1:28 [PATCH 0/8] Asynchronous raid6 acceleration (part 3 of 3) Dan Williams
` (6 preceding siblings ...)
2009-06-04 1:29 ` [PATCH 7/8] md/raid6: asynchronous handle_stripe6 Dan Williams
@ 2009-06-04 1:29 ` Dan Williams
7 siblings, 0 replies; 11+ messages in thread
From: Dan Williams @ 2009-06-04 1:29 UTC (permalink / raw)
To: neilb; +Cc: linux-raid, Ilya Yanok, Yuri Tikhonov
From: Yuri Tikhonov <yur@emcraft.com>
These routines have been replaced by there asynchronous counterparts.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/md/raid5.c | 254 ----------------------------------------------------
1 files changed, 0 insertions(+), 254 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 09dd4ab..dbcc1f1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1920,253 +1920,6 @@ 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)
@@ -2324,13 +2077,6 @@ 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)
{
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