From ac6b53b6e6acab27e4f3e2383f9ac1f0d7c6200b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 14 Jul 2009 13:40:19 -0700 Subject: md/raid6: asynchronous raid6 operations [ 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 Signed-off-by: Yuri Tikhonov Signed-off-by: Ilya Yanok Signed-off-by: Dan Williams diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 41b3ae2..abb8636 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_RAID6_RECOV ---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 e3a2990..e68616e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -636,15 +636,16 @@ 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) @@ -684,7 +685,7 @@ ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) atomic_inc(&sh->count); init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL, - ops_complete_compute5, sh, to_addr_conv(sh, percpu)); + ops_complete_compute, sh, to_addr_conv(sh, percpu)); if (unlikely(count == 1)) tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); else @@ -693,6 +694,197 @@ ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu) 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, struct raid5_percpu *percpu) +{ + int disks = sh->disks; + struct page **blocks = percpu->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, + to_addr_conv(sh, percpu)); + 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, + to_addr_conv(sh, percpu)); + 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, struct raid5_percpu *percpu) +{ + 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 = percpu->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, to_addr_conv(sh, percpu)); + 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, to_addr_conv(sh, percpu)); + 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, to_addr_conv(sh, percpu)); + return async_gen_syndrome(blocks, 0, count+2, + STRIPE_SIZE, &submit); + } + } + + init_async_submit(&submit, 0, NULL, ops_complete_compute, sh, + to_addr_conv(sh, percpu)); + 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; @@ -765,17 +957,21 @@ 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); } @@ -793,8 +989,8 @@ static void ops_complete_postxor(void *stripe_head_ref) } static void -ops_run_postxor(struct stripe_head *sh, struct raid5_percpu *percpu, - struct dma_async_tx_descriptor *tx) +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; @@ -837,7 +1033,7 @@ ops_run_postxor(struct stripe_head *sh, struct raid5_percpu *percpu, atomic_inc(&sh->count); - init_async_submit(&submit, flags, tx, ops_complete_postxor, sh, + init_async_submit(&submit, flags, tx, ops_complete_reconstruct, sh, to_addr_conv(sh, percpu)); if (unlikely(count == 1)) tx = async_memcpy(xor_dest, xor_srcs[0], 0, 0, STRIPE_SIZE, &submit); @@ -845,6 +1041,25 @@ ops_run_postxor(struct stripe_head *sh, struct raid5_percpu *percpu, tx = async_xor(xor_dest, xor_srcs, 0, count, STRIPE_SIZE, &submit); } +static void +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; + 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, to_addr_conv(sh, percpu)); + 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; @@ -857,23 +1072,28 @@ static void ops_complete_check(void *stripe_head_ref) release_stripe(sh); } -static void ops_run_check(struct stripe_head *sh, struct raid5_percpu *percpu) +static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu) { int disks = sh->disks; + int pd_idx = sh->pd_idx; + int qd_idx = sh->qd_idx; + struct page *xor_dest; struct page **xor_srcs = percpu->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, @@ -886,11 +1106,32 @@ static void ops_run_check(struct stripe_head *sh, struct raid5_percpu *percpu) 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, struct raid5_percpu *percpu, int checkp) +{ + struct page **srcs = percpu->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, to_addr_conv(sh, percpu)); + async_syndrome_val(srcs, 0, count+2, STRIPE_SIZE, + &sh->ops.zero_sum_result, percpu->spare_page, &submit); +} + +static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) { int overlap_clear = 0, i, disks = sh->disks; struct dma_async_tx_descriptor *tx = NULL; raid5_conf_t *conf = sh->raid_conf; + int level = conf->level; struct raid5_percpu *percpu; unsigned long cpu; @@ -902,9 +1143,16 @@ 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, percpu); - /* 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, percpu); + else { + if (sh->ops.target2 < 0 || sh->ops.target < 0) + tx = ops_run_compute6_1(sh, percpu); + else + tx = ops_run_compute6_2(sh, percpu); + } + /* terminate the chain if reconstruct is not set to be run */ + if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) async_tx_ack(tx); } @@ -916,11 +1164,23 @@ 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, percpu, tx); + if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) { + if (level < 6) + ops_run_reconstruct5(sh, percpu, tx); + else + ops_run_reconstruct6(sh, percpu, tx); + } - if (test_bit(STRIPE_OP_CHECK, &ops_request)) - ops_run_check(sh, percpu); + if (test_bit(STRIPE_OP_CHECK, &ops_request)) { + if (sh->check_state == check_state_run) + ops_run_check_p(sh, percpu); + else if (sh->check_state == check_state_run_q) + ops_run_check_pq(sh, percpu, 0); + else if (sh->check_state == check_state_run_pq) + ops_run_check_pq(sh, percpu, 1); + else + BUG(); + } if (overlap_clear) for (i = disks; i--; ) { @@ -1931,7 +2191,7 @@ 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]; @@ -1954,7 +2214,7 @@ 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]; @@ -2206,9 +2466,10 @@ 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. @@ -2435,8 +2696,8 @@ 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. */ @@ -2618,6 +2879,7 @@ 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++; } } @@ -3067,7 +3329,7 @@ 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 75f2c6c..116d0b4 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, @@ -216,7 +218,7 @@ 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 { @@ -299,7 +301,7 @@ 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 /* -- cgit v0.10.2