From 600aa10993012ff2dd5617720dac081e4f992017 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 28 Jun 2008 08:32:05 +1000 Subject: [PATCH] md: replace STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} with 'reconstruct_states' From: Dan Williams Track the state of reconstruct operations (recalculating the parity block usually due to incoming writes, or as part of array expansion) Reduces the scope of the STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} flags to only tracking whether a reconstruct operation has been requested via the ops_request field of struct stripe_head_state. This is the final step in the removal of ops.{pending,ack,complete,count}, i.e. the STRIPE_OP_{BIODRAIN,PREXOR,POSTXOR} flags only request an operation and do not track the state of the operation. Signed-off-by: Dan Williams Signed-off-by: Neil Brown --- drivers/md/raid5.c | 204 +++++++++++-------------------------- include/linux/raid/raid5.h | 9 +- 2 files changed, 63 insertions(+), 150 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 835046bf38..b915936749 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -122,6 +122,13 @@ static void return_io(struct bio *return_bi) static void print_raid5_conf (raid5_conf_t *conf); +static int stripe_operations_active(struct stripe_head *sh) +{ + return sh->check_state || sh->reconstruct_state || + test_bit(STRIPE_BIOFILL_RUN, &sh->state) || + test_bit(STRIPE_COMPUTE_RUN, &sh->state); +} + static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) { if (atomic_dec_and_test(&sh->count)) { @@ -141,7 +148,7 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) } md_wakeup_thread(conf->mddev->thread); } else { - BUG_ON(sh->ops.pending); + BUG_ON(stripe_operations_active(sh)); 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) @@ -243,7 +250,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int BUG_ON(atomic_read(&sh->count) != 0); BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); - BUG_ON(sh->ops.pending || sh->ops.ack || sh->ops.complete); + BUG_ON(stripe_operations_active(sh)); CHECK_DEVLOCK(); pr_debug("init_stripe called, stripe %llu\n", @@ -344,47 +351,6 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector return sh; } -/* test_and_ack_op() ensures that we only dequeue an operation once */ -#define test_and_ack_op(op, pend) \ -do { \ - if (test_bit(op, &sh->ops.pending) && \ - !test_bit(op, &sh->ops.complete)) { \ - if (test_and_set_bit(op, &sh->ops.ack)) \ - clear_bit(op, &pend); \ - else \ - ack++; \ - } else \ - clear_bit(op, &pend); \ -} while (0) - -/* find new work to run, do not resubmit work that is already - * in flight - */ -static unsigned long get_stripe_work(struct stripe_head *sh) -{ - unsigned long pending; - int ack = 0; - - pending = sh->ops.pending; - - test_and_ack_op(STRIPE_OP_BIOFILL, pending); - test_and_ack_op(STRIPE_OP_COMPUTE_BLK, pending); - test_and_ack_op(STRIPE_OP_PREXOR, pending); - test_and_ack_op(STRIPE_OP_BIODRAIN, pending); - test_and_ack_op(STRIPE_OP_POSTXOR, pending); - test_and_ack_op(STRIPE_OP_CHECK, pending); - - sh->ops.count -= ack; - if (unlikely(sh->ops.count < 0)) { - printk(KERN_ERR "pending: %#lx ops.pending: %#lx ops.ack: %#lx " - "ops.complete: %#lx\n", pending, sh->ops.pending, - sh->ops.ack, sh->ops.complete); - BUG(); - } - - return pending; -} - static void raid5_end_read_request(struct bio *bi, int error); static void @@ -609,7 +575,7 @@ static void ops_complete_compute5(void *stripe_head_ref) } static struct dma_async_tx_descriptor * -ops_run_compute5(struct stripe_head *sh, unsigned long pending) +ops_run_compute5(struct stripe_head *sh, unsigned long ops_request) { /* kernel stack size limits the total number of disks */ int disks = sh->disks; @@ -640,7 +606,7 @@ ops_run_compute5(struct stripe_head *sh, unsigned long pending) ops_complete_compute5, sh); /* ack now if postxor is not set to be run */ - if (tx && !test_bit(STRIPE_OP_POSTXOR, &pending)) + if (tx && !test_bit(STRIPE_OP_POSTXOR, &ops_request)) async_tx_ack(tx); return tx; @@ -652,8 +618,6 @@ static void ops_complete_prexor(void *stripe_head_ref) pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); - - set_bit(STRIPE_OP_PREXOR, &sh->ops.complete); } static struct dma_async_tx_descriptor * @@ -686,7 +650,7 @@ ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) static struct dma_async_tx_descriptor * ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx, - unsigned long pending) + unsigned long ops_request) { int disks = sh->disks; int pd_idx = sh->pd_idx, i; @@ -694,7 +658,7 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx, /* check if prexor is active which means only process blocks * that are part of a read-modify-write (Wantprexor) */ - int prexor = test_bit(STRIPE_OP_PREXOR, &pending); + int prexor = test_bit(STRIPE_OP_PREXOR, &ops_request); pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); @@ -744,7 +708,7 @@ static void ops_complete_postxor(void *stripe_head_ref) pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector); - set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete); + sh->reconstruct_state = reconstruct_state_result; set_bit(STRIPE_HANDLE, &sh->state); release_stripe(sh); } @@ -763,16 +727,14 @@ static void ops_complete_write(void *stripe_head_ref) set_bit(R5_UPTODATE, &dev->flags); } - set_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete); - set_bit(STRIPE_OP_POSTXOR, &sh->ops.complete); - + sh->reconstruct_state = reconstruct_state_drain_result; set_bit(STRIPE_HANDLE, &sh->state); release_stripe(sh); } static void ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx, - unsigned long pending) + unsigned long ops_request) { /* kernel stack size limits the total number of disks */ int disks = sh->disks; @@ -780,7 +742,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx, int count = 0, pd_idx = sh->pd_idx, i; struct page *xor_dest; - int prexor = test_bit(STRIPE_OP_PREXOR, &pending); + int prexor = test_bit(STRIPE_OP_PREXOR, &ops_request); unsigned long flags; dma_async_tx_callback callback; @@ -807,7 +769,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx, } /* check whether this postxor is part of a write */ - callback = test_bit(STRIPE_OP_BIODRAIN, &pending) ? + callback = test_bit(STRIPE_OP_BIODRAIN, &ops_request) ? ops_complete_write : ops_complete_postxor; /* 1/ if we prexor'd then the dest is reused as a source @@ -868,8 +830,7 @@ static void ops_run_check(struct stripe_head *sh) ops_complete_check, sh); } -static void raid5_run_ops(struct stripe_head *sh, unsigned long pending, - unsigned long ops_request) +static void raid5_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; @@ -880,18 +841,18 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long pending, } if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) - tx = ops_run_compute5(sh, pending); + tx = ops_run_compute5(sh, ops_request); - if (test_bit(STRIPE_OP_PREXOR, &pending)) + if (test_bit(STRIPE_OP_PREXOR, &ops_request)) tx = ops_run_prexor(sh, tx); - if (test_bit(STRIPE_OP_BIODRAIN, &pending)) { - tx = ops_run_biodrain(sh, tx, pending); + if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) { + tx = ops_run_biodrain(sh, tx, ops_request); overlap_clear++; } - if (test_bit(STRIPE_OP_POSTXOR, &pending)) - ops_run_postxor(sh, tx, pending); + if (test_bit(STRIPE_OP_POSTXOR, &ops_request)) + ops_run_postxor(sh, tx, ops_request); if (test_bit(STRIPE_OP_CHECK, &ops_request)) ops_run_check(sh); @@ -1684,11 +1645,11 @@ static void compute_block_2(struct stripe_head *sh, int dd_idx1, int dd_idx2) } } -static int -handle_write_operations5(struct stripe_head *sh, int rcw, int expand) +static void +handle_write_operations5(struct stripe_head *sh, struct stripe_head_state *s, + int rcw, int expand) { int i, pd_idx = sh->pd_idx, disks = sh->disks; - int locked = 0; if (rcw) { /* if we are not expanding this is a proper write request, and @@ -1696,12 +1657,12 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand) * stripe cache */ if (!expand) { - set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending); - sh->ops.count++; - } + sh->reconstruct_state = reconstruct_state_drain_run; + set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); + } else + sh->reconstruct_state = reconstruct_state_run; - set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending); - sh->ops.count++; + set_bit(STRIPE_OP_POSTXOR, &s->ops_request); for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; @@ -1710,21 +1671,20 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand) set_bit(R5_LOCKED, &dev->flags); if (!expand) clear_bit(R5_UPTODATE, &dev->flags); - locked++; + s->locked++; } } - if (locked + 1 == disks) + if (s->locked + 1 == disks) if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state)) atomic_inc(&sh->raid_conf->pending_full_writes); } else { BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) || test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags))); - set_bit(STRIPE_OP_PREXOR, &sh->ops.pending); - set_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending); - set_bit(STRIPE_OP_POSTXOR, &sh->ops.pending); - - sh->ops.count += 3; + sh->reconstruct_state = reconstruct_state_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); for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; @@ -1742,7 +1702,7 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand) set_bit(R5_Wantprexor, &dev->flags); set_bit(R5_LOCKED, &dev->flags); clear_bit(R5_UPTODATE, &dev->flags); - locked++; + s->locked++; } } } @@ -1752,13 +1712,11 @@ handle_write_operations5(struct stripe_head *sh, int rcw, int expand) */ set_bit(R5_LOCKED, &sh->dev[pd_idx].flags); clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags); - locked++; + s->locked++; - pr_debug("%s: stripe %llu locked: %d pending: %lx\n", + pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n", __func__, (unsigned long long)sh->sector, - locked, sh->ops.pending); - - return locked; + s->locked, s->ops_request); } /* @@ -2005,8 +1963,7 @@ static void handle_issuing_new_read_requests5(struct stripe_head *sh, * midst of changing due to a write */ if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state && - !test_bit(STRIPE_OP_PREXOR, &sh->ops.pending) && - !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) { + !sh->reconstruct_state) { for (i = disks; i--; ) if (__handle_issuing_new_read_requests5( sh, s, i, disks) == 0) @@ -2211,7 +2168,7 @@ static void handle_issuing_new_write_requests5(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))) - s->locked += handle_write_operations5(sh, rcw == 0, 0); + handle_write_operations5(sh, s, rcw == 0, 0); } static void handle_issuing_new_write_requests6(raid5_conf_t *conf, @@ -2581,15 +2538,14 @@ static void handle_stripe5(struct stripe_head *sh) struct bio *return_bi = NULL; struct stripe_head_state s; struct r5dev *dev; - unsigned long pending = 0; mdk_rdev_t *blocked_rdev = NULL; int prexor; memset(&s, 0, sizeof(s)); - pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d " - "ops=%lx:%lx:%lx\n", (unsigned long long)sh->sector, sh->state, - atomic_read(&sh->count), sh->pd_idx, - sh->ops.pending, sh->ops.ack, sh->ops.complete); + pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d " + "reconstruct:%d\n", (unsigned long long)sh->sector, sh->state, + atomic_read(&sh->count), sh->pd_idx, sh->check_state, + sh->reconstruct_state); spin_lock(&sh->lock); clear_bit(STRIPE_HANDLE, &sh->state); @@ -2703,34 +2659,12 @@ static void handle_stripe5(struct stripe_head *sh) /* Now we check to see if any write operations have recently * completed */ - - /* leave prexor set until postxor is done, allows us to distinguish - * a rmw from a rcw during biodrain - */ prexor = 0; - if (test_bit(STRIPE_OP_PREXOR, &sh->ops.complete) && - test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) { - - prexor = 1; - clear_bit(STRIPE_OP_PREXOR, &sh->ops.complete); - clear_bit(STRIPE_OP_PREXOR, &sh->ops.ack); - clear_bit(STRIPE_OP_PREXOR, &sh->ops.pending); - + if (sh->reconstruct_state == reconstruct_state_drain_result) { + sh->reconstruct_state = reconstruct_state_idle; for (i = disks; i--; ) - clear_bit(R5_Wantprexor, &sh->dev[i].flags); - } - - /* if only POSTXOR is set then this is an 'expand' postxor */ - if (test_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete) && - test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) { - - clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.complete); - clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.ack); - clear_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending); - - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete); - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack); - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending); + prexor += test_and_clear_bit(R5_Wantprexor, + &sh->dev[i].flags); /* All the 'written' buffers and the parity block are ready to * be written back to disk @@ -2763,8 +2697,7 @@ static void handle_stripe5(struct stripe_head *sh) * 2/ A 'check' operation is in flight, as it may clobber the parity * block. */ - if (s.to_write && !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending) && - !sh->check_state) + if (s.to_write && !sh->reconstruct_state && !sh->check_state) handle_issuing_new_write_requests5(conf, sh, &s, disks); /* maybe we need to check and possibly fix the parity for this stripe @@ -2805,18 +2738,10 @@ static void handle_stripe5(struct stripe_head *sh) } } - /* Finish postxor operations initiated by the expansion - * process - */ - if (test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete) && - !test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending)) { - + /* 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); - - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending); - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack); - clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete); - for (i = conf->raid_disks; i--; ) set_bit(R5_Wantwrite, &sh->dev[i].flags); set_bit(R5_LOCKED, &dev->flags); @@ -2824,15 +2749,13 @@ static void handle_stripe5(struct stripe_head *sh) } if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && - !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) { + !sh->reconstruct_state) { /* Need to write out all blocks after computing parity */ sh->disks = conf->raid_disks; sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); - s.locked += handle_write_operations5(sh, 1, 1); - } else if (s.expanded && - s.locked == 0 && - !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) { + handle_write_operations5(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); @@ -2843,9 +2766,6 @@ static void handle_stripe5(struct stripe_head *sh) !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) handle_stripe_expansion(conf, sh, NULL); - if (sh->ops.count) - pending = get_stripe_work(sh); - unlock: spin_unlock(&sh->lock); @@ -2853,8 +2773,8 @@ static void handle_stripe5(struct stripe_head *sh) if (unlikely(blocked_rdev)) md_wait_for_blocked_rdev(blocked_rdev, conf->mddev); - if (pending || s.ops_request) - raid5_run_ops(sh, pending, s.ops_request); + if (s.ops_request) + raid5_run_ops(sh, s.ops_request); ops_run_io(sh, &s); diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h index 2c96d5fd54..5f3e674b87 100644 --- a/include/linux/raid/raid5.h +++ b/include/linux/raid/raid5.h @@ -205,19 +205,12 @@ struct stripe_head { int bm_seq; /* sequence number for bitmap flushes */ int disks; /* disks in stripe */ enum check_states check_state; + enum reconstruct_states reconstruct_state; /* stripe_operations - * @pending - pending ops flags (set for request->issue->complete) - * @ack - submitted ops flags (set for issue->complete) - * @complete - completed ops flags (set for complete) * @target - STRIPE_OP_COMPUTE_BLK target - * @count - raid5_runs_ops is set to run when this is non-zero */ struct stripe_operations { - unsigned long pending; - unsigned long ack; - unsigned long complete; int target; - int count; u32 zero_sum_result; } ops; struct r5dev { -- 2.39.5