From c8ac1803ff0af5aa614587ac0c66d46b7a3bdfcc Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 27 Jul 2011 11:00:36 +1000 Subject: [PATCH] md/raid5: unite handle_stripe_dirtying5 and handle_stripe_dirtying6 RAID6 is only allowed to choose 'reconstruct-write' while RAID5 is also allow 'read-modify-write' Apart from this difference, handle_stripe_dirtying[56] are nearly identical. So resolve these differences and create just one function. Signed-off-by: NeilBrown Reviewed-by: Namhyung Kim --- drivers/md/raid5.c | 77 +++++++++++++--------------------------------- 1 file changed, 21 insertions(+), 56 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index a63a679105ca..a3018970d6a3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2468,11 +2468,19 @@ static void handle_stripe_clean_event(raid5_conf_t *conf, md_wakeup_thread(conf->mddev->thread); } -static void handle_stripe_dirtying5(raid5_conf_t *conf, - struct stripe_head *sh, struct stripe_head_state *s, int disks) +static void handle_stripe_dirtying(raid5_conf_t *conf, + struct stripe_head *sh, + struct stripe_head_state *s, + int disks) { int rmw = 0, rcw = 0, i; - for (i = disks; i--; ) { + if (conf->max_degraded == 2) { + /* RAID6 requires 'rcw' in current implementation + * Calculate the real rcw later - for now fake it + * look like rcw is cheaper + */ + rcw = 1; rmw = 2; + } else for (i = disks; i--; ) { /* would I have to read this buffer for read_modify_write */ struct r5dev *dev = &sh->dev[i]; if ((dev->towrite || i == sh->pd_idx) && @@ -2519,16 +2527,19 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf, } } } - if (rcw <= rmw && rcw > 0) + if (rcw <= rmw && rcw > 0) { /* want reconstruct write, but need to get some data */ + rcw = 0; for (i = disks; i--; ) { struct r5dev *dev = &sh->dev[i]; if (!test_bit(R5_OVERWRITE, &dev->flags) && - i != sh->pd_idx && + i != sh->pd_idx && i != sh->qd_idx && !test_bit(R5_LOCKED, &dev->flags) && !(test_bit(R5_UPTODATE, &dev->flags) || - test_bit(R5_Wantcompute, &dev->flags)) && - test_bit(R5_Insync, &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 block " @@ -2542,6 +2553,7 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf, } } } + } /* now if nothing is locked, and if we have enough data, * we can start a write request */ @@ -2558,53 +2570,6 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf, schedule_reconstruction(sh, s, rcw == 0, 0); } -static void handle_stripe_dirtying6(raid5_conf_t *conf, - struct stripe_head *sh, struct stripe_head_state *s, - int disks) -{ - 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]; - /* 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); - } - } - } - /* now if nothing is locked, and if we have enough data, we can start a - * write request - */ - if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) && - s->locked == 0 && rcw == 0 && - !test_bit(STRIPE_BIT_DELAY, &sh->state)) { - schedule_reconstruction(sh, s, 1, 0); - } -} - static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh, struct stripe_head_state *s, int disks) { @@ -3099,7 +3064,7 @@ static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s) * block. */ if (s->to_write && !sh->reconstruct_state && !sh->check_state) - handle_stripe_dirtying5(conf, sh, s, disks); + handle_stripe_dirtying(conf, sh, s, disks); /* 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 @@ -3288,7 +3253,7 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s) * block. */ if (s->to_write && !sh->reconstruct_state && !sh->check_state) - handle_stripe_dirtying6(conf, sh, s, disks); + handle_stripe_dirtying(conf, sh, s, disks); /* 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 -- 2.20.1