From b5663ba405fe3e51176ddb6c91a5e186590c26b5 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 14:39:38 +1100 Subject: [PATCH] md/raid5: simplify interface for init_stripe and get_active_stripe Rather than passing 'pd_idx' and 'disks' to these functions, just pass 'previous' which tells whether to use the 'previous' or 'current' geometry during a reshape, and let init_stripe calculate disks and pd_idx and anything else it might need. This is not a substantial simplification and even adds a division. However we will shortly be adding more complexity to init_stripe to handle more interesting 'reshape' activities, and without this change, the interface to these functions would get very complex. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 43 ++++++++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4d7142376e5..c38310be0d9 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -274,8 +274,9 @@ static int grow_buffers(struct stripe_head *sh, int num) } static void raid5_build_block(struct stripe_head *sh, int i); +static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int disks); -static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int disks) +static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) { raid5_conf_t *conf = sh->raid_conf; int i; @@ -290,11 +291,11 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int pd_idx, int remove_hash(sh); + sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; sh->sector = sector; - sh->pd_idx = pd_idx; + sh->pd_idx = stripe_to_pdidx(sector, conf, sh->disks); sh->state = 0; - sh->disks = disks; for (i = sh->disks; i--; ) { struct r5dev *dev = &sh->dev[i]; @@ -330,10 +331,12 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, in static void unplug_slaves(mddev_t *mddev); static void raid5_unplug_device(struct request_queue *q); -static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks, - int pd_idx, int noblock) +static struct stripe_head * +get_active_stripe(raid5_conf_t *conf, sector_t sector, + int previous, int noblock) { struct stripe_head *sh; + int disks = previous ? conf->previous_raid_disks : conf->raid_disks; pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector); @@ -361,7 +364,7 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector ); conf->inactive_blocked = 0; } else - init_stripe(sh, sector, pd_idx, disks); + init_stripe(sh, sector, previous); } else { if (atomic_read(&sh->count)) { BUG_ON(!list_empty(&sh->lru)); @@ -2479,8 +2482,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh, conf->raid_disks - conf->max_degraded, &dd_idx, &pd_idx, conf); - sh2 = get_active_stripe(conf, s, conf->raid_disks, - pd_idx, 1); + sh2 = get_active_stripe(conf, s, 0, 1); if (sh2 == NULL) /* so far only the early blocks of this stripe * have been requested. When later blocks @@ -3413,8 +3415,10 @@ static int make_request(struct request_queue *q, struct bio * bi) for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { DEFINE_WAIT(w); int disks, data_disks; + int previous; retry: + previous = 0; prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); if (likely(conf->expand_progress == MaxSector)) disks = conf->raid_disks; @@ -3429,9 +3433,10 @@ static int make_request(struct request_queue *q, struct bio * bi) */ spin_lock_irq(&conf->device_lock); disks = conf->raid_disks; - if (logical_sector >= conf->expand_progress) + if (logical_sector >= conf->expand_progress) { disks = conf->previous_raid_disks; - else { + previous = 1; + } else { if (logical_sector >= conf->expand_lo) { spin_unlock_irq(&conf->device_lock); schedule(); @@ -3448,7 +3453,8 @@ static int make_request(struct request_queue *q, struct bio * bi) (unsigned long long)new_sector, (unsigned long long)logical_sector); - sh = get_active_stripe(conf, new_sector, disks, pd_idx, (bi->bi_rw&RWA_MASK)); + sh = get_active_stripe(conf, new_sector, previous, + (bi->bi_rw&RWA_MASK)); if (sh) { if (unlikely(conf->expand_progress != MaxSector)) { /* expansion might have moved on while waiting for a @@ -3582,9 +3588,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { int j; int skipped = 0; - pd_idx = stripe_to_pdidx(sector_nr+i, conf, conf->raid_disks); - sh = get_active_stripe(conf, sector_nr+i, - conf->raid_disks, pd_idx, 0); + sh = get_active_stripe(conf, sector_nr+i, 0, 0); set_bit(STRIPE_EXPANDING, &sh->state); atomic_inc(&conf->reshape_stripes); /* If any of this stripe is beyond the end of the old @@ -3632,10 +3636,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped if (last_sector >= mddev->dev_sectors) last_sector = mddev->dev_sectors - 1; while (first_sector <= last_sector) { - pd_idx = stripe_to_pdidx(first_sector, conf, - conf->previous_raid_disks); - sh = get_active_stripe(conf, first_sector, - conf->previous_raid_disks, pd_idx, 0); + sh = get_active_stripe(conf, first_sector, 1, 0); set_bit(STRIPE_EXPAND_SOURCE, &sh->state); set_bit(STRIPE_HANDLE, &sh->state); release_stripe(sh); @@ -3725,9 +3726,9 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski bitmap_cond_end_sync(mddev->bitmap, sector_nr); pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks); - sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1); + sh = get_active_stripe(conf, sector_nr, 0, 1); if (sh == NULL) { - sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 0); + sh = get_active_stripe(conf, sector_nr, 0, 0); /* make sure we don't swamp the stripe cache if someone else * is trying to get access */ @@ -3793,7 +3794,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) /* already done this stripe */ continue; - sh = get_active_stripe(conf, sector, conf->raid_disks, pd_idx, 1); + sh = get_active_stripe(conf, sector, 0, 1); if (!sh) { /* failed to get a stripe - must wait */ -- 2.41.0