From 911d4ee8536d89ea8a6cd3e96b1c95a3ebc5ea66 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 14:39:38 +1100 Subject: md/raid5: simplify raid5_compute_sector interface Rather than passing 'pd_idx' and 'qd_idx' to be filled in, pass a 'struct stripe_head *' and fill in the relevant fields. This is more extensible. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 118 ++++++++++++++++++++++++++--------------------------- 1 file changed, 58 insertions(+), 60 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index cb3e157b52d3..2e2e64f6ef71 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -299,14 +299,13 @@ 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 previous, - int *qd_idx); +static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, + struct stripe_head *sh); static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) { raid5_conf_t *conf = sh->raid_conf; int i; - int qd_idx; BUG_ON(atomic_read(&sh->count) != 0); BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); @@ -320,8 +319,7 @@ static void init_stripe(struct stripe_head *sh, sector_t sector, int previous) sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks; sh->sector = sector; - sh->pd_idx = stripe_to_pdidx(sector, conf, previous, &qd_idx); - sh->qd_idx = qd_idx; + stripe_set_idx(sector, conf, previous, sh); sh->state = 0; @@ -1262,12 +1260,13 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev) * Output: index of the data and parity disk, and the sector # in them. */ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, - int previous, - int *dd_idx, int *pd_idx, int *qd_idx) + int previous, int *dd_idx, + struct stripe_head *sh) { long stripe; unsigned long chunk_number; unsigned int chunk_offset; + int pd_idx, qd_idx; sector_t new_sector; int sectors_per_chunk = conf->chunk_size >> 9; int raid_disks = previous ? conf->previous_raid_disks @@ -1296,30 +1295,30 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, /* * Select the parity disk based on the user selected algorithm. */ - *qd_idx = ~0; + pd_idx = qd_idx = ~0; switch(conf->level) { case 4: - *pd_idx = data_disks; + pd_idx = data_disks; break; case 5: switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: - *pd_idx = data_disks - stripe % raid_disks; - if (*dd_idx >= *pd_idx) + pd_idx = data_disks - stripe % raid_disks; + if (*dd_idx >= pd_idx) (*dd_idx)++; break; case ALGORITHM_RIGHT_ASYMMETRIC: - *pd_idx = stripe % raid_disks; - if (*dd_idx >= *pd_idx) + pd_idx = stripe % raid_disks; + if (*dd_idx >= pd_idx) (*dd_idx)++; break; case ALGORITHM_LEFT_SYMMETRIC: - *pd_idx = data_disks - stripe % raid_disks; - *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; + pd_idx = data_disks - stripe % raid_disks; + *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; break; case ALGORITHM_RIGHT_SYMMETRIC: - *pd_idx = stripe % raid_disks; - *dd_idx = (*pd_idx + 1 + *dd_idx) % raid_disks; + pd_idx = stripe % raid_disks; + *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; break; default: printk(KERN_ERR "raid5: unsupported algorithm %d\n", @@ -1331,32 +1330,32 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, /**** FIX THIS ****/ switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: - *pd_idx = raid_disks - 1 - (stripe % raid_disks); - *qd_idx = *pd_idx + 1; - if (*pd_idx == raid_disks-1) { + pd_idx = raid_disks - 1 - (stripe % raid_disks); + qd_idx = pd_idx + 1; + if (pd_idx == raid_disks-1) { (*dd_idx)++; /* Q D D D P */ - *qd_idx = 0; - } else if (*dd_idx >= *pd_idx) + qd_idx = 0; + } else if (*dd_idx >= pd_idx) (*dd_idx) += 2; /* D D P Q D */ break; case ALGORITHM_RIGHT_ASYMMETRIC: - *pd_idx = stripe % raid_disks; - *qd_idx = *pd_idx + 1; - if (*pd_idx == raid_disks-1) { + pd_idx = stripe % raid_disks; + qd_idx = pd_idx + 1; + if (pd_idx == raid_disks-1) { (*dd_idx)++; /* Q D D D P */ - *qd_idx = 0; - } else if (*dd_idx >= *pd_idx) + qd_idx = 0; + } else if (*dd_idx >= pd_idx) (*dd_idx) += 2; /* D D P Q D */ break; case ALGORITHM_LEFT_SYMMETRIC: - *pd_idx = raid_disks - 1 - (stripe % raid_disks); - *qd_idx = (*pd_idx + 1) % raid_disks; - *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; + pd_idx = raid_disks - 1 - (stripe % raid_disks); + qd_idx = (pd_idx + 1) % raid_disks; + *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; break; case ALGORITHM_RIGHT_SYMMETRIC: - *pd_idx = stripe % raid_disks; - *qd_idx = (*pd_idx + 1) % raid_disks; - *dd_idx = (*pd_idx + 2 + *dd_idx) % raid_disks; + pd_idx = stripe % raid_disks; + qd_idx = (pd_idx + 1) % raid_disks; + *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; break; default: printk(KERN_CRIT "raid6: unsupported algorithm %d\n", @@ -1365,6 +1364,10 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, break; } + if (sh) { + sh->pd_idx = pd_idx; + sh->qd_idx = qd_idx; + } /* * Finally, compute the new sector number */ @@ -1382,8 +1385,9 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) int sectors_per_chunk = conf->chunk_size >> 9; sector_t stripe; int chunk_offset; - int chunk_number, dummy1, dummy2, dummy3, dd_idx = i; + int chunk_number, dummy1, dd_idx = i; sector_t r_sector; + struct stripe_head sh2; chunk_offset = sector_div(new_sector, sectors_per_chunk); @@ -1446,8 +1450,9 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) check = raid5_compute_sector(conf, r_sector, (raid_disks != conf->raid_disks), - &dummy1, &dummy2, &dummy3); - if (check != sh->sector || dummy1 != dd_idx || dummy2 != sh->pd_idx) { + &dummy1, &sh2); + if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx + || sh2.qd_idx != sh->qd_idx) { printk(KERN_ERR "compute_blocknr: map not correct\n"); return 0; } @@ -1843,11 +1848,11 @@ static int page_is_zero(struct page *p) memcmp(a, a+4, STRIPE_SIZE-4)==0); } -static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int previous, - int *qd_idxp) +static void stripe_set_idx(sector_t stripe, raid5_conf_t *conf, int previous, + struct stripe_head *sh) { int sectors_per_chunk = conf->chunk_size >> 9; - int pd_idx, dd_idx; + int dd_idx; int chunk_offset = sector_div(stripe, sectors_per_chunk); int disks = previous ? conf->previous_raid_disks : conf->raid_disks; @@ -1855,8 +1860,7 @@ static int stripe_to_pdidx(sector_t stripe, raid5_conf_t *conf, int previous, stripe * (disks - conf->max_degraded) *sectors_per_chunk + chunk_offset, previous, - &dd_idx, &pd_idx, qd_idxp); - return pd_idx; + &dd_idx, sh); } static void @@ -2514,13 +2518,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh, clear_bit(STRIPE_EXPAND_SOURCE, &sh->state); for (i = 0; i < sh->disks; i++) if (i != sh->pd_idx && (!r6s || i != r6s->qd_idx)) { - int dd_idx, pd_idx, qd_idx, j; + int dd_idx, j; struct stripe_head *sh2; sector_t bn = compute_blocknr(sh, i); - sector_t s = - raid5_compute_sector(conf, bn, 0, - &dd_idx, &pd_idx, &qd_idx); + sector_t s = raid5_compute_sector(conf, bn, 0, + &dd_idx, NULL); sh2 = get_active_stripe(conf, s, 0, 1); if (sh2 == NULL) /* so far only the early blocks of this stripe @@ -2804,11 +2807,9 @@ static bool handle_stripe5(struct stripe_head *sh) if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) && !sh->reconstruct_state) { - int qd_idx; /* Need to write out all blocks after computing parity */ sh->disks = conf->raid_disks; - sh->pd_idx = stripe_to_pdidx(sh->sector, conf, 0, &qd_idx); - sh->qd_idx = qd_idx; + stripe_set_idx(sh->sector, conf, 0, sh); schedule_reconstruction5(sh, &s, 1, 1); } else if (s.expanded && !sh->reconstruct_state && s.locked == 0) { clear_bit(STRIPE_EXPAND_READY, &sh->state); @@ -3025,10 +3026,8 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page) if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { /* Need to write out all blocks after computing P&Q */ - int qd_idx; sh->disks = conf->raid_disks; - sh->pd_idx = stripe_to_pdidx(sh->sector, conf, 0, &qd_idx); - sh->qd_idx = qd_idx; + 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); @@ -3300,7 +3299,7 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) { mddev_t *mddev = q->queuedata; raid5_conf_t *conf = mddev_to_conf(mddev); - unsigned int dd_idx, pd_idx, qd_idx; + unsigned int dd_idx; struct bio* align_bi; mdk_rdev_t *rdev; @@ -3325,7 +3324,7 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) */ align_bi->bi_sector = raid5_compute_sector(conf, raid_bio->bi_sector, 0, - &dd_idx, &pd_idx, &qd_idx); + &dd_idx, NULL); rcu_read_lock(); rdev = rcu_dereference(conf->disks[dd_idx].rdev); @@ -3417,7 +3416,7 @@ static int make_request(struct request_queue *q, struct bio * bi) { mddev_t *mddev = q->queuedata; raid5_conf_t *conf = mddev_to_conf(mddev); - int dd_idx, pd_idx, qd_idx; + int dd_idx; sector_t new_sector; sector_t logical_sector, last_sector; struct stripe_head *sh; @@ -3484,7 +3483,7 @@ static int make_request(struct request_queue *q, struct bio * bi) new_sector = raid5_compute_sector(conf, logical_sector, previous, - &dd_idx, &pd_idx, &qd_idx); + &dd_idx, NULL); pr_debug("raid5: make_request, sector %llu logical %llu\n", (unsigned long long)new_sector, (unsigned long long)logical_sector); @@ -3572,7 +3571,6 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped */ raid5_conf_t *conf = (raid5_conf_t *) mddev->private; struct stripe_head *sh; - int pd_idx, qd_idx; sector_t first_sector, last_sector; int raid_disks = conf->previous_raid_disks; int data_disks = raid_disks - conf->max_degraded; @@ -3662,11 +3660,11 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped */ first_sector = raid5_compute_sector(conf, sector_nr*(new_data_disks), - 1, &dd_idx, &pd_idx, &qd_idx); + 1, &dd_idx, NULL); last_sector = raid5_compute_sector(conf, ((sector_nr+conf->chunk_size/512) *(new_data_disks) - 1), - 1, &dd_idx, &pd_idx, &qd_idx); + 1, &dd_idx, NULL); if (last_sector >= mddev->dev_sectors) last_sector = mddev->dev_sectors - 1; while (first_sector <= last_sector) { @@ -3801,7 +3799,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) * it will be only one 'dd_idx' and only need one call to raid5_compute_sector. */ struct stripe_head *sh; - int dd_idx, pd_idx, qd_idx; + int dd_idx; sector_t sector, logical_sector, last_sector; int scnt = 0; int remaining; @@ -3809,7 +3807,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio) logical_sector = raid_bio->bi_sector & ~((sector_t)STRIPE_SECTORS-1); sector = raid5_compute_sector(conf, logical_sector, - 0, &dd_idx, &pd_idx, &qd_idx); + 0, &dd_idx, NULL); last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); for (; logical_sector < last_sector; -- cgit v1.2.2