--- /dev/null
+From 911d4ee8536d89ea8a6cd3e96b1c95a3ebc5ea66 Mon Sep 17 00:00:00 2001
+From: NeilBrown <neilb@suse.de>
+Date: Tue, 31 Mar 2009 14:39:38 +1100
+Subject: [PATCH] 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 <neilb@suse.de>
+---
+ drivers/md/raid5.c | 118 ++++++++++++++++++++++++++---------------------------
+ 1 file changed, 58 insertions(+), 60 deletions(-)
+
+--- linux-2.6.27-SLE11_BRANCH.orig/drivers/md/raid5.c
++++ linux-2.6.27-SLE11_BRANCH/drivers/md/raid5.c
+@@ -301,14 +301,13 @@ static int grow_buffers(struct stripe_he
+ }
+
+ 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));
+@@ -322,8 +321,7 @@ static void init_stripe(struct stripe_he
+
+ 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;
+
+
+@@ -1264,12 +1262,13 @@ static void error(mddev_t *mddev, mdk_rd
+ * 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
+@@ -1298,30 +1297,30 @@ static sector_t raid5_compute_sector(rai
+ /*
+ * 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",
+@@ -1333,32 +1332,32 @@ static sector_t raid5_compute_sector(rai
+ /**** 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",
+@@ -1367,6 +1366,10 @@ static sector_t raid5_compute_sector(rai
+ break;
+ }
+
++ if (sh) {
++ sh->pd_idx = pd_idx;
++ sh->qd_idx = qd_idx;
++ }
+ /*
+ * Finally, compute the new sector number
+ */
+@@ -1384,8 +1387,9 @@ static sector_t compute_blocknr(struct s
+ 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);
+@@ -1448,8 +1452,9 @@ static sector_t compute_blocknr(struct s
+
+ 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;
+ }
+@@ -1845,11 +1850,11 @@ 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;
+
+@@ -1857,8 +1862,7 @@ static int stripe_to_pdidx(sector_t stri
+ 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
+@@ -2516,13 +2520,12 @@ static void handle_stripe_expansion(raid
+ 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
+@@ -2806,11 +2809,9 @@ static bool handle_stripe5(struct stripe
+
+ 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);
+@@ -3027,10 +3028,8 @@ static bool handle_stripe6(struct stripe
+
+ 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);
+@@ -3302,7 +3301,7 @@ static int chunk_aligned_read(struct req
+ {
+ 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;
+
+@@ -3327,7 +3326,7 @@ static int chunk_aligned_read(struct req
+ */
+ 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);
+@@ -3419,7 +3418,7 @@ static int make_request(struct request_q
+ {
+ 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;
+@@ -3483,7 +3482,7 @@ static int make_request(struct request_q
+
+ 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
+ */
+ 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
+ */
+ 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->size<<1))
+ last_sector = (mddev->size<<1)-1;
+ while (first_sector <= last_sector) {
+@@ -3801,7 +3799,7 @@ static int retry_aligned_read(raid5_con
+ * 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_con
+
+ 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;
projects / people / pmueller / ipfire-2.x.git / blobdiff