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md/raid5: simplify interface for init_stripe and get_active_stripe

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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 <neilb@suse.de>
This commit is contained in:
NeilBrown 2009-03-31 14:39:38 +11:00
parent dd8ac336c1
commit b5663ba405
1 changed files with 22 additions and 21 deletions
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43
drivers/md/raid5.c
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@ -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 */