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md/raid5: Refactor add_stripe_bio()

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Factor out two helper functions from add_stripe_bio(): one to check for
overlap (stripe_bio_overlaps()), and one to actually add the bio to the
stripe (__add_stripe_bio()). The latter function will always succeed.

This will be useful in the next patch so that overlap can be checked for
multiple disks before adding any

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Logan Gunthorpe 2022-06-16 13:19:41 -06:00 committed by Jens Axboe
parent 3312e6c887
commit 4ad1d9849f
1 changed files with 56 additions and 30 deletions
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86
drivers/md/raid5.c
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@ -3416,39 +3416,32 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
s->locked, s->ops_request);
}
/*
* Each stripe/dev can have one or more bion attached.
* toread/towrite point to the first in a chain.
* The bi_next chain must be in order.
*/
static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
int forwrite, int previous)
static bool stripe_bio_overlaps(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite)
{
struct bio **bip;
struct r5conf *conf = sh->raid_conf;
int firstwrite=0;
struct bio **bip;
pr_debug("adding bi b#%llu to stripe s#%llu\n",
(unsigned long long)bi->bi_iter.bi_sector,
(unsigned long long)sh->sector);
pr_debug("checking bi b#%llu to stripe s#%llu\n",
bi->bi_iter.bi_sector, sh->sector);
spin_lock_irq(&sh->stripe_lock);
/* Don't allow new IO added to stripes in batch list */
if (sh->batch_head)
goto overlap;
if (forwrite) {
return true;
if (forwrite)
bip = &sh->dev[dd_idx].towrite;
if (*bip == NULL)
firstwrite = 1;
} else
else
bip = &sh->dev[dd_idx].toread;
while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
goto overlap;
bip = & (*bip)->bi_next;
return true;
bip = &(*bip)->bi_next;
}
if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
goto overlap;
return true;
if (forwrite && raid5_has_ppl(conf)) {
/*
@ -3477,9 +3470,30 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
}
if (first + conf->chunk_sectors * (count - 1) != last)
goto overlap;
return true;
}
return false;
}
static void __add_stripe_bio(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite, int previous)
{
struct r5conf *conf = sh->raid_conf;
struct bio **bip;
int firstwrite = 0;
if (forwrite) {
bip = &sh->dev[dd_idx].towrite;
if (!*bip)
firstwrite = 1;
} else {
bip = &sh->dev[dd_idx].toread;
}
while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector)
bip = &(*bip)->bi_next;
if (!forwrite || previous)
clear_bit(STRIPE_BATCH_READY, &sh->state);
@ -3506,8 +3520,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
}
pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
(unsigned long long)(*bip)->bi_iter.bi_sector,
(unsigned long long)sh->sector, dd_idx);
(*bip)->bi_iter.bi_sector, sh->sector, dd_idx);
if (conf->mddev->bitmap && firstwrite) {
/* Cannot hold spinlock over bitmap_startwrite,
@ -3515,7 +3528,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
* we have added to the bitmap and set bm_seq.
* So set STRIPE_BITMAP_PENDING to prevent
* batching.
* If multiple add_stripe_bio() calls race here they
* If multiple __add_stripe_bio() calls race here they
* much all set STRIPE_BITMAP_PENDING. So only the first one
* to complete "bitmap_startwrite" gets to set
* STRIPE_BIT_DELAY. This is important as once a stripe
@ -3533,14 +3546,27 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
set_bit(STRIPE_BIT_DELAY, &sh->state);
}
}
spin_unlock_irq(&sh->stripe_lock);
}
return 1;
/*
* Each stripe/dev can have one or more bios attached.
* toread/towrite point to the first in a chain.
* The bi_next chain must be in order.
*/
static bool add_stripe_bio(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite, int previous)
{
spin_lock_irq(&sh->stripe_lock);
overlap:
set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
spin_unlock_irq(&sh->stripe_lock);
return false;
}
__add_stripe_bio(sh, bi, dd_idx, forwrite, previous);
spin_unlock_irq(&sh->stripe_lock);
return 0;
return true;
}
static void end_reshape(struct r5conf *conf);