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 <[email protected]>
---
drivers/md/raid5.c | 86 ++++++++++++++++++++++++++++++----------------
1 file changed, 56 insertions(+), 30 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 28ea7b9b6ab6..1fa82d8fa89e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3418,39 +3418,32 @@ 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)) {
/*
@@ -3479,9 +3472,30 @@ 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);
@@ -3508,8 +3522,7 @@ 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,
@@ -3517,7 +3530,7 @@ 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
@@ -3535,14 +3548,27 @@ 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);
--
2.30.2
Looks good:
Reviewed-by: Christoph Hellwig <[email protected]>