Allocates extra data for activate_stripes and processed_stripes
accounting. Don't need to abuse bio->bi_phys_segments.
Signed-off-by: Shaohua Li <shli@xxxxxx>
---
drivers/md/raid5.c | 12 ++++++++----
drivers/md/raid5.h | 37 +++++++++++++++++++------------------
2 files changed, 27 insertions(+), 22 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b0d1345..fd3e5ce 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3103,7 +3103,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx,
(unsigned long long)sh->sector);
/*
- * If several bio share a stripe. The bio bi_phys_segments acts as a
+ * If several bio share a stripe. The raid5_bio_data has a
* reference count to avoid race. The reference count should already be
* increased before this function is called (for example, in
* raid5_make_request()), so other bio sharing this stripe will not free the
@@ -5146,6 +5146,7 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
if (sectors < bio_sectors(raid_bio)) {
split = bio_split(raid_bio, sectors, GFP_NOIO, fs_bio_set);
bio_chain(split, raid_bio);
+ md_bio_attach_data(mddev, split);
} else
split = raid_bio;
@@ -5335,7 +5336,7 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi)
last_sector = bi->bi_iter.bi_sector + (bi->bi_iter.bi_size>>9);
bi->bi_next = NULL;
- bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
+ raid5_set_bi_stripes(bi, 1);
stripe_sectors = conf->chunk_sectors *
(conf->raid_disks - conf->max_degraded);
@@ -5463,7 +5464,7 @@ static void raid5_make_request(struct mddev *mddev, struct bio * bi)
logical_sector = bi->bi_iter.bi_sector & ~((sector_t)STRIPE_SECTORS-1);
last_sector = bio_end_sector(bi);
bi->bi_next = NULL;
- bi->bi_phys_segments = 1; /* over-loaded to count active stripes */
+ raid5_set_bi_stripes(bi, 1);
prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE);
for (;logical_sector < last_sector; logical_sector += STRIPE_SECTORS) {
@@ -5963,7 +5964,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio)
* We cannot pre-allocate enough stripe_heads as we may need
* more than exist in the cache (if we allow ever large chunks).
* So we do one stripe head at a time and record in
- * ->bi_hw_segments how many have been done.
+ * ->raid5_bio_data.processed_stripes how many have been done.
*
* We *know* that this entire raid_bio is in one chunk, so
* it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
@@ -8188,6 +8189,7 @@ static struct md_personality raid6_personality =
.quiesce = raid5_quiesce,
.takeover = raid6_takeover,
.congested = raid5_congested,
+ .per_bio_data_size = sizeof(struct raid5_bio_data),
};
static struct md_personality raid5_personality =
{
@@ -8211,6 +8213,7 @@ static struct md_personality raid5_personality =
.quiesce = raid5_quiesce,
.takeover = raid5_takeover,
.congested = raid5_congested,
+ .per_bio_data_size = sizeof(struct raid5_bio_data),
};
static struct md_personality raid4_personality =
@@ -8235,6 +8238,7 @@ static struct md_personality raid4_personality =
.quiesce = raid5_quiesce,
.takeover = raid4_takeover,
.congested = raid5_congested,
+ .per_bio_data_size = sizeof(struct raid5_bio_data),
};
static int __init raid5_init(void)
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index c0687df..9232463 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -481,48 +481,49 @@ static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)
return NULL;
}
-/*
- * We maintain a biased count of active stripes in the bottom 16 bits of
- * bi_phys_segments, and a count of processed stripes in the upper 16 bits
- */
+struct raid5_bio_data {
+ atomic_t active_stripes;
+ atomic_t processed_stripes;
+};
+
+#define raid5_get_bio_data(bio) \
+ ((struct raid5_bio_data *)md_get_per_bio_data(bio))
+
static inline int raid5_bi_processed_stripes(struct bio *bio)
{
- atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
+ struct raid5_bio_data *data= raid5_get_bio_data(bio);
- return (atomic_read(segments) >> 16) & 0xffff;
+ return atomic_read(&data->processed_stripes);
}
static inline int raid5_dec_bi_active_stripes(struct bio *bio)
{
- atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
+ struct raid5_bio_data *data= raid5_get_bio_data(bio);
- return atomic_sub_return(1, segments) & 0xffff;
+ return atomic_sub_return(1, &data->active_stripes);
}
static inline void raid5_inc_bi_active_stripes(struct bio *bio)
{
- atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
+ struct raid5_bio_data *data= raid5_get_bio_data(bio);
- atomic_inc(segments);
+ atomic_inc(&data->active_stripes);
}
static inline void raid5_set_bi_processed_stripes(struct bio *bio,
unsigned int cnt)
{
- atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
- int old, new;
+ struct raid5_bio_data *data= raid5_get_bio_data(bio);
- do {
- old = atomic_read(segments);
- new = (old & 0xffff) | (cnt << 16);
- } while (atomic_cmpxchg(segments, old, new) != old);
+ atomic_set(&data->processed_stripes, cnt);
}
static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)
{
- atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;
+ struct raid5_bio_data *data= raid5_get_bio_data(bio);
- atomic_set(segments, cnt);
+ atomic_set(&data->active_stripes, cnt);
+ atomic_set(&data->processed_stripes, 0);
}
/* NOTE NR_STRIPE_HASH_LOCKS must remain below 64.
--
2.9.3
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