Allocates extra data (an 'unsigned int') for bio reference accounting.
Don't need to abuse bio->bi_phys_segments.
Signed-off-by: Shaohua Li <shli@xxxxxx>
---
drivers/md/raid1.c | 44 +++++++++++++++++++++++++-------------------
1 file changed, 25 insertions(+), 19 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 7b0f647..daa4038 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -102,6 +102,11 @@ static void r1bio_pool_free(void *r1_bio, void *data)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
#define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS)
+static unsigned int *raid1_bio_ref_ptr(struct bio *bio)
+{
+ return md_get_per_bio_data(bio);
+}
+
static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
{
struct pool_info *pi = data;
@@ -246,15 +251,15 @@ static void call_bio_endio(struct r1bio *r1_bio)
sector_t start_next_window = r1_bio->start_next_window;
sector_t bi_sector = bio->bi_iter.bi_sector;
- if (bio->bi_phys_segments) {
+ if (*raid1_bio_ref_ptr(bio)) {
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
- bio->bi_phys_segments--;
- done = (bio->bi_phys_segments == 0);
+ (*raid1_bio_ref_ptr(bio))--;
+ done = (*raid1_bio_ref_ptr(bio) == 0);
spin_unlock_irqrestore(&conf->device_lock, flags);
/*
* make_request() might be waiting for
- * bi_phys_segments to decrease
+ * bio reference count to decrease
*/
wake_up(&conf->wait_barrier);
} else
@@ -1138,10 +1143,10 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
- bio->bi_iter.bi_sector);
r1_bio->sectors = max_sectors;
spin_lock_irq(&conf->device_lock);
- if (bio->bi_phys_segments == 0)
- bio->bi_phys_segments = 2;
+ if (*raid1_bio_ref_ptr(bio) == 0)
+ *raid1_bio_ref_ptr(bio) = 2;
else
- bio->bi_phys_segments++;
+ (*raid1_bio_ref_ptr(bio))++;
spin_unlock_irq(&conf->device_lock);
/*
@@ -1316,13 +1321,13 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
start_next_window = wait_barrier(conf, bio);
/*
* We must make sure the multi r1bios of bio have
- * the same value of bi_phys_segments
+ * the same value of reference count
*/
- if (bio->bi_phys_segments && old &&
+ if (*raid1_bio_ref_ptr(bio) && old &&
old != start_next_window)
/* Wait for the former r1bio(s) to complete */
wait_event(conf->wait_barrier,
- bio->bi_phys_segments == 1);
+ *raid1_bio_ref_ptr(bio) == 1);
goto retry_write;
}
@@ -1332,10 +1337,10 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
*/
r1_bio->sectors = max_sectors;
spin_lock_irq(&conf->device_lock);
- if (bio->bi_phys_segments == 0)
- bio->bi_phys_segments = 2;
+ if (*raid1_bio_ref_ptr(bio) == 0)
+ *raid1_bio_ref_ptr(bio) = 2;
else
- bio->bi_phys_segments++;
+ (*raid1_bio_ref_ptr(bio))++;
spin_unlock_irq(&conf->device_lock);
}
sectors_handled = r1_bio->sector + max_sectors - bio->bi_iter.bi_sector;
@@ -1428,7 +1433,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
if (sectors_handled < bio_sectors(bio)) {
r1_bio_write_done(r1_bio);
/* We need another r1_bio. It has already been counted
- * in bio->bi_phys_segments
+ * in bio reference count
*/
r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
r1_bio->master_bio = bio;
@@ -1466,11 +1471,11 @@ static void raid1_make_request(struct mddev *mddev, struct bio *bio)
/*
* We might need to issue multiple reads to different devices if there
* are bad blocks around, so we keep track of the number of reads in
- * bio->bi_phys_segments. If this is 0, there is only one r1_bio and
+ * bio reference count. If this is 0, there is only one r1_bio and
* no locking will be needed when requests complete. If it is
* non-zero, then it is the number of not-completed requests.
*/
- bio->bi_phys_segments = 0;
+ *raid1_bio_ref_ptr(bio) = 0;
bio_clear_flag(bio, BIO_SEG_VALID);
if (bio_data_dir(bio) == READ)
@@ -2438,10 +2443,10 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
- mbio->bi_iter.bi_sector);
r1_bio->sectors = max_sectors;
spin_lock_irq(&conf->device_lock);
- if (mbio->bi_phys_segments == 0)
- mbio->bi_phys_segments = 2;
+ if (*raid1_bio_ref_ptr(mbio) == 0)
+ *raid1_bio_ref_ptr(mbio) = 2;
else
- mbio->bi_phys_segments++;
+ (*raid1_bio_ref_ptr(mbio))++;
spin_unlock_irq(&conf->device_lock);
trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
bio, bio_dev, bio_sector);
@@ -3289,6 +3294,7 @@ static struct md_personality raid1_personality =
.quiesce = raid1_quiesce,
.takeover = raid1_takeover,
.congested = raid1_congested,
+ .per_bio_data_size = sizeof(unsigned int),
};
static int __init raid_init(void)
--
2.9.3
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