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-rw-r--r--drivers/md/raid5.c66
1 files changed, 51 insertions, 15 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 224de022e7c5..05b22925cce4 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -101,6 +101,40 @@
const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
#endif
+/*
+ * We maintain a biased count of active stripes in the bottom 8 bits of
+ * bi_phys_segments, and a count of processed stripes in the upper 8 bits
+ */
+static inline int raid5_bi_phys_segments(struct bio *bio)
+{
+ return bio->bi_phys_segments & 0xff;
+}
+
+static inline int raid5_bi_hw_segments(struct bio *bio)
+{
+ return (bio->bi_phys_segments >> 8) & 0xff;
+}
+
+static inline int raid5_dec_bi_phys_segments(struct bio *bio)
+{
+ --bio->bi_phys_segments;
+ return raid5_bi_phys_segments(bio);
+}
+
+static inline int raid5_dec_bi_hw_segments(struct bio *bio)
+{
+ unsigned short val = raid5_bi_hw_segments(bio);
+
+ --val;
+ bio->bi_phys_segments = (val << 8) | raid5_bi_phys_segments(bio);
+ return val;
+}
+
+static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
+{
+ bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 8);
+}
+
static inline int raid6_next_disk(int disk, int raid_disks)
{
disk++;
@@ -507,7 +541,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
while (rbi && rbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
rbi2 = r5_next_bio(rbi, dev->sector);
- if (--rbi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(rbi)) {
rbi->bi_next = return_bi;
return_bi = rbi;
}
@@ -1725,7 +1759,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
if (*bip)
bi->bi_next = *bip;
*bip = bi;
- bi->bi_phys_segments ++;
+ bi->bi_phys_segments++;
spin_unlock_irq(&conf->device_lock);
spin_unlock(&sh->lock);
@@ -1819,7 +1853,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
sh->dev[i].sector + STRIPE_SECTORS) {
struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(bi)) {
md_write_end(conf->mddev);
bi->bi_next = *return_bi;
*return_bi = bi;
@@ -1834,7 +1868,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
sh->dev[i].sector + STRIPE_SECTORS) {
struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(bi)) {
md_write_end(conf->mddev);
bi->bi_next = *return_bi;
*return_bi = bi;
@@ -1858,7 +1892,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
struct bio *nextbi =
r5_next_bio(bi, sh->dev[i].sector);
clear_bit(BIO_UPTODATE, &bi->bi_flags);
- if (--bi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(bi)) {
bi->bi_next = *return_bi;
*return_bi = bi;
}
@@ -2033,7 +2067,7 @@ static void handle_stripe_clean_event(raid5_conf_t *conf,
while (wbi && wbi->bi_sector <
dev->sector + STRIPE_SECTORS) {
wbi2 = r5_next_bio(wbi, dev->sector);
- if (--wbi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(wbi)) {
md_write_end(conf->mddev);
wbi->bi_next = *return_bi;
*return_bi = wbi;
@@ -2814,7 +2848,7 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
copy_data(0, rbi, dev->page, dev->sector);
rbi2 = r5_next_bio(rbi, dev->sector);
spin_lock_irq(&conf->device_lock);
- if (--rbi->bi_phys_segments == 0) {
+ if (!raid5_dec_bi_phys_segments(rbi)) {
rbi->bi_next = return_bi;
return_bi = rbi;
}
@@ -3155,8 +3189,11 @@ static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
if(bi) {
conf->retry_read_aligned_list = bi->bi_next;
bi->bi_next = NULL;
+ /*
+ * this sets the active strip count to 1 and the processed
+ * strip count to zero (upper 8 bits)
+ */
bi->bi_phys_segments = 1; /* biased count of active stripes */
- bi->bi_hw_segments = 0; /* count of processed stripes */
}
return bi;
@@ -3206,8 +3243,7 @@ static int bio_fits_rdev(struct bio *bi)
if ((bi->bi_size>>9) > q->max_sectors)
return 0;
blk_recount_segments(q, bi);
- if (bi->bi_phys_segments > q->max_phys_segments ||
- bi->bi_hw_segments > q->max_hw_segments)
+ if (bi->bi_phys_segments > q->max_phys_segments)
return 0;
if (q->merge_bvec_fn)
@@ -3468,7 +3504,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
}
spin_lock_irq(&conf->device_lock);
- remaining = --bi->bi_phys_segments;
+ remaining = raid5_dec_bi_phys_segments(bi);
spin_unlock_irq(&conf->device_lock);
if (remaining == 0) {
@@ -3752,7 +3788,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
sector += STRIPE_SECTORS,
scnt++) {
- if (scnt < raid_bio->bi_hw_segments)
+ if (scnt < raid5_bi_hw_segments(raid_bio))
/* already done this stripe */
continue;
@@ -3760,7 +3796,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
if (!sh) {
/* failed to get a stripe - must wait */
- raid_bio->bi_hw_segments = scnt;
+ raid5_set_bi_hw_segments(raid_bio, scnt);
conf->retry_read_aligned = raid_bio;
return handled;
}
@@ -3768,7 +3804,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
release_stripe(sh);
- raid_bio->bi_hw_segments = scnt;
+ raid5_set_bi_hw_segments(raid_bio, scnt);
conf->retry_read_aligned = raid_bio;
return handled;
}
@@ -3778,7 +3814,7 @@ static int retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
handled++;
}
spin_lock_irq(&conf->device_lock);
- remaining = --raid_bio->bi_phys_segments;
+ remaining = raid5_dec_bi_phys_segments(raid_bio);
spin_unlock_irq(&conf->device_lock);
if (remaining == 0)
bio_endio(raid_bio, 0);
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