block: raid fixups for removal of bi_hw_segments

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 28a3869..0b82030 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1787,7 +1787,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                bio->bi_vcnt = 0;
                bio->bi_idx = 0;
                bio->bi_phys_segments = 0;
-               bio->bi_hw_segments = 0;
                bio->bi_size = 0;
                bio->bi_end_io = NULL;
                bio->bi_private = NULL;

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 0f40688..d3b9aa0 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1944,7 +1944,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                bio->bi_vcnt = 0;
                bio->bi_idx = 0;
                bio->bi_phys_segments = 0;
-               bio->bi_hw_segments = 0;
                bio->bi_size = 0;
        }
 

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 224de02..05b2292 100644 (file)
--- 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);