block: convert blkdev_issue_flush() to use empty barriers
[pandora-kernel.git] / drivers / md / raid5.c
index d90ee14..8ee181a 100644 (file)
@@ -108,12 +108,11 @@ static void return_io(struct bio *return_bi)
 {
        struct bio *bi = return_bi;
        while (bi) {
-               int bytes = bi->bi_size;
 
                return_bi = bi->bi_next;
                bi->bi_next = NULL;
                bi->bi_size = 0;
-               bi->bi_end_io(bi, bytes,
+               bi->bi_end_io(bi,
                              test_bit(BIO_UPTODATE, &bi->bi_flags)
                                ? 0 : -EIO);
                bi = return_bi;
@@ -289,7 +288,7 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, in
 }
 
 static void unplug_slaves(mddev_t *mddev);
-static void raid5_unplug_device(request_queue_t *q);
+static void raid5_unplug_device(struct request_queue *q);
 
 static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector, int disks,
                                             int pd_idx, int noblock)
@@ -382,10 +381,10 @@ static unsigned long get_stripe_work(struct stripe_head *sh)
        return pending;
 }
 
-static int
-raid5_end_read_request(struct bio *bi, unsigned int bytes_done, int error);
-static int
-raid5_end_write_request (struct bio *bi, unsigned int bytes_done, int error);
+static void
+raid5_end_read_request(struct bio *bi, int error);
+static void
+raid5_end_write_request(struct bio *bi, int error);
 
 static void ops_run_io(struct stripe_head *sh)
 {
@@ -514,7 +513,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
        struct stripe_head *sh = stripe_head_ref;
        struct bio *return_bi = NULL;
        raid5_conf_t *conf = sh->raid_conf;
-       int i, more_to_read = 0;
+       int i;
 
        pr_debug("%s: stripe %llu\n", __FUNCTION__,
                (unsigned long long)sh->sector);
@@ -522,16 +521,14 @@ static void ops_complete_biofill(void *stripe_head_ref)
        /* clear completed biofills */
        for (i = sh->disks; i--; ) {
                struct r5dev *dev = &sh->dev[i];
-               /* check if this stripe has new incoming reads */
-               if (dev->toread)
-                       more_to_read++;
 
                /* acknowledge completion of a biofill operation */
-               /* and check if we need to reply to a read request
-               */
-               if (test_bit(R5_Wantfill, &dev->flags) && !dev->toread) {
+               /* and check if we need to reply to a read request,
+                * new R5_Wantfill requests are held off until
+                * !test_bit(STRIPE_OP_BIOFILL, &sh->ops.pending)
+                */
+               if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
                        struct bio *rbi, *rbi2;
-                       clear_bit(R5_Wantfill, &dev->flags);
 
                        /* The access to dev->read is outside of the
                         * spin_lock_irq(&conf->device_lock), but is protected
@@ -558,8 +555,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
 
        return_io(return_bi);
 
-       if (more_to_read)
-               set_bit(STRIPE_HANDLE, &sh->state);
+       set_bit(STRIPE_HANDLE, &sh->state);
        release_stripe(sh);
 }
 
@@ -1113,8 +1109,7 @@ static void shrink_stripes(raid5_conf_t *conf)
        conf->slab_cache = NULL;
 }
 
-static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
-                                  int error)
+static void raid5_end_read_request(struct bio * bi, int error)
 {
        struct stripe_head *sh = bi->bi_private;
        raid5_conf_t *conf = sh->raid_conf;
@@ -1123,8 +1118,6 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
        char b[BDEVNAME_SIZE];
        mdk_rdev_t *rdev;
 
-       if (bi->bi_size)
-               return 1;
 
        for (i=0 ; i<disks; i++)
                if (bi == &sh->dev[i].req)
@@ -1135,7 +1128,7 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
                uptodate);
        if (i == disks) {
                BUG();
-               return 0;
+               return;
        }
 
        if (uptodate) {
@@ -1188,20 +1181,15 @@ static int raid5_end_read_request(struct bio * bi, unsigned int bytes_done,
        clear_bit(R5_LOCKED, &sh->dev[i].flags);
        set_bit(STRIPE_HANDLE, &sh->state);
        release_stripe(sh);
-       return 0;
 }
 
-static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
-                                   int error)
+static void raid5_end_write_request (struct bio *bi, int error)
 {
        struct stripe_head *sh = bi->bi_private;
        raid5_conf_t *conf = sh->raid_conf;
        int disks = sh->disks, i;
        int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
 
-       if (bi->bi_size)
-               return 1;
-
        for (i=0 ; i<disks; i++)
                if (bi == &sh->dev[i].req)
                        break;
@@ -1211,7 +1199,7 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
                uptodate);
        if (i == disks) {
                BUG();
-               return 0;
+               return;
        }
 
        if (!uptodate)
@@ -1222,7 +1210,6 @@ static int raid5_end_write_request (struct bio *bi, unsigned int bytes_done,
        clear_bit(R5_LOCKED, &sh->dev[i].flags);
        set_bit(STRIPE_HANDLE, &sh->state);
        release_stripe(sh);
-       return 0;
 }
 
 
@@ -2541,7 +2528,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
        struct dma_async_tx_descriptor *tx = NULL;
        clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
        for (i = 0; i < sh->disks; i++)
-               if (i != sh->pd_idx && (r6s && i != r6s->qd_idx)) {
+               if (i != sh->pd_idx && (!r6s || i != r6s->qd_idx)) {
                        int dd_idx, pd_idx, j;
                        struct stripe_head *sh2;
 
@@ -2574,7 +2561,8 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
                        set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
                        for (j = 0; j < conf->raid_disks; j++)
                                if (j != sh2->pd_idx &&
-                                   (r6s && j != r6s->qd_idx) &&
+                                   (!r6s || j != raid6_next_disk(sh2->pd_idx,
+                                                                sh2->disks)) &&
                                    !test_bit(R5_Expanded, &sh2->dev[j].flags))
                                        break;
                        if (j == conf->raid_disks) {
@@ -2583,12 +2571,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
                        }
                        release_stripe(sh2);
 
-                       /* done submitting copies, wait for them to complete */
-                       if (i + 1 >= sh->disks) {
-                               async_tx_ack(tx);
-                               dma_wait_for_async_tx(tx);
-                       }
                }
+       /* done submitting copies, wait for them to complete */
+       if (tx) {
+               async_tx_ack(tx);
+               dma_wait_for_async_tx(tx);
+       }
 }
 
 /*
@@ -2855,7 +2843,7 @@ static void handle_stripe5(struct stripe_head *sh)
                sh->disks = conf->raid_disks;
                sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
                        conf->raid_disks);
-               s.locked += handle_write_operations5(sh, 0, 1);
+               s.locked += handle_write_operations5(sh, 1, 1);
        } else if (s.expanded &&
                !test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
                clear_bit(STRIPE_EXPAND_READY, &sh->state);
@@ -3182,7 +3170,7 @@ static void unplug_slaves(mddev_t *mddev)
        for (i=0; i<mddev->raid_disks; i++) {
                mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
-                       request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
+                       struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
 
                        atomic_inc(&rdev->nr_pending);
                        rcu_read_unlock();
@@ -3197,7 +3185,7 @@ static void unplug_slaves(mddev_t *mddev)
        rcu_read_unlock();
 }
 
-static void raid5_unplug_device(request_queue_t *q)
+static void raid5_unplug_device(struct request_queue *q)
 {
        mddev_t *mddev = q->queuedata;
        raid5_conf_t *conf = mddev_to_conf(mddev);
@@ -3216,36 +3204,6 @@ static void raid5_unplug_device(request_queue_t *q)
        unplug_slaves(mddev);
 }
 
-static int raid5_issue_flush(request_queue_t *q, struct gendisk *disk,
-                            sector_t *error_sector)
-{
-       mddev_t *mddev = q->queuedata;
-       raid5_conf_t *conf = mddev_to_conf(mddev);
-       int i, ret = 0;
-
-       rcu_read_lock();
-       for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-               mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
-               if (rdev && !test_bit(Faulty, &rdev->flags)) {
-                       struct block_device *bdev = rdev->bdev;
-                       request_queue_t *r_queue = bdev_get_queue(bdev);
-
-                       if (!r_queue->issue_flush_fn)
-                               ret = -EOPNOTSUPP;
-                       else {
-                               atomic_inc(&rdev->nr_pending);
-                               rcu_read_unlock();
-                               ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-                                                             error_sector);
-                               rdev_dec_pending(rdev, mddev);
-                               rcu_read_lock();
-                       }
-               }
-       }
-       rcu_read_unlock();
-       return ret;
-}
-
 static int raid5_congested(void *data, int bits)
 {
        mddev_t *mddev = data;
@@ -3267,7 +3225,7 @@ static int raid5_congested(void *data, int bits)
 /* We want read requests to align with chunks where possible,
  * but write requests don't need to.
  */
-static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
+static int raid5_mergeable_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *biovec)
 {
        mddev_t *mddev = q->queuedata;
        sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
@@ -3342,7 +3300,7 @@ static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
  *  first).
  *  If the read failed..
  */
-static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error)
+static void raid5_align_endio(struct bio *bi, int error)
 {
        struct bio* raid_bi  = bi->bi_private;
        mddev_t *mddev;
@@ -3350,8 +3308,6 @@ static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error)
        int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
        mdk_rdev_t *rdev;
 
-       if (bi->bi_size)
-               return 1;
        bio_put(bi);
 
        mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
@@ -3362,22 +3318,21 @@ static int raid5_align_endio(struct bio *bi, unsigned int bytes, int error)
        rdev_dec_pending(rdev, conf->mddev);
 
        if (!error && uptodate) {
-               bio_endio(raid_bi, bytes, 0);
+               bio_endio(raid_bi, 0);
                if (atomic_dec_and_test(&conf->active_aligned_reads))
                        wake_up(&conf->wait_for_stripe);
-               return 0;
+               return;
        }
 
 
        pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
 
        add_bio_to_retry(raid_bi, conf);
-       return 0;
 }
 
 static int bio_fits_rdev(struct bio *bi)
 {
-       request_queue_t *q = bdev_get_queue(bi->bi_bdev);
+       struct request_queue *q = bdev_get_queue(bi->bi_bdev);
 
        if ((bi->bi_size>>9) > q->max_sectors)
                return 0;
@@ -3396,7 +3351,7 @@ static int bio_fits_rdev(struct bio *bi)
 }
 
 
-static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
+static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
 {
        mddev_t *mddev = q->queuedata;
        raid5_conf_t *conf = mddev_to_conf(mddev);
@@ -3466,7 +3421,7 @@ static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
 }
 
 
-static int make_request(request_queue_t *q, struct bio * bi)
+static int make_request(struct request_queue *q, struct bio * bi)
 {
        mddev_t *mddev = q->queuedata;
        raid5_conf_t *conf = mddev_to_conf(mddev);
@@ -3478,7 +3433,7 @@ static int make_request(request_queue_t *q, struct bio * bi)
        int remaining;
 
        if (unlikely(bio_barrier(bi))) {
-               bio_endio(bi, bi->bi_size, -EOPNOTSUPP);
+               bio_endio(bi, -EOPNOTSUPP);
                return 0;
        }
 
@@ -3594,12 +3549,11 @@ static int make_request(request_queue_t *q, struct bio * bi)
        remaining = --bi->bi_phys_segments;
        spin_unlock_irq(&conf->device_lock);
        if (remaining == 0) {
-               int bytes = bi->bi_size;
 
                if ( rw == WRITE )
                        md_write_end(mddev);
-               bi->bi_size = 0;
-               bi->bi_end_io(bi, bytes,
+
+               bi->bi_end_io(bi,
                              test_bit(BIO_UPTODATE, &bi->bi_flags)
                                ? 0 : -EIO);
        }
@@ -3877,10 +3831,8 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
        remaining = --raid_bio->bi_phys_segments;
        spin_unlock_irq(&conf->device_lock);
        if (remaining == 0) {
-               int bytes = raid_bio->bi_size;
 
-               raid_bio->bi_size = 0;
-               raid_bio->bi_end_io(raid_bio, bytes,
+               raid_bio->bi_end_io(raid_bio,
                              test_bit(BIO_UPTODATE, &raid_bio->bi_flags)
                                ? 0 : -EIO);
        }
@@ -4281,7 +4233,6 @@ static int run(mddev_t *mddev)
                       mdname(mddev));
 
        mddev->queue->unplug_fn = raid5_unplug_device;
-       mddev->queue->issue_flush_fn = raid5_issue_flush;
        mddev->queue->backing_dev_info.congested_data = mddev;
        mddev->queue->backing_dev_info.congested_fn = raid5_congested;