Merge branch 'master' into upstream

[linux-2.6] / drivers / md / raid1.c

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6081941de1b34d83ec2fed6384fca4eb43e2604f..4070eff6f0f8aca1d1c931a1505431c3d6cc1a2b 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -315,10 +315,11 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
                if (r1_bio->bios[mirror] == bio)
                        break;
 
-       if (error == -ENOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
+       if (error == -EOPNOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
                set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
                set_bit(R1BIO_BarrierRetry, &r1_bio->state);
                r1_bio->mddev->barriers_work = 0;
+               /* Don't rdev_dec_pending in this branch - keep it for the retry */
        } else {
                /*
                 * this branch is our 'one mirror IO has finished' event handler:
@@ -365,6 +366,7 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
                                }
                        }
                }
+               rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
        }
        /*
         *
@@ -374,11 +376,9 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
        if (atomic_dec_and_test(&r1_bio->remaining)) {
                if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
                        reschedule_retry(r1_bio);
-                       /* Don't dec_pending yet, we want to hold
-                        * the reference over the retry
-                        */
                        goto out;
                }
+               /* it really is the end of this request */
                if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
                        /* free extra copy of the data pages */
                        int i = bio->bi_vcnt;
@@ -393,8 +393,6 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
                md_write_end(r1_bio->mddev);
                raid_end_bio_io(r1_bio);
        }
-
-       rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
  out:
        if (to_put)
                bio_put(to_put);
@@ -753,18 +751,24 @@ static int make_request(request_queue_t *q, struct bio * bio)
        const int rw = bio_data_dir(bio);
        int do_barriers;
 
-       if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
-               bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
-               return 0;
-       }
-
        /*
         * Register the new request and wait if the reconstruction
         * thread has put up a bar for new requests.
         * Continue immediately if no resync is active currently.
+        * We test barriers_work *after* md_write_start as md_write_start
+        * may cause the first superblock write, and that will check out
+        * if barriers work.
         */
+
        md_write_start(mddev, bio); /* wait on superblock update early */
 
+       if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
+               if (rw == WRITE)
+                       md_write_end(mddev);
+               bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+               return 0;
+       }
+
        wait_barrier(conf);
 
        disk_stat_inc(mddev->gendisk, ios[rw]);
@@ -1404,10 +1408,11 @@ static void raid1d(mddev_t *mddev)
                        unplug = 1;
                } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
                        /* some requests in the r1bio were BIO_RW_BARRIER
-                        * requests which failed with -ENOTSUPP.  Hohumm..
+                        * requests which failed with -EOPNOTSUPP.  Hohumm..
                         * Better resubmit without the barrier.
                         * We know which devices to resubmit for, because
                         * all others have had their bios[] entry cleared.
+                        * We already have a nr_pending reference on these rdevs.
                         */
                        int i;
                        clear_bit(R1BIO_BarrierRetry, &r1_bio->state);