diff options
Diffstat (limited to 'drivers/md/raid1.c')
| -rw-r--r-- | drivers/md/raid1.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 2e08e48..cb2da87 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -857,6 +857,15 @@ static int make_request(mddev_t *mddev, struct bio * bio) } mirror = conf->mirrors + rdisk; + if (test_bit(WriteMostly, &mirror->rdev->flags) && + bitmap) { + /* Reading from a write-mostly device must + * take care not to over-take any writes + * that are 'behind' + */ + wait_event(bitmap->behind_wait, + atomic_read(&bitmap->behind_writes) == 0); + } r1_bio->read_disk = rdisk; read_bio = bio_clone(bio, GFP_NOIO); @@ -934,10 +943,14 @@ static int make_request(mddev_t *mddev, struct bio * bio) set_bit(R1BIO_Degraded, &r1_bio->state); } - /* do behind I/O ? */ + /* do behind I/O ? + * Not if there are too many, or cannot allocate memory, + * or a reader on WriteMostly is waiting for behind writes + * to flush */ if (bitmap && (atomic_read(&bitmap->behind_writes) < mddev->bitmap_info.max_write_behind) && + !waitqueue_active(&bitmap->behind_wait) && (behind_pages = alloc_behind_pages(bio)) != NULL) set_bit(R1BIO_BehindIO, &r1_bio->state); @@ -2144,15 +2157,13 @@ static int stop(mddev_t *mddev) { conf_t *conf = mddev->private; struct bitmap *bitmap = mddev->bitmap; - int behind_wait = 0; /* wait for behind writes to complete */ - while (bitmap && atomic_read(&bitmap->behind_writes) > 0) { - behind_wait++; - printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule_timeout(HZ); /* wait a second */ + if (bitmap && atomic_read(&bitmap->behind_writes) > 0) { + printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop.\n", mdname(mddev)); /* need to kick something here to make sure I/O goes? */ + wait_event(bitmap->behind_wait, + atomic_read(&bitmap->behind_writes) == 0); } raise_barrier(conf); |