diff options
| -rw-r--r-- | drivers/md/bitmap.c | 4 | ||||
| -rw-r--r-- | drivers/md/bitmap.h | 1 | ||||
| -rw-r--r-- | drivers/md/raid1.c | 25 |
3 files changed, 22 insertions, 8 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 49d6080387c8..c9c6a345e17b 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -1356,7 +1356,8 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto { if (!bitmap) return; if (behind) { - atomic_dec(&bitmap->behind_writes); + if (atomic_dec_and_test(&bitmap->behind_writes)) + wake_up(&bitmap->behind_wait); PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n", atomic_read(&bitmap->behind_writes), bitmap->max_write_behind); } @@ -1680,6 +1681,7 @@ int bitmap_create(mddev_t *mddev) atomic_set(&bitmap->pending_writes, 0); init_waitqueue_head(&bitmap->write_wait); init_waitqueue_head(&bitmap->overflow_wait); + init_waitqueue_head(&bitmap->behind_wait); bitmap->mddev = mddev; diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h index aa82b7caa85f..3797dea4723a 100644 --- a/drivers/md/bitmap.h +++ b/drivers/md/bitmap.h @@ -240,6 +240,7 @@ struct bitmap { atomic_t pending_writes; /* pending writes to the bitmap file */ wait_queue_head_t write_wait; wait_queue_head_t overflow_wait; + wait_queue_head_t behind_wait; struct sysfs_dirent *sysfs_can_clear; }; diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 2e08e48b02d9..cb2da87ad593 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); |