1 files changed, 174 insertions, 41 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e0913e4..3ab80e9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -125,6 +125,20 @@ static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
 	return NULL;
 }
 
+static void requeue_list(struct btrfs_pending_bios *pending_bios,
+			struct bio *head, struct bio *tail)
+{
+
+	struct bio *old_head;
+
+	old_head = pending_bios->head;
+	pending_bios->head = head;
+	if (pending_bios->tail)
+		tail->bi_next = old_head;
+	else
+		pending_bios->tail = tail;
+}
+
 /*
  * we try to collect pending bios for a device so we don't get a large
  * number of procs sending bios down to the same device.  This greatly
@@ -141,32 +155,49 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
 	struct bio *pending;
 	struct backing_dev_info *bdi;
 	struct btrfs_fs_info *fs_info;
+	struct btrfs_pending_bios *pending_bios;
 	struct bio *tail;
 	struct bio *cur;
 	int again = 0;
-	unsigned long num_run = 0;
+	unsigned long num_run;
+	unsigned long num_sync_run;
+	unsigned long batch_run = 0;
 	unsigned long limit;
 	unsigned long last_waited = 0;
+	int force_reg = 0;
 
 	bdi = blk_get_backing_dev_info(device->bdev);
 	fs_info = device->dev_root->fs_info;
 	limit = btrfs_async_submit_limit(fs_info);
 	limit = limit * 2 / 3;
 
+	/* we want to make sure that every time we switch from the sync
+	 * list to the normal list, we unplug
+	 */
+	num_sync_run = 0;
+
 loop:
 	spin_lock(&device->io_lock);
 
 loop_lock:
+	num_run = 0;
+
 	/* take all the bios off the list at once and process them
 	 * later on (without the lock held).  But, remember the
 	 * tail and other pointers so the bios can be properly reinserted
 	 * into the list if we hit congestion
 	 */
-	pending = device->pending_bios;
-	tail = device->pending_bio_tail;
+	if (!force_reg && device->pending_sync_bios.head) {
+		pending_bios = &device->pending_sync_bios;
+		force_reg = 1;
+	} else {
+		pending_bios = &device->pending_bios;
+		force_reg = 0;
+	}
+
+	pending = pending_bios->head;
+	tail = pending_bios->tail;
 	WARN_ON(pending && !tail);
-	device->pending_bios = NULL;
-	device->pending_bio_tail = NULL;
 
 	/*
 	 * if pending was null this time around, no bios need processing
@@ -176,16 +207,45 @@ loop_lock:
 	 * device->running_pending is used to synchronize with the
 	 * schedule_bio code.
 	 */
-	if (pending) {
-		again = 1;
-		device->running_pending = 1;
-	} else {
+	if (device->pending_sync_bios.head == NULL &&
+	    device->pending_bios.head == NULL) {
 		again = 0;
 		device->running_pending = 0;
+	} else {
+		again = 1;
+		device->running_pending = 1;
 	}
+
+	pending_bios->head = NULL;
+	pending_bios->tail = NULL;
+
 	spin_unlock(&device->io_lock);
 
+	/*
+	 * if we're doing the regular priority list, make sure we unplug
+	 * for any high prio bios we've sent down
+	 */
+	if (pending_bios == &device->pending_bios && num_sync_run > 0) {
+		num_sync_run = 0;
+		blk_run_backing_dev(bdi, NULL);
+	}
+
 	while (pending) {
+
+		rmb();
+		/* we want to work on both lists, but do more bios on the
+		 * sync list than the regular list
+		 */
+		if ((num_run > 32 &&
+		    pending_bios != &device->pending_sync_bios &&
+		    device->pending_sync_bios.head) ||
+		   (num_run > 64 && pending_bios == &device->pending_sync_bios &&
+		    device->pending_bios.head)) {
+			spin_lock(&device->io_lock);
+			requeue_list(pending_bios, pending, tail);
+			goto loop_lock;
+		}
+
 		cur = pending;
 		pending = pending->bi_next;
 		cur->bi_next = NULL;
@@ -196,19 +256,28 @@ loop_lock:
 			wake_up(&fs_info->async_submit_wait);
 
 		BUG_ON(atomic_read(&cur->bi_cnt) == 0);
-		bio_get(cur);
 		submit_bio(cur->bi_rw, cur);
-		bio_put(cur);
 		num_run++;
+		batch_run++;
+
+		if (bio_sync(cur))
+			num_sync_run++;
+
+		if (need_resched()) {
+			if (num_sync_run) {
+				blk_run_backing_dev(bdi, NULL);
+				num_sync_run = 0;
+			}
+			cond_resched();
+		}
 
 		/*
 		 * we made progress, there is more work to do and the bdi
 		 * is now congested.  Back off and let other work structs
 		 * run instead
 		 */
-		if (pending && bdi_write_congested(bdi) && num_run > 16 &&
+		if (pending && bdi_write_congested(bdi) && batch_run > 32 &&
 		    fs_info->fs_devices->open_devices > 1) {
-			struct bio *old_head;
 			struct io_context *ioc;
 
 			ioc = current->io_context;
@@ -233,17 +302,17 @@ loop_lock:
 				 * against it before looping
 				 */
 				last_waited = ioc->last_waited;
+				if (need_resched()) {
+					if (num_sync_run) {
+						blk_run_backing_dev(bdi, NULL);
+						num_sync_run = 0;
+					}
+					cond_resched();
+				}
 				continue;
 			}
 			spin_lock(&device->io_lock);
-
-			old_head = device->pending_bios;
-			device->pending_bios = pending;
-			if (device->pending_bio_tail)
-				tail->bi_next = old_head;
-			else
-				device->pending_bio_tail = tail;
-
+			requeue_list(pending_bios, pending, tail);
 			device->running_pending = 1;
 
 			spin_unlock(&device->io_lock);
@@ -251,11 +320,18 @@ loop_lock:
 			goto done;
 		}
 	}
+
+	if (num_sync_run) {
+		num_sync_run = 0;
+		blk_run_backing_dev(bdi, NULL);
+	}
+
+	cond_resched();
 	if (again)
 		goto loop;
 
 	spin_lock(&device->io_lock);
-	if (device->pending_bios)
+	if (device->pending_bios.head || device->pending_sync_bios.head)
 		goto loop_lock;
 	spin_unlock(&device->io_lock);
 
@@ -301,6 +377,7 @@ static noinline int device_list_add(const char *path,
 		memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
 		fs_devices->latest_devid = devid;
 		fs_devices->latest_trans = found_transid;
+		mutex_init(&fs_devices->device_list_mutex);
 		device = NULL;
 	} else {
 		device = __find_device(&fs_devices->devices, devid,
@@ -327,7 +404,11 @@ static noinline int device_list_add(const char *path,
 			return -ENOMEM;
 		}
 		INIT_LIST_HEAD(&device->dev_alloc_list);
+
+		mutex_lock(&fs_devices->device_list_mutex);
 		list_add(&device->dev_list, &fs_devices->devices);
+		mutex_unlock(&fs_devices->device_list_mutex);
+
 		device->fs_devices = fs_devices;
 		fs_devices->num_devices++;
 	}
@@ -353,10 +434,12 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 	INIT_LIST_HEAD(&fs_devices->devices);
 	INIT_LIST_HEAD(&fs_devices->alloc_list);
 	INIT_LIST_HEAD(&fs_devices->list);
+	mutex_init(&fs_devices->device_list_mutex);
 	fs_devices->latest_devid = orig->latest_devid;
 	fs_devices->latest_trans = orig->latest_trans;
 	memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
 
+	mutex_lock(&orig->device_list_mutex);
 	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
 		device = kzalloc(sizeof(*device), GFP_NOFS);
 		if (!device)
@@ -378,8 +461,10 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 		device->fs_devices = fs_devices;
 		fs_devices->num_devices++;
 	}
+	mutex_unlock(&orig->device_list_mutex);
 	return fs_devices;
 error:
+	mutex_unlock(&orig->device_list_mutex);
 	free_fs_devices(fs_devices);
 	return ERR_PTR(-ENOMEM);
 }
@@ -390,6 +475,7 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 
 	mutex_lock(&uuid_mutex);
 again:
+	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
 		if (device->in_fs_metadata)
 			continue;
@@ -409,6 +495,7 @@ again:
 		kfree(device->name);
 		kfree(device);
 	}
+	mutex_unlock(&fs_devices->device_list_mutex);
 
 	if (fs_devices->seed) {
 		fs_devices = fs_devices->seed;
@@ -529,6 +616,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		device->in_fs_metadata = 0;
 		device->mode = flags;
 
+		if (!blk_queue_nonrot(bdev_get_queue(bdev)))
+			fs_devices->rotating = 1;
+
 		fs_devices->open_devices++;
 		if (device->writeable) {
 			fs_devices->rw_devices++;
@@ -1056,12 +1146,14 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
 		device = NULL;
 		devices = &root->fs_info->fs_devices->devices;
+		mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 		list_for_each_entry(tmp, devices, dev_list) {
 			if (tmp->in_fs_metadata && !tmp->bdev) {
 				device = tmp;
 				break;
 			}
 		}
+		mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 		bdev = NULL;
 		bh = NULL;
 		disk_super = NULL;
@@ -1116,7 +1208,16 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 		goto error_brelse;
 
 	device->in_fs_metadata = 0;
+
+	/*
+	 * the device list mutex makes sure that we don't change
+	 * the device list while someone else is writing out all
+	 * the device supers.
+	 */
+	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 	list_del_init(&device->dev_list);
+	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+
 	device->fs_devices->num_devices--;
 
 	next_device = list_entry(root->fs_info->fs_devices->devices.next,
@@ -1210,6 +1311,7 @@ static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
 	seed_devices->opened = 1;
 	INIT_LIST_HEAD(&seed_devices->devices);
 	INIT_LIST_HEAD(&seed_devices->alloc_list);
+	mutex_init(&seed_devices->device_list_mutex);
 	list_splice_init(&fs_devices->devices, &seed_devices->devices);
 	list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
 	list_for_each_entry(device, &seed_devices->devices, dev_list) {
@@ -1335,6 +1437,10 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	mutex_lock(&root->fs_info->volume_mutex);
 
 	devices = &root->fs_info->fs_devices->devices;
+	/*
+	 * we have the volume lock, so we don't need the extra
+	 * device list mutex while reading the list here.
+	 */
 	list_for_each_entry(device, devices, dev_list) {
 		if (device->bdev == bdev) {
 			ret = -EEXIST;
@@ -1375,6 +1481,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	device->io_align = root->sectorsize;
 	device->sector_size = root->sectorsize;
 	device->total_bytes = i_size_read(bdev->bd_inode);
+	device->disk_total_bytes = device->total_bytes;
 	device->dev_root = root->fs_info->dev_root;
 	device->bdev = bdev;
 	device->in_fs_metadata = 1;
@@ -1388,6 +1495,12 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	}
 
 	device->fs_devices = root->fs_info->fs_devices;
+
+	/*
+	 * we don't want write_supers to jump in here with our device
+	 * half setup
+	 */
+	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 	list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
 	list_add(&device->dev_alloc_list,
 		 &root->fs_info->fs_devices->alloc_list);
@@ -1396,6 +1509,9 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	root->fs_info->fs_devices->rw_devices++;
 	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
 
+	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
+		root->fs_info->fs_devices->rotating = 1;
+
 	total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
 	btrfs_set_super_total_bytes(&root->fs_info->super_copy,
 				    total_bytes + device->total_bytes);
@@ -1403,6 +1519,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
 	btrfs_set_super_num_devices(&root->fs_info->super_copy,
 				    total_bytes + 1);
+	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 	if (seeding_dev) {
 		ret = init_first_rw_device(trans, root, device);
@@ -1478,7 +1595,7 @@ static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
 	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
 	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
 	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-	btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
+	btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
 	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
 	btrfs_mark_buffer_dirty(leaf);
 
@@ -1605,8 +1722,6 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 	int ret;
 	int i;
 
-	printk(KERN_INFO "btrfs relocating chunk %llu\n",
-	       (unsigned long long)chunk_offset);
 	root = root->fs_info->chunk_root;
 	extent_root = root->fs_info->extent_root;
 	em_tree = &root->fs_info->mapping_tree.map_tree;
@@ -1875,14 +1990,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	device->total_bytes = new_size;
 	if (device->writeable)
 		device->fs_devices->total_rw_bytes -= diff;
-	ret = btrfs_update_device(trans, device);
-	if (ret) {
-		unlock_chunks(root);
-		btrfs_end_transaction(trans, root);
-		goto done;
-	}
-	WARN_ON(diff > old_total);
-	btrfs_set_super_total_bytes(super_copy, old_total - diff);
 	unlock_chunks(root);
 	btrfs_end_transaction(trans, root);
 
@@ -1914,7 +2021,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 		length = btrfs_dev_extent_length(l, dev_extent);
 
 		if (key.offset + length <= new_size)
-			goto done;
+			break;
 
 		chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
 		chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
@@ -1927,6 +2034,26 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 			goto done;
 	}
 
+	/* Shrinking succeeded, else we would be at "done". */
+	trans = btrfs_start_transaction(root, 1);
+	if (!trans) {
+		ret = -ENOMEM;
+		goto done;
+	}
+	lock_chunks(root);
+
+	device->disk_total_bytes = new_size;
+	/* Now btrfs_update_device() will change the on-disk size. */
+	ret = btrfs_update_device(trans, device);
+	if (ret) {
+		unlock_chunks(root);
+		btrfs_end_transaction(trans, root);
+		goto done;
+	}
+	WARN_ON(diff > old_total);
+	btrfs_set_super_total_bytes(super_copy, old_total - diff);
+	unlock_chunks(root);
+	btrfs_end_transaction(trans, root);
 done:
 	btrfs_free_path(path);
 	return ret;
@@ -2497,7 +2624,7 @@ again:
 			max_errors = 1;
 		}
 	}
-	if (multi_ret && rw == WRITE &&
+	if (multi_ret && (rw & (1 << BIO_RW)) &&
 	    stripes_allocated < stripes_required) {
 		stripes_allocated = map->num_stripes;
 		free_extent_map(em);
@@ -2762,6 +2889,7 @@ static noinline int schedule_bio(struct btrfs_root *root,
 				 int rw, struct bio *bio)
 {
 	int should_queue = 1;
+	struct btrfs_pending_bios *pending_bios;
 
 	/* don't bother with additional async steps for reads, right now */
 	if (!(rw & (1 << BIO_RW))) {
@@ -2783,13 +2911,17 @@ static noinline int schedule_bio(struct btrfs_root *root,
 	bio->bi_rw |= rw;
 
 	spin_lock(&device->io_lock);
+	if (bio_sync(bio))
+		pending_bios = &device->pending_sync_bios;
+	else
+		pending_bios = &device->pending_bios;
 
-	if (device->pending_bio_tail)
-		device->pending_bio_tail->bi_next = bio;
+	if (pending_bios->tail)
+		pending_bios->tail->bi_next = bio;
 
-	device->pending_bio_tail = bio;
-	if (!device->pending_bios)
-		device->pending_bios = bio;
+	pending_bios->tail = bio;
+	if (!pending_bios->head)
+		pending_bios->head = bio;
 	if (device->running_pending)
 		should_queue = 0;
 
@@ -3006,7 +3138,8 @@ static int fill_device_from_item(struct extent_buffer *leaf,
 	unsigned long ptr;
 
 	device->devid = btrfs_device_id(leaf, dev_item);
-	device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+	device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+	device->total_bytes = device->disk_total_bytes;
 	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
 	device->type = btrfs_device_type(leaf, dev_item);
 	device->io_align = btrfs_device_io_align(leaf, dev_item);