Btrfs: fix wrong disk size when writing super blocks

total_size will be changed when resizing a device, and disk_total_size
will be changed if resizing is successful. Meanwhile, the on-disk super
blocks of the previous transaction might not be updated. Considering
the consistency of the metadata in the previous transaction, We should
use the size in the previous transaction to check if the super block is
beyond the boundary of the device. Fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 39 insertions, 1 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1646659f2800..7b5c04259a6e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -74,6 +74,7 @@ static struct btrfs_fs_devices *__alloc_fs_devices(void)
 	mutex_init(&fs_devs->device_list_mutex);
 
 	INIT_LIST_HEAD(&fs_devs->devices);
+	INIT_LIST_HEAD(&fs_devs->resized_devices);
 	INIT_LIST_HEAD(&fs_devs->alloc_list);
 	INIT_LIST_HEAD(&fs_devs->list);
 
@@ -154,6 +155,7 @@ static struct btrfs_device *__alloc_device(void)
 
 	INIT_LIST_HEAD(&dev->dev_list);
 	INIT_LIST_HEAD(&dev->dev_alloc_list);
+	INIT_LIST_HEAD(&dev->resized_list);
 
 	spin_lock_init(&dev->io_lock);
 
@@ -2168,6 +2170,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	device->sector_size = root->sectorsize;
 	device->total_bytes = i_size_read(bdev->bd_inode);
 	device->disk_total_bytes = device->total_bytes;
+	device->commit_total_bytes = device->total_bytes;
 	device->dev_root = root->fs_info->dev_root;
 	device->bdev = bdev;
 	device->in_fs_metadata = 1;
@@ -2364,6 +2367,8 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
 	device->sector_size = root->sectorsize;
 	device->total_bytes = srcdev->total_bytes;
 	device->disk_total_bytes = srcdev->disk_total_bytes;
+	ASSERT(list_empty(&srcdev->resized_list));
+	device->commit_total_bytes = srcdev->commit_total_bytes;
 	device->bytes_used = srcdev->bytes_used;
 	device->dev_root = fs_info->dev_root;
 	device->bdev = bdev;
@@ -2448,6 +2453,7 @@ static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_super_block *super_copy =
 		device->dev_root->fs_info->super_copy;
+	struct btrfs_fs_devices *fs_devices;
 	u64 old_total = btrfs_super_total_bytes(super_copy);
 	u64 diff = new_size - device->total_bytes;
 
@@ -2457,12 +2463,17 @@ static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
 	    device->is_tgtdev_for_dev_replace)
 		return -EINVAL;
 
+	fs_devices = device->dev_root->fs_info->fs_devices;
+
 	btrfs_set_super_total_bytes(super_copy, old_total + diff);
 	device->fs_devices->total_rw_bytes += diff;
 
 	device->total_bytes = new_size;
 	device->disk_total_bytes = new_size;
 	btrfs_clear_space_info_full(device->dev_root->fs_info);
+	if (list_empty(&device->resized_list))
+		list_add_tail(&device->resized_list,
+			      &fs_devices->resized_devices);
 
 	return btrfs_update_device(trans, device);
 }
@@ -4011,8 +4022,11 @@ again:
 	}
 
 	lock_chunks(root);
-
 	device->disk_total_bytes = new_size;
+	if (list_empty(&device->resized_list))
+		list_add_tail(&device->resized_list,
+			      &root->fs_info->fs_devices->resized_devices);
+
 	/* Now btrfs_update_device() will change the on-disk size. */
 	ret = btrfs_update_device(trans, device);
 	if (ret) {
@@ -5993,6 +6007,7 @@ static void fill_device_from_item(struct extent_buffer *leaf,
 	device->devid = btrfs_device_id(leaf, dev_item);
 	device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
 	device->total_bytes = device->disk_total_bytes;
+	device->commit_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);
@@ -6520,3 +6535,26 @@ int btrfs_scratch_superblock(struct btrfs_device *device)
 
 	return 0;
 }
+
+/*
+ * Update the size of all devices, which is used for writing out the
+ * super blocks.
+ */
+void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	struct btrfs_device *curr, *next;
+
+	if (list_empty(&fs_devices->resized_devices))
+		return;
+
+	mutex_lock(&fs_devices->device_list_mutex);
+	lock_chunks(fs_info->dev_root);
+	list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
+				 resized_list) {
+		list_del_init(&curr->resized_list);
+		curr->commit_total_bytes = curr->disk_total_bytes;
+	}
+	unlock_chunks(fs_info->dev_root);
+	mutex_unlock(&fs_devices->device_list_mutex);
+}