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Commit 174ba509 authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: use the device_list_mutex during write_dev_supers 



write_dev_supers was changed to use RCU to protect the list of
devices, but it was then sleeping while it actually wrote the supers.
This fixes it to just use the mutex, since we really don't any
concurrency in write_dev_supers anyway.

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent a47d6b70

fs/btrfs/disk-io.c

+2 −2
Original line number Diff line number Diff line
@@ -2310,7 +2310,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors) 
	sb = &root->fs_info->super_for_commit;

	dev_item = &sb->dev_item;



	rcu_read_lock();

	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);

	head = &root->fs_info->fs_devices->devices;

	list_for_each_entry_rcu(dev, head, dev_list) {

		if (!dev->bdev) {
@@ -2355,7 +2355,7 @@ int write_all_supers(struct btrfs_root *root, int max_mirrors) 
		if (ret)

			total_errors++;

	}

	rcu_read_unlock();

	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);

	if (total_errors > max_errors) {

		printk(KERN_ERR "btrfs: %d errors while writing supers\n",

		       total_errors);