Commit 0b6f5d40 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Add comments on locking of several device-related fields 



Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent bd80d94e

fs/btrfs/volumes.c

+3 −1
Original line number Diff line number Diff line
@@ -239,7 +239,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, 
 * chunk_mutex

 * -----------

 * protects chunks, adding or removing during allocation, trim or when a new

 * device is added/removed

 * device is added/removed. Additionally it also protects post_commit_list of

 * individual devices, since they can be added to the transaction's

 * post_commit_list only with chunk_mutex held.

 *

 * cleaner_mutex

 * -------------

fs/btrfs/volumes.h

+8 −3
Original line number Diff line number Diff line
@@ -43,8 +43,8 @@ struct btrfs_pending_bios { 
#define BTRFS_DEV_STATE_FLUSH_SENT	(4)



struct btrfs_device {

	struct list_head dev_list;

	struct list_head dev_alloc_list;

	struct list_head dev_list; /* device_list_mutex */

	struct list_head dev_alloc_list; /* chunk mutex */

	struct list_head post_commit_list; /* chunk mutex */

	struct btrfs_fs_devices *fs_devices;

	struct btrfs_fs_info *fs_info;
@@ -229,9 +229,14 @@ struct btrfs_fs_devices { 
	 * this mutex lock.

	 */

	struct mutex device_list_mutex;



	/* List of all devices, protected by device_list_mutex */

	struct list_head devices;



	/* devices not currently being allocated */

	/*

	 * Devices which can satisfy space allocation. Protected by

	 * chunk_mutex

	 */

	struct list_head alloc_list;



	struct btrfs_fs_devices *seed;