Re: [PATCH] btrfs: Add comments on locking of several device-related fields

[David Sterba <dsterba@suse.cz>]

On Thu, May 09, 2019 at 05:12:16PM +0300, Nikolay Borisov wrote:
> 
> 
> On 9.05.19 г. 16:55 ч., David Sterba wrote:
> > On Tue, May 07, 2019 at 05:24:28PM +0300, Nikolay Borisov wrote:
> >> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> >> ---
> >>  fs/btrfs/volumes.h | 11 ++++++++---
> >>  1 file changed, 8 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
> >> index 3b97e8092ba7..514799362244 100644
> >> --- a/fs/btrfs/volumes.h
> >> +++ b/fs/btrfs/volumes.h
> >> @@ -52,8 +52,8 @@ struct btrfs_io_geometry {
> >>  #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 */
> > 
> > Please update the documentation in the comment 'Device locking' in
> > volumes.c
> 
> Right the only thing that is missing from the Device Locking comment is
> the mention of post_commit_list. However, dev_list and dev_alloc_list
> are essentially "the other side" of btrfs_fs_devices::alloc_list  hence
> I've added them as inline comments. I think it makes more sense to those
> small comments next to the variables at least as a remainder.

Ok.