Re: [PATCHv2 1/6] blk-sysfs: remove q->sysfs_lock for attributes which don't need it

[Christoph Hellwig <hch@lst.de>]

On Tue, Feb 18, 2025 at 01:58:54PM +0530, Nilay Shroff wrote:
> There're few sysfs attributes in block layer which don't really need
> acquiring q->sysfs_lock while accessing it. The reason being, writing
> a value to such attributes are either atomic or could be easily
> protected using WRITE_ONCE()/READ_ONCE(). Moreover, sysfs attributes
> are inherently protected with sysfs/kernfs internal locking.
> 
> So this change help segregate all existing sysfs attributes for which 
> we could avoid acquiring q->sysfs_lock. We group all such attributes,
> which don't require any sorts of locking, using macro QUEUE_RO_ENTRY_
> NOLOCK() or QUEUE_RW_ENTRY_NOLOCK(). The newly introduced show/store 
> method (show_nolock/store_nolock) is assigned to attributes using these 
> new macros. The show_nolock/store_nolock run without holding q->sysfs_
> lock.

Can you add the analys why they don't need sysfs_lock to this commit
message please?

With that:

Reviewed-by: Christoph Hellwig <hch@lst.de>