>Subject: Re: [PATCH] cifs: Remove locking in smb2_verify_signature() when >calculating SMB2/SMB3 signature on receiving packets > >longli@xxxxxxxxxxxxxxxxx writes: >> On the sending and receiving paths, CIFS uses the same cypto data >> structures to calculate SMB2/SMB3 packet signatures. A lock on the >> receiving path is necessary to control shared access to crypto data >> structures. This lock degrades performance because it races with the >sending path. >> >> Define separate crypto data structures for sending and receiving paths >> and remove this lock. > >Something I've often wondered: why do we keep crypto state in the server >structure instead of creating it as needed in the caller stack (thus avoiding the >need for locks). AFAIK there's no state that need to be kept between >signing/encrypting calls beside the access to keys. Is it that expensive to >create/release? My guess is that crypto_alloc_shash() is a heavy call? > >Cheers, >-- >Aurélien Aptel / SUSE Labs Samba Team >GPG: 1839 CB5F 9F5B FB9B AA97 8C99 03C8 A49B 521B D5D3 SUSE Software >Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE >GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)
