Re: [Qemu-devel] [RFC PATCH 18/18] nbd: Implement NBD_CMD_WRITE_ZEROES on client

2016-04-09 Thread Alex Bligh
On 10 Apr 2016, at 00:17, Eric Blake wrote: > No, the code is correct. In both functions, the logic is that if the > lower-level knows that the server respects FUA, then it clears the flag > before returning (flags is passed by reference, not value). Then at > this higher

Re: [Qemu-devel] [RFC PATCH 18/18] nbd: Implement NBD_CMD_WRITE_ZEROES on client

2016-04-09 Thread Eric Blake
On 04/09/2016 04:57 AM, Alex Bligh wrote: > > On 8 Apr 2016, at 23:05, Eric Blake wrote: > >> RFC because there is still discussion on the NBD list about >> adding an NBD_OPT_ to let the client suggest server defaults >> related to scanning for zeroes during NBD_CMD_WRITE,

Re: [Qemu-devel] [RFC PATCH 18/18] nbd: Implement NBD_CMD_WRITE_ZEROES on client

2016-04-09 Thread Pavel Borzenkov
On Sat, Apr 09, 2016 at 11:57:57AM +0100, Alex Bligh wrote: > > On 8 Apr 2016, at 23:05, Eric Blake wrote: > > > RFC because there is still discussion on the NBD list about > > adding an NBD_OPT_ to let the client suggest server defaults > > related to scanning for zeroes

Re: [Qemu-devel] [RFC PATCH 18/18] nbd: Implement NBD_CMD_WRITE_ZEROES on client

2016-04-09 Thread Alex Bligh
On 8 Apr 2016, at 23:05, Eric Blake wrote: > RFC because there is still discussion on the NBD list about > adding an NBD_OPT_ to let the client suggest server defaults > related to scanning for zeroes during NBD_CMD_WRITE, which may > tweak this patch. > > Upstream NBD

[Qemu-devel] [RFC PATCH 18/18] nbd: Implement NBD_CMD_WRITE_ZEROES on client

2016-04-08 Thread Eric Blake
RFC because there is still discussion on the NBD list about adding an NBD_OPT_ to let the client suggest server defaults related to scanning for zeroes during NBD_CMD_WRITE, which may tweak this patch. Upstream NBD protocol recently added the ability to efficiently write zeroes without having to