Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Tom Talpey
On 5/17/2018 11:03 PM, Long Li wrote: Subject: Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA On 5/17/2018 8:22 PM, Long Li wrote: From: Long Li <lon...@microsoft.com> This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none)

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Tom Talpey
On 5/17/2018 11:03 PM, Long Li wrote: Subject: Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA On 5/17/2018 8:22 PM, Long Li wrote: From: Long Li This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none), CIFS copies I/O data from

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Christoph Hellwig
On Fri, May 18, 2018 at 06:03:09AM +, Long Li wrote: > I also want to point out that, I choose to implement .read_iter and > .write_iter from file_operations to implement direct I/O (CIFS is already > doing this for O_DIRECT, so following this code path will avoid a big mess > up). The

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Christoph Hellwig
On Fri, May 18, 2018 at 06:03:09AM +, Long Li wrote: > I also want to point out that, I choose to implement .read_iter and > .write_iter from file_operations to implement direct I/O (CIFS is already > doing this for O_DIRECT, so following this code path will avoid a big mess > up). The

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Christoph Hellwig
On Thu, May 17, 2018 at 07:10:04PM -0400, Tom Talpey wrote: > What's the security risk? This type of direct i/o behavior is not > uncommon, and can certainly be made safe, using the appropriate > memory registration and protection domains. Any risk needs to be > stated explicitly, and mitigation

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Christoph Hellwig
On Thu, May 17, 2018 at 07:10:04PM -0400, Tom Talpey wrote: > What's the security risk? This type of direct i/o behavior is not > uncommon, and can certainly be made safe, using the appropriate > memory registration and protection domains. Any risk needs to be > stated explicitly, and mitigation

RE: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Long Li
> Subject: Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for > RDMA > > On 5/17/2018 8:22 PM, Long Li wrote: > > From: Long Li <lon...@microsoft.com> > > > > This patchset implements direct user I/O through RDMA. > > > > In normal c

RE: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-18 Thread Long Li
> Subject: Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for > RDMA > > On 5/17/2018 8:22 PM, Long Li wrote: > > From: Long Li > > > > This patchset implements direct user I/O through RDMA. > > > > In normal code path (even with cache=none)

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-17 Thread Tom Talpey
On 5/17/2018 8:22 PM, Long Li wrote: From: Long Li This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none), CIFS copies I/O data from user-space to kernel-space for security reasons. With this patchset, a new mounting option is

Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-17 Thread Tom Talpey
On 5/17/2018 8:22 PM, Long Li wrote: From: Long Li This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none), CIFS copies I/O data from user-space to kernel-space for security reasons. With this patchset, a new mounting option is introduced to have

[RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-17 Thread Long Li
From: Long Li This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none), CIFS copies I/O data from user-space to kernel-space for security reasons. With this patchset, a new mounting option is introduced to have CIFS pin the

[RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

2018-05-17 Thread Long Li
From: Long Li This patchset implements direct user I/O through RDMA. In normal code path (even with cache=none), CIFS copies I/O data from user-space to kernel-space for security reasons. With this patchset, a new mounting option is introduced to have CIFS pin the user-space buffer into