mbox series

[v2,0/6] kaddr and pfn can be NULL to ->direct_access()

Message ID 20180725162849.8320-1-yehs2007@zoho.com (mailing list archive)
Headers show
Series kaddr and pfn can be NULL to ->direct_access() | expand

Message

Huaisheng Ye July 25, 2018, 4:28 p.m. UTC
From: Huaisheng Ye <yehs1@lenovo.com>

Changes since v1 [1]:
* Involve the previous patches for pfn can be NULL.
* Reword the patch descriptions according to Christian's comment.
* According to Ross's suggestion, replace local pointer dummy_addr
  with NULL within md/dm-writecache for direct_access.

[1]: https://lkml.org/lkml/2018/7/24/199

Some functions within fs/dax, dax/super and md/dm-writecache don't
need to get local pointer kaddr or variable pfn from direct_access.
Assigning NULL to kaddr or pfn to ->direct_access() is more
straightforward and simple than offering a useless local pointer or
variable.

So all ->direct_access() need to check the validity of pointer kaddr
and pfn for NULL assignment. If either of them is equal to NULL, that
is to say callers may have no need for kaddr or pfn, so this series of
patch are prepared for allowing them to pass in NULL instead of having
to pass in a local pointer or variable that they then just throw away.

Huaisheng Ye (6):
  libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access()
  s390, dcssblk: kaddr and pfn can be NULL to ->direct_access()
  tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access()
  dax/super: Do not request a pointer kaddr when not required
  md/dm-writecache: Don't request pointer dummy_addr when not required
  filesystem-dax: Do not request kaddr and pfn when not required

 drivers/dax/super.c             |  3 +--
 drivers/md/dm-writecache.c      |  3 +--
 drivers/nvdimm/pmem.c           |  7 +++++--
 drivers/s390/block/dcssblk.c    |  8 +++++---
 fs/dax.c                        | 13 ++++---------
 tools/testing/nvdimm/pmem-dax.c | 12 ++++++++----
 6 files changed, 24 insertions(+), 22 deletions(-)

Comments

Ross Zwisler July 25, 2018, 5:23 p.m. UTC | #1
On Thu, Jul 26, 2018 at 12:28:43AM +0800, Huaisheng Ye wrote:
> From: Huaisheng Ye <yehs1@lenovo.com>
> 
> Changes since v1 [1]:
> * Involve the previous patches for pfn can be NULL.
> * Reword the patch descriptions according to Christian's comment.
> * According to Ross's suggestion, replace local pointer dummy_addr
>   with NULL within md/dm-writecache for direct_access.
> 
> [1]: https://lkml.org/lkml/2018/7/24/199
> 
> Some functions within fs/dax, dax/super and md/dm-writecache don't
> need to get local pointer kaddr or variable pfn from direct_access.
> Assigning NULL to kaddr or pfn to ->direct_access() is more
> straightforward and simple than offering a useless local pointer or
> variable.
> 
> So all ->direct_access() need to check the validity of pointer kaddr
> and pfn for NULL assignment. If either of them is equal to NULL, that
> is to say callers may have no need for kaddr or pfn, so this series of
> patch are prepared for allowing them to pass in NULL instead of having
> to pass in a local pointer or variable that they then just throw away.

Looks good.  For the series:

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

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Dave Jiang July 25, 2018, 9:35 p.m. UTC | #2
Pretty straight forward series. Huaisheng, I can apply the whole series
to libnvdimm if we can get ack's from maintainer of dcssblk and
dm-writecache for the respective bits.

On 07/25/2018 09:28 AM, Huaisheng Ye wrote:
> From: Huaisheng Ye <yehs1@lenovo.com>
> 
> Changes since v1 [1]:
> * Involve the previous patches for pfn can be NULL.
> * Reword the patch descriptions according to Christian's comment.
> * According to Ross's suggestion, replace local pointer dummy_addr
>   with NULL within md/dm-writecache for direct_access.
> 
> [1]: https://lkml.org/lkml/2018/7/24/199
> 
> Some functions within fs/dax, dax/super and md/dm-writecache don't
> need to get local pointer kaddr or variable pfn from direct_access.
> Assigning NULL to kaddr or pfn to ->direct_access() is more
> straightforward and simple than offering a useless local pointer or
> variable.
> 
> So all ->direct_access() need to check the validity of pointer kaddr
> and pfn for NULL assignment. If either of them is equal to NULL, that
> is to say callers may have no need for kaddr or pfn, so this series of
> patch are prepared for allowing them to pass in NULL instead of having
> to pass in a local pointer or variable that they then just throw away.
> 
> Huaisheng Ye (6):
>   libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access()
>   s390, dcssblk: kaddr and pfn can be NULL to ->direct_access()
>   tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access()
>   dax/super: Do not request a pointer kaddr when not required
>   md/dm-writecache: Don't request pointer dummy_addr when not required
>   filesystem-dax: Do not request kaddr and pfn when not required
> 
>  drivers/dax/super.c             |  3 +--
>  drivers/md/dm-writecache.c      |  3 +--
>  drivers/nvdimm/pmem.c           |  7 +++++--
>  drivers/s390/block/dcssblk.c    |  8 +++++---
>  fs/dax.c                        | 13 ++++---------
>  tools/testing/nvdimm/pmem-dax.c | 12 ++++++++----
>  6 files changed, 24 insertions(+), 22 deletions(-)
> 

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Huaisheng HS1 Ye July 26, 2018, 1:29 a.m. UTC | #3
> From: Dave Jiang <dave.jiang@intel.com>
> Sent: Thursday, July 26, 2018 5:36 AM
> Subject: [External] Re: [PATCH v2 0/6] kaddr and pfn can be NULL to ->direct_access()
> 
> Pretty straight forward series. Huaisheng, I can apply the whole series
> to libnvdimm if we can get ack's from maintainer of dcssblk and
> dm-writecache for the respective bits.

Thanks Dave and Ross.

Hi Jan an Dan,

The previous patch series for NULL-pfn had got your Reviewed-by or Signed-off-by.
Now I have expanded them to local pointer kaddr, can I get your Reviewed-by for current
patch series? Your acks are very important to me.

Cheers,
Huaisheng Ye

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