Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On 11/12/18 8:14 AM, Dan Williams wrote:
On Mon, Nov 12, 2018 at 7:45 AM Keith Busch wrote:
On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
From: John Hubbard
An upcoming patch wants to be able to operate on each page that
get_user_pages has retrieved. In order to do that, it's best to
have a common exit point from the routine. Most of this has been
taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
pinning pages"), but there was one case remaining.
Also, there was still an unnecessary shadow declaration (with a
different type) of the "ret" variable, which this commit removes.
Cc: Keith Busch
Cc: Dan Williams
Cc: Kirill A. Shutemov
Cc: Dave Hansen
Signed-off-by: John Hubbard
---
mm/gup.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..55a41dee0340 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
if (!vma || start >= vma->vm_end) {
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(mm, start)) {
- int ret;
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, ,
pages ? [i] : NULL);
if (ret)
- return i ? : ret;
+ goto out;
ctx.page_mask = 0;
goto next_page;
}
This also fixes a potentially leaked dev_pagemap reference count if a
failure occurs when an iteration crosses a vma boundary. I don't think
it's normal to have different vma's on a users mapped zone device memory,
but good to fix anyway.
Does not sound abnormal to me, we should promote this as a fix for the
current cycle with an updated changelog.
Andrew, should I send this patch separately, or do you have what you
need already?
thanks,
--
John Hubbard
NVIDIA
Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On 11/12/18 8:14 AM, Dan Williams wrote:
On Mon, Nov 12, 2018 at 7:45 AM Keith Busch wrote:
On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
From: John Hubbard
An upcoming patch wants to be able to operate on each page that
get_user_pages has retrieved. In order to do that, it's best to
have a common exit point from the routine. Most of this has been
taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
pinning pages"), but there was one case remaining.
Also, there was still an unnecessary shadow declaration (with a
different type) of the "ret" variable, which this commit removes.
Cc: Keith Busch
Cc: Dan Williams
Cc: Kirill A. Shutemov
Cc: Dave Hansen
Signed-off-by: John Hubbard
---
mm/gup.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..55a41dee0340 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
if (!vma || start >= vma->vm_end) {
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(mm, start)) {
- int ret;
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, ,
pages ? [i] : NULL);
if (ret)
- return i ? : ret;
+ goto out;
ctx.page_mask = 0;
goto next_page;
}
This also fixes a potentially leaked dev_pagemap reference count if a
failure occurs when an iteration crosses a vma boundary. I don't think
it's normal to have different vma's on a users mapped zone device memory,
but good to fix anyway.
Does not sound abnormal to me, we should promote this as a fix for the
current cycle with an updated changelog.
Andrew, should I send this patch separately, or do you have what you
need already?
thanks,
--
John Hubbard
NVIDIA
Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On Mon, Nov 12, 2018 at 7:45 AM Keith Busch wrote:
>
> On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
> > From: John Hubbard
> >
> > An upcoming patch wants to be able to operate on each page that
> > get_user_pages has retrieved. In order to do that, it's best to
> > have a common exit point from the routine. Most of this has been
> > taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
> > pinning pages"), but there was one case remaining.
> >
> > Also, there was still an unnecessary shadow declaration (with a
> > different type) of the "ret" variable, which this commit removes.
> >
> > Cc: Keith Busch
> > Cc: Dan Williams
> > Cc: Kirill A. Shutemov
> > Cc: Dave Hansen
> > Signed-off-by: John Hubbard
> > ---
> > mm/gup.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/mm/gup.c b/mm/gup.c
> > index f76e77a2d34b..55a41dee0340 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
> > struct mm_struct *mm,
> > if (!vma || start >= vma->vm_end) {
> > vma = find_extend_vma(mm, start);
> > if (!vma && in_gate_area(mm, start)) {
> > - int ret;
> > ret = get_gate_page(mm, start & PAGE_MASK,
> > gup_flags, ,
> > pages ? [i] : NULL);
> > if (ret)
> > - return i ? : ret;
> > + goto out;
> > ctx.page_mask = 0;
> > goto next_page;
> > }
>
> This also fixes a potentially leaked dev_pagemap reference count if a
> failure occurs when an iteration crosses a vma boundary. I don't think
> it's normal to have different vma's on a users mapped zone device memory,
> but good to fix anyway.
Does not sound abnormal to me, we should promote this as a fix for the
current cycle with an updated changelog.
Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On Mon, Nov 12, 2018 at 7:45 AM Keith Busch wrote:
>
> On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
> > From: John Hubbard
> >
> > An upcoming patch wants to be able to operate on each page that
> > get_user_pages has retrieved. In order to do that, it's best to
> > have a common exit point from the routine. Most of this has been
> > taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
> > pinning pages"), but there was one case remaining.
> >
> > Also, there was still an unnecessary shadow declaration (with a
> > different type) of the "ret" variable, which this commit removes.
> >
> > Cc: Keith Busch
> > Cc: Dan Williams
> > Cc: Kirill A. Shutemov
> > Cc: Dave Hansen
> > Signed-off-by: John Hubbard
> > ---
> > mm/gup.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/mm/gup.c b/mm/gup.c
> > index f76e77a2d34b..55a41dee0340 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
> > struct mm_struct *mm,
> > if (!vma || start >= vma->vm_end) {
> > vma = find_extend_vma(mm, start);
> > if (!vma && in_gate_area(mm, start)) {
> > - int ret;
> > ret = get_gate_page(mm, start & PAGE_MASK,
> > gup_flags, ,
> > pages ? [i] : NULL);
> > if (ret)
> > - return i ? : ret;
> > + goto out;
> > ctx.page_mask = 0;
> > goto next_page;
> > }
>
> This also fixes a potentially leaked dev_pagemap reference count if a
> failure occurs when an iteration crosses a vma boundary. I don't think
> it's normal to have different vma's on a users mapped zone device memory,
> but good to fix anyway.
Does not sound abnormal to me, we should promote this as a fix for the
current cycle with an updated changelog.
Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
> From: John Hubbard
>
> An upcoming patch wants to be able to operate on each page that
> get_user_pages has retrieved. In order to do that, it's best to
> have a common exit point from the routine. Most of this has been
> taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
> pinning pages"), but there was one case remaining.
>
> Also, there was still an unnecessary shadow declaration (with a
> different type) of the "ret" variable, which this commit removes.
>
> Cc: Keith Busch
> Cc: Dan Williams
> Cc: Kirill A. Shutemov
> Cc: Dave Hansen
> Signed-off-by: John Hubbard
> ---
> mm/gup.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index f76e77a2d34b..55a41dee0340 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
> struct mm_struct *mm,
> if (!vma || start >= vma->vm_end) {
> vma = find_extend_vma(mm, start);
> if (!vma && in_gate_area(mm, start)) {
> - int ret;
> ret = get_gate_page(mm, start & PAGE_MASK,
> gup_flags, ,
> pages ? [i] : NULL);
> if (ret)
> - return i ? : ret;
> + goto out;
> ctx.page_mask = 0;
> goto next_page;
> }
This also fixes a potentially leaked dev_pagemap reference count if a
failure occurs when an iteration crosses a vma boundary. I don't think
it's normal to have different vma's on a users mapped zone device memory,
but good to fix anyway.
Reviewed-by: Keith Busch
Re: [PATCH v2 1/6] mm/gup: finish consolidating error handling
On Sat, Nov 10, 2018 at 12:50:36AM -0800, john.hubb...@gmail.com wrote:
> From: John Hubbard
>
> An upcoming patch wants to be able to operate on each page that
> get_user_pages has retrieved. In order to do that, it's best to
> have a common exit point from the routine. Most of this has been
> taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
> pinning pages"), but there was one case remaining.
>
> Also, there was still an unnecessary shadow declaration (with a
> different type) of the "ret" variable, which this commit removes.
>
> Cc: Keith Busch
> Cc: Dan Williams
> Cc: Kirill A. Shutemov
> Cc: Dave Hansen
> Signed-off-by: John Hubbard
> ---
> mm/gup.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index f76e77a2d34b..55a41dee0340 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
> struct mm_struct *mm,
> if (!vma || start >= vma->vm_end) {
> vma = find_extend_vma(mm, start);
> if (!vma && in_gate_area(mm, start)) {
> - int ret;
> ret = get_gate_page(mm, start & PAGE_MASK,
> gup_flags, ,
> pages ? [i] : NULL);
> if (ret)
> - return i ? : ret;
> + goto out;
> ctx.page_mask = 0;
> goto next_page;
> }
This also fixes a potentially leaked dev_pagemap reference count if a
failure occurs when an iteration crosses a vma boundary. I don't think
it's normal to have different vma's on a users mapped zone device memory,
but good to fix anyway.
Reviewed-by: Keith Busch
[PATCH v2 1/6] mm/gup: finish consolidating error handling
From: John Hubbard
An upcoming patch wants to be able to operate on each page that
get_user_pages has retrieved. In order to do that, it's best to
have a common exit point from the routine. Most of this has been
taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
pinning pages"), but there was one case remaining.
Also, there was still an unnecessary shadow declaration (with a
different type) of the "ret" variable, which this commit removes.
Cc: Keith Busch
Cc: Dan Williams
Cc: Kirill A. Shutemov
Cc: Dave Hansen
Signed-off-by: John Hubbard
---
mm/gup.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..55a41dee0340 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
if (!vma || start >= vma->vm_end) {
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(mm, start)) {
- int ret;
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, ,
pages ? [i] : NULL);
if (ret)
- return i ? : ret;
+ goto out;
ctx.page_mask = 0;
goto next_page;
}
--
2.19.1
[PATCH v2 1/6] mm/gup: finish consolidating error handling
From: John Hubbard
An upcoming patch wants to be able to operate on each page that
get_user_pages has retrieved. In order to do that, it's best to
have a common exit point from the routine. Most of this has been
taken care of by commit df06b37ffe5a4 ("mm/gup: cache dev_pagemap while
pinning pages"), but there was one case remaining.
Also, there was still an unnecessary shadow declaration (with a
different type) of the "ret" variable, which this commit removes.
Cc: Keith Busch
Cc: Dan Williams
Cc: Kirill A. Shutemov
Cc: Dave Hansen
Signed-off-by: John Hubbard
---
mm/gup.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index f76e77a2d34b..55a41dee0340 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -696,12 +696,11 @@ static long __get_user_pages(struct task_struct *tsk,
struct mm_struct *mm,
if (!vma || start >= vma->vm_end) {
vma = find_extend_vma(mm, start);
if (!vma && in_gate_area(mm, start)) {
- int ret;
ret = get_gate_page(mm, start & PAGE_MASK,
gup_flags, ,
pages ? [i] : NULL);
if (ret)
- return i ? : ret;
+ goto out;
ctx.page_mask = 0;
goto next_page;
}
--
2.19.1
