* [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
@ 2017-12-09 7:09 ` Christophe JAILLET
0 siblings, 0 replies; 7+ messages in thread
From: Christophe JAILLET @ 2017-12-09 7:09 UTC (permalink / raw)
To: dan.j.williams, akpm, borntraeger, mhocko, dsterba, gregkh
Cc: linux-mm, linux-kernel, kernel-janitors, Christophe JAILLET
A semaphore is acquired before this check, so we must release it before
leaving.
Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
-- Untested --
The wording of the commit entry and log description could be improved
but I didn't find something better.
---
mm/frame_vector.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 297c7238f7d4..e0c5e659fa82 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
* get_user_pages_longterm() and disallow it for filesystem-dax
* mappings.
*/
- if (vma_is_fsdax(vma))
+ if (vma_is_fsdax(vma)) {
+ up_read(&mm->mmap_sem);
return -EOPNOTSUPP;
+ }
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
vec->got_ref = true;
--
2.14.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
@ 2017-12-09 7:09 ` Christophe JAILLET
0 siblings, 0 replies; 7+ messages in thread
From: Christophe JAILLET @ 2017-12-09 7:09 UTC (permalink / raw)
To: dan.j.williams, akpm, borntraeger, mhocko, dsterba, gregkh
Cc: linux-mm, linux-kernel, kernel-janitors, Christophe JAILLET
A semaphore is acquired before this check, so we must release it before
leaving.
Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
-- Untested --
The wording of the commit entry and log description could be improved
but I didn't find something better.
---
mm/frame_vector.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 297c7238f7d4..e0c5e659fa82 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
* get_user_pages_longterm() and disallow it for filesystem-dax
* mappings.
*/
- if (vma_is_fsdax(vma))
+ if (vma_is_fsdax(vma)) {
+ up_read(&mm->mmap_sem);
return -EOPNOTSUPP;
+ }
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
vec->got_ref = true;
--
2.14.1
--
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^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
@ 2017-12-09 7:09 ` Christophe JAILLET
0 siblings, 0 replies; 7+ messages in thread
From: Christophe JAILLET @ 2017-12-09 7:09 UTC (permalink / raw)
To: dan.j.williams, akpm, borntraeger, mhocko, dsterba, gregkh
Cc: linux-mm, linux-kernel, kernel-janitors, Christophe JAILLET
A semaphore is acquired before this check, so we must release it before
leaving.
Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
-- Untested --
The wording of the commit entry and log description could be improved
but I didn't find something better.
---
mm/frame_vector.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 297c7238f7d4..e0c5e659fa82 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
* get_user_pages_longterm() and disallow it for filesystem-dax
* mappings.
*/
- if (vma_is_fsdax(vma))
+ if (vma_is_fsdax(vma)) {
+ up_read(&mm->mmap_sem);
return -EOPNOTSUPP;
+ }
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
vec->got_ref = true;
--
2.14.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
2017-12-09 7:09 ` Christophe JAILLET
(?)
@ 2017-12-10 9:45 ` Michal Hocko
-1 siblings, 0 replies; 7+ messages in thread
From: Michal Hocko @ 2017-12-10 9:45 UTC (permalink / raw)
To: Christophe JAILLET
Cc: dan.j.williams, akpm, borntraeger, dsterba, gregkh, linux-mm,
linux-kernel, kernel-janitors
On Sat 09-12-17 08:09:41, Christophe JAILLET wrote:
> A semaphore is acquired before this check, so we must release it before
> leaving.
>
> Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> -- Untested --
>
> The wording of the commit entry and log description could be improved
> but I didn't find something better.
The changelog is ok imo.
> ---
> mm/frame_vector.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/frame_vector.c b/mm/frame_vector.c
> index 297c7238f7d4..e0c5e659fa82 100644
> --- a/mm/frame_vector.c
> +++ b/mm/frame_vector.c
> @@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
> * get_user_pages_longterm() and disallow it for filesystem-dax
> * mappings.
> */
> - if (vma_is_fsdax(vma))
> + if (vma_is_fsdax(vma)) {
> + up_read(&mm->mmap_sem);
> return -EOPNOTSUPP;
> + }
Is there any reason to do a different error handling than other error
paths? Namely not going without goto out?
>
> if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
> vec->got_ref = true;
> --
> 2.14.1
>
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
@ 2017-12-10 9:45 ` Michal Hocko
0 siblings, 0 replies; 7+ messages in thread
From: Michal Hocko @ 2017-12-10 9:45 UTC (permalink / raw)
To: Christophe JAILLET
Cc: dan.j.williams, akpm, borntraeger, dsterba, gregkh, linux-mm,
linux-kernel, kernel-janitors
On Sat 09-12-17 08:09:41, Christophe JAILLET wrote:
> A semaphore is acquired before this check, so we must release it before
> leaving.
>
> Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> -- Untested --
>
> The wording of the commit entry and log description could be improved
> but I didn't find something better.
The changelog is ok imo.
> ---
> mm/frame_vector.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/frame_vector.c b/mm/frame_vector.c
> index 297c7238f7d4..e0c5e659fa82 100644
> --- a/mm/frame_vector.c
> +++ b/mm/frame_vector.c
> @@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
> * get_user_pages_longterm() and disallow it for filesystem-dax
> * mappings.
> */
> - if (vma_is_fsdax(vma))
> + if (vma_is_fsdax(vma)) {
> + up_read(&mm->mmap_sem);
> return -EOPNOTSUPP;
> + }
Is there any reason to do a different error handling than other error
paths? Namely not going without goto out?
>
> if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
> vec->got_ref = true;
> --
> 2.14.1
>
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
@ 2017-12-10 9:45 ` Michal Hocko
0 siblings, 0 replies; 7+ messages in thread
From: Michal Hocko @ 2017-12-10 9:45 UTC (permalink / raw)
To: Christophe JAILLET
Cc: dan.j.williams, akpm, borntraeger, dsterba, gregkh, linux-mm,
linux-kernel, kernel-janitors
On Sat 09-12-17 08:09:41, Christophe JAILLET wrote:
> A semaphore is acquired before this check, so we must release it before
> leaving.
>
> Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> -- Untested --
>
> The wording of the commit entry and log description could be improved
> but I didn't find something better.
The changelog is ok imo.
> ---
> mm/frame_vector.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/frame_vector.c b/mm/frame_vector.c
> index 297c7238f7d4..e0c5e659fa82 100644
> --- a/mm/frame_vector.c
> +++ b/mm/frame_vector.c
> @@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
> * get_user_pages_longterm() and disallow it for filesystem-dax
> * mappings.
> */
> - if (vma_is_fsdax(vma))
> + if (vma_is_fsdax(vma)) {
> + up_read(&mm->mmap_sem);
> return -EOPNOTSUPP;
> + }
Is there any reason to do a different error handling than other error
paths? Namely not going without goto out?
>
> if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
> vec->got_ref = true;
> --
> 2.14.1
>
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] mm: Release a semaphore in 'get_vaddr_frames()'
2017-12-10 9:45 ` Michal Hocko
(?)
(?)
@ 2017-12-11 7:28 ` Christophe JAILLET
-1 siblings, 0 replies; 7+ messages in thread
From: Christophe JAILLET @ 2017-12-11 7:28 UTC (permalink / raw)
To: linux-kernel; +Cc: linux-mm, kernel-janitors
Le 10/12/2017 à 10:45, Michal Hocko a écrit :
> On Sat 09-12-17 08:09:41, Christophe JAILLET wrote:
>> A semaphore is acquired before this check, so we must release it before
>> leaving.
>>
>> Fixes: b7f0554a56f2 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>> -- Untested --
>>
>> The wording of the commit entry and log description could be improved
>> but I didn't find something better.
> The changelog is ok imo.
>
>> ---
>> mm/frame_vector.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/frame_vector.c b/mm/frame_vector.c
>> index 297c7238f7d4..e0c5e659fa82 100644
>> --- a/mm/frame_vector.c
>> +++ b/mm/frame_vector.c
>> @@ -62,8 +62,10 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
>> * get_user_pages_longterm() and disallow it for filesystem-dax
>> * mappings.
>> */
>> - if (vma_is_fsdax(vma))
>> + if (vma_is_fsdax(vma)) {
>> + up_read(&mm->mmap_sem);
>> return -EOPNOTSUPP;
>> + }
> Is there any reason to do a different error handling than other error
> paths? Namely not going without goto out?
You are right, I misread the code after out:.
I thought it would override the returned value, but I was wrong.
'goto out' is definitively better, IMHO. I'll propose a v2.
CJ
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2017-12-11 7:29 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-12-09 7:09 [PATCH] mm: Release a semaphore in 'get_vaddr_frames()' Christophe JAILLET
2017-12-09 7:09 ` Christophe JAILLET
2017-12-09 7:09 ` Christophe JAILLET
2017-12-10 9:45 ` Michal Hocko
2017-12-10 9:45 ` Michal Hocko
2017-12-10 9:45 ` Michal Hocko
2017-12-11 7:28 ` Christophe JAILLET
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