[PATCH] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[PATCH] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov]

Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.

Signed-off-by: Denis Efremov <efremov@linux.com>
---

I'm not sure about TODO comment, through.

 fs/udf/super.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1c42f544096d..c7cd15219b7c 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1013,10 +1013,7 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
 	size = sizeof(struct udf_bitmap) +
 		(sizeof(struct buffer_head *) * nr_groups);
 
-	if (size <= PAGE_SIZE)
-		bitmap = kzalloc(size, GFP_KERNEL);
-	else
-		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
+	bitmap = kvzalloc(size, GFP_KERNEL);
 
 	if (!bitmap)
 		return NULL;
-- 
2.26.2

Re: [PATCH] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov]

> @@ -1013,10 +1013,7 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
>  	size = sizeof(struct udf_bitmap) +
>  		(sizeof(struct buffer_head *) * nr_groups);

I missed that this size is a good place to use struct_size for
overflow checking. I will send v2 instead.

Re: [PATCH] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Joe Perches]

On Thu, 2020-08-27 at 18:28 +0300, Denis Efremov wrote:
> > @@ -1013,10 +1013,7 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
> >  	size = sizeof(struct udf_bitmap) +
> >  		(sizeof(struct buffer_head *) * nr_groups);
> 
> I missed that this size is a good place to use struct_size for
> overflow checking. I will send v2 instead.

And you could cuddle the

	if (!bitmap)
		return NULL;

by removing the blank line between the alloc and test.

[PATCH v2] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov]

Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
Size computation wrapped in struct_size() macro to prevent potential
integer overflows.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 fs/udf/super.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1c42f544096d..bdf51bea54f3 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1010,14 +1010,9 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
 	int size;
 
 	nr_groups = udf_compute_nr_groups(sb, index);
-	size = sizeof(struct udf_bitmap) +
-		(sizeof(struct buffer_head *) * nr_groups);
-
-	if (size <= PAGE_SIZE)
-		bitmap = kzalloc(size, GFP_KERNEL);
-	else
-		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
+	size = struct_size(bitmap, s_block_bitmap, nr_groups);
 
+	bitmap = kvzalloc(size, GFP_KERNEL);
 	if (!bitmap)
 		return NULL;
 
-- 
2.26.2

Re: [PATCH v2] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov]

On 8/28/20 1:09 AM, Gustavo A. R. Silva wrote:
> 
> 
> On 8/27/20 16:25, Denis Efremov wrote:
>> Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
>> Size computation wrapped in struct_size() macro to prevent potential
>> integer overflows.
>>
>> Signed-off-by: Denis Efremov <efremov@linux.com>
>> ---
> 
> Please, comment here what changed in v2, vn... e.g.:
> 
> Changes in v2:
>  - Use struct_size() helper.
>

Ah, thanks. I added this initially and accidentally regenerated the patch
file with format-patch.
 
> 
> Why not this:
> 
> bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
> 		  GFP_KERNEL);
> 
> and you can also get rid of _size_ entirely.
> 

My bad, I missed that only nr_groups is used down the code.

Thanks, I will resend it as v3.

Denis

Re: [PATCH v2] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Gustavo A. R. Silva]

On 8/27/20 16:25, Denis Efremov wrote:
> Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
> Size computation wrapped in struct_size() macro to prevent potential
> integer overflows.
> 
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---

Please, comment here what changed in v2, vn... e.g.:

Changes in v2:
 - Use struct_size() helper.


>  fs/udf/super.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/udf/super.c b/fs/udf/super.c
> index 1c42f544096d..bdf51bea54f3 100644
> --- a/fs/udf/super.c
> +++ b/fs/udf/super.c
> @@ -1010,14 +1010,9 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
>  	int size;
>  
>  	nr_groups = udf_compute_nr_groups(sb, index);
> -	size = sizeof(struct udf_bitmap) +
> -		(sizeof(struct buffer_head *) * nr_groups);
> -
> -	if (size <= PAGE_SIZE)
> -		bitmap = kzalloc(size, GFP_KERNEL);
> -	else
> -		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
> +	size = struct_size(bitmap, s_block_bitmap, nr_groups);
>  
> +	bitmap = kvzalloc(size, GFP_KERNEL);

Why not this:

bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
		  GFP_KERNEL);

and you can also get rid of _size_ entirely.

Thanks
--
Gustavo

>  	if (!bitmap)
>  		return NULL;
>  
> 

[PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Denis Efremov]

Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
Size computation wrapped in struct_size() macro to prevent potential
integer overflows.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
Changes in v2:
 - size computation wrapped in struct_size()
Changes in v3:
 - int size dropped

 fs/udf/super.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1c42f544096d..d9eabbe368ff 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1006,18 +1006,10 @@ int udf_compute_nr_groups(struct super_block *sb, u32 partition)
 static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
 {
 	struct udf_bitmap *bitmap;
-	int nr_groups;
-	int size;
-
-	nr_groups = udf_compute_nr_groups(sb, index);
-	size = sizeof(struct udf_bitmap) +
-		(sizeof(struct buffer_head *) * nr_groups);
-
-	if (size <= PAGE_SIZE)
-		bitmap = kzalloc(size, GFP_KERNEL);
-	else
-		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
+	int nr_groups = udf_compute_nr_groups(sb, index);
 
+	bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
+			  GFP_KERNEL);
 	if (!bitmap)
 		return NULL;
 
-- 
2.26.2

Re: [PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Gustavo A. R. Silva]

On 8/27/20 17:16, Denis Efremov wrote:
> Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
> Size computation wrapped in struct_size() macro to prevent potential
> integer overflows.
> 
> Signed-off-by: Denis Efremov <efremov@linux.com>

Looks good. :)

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
> Changes in v2:
>  - size computation wrapped in struct_size()
> Changes in v3:
>  - int size dropped
> 
>  fs/udf/super.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/udf/super.c b/fs/udf/super.c
> index 1c42f544096d..d9eabbe368ff 100644
> --- a/fs/udf/super.c
> +++ b/fs/udf/super.c
> @@ -1006,18 +1006,10 @@ int udf_compute_nr_groups(struct super_block *sb, u32 partition)
>  static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
>  {
>  	struct udf_bitmap *bitmap;
> -	int nr_groups;
> -	int size;
> -
> -	nr_groups = udf_compute_nr_groups(sb, index);
> -	size = sizeof(struct udf_bitmap) +
> -		(sizeof(struct buffer_head *) * nr_groups);
> -
> -	if (size <= PAGE_SIZE)
> -		bitmap = kzalloc(size, GFP_KERNEL);
> -	else
> -		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
> +	int nr_groups = udf_compute_nr_groups(sb, index);
>  
> +	bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
> +			  GFP_KERNEL);
>  	if (!bitmap)
>  		return NULL;
>  
> 

Re: [PATCH v3] udf: Use kvzalloc() in udf_sb_alloc_bitmap()

[Jan Kara]

On Thu 27-08-20 17:29:25, Gustavo A. R. Silva wrote:
> 
> 
> On 8/27/20 17:16, Denis Efremov wrote:
> > Use kvzalloc() in udf_sb_alloc_bitmap() instead of open-coding it.
> > Size computation wrapped in struct_size() macro to prevent potential
> > integer overflows.
> > 
> > Signed-off-by: Denis Efremov <efremov@linux.com>
> 
> Looks good. :)
> 
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thank you both. I've added the patch to my tree.

								Honza

> 
> Thanks
> --
> Gustavo
> 
> > ---
> > Changes in v2:
> >  - size computation wrapped in struct_size()
> > Changes in v3:
> >  - int size dropped
> > 
> >  fs/udf/super.c | 14 +++-----------
> >  1 file changed, 3 insertions(+), 11 deletions(-)
> > 
> > diff --git a/fs/udf/super.c b/fs/udf/super.c
> > index 1c42f544096d..d9eabbe368ff 100644
> > --- a/fs/udf/super.c
> > +++ b/fs/udf/super.c
> > @@ -1006,18 +1006,10 @@ int udf_compute_nr_groups(struct super_block *sb, u32 partition)
> >  static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
> >  {
> >  	struct udf_bitmap *bitmap;
> > -	int nr_groups;
> > -	int size;
> > -
> > -	nr_groups = udf_compute_nr_groups(sb, index);
> > -	size = sizeof(struct udf_bitmap) +
> > -		(sizeof(struct buffer_head *) * nr_groups);
> > -
> > -	if (size <= PAGE_SIZE)
> > -		bitmap = kzalloc(size, GFP_KERNEL);
> > -	else
> > -		bitmap = vzalloc(size); /* TODO: get rid of vzalloc */
> > +	int nr_groups = udf_compute_nr_groups(sb, index);
> >  
> > +	bitmap = kvzalloc(struct_size(bitmap, s_block_bitmap, nr_groups),
> > +			  GFP_KERNEL);
> >  	if (!bitmap)
> >  		return NULL;
> >  
> > 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR