[PATCH RFC 11/13] md/bitmap: simplify the printing with '%pD' specifier

[PATCH RFC 11/13] md/bitmap: simplify the printing with '%pD' specifier

[Jia He]

After the behavior of '%pD' is changed to print the full path of file,
the log printing can be simplified.

Given the space with proper length would be allocated in vprintk_store(),
it is worthy of dropping kmalloc()/kfree() to avoid additional space
allocation. The error case is well handled in d_path_unsafe(), the error
string would be copied in '%pD' buffer, no need to additionally handle
IS_ERR().

Cc: Song Liu <song@kernel.org>
Cc: linux-raid@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jia He <justin.he@arm.com>
---
 drivers/md/md-bitmap.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index e29c6298ef5c..a82f1c2ef83c 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -862,21 +862,12 @@ static void md_bitmap_file_unmap(struct bitmap_storage *store)
  */
 static void md_bitmap_file_kick(struct bitmap *bitmap)
 {
-	char *path, *ptr = NULL;
-
 	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
 		md_bitmap_update_sb(bitmap);
 
 		if (bitmap->storage.file) {
-			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
-			if (path)
-				ptr = file_path(bitmap->storage.file,
-					     path, PAGE_SIZE);
-
-			pr_warn("%s: kicking failed bitmap file %s from array!\n",
-				bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
-
-			kfree(path);
+			pr_warn("%s: kicking failed bitmap file %pD from array!\n",
+				bmname(bitmap), bitmap->storage.file);
 		} else
 			pr_warn("%s: disabling internal bitmap due to errors\n",
 				bmname(bitmap));
-- 
2.17.1

Re: [PATCH RFC 11/13] md/bitmap: simplify the printing with '%pD' specifier

[Guoqing Jiang]

On 7/15/21 11:15 AM, Jia He wrote:
> After the behavior of '%pD' is changed to print the full path of file,
> the log printing can be simplified.
>
> Given the space with proper length would be allocated in vprintk_store(),
> it is worthy of dropping kmalloc()/kfree() to avoid additional space
> allocation. The error case is well handled in d_path_unsafe(), the error
> string would be copied in '%pD' buffer, no need to additionally handle
> IS_ERR().
>
> Cc: Song Liu <song@kernel.org>
> Cc: linux-raid@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Jia He <justin.he@arm.com>
> ---
>   drivers/md/md-bitmap.c | 13 ++-----------
>   1 file changed, 2 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
> index e29c6298ef5c..a82f1c2ef83c 100644
> --- a/drivers/md/md-bitmap.c
> +++ b/drivers/md/md-bitmap.c
> @@ -862,21 +862,12 @@ static void md_bitmap_file_unmap(struct bitmap_storage *store)
>    */
>   static void md_bitmap_file_kick(struct bitmap *bitmap)
>   {
> -	char *path, *ptr = NULL;
> -
>   	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
>   		md_bitmap_update_sb(bitmap);
>   
>   		if (bitmap->storage.file) {
> -			path = kmalloc(PAGE_SIZE, GFP_KERNEL);
> -			if (path)
> -				ptr = file_path(bitmap->storage.file,
> -					     path, PAGE_SIZE);
> -
> -			pr_warn("%s: kicking failed bitmap file %s from array!\n",
> -				bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
> -
> -			kfree(path);
> +			pr_warn("%s: kicking failed bitmap file %pD from array!\n",
> +				bmname(bitmap), bitmap->storage.file);
>   		} else
>   			pr_warn("%s: disabling internal bitmap due to errors\n",
>   				bmname(bitmap));

Looks good,  Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>

Thanks,
Guoqing

Re: [PATCH RFC 11/13] md/bitmap: simplify the printing with '%pD' specifier

[Song Liu]

On Fri, Jul 16, 2021 at 2:41 AM Guoqing Jiang <guoqing.jiang@linux.dev> wrote:
>
>
>
> On 7/15/21 11:15 AM, Jia He wrote:
> > After the behavior of '%pD' is changed to print the full path of file,
> > the log printing can be simplified.
> >
> > Given the space with proper length would be allocated in vprintk_store(),
> > it is worthy of dropping kmalloc()/kfree() to avoid additional space
> > allocation. The error case is well handled in d_path_unsafe(), the error
> > string would be copied in '%pD' buffer, no need to additionally handle
> > IS_ERR().
> >
> > Cc: Song Liu <song@kernel.org>
> > Cc: linux-raid@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Signed-off-by: Jia He <justin.he@arm.com>
> > ---
> >   drivers/md/md-bitmap.c | 13 ++-----------
> >   1 file changed, 2 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
> > index e29c6298ef5c..a82f1c2ef83c 100644
> > --- a/drivers/md/md-bitmap.c
> > +++ b/drivers/md/md-bitmap.c
> > @@ -862,21 +862,12 @@ static void md_bitmap_file_unmap(struct bitmap_storage *store)
> >    */
> >   static void md_bitmap_file_kick(struct bitmap *bitmap)
> >   {
> > -     char *path, *ptr = NULL;
> > -
> >       if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
> >               md_bitmap_update_sb(bitmap);
> >
> >               if (bitmap->storage.file) {
> > -                     path = kmalloc(PAGE_SIZE, GFP_KERNEL);
> > -                     if (path)
> > -                             ptr = file_path(bitmap->storage.file,
> > -                                          path, PAGE_SIZE);
> > -
> > -                     pr_warn("%s: kicking failed bitmap file %s from array!\n",
> > -                             bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
> > -
> > -                     kfree(path);
> > +                     pr_warn("%s: kicking failed bitmap file %pD from array!\n",
> > +                             bmname(bitmap), bitmap->storage.file);

This is neat!

Acked-by: Song Liu <song@kernel.org>




> >               } else
> >                       pr_warn("%s: disabling internal bitmap due to errors\n",
> >                               bmname(bitmap));
>
> Looks good,  Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>