[PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with '%pD' specifier

[PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with '%pD' specifier

[Jia He]

After the behavior of '%pD' is change to print the full path of file,
iomap_swapfile_fail() can be simplified.

Given the space with proper length would be allocated in vprintk_store(),
the kmalloc() is not required any more.

Besides, the previous number postfix of '%pD' in format string is
pointless.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jia He <justin.he@arm.com>
---
 fs/iomap/direct-io.c | 2 +-
 fs/iomap/swapfile.c  | 8 +-------
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 9398b8c31323..e876a5f9d888 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -426,7 +426,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
 		 * iomap_apply() call in the DIO path, then it will see the
 		 * DELALLOC block that the page-mkwrite allocated.
 		 */
-		pr_warn_ratelimited("Direct I/O collision with buffered writes! File: %pD4 Comm: %.20s\n",
+		pr_warn_ratelimited("Direct I/O collision with buffered writes! File: %pD Comm: %.20s\n",
 				    dio->iocb->ki_filp, current->comm);
 		return -EIO;
 	default:
diff --git a/fs/iomap/swapfile.c b/fs/iomap/swapfile.c
index 6250ca6a1f85..17032c14e466 100644
--- a/fs/iomap/swapfile.c
+++ b/fs/iomap/swapfile.c
@@ -73,13 +73,7 @@ static int iomap_swapfile_add_extent(struct iomap_swapfile_info *isi)
 
 static int iomap_swapfile_fail(struct iomap_swapfile_info *isi, const char *str)
 {
-	char *buf, *p = ERR_PTR(-ENOMEM);
-
-	buf = kmalloc(PATH_MAX, GFP_KERNEL);
-	if (buf)
-		p = file_path(isi->file, buf, PATH_MAX);
-	pr_err("swapon: file %s %s\n", IS_ERR(p) ? "<unknown>" : p, str);
-	kfree(buf);
+	pr_err("swapon: file %pD %s\n", isi->file, str);
 	return -EINVAL;
 }
 
-- 
2.17.1

Re: [PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with '%pD' specifier

[Darrick J. Wong]

On Thu, Jul 15, 2021 at 11:15:27AM +0800, Jia He wrote:
> After the behavior of '%pD' is change to print the full path of file,
> iomap_swapfile_fail() can be simplified.
> 
> Given the space with proper length would be allocated in vprintk_store(),
> the kmalloc() is not required any more.
> 
> Besides, the previous number postfix of '%pD' in format string is
> pointless.
> 
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: "Darrick J. Wong" <djwong@kernel.org>
> Cc: linux-xfs@vger.kernel.org
> Cc: linux-fsdevel@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Suggested-by: Christoph Hellwig <hch@infradead.org>
> Signed-off-by: Jia He <justin.he@arm.com>

Seems reasonable to me...
Acked-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/direct-io.c | 2 +-
>  fs/iomap/swapfile.c  | 8 +-------
>  2 files changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 9398b8c31323..e876a5f9d888 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -426,7 +426,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
>  		 * iomap_apply() call in the DIO path, then it will see the
>  		 * DELALLOC block that the page-mkwrite allocated.
>  		 */
> -		pr_warn_ratelimited("Direct I/O collision with buffered writes! File: %pD4 Comm: %.20s\n",
> +		pr_warn_ratelimited("Direct I/O collision with buffered writes! File: %pD Comm: %.20s\n",
>  				    dio->iocb->ki_filp, current->comm);
>  		return -EIO;
>  	default:
> diff --git a/fs/iomap/swapfile.c b/fs/iomap/swapfile.c
> index 6250ca6a1f85..17032c14e466 100644
> --- a/fs/iomap/swapfile.c
> +++ b/fs/iomap/swapfile.c
> @@ -73,13 +73,7 @@ static int iomap_swapfile_add_extent(struct iomap_swapfile_info *isi)
>  
>  static int iomap_swapfile_fail(struct iomap_swapfile_info *isi, const char *str)
>  {
> -	char *buf, *p = ERR_PTR(-ENOMEM);
> -
> -	buf = kmalloc(PATH_MAX, GFP_KERNEL);
> -	if (buf)
> -		p = file_path(isi->file, buf, PATH_MAX);
> -	pr_err("swapon: file %s %s\n", IS_ERR(p) ? "<unknown>" : p, str);
> -	kfree(buf);
> +	pr_err("swapon: file %pD %s\n", isi->file, str);
>  	return -EINVAL;
>  }
>  
> -- 
> 2.17.1
> 

Re: [PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with '%pD' specifier

[Christoph Hellwig]

On Thu, Jul 15, 2021 at 11:15:27AM +0800, Jia He wrote:
> After the behavior of '%pD' is change to print the full path of file,
> iomap_swapfile_fail() can be simplified.
> 
> Given the space with proper length would be allocated in vprintk_store(),
> the kmalloc() is not required any more.
> 
> Besides, the previous number postfix of '%pD' in format string is
> pointless.

This also touched iomap_dio_actor, but the commit og only mentions
iomap_swapfile_fail.

RE: [PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with '%pD' specifier

[Justin He]

Hi Christoph

> -----Original Message-----
> From: Christoph Hellwig <hch@infradead.org>
> Sent: Friday, July 16, 2021 2:11 PM
> To: Justin He <Justin.He@arm.com>
> Cc: linux-kernel@vger.kernel.org; Linus Torvalds <torvalds@linux-
> foundation.org>; Christoph Hellwig <hch@infradead.org>; nd <nd@arm.com>;
> Darrick J. Wong <djwong@kernel.org>; linux-xfs@vger.kernel.org; linux-
> fsdevel@vger.kernel.org
> Subject: Re: [PATCH RFC 07/13] iomap: simplify iomap_swapfile_fail() with
> '%pD' specifier
> 
> On Thu, Jul 15, 2021 at 11:15:27AM +0800, Jia He wrote:
> > After the behavior of '%pD' is change to print the full path of file,
> > iomap_swapfile_fail() can be simplified.
> >
> > Given the space with proper length would be allocated in vprintk_store(),
> > the kmalloc() is not required any more.
> >
> > Besides, the previous number postfix of '%pD' in format string is
> > pointless.
> 
> This also touched iomap_dio_actor, but the commit og only mentions
> iomap_swapfile_fail.
Okay, I will refine the msg in next version.
Thanks


--
Cheers,
Justin (Jia He)