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* [PATCH] nfsd: Replace open-coded conversion of bytes to hex
@ 2025-08-03 21:24 Eric Biggers
  2025-08-04 11:55 ` Jeff Layton
  2025-08-04 14:01 ` Chuck Lever
  0 siblings, 2 replies; 4+ messages in thread
From: Eric Biggers @ 2025-08-03 21:24 UTC (permalink / raw)
  To: Chuck Lever, Jeff Layton, linux-nfs
  Cc: NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey, Eric Biggers

Since the Linux kernel's sprintf() has conversion to hex built-in via
"%*phN", delete md5_to_hex() and just use that.  Also add an explicit
array bound to the dname parameter of nfs4_make_rec_clidname() to make
its size clear.  No functional change.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 fs/nfsd/nfs4recover.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 2231192ec33f5..54f5e5392ef9d 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -90,26 +90,12 @@ static void
 nfs4_reset_creds(const struct cred *original)
 {
 	put_cred(revert_creds(original));
 }
 
-static void
-md5_to_hex(char *out, char *md5)
-{
-	int i;
-
-	for (i=0; i<16; i++) {
-		unsigned char c = md5[i];
-
-		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
-		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
-	}
-	*out = '\0';
-}
-
 static int
-nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
+nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
 {
 	struct xdr_netobj cksum;
 	struct crypto_shash *tfm;
 	int status;
 
@@ -131,11 +117,11 @@ nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
 	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
 					 cksum.data);
 	if (status)
 		goto out;
 
-	md5_to_hex(dname, cksum.data);
+	sprintf(dname, "%*phN", 16, cksum.data);
 
 	status = 0;
 out:
 	kfree(cksum.data);
 	crypto_free_shash(tfm);

base-commit: 186f3edfdd41f2ae87fc40a9ccba52a3bf930994
-- 
2.50.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] nfsd: Replace open-coded conversion of bytes to hex
  2025-08-03 21:24 [PATCH] nfsd: Replace open-coded conversion of bytes to hex Eric Biggers
@ 2025-08-04 11:55 ` Jeff Layton
  2025-08-04 14:01 ` Chuck Lever
  1 sibling, 0 replies; 4+ messages in thread
From: Jeff Layton @ 2025-08-04 11:55 UTC (permalink / raw)
  To: Eric Biggers, Chuck Lever, linux-nfs
  Cc: NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey

On Sun, 2025-08-03 at 14:24 -0700, Eric Biggers wrote:
> Since the Linux kernel's sprintf() has conversion to hex built-in via
> "%*phN", delete md5_to_hex() and just use that.  Also add an explicit
> array bound to the dname parameter of nfs4_make_rec_clidname() to make
> its size clear.  No functional change.
> 
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> ---
>  fs/nfsd/nfs4recover.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index 2231192ec33f5..54f5e5392ef9d 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -90,26 +90,12 @@ static void
>  nfs4_reset_creds(const struct cred *original)
>  {
>  	put_cred(revert_creds(original));
>  }
>  
> -static void
> -md5_to_hex(char *out, char *md5)
> -{
> -	int i;
> -
> -	for (i=0; i<16; i++) {
> -		unsigned char c = md5[i];
> -
> -		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
> -		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
> -	}
> -	*out = '\0';
> -}
> -
>  static int
> -nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
> +nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
>  {
>  	struct xdr_netobj cksum;
>  	struct crypto_shash *tfm;
>  	int status;
>  
> @@ -131,11 +117,11 @@ nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
>  	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
>  					 cksum.data);
>  	if (status)
>  		goto out;
>  
> -	md5_to_hex(dname, cksum.data);
> +	sprintf(dname, "%*phN", 16, cksum.data);
>  
>  	status = 0;
>  out:
>  	kfree(cksum.data);
>  	crypto_free_shash(tfm);
> 
> base-commit: 186f3edfdd41f2ae87fc40a9ccba52a3bf930994

Reviewed-by: Jeff Layton <jlayton@kernel.org>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] nfsd: Replace open-coded conversion of bytes to hex
  2025-08-03 21:24 [PATCH] nfsd: Replace open-coded conversion of bytes to hex Eric Biggers
  2025-08-04 11:55 ` Jeff Layton
@ 2025-08-04 14:01 ` Chuck Lever
  2025-08-04 22:51   ` Eric Biggers
  1 sibling, 1 reply; 4+ messages in thread
From: Chuck Lever @ 2025-08-04 14:01 UTC (permalink / raw)
  To: Eric Biggers, Jeff Layton, linux-nfs
  Cc: NeilBrown, Olga Kornievskaia, Dai Ngo, Tom Talpey

On 8/3/25 5:24 PM, Eric Biggers wrote:
> Since the Linux kernel's sprintf() has conversion to hex built-in via
> "%*phN", delete md5_to_hex() and just use that.  Also add an explicit
> array bound to the dname parameter of nfs4_make_rec_clidname() to make
> its size clear.  No functional change.
> 
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> ---
>  fs/nfsd/nfs4recover.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index 2231192ec33f5..54f5e5392ef9d 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -90,26 +90,12 @@ static void
>  nfs4_reset_creds(const struct cred *original)
>  {
>  	put_cred(revert_creds(original));
>  }
>  
> -static void
> -md5_to_hex(char *out, char *md5)
> -{
> -	int i;
> -
> -	for (i=0; i<16; i++) {
> -		unsigned char c = md5[i];
> -
> -		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
> -		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
> -	}
> -	*out = '\0';
> -}
> -
>  static int
> -nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
> +nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
>  {
>  	struct xdr_netobj cksum;
>  	struct crypto_shash *tfm;
>  	int status;
>  
> @@ -131,11 +117,11 @@ nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
>  	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
>  					 cksum.data);
>  	if (status)
>  		goto out;
>  
> -	md5_to_hex(dname, cksum.data);
> +	sprintf(dname, "%*phN", 16, cksum.data);

Hello Eric,

Can the raw "16" be replaced with "HEXDIR_LEN / 2" ?


>  	status = 0;
>  out:
>  	kfree(cksum.data);
>  	crypto_free_shash(tfm);
> 
> base-commit: 186f3edfdd41f2ae87fc40a9ccba52a3bf930994


-- 
Chuck Lever

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] nfsd: Replace open-coded conversion of bytes to hex
  2025-08-04 14:01 ` Chuck Lever
@ 2025-08-04 22:51   ` Eric Biggers
  0 siblings, 0 replies; 4+ messages in thread
From: Eric Biggers @ 2025-08-04 22:51 UTC (permalink / raw)
  To: Chuck Lever
  Cc: Jeff Layton, linux-nfs, NeilBrown, Olga Kornievskaia, Dai Ngo,
	Tom Talpey

On Mon, Aug 04, 2025 at 10:01:49AM -0400, Chuck Lever wrote:
> On 8/3/25 5:24 PM, Eric Biggers wrote:
> > Since the Linux kernel's sprintf() has conversion to hex built-in via
> > "%*phN", delete md5_to_hex() and just use that.  Also add an explicit
> > array bound to the dname parameter of nfs4_make_rec_clidname() to make
> > its size clear.  No functional change.
> > 
> > Signed-off-by: Eric Biggers <ebiggers@kernel.org>
> > ---
> >  fs/nfsd/nfs4recover.c | 18 ++----------------
> >  1 file changed, 2 insertions(+), 16 deletions(-)
> > 
> > diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> > index 2231192ec33f5..54f5e5392ef9d 100644
> > --- a/fs/nfsd/nfs4recover.c
> > +++ b/fs/nfsd/nfs4recover.c
> > @@ -90,26 +90,12 @@ static void
> >  nfs4_reset_creds(const struct cred *original)
> >  {
> >  	put_cred(revert_creds(original));
> >  }
> >  
> > -static void
> > -md5_to_hex(char *out, char *md5)
> > -{
> > -	int i;
> > -
> > -	for (i=0; i<16; i++) {
> > -		unsigned char c = md5[i];
> > -
> > -		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
> > -		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
> > -	}
> > -	*out = '\0';
> > -}
> > -
> >  static int
> > -nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
> > +nfs4_make_rec_clidname(char dname[HEXDIR_LEN], const struct xdr_netobj *clname)
> >  {
> >  	struct xdr_netobj cksum;
> >  	struct crypto_shash *tfm;
> >  	int status;
> >  
> > @@ -131,11 +117,11 @@ nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
> >  	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
> >  					 cksum.data);
> >  	if (status)
> >  		goto out;
> >  
> > -	md5_to_hex(dname, cksum.data);
> > +	sprintf(dname, "%*phN", 16, cksum.data);
> 
> Hello Eric,
> 
> Can the raw "16" be replaced with "HEXDIR_LEN / 2" ?
> 
> 
> >  	status = 0;
> >  out:
> >  	kfree(cksum.data);
> >  	crypto_free_shash(tfm);
> > 
> > base-commit: 186f3edfdd41f2ae87fc40a9ccba52a3bf930994

It's the same 16 as was there before.  It really should be
MD5_DIGEST_SIZE, but there are a few more things to clean up regarding
that.  I didn't want to bloat the scope of this patch.

I sent a new series with this patch unchanged, but the digest size stuff
cleaned up in another patch.

- Eric

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2025-08-04 22:51 UTC | newest]

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2025-08-03 21:24 [PATCH] nfsd: Replace open-coded conversion of bytes to hex Eric Biggers
2025-08-04 11:55 ` Jeff Layton
2025-08-04 14:01 ` Chuck Lever
2025-08-04 22:51   ` Eric Biggers

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