[PATCH] libxfs: don't pass negative errnos to strerror()

[PATCH] libxfs: don't pass negative errnos to strerror()

[Eric Sandeen]

The error negation work in 12b5319 tripped up a little bit
when we're reporting errors via strerror().  By negating
the error before passing it to strerror, we get i.e.

   mkfs.xfs: pwrite64 failed: Unknown error -22

Keep the error positive, but return -error, just as we
do in the else clauses in these functions.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
index 7a04985..7b23394 100644
--- a/libxfs/rdwr.c
+++ b/libxfs/rdwr.c
@@ -913,12 +913,12 @@ __read_buf(int fd, void *buf, int len, off64_t offset, int flags)
 
 	sts = pread64(fd, buf, len, offset);
 	if (sts < 0) {
-		int error = -errno;
+		int error = errno;
 		fprintf(stderr, _("%s: read failed: %s\n"),
 			progname, strerror(error));
 		if (flags & LIBXFS_EXIT_ON_FAILURE)
 			exit(1);
-		return error;
+		return -error;
 	} else if (sts != len) {
 		fprintf(stderr, _("%s: error - read only %d of %d bytes\n"),
 			progname, sts, len);
@@ -1081,12 +1081,12 @@ __write_buf(int fd, void *buf, int len, off64_t offset, int flags)
 
 	sts = pwrite64(fd, buf, len, offset);
 	if (sts < 0) {
-		int error = -errno;
+		int error = errno;
 		fprintf(stderr, _("%s: pwrite64 failed: %s\n"),
 			progname, strerror(error));
 		if (flags & LIBXFS_B_EXIT)
 			exit(1);
-		return error;
+		return -error;
 	} else if (sts != len) {
 		fprintf(stderr, _("%s: error - pwrite64 only %d of %d bytes\n"),
 			progname, sts, len);

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Re: [PATCH] libxfs: don't pass negative errnos to strerror()

[Carlos Maiolino]

This looks good to me, and simple enough.

consider it

Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

On Thu, Jan 14, 2016 at 10:35:53AM -0600, Eric Sandeen wrote:
> The error negation work in 12b5319 tripped up a little bit
> when we're reporting errors via strerror().  By negating
> the error before passing it to strerror, we get i.e.
> 
>    mkfs.xfs: pwrite64 failed: Unknown error -22
> 
> Keep the error positive, but return -error, just as we
> do in the else clauses in these functions.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
> index 7a04985..7b23394 100644
> --- a/libxfs/rdwr.c
> +++ b/libxfs/rdwr.c
> @@ -913,12 +913,12 @@ __read_buf(int fd, void *buf, int len, off64_t offset, int flags)
>  
>  	sts = pread64(fd, buf, len, offset);
>  	if (sts < 0) {
> -		int error = -errno;
> +		int error = errno;
>  		fprintf(stderr, _("%s: read failed: %s\n"),
>  			progname, strerror(error));
>  		if (flags & LIBXFS_EXIT_ON_FAILURE)
>  			exit(1);
> -		return error;
> +		return -error;
>  	} else if (sts != len) {
>  		fprintf(stderr, _("%s: error - read only %d of %d bytes\n"),
>  			progname, sts, len);
> @@ -1081,12 +1081,12 @@ __write_buf(int fd, void *buf, int len, off64_t offset, int flags)
>  
>  	sts = pwrite64(fd, buf, len, offset);
>  	if (sts < 0) {
> -		int error = -errno;
> +		int error = errno;
>  		fprintf(stderr, _("%s: pwrite64 failed: %s\n"),
>  			progname, strerror(error));
>  		if (flags & LIBXFS_B_EXIT)
>  			exit(1);
> -		return error;
> +		return -error;
>  	} else if (sts != len) {
>  		fprintf(stderr, _("%s: error - pwrite64 only %d of %d bytes\n"),
>  			progname, sts, len);
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs

-- 
Carlos

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