[PATCH] FIX: Changes in '0' case for reshape position verification

[PATCH] FIX: Changes in '0' case for reshape position verification

[Adam Kwolek]

Reading sysfs entry that is '0' long should cause an error.
Reshape position cannot be empty.

Absence of reshape position should be ignored. It is possible
that we are about raid0 reshape continuation and it is before takeover.
This means that according metadata (changed by mdmon) it should be reshaped
but md knows nothing about it at this moment. Reshape continuation
in reshape_array() will change it to raid4 and reshape position appears
in sysfs.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
---

 Grow.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Grow.c b/Grow.c
index 53a7cad..239b50d 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1876,9 +1876,12 @@ static int verify_reshape_position(struct mdinfo *info, int level)
 {
 	int ret_val = 0;
 	char buf[40];
+	int rv;
 
 	/* read sync_max, failure can mean raid0 array */
-	if (sysfs_get_str(info, NULL, "sync_max", buf, 40) > 0) {
+	rv = sysfs_get_str(info, NULL, "sync_max", buf, 40);
+
+	if (rv > 0) {
 		char *ep;
 		unsigned long long position = strtoull(buf, &ep, 0);
 
@@ -1906,6 +1909,11 @@ static int verify_reshape_position(struct mdinfo *info, int level)
 				ret_val = 1;
 			}
 		}
+	} else if (rv == 0) {
+		/* for valid sysfs entry, 0-length content
+		 * should be indicated as error
+		 */
+		ret_val = -1;
 	}
 
 	return ret_val;
@@ -3975,7 +3983,7 @@ int Grow_continue_command(char *devname, int fd,
 	 * correct position
 	 */
 	if (verify_reshape_position(content,
-				    map_name(pers, mdstat->level)) <= 0) {
+				    map_name(pers, mdstat->level)) < 0) {
 		ret_val = 1;
 		goto Grow_continue_command_exit;
 	}

Re: [PATCH] FIX: Changes in '0' case for reshape position verification

[NeilBrown]

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On Thu, 16 Feb 2012 14:16:04 +0100 Adam Kwolek <adam.kwolek@intel.com> wrote:

> Reading sysfs entry that is '0' long should cause an error.
> Reshape position cannot be empty.
> 
> Absence of reshape position should be ignored. It is possible
> that we are about raid0 reshape continuation and it is before takeover.
> This means that according metadata (changed by mdmon) it should be reshaped
> but md knows nothing about it at this moment. Reshape continuation
> in reshape_array() will change it to raid4 and reshape position appears
> in sysfs.
> 
> Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>

Thanks.  Applied.

NeilBrown


> ---
> 
>  Grow.c |   12 ++++++++++--
>  1 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/Grow.c b/Grow.c
> index 53a7cad..239b50d 100644
> --- a/Grow.c
> +++ b/Grow.c
> @@ -1876,9 +1876,12 @@ static int verify_reshape_position(struct mdinfo *info, int level)
>  {
>  	int ret_val = 0;
>  	char buf[40];
> +	int rv;
>  
>  	/* read sync_max, failure can mean raid0 array */
> -	if (sysfs_get_str(info, NULL, "sync_max", buf, 40) > 0) {
> +	rv = sysfs_get_str(info, NULL, "sync_max", buf, 40);
> +
> +	if (rv > 0) {
>  		char *ep;
>  		unsigned long long position = strtoull(buf, &ep, 0);
>  
> @@ -1906,6 +1909,11 @@ static int verify_reshape_position(struct mdinfo *info, int level)
>  				ret_val = 1;
>  			}
>  		}
> +	} else if (rv == 0) {
> +		/* for valid sysfs entry, 0-length content
> +		 * should be indicated as error
> +		 */
> +		ret_val = -1;
>  	}
>  
>  	return ret_val;
> @@ -3975,7 +3983,7 @@ int Grow_continue_command(char *devname, int fd,
>  	 * correct position
>  	 */
>  	if (verify_reshape_position(content,
> -				    map_name(pers, mdstat->level)) <= 0) {
> +				    map_name(pers, mdstat->level)) < 0) {
>  		ret_val = 1;
>  		goto Grow_continue_command_exit;
>  	}
> 
> --
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