Re: [PATCH v2] src/attr_replace_test: dynamically adjust the max xattr size

[Xiubo Li <xiubli@redhat.com>]

On 6/8/22 12:51 AM, Luís Henriques wrote:
> CephFS doesn't had a maximum xattr size.  Instead, it imposes a maximum size
> for the full set of xattrs names+values, which by default is 64K but may be
> changed.
>
> Test generic/486 started to fail after fixing a ceph bug where this limit
> wasn't being imposed.  Adjust dynamically the size of the xattr being set
> if the error returned is -ENOSPC.
>
> Signed-off-by: Luís Henriques <lhenriques@suse.de>
> ---
>   src/attr_replace_test.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/src/attr_replace_test.c b/src/attr_replace_test.c
> index cca8dcf8ff60..d1b92703ba2a 100644
> --- a/src/attr_replace_test.c
> +++ b/src/attr_replace_test.c
> @@ -62,7 +62,10 @@ int main(int argc, char *argv[])
>   
>   	/* Then, replace it with bigger one, forcing short form to leaf conversion. */
>   	memset(value, '1', size);
> -	ret = fsetxattr(fd, name, value, size, XATTR_REPLACE);
> +	do {
> +		ret = fsetxattr(fd, name, value, size, XATTR_REPLACE);
> +		size -= 256;

I am not sure whether will this break other filesystems tests.

Maybe we should get the filesystem type first from 'st_mode', and then 
in ceph case we should minus strlen(name) before replacing the it. And 
then if it fails with '-ENOSPC' do the following ?

Or maybe we could get maximum length of xattr from ioctl(fd) in ceph case ?


> +	} while ((ret < 0) && (errno == ENOSPC) && (size > 256));
>   	if (ret < 0) die();
>   	close(fd);
>   
>