Re: [PATCH 18/20] staging: lustre: llite: Remove filtering of seclabel xattr

[James Simmons]

> From: Robin Humble <plaguedbypenguins@xxxxxxxxx>
> 
> The security.capability xattr is used to implement File
> Capabilities in recent Linux versions. Capabilities are a
> fine grained approach to granting executables elevated
> privileges. eg. /bin/ping can have capabilities
> cap_net_admin, cap_net_raw+ep instead of being setuid root.
> 
> This xattr has long been filtered out by llite, initially for
> stability reasons (b15587), and later over performance
> concerns as this xattr is read for every file with eg.
> 'ls --color'. Since LU-2869 xattr's are cached on clients,
> alleviating most performance concerns.
> 
> Removing llite's filtering of the security.capability xattr
> enables using Lustre as a root filesystem, which is used on
> some large clusters.

The commit message for this patch is incorrect. Some how it got
mixed up with another patch which I missed in this push. Please
drop this patch and I will resent the correct patches later.
 
> Signed-off-by: Robin Humble <plaguedbypenguins@xxxxxxxxx>
> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-9562
> Reviewed-on: https://review.whamcloud.com/27292
> Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx>
> Reviewed-by: Sebastien Buisson <sbuisson@xxxxxxx>
> Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
> Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
> ---
>  drivers/staging/lustre/lustre/llite/file.c         | 58 ++++++++++++++++++++++
>  .../staging/lustre/lustre/llite/llite_internal.h   |  4 ++
>  drivers/staging/lustre/lustre/llite/namei.c        |  6 +++
>  3 files changed, 68 insertions(+)
> 
> diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
> index 215479a..a324580 100644
> --- a/drivers/staging/lustre/lustre/llite/file.c
> +++ b/drivers/staging/lustre/lustre/llite/file.c
> @@ -3040,6 +3040,61 @@ struct posix_acl *ll_get_acl(struct inode *inode, int type)
>  	return acl;
>  }
>  
> +#ifdef CONFIG_FS_POSIX_ACL
> +int ll_set_acl(struct inode *inode, struct posix_acl *acl, int type)
> +{
> +	const char *name = NULL;
> +	char *value = NULL;
> +	size_t size = 0;
> +	int rc = 0;
> +
> +	switch (type) {
> +	case ACL_TYPE_ACCESS:
> +		if (acl) {
> +			rc = posix_acl_update_mode(inode, &inode->i_mode, &acl);
> +			if (rc)
> +				goto out;
> +		}
> +		name = XATTR_NAME_POSIX_ACL_ACCESS;
> +		break;
> +	case ACL_TYPE_DEFAULT:
> +		if (!S_ISDIR(inode->i_mode)) {
> +			rc = acl ? -EACCES : 0;
> +			goto out;
> +		}
> +		name = XATTR_NAME_POSIX_ACL_DEFAULT;
> +		break;
> +	default:
> +		rc = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (acl) {
> +		size = posix_acl_xattr_size(acl->a_count);
> +		value = kmalloc(size, GFP_NOFS);
> +		if (!value) {
> +			rc = -ENOMEM;
> +			goto out;
> +		}
> +
> +		rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
> +		if (rc < 0)
> +			goto out_free;
> +	}
> +
> +	/* dentry is only used for *.lov attributes so it's safe to be NULL */
> +	rc = __vfs_setxattr(NULL, inode, name, value, size, XATTR_CREATE);
> +out_free:
> +	kfree(value);
> +out:
> +	if (!rc)
> +		set_cached_acl(inode, type, acl);
> +	else
> +		forget_cached_acl(inode, type);
> +	return rc;
> +}
> +#endif /* CONFIG_FS_POSIX_ACL */
> +
>  int ll_inode_permission(struct inode *inode, int mask)
>  {
>  	struct ll_sb_info *sbi;
> @@ -3162,6 +3217,9 @@ int ll_inode_permission(struct inode *inode, int mask)
>  	.listxattr	= ll_listxattr,
>  	.fiemap		= ll_fiemap,
>  	.get_acl	= ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> +	.set_acl	= ll_set_acl,
> +#endif
>  };
>  
>  /* dynamic ioctl number support routines */
> diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
> index cd3311a..b3374bc 100644
> --- a/drivers/staging/lustre/lustre/llite/llite_internal.h
> +++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
> @@ -752,6 +752,10 @@ enum ldlm_mode ll_take_md_lock(struct inode *inode, __u64 bits,
>  int ll_getattr(const struct path *path, struct kstat *stat,
>  	       u32 request_mask, unsigned int flags);
>  struct posix_acl *ll_get_acl(struct inode *inode, int type);
> +#ifdef CONFIG_FS_POSIX_ACL
> +int ll_set_acl(struct inode *inode, struct posix_acl *acl, int type);
> +#endif /* CONFIG_FS_POSIX_ACL */
> +
>  int ll_migrate(struct inode *parent, struct file *file, int mdtidx,
>  	       const char *name, int namelen);
>  int ll_get_fid_by_name(struct inode *parent, const char *name,
> diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
> index a208a8b..14dccbe 100644
> --- a/drivers/staging/lustre/lustre/llite/namei.c
> +++ b/drivers/staging/lustre/lustre/llite/namei.c
> @@ -1187,6 +1187,9 @@ static int ll_rename(struct inode *src, struct dentry *src_dchild,
>  	.permission	 = ll_inode_permission,
>  	.listxattr	  = ll_listxattr,
>  	.get_acl	    = ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> +	.set_acl	= ll_set_acl,
> +#endif
>  };
>  
>  const struct inode_operations ll_special_inode_operations = {
> @@ -1195,4 +1198,7 @@ static int ll_rename(struct inode *src, struct dentry *src_dchild,
>  	.permission     = ll_inode_permission,
>  	.listxattr      = ll_listxattr,
>  	.get_acl	    = ll_get_acl,
> +#ifdef CONFIG_FS_POSIX_ACL
> +	.set_acl	= ll_set_acl,
> +#endif
>  };
> -- 
> 1.8.3.1
> 
>