Re: [PATCH] nfsv4: Switch to generic xattr handling code

["J. Bruce Fields" <bfields@fieldses.org>]

On Thu, Dec 09, 2010 at 05:05:25PM +0530, Aneesh Kumar K.V wrote:
> This patch make nfsv4 use the generic xattr handling code
> to get the nfsv4 acl. This will help us to add richacl
> support to nfsv4 in later patches

Look OK to me.--b.

> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  fs/nfs/dir.c      |    8 ++++--
>  fs/nfs/nfs4_fs.h  |    7 +-----
>  fs/nfs/nfs4proc.c |   62 +++++++++++++++++++++++++++++-----------------------
>  fs/nfs/super.c    |    4 ++-
>  4 files changed, 44 insertions(+), 37 deletions(-)
> 
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index 070f368..7e0c0be 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -35,6 +35,7 @@
>  #include <linux/sched.h>
>  #include <linux/vmalloc.h>
>  #include <linux/kmemleak.h>
> +#include <linux/xattr.h>
>  
>  #include "delegation.h"
>  #include "iostat.h"
> @@ -125,9 +126,10 @@ const struct inode_operations nfs4_dir_inode_operations = {
>  	.permission	= nfs_permission,
>  	.getattr	= nfs_getattr,
>  	.setattr	= nfs_setattr,
> -	.getxattr       = nfs4_getxattr,
> -	.setxattr       = nfs4_setxattr,
> -	.listxattr      = nfs4_listxattr,
> +	.getxattr	= generic_getxattr,
> +	.setxattr	= generic_setxattr,
> +	.listxattr	= generic_listxattr,
> +	.removexattr	= generic_removexattr,
>  };
>  
>  #endif /* CONFIG_NFS_V4 */
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index 9fa4963..441fbcd 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -227,12 +227,6 @@ struct nfs4_state_maintenance_ops {
>  extern const struct dentry_operations nfs4_dentry_operations;
>  extern const struct inode_operations nfs4_dir_inode_operations;
>  
> -/* inode.c */
> -extern ssize_t nfs4_getxattr(struct dentry *, const char *, void *, size_t);
> -extern int nfs4_setxattr(struct dentry *, const char *, const void *, size_t, int);
> -extern ssize_t nfs4_listxattr(struct dentry *, char *, size_t);
> -
> -
>  /* nfs4proc.c */
>  extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
>  extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
> @@ -246,6 +240,7 @@ extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fh
>  extern int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name,
>  		struct nfs4_fs_locations *fs_locations, struct page *page);
>  extern void nfs4_release_lockowner(const struct nfs4_lock_state *);
> +extern const struct xattr_handler *nfs4_xattr_handlers[];
>  
>  #if defined(CONFIG_NFS_V4_1)
>  static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server)
> diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> index c57b4e0..9d4839b 100644
> --- a/fs/nfs/nfs4proc.c
> +++ b/fs/nfs/nfs4proc.c
> @@ -49,6 +49,7 @@
>  #include <linux/mount.h>
>  #include <linux/module.h>
>  #include <linux/sunrpc/bc_xprt.h>
> +#include <linux/xattr.h>
>  
>  #include "nfs4_fs.h"
>  #include "delegation.h"
> @@ -4394,42 +4395,36 @@ void nfs4_release_lockowner(const struct nfs4_lock_state *lsp)
>  
>  #define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
>  
> -int nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf,
> -		size_t buflen, int flags)
> +static int nfs4_xattr_set_nfs4_acl(struct dentry *dentry, const char *key,
> +				   const void *buf, size_t buflen,
> +				   int flags, int type)
>  {
> -	struct inode *inode = dentry->d_inode;
> -
> -	if (strcmp(key, XATTR_NAME_NFSV4_ACL) != 0)
> -		return -EOPNOTSUPP;
> +	if (strcmp(key, "") != 0)
> +		return -EINVAL;
>  
> -	return nfs4_proc_set_acl(inode, buf, buflen);
> +	return nfs4_proc_set_acl(dentry->d_inode, buf, buflen);
>  }
>  
> -/* The getxattr man page suggests returning -ENODATA for unknown attributes,
> - * and that's what we'll do for e.g. user attributes that haven't been set.
> - * But we'll follow ext2/ext3's lead by returning -EOPNOTSUPP for unsupported
> - * attributes in kernel-managed attribute namespaces. */
> -ssize_t nfs4_getxattr(struct dentry *dentry, const char *key, void *buf,
> -		size_t buflen)
> +static int nfs4_xattr_get_nfs4_acl(struct dentry *dentry, const char *key,
> +				   void *buf, size_t buflen, int type)
>  {
> -	struct inode *inode = dentry->d_inode;
> -
> -	if (strcmp(key, XATTR_NAME_NFSV4_ACL) != 0)
> -		return -EOPNOTSUPP;
> +	if (strcmp(key, "") != 0)
> +		return -EINVAL;
>  
> -	return nfs4_proc_get_acl(inode, buf, buflen);
> +	return nfs4_proc_get_acl(dentry->d_inode, buf, buflen);
>  }
>  
> -ssize_t nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen)
> +static size_t nfs4_xattr_list_nfs4_acl(struct dentry *dentry, char *list,
> +				       size_t list_len, const char *name,
> +				       size_t name_len, int type)
>  {
> -	size_t len = strlen(XATTR_NAME_NFSV4_ACL) + 1;
> +	size_t len = sizeof(XATTR_NAME_NFSV4_ACL);
>  
>  	if (!nfs4_server_supports_acls(NFS_SERVER(dentry->d_inode)))
>  		return 0;
> -	if (buf && buflen < len)
> -		return -ERANGE;
> -	if (buf)
> -		memcpy(buf, XATTR_NAME_NFSV4_ACL, len);
> +
> +	if (list && len <= list_len)
> +		memcpy(list, XATTR_NAME_NFSV4_ACL, len);
>  	return len;
>  }
>  
> @@ -5500,9 +5495,10 @@ static const struct inode_operations nfs4_file_inode_operations = {
>  	.permission	= nfs_permission,
>  	.getattr	= nfs_getattr,
>  	.setattr	= nfs_setattr,
> -	.getxattr	= nfs4_getxattr,
> -	.setxattr	= nfs4_setxattr,
> -	.listxattr	= nfs4_listxattr,
> +	.getxattr	= generic_getxattr,
> +	.setxattr	= generic_setxattr,
> +	.listxattr	= generic_listxattr,
> +	.removexattr	= generic_removexattr,
>  };
>  
>  const struct nfs_rpc_ops nfs_v4_clientops = {
> @@ -5547,6 +5543,18 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
>  	.open_context	= nfs4_atomic_open,
>  };
>  
> +static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
> +	.prefix	= XATTR_NAME_NFSV4_ACL,
> +	.list	= nfs4_xattr_list_nfs4_acl,
> +	.get	= nfs4_xattr_get_nfs4_acl,
> +	.set	= nfs4_xattr_set_nfs4_acl,
> +};
> +
> +const struct xattr_handler *nfs4_xattr_handlers[] = {
> +	&nfs4_xattr_nfs4_acl_handler,
> +	NULL
> +};
> +
>  /*
>   * Local variables:
>   *  c-basic-offset: 8
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index e57e670..e0f4a9e 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -2503,7 +2503,8 @@ static void nfs4_clone_super(struct super_block *sb,
>  	 * so ourselves when necessary.
>  	 */
>  	sb->s_flags  |= MS_POSIXACL;
> - 	nfs_initialise_sb(sb);
> +	sb->s_xattr  = old_sb->s_xattr;
> +	nfs_initialise_sb(sb);
>  }
>  
>  /*
> @@ -2518,6 +2519,7 @@ static void nfs4_fill_super(struct super_block *sb)
>  	 * so ourselves when necessary.
>  	 */
>  	sb->s_flags  |= MS_POSIXACL;
> +	sb->s_xattr = nfs4_xattr_handlers;
>  	nfs_initialise_sb(sb);
>  }
>  
> -- 
> 1.7.1
>