Merge tag 'v6.4/vfs.acl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull acl updates from Christian Brauner:
 "After finishing the introduction of the new posix acl api last cycle
  the generic POSIX ACL xattr handlers are still around in the
  filesystems xattr handlers for two reasons:

   (1) Because a few filesystems rely on the ->list() method of the
       generic POSIX ACL xattr handlers in their ->listxattr() inode
       operation.

   (2) POSIX ACLs are only available if IOP_XATTR is raised. The
       IOP_XATTR flag is raised in inode_init_always() based on whether
       the sb->s_xattr pointer is non-NULL. IOW, the registered xattr
       handlers of the filesystem are used to raise IOP_XATTR. Removing
       the generic POSIX ACL xattr handlers from all filesystems would
       risk regressing filesystems that only implement POSIX ACL support
       and no other xattrs (nfs3 comes to mind).

  This contains the work to decouple POSIX ACLs from the IOP_XATTR flag
  as they don't depend on xattr handlers anymore. So it's now possible
  to remove the generic POSIX ACL xattr handlers from the sb->s_xattr
  list of all filesystems. This is a crucial step as the generic POSIX
  ACL xattr handlers aren't used for POSIX ACLs anymore and POSIX ACLs
  don't depend on the xattr infrastructure anymore.

  Adressing problem (1) will require more long-term work. It would be
  best to get rid of the ->list() method of xattr handlers completely at
  some point.

  For erofs, ext{2,4}, f2fs, jffs2, ocfs2, and reiserfs the nop POSIX
  ACL xattr handler is kept around so they can continue to use
  array-based xattr handler indexing.

  This update does simplify the ->listxattr() implementation of all
  these filesystems however"

* tag 'v6.4/vfs.acl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  acl: don't depend on IOP_XATTR
  ovl: check for ->listxattr() support
  reiserfs: rework priv inode handling
  fs: rename generic posix acl handlers
  reiserfs: rework ->listxattr() implementation
  fs: simplify ->listxattr() implementation
  fs: drop unused posix acl handlers
  xattr: remove unused argument
  xattr: add listxattr helper
  xattr: simplify listxattr helpers

fs/9p/xattr.c

@@ -185,10 +185,6 @@ static struct xattr_handler v9fs_xattr_security_handler = {
 const struct xattr_handler *v9fs_xattr_handlers[] = {
 	&v9fs_xattr_user_handler,
 	&v9fs_xattr_trusted_handler,
-#ifdef CONFIG_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 #ifdef CONFIG_9P_FS_SECURITY
 	&v9fs_xattr_security_handler,
 #endif

fs/btrfs/xattr.c

@@ -444,10 +444,6 @@ static const struct xattr_handler btrfs_btrfs_xattr_handler = {
 
 const struct xattr_handler *btrfs_xattr_handlers[] = {
 	&btrfs_security_xattr_handler,
-#ifdef CONFIG_BTRFS_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&btrfs_trusted_xattr_handler,
 	&btrfs_user_xattr_handler,
 	&btrfs_btrfs_xattr_handler,

fs/ceph/xattr.c

@@ -1411,10 +1411,6 @@ void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
  * attributes are handled directly.
  */
 const struct xattr_handler *ceph_xattr_handlers[] = {
-#ifdef CONFIG_CEPH_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&ceph_other_xattr_handler,
 	NULL,
 };

fs/cifs/xattr.c

@@ -487,9 +487,5 @@ const struct xattr_handler *cifs_xattr_handlers[] = {
 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
 	&cifs_cifs_ntsd_full_xattr_handler,
 	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
-#ifdef CONFIG_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	NULL
 };

fs/ecryptfs/inode.c

@@ -1210,10 +1210,6 @@ static const struct xattr_handler ecryptfs_xattr_handler = {
 };
 
 const struct xattr_handler *ecryptfs_xattr_handlers[] = {
-#ifdef CONFIG_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&ecryptfs_xattr_handler,
 	NULL
 };

fs/erofs/xattr.c

@@ -463,10 +463,6 @@ const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
 
 const struct xattr_handler *erofs_xattr_handlers[] = {
 	&erofs_xattr_user_handler,
-#ifdef CONFIG_EROFS_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&erofs_xattr_trusted_handler,
 #ifdef CONFIG_EROFS_FS_SECURITY
 	&erofs_xattr_security_handler,
@@ -490,13 +486,9 @@ static int xattr_entrylist(struct xattr_iter *_it,
 	unsigned int prefix_len;
 	const char *prefix;
 
-	const struct xattr_handler *h =
-		erofs_xattr_handler(entry->e_name_index);
-
-	if (!h || (h->list && !h->list(it->dentry)))
+	prefix = erofs_xattr_prefix(entry->e_name_index, it->dentry);
+	if (!prefix)
 		return 1;
-
-	prefix = xattr_prefix(h);
 	prefix_len = strlen(prefix);
 
 	if (!it->buffer) {

fs/erofs/xattr.h

@@ -41,15 +41,16 @@ extern const struct xattr_handler erofs_xattr_user_handler;
 extern const struct xattr_handler erofs_xattr_trusted_handler;
 extern const struct xattr_handler erofs_xattr_security_handler;
 
-static inline const struct xattr_handler *erofs_xattr_handler(unsigned int idx)
+static inline const char *erofs_xattr_prefix(unsigned int idx,
+					     struct dentry *dentry)
 {
+	const struct xattr_handler *handler = NULL;
+
 	static const struct xattr_handler *xattr_handler_map[] = {
 		[EROFS_XATTR_INDEX_USER] = &erofs_xattr_user_handler,
 #ifdef CONFIG_EROFS_FS_POSIX_ACL
-		[EROFS_XATTR_INDEX_POSIX_ACL_ACCESS] =
-			&posix_acl_access_xattr_handler,
-		[EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT] =
-			&posix_acl_default_xattr_handler,
+		[EROFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &nop_posix_acl_access,
+		[EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
 #endif
 		[EROFS_XATTR_INDEX_TRUSTED] = &erofs_xattr_trusted_handler,
 #ifdef CONFIG_EROFS_FS_SECURITY
@@ -57,8 +58,13 @@ static inline const struct xattr_handler *erofs_xattr_handler(unsigned int idx)
 #endif
 	};
 
-	return idx && idx < ARRAY_SIZE(xattr_handler_map) ?
-		xattr_handler_map[idx] : NULL;
+	if (idx && idx < ARRAY_SIZE(xattr_handler_map))
+		handler = xattr_handler_map[idx];
+
+	if (!xattr_handler_can_list(handler, dentry))
+		return NULL;
+
+	return xattr_prefix(handler);
 }
 
 extern const struct xattr_handler *erofs_xattr_handlers[];

fs/ext2/xattr.c

@@ -101,8 +101,8 @@ static void ext2_xattr_rehash(struct ext2_xattr_header *,
 static const struct xattr_handler *ext2_xattr_handler_map[] = {
 	[EXT2_XATTR_INDEX_USER]		     = &ext2_xattr_user_handler,
 #ifdef CONFIG_EXT2_FS_POSIX_ACL
-	[EXT2_XATTR_INDEX_POSIX_ACL_ACCESS]  = &posix_acl_access_xattr_handler,
-	[EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+	[EXT2_XATTR_INDEX_POSIX_ACL_ACCESS]  = &nop_posix_acl_access,
+	[EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
 #endif
 	[EXT2_XATTR_INDEX_TRUSTED]	     = &ext2_xattr_trusted_handler,
 #ifdef CONFIG_EXT2_FS_SECURITY
@@ -113,10 +113,6 @@ static const struct xattr_handler *ext2_xattr_handler_map[] = {
 const struct xattr_handler *ext2_xattr_handlers[] = {
 	&ext2_xattr_user_handler,
 	&ext2_xattr_trusted_handler,
-#ifdef CONFIG_EXT2_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 #ifdef CONFIG_EXT2_FS_SECURITY
 	&ext2_xattr_security_handler,
 #endif
@@ -125,14 +121,18 @@ const struct xattr_handler *ext2_xattr_handlers[] = {
 
 #define EA_BLOCK_CACHE(inode)	(EXT2_SB(inode->i_sb)->s_ea_block_cache)
 
-static inline const struct xattr_handler *
-ext2_xattr_handler(int name_index)
+static inline const char *ext2_xattr_prefix(int name_index,
+					    struct dentry *dentry)
 {
 	const struct xattr_handler *handler = NULL;
 
 	if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
 		handler = ext2_xattr_handler_map[name_index];
-	return handler;
+
+	if (!xattr_handler_can_list(handler, dentry))
+		return NULL;
+
+	return xattr_prefix(handler);
 }
 
 static bool
@@ -333,11 +333,10 @@ ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
 	/* list the attribute names */
 	for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
 	     entry = EXT2_XATTR_NEXT(entry)) {
-		const struct xattr_handler *handler =
-			ext2_xattr_handler(entry->e_name_index);
+		const char *prefix;
 
-		if (handler && (!handler->list || handler->list(dentry))) {
-			const char *prefix = handler->prefix ?: handler->name;
+		prefix = ext2_xattr_prefix(entry->e_name_index, dentry);
+		if (prefix) {
 			size_t prefix_len = strlen(prefix);
 			size_t size = prefix_len + entry->e_name_len + 1;
 

fs/ext4/xattr.c

@@ -88,8 +88,8 @@ static void ext4_xattr_rehash(struct ext4_xattr_header *);
 static const struct xattr_handler * const ext4_xattr_handler_map[] = {
 	[EXT4_XATTR_INDEX_USER]		     = &ext4_xattr_user_handler,
 #ifdef CONFIG_EXT4_FS_POSIX_ACL
-	[EXT4_XATTR_INDEX_POSIX_ACL_ACCESS]  = &posix_acl_access_xattr_handler,
-	[EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+	[EXT4_XATTR_INDEX_POSIX_ACL_ACCESS]  = &nop_posix_acl_access,
+	[EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
 #endif
 	[EXT4_XATTR_INDEX_TRUSTED]	     = &ext4_xattr_trusted_handler,
 #ifdef CONFIG_EXT4_FS_SECURITY
@@ -101,10 +101,6 @@ static const struct xattr_handler * const ext4_xattr_handler_map[] = {
 const struct xattr_handler *ext4_xattr_handlers[] = {
 	&ext4_xattr_user_handler,
 	&ext4_xattr_trusted_handler,
-#ifdef CONFIG_EXT4_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 #ifdef CONFIG_EXT4_FS_SECURITY
 	&ext4_xattr_security_handler,
 #endif
@@ -173,14 +169,18 @@ static void ext4_xattr_block_csum_set(struct inode *inode,
 						bh->b_blocknr, BHDR(bh));
 }
 
-static inline const struct xattr_handler *
-ext4_xattr_handler(int name_index)
+static inline const char *ext4_xattr_prefix(int name_index,
+					    struct dentry *dentry)
 {
 	const struct xattr_handler *handler = NULL;
 
 	if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
 		handler = ext4_xattr_handler_map[name_index];
-	return handler;
+
+	if (!xattr_handler_can_list(handler, dentry))
+		return NULL;
+
+	return xattr_prefix(handler);
 }
 
 static int
@@ -740,11 +740,10 @@ ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
 	size_t rest = buffer_size;
 
 	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
-		const struct xattr_handler *handler =
-			ext4_xattr_handler(entry->e_name_index);
+		const char *prefix;
 
-		if (handler && (!handler->list || handler->list(dentry))) {
-			const char *prefix = handler->prefix ?: handler->name;
+		prefix = ext4_xattr_prefix(entry->e_name_index, dentry);
+		if (prefix) {
 			size_t prefix_len = strlen(prefix);
 			size_t size = prefix_len + entry->e_name_len + 1;
 

fs/f2fs/xattr.c

@@ -192,8 +192,8 @@ const struct xattr_handler f2fs_xattr_security_handler = {
 static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 	[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
 #ifdef CONFIG_F2FS_FS_POSIX_ACL
-	[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
-	[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+	[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &nop_posix_acl_access,
+	[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default,
 #endif
 	[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
 #ifdef CONFIG_F2FS_FS_SECURITY
@@ -204,10 +204,6 @@ static const struct xattr_handler *f2fs_xattr_handler_map[] = {
 
 const struct xattr_handler *f2fs_xattr_handlers[] = {
 	&f2fs_xattr_user_handler,
-#ifdef CONFIG_F2FS_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&f2fs_xattr_trusted_handler,
 #ifdef CONFIG_F2FS_FS_SECURITY
 	&f2fs_xattr_security_handler,
@@ -216,13 +212,18 @@ const struct xattr_handler *f2fs_xattr_handlers[] = {
 	NULL,
 };
 
-static inline const struct xattr_handler *f2fs_xattr_handler(int index)
+static inline const char *f2fs_xattr_prefix(int index,
+					    struct dentry *dentry)
 {
 	const struct xattr_handler *handler = NULL;
 
 	if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
 		handler = f2fs_xattr_handler_map[index];
-	return handler;
+
+	if (!xattr_handler_can_list(handler, dentry))
+		return NULL;
+
+	return xattr_prefix(handler);
 }
 
 static struct f2fs_xattr_entry *__find_xattr(void *base_addr,
@@ -573,12 +574,12 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 	last_base_addr = (void *)base_addr + XATTR_SIZE(inode);
 
 	list_for_each_xattr(entry, base_addr) {
-		const struct xattr_handler *handler =
-			f2fs_xattr_handler(entry->e_name_index);
 		const char *prefix;
 		size_t prefix_len;
 		size_t size;
 
+		prefix = f2fs_xattr_prefix(entry->e_name_index, dentry);
+
 		if ((void *)(entry) + sizeof(__u32) > last_base_addr ||
 			(void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) {
 			f2fs_err(F2FS_I_SB(inode), "inode (%lu) has corrupted xattr",
@@ -590,10 +591,9 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 			goto cleanup;
 		}
 
-		if (!handler || (handler->list && !handler->list(dentry)))
+		if (!prefix)
 			continue;
 
-		prefix = xattr_prefix(handler);
 		prefix_len = strlen(prefix);
 		size = prefix_len + entry->e_name_len + 1;
 		if (buffer) {

fs/gfs2/xattr.c

@@ -1501,8 +1501,6 @@ const struct xattr_handler *gfs2_xattr_handlers_max[] = {
 	/* GFS2_FS_FORMAT_MIN */
 	&gfs2_xattr_user_handler,
 	&gfs2_xattr_security_handler,
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
 	NULL,
 };
 

fs/jffs2/xattr.c

@@ -919,17 +919,14 @@ const struct xattr_handler *jffs2_xattr_handlers[] = {
 	&jffs2_user_xattr_handler,
 #ifdef CONFIG_JFFS2_FS_SECURITY
 	&jffs2_security_xattr_handler,
-#endif
-#ifdef CONFIG_JFFS2_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
 #endif
 	&jffs2_trusted_xattr_handler,
 	NULL
 };
 
-static const struct xattr_handler *xprefix_to_handler(int xprefix) {
-	const struct xattr_handler *ret;
+static const char *jffs2_xattr_prefix(int xprefix, struct dentry *dentry)
+{
+	const struct xattr_handler *ret = NULL;
 
 	switch (xprefix) {
 	case JFFS2_XPREFIX_USER:
@@ -942,20 +939,23 @@ static const struct xattr_handler *xprefix_to_handler(int xprefix) {
 #endif
 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 	case JFFS2_XPREFIX_ACL_ACCESS:
-		ret = &posix_acl_access_xattr_handler;
+		ret = &nop_posix_acl_access;
 		break;
 	case JFFS2_XPREFIX_ACL_DEFAULT:
-		ret = &posix_acl_default_xattr_handler;
+		ret = &nop_posix_acl_default;
 		break;
 #endif
 	case JFFS2_XPREFIX_TRUSTED:
 		ret = &jffs2_trusted_xattr_handler;
 		break;
 	default:
-		ret = NULL;
-		break;
+		return NULL;
 	}
-	return ret;
+
+	if (!xattr_handler_can_list(ret, dentry))
+		return NULL;
+
+	return xattr_prefix(ret);
 }
 
 ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
@@ -966,7 +966,6 @@ ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 	struct jffs2_inode_cache *ic = f->inocache;
 	struct jffs2_xattr_ref *ref, **pref;
 	struct jffs2_xattr_datum *xd;
-	const struct xattr_handler *xhandle;
 	const char *prefix;
 	ssize_t prefix_len, len, rc;
 	int retry = 0;
@@ -998,10 +997,10 @@ ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 					goto out;
 			}
 		}
-		xhandle = xprefix_to_handler(xd->xprefix);
-		if (!xhandle || (xhandle->list && !xhandle->list(dentry)))
+
+		prefix = jffs2_xattr_prefix(xd->xprefix, dentry);
+		if (!prefix)
 			continue;
-		prefix = xhandle->prefix ?: xhandle->name;
 		prefix_len = strlen(prefix);
 		rc = prefix_len + xd->name_len + 1;
 

fs/jfs/xattr.c

@@ -986,10 +986,6 @@ static const struct xattr_handler jfs_trusted_xattr_handler = {
 };
 
 const struct xattr_handler *jfs_xattr_handlers[] = {
-#ifdef CONFIG_JFS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&jfs_os2_xattr_handler,
 	&jfs_user_xattr_handler,
 	&jfs_security_xattr_handler,

fs/nfs/nfs3_fs.h

@@ -17,7 +17,6 @@ extern int nfs3_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 extern int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 		struct posix_acl *dfacl);
 extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
-extern const struct xattr_handler *nfs3_xattr_handlers[];
 #else
 static inline int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 		struct posix_acl *dfacl)

fs/nfs/nfs3acl.c

@@ -300,12 +300,6 @@ int nfs3_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	goto out;
 }
 
-const struct xattr_handler *nfs3_xattr_handlers[] = {
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-	NULL,
-};
-
 static int
 nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
 		size_t size, ssize_t *result)

fs/nfs/nfs3super.c

@@ -14,9 +14,6 @@ struct nfs_subversion nfs_v3 = {
 	.rpc_vers = &nfs_version3,
 	.rpc_ops  = &nfs_v3_clientops,
 	.sops     = &nfs_sops,
-#ifdef CONFIG_NFS_V3_ACL
-	.xattr    = nfs3_xattr_handlers,
-#endif
 };
 
 static int __init init_nfs_v3(void)

fs/nfsd/nfs4xdr.c

@@ -3446,8 +3446,7 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
 		p = xdr_reserve_space(xdr, 4);
 		if (!p)
 			goto out_resource;
-		err = xattr_supported_namespace(d_inode(dentry),
-						XATTR_USER_PREFIX);
+		err = xattr_supports_user_prefix(d_inode(dentry));
 		*p++ = cpu_to_be32(err == 0);
 	}
 

fs/ntfs3/xattr.c

@@ -1033,10 +1033,6 @@ static const struct xattr_handler ntfs_other_xattr_handler = {
 };
 
 const struct xattr_handler *ntfs_xattr_handlers[] = {
-#ifdef CONFIG_NTFS3_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&ntfs_other_xattr_handler,
 	NULL,
 };

fs/ocfs2/xattr.c

@@ -89,21 +89,17 @@ static struct ocfs2_xattr_def_value_root def_xv = {
 
 const struct xattr_handler *ocfs2_xattr_handlers[] = {
 	&ocfs2_xattr_user_handler,
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
 	&ocfs2_xattr_trusted_handler,
 	&ocfs2_xattr_security_handler,
 	NULL
 };
 
 static const struct xattr_handler *ocfs2_xattr_handler_map[OCFS2_XATTR_MAX] = {
-	[OCFS2_XATTR_INDEX_USER]	= &ocfs2_xattr_user_handler,
-	[OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS]
-					= &posix_acl_access_xattr_handler,
-	[OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT]
-					= &posix_acl_default_xattr_handler,
-	[OCFS2_XATTR_INDEX_TRUSTED]	= &ocfs2_xattr_trusted_handler,
-	[OCFS2_XATTR_INDEX_SECURITY]	= &ocfs2_xattr_security_handler,
+	[OCFS2_XATTR_INDEX_USER]		= &ocfs2_xattr_user_handler,
+	[OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS]	= &nop_posix_acl_access,
+	[OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT]	= &nop_posix_acl_default,
+	[OCFS2_XATTR_INDEX_TRUSTED]		= &ocfs2_xattr_trusted_handler,
+	[OCFS2_XATTR_INDEX_SECURITY]		= &ocfs2_xattr_security_handler,
 };
 
 struct ocfs2_xattr_info {

fs/orangefs/xattr.c

@@ -555,8 +555,6 @@ static const struct xattr_handler orangefs_xattr_default_handler = {
 };
 
 const struct xattr_handler *orangefs_xattr_handlers[] = {
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
 	&orangefs_xattr_default_handler,
 	NULL
 };

fs/overlayfs/copy_up.c

@@ -81,8 +81,7 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de
 	int error = 0;
 	size_t slen;
 
-	if (!(old->d_inode->i_opflags & IOP_XATTR) ||
-	    !(new->d_inode->i_opflags & IOP_XATTR))
+	if (!old->d_inode->i_op->listxattr || !new->d_inode->i_op->listxattr)
 		return 0;
 
 	list_size = vfs_listxattr(old, NULL, 0);

fs/overlayfs/super.c

@@ -1055,20 +1055,12 @@ static const struct xattr_handler ovl_other_xattr_handler = {
 };
 
 static const struct xattr_handler *ovl_trusted_xattr_handlers[] = {
-#ifdef CONFIG_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&ovl_own_trusted_xattr_handler,
 	&ovl_other_xattr_handler,
 	NULL
 };
 
 static const struct xattr_handler *ovl_user_xattr_handlers[] = {
-#ifdef CONFIG_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&ovl_own_user_xattr_handler,
 	&ovl_other_xattr_handler,
 	NULL

fs/posix_acl.c

@@ -957,25 +957,62 @@ set_posix_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 }
 EXPORT_SYMBOL(set_posix_acl);
 
+int posix_acl_listxattr(struct inode *inode, char **buffer,
+			ssize_t *remaining_size)
+{
+	int err;
+
+	if (!IS_POSIXACL(inode))
+		return 0;
+
+	if (inode->i_acl) {
+		err = xattr_list_one(buffer, remaining_size,
+				     XATTR_NAME_POSIX_ACL_ACCESS);
+		if (err)
+			return err;
+	}
+
+	if (inode->i_default_acl) {
+		err = xattr_list_one(buffer, remaining_size,
+				     XATTR_NAME_POSIX_ACL_DEFAULT);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static bool
 posix_acl_xattr_list(struct dentry *dentry)
 {
 	return IS_POSIXACL(d_backing_inode(dentry));
 }
 
-const struct xattr_handler posix_acl_access_xattr_handler = {
+/*
+ * nop_posix_acl_access - legacy xattr handler for access POSIX ACLs
+ *
+ * This is the legacy POSIX ACL access xattr handler. It is used by some
+ * filesystems to implement their ->listxattr() inode operation. New code
+ * should never use them.
+ */
+const struct xattr_handler nop_posix_acl_access = {
 	.name = XATTR_NAME_POSIX_ACL_ACCESS,
-	.flags = ACL_TYPE_ACCESS,
 	.list = posix_acl_xattr_list,
 };
-EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
+EXPORT_SYMBOL_GPL(nop_posix_acl_access);
 
-const struct xattr_handler posix_acl_default_xattr_handler = {
+/*
+ * nop_posix_acl_default - legacy xattr handler for default POSIX ACLs
+ *
+ * This is the legacy POSIX ACL default xattr handler. It is used by some
+ * filesystems to implement their ->listxattr() inode operation. New code
+ * should never use them.
+ */
+const struct xattr_handler nop_posix_acl_default = {
 	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
-	.flags = ACL_TYPE_DEFAULT,
 	.list = posix_acl_xattr_list,
 };
-EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
+EXPORT_SYMBOL_GPL(nop_posix_acl_default);
 
 int simple_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		   struct posix_acl *acl, int type)
@@ -1094,12 +1131,10 @@ int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (error)
 		goto out_inode_unlock;
 
-	if (inode->i_opflags & IOP_XATTR)
+	if (likely(!is_bad_inode(inode)))
 		error = set_posix_acl(idmap, dentry, acl_type, kacl);
-	else if (unlikely(is_bad_inode(inode)))
-		error = -EIO;
 	else
-		error = -EOPNOTSUPP;
+		error = -EIO;
 	if (!error) {
 		fsnotify_xattr(dentry);
 		evm_inode_post_set_acl(dentry, acl_name, kacl);
@@ -1204,12 +1239,10 @@ int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 	if (error)
 		goto out_inode_unlock;
 
-	if (inode->i_opflags & IOP_XATTR)
+	if (likely(!is_bad_inode(inode)))
 		error = set_posix_acl(idmap, dentry, acl_type, NULL);
-	else if (unlikely(is_bad_inode(inode)))
-		error = -EIO;
 	else
-		error = -EOPNOTSUPP;
+		error = -EIO;
 	if (!error) {
 		fsnotify_xattr(dentry);
 		evm_inode_post_remove_acl(idmap, dentry, acl_name);

fs/reiserfs/file.c

@@ -261,3 +261,10 @@ const struct inode_operations reiserfs_file_inode_operations = {
 	.fileattr_get = reiserfs_fileattr_get,
 	.fileattr_set = reiserfs_fileattr_set,
 };
+
+const struct inode_operations reiserfs_priv_file_inode_operations = {
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+	.fileattr_get = reiserfs_fileattr_get,
+	.fileattr_set = reiserfs_fileattr_set,
+};

fs/reiserfs/inode.c

@@ -2087,10 +2087,8 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th,
 	 * Mark it private if we're creating the privroot
 	 * or something under it.
 	 */
-	if (IS_PRIVATE(dir) || dentry == REISERFS_SB(sb)->priv_root) {
-		inode->i_flags |= S_PRIVATE;
-		inode->i_opflags &= ~IOP_XATTR;
-	}
+	if (IS_PRIVATE(dir) || dentry == REISERFS_SB(sb)->priv_root)
+		reiserfs_init_priv_inode(inode);
 
 	if (reiserfs_posixacl(inode->i_sb)) {
 		reiserfs_write_unlock(inode->i_sb);

fs/reiserfs/namei.c

@@ -378,13 +378,11 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
 
 		/*
 		 * Propagate the private flag so we know we're
-		 * in the priv tree.  Also clear IOP_XATTR
+		 * in the priv tree.  Also clear xattr support
 		 * since we don't have xattrs on xattr files.
 		 */
-		if (IS_PRIVATE(dir)) {
-			inode->i_flags |= S_PRIVATE;
-			inode->i_opflags &= ~IOP_XATTR;
-		}
+		if (IS_PRIVATE(dir))
+			reiserfs_init_priv_inode(inode);
 	}
 	reiserfs_write_unlock(dir->i_sb);
 	if (retval == IO_ERROR) {
@@ -1649,6 +1647,48 @@ static int reiserfs_rename(struct mnt_idmap *idmap,
 	return retval;
 }
 
+static const struct inode_operations reiserfs_priv_dir_inode_operations = {
+	.create = reiserfs_create,
+	.lookup = reiserfs_lookup,
+	.link = reiserfs_link,
+	.unlink = reiserfs_unlink,
+	.symlink = reiserfs_symlink,
+	.mkdir = reiserfs_mkdir,
+	.rmdir = reiserfs_rmdir,
+	.mknod = reiserfs_mknod,
+	.rename = reiserfs_rename,
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+	.fileattr_get = reiserfs_fileattr_get,
+	.fileattr_set = reiserfs_fileattr_set,
+};
+
+static const struct inode_operations reiserfs_priv_symlink_inode_operations = {
+	.get_link	= page_get_link,
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+};
+
+static const struct inode_operations reiserfs_priv_special_inode_operations = {
+	.setattr = reiserfs_setattr,
+	.permission = reiserfs_permission,
+};
+
+void reiserfs_init_priv_inode(struct inode *inode)
+{
+	inode->i_flags |= S_PRIVATE;
+	inode->i_opflags &= ~IOP_XATTR;
+
+	if (S_ISREG(inode->i_mode))
+		inode->i_op = &reiserfs_priv_file_inode_operations;
+	else if (S_ISDIR(inode->i_mode))
+		inode->i_op = &reiserfs_priv_dir_inode_operations;
+	else if (S_ISLNK(inode->i_mode))
+		inode->i_op = &reiserfs_priv_symlink_inode_operations;
+	else
+		inode->i_op = &reiserfs_priv_special_inode_operations;
+}
+
 /* directories can handle most operations...  */
 const struct inode_operations reiserfs_dir_inode_operations = {
 	.create = reiserfs_create,

fs/reiserfs/reiserfs.h

@@ -3106,6 +3106,7 @@ int reiserfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len);
 
 /* namei.c */
+void reiserfs_init_priv_inode(struct inode *inode);
 void set_de_name_and_namelen(struct reiserfs_dir_entry *de);
 int search_by_entry_key(struct super_block *sb, const struct cpu_key *key,
 			struct treepath *path, struct reiserfs_dir_entry *de);
@@ -3175,6 +3176,7 @@ void reiserfs_unmap_buffer(struct buffer_head *);
 
 /* file.c */
 extern const struct inode_operations reiserfs_file_inode_operations;
+extern const struct inode_operations reiserfs_priv_file_inode_operations;
 extern const struct file_operations reiserfs_file_operations;
 extern const struct address_space_operations reiserfs_address_space_operations;
 

fs/reiserfs/xattr.c

@@ -52,6 +52,7 @@
 #include <linux/quotaops.h>
 #include <linux/security.h>
 #include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
 
 #define PRIVROOT_NAME ".reiserfs_priv"
 #define XAROOT_NAME   "xattrs"
@@ -770,23 +771,34 @@ reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
 			(handler) != NULL;			\
 			(handler) = *(handlers)++)
 
+static inline bool reiserfs_posix_acl_list(const char *name,
+					   struct dentry *dentry)
+{
+	return (posix_acl_type(name) >= 0) &&
+	       IS_POSIXACL(d_backing_inode(dentry));
+}
+
 /* This is the implementation for the xattr plugin infrastructure */
-static inline const struct xattr_handler *
-find_xattr_handler_prefix(const struct xattr_handler **handlers,
-			   const char *name)
+static inline bool reiserfs_xattr_list(const struct xattr_handler **handlers,
+				       const char *name, struct dentry *dentry)
 {
-	const struct xattr_handler *xah;
+	if (handlers) {
+		const struct xattr_handler *xah = NULL;
 
-	if (!handlers)
-		return NULL;
+		for_each_xattr_handler(handlers, xah) {
+			const char *prefix = xattr_prefix(xah);
 
-	for_each_xattr_handler(handlers, xah) {
-		const char *prefix = xattr_prefix(xah);
-		if (strncmp(prefix, name, strlen(prefix)) == 0)
-			break;
+			if (strncmp(prefix, name, strlen(prefix)))
+				continue;
+
+			if (!xattr_handler_can_list(xah, dentry))
+				return false;
+
+			return true;
+		}
 	}
 
-	return xah;
+	return reiserfs_posix_acl_list(name, dentry);
 }
 
 struct listxattr_buf {
@@ -807,12 +819,8 @@ static bool listxattr_filler(struct dir_context *ctx, const char *name,
 
 	if (name[0] != '.' ||
 	    (namelen != 1 && (name[1] != '.' || namelen != 2))) {
-		const struct xattr_handler *handler;
-
-		handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
-						    name);
-		if (!handler /* Unsupported xattr name */ ||
-		    (handler->list && !handler->list(b->dentry)))
+		if (!reiserfs_xattr_list(b->dentry->d_sb->s_xattr, name,
+					 b->dentry))
 			return true;
 		size = namelen + 1;
 		if (b->buf) {
@@ -888,8 +896,7 @@ static int create_privroot(struct dentry *dentry)
 		return -EOPNOTSUPP;
 	}
 
-	d_inode(dentry)->i_flags |= S_PRIVATE;
-	d_inode(dentry)->i_opflags &= ~IOP_XATTR;
+	reiserfs_init_priv_inode(d_inode(dentry));
 	reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
 		      "storage.\n", PRIVROOT_NAME);
 
@@ -910,10 +917,6 @@ const struct xattr_handler *reiserfs_xattr_handlers[] = {
 #endif
 #ifdef CONFIG_REISERFS_FS_SECURITY
 	&reiserfs_xattr_security_handler,
-#endif
-#ifdef CONFIG_REISERFS_FS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
 #endif
 	NULL
 };
@@ -975,10 +978,8 @@ int reiserfs_lookup_privroot(struct super_block *s)
 	if (!IS_ERR(dentry)) {
 		REISERFS_SB(s)->priv_root = dentry;
 		d_set_d_op(dentry, &xattr_lookup_poison_ops);
-		if (d_really_is_positive(dentry)) {
-			d_inode(dentry)->i_flags |= S_PRIVATE;
-			d_inode(dentry)->i_opflags &= ~IOP_XATTR;
-		}
+		if (d_really_is_positive(dentry))
+			reiserfs_init_priv_inode(d_inode(dentry));
 	} else
 		err = PTR_ERR(dentry);
 	inode_unlock(d_inode(s->s_root));

fs/xattr.c

@@ -160,11 +160,10 @@ xattr_permission(struct mnt_idmap *idmap, struct inode *inode,
  * Look for any handler that deals with the specified namespace.
  */
 int
-xattr_supported_namespace(struct inode *inode, const char *prefix)
+xattr_supports_user_prefix(struct inode *inode)
 {
 	const struct xattr_handler **handlers = inode->i_sb->s_xattr;
 	const struct xattr_handler *handler;
-	size_t preflen;
 
 	if (!(inode->i_opflags & IOP_XATTR)) {
 		if (unlikely(is_bad_inode(inode)))
@@ -172,16 +171,15 @@ xattr_supported_namespace(struct inode *inode, const char *prefix)
 		return -EOPNOTSUPP;
 	}
 
-	preflen = strlen(prefix);
-
 	for_each_xattr_handler(handlers, handler) {
-		if (!strncmp(xattr_prefix(handler), prefix, preflen))
+		if (!strncmp(xattr_prefix(handler), XATTR_USER_PREFIX,
+			     XATTR_USER_PREFIX_LEN))
 			return 0;
 	}
 
 	return -EOPNOTSUPP;
 }
-EXPORT_SYMBOL(xattr_supported_namespace);
+EXPORT_SYMBOL(xattr_supports_user_prefix);
 
 int
 __vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
@@ -460,6 +458,28 @@ vfs_getxattr(struct mnt_idmap *idmap, struct dentry *dentry,
 }
 EXPORT_SYMBOL_GPL(vfs_getxattr);
 
+/**
+ * vfs_listxattr - retrieve \0 separated list of xattr names
+ * @dentry: the dentry from whose inode the xattr names are retrieved
+ * @list: buffer to store xattr names into
+ * @size: size of the buffer
+ *
+ * This function returns the names of all xattrs associated with the
+ * inode of @dentry.
+ *
+ * Note, for legacy reasons the vfs_listxattr() function lists POSIX
+ * ACLs as well. Since POSIX ACLs are decoupled from IOP_XATTR the
+ * vfs_listxattr() function doesn't check for this flag since a
+ * filesystem could implement POSIX ACLs without implementing any other
+ * xattrs.
+ *
+ * However, since all codepaths that remove IOP_XATTR also assign of
+ * inode operations that either don't implement or implement a stub
+ * ->listxattr() operation.
+ *
+ * Return: On success, the size of the buffer that was used. On error a
+ *         negative error code.
+ */
 ssize_t
 vfs_listxattr(struct dentry *dentry, char *list, size_t size)
 {
@@ -469,7 +489,8 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size)
 	error = security_inode_listxattr(dentry);
 	if (error)
 		return error;
-	if (inode->i_op->listxattr && (inode->i_opflags & IOP_XATTR)) {
+
+	if (inode->i_op->listxattr) {
 		error = inode->i_op->listxattr(dentry, list, size);
 	} else {
 		error = security_inode_listsecurity(inode, list, size);
@@ -949,6 +970,21 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
 	return error;
 }
 
+int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name)
+{
+	size_t len;
+
+	len = strlen(name) + 1;
+	if (*buffer) {
+		if (*remaining_size < len)
+			return -ERANGE;
+		memcpy(*buffer, name, len);
+		*buffer += len;
+	}
+	*remaining_size -= len;
+	return 0;
+}
+
 /*
  * Combine the results of the list() operation from every xattr_handler in the
  * list.
@@ -957,33 +993,22 @@ ssize_t
 generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 {
 	const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;
-	unsigned int size = 0;
-
-	if (!buffer) {
-		for_each_xattr_handler(handlers, handler) {
-			if (!handler->name ||
-			    (handler->list && !handler->list(dentry)))
-				continue;
-			size += strlen(handler->name) + 1;
-		}
-	} else {
-		char *buf = buffer;
-		size_t len;
-
-		for_each_xattr_handler(handlers, handler) {
-			if (!handler->name ||
-			    (handler->list && !handler->list(dentry)))
-				continue;
-			len = strlen(handler->name);
-			if (len + 1 > buffer_size)
-				return -ERANGE;
-			memcpy(buf, handler->name, len + 1);
-			buf += len + 1;
-			buffer_size -= len + 1;
-		}
-		size = buf - buffer;
+	ssize_t remaining_size = buffer_size;
+	int err = 0;
+
+	err = posix_acl_listxattr(d_inode(dentry), &buffer, &remaining_size);
+	if (err)
+		return err;
+
+	for_each_xattr_handler(handlers, handler) {
+		if (!handler->name || (handler->list && !handler->list(dentry)))
+			continue;
+		err = xattr_list_one(&buffer, &remaining_size, handler->name);
+		if (err)
+			return err;
 	}
-	return size;
+
+	return err ? err : buffer_size - remaining_size;
 }
 EXPORT_SYMBOL(generic_listxattr);
 
@@ -1245,20 +1270,6 @@ static bool xattr_is_trusted(const char *name)
 	return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
 }
 
-static int xattr_list_one(char **buffer, ssize_t *remaining_size,
-			  const char *name)
-{
-	size_t len = strlen(name) + 1;
-	if (*buffer) {
-		if (*remaining_size < len)
-			return -ERANGE;
-		memcpy(*buffer, name, len);
-		*buffer += len;
-	}
-	*remaining_size -= len;
-	return 0;
-}
-
 /**
  * simple_xattr_list - list all xattr objects
  * @inode: inode from which to get the xattrs
@@ -1287,22 +1298,9 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 	ssize_t remaining_size = size;
 	int err = 0;
 
-#ifdef CONFIG_FS_POSIX_ACL
-	if (IS_POSIXACL(inode)) {
-		if (inode->i_acl) {
-			err = xattr_list_one(&buffer, &remaining_size,
-					     XATTR_NAME_POSIX_ACL_ACCESS);
-			if (err)
-				return err;
-		}
-		if (inode->i_default_acl) {
-			err = xattr_list_one(&buffer, &remaining_size,
-					     XATTR_NAME_POSIX_ACL_DEFAULT);
-			if (err)
-				return err;
-		}
-	}
-#endif
+	err = posix_acl_listxattr(inode, &buffer, &remaining_size);
+	if (err)
+		return err;
 
 	read_lock(&xattrs->lock);
 	for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) {

fs/xfs/xfs_xattr.c

@@ -179,10 +179,6 @@ const struct xattr_handler *xfs_xattr_handlers[] = {
 	&xfs_xattr_user_handler,
 	&xfs_xattr_trusted_handler,
 	&xfs_xattr_security_handler,
-#ifdef CONFIG_XFS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	NULL
 };
 

include/linux/posix_acl.h

@@ -106,6 +106,8 @@ struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 			      struct dentry *dentry, const char *acl_name);
 int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 		   const char *acl_name);
+int posix_acl_listxattr(struct inode *inode, char **buffer,
+			ssize_t *remaining_size);
 #else
 static inline int posix_acl_chmod(struct mnt_idmap *idmap,
 				  struct dentry *dentry, umode_t mode)
@@ -153,6 +155,11 @@ static inline int vfs_remove_acl(struct mnt_idmap *idmap,
 {
 	return -EOPNOTSUPP;
 }
+static inline int posix_acl_listxattr(struct inode *inode, char **buffer,
+				      ssize_t *remaining_size)
+{
+	return 0;
+}
 #endif /* CONFIG_FS_POSIX_ACL */
 
 struct posix_acl *get_inode_acl(struct inode *inode, int type);

include/linux/posix_acl_xattr.h

@@ -68,7 +68,8 @@ static inline int posix_acl_type(const char *name)
 	return -1;
 }
 
-extern const struct xattr_handler posix_acl_access_xattr_handler;
-extern const struct xattr_handler posix_acl_default_xattr_handler;
+/* These are legacy handlers. Don't use them for new code. */
+extern const struct xattr_handler nop_posix_acl_access;
+extern const struct xattr_handler nop_posix_acl_default;
 
 #endif	/* _POSIX_ACL_XATTR_H */

include/linux/xattr.h

@@ -47,6 +47,22 @@ struct xattr_handler {
 		   size_t size, int flags);
 };
 
+/**
+ * xattr_handler_can_list - check whether xattr can be listed
+ * @handler: handler for this type of xattr
+ * @dentry: dentry whose inode xattr to list
+ *
+ * Determine whether the xattr associated with @dentry can be listed given
+ * @handler.
+ *
+ * Return: true if xattr can be listed, false if not.
+ */
+static inline bool xattr_handler_can_list(const struct xattr_handler *handler,
+					  struct dentry *dentry)
+{
+	return handler && (!handler->list || handler->list(dentry));
+}
+
 const char *xattr_full_name(const struct xattr_handler *, const char *);
 
 struct xattr {
@@ -78,7 +94,7 @@ int vfs_getxattr_alloc(struct mnt_idmap *idmap,
 		       struct dentry *dentry, const char *name,
 		       char **xattr_value, size_t size, gfp_t flags);
 
-int xattr_supported_namespace(struct inode *inode, const char *prefix);
+int xattr_supports_user_prefix(struct inode *inode);
 
 static inline const char *xattr_prefix(const struct xattr_handler *handler)
 {
@@ -109,5 +125,6 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 			  char *buffer, size_t size);
 void simple_xattr_add(struct simple_xattrs *xattrs,
 		      struct simple_xattr *new_xattr);
+int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name);
 
 #endif	/* _LINUX_XATTR_H */

mm/shmem.c

@@ -3339,10 +3339,6 @@ static const struct xattr_handler shmem_trusted_xattr_handler = {
 };
 
 static const struct xattr_handler *shmem_xattr_handlers[] = {
-#ifdef CONFIG_TMPFS_POSIX_ACL
-	&posix_acl_access_xattr_handler,
-	&posix_acl_default_xattr_handler,
-#endif
 	&shmem_security_xattr_handler,
 	&shmem_trusted_xattr_handler,
 	NULL