From 97d79299223baab330b194437e676d301f12d5f6 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Wed, 2 Dec 2015 14:44:35 +0100
Subject: posix acls: Remove duplicate xattr name definitions

Remove POSIX_ACL_XATTR_{ACCESS,DEFAULT} and GFS2_POSIX_ACL_{ACCESS,DEFAULT}
and replace them with the definitions in <include/uapi/linux/xattr.h>.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/nfs3acl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
index 1ebe2fc7cda2..17c0fa1eccfa 100644
--- a/fs/nfs/nfs3acl.c
+++ b/fs/nfs/nfs3acl.c
@@ -284,12 +284,12 @@ nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
 	int error;
 
 	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
-			POSIX_ACL_XATTR_ACCESS, data, size, &result);
+			XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
 	if (error)
 		return error;
 
 	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
-			POSIX_ACL_XATTR_DEFAULT, data, size, &result);
+			XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
 	if (error)
 		return error;
 	return result;
-- 
cgit v1.2.3


From 98e9cb5711c68223f0e4d5201b9a6add255ec550 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Wed, 2 Dec 2015 14:44:36 +0100
Subject: vfs: Distinguish between full xattr names and proper prefixes

Add an additional "name" field to struct xattr_handler.  When the name
is set, the handler matches attributes with exactly that name.  When the
prefix is set instead, the handler matches attributes with the given
prefix and with a non-empty suffix.

This patch should avoid bugs like the one fixed in commit c361016a in
the future.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/9p/acl.c              | 16 +++++-----------
 fs/9p/xattr.c            |  4 ----
 fs/ext2/xattr_security.c |  4 ----
 fs/ext2/xattr_trusted.c  |  4 ----
 fs/ext2/xattr_user.c     |  4 ----
 fs/ext4/xattr_security.c |  4 ----
 fs/ext4/xattr_trusted.c  |  4 ----
 fs/ext4/xattr_user.c     |  4 ----
 fs/f2fs/xattr.c          | 20 ++++++--------------
 fs/f2fs/xattr.h          |  2 +-
 fs/hfsplus/xattr.c       | 12 ------------
 fs/jffs2/security.c      |  6 ------
 fs/jffs2/xattr_trusted.c |  4 ----
 fs/jffs2/xattr_user.c    |  4 ----
 fs/nfs/nfs4proc.c        |  8 +-------
 fs/ocfs2/xattr.c         | 17 +----------------
 fs/posix_acl.c           | 10 +++-------
 fs/reiserfs/xattr.c      |  3 ++-
 fs/squashfs/xattr.c      |  3 ---
 fs/xattr.c               | 27 +++++++++++++++++----------
 fs/xfs/xfs_xattr.c       |  6 ------
 include/linux/xattr.h    | 11 +++++++++++
 22 files changed, 47 insertions(+), 130 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 6ff30b14bc76..9da967f38387 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -220,15 +220,12 @@ static int v9fs_xattr_get_acl(const struct xattr_handler *handler,
 	struct posix_acl *acl;
 	int error;
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	v9ses = v9fs_dentry2v9ses(dentry);
 	/*
 	 * We allow set/get/list of acl when access=client is not specified
 	 */
 	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
-		return v9fs_xattr_get(dentry, handler->prefix, buffer, size);
+		return v9fs_xattr_get(dentry, handler->name, buffer, size);
 
 	acl = v9fs_get_cached_acl(d_inode(dentry), handler->flags);
 	if (IS_ERR(acl))
@@ -250,16 +247,13 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
 	struct v9fs_session_info *v9ses;
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	v9ses = v9fs_dentry2v9ses(dentry);
 	/*
 	 * set the attribute on the remote. Without even looking at the
 	 * xattr value. We leave it to the server to validate
 	 */
 	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
-		return v9fs_xattr_set(dentry, handler->prefix, value, size,
+		return v9fs_xattr_set(dentry, handler->name, value, size,
 				      flags);
 
 	if (S_ISLNK(inode->i_mode))
@@ -319,7 +313,7 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
 	default:
 		BUG();
 	}
-	retval = v9fs_xattr_set(dentry, handler->prefix, value, size, flags);
+	retval = v9fs_xattr_set(dentry, handler->name, value, size, flags);
 	if (!retval)
 		set_cached_acl(inode, handler->flags, acl);
 err_out:
@@ -328,14 +322,14 @@ err_out:
 }
 
 const struct xattr_handler v9fs_xattr_acl_access_handler = {
-	.prefix	= XATTR_NAME_POSIX_ACL_ACCESS,
+	.name	= XATTR_NAME_POSIX_ACL_ACCESS,
 	.flags	= ACL_TYPE_ACCESS,
 	.get	= v9fs_xattr_get_acl,
 	.set	= v9fs_xattr_set_acl,
 };
 
 const struct xattr_handler v9fs_xattr_acl_default_handler = {
-	.prefix	= XATTR_NAME_POSIX_ACL_DEFAULT,
+	.name	= XATTR_NAME_POSIX_ACL_DEFAULT,
 	.flags	= ACL_TYPE_DEFAULT,
 	.get	= v9fs_xattr_get_acl,
 	.set	= v9fs_xattr_set_acl,
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index e3d026ac382e..9dd9b47a6c1a 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -143,8 +143,6 @@ static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
 {
 	const char *full_name = xattr_full_name(handler, name);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return v9fs_xattr_get(dentry, full_name, buffer, size);
 }
 
@@ -154,8 +152,6 @@ static int v9fs_xattr_handler_set(const struct xattr_handler *handler,
 {
 	const char *full_name = xattr_full_name(handler, name);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return v9fs_xattr_set(dentry, full_name, value, size, flags);
 }
 
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index dfb08750370d..118bf231bc7f 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -28,8 +28,6 @@ ext2_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
 			      buffer, size);
 }
@@ -39,8 +37,6 @@ ext2_xattr_security_set(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
 			      value, size, flags);
 }
diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
index 3150dd3a7859..3f8f2bc6539e 100644
--- a/fs/ext2/xattr_trusted.c
+++ b/fs/ext2/xattr_trusted.c
@@ -32,8 +32,6 @@ ext2_xattr_trusted_get(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
 			      buffer, size);
 }
@@ -43,8 +41,6 @@ ext2_xattr_trusted_set(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
 			      value, size, flags);
 }
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
index 339a49bbb8ef..afd45ab1218c 100644
--- a/fs/ext2/xattr_user.c
+++ b/fs/ext2/xattr_user.c
@@ -34,8 +34,6 @@ ext2_xattr_user_get(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_USER,
@@ -47,8 +45,6 @@ ext2_xattr_user_set(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 36f4c1a84c21..195abc4a88bb 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -33,8 +33,6 @@ ext4_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY,
 			      name, buffer, size);
 }
@@ -44,8 +42,6 @@ ext4_xattr_security_set(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY,
 			      name, value, size, flags);
 }
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index 488089053342..121fdf9fdc02 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -36,8 +36,6 @@ ext4_xattr_trusted_get(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name, void *buffer,
 		       size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
 			      name, buffer, size);
 }
@@ -47,8 +45,6 @@ ext4_xattr_trusted_set(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
 			      name, value, size, flags);
 }
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index d2dec3364062..577fc122d884 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -35,8 +35,6 @@ ext4_xattr_user_get(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_USER,
@@ -48,8 +46,6 @@ ext4_xattr_user_set(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_USER,
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 862368a32e53..21cfe516034f 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -30,6 +30,7 @@ static size_t f2fs_xattr_generic_list(const struct xattr_handler *handler,
 		const char *name, size_t len)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	const char *prefix;
 	int total_len, prefix_len;
 
 	switch (handler->flags) {
@@ -47,10 +48,11 @@ static size_t f2fs_xattr_generic_list(const struct xattr_handler *handler,
 		return -EINVAL;
 	}
 
-	prefix_len = strlen(handler->prefix);
+	prefix = xattr_prefix(handler);
+	prefix_len = strlen(prefix);
 	total_len = prefix_len + len + 1;
 	if (list && total_len <= list_size) {
-		memcpy(list, handler->prefix, prefix_len);
+		memcpy(list, prefix, prefix_len);
 		memcpy(list + prefix_len, name, len);
 		list[prefix_len + len] = '\0';
 	}
@@ -77,8 +79,6 @@ static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
 	default:
 		return -EINVAL;
 	}
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return f2fs_getxattr(d_inode(dentry), handler->flags, name,
 			     buffer, size, NULL);
 }
@@ -103,9 +103,6 @@ static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
 	default:
 		return -EINVAL;
 	}
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	return f2fs_setxattr(d_inode(dentry), handler->flags, name,
 					value, size, NULL, flags);
 }
@@ -114,7 +111,7 @@ static size_t f2fs_xattr_advise_list(const struct xattr_handler *handler,
 		struct dentry *dentry, char *list, size_t list_size,
 		const char *name, size_t len)
 {
-	const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
+	const char *xname = F2FS_SYSTEM_ADVISE_NAME;
 	size_t size;
 
 	size = strlen(xname) + 1;
@@ -129,9 +126,6 @@ static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
 {
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	if (buffer)
 		*((char *)buffer) = F2FS_I(inode)->i_advise;
 	return sizeof(char);
@@ -143,8 +137,6 @@ static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
 {
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;
 	if (value == NULL)
@@ -197,7 +189,7 @@ const struct xattr_handler f2fs_xattr_trusted_handler = {
 };
 
 const struct xattr_handler f2fs_xattr_advise_handler = {
-	.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
+	.name	= F2FS_SYSTEM_ADVISE_NAME,
 	.flags	= F2FS_XATTR_INDEX_ADVISE,
 	.list   = f2fs_xattr_advise_list,
 	.get    = f2fs_xattr_advise_get,
diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h
index 71a7100d5492..79dccc8252dd 100644
--- a/fs/f2fs/xattr.h
+++ b/fs/f2fs/xattr.h
@@ -27,7 +27,7 @@
 #define F2FS_XATTR_REFCOUNT_MAX         1024
 
 /* Name indexes */
-#define F2FS_SYSTEM_ADVISE_PREFIX		"system.advise"
+#define F2FS_SYSTEM_ADVISE_NAME			"system.advise"
 #define F2FS_XATTR_INDEX_USER			1
 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index e41a010cd89c..ab01530b4930 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -431,9 +431,6 @@ int hfsplus_setxattr(struct dentry *dentry, const char *name,
 	char *xattr_name;
 	int res;
 
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 		GFP_KERNEL);
 	if (!xattr_name)
@@ -589,9 +586,6 @@ ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
 	int res;
 	char *xattr_name;
 
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 			     GFP_KERNEL);
 	if (!xattr_name)
@@ -853,9 +847,6 @@ static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 				struct dentry *dentry, const char *name,
 				void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	/*
 	 * Don't allow retrieving properly prefixed attributes
 	 * by prepending them with "osx."
@@ -876,9 +867,6 @@ static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
 				struct dentry *dentry, const char *name,
 				const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	/*
 	 * Don't allow setting properly prefixed attributes
 	 * by prepending them with "osx."
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index bf12fe5f83d7..ea79932cd665 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -52,9 +52,6 @@ static int jffs2_security_getxattr(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_SECURITY,
 				 name, buffer, size);
 }
@@ -63,9 +60,6 @@ static int jffs2_security_setxattr(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_SECURITY,
 				 name, buffer, size, flags);
 }
diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c
index a562da0d6a26..8b55fe44c777 100644
--- a/fs/jffs2/xattr_trusted.c
+++ b/fs/jffs2/xattr_trusted.c
@@ -20,8 +20,6 @@ static int jffs2_trusted_getxattr(const struct xattr_handler *handler,
 				  struct dentry *dentry, const char *name,
 				  void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_TRUSTED,
 				 name, buffer, size);
 }
@@ -30,8 +28,6 @@ static int jffs2_trusted_setxattr(const struct xattr_handler *handler,
 				  struct dentry *dentry, const char *name,
 				  const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_TRUSTED,
 				 name, buffer, size, flags);
 }
diff --git a/fs/jffs2/xattr_user.c b/fs/jffs2/xattr_user.c
index cbc0472e59a8..b04335b84833 100644
--- a/fs/jffs2/xattr_user.c
+++ b/fs/jffs2/xattr_user.c
@@ -20,8 +20,6 @@ static int jffs2_user_getxattr(const struct xattr_handler *handler,
 			       struct dentry *dentry, const char *name,
 			       void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_USER,
 				 name, buffer, size);
 }
@@ -30,8 +28,6 @@ static int jffs2_user_setxattr(const struct xattr_handler *handler,
 			       struct dentry *dentry, const char *name,
 			       const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_USER,
 				 name, buffer, size, flags);
 }
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 89818036f035..f6f40aae92b1 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6253,9 +6253,6 @@ static int nfs4_xattr_set_nfs4_acl(const struct xattr_handler *handler,
 				   const void *buf, size_t buflen,
 				   int flags)
 {
-	if (strcmp(key, "") != 0)
-		return -EINVAL;
-
 	return nfs4_proc_set_acl(d_inode(dentry), buf, buflen);
 }
 
@@ -6263,9 +6260,6 @@ static int nfs4_xattr_get_nfs4_acl(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *key,
 				   void *buf, size_t buflen)
 {
-	if (strcmp(key, "") != 0)
-		return -EINVAL;
-
 	return nfs4_proc_get_acl(d_inode(dentry), buf, buflen);
 }
 
@@ -8834,7 +8828,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
 };
 
 static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
-	.prefix	= XATTR_NAME_NFSV4_ACL,
+	.name	= XATTR_NAME_NFSV4_ACL,
 	.list	= nfs4_xattr_list_nfs4_acl,
 	.get	= nfs4_xattr_get_nfs4_acl,
 	.set	= nfs4_xattr_set_nfs4_acl,
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index e9164f09841b..5823f985a662 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -544,8 +544,7 @@ static inline const char *ocfs2_xattr_prefix(int name_index)
 
 	if (name_index > 0 && name_index < OCFS2_XATTR_MAX)
 		handler = ocfs2_xattr_handler_map[name_index];
-
-	return handler ? handler->prefix : NULL;
+	return handler ? xattr_prefix(handler) : NULL;
 }
 
 static u32 ocfs2_xattr_name_hash(struct inode *inode,
@@ -7249,8 +7248,6 @@ static int ocfs2_xattr_security_get(const struct xattr_handler *handler,
 				    struct dentry *dentry, const char *name,
 				    void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ocfs2_xattr_get(d_inode(dentry), OCFS2_XATTR_INDEX_SECURITY,
 			       name, buffer, size);
 }
@@ -7259,9 +7256,6 @@ static int ocfs2_xattr_security_set(const struct xattr_handler *handler,
 				    struct dentry *dentry, const char *name,
 				    const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	return ocfs2_xattr_set(d_inode(dentry), OCFS2_XATTR_INDEX_SECURITY,
 			       name, value, size, flags);
 }
@@ -7345,8 +7339,6 @@ static int ocfs2_xattr_trusted_get(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ocfs2_xattr_get(d_inode(dentry), OCFS2_XATTR_INDEX_TRUSTED,
 			       name, buffer, size);
 }
@@ -7355,9 +7347,6 @@ static int ocfs2_xattr_trusted_set(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	return ocfs2_xattr_set(d_inode(dentry), OCFS2_XATTR_INDEX_TRUSTED,
 			       name, value, size, flags);
 }
@@ -7398,8 +7387,6 @@ static int ocfs2_xattr_user_get(const struct xattr_handler *handler,
 {
 	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
 		return -EOPNOTSUPP;
 	return ocfs2_xattr_get(d_inode(dentry), OCFS2_XATTR_INDEX_USER, name,
@@ -7412,8 +7399,6 @@ static int ocfs2_xattr_user_set(const struct xattr_handler *handler,
 {
 	struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
 		return -EOPNOTSUPP;
 
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 571465d6df58..17efd76978c8 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -769,8 +769,6 @@ posix_acl_xattr_get(const struct xattr_handler *handler,
 	struct posix_acl *acl;
 	int error;
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
 	if (!IS_POSIXACL(d_backing_inode(dentry)))
 		return -EOPNOTSUPP;
 	if (d_is_symlink(dentry))
@@ -797,8 +795,6 @@ posix_acl_xattr_set(const struct xattr_handler *handler,
 	struct posix_acl *acl = NULL;
 	int ret;
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
 	if (!IS_POSIXACL(inode))
 		return -EOPNOTSUPP;
 	if (!inode->i_op->set_acl)
@@ -832,7 +828,7 @@ posix_acl_xattr_list(const struct xattr_handler *handler,
 		     struct dentry *dentry, char *list, size_t list_size,
 		     const char *name, size_t name_len)
 {
-	const char *xname = handler->prefix;
+	const char *xname = handler->name;
 	size_t size;
 
 	if (!IS_POSIXACL(d_backing_inode(dentry)))
@@ -845,7 +841,7 @@ posix_acl_xattr_list(const struct xattr_handler *handler,
 }
 
 const struct xattr_handler posix_acl_access_xattr_handler = {
-	.prefix = XATTR_NAME_POSIX_ACL_ACCESS,
+	.name = XATTR_NAME_POSIX_ACL_ACCESS,
 	.flags = ACL_TYPE_ACCESS,
 	.list = posix_acl_xattr_list,
 	.get = posix_acl_xattr_get,
@@ -854,7 +850,7 @@ const struct xattr_handler posix_acl_access_xattr_handler = {
 EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
 
 const struct xattr_handler posix_acl_default_xattr_handler = {
-	.prefix = XATTR_NAME_POSIX_ACL_DEFAULT,
+	.name = XATTR_NAME_POSIX_ACL_DEFAULT,
 	.flags = ACL_TYPE_DEFAULT,
 	.list = posix_acl_xattr_list,
 	.get = posix_acl_xattr_get,
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 66b26fdfff8d..efe2ed3c13c5 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -756,7 +756,8 @@ find_xattr_handler_prefix(const struct xattr_handler **handlers,
 		return NULL;
 
 	for_each_xattr_handler(handlers, xah) {
-		if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
+		const char *prefix = xattr_prefix(xah);
+		if (strncmp(prefix, name, strlen(prefix)) == 0)
 			break;
 	}
 
diff --git a/fs/squashfs/xattr.c b/fs/squashfs/xattr.c
index 6a4cc344085c..2f0ccbaa2d92 100644
--- a/fs/squashfs/xattr.c
+++ b/fs/squashfs/xattr.c
@@ -228,9 +228,6 @@ static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
 				      struct dentry *d, const char *name,
 				      void *buffer, size_t size)
 {
-	if (name[0] == '\0')
-		return  -EINVAL;
-
 	return squashfs_xattr_get(d_inode(d), handler->flags, name,
 		buffer, size);
 }
diff --git a/fs/xattr.c b/fs/xattr.c
index 58bdabcc9d35..418ad691cf4e 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -681,13 +681,20 @@ xattr_resolve_name(const struct xattr_handler **handlers, const char **name)
 		return NULL;
 
 	for_each_xattr_handler(handlers, handler) {
-		const char *n = strcmp_prefix(*name, handler->prefix);
+		const char *n;
+
+		n = strcmp_prefix(*name, xattr_prefix(handler));
 		if (n) {
+			if (!handler->prefix ^ !*n) {
+				if (*n)
+					continue;
+				return ERR_PTR(-EINVAL);
+			}
 			*name = n;
-			break;
+			return handler;
 		}
 	}
-	return handler;
+	return ERR_PTR(-EOPNOTSUPP);
 }
 
 /*
@@ -699,8 +706,8 @@ generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t s
 	const struct xattr_handler *handler;
 
 	handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
-	if (!handler)
-		return -EOPNOTSUPP;
+	if (IS_ERR(handler))
+		return PTR_ERR(handler);
 	return handler->get(handler, dentry, name, buffer, size);
 }
 
@@ -746,8 +753,8 @@ generic_setxattr(struct dentry *dentry, const char *name, const void *value, siz
 	if (size == 0)
 		value = "";  /* empty EA, do not remove */
 	handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
-	if (!handler)
-		return -EOPNOTSUPP;
+	if (IS_ERR(handler))
+		return PTR_ERR(handler);
 	return handler->set(handler, dentry, name, value, size, flags);
 }
 
@@ -761,8 +768,8 @@ generic_removexattr(struct dentry *dentry, const char *name)
 	const struct xattr_handler *handler;
 
 	handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
-	if (!handler)
-		return -EOPNOTSUPP;
+	if (IS_ERR(handler))
+		return PTR_ERR(handler);
 	return handler->set(handler, dentry, name, NULL, 0, XATTR_REPLACE);
 }
 
@@ -789,7 +796,7 @@ EXPORT_SYMBOL(generic_removexattr);
 const char *xattr_full_name(const struct xattr_handler *handler,
 			    const char *name)
 {
-	size_t prefix_len = strlen(handler->prefix);
+	size_t prefix_len = strlen(xattr_prefix(handler));
 
 	return name - prefix_len;
 }
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 7288795718c9..36a43851aac0 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -39,9 +39,6 @@ xfs_xattr_get(const struct xattr_handler *handler, struct dentry *dentry,
 	struct xfs_inode *ip = XFS_I(d_inode(dentry));
 	int error, asize = size;
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	/* Convert Linux syscall to XFS internal ATTR flags */
 	if (!size) {
 		xflags |= ATTR_KERNOVAL;
@@ -84,9 +81,6 @@ xfs_xattr_set(const struct xattr_handler *handler, struct dentry *dentry,
 	struct xfs_inode	*ip = XFS_I(d_inode(dentry));
 	int			error;
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	/* Convert Linux syscall to XFS internal ATTR flags */
 	if (flags & XATTR_CREATE)
 		xflags |= ATTR_CREATE;
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 45fa3456a0cc..03c847fb6cc1 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -19,7 +19,13 @@
 struct inode;
 struct dentry;
 
+/*
+ * struct xattr_handler: When @name is set, match attributes with exactly that
+ * name.  When @prefix is set instead, match attributes with that prefix and
+ * with a non-empty suffix.
+ */
 struct xattr_handler {
+	const char *name;
 	const char *prefix;
 	int flags;      /* fs private flags */
 	size_t (*list)(const struct xattr_handler *, struct dentry *dentry,
@@ -54,6 +60,11 @@ int generic_removexattr(struct dentry *dentry, const char *name);
 ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
 			   char **xattr_value, size_t size, gfp_t flags);
 
+static inline const char *xattr_prefix(const struct xattr_handler *handler)
+{
+	return handler->prefix ?: handler->name;
+}
+
 struct simple_xattrs {
 	struct list_head head;
 	spinlock_t lock;
-- 
cgit v1.2.3


From c4803c497fbdb37e96af614813a7cfb434b6682a Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Wed, 2 Dec 2015 14:44:41 +0100
Subject: nfs: Move call to security_inode_listsecurity into nfs_listxattr

Add a nfs_listxattr operation.  Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/nfs4proc.c          | 53 +++++++++++++++++++++++++++++++---------------
 fs/xattr.c                 |  4 ++++
 security/smack/smack_lsm.c |  2 --
 3 files changed, 40 insertions(+), 19 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f6f40aae92b1..dbfade2602c9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6279,10 +6279,6 @@ static size_t nfs4_xattr_list_nfs4_acl(const struct xattr_handler *handler,
 }
 
 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
-static inline int nfs4_server_supports_labels(struct nfs_server *server)
-{
-	return server->caps & NFS_CAP_SECURITY_LABEL;
-}
 
 static int nfs4_xattr_set_nfs4_label(const struct xattr_handler *handler,
 				     struct dentry *dentry, const char *key,
@@ -6304,29 +6300,34 @@ static int nfs4_xattr_get_nfs4_label(const struct xattr_handler *handler,
 	return -EOPNOTSUPP;
 }
 
-static size_t nfs4_xattr_list_nfs4_label(const struct xattr_handler *handler,
-					 struct dentry *dentry, char *list,
-					 size_t list_len, const char *name,
-					 size_t name_len)
+static ssize_t
+nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len)
 {
-	size_t len = 0;
+	int len = 0;
 
-	if (nfs_server_capable(d_inode(dentry), NFS_CAP_SECURITY_LABEL)) {
-		len = security_inode_listsecurity(d_inode(dentry), NULL, 0);
-		if (list && len <= list_len)
-			security_inode_listsecurity(d_inode(dentry), list, len);
+	if (nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL)) {
+		len = security_inode_listsecurity(inode, list, list_len);
+		if (list_len && len > list_len)
+			return -ERANGE;
 	}
 	return len;
 }
 
 static const struct xattr_handler nfs4_xattr_nfs4_label_handler = {
 	.prefix = XATTR_SECURITY_PREFIX,
-	.list	= nfs4_xattr_list_nfs4_label,
 	.get	= nfs4_xattr_get_nfs4_label,
 	.set	= nfs4_xattr_set_nfs4_label,
 };
-#endif
 
+#else
+
+static ssize_t
+nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len)
+{
+	return 0;
+}
+
+#endif
 
 /*
  * nfs_fhget will use either the mounted_on_fileid or the fileid
@@ -8743,6 +8744,24 @@ const struct nfs4_minor_version_ops *nfs_v4_minor_ops[] = {
 #endif
 };
 
+ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size)
+{
+	ssize_t error, error2;
+
+	error = generic_listxattr(dentry, list, size);
+	if (error < 0)
+		return error;
+	if (list) {
+		list += error;
+		size -= error;
+	}
+
+	error2 = nfs4_listxattr_nfs4_label(d_inode(dentry), list, size);
+	if (error2 < 0)
+		return error2;
+	return error + error2;
+}
+
 static const struct inode_operations nfs4_dir_inode_operations = {
 	.create		= nfs_create,
 	.lookup		= nfs_lookup,
@@ -8759,7 +8778,7 @@ static const struct inode_operations nfs4_dir_inode_operations = {
 	.setattr	= nfs_setattr,
 	.getxattr	= generic_getxattr,
 	.setxattr	= generic_setxattr,
-	.listxattr	= generic_listxattr,
+	.listxattr	= nfs4_listxattr,
 	.removexattr	= generic_removexattr,
 };
 
@@ -8769,7 +8788,7 @@ static const struct inode_operations nfs4_file_inode_operations = {
 	.setattr	= nfs_setattr,
 	.getxattr	= generic_getxattr,
 	.setxattr	= generic_setxattr,
-	.listxattr	= generic_listxattr,
+	.listxattr	= nfs4_listxattr,
 	.removexattr	= generic_removexattr,
 };
 
diff --git a/fs/xattr.c b/fs/xattr.c
index c3af6c9670cb..2c7776403aba 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -723,6 +723,8 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 
 	if (!buffer) {
 		for_each_xattr_handler(handlers, handler) {
+			if (!handler->list)
+				continue;
 			size += handler->list(handler, dentry, NULL, 0,
 					      NULL, 0);
 		}
@@ -730,6 +732,8 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 		char *buf = buffer;
 
 		for_each_xattr_handler(handlers, handler) {
+			if (!handler->list)
+				continue;
 			size = handler->list(handler, dentry, buf, buffer_size,
 					     NULL, 0);
 			if (size > buffer_size)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index ff81026f6ddb..37fdd5416a64 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1519,8 +1519,6 @@ static int smack_inode_getsecurity(const struct inode *inode,
  * @inode: the object
  * @buffer: where they go
  * @buffer_size: size of buffer
- *
- * Returns 0 on success, -EINVAL otherwise
  */
 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
 				    size_t buffer_size)
-- 
cgit v1.2.3


From 764a5c6b1fa4306dd7573c1d80914254909cd036 Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Wed, 2 Dec 2015 14:44:43 +0100
Subject: xattr handlers: Simplify list operation

Change the list operation to only return whether or not an attribute
should be listed.  Copying the attribute names into the buffer is moved
to the callers.

Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/ext2/xattr.c              | 15 +++++---
 fs/ext2/xattr_security.c     | 17 ---------
 fs/ext2/xattr_trusted.c      | 19 ++--------
 fs/ext2/xattr_user.c         | 19 ++--------
 fs/ext4/xattr.c              | 17 +++++----
 fs/ext4/xattr_security.c     | 18 ----------
 fs/ext4/xattr_trusted.c      | 19 ++--------
 fs/ext4/xattr_user.c         | 19 ++--------
 fs/f2fs/xattr.c              | 82 ++++++++++++++------------------------------
 fs/jffs2/security.c          | 16 ---------
 fs/jffs2/xattr.c             | 26 ++++++++------
 fs/jffs2/xattr_trusted.c     | 17 ++-------
 fs/jffs2/xattr_user.c        | 16 ---------
 fs/nfs/nfs4proc.c            | 14 ++------
 fs/posix_acl.c               | 17 ++-------
 fs/reiserfs/xattr.c          | 13 +++----
 fs/reiserfs/xattr_security.c | 16 ++-------
 fs/reiserfs/xattr_trusted.c  | 15 ++------
 fs/reiserfs/xattr_user.c     | 14 ++------
 fs/squashfs/xattr.c          | 35 +++++--------------
 fs/xattr.c                   | 20 ++++++-----
 include/linux/xattr.h        |  4 +--
 22 files changed, 113 insertions(+), 335 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index fa70848afa8f..cd95d14f9cc2 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -292,16 +292,21 @@ bad_block:	ext2_error(inode->i_sb, "ext2_xattr_list",
 		const struct xattr_handler *handler =
 			ext2_xattr_handler(entry->e_name_index);
 
-		if (handler) {
-			size_t size = handler->list(handler, dentry, buffer,
-						    rest, entry->e_name,
-						    entry->e_name_len);
+		if (handler && (!handler->list || handler->list(dentry))) {
+			const char *prefix = handler->prefix ?: handler->name;
+			size_t prefix_len = strlen(prefix);
+			size_t size = prefix_len + entry->e_name_len + 1;
+
 			if (buffer) {
 				if (size > rest) {
 					error = -ERANGE;
 					goto cleanup;
 				}
-				buffer += size;
+				memcpy(buffer, prefix, prefix_len);
+				buffer += prefix_len;
+				memcpy(buffer, entry->e_name, entry->e_name_len);
+				buffer += entry->e_name_len;
+				*buffer++ = 0;
 			}
 			rest -= size;
 		}
diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index 118bf231bc7f..ba97f243b050 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -7,22 +7,6 @@
 #include <linux/security.h>
 #include "xattr.h"
 
-static size_t
-ext2_xattr_security_list(const struct xattr_handler *handler,
-			 struct dentry *dentry, char *list, size_t list_size,
-			 const char *name, size_t name_len)
-{
-	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
-	const size_t total_len = prefix_len + name_len + 1;
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
-}
-
 static int
 ext2_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
@@ -67,7 +51,6 @@ ext2_init_security(struct inode *inode, struct inode *dir,
 
 const struct xattr_handler ext2_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
-	.list	= ext2_xattr_security_list,
 	.get	= ext2_xattr_security_get,
 	.set	= ext2_xattr_security_set,
 };
diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
index 3f8f2bc6539e..2c94d1930626 100644
--- a/fs/ext2/xattr_trusted.c
+++ b/fs/ext2/xattr_trusted.c
@@ -8,23 +8,10 @@
 #include "ext2.h"
 #include "xattr.h"
 
-static size_t
-ext2_xattr_trusted_list(const struct xattr_handler *handler,
-			struct dentry *dentry, char *list, size_t list_size,
-			const char *name, size_t name_len)
+static bool
+ext2_xattr_trusted_list(struct dentry *dentry)
 {
-	const int prefix_len = XATTR_TRUSTED_PREFIX_LEN;
-	const size_t total_len = prefix_len + name_len + 1;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return 0;
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
+	return capable(CAP_SYS_ADMIN);
 }
 
 static int
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
index afd45ab1218c..72a2a96d677f 100644
--- a/fs/ext2/xattr_user.c
+++ b/fs/ext2/xattr_user.c
@@ -10,23 +10,10 @@
 #include "ext2.h"
 #include "xattr.h"
 
-static size_t
-ext2_xattr_user_list(const struct xattr_handler *handler,
-		     struct dentry *dentry, char *list, size_t list_size,
-		     const char *name, size_t name_len)
+static bool
+ext2_xattr_user_list(struct dentry *dentry)
 {
-	const size_t prefix_len = XATTR_USER_PREFIX_LEN;
-	const size_t total_len = prefix_len + name_len + 1;
-
-	if (!test_opt(dentry->d_sb, XATTR_USER))
-		return 0;
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_USER_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
+	return test_opt(dentry->d_sb, XATTR_USER);
 }
 
 static int
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 6b6b3e751f8c..e9b9afdd1d96 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -404,19 +404,24 @@ ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
 		const struct xattr_handler *handler =
 			ext4_xattr_handler(entry->e_name_index);
 
-		if (handler) {
-			size_t size = handler->list(handler, dentry, buffer,
-						    rest, entry->e_name,
-						    entry->e_name_len);
+		if (handler && (!handler->list || handler->list(dentry))) {
+			const char *prefix = handler->prefix ?: handler->name;
+			size_t prefix_len = strlen(prefix);
+			size_t size = prefix_len + entry->e_name_len + 1;
+
 			if (buffer) {
 				if (size > rest)
 					return -ERANGE;
-				buffer += size;
+				memcpy(buffer, prefix, prefix_len);
+				buffer += prefix_len;
+				memcpy(buffer, entry->e_name, entry->e_name_len);
+				buffer += entry->e_name_len;
+				*buffer++ = 0;
 			}
 			rest -= size;
 		}
 	}
-	return buffer_size - rest;
+	return buffer_size - rest;  /* total size */
 }
 
 static int
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 195abc4a88bb..3e81bdca071a 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -11,23 +11,6 @@
 #include "ext4.h"
 #include "xattr.h"
 
-static size_t
-ext4_xattr_security_list(const struct xattr_handler *handler,
-			 struct dentry *dentry, char *list, size_t list_size,
-			 const char *name, size_t name_len)
-{
-	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
-	const size_t total_len = prefix_len + name_len + 1;
-
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
-}
-
 static int
 ext4_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
@@ -75,7 +58,6 @@ ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
 
 const struct xattr_handler ext4_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
-	.list	= ext4_xattr_security_list,
 	.get	= ext4_xattr_security_get,
 	.set	= ext4_xattr_security_set,
 };
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index 121fdf9fdc02..2a3c6f9b8cb8 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -12,23 +12,10 @@
 #include "ext4.h"
 #include "xattr.h"
 
-static size_t
-ext4_xattr_trusted_list(const struct xattr_handler *handler,
-			struct dentry *dentry, char *list, size_t list_size,
-			const char *name, size_t name_len)
+static bool
+ext4_xattr_trusted_list(struct dentry *dentry)
 {
-	const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
-	const size_t total_len = prefix_len + name_len + 1;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return 0;
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
+	return capable(CAP_SYS_ADMIN);
 }
 
 static int
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index 577fc122d884..d152f431e432 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -11,23 +11,10 @@
 #include "ext4.h"
 #include "xattr.h"
 
-static size_t
-ext4_xattr_user_list(const struct xattr_handler *handler,
-		     struct dentry *dentry, char *list, size_t list_size,
-		     const char *name, size_t name_len)
+static bool
+ext4_xattr_user_list(struct dentry *dentry)
 {
-	const size_t prefix_len = XATTR_USER_PREFIX_LEN;
-	const size_t total_len = prefix_len + name_len + 1;
-
-	if (!test_opt(dentry->d_sb, XATTR_USER))
-		return 0;
-
-	if (list && total_len <= list_size) {
-		memcpy(list, XATTR_USER_PREFIX, prefix_len);
-		memcpy(list+prefix_len, name, name_len);
-		list[prefix_len + name_len] = '\0';
-	}
-	return total_len;
+	return test_opt(dentry->d_sb, XATTR_USER);
 }
 
 static int
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 21cfe516034f..036952a945fa 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -25,40 +25,6 @@
 #include "f2fs.h"
 #include "xattr.h"
 
-static size_t f2fs_xattr_generic_list(const struct xattr_handler *handler,
-		struct dentry *dentry, char *list, size_t list_size,
-		const char *name, size_t len)
-{
-	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
-	const char *prefix;
-	int total_len, prefix_len;
-
-	switch (handler->flags) {
-	case F2FS_XATTR_INDEX_USER:
-		if (!test_opt(sbi, XATTR_USER))
-			return -EOPNOTSUPP;
-		break;
-	case F2FS_XATTR_INDEX_TRUSTED:
-		if (!capable(CAP_SYS_ADMIN))
-			return -EPERM;
-		break;
-	case F2FS_XATTR_INDEX_SECURITY:
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	prefix = xattr_prefix(handler);
-	prefix_len = strlen(prefix);
-	total_len = prefix_len + len + 1;
-	if (list && total_len <= list_size) {
-		memcpy(list, prefix, prefix_len);
-		memcpy(list + prefix_len, name, len);
-		list[prefix_len + len] = '\0';
-	}
-	return total_len;
-}
-
 static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
 		struct dentry *dentry, const char *name, void *buffer,
 		size_t size)
@@ -107,17 +73,16 @@ static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
 					value, size, NULL, flags);
 }
 
-static size_t f2fs_xattr_advise_list(const struct xattr_handler *handler,
-		struct dentry *dentry, char *list, size_t list_size,
-		const char *name, size_t len)
+static bool f2fs_xattr_user_list(struct dentry *dentry)
 {
-	const char *xname = F2FS_SYSTEM_ADVISE_NAME;
-	size_t size;
+	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+
+	return test_opt(sbi, XATTR_USER);
+}
 
-	size = strlen(xname) + 1;
-	if (list && size <= list_size)
-		memcpy(list, xname, size);
-	return size;
+static bool f2fs_xattr_trusted_list(struct dentry *dentry)
+{
+	return capable(CAP_SYS_ADMIN);
 }
 
 static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
@@ -175,7 +140,7 @@ int f2fs_init_security(struct inode *inode, struct inode *dir,
 const struct xattr_handler f2fs_xattr_user_handler = {
 	.prefix	= XATTR_USER_PREFIX,
 	.flags	= F2FS_XATTR_INDEX_USER,
-	.list	= f2fs_xattr_generic_list,
+	.list	= f2fs_xattr_user_list,
 	.get	= f2fs_xattr_generic_get,
 	.set	= f2fs_xattr_generic_set,
 };
@@ -183,7 +148,7 @@ const struct xattr_handler f2fs_xattr_user_handler = {
 const struct xattr_handler f2fs_xattr_trusted_handler = {
 	.prefix	= XATTR_TRUSTED_PREFIX,
 	.flags	= F2FS_XATTR_INDEX_TRUSTED,
-	.list	= f2fs_xattr_generic_list,
+	.list	= f2fs_xattr_trusted_list,
 	.get	= f2fs_xattr_generic_get,
 	.set	= f2fs_xattr_generic_set,
 };
@@ -191,7 +156,6 @@ const struct xattr_handler f2fs_xattr_trusted_handler = {
 const struct xattr_handler f2fs_xattr_advise_handler = {
 	.name	= F2FS_SYSTEM_ADVISE_NAME,
 	.flags	= F2FS_XATTR_INDEX_ADVISE,
-	.list   = f2fs_xattr_advise_list,
 	.get    = f2fs_xattr_advise_get,
 	.set    = f2fs_xattr_advise_set,
 };
@@ -199,7 +163,6 @@ const struct xattr_handler f2fs_xattr_advise_handler = {
 const struct xattr_handler f2fs_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
 	.flags	= F2FS_XATTR_INDEX_SECURITY,
-	.list	= f2fs_xattr_generic_list,
 	.get	= f2fs_xattr_generic_get,
 	.set	= f2fs_xattr_generic_set,
 };
@@ -447,20 +410,27 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 	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;
 
-		if (!handler)
+		if (!handler || (handler->list && !handler->list(dentry)))
 			continue;
 
-		size = handler->list(handler, dentry, buffer, rest,
-				     entry->e_name, entry->e_name_len);
-		if (buffer && size > rest) {
-			error = -ERANGE;
-			goto cleanup;
+		prefix = handler->prefix ?: handler->name;
+		prefix_len = strlen(prefix);
+		size = prefix_len + entry->e_name_len + 1;
+		if (buffer) {
+			if (size > rest) {
+				error = -ERANGE;
+				goto cleanup;
+			}
+			memcpy(buffer, prefix, prefix_len);
+			buffer += prefix_len;
+			memcpy(buffer, entry->e_name, entry->e_name_len);
+			buffer += entry->e_name_len;
+			*buffer++ = 0;
 		}
-
-		if (buffer)
-			buffer += size;
 		rest -= size;
 	}
 	error = buffer_size - rest;
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index ea79932cd665..7a28facd7175 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -64,24 +64,8 @@ static int jffs2_security_setxattr(const struct xattr_handler *handler,
 				 name, buffer, size, flags);
 }
 
-static size_t jffs2_security_listxattr(const struct xattr_handler *handler,
-				       struct dentry *dentry, char *list,
-				       size_t list_size, const char *name,
-				       size_t name_len)
-{
-	size_t retlen = XATTR_SECURITY_PREFIX_LEN + name_len + 1;
-
-	if (list && retlen <= list_size) {
-		strcpy(list, XATTR_SECURITY_PREFIX);
-		strcpy(list + XATTR_SECURITY_PREFIX_LEN, name);
-	}
-
-	return retlen;
-}
-
 const struct xattr_handler jffs2_security_xattr_handler = {
 	.prefix = XATTR_SECURITY_PREFIX,
-	.list = jffs2_security_listxattr,
 	.set = jffs2_security_setxattr,
 	.get = jffs2_security_getxattr
 };
diff --git a/fs/jffs2/xattr.c b/fs/jffs2/xattr.c
index 4c2c03663533..da3e18503c65 100644
--- a/fs/jffs2/xattr.c
+++ b/fs/jffs2/xattr.c
@@ -967,7 +967,8 @@ ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 	struct jffs2_xattr_ref *ref, **pref;
 	struct jffs2_xattr_datum *xd;
 	const struct xattr_handler *xhandle;
-	ssize_t len, rc;
+	const char *prefix;
+	ssize_t prefix_len, len, rc;
 	int retry = 0;
 
 	rc = check_xattr_ref_inode(c, ic);
@@ -998,18 +999,23 @@ ssize_t jffs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
 			}
 		}
 		xhandle = xprefix_to_handler(xd->xprefix);
-		if (!xhandle)
+		if (!xhandle || (xhandle->list && !xhandle->list(dentry)))
 			continue;
+		prefix = xhandle->prefix ?: xhandle->name;
+		prefix_len = strlen(prefix);
+		rc = prefix_len + xd->name_len + 1;
+
 		if (buffer) {
-			rc = xhandle->list(xhandle, dentry, buffer + len,
-					   size - len, xd->xname,
-					   xd->name_len);
-		} else {
-			rc = xhandle->list(xhandle, dentry, NULL, 0,
-					   xd->xname, xd->name_len);
+			if (rc > size - len) {
+				rc = -ERANGE;
+				goto out;
+			}
+			memcpy(buffer, prefix, prefix_len);
+			buffer += prefix_len;
+			memcpy(buffer, xd->xname, xd->name_len);
+			buffer += xd->name_len;
+			*buffer++ = 0;
 		}
-		if (rc < 0)
-			goto out;
 		len += rc;
 	}
 	rc = len;
diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c
index 8b55fe44c777..b2555ef07a12 100644
--- a/fs/jffs2/xattr_trusted.c
+++ b/fs/jffs2/xattr_trusted.c
@@ -32,22 +32,9 @@ static int jffs2_trusted_setxattr(const struct xattr_handler *handler,
 				 name, buffer, size, flags);
 }
 
-static size_t jffs2_trusted_listxattr(const struct xattr_handler *handler,
-				      struct dentry *dentry, char *list,
-				      size_t list_size, const char *name,
-				      size_t name_len)
+static bool jffs2_trusted_listxattr(struct dentry *dentry)
 {
-	size_t retlen = XATTR_TRUSTED_PREFIX_LEN + name_len + 1;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return 0;
-
-	if (list && retlen<=list_size) {
-		strcpy(list, XATTR_TRUSTED_PREFIX);
-		strcpy(list + XATTR_TRUSTED_PREFIX_LEN, name);
-	}
-
-	return retlen;
+	return capable(CAP_SYS_ADMIN);
 }
 
 const struct xattr_handler jffs2_trusted_xattr_handler = {
diff --git a/fs/jffs2/xattr_user.c b/fs/jffs2/xattr_user.c
index b04335b84833..539bd630b5e4 100644
--- a/fs/jffs2/xattr_user.c
+++ b/fs/jffs2/xattr_user.c
@@ -32,24 +32,8 @@ static int jffs2_user_setxattr(const struct xattr_handler *handler,
 				 name, buffer, size, flags);
 }
 
-static size_t jffs2_user_listxattr(const struct xattr_handler *handler,
-				   struct dentry *dentry, char *list,
-				   size_t list_size, const char *name,
-				   size_t name_len)
-{
-	size_t retlen = XATTR_USER_PREFIX_LEN + name_len + 1;
-
-	if (list && retlen <= list_size) {
-		strcpy(list, XATTR_USER_PREFIX);
-		strcpy(list + XATTR_USER_PREFIX_LEN, name);
-	}
-
-	return retlen;
-}
-
 const struct xattr_handler jffs2_user_xattr_handler = {
 	.prefix = XATTR_USER_PREFIX,
-	.list = jffs2_user_listxattr,
 	.set = jffs2_user_setxattr,
 	.get = jffs2_user_getxattr
 };
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index dbfade2602c9..c57d1332c1c8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6263,19 +6263,9 @@ static int nfs4_xattr_get_nfs4_acl(const struct xattr_handler *handler,
 	return nfs4_proc_get_acl(d_inode(dentry), buf, buflen);
 }
 
-static size_t nfs4_xattr_list_nfs4_acl(const struct xattr_handler *handler,
-				       struct dentry *dentry, char *list,
-				       size_t list_len, const char *name,
-				       size_t name_len)
+static bool nfs4_xattr_list_nfs4_acl(struct dentry *dentry)
 {
-	size_t len = sizeof(XATTR_NAME_NFSV4_ACL);
-
-	if (!nfs4_server_supports_acls(NFS_SERVER(d_inode(dentry))))
-		return 0;
-
-	if (list && len <= list_len)
-		memcpy(list, XATTR_NAME_NFSV4_ACL, len);
-	return len;
+	return nfs4_server_supports_acls(NFS_SERVER(d_inode(dentry)));
 }
 
 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 17efd76978c8..711dd5170376 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -823,21 +823,10 @@ out:
 	return ret;
 }
 
-static size_t
-posix_acl_xattr_list(const struct xattr_handler *handler,
-		     struct dentry *dentry, char *list, size_t list_size,
-		     const char *name, size_t name_len)
+static bool
+posix_acl_xattr_list(struct dentry *dentry)
 {
-	const char *xname = handler->name;
-	size_t size;
-
-	if (!IS_POSIXACL(d_backing_inode(dentry)))
-		return 0;
-
-	size = strlen(xname) + 1;
-	if (list && size <= list_size)
-		memcpy(list, xname, size);
-	return size;
+	return IS_POSIXACL(d_backing_inode(dentry));
 }
 
 const struct xattr_handler posix_acl_access_xattr_handler = {
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index efe2ed3c13c5..e5ddb4e5ea94 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -840,19 +840,16 @@ static int listxattr_filler(struct dir_context *ctx, const char *name,
 
 		handler = find_xattr_handler_prefix(b->dentry->d_sb->s_xattr,
 						    name);
-		if (!handler)	/* Unsupported xattr name */
+		if (!handler /* Unsupported xattr name */ ||
+		    (handler->list && !handler->list(b->dentry)))
 			return 0;
+		size = namelen + 1;
 		if (b->buf) {
-			size = handler->list(handler, b->dentry,
-					     b->buf + b->pos, b->size, name,
-					     namelen);
 			if (size > b->size)
 				return -ERANGE;
-		} else {
-			size = handler->list(handler, b->dentry,
-					     NULL, 0, name, namelen);
+			memcpy(b->buf + b->pos, name, namelen);
+			b->buf[b->pos + namelen] = 0;
 		}
-
 		b->pos += size;
 	}
 	return 0;
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index ac659af431ae..ab0217d32039 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -34,21 +34,9 @@ security_set(const struct xattr_handler *handler, struct dentry *dentry,
 	return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags);
 }
 
-static size_t security_list(const struct xattr_handler *handler,
-			    struct dentry *dentry, char *list, size_t list_len,
-			    const char *name, size_t namelen)
+static bool security_list(struct dentry *dentry)
 {
-	const size_t len = namelen + 1;
-
-	if (IS_PRIVATE(d_inode(dentry)))
-		return 0;
-
-	if (list && len <= list_len) {
-		memcpy(list, name, namelen);
-		list[namelen] = '\0';
-	}
-
-	return len;
+	return !IS_PRIVATE(d_inode(dentry));
 }
 
 /* Initializes the security context for a new inode and returns the number
diff --git a/fs/reiserfs/xattr_trusted.c b/fs/reiserfs/xattr_trusted.c
index a338adf1b8b4..64b67aa643a9 100644
--- a/fs/reiserfs/xattr_trusted.c
+++ b/fs/reiserfs/xattr_trusted.c
@@ -33,20 +33,9 @@ trusted_set(const struct xattr_handler *handler, struct dentry *dentry,
 	return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags);
 }
 
-static size_t trusted_list(const struct xattr_handler *handler,
-			   struct dentry *dentry, char *list, size_t list_size,
-			   const char *name, size_t name_len)
+static bool trusted_list(struct dentry *dentry)
 {
-	const size_t len = name_len + 1;
-
-	if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(d_inode(dentry)))
-		return 0;
-
-	if (list && len <= list_size) {
-		memcpy(list, name, name_len);
-		list[name_len] = '\0';
-	}
-	return len;
+	return capable(CAP_SYS_ADMIN) && !IS_PRIVATE(d_inode(dentry));
 }
 
 const struct xattr_handler reiserfs_xattr_trusted_handler = {
diff --git a/fs/reiserfs/xattr_user.c b/fs/reiserfs/xattr_user.c
index 39c9667191c5..12e6306f562a 100644
--- a/fs/reiserfs/xattr_user.c
+++ b/fs/reiserfs/xattr_user.c
@@ -30,19 +30,9 @@ user_set(const struct xattr_handler *handler, struct dentry *dentry,
 	return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags);
 }
 
-static size_t user_list(const struct xattr_handler *handler,
-			struct dentry *dentry, char *list, size_t list_size,
-			const char *name, size_t name_len)
+static bool user_list(struct dentry *dentry)
 {
-	const size_t len = name_len + 1;
-
-	if (!reiserfs_xattrs_user(dentry->d_sb))
-		return 0;
-	if (list && len <= list_size) {
-		memcpy(list, name, name_len);
-		list[name_len] = '\0';
-	}
-	return len;
+	return reiserfs_xattrs_user(dentry->d_sb);
 }
 
 const struct xattr_handler reiserfs_xattr_user_handler = {
diff --git a/fs/squashfs/xattr.c b/fs/squashfs/xattr.c
index 2f0ccbaa2d92..1e9de96288d8 100644
--- a/fs/squashfs/xattr.c
+++ b/fs/squashfs/xattr.c
@@ -58,7 +58,7 @@ ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
 		struct squashfs_xattr_entry entry;
 		struct squashfs_xattr_val val;
 		const struct xattr_handler *handler;
-		int name_size, prefix_size = 0;
+		int name_size;
 
 		err = squashfs_read_metadata(sb, &entry, &start, &offset,
 							sizeof(entry));
@@ -67,15 +67,16 @@ ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
 
 		name_size = le16_to_cpu(entry.size);
 		handler = squashfs_xattr_handler(le16_to_cpu(entry.type));
-		if (handler)
-			prefix_size = handler->list(handler, d, buffer, rest,
-						    NULL, name_size);
-		if (prefix_size) {
+		if (handler && (!handler->list || handler->list(d))) {
+			const char *prefix = handler->prefix ?: handler->name;
+			size_t prefix_size = strlen(prefix);
+
 			if (buffer) {
 				if (prefix_size + name_size + 1 > rest) {
 					err = -ERANGE;
 					goto failed;
 				}
+				memcpy(buffer, prefix, prefix_size);
 				buffer += prefix_size;
 			}
 			err = squashfs_read_metadata(sb, buffer, &start,
@@ -212,18 +213,6 @@ failed:
 }
 
 
-static size_t squashfs_xattr_handler_list(const struct xattr_handler *handler,
-					  struct dentry *d, char *list,
-					  size_t list_size, const char *name,
-					  size_t name_len)
-{
-	int len = strlen(handler->prefix);
-
-	if (list && len <= list_size)
-		memcpy(list, handler->prefix, len);
-	return len;
-}
-
 static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
 				      struct dentry *d, const char *name,
 				      void *buffer, size_t size)
@@ -238,22 +227,15 @@ static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
 static const struct xattr_handler squashfs_xattr_user_handler = {
 	.prefix	= XATTR_USER_PREFIX,
 	.flags	= SQUASHFS_XATTR_USER,
-	.list	= squashfs_xattr_handler_list,
 	.get	= squashfs_xattr_handler_get
 };
 
 /*
  * Trusted namespace support
  */
-static size_t squashfs_trusted_xattr_handler_list(const struct xattr_handler *handler,
-						  struct dentry *d, char *list,
-						  size_t list_size, const char *name,
-						  size_t name_len)
+static bool squashfs_trusted_xattr_handler_list(struct dentry *d)
 {
-	if (!capable(CAP_SYS_ADMIN))
-		return 0;
-	return squashfs_xattr_handler_list(handler, d, list, list_size, name,
-					   name_len);
+	return capable(CAP_SYS_ADMIN);
 }
 
 static const struct xattr_handler squashfs_xattr_trusted_handler = {
@@ -269,7 +251,6 @@ static const struct xattr_handler squashfs_xattr_trusted_handler = {
 static const struct xattr_handler squashfs_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
 	.flags	= SQUASHFS_XATTR_SECURITY,
-	.list	= squashfs_xattr_handler_list,
 	.get	= squashfs_xattr_handler_get
 };
 
diff --git a/fs/xattr.c b/fs/xattr.c
index 2c7776403aba..d7f5037a17b5 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -723,23 +723,25 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
 
 	if (!buffer) {
 		for_each_xattr_handler(handlers, handler) {
-			if (!handler->list)
+			if (!handler->name ||
+			    (handler->list && !handler->list(dentry)))
 				continue;
-			size += handler->list(handler, dentry, NULL, 0,
-					      NULL, 0);
+			size += strlen(handler->name) + 1;
 		}
 	} else {
 		char *buf = buffer;
+		size_t len;
 
 		for_each_xattr_handler(handlers, handler) {
-			if (!handler->list)
+			if (!handler->name ||
+			    (handler->list && !handler->list(dentry)))
 				continue;
-			size = handler->list(handler, dentry, buf, buffer_size,
-					     NULL, 0);
-			if (size > buffer_size)
+			len = strlen(handler->name);
+			if (len + 1 > buffer_size)
 				return -ERANGE;
-			buf += size;
-			buffer_size -= size;
+			memcpy(buf, handler->name, len + 1);
+			buf += len + 1;
+			buffer_size -= len + 1;
 		}
 		size = buf - buffer;
 	}
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index d23ce8e9af6f..4457541de3c9 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -28,9 +28,7 @@ struct xattr_handler {
 	const char *name;
 	const char *prefix;
 	int flags;      /* fs private flags */
-	size_t (*list)(const struct xattr_handler *, struct dentry *dentry,
-		       char *list, size_t list_size, const char *name,
-		       size_t name_len);
+	bool (*list)(struct dentry *dentry);
 	int (*get)(const struct xattr_handler *, struct dentry *dentry,
 		   const char *name, void *buffer, size_t size);
 	int (*set)(const struct xattr_handler *, struct dentry *dentry,
-- 
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