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>

3 files changed, 40 insertions, 19 deletions

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)