--- zzzz-none-000/linux-3.10.107/fs/9p/xattr.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/9p/xattr.c	2021-02-04 17:41:59.000000000 +0000
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/uio.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -25,50 +26,34 @@
 			   void *buffer, size_t buffer_size)
 {
 	ssize_t retval;
-	int msize, read_count;
-	u64 offset = 0, attr_size;
+	u64 attr_size;
 	struct p9_fid *attr_fid;
+	struct kvec kvec = {.iov_base = buffer, .iov_len = buffer_size};
+	struct iov_iter to;
+	int err;
+
+	iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size);
 
 	attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
 	if (IS_ERR(attr_fid)) {
 		retval = PTR_ERR(attr_fid);
 		p9_debug(P9_DEBUG_VFS, "p9_client_attrwalk failed %zd\n",
 			 retval);
-		attr_fid = NULL;
-		goto error;
-	}
-	if (!buffer_size) {
-		/* request to get the attr_size */
-		retval = attr_size;
-		goto error;
+		return retval;
 	}
 	if (attr_size > buffer_size) {
-		retval = -ERANGE;
-		goto error;
-	}
-	msize = attr_fid->clnt->msize;
-	while (attr_size) {
-		if (attr_size > (msize - P9_IOHDRSZ))
-			read_count = msize - P9_IOHDRSZ;
+		if (!buffer_size) /* request to get the attr_size */
+			retval = attr_size;
 		else
-			read_count = attr_size;
-		read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
-					NULL, offset, read_count);
-		if (read_count < 0) {
-			/* error in xattr read */
-			retval = read_count;
-			goto error;
-		}
-		offset += read_count;
-		attr_size -= read_count;
+			retval = -ERANGE;
+	} else {
+		iov_iter_truncate(&to, attr_size);
+		retval = p9_client_read(attr_fid, 0, &to, &err);
+		if (err)
+			retval = err;
 	}
-	/* Total read xattr bytes */
-	retval = offset;
-error:
-	if (attr_fid)
-		p9_client_clunk(attr_fid);
+	p9_client_clunk(attr_fid);
 	return retval;
-
 }
 
 
@@ -120,8 +105,11 @@
 int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
 		   const void *value, size_t value_len, int flags)
 {
-	u64 offset = 0;
-	int retval, msize, write_count;
+	struct kvec kvec = {.iov_base = (void *)value, .iov_len = value_len};
+	struct iov_iter from;
+	int retval;
+
+	iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len);
 
 	p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n",
 		 name, value_len, flags);
@@ -135,29 +123,13 @@
 	 * On success fid points to xattr
 	 */
 	retval = p9_client_xattrcreate(fid, name, value_len, flags);
-	if (retval < 0) {
+	if (retval < 0)
 		p9_debug(P9_DEBUG_VFS, "p9_client_xattrcreate failed %d\n",
 			 retval);
-		p9_client_clunk(fid);
-		return retval;
-	}
-	msize = fid->clnt->msize;
-	while (value_len) {
-		if (value_len > (msize - P9_IOHDRSZ))
-			write_count = msize - P9_IOHDRSZ;
-		else
-			write_count = value_len;
-		write_count = p9_client_write(fid, ((char *)value)+offset,
-					NULL, offset, write_count);
-		if (write_count < 0) {
-			/* error in xattr write */
-			retval = write_count;
-			break;
-		}
-		offset += write_count;
-		value_len -= write_count;
-	}
-	return p9_client_clunk(fid);
+	else
+		p9_client_write(fid, 0, &from, &retval);
+	p9_client_clunk(fid);
+	return retval;
 }
 
 ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
@@ -165,11 +137,57 @@
 	return v9fs_xattr_get(dentry, NULL, buffer, buffer_size);
 }
 
+static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
+				  struct dentry *dentry, const char *name,
+				  void *buffer, size_t size)
+{
+	const char *full_name = xattr_full_name(handler, name);
+
+	if (strcmp(name, "") == 0)
+		return -EINVAL;
+	return v9fs_xattr_get(dentry, full_name, buffer, size);
+}
+
+static int v9fs_xattr_handler_set(const struct xattr_handler *handler,
+				  struct dentry *dentry, const char *name,
+				  const void *value, size_t size, int flags)
+{
+	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);
+}
+
+static struct xattr_handler v9fs_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.get	= v9fs_xattr_handler_get,
+	.set	= v9fs_xattr_handler_set,
+};
+
+static struct xattr_handler v9fs_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.get	= v9fs_xattr_handler_get,
+	.set	= v9fs_xattr_handler_set,
+};
+
+#ifdef CONFIG_9P_FS_SECURITY
+static struct xattr_handler v9fs_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.get	= v9fs_xattr_handler_get,
+	.set	= v9fs_xattr_handler_set,
+};
+#endif
+
 const struct xattr_handler *v9fs_xattr_handlers[] = {
 	&v9fs_xattr_user_handler,
+	&v9fs_xattr_trusted_handler,
 #ifdef CONFIG_9P_FS_POSIX_ACL
 	&v9fs_xattr_acl_access_handler,
 	&v9fs_xattr_acl_default_handler,
 #endif
+#ifdef CONFIG_9P_FS_SECURITY
+	&v9fs_xattr_security_handler,
+#endif
 	NULL
 };