Linux 4.7 compat: handler->get() takes both dentry and inode

Signed-off-by: Chunwei Chen <david.chen@osnexus.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue openzfs#4665
ClusterHQ · Jun 7, 2016 · 92a5322 · 92a5322
1 parent 2a7a262
commit 92a5322
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Showing 2 changed files with 64 additions and 28 deletions.
diff --git a/config/kernel-xattr-handler.m4 b/config/kernel-xattr-handler.m4
@@ -62,74 +62,97 @@ dnl # Supported xattr handler get() interfaces checked newest to oldest.
 dnl #
 AC_DEFUN([ZFS_AC_KERNEL_XATTR_HANDLER_GET], [
 	dnl #
-	dnl # 4.4 API change,
-	dnl # The xattr_handler->get() callback was changed to take a
-	dnl # attr_handler, and handler_flags argument was removed and
-	dnl # should be accessed by handler->flags.
+	dnl # 4.7 API change,
+	dnl # The xattr_handler->get() callback was changed to take both
+	dnl # dentry and inode.
 	dnl #
-	AC_MSG_CHECKING([whether xattr_handler->get() wants xattr_handler])
+	AC_MSG_CHECKING([whether xattr_handler->get() wants both dentry and inode])
 	ZFS_LINUX_TRY_COMPILE([
 		#include <linux/xattr.h>
 
 		int get(const struct xattr_handler *handler,
-		    struct dentry *dentry, const char *name,
-		    void *buffer, size_t size) { return 0; }
+		    struct dentry *dentry, struct inode *inode,
+		    const char *name, void *buffer, size_t size) { return 0; }
 		static const struct xattr_handler
 		    xops __attribute__ ((unused)) = {
 			.get = get,
 		};
 	],[
 	],[
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_XATTR_GET_HANDLER, 1,
+		AC_DEFINE(HAVE_XATTR_GET_DENTRY_INODE, 1,
 		    [xattr_handler->get() wants xattr_handler])
 	],[
 		dnl #
-		dnl # 2.6.33 API change,
-		dnl # The xattr_handler->get() callback was changed to take
-		dnl # a dentry instead of an inode, and a handler_flags
-		dnl # argument was added.
+		dnl # 4.4 API change,
+		dnl # The xattr_handler->get() callback was changed to take a
+		dnl # attr_handler, and handler_flags argument was removed and
+		dnl # should be accessed by handler->flags.
 		dnl #
-		AC_MSG_RESULT(no)
-		AC_MSG_CHECKING([whether xattr_handler->get() wants dentry])
+		AC_MSG_CHECKING([whether xattr_handler->get() wants xattr_handler])
 		ZFS_LINUX_TRY_COMPILE([
 			#include <linux/xattr.h>
 
-			int get(struct dentry *dentry, const char *name,
-			    void *buffer, size_t size, int handler_flags)
-			    { return 0; }
+			int get(const struct xattr_handler *handler,
+			    struct dentry *dentry, const char *name,
+			    void *buffer, size_t size) { return 0; }
 			static const struct xattr_handler
 			    xops __attribute__ ((unused)) = {
 				.get = get,
 			};
 		],[
 		],[
 			AC_MSG_RESULT(yes)
-			AC_DEFINE(HAVE_XATTR_GET_DENTRY, 1,
-			    [xattr_handler->get() wants dentry])
+			AC_DEFINE(HAVE_XATTR_GET_HANDLER, 1,
+			    [xattr_handler->get() wants xattr_handler])
 		],[
 			dnl #
-			dnl # 2.6.32 API
+			dnl # 2.6.33 API change,
+			dnl # The xattr_handler->get() callback was changed to take
+			dnl # a dentry instead of an inode, and a handler_flags
+			dnl # argument was added.
 			dnl #
 			AC_MSG_RESULT(no)
-			AC_MSG_CHECKING(
-			    [whether xattr_handler->get() wants inode])
+			AC_MSG_CHECKING([whether xattr_handler->get() wants dentry])
 			ZFS_LINUX_TRY_COMPILE([
 				#include <linux/xattr.h>
 
-				int get(struct inode *ip, const char *name,
-				    void *buffer, size_t size) { return 0; }
+				int get(struct dentry *dentry, const char *name,
+				    void *buffer, size_t size, int handler_flags)
+				    { return 0; }
 				static const struct xattr_handler
 				    xops __attribute__ ((unused)) = {
 					.get = get,
 				};
 			],[
 			],[
 				AC_MSG_RESULT(yes)
-				AC_DEFINE(HAVE_XATTR_GET_INODE, 1,
-				    [xattr_handler->get() wants inode])
+				AC_DEFINE(HAVE_XATTR_GET_DENTRY, 1,
+				    [xattr_handler->get() wants dentry])
 			],[
-	                        AC_MSG_ERROR([no; please file a bug report])
+				dnl #
+				dnl # 2.6.32 API
+				dnl #
+				AC_MSG_RESULT(no)
+				AC_MSG_CHECKING(
+				    [whether xattr_handler->get() wants inode])
+				ZFS_LINUX_TRY_COMPILE([
+					#include <linux/xattr.h>
+
+					int get(struct inode *ip, const char *name,
+					    void *buffer, size_t size) { return 0; }
+					static const struct xattr_handler
+					    xops __attribute__ ((unused)) = {
+						.get = get,
+					};
+				],[
+				],[
+					AC_MSG_RESULT(yes)
+					AC_DEFINE(HAVE_XATTR_GET_INODE, 1,
+					    [xattr_handler->get() wants inode])
+				],[
+					AC_MSG_ERROR([no; please file a bug report])
+				])
 			])
 		])
 	])

diff --git a/include/linux/xattr_compat.h b/include/linux/xattr_compat.h
@@ -101,13 +101,26 @@ fn(struct inode *ip, char *list, size_t list_size,			\
 }
 #endif
 
+/*
+ * 4.7 API change,
+ * The xattr_handler->get() callback was changed to take a both dentry and
+ * inode, because the dentry might not be attached to an inode yet.
+ */
+#if defined(HAVE_XATTR_GET_DENTRY_INODE)
+#define	ZPL_XATTR_GET_WRAPPER(fn)					\
+static int								\
+fn(const struct xattr_handler *handler, struct dentry *dentry,		\
+    struct inode *inode, const char *name, void *buffer, size_t size)	\
+{									\
+	return (__ ## fn(inode, name, buffer, size));			\
+}
 /*
  * 4.4 API change,
  * The xattr_handler->get() callback was changed to take a xattr_handler,
  * and handler_flags argument was removed and should be accessed by
  * handler->flags.
  */
-#if defined(HAVE_XATTR_GET_HANDLER)
+#elif defined(HAVE_XATTR_GET_HANDLER)
 #define	ZPL_XATTR_GET_WRAPPER(fn)					\
 static int								\
 fn(const struct xattr_handler *handler, struct dentry *dentry,		\