Cleanup vn_rename() and vn_remove()

zfsonlinux/spl#bcb15891ab394e11615eee08bba1fd85ac32e158 implemented Linux 3.6+ support by adding duplicate vn_rename and vn_remove functions. The new ones were cleaner, but the duplicate functions made the codebase less maintainable. This adds some compatibility shims that allow us to retire the older vn_rename and vn_remove in favor of the new ones on old kernels. The result is a net 143 line reduction in lines of code and a cleaner codebase. Signed-off-by: Richard Yao <[email protected]> Signed-off-by: Brian Behlendorf <[email protected]> Closes openzfs#370
kernelOfTruth · Aug 13, 2014 · ec18fe3 · ec18fe3
1 parent 2fc44f6
commit ec18fe3
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Showing 5 changed files with 129 additions and 305 deletions.
diff --git a/config/spl-build.m4 b/config/spl-build.m4
@@ -28,7 +28,6 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
 	SPL_AC_TYPE_UINTPTR_T
 	SPL_AC_2ARGS_REGISTER_SYSCTL
 	SPL_AC_SHRINKER_CALLBACK
-	SPL_AC_PATH_IN_NAMEIDATA
 	SPL_AC_TASK_CURR
 	SPL_AC_CTL_UNNUMBERED
 	SPL_AC_CTL_NAME
@@ -81,9 +80,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
 	SPL_AC_KERNEL_FALLOCATE
 	SPL_AC_SHRINK_DCACHE_MEMORY
 	SPL_AC_SHRINK_ICACHE_MEMORY
-	SPL_AC_KERN_PATH_PARENT_HEADER
-	SPL_AC_KERN_PATH_PARENT_SYMBOL
-	SPL_AC_KERN_PATH_LOCKED
+	SPL_AC_KERN_PATH
 	SPL_AC_CONFIG_KALLSYMS
 	SPL_AC_CONFIG_ZLIB_INFLATE
 	SPL_AC_CONFIG_ZLIB_DEFLATE
@@ -990,28 +987,6 @@ AC_DEFUN([SPL_AC_SHRINKER_CALLBACK],[
 	EXTRA_KCFLAGS="$tmp_flags"
 ])
 
-dnl #
-dnl # 2.6.25 API change,
-dnl # struct path entry added to struct nameidata
-dnl #
-AC_DEFUN([SPL_AC_PATH_IN_NAMEIDATA],
-	[AC_MSG_CHECKING([whether struct path used in struct nameidata])
-	SPL_LINUX_TRY_COMPILE([
-		#include <linux/namei.h>
-	],[
-		struct nameidata nd __attribute__ ((unused));
-
-		nd.path.mnt = NULL;
-		nd.path.dentry = NULL;
-	],[
-		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_PATH_IN_NAMEIDATA, 1,
-		          [struct path used in struct nameidata])
-	],[
-		AC_MSG_RESULT(no)
-	])
-])
-
 dnl #
 dnl # Custom SPL patch may export this system it is not required
 dnl #
@@ -2279,56 +2254,41 @@ AC_DEFUN([SPL_AC_SHRINK_ICACHE_MEMORY],
 ])
 
 dnl #
-dnl # 2.6.39 API compat,
-dnl # The path_lookup() function has been renamed to kern_path_parent()
-dnl # and the flags argument has been removed.  The only behavior now
-dnl # offered is that of LOOKUP_PARENT.  The spl already always passed
-dnl # this flag so dropping the flag does not impact us.
-dnl #
-AC_DEFUN([SPL_AC_KERN_PATH_PARENT_HEADER], [
-	SPL_CHECK_SYMBOL_HEADER(
-		[kern_path_parent],
-		[int kern_path_parent(const char \*, struct nameidata \*)],
-		[include/linux/namei.h],
-		[AC_DEFINE(HAVE_KERN_PATH_PARENT_HEADER, 1,
-		[kern_path_parent() is available])],
-		[])
-])
-
-dnl #
-dnl # 3.1 API compat,
-dnl # The kern_path_parent() symbol is no longer exported by the kernel.
-dnl # However, it remains the prefered interface and since we still have
-dnl # access to the prototype we dynamically lookup the required address.
+dnl # 2.6.28 API change
+dnl # The kern_path() function has been introduced. We adopt it as the new way
+dnl # of looking up paths. When it is not available, we emulate it using the
+dnl # older interfaces.
 dnl #
-AC_DEFUN([SPL_AC_KERN_PATH_PARENT_SYMBOL],
-	[AC_MSG_CHECKING([whether kern_path_parent() is available])
+AC_DEFUN([SPL_AC_KERN_PATH],
+	[AC_MSG_CHECKING([whether kern_path() is available])
 	SPL_LINUX_TRY_COMPILE_SYMBOL([
 		#include <linux/namei.h>
 	], [
-		kern_path_parent(NULL, NULL);
-	], [kern_path_parent], [fs/namei.c], [
+		int r = kern_path(NULL, 0, NULL);
+	], [kern_path], [fs/namei.c], [
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_KERN_PATH_PARENT_SYMBOL, 1,
-		          [kern_path_parent() is available])
+		AC_DEFINE(HAVE_KERN_PATH, 1,
+		          [kern_path() is available])
 	], [
 		AC_MSG_RESULT(no)
-	])
-])
+		AC_MSG_CHECKING([whether path_lookup() is available])
+		SPL_LINUX_TRY_COMPILE_SYMBOL([
+			#include <linux/namei.h>
+		], [
+			int r = path_lookup(NULL, 0, NULL);
+		], [path_lookup], [fs/namei.c], [
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(HAVE_KERN_PATH, 1,
+				  [kern_path() is available])
+		], [
+			AC_MSG_RESULT(no)
+			AC_MSG_ERROR([
+	*** Neither kern_path() nor path_lookup() is available.
+	*** Please file an issue:
+	*** https://github.com/zfsonlinux/spl/issues/new])
 
-dnl #
-dnl # 3.6 API compat,
-dnl # The kern_path_parent() function was replaced by the kern_path_locked()
-dnl # function to eliminate all struct nameidata usage outside fs/namei.c.
-dnl #
-AC_DEFUN([SPL_AC_KERN_PATH_LOCKED], [
-	SPL_CHECK_SYMBOL_HEADER(
-		[kern_path_locked],
-		[struct dentry \*kern_path_locked(const char \*, struct path \*)],
-		[include/linux/namei.h],
-		[AC_DEFINE(HAVE_KERN_PATH_LOCKED, 1,
-		[kern_path_locked() is available])],
-		[])
+		])
+	])
 ])
 
 dnl #

diff --git a/include/linux/file_compat.h b/include/linux/file_compat.h
@@ -91,23 +91,5 @@ spl_filp_fallocate(struct file *fp, int mode, loff_t offset, loff_t len)
 #define spl_inode_unlock(ip)		(up(&(ip)->i_sem))
 #endif /* HAVE_INODE_I_MUTEX */
 
-#ifdef HAVE_KERN_PATH_PARENT_HEADER
-# ifndef HAVE_KERN_PATH_PARENT_SYMBOL
-typedef int (*kern_path_parent_t)(const char *, struct nameidata *);
-extern kern_path_parent_t kern_path_parent_fn;
-#  define spl_kern_path_parent(path, nd)	kern_path_parent_fn(path, nd)
-# else
-#  define spl_kern_path_parent(path, nd)	kern_path_parent(path, nd)
-# endif /* HAVE_KERN_PATH_PARENT_SYMBOL */
-#else
-# define spl_kern_path_parent(path, nd)	path_lookup(path, LOOKUP_PARENT, nd)
-#endif /* HAVE_KERN_PATH_PARENT_HEADER */
-
-#ifdef HAVE_KERN_PATH_LOCKED
-typedef struct dentry * (*kern_path_locked_t)(const char *, struct path *);
-extern kern_path_locked_t kern_path_locked_fn;
-# define spl_kern_path_locked(name, path)	kern_path_locked_fn(name, path)
-#endif /* HAVE_KERN_PATH_LOCKED */
-
 #endif /* SPL_FILE_COMPAT_H */
 
diff --git a/include/sys/vnode.h b/include/sys/vnode.h
@@ -103,14 +103,6 @@
 #define CREATE_XATTR_DIR	0x04
 #define ATTR_NOACLCHECK		0x20
 
-#ifdef HAVE_PATH_IN_NAMEIDATA
-# define nd_dentry	path.dentry
-# define nd_mnt		path.mnt
-#else
-# define nd_dentry	dentry
-# define nd_mnt		mnt
-#endif
-
 typedef enum vtype {
 	VNON		= 0,
 	VREG		= 1,
@@ -194,7 +186,6 @@ extern file_t *vn_getf(int fd);
 extern void vn_releasef(int fd);
 extern int vn_set_pwd(const char *filename);
 
-int spl_vn_init_kallsyms_lookup(void);
 int spl_vn_init(void);
 void spl_vn_fini(void);
 

diff --git a/module/spl/spl-generic.c b/module/spl/spl-generic.c
@@ -664,9 +664,6 @@ __init spl_init(void)
 	if ((rc = spl_kmem_init_kallsyms_lookup()))
 		SGOTO(out10, rc);
 
-	if ((rc = spl_vn_init_kallsyms_lookup()))
-		SGOTO(out10, rc);
-
 	printk(KERN_NOTICE "SPL: Loaded module v%s-%s%s\n", SPL_META_VERSION,
 	       SPL_META_RELEASE, SPL_DEBUG_STR);
 	SRETURN(rc);