From 889ecf29edfa4102eec38fcb3d6fd6be9e41f8fc Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <djwong@kernel.org>
Date: Tue, 5 Jan 2021 17:45:33 -0800
Subject: xfs: convert metadata inode lookup keys to use paths

Convert the magic metadata inode lookup keys to use actual strings
for paths.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/libxfs/xfs_imeta.c | 48 +++++++++++++++++++++++++----------------------
 fs/xfs/libxfs/xfs_imeta.h | 17 +++++++++++++++--
 2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_imeta.c b/fs/xfs/libxfs/xfs_imeta.c
index 2d838a66a1bb..c091f564a276 100644
--- a/fs/xfs/libxfs/xfs_imeta.c
+++ b/fs/xfs/libxfs/xfs_imeta.c
@@ -48,26 +48,17 @@
  */
 
 /* Static metadata inode paths */
-
-const struct xfs_imeta_path XFS_IMETA_RTBITMAP = {
-	.bogus = 0,
-};
-
-const struct xfs_imeta_path XFS_IMETA_RTSUMMARY = {
-	.bogus = 1,
-};
-
-const struct xfs_imeta_path XFS_IMETA_USRQUOTA = {
-	.bogus = 2,
-};
-
-const struct xfs_imeta_path XFS_IMETA_GRPQUOTA = {
-	.bogus = 3,
-};
-
-const struct xfs_imeta_path XFS_IMETA_PRJQUOTA = {
-	.bogus = 4,
-};
+static const char *rtbitmap_path[]	= {"realtime", "0.bitmap"};
+static const char *rtsummary_path[]	= {"realtime", "0.summary"};
+static const char *usrquota_path[]	= {"quota", "user"};
+static const char *grpquota_path[]	= {"quota", "group"};
+static const char *prjquota_path[]	= {"quota", "project"};
+
+XFS_IMETA_DEFINE_PATH(XFS_IMETA_RTBITMAP,	rtbitmap_path);
+XFS_IMETA_DEFINE_PATH(XFS_IMETA_RTSUMMARY,	rtsummary_path);
+XFS_IMETA_DEFINE_PATH(XFS_IMETA_USRQUOTA,	usrquota_path);
+XFS_IMETA_DEFINE_PATH(XFS_IMETA_GRPQUOTA,	grpquota_path);
+XFS_IMETA_DEFINE_PATH(XFS_IMETA_PRJQUOTA,	prjquota_path);
 
 /* Are these two paths equal? */
 STATIC bool
@@ -75,7 +66,20 @@ xfs_imeta_path_compare(
 	const struct xfs_imeta_path	*a,
 	const struct xfs_imeta_path	*b)
 {
-	return a == b;
+	unsigned int			i;
+
+	if (a == b)
+		return true;
+
+	if (a->im_depth != b->im_depth)
+		return false;
+
+	for (i = 0; i < a->im_depth; i++)
+		if (a->im_path[i] != b->im_path[i] &&
+		    strcmp(a->im_path[i], b->im_path[i]))
+			return false;
+
+	return true;
 }
 
 /* Is this path ok? */
@@ -83,7 +87,7 @@ static inline bool
 xfs_imeta_path_check(
 	const struct xfs_imeta_path	*path)
 {
-	return true;
+	return path->im_depth <= XFS_IMETA_MAX_DEPTH;
 }
 
 /* Functions for storing and retrieving superblock inode values. */
diff --git a/fs/xfs/libxfs/xfs_imeta.h b/fs/xfs/libxfs/xfs_imeta.h
index 78a5ade91f04..8f2f56c15db7 100644
--- a/fs/xfs/libxfs/xfs_imeta.h
+++ b/fs/xfs/libxfs/xfs_imeta.h
@@ -6,10 +6,23 @@
 #ifndef __XFS_IMETA_H__
 #define __XFS_IMETA_H__
 
+/* How deep can we nest metadata dirs? */
+#define XFS_IMETA_MAX_DEPTH	64
+
+/* Form an imeta path from a simple array of strings. */
+#define XFS_IMETA_DEFINE_PATH(name, path) \
+const struct xfs_imeta_path name = { \
+	.im_path = (path), \
+	.im_depth = ARRAY_SIZE(path), \
+}
+
 /* Key for looking up metadata inodes. */
 struct xfs_imeta_path {
-	/* Temporary: integer to keep the static imeta definitions unique */
-	int		bogus;
+	/* Array of string pointers. */
+	const char	**im_path;
+
+	/* Number of strings in path. */
+	unsigned int	im_depth;
 };
 
 /* Cleanup widget for metadata inode creation and deletion. */
-- 
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