From: Masatake YAMATO <yamato@redhat.com>
Date: Wed, 27 Jul 2022 19:17:34 +0000 (+0900)
Subject: lsfd: introduce a method table for supporting various anon inodes
X-Git-Tag: v2.39-rc1~550^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9a9c96b70c66d544550ec17176de71786340359f;p=thirdparty%2Futil-linux.git

lsfd: introduce a method table for supporting various anon inodes

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---

diff --git a/misc-utils/lsfd-unkn.c b/misc-utils/lsfd-unkn.c
index c7526818ed..34038e2b9a 100644
--- a/misc-utils/lsfd-unkn.c
+++ b/misc-utils/lsfd-unkn.c
@@ -25,6 +25,21 @@
 
 #include "lsfd.h"
 
+struct unkn {
+	struct file file;
+	struct anon_ops *anon_ops;
+	void *anon_data;
+};
+
+struct anon_ops {
+	char * (*get_name)(struct unkn *);
+	void (*init)(struct unkn *);
+	void (*free)(struct unkn *);
+	int (*handle_fdinfo)(struct unkn *, const char *, const char *);
+};
+
+static struct anon_ops anon_generic_ops;
+
 static bool unkn_fill_column(struct proc *proc __attribute__((__unused__)),
 			     struct file *file,
 			     struct libscols_line *ln,
@@ -32,15 +47,22 @@ static bool unkn_fill_column(struct proc *proc __attribute__((__unused__)),
 			     size_t column_index)
 {
 	char *str = NULL;
+	struct unkn *unkn = (struct unkn *)file;
 
 	switch(column_id) {
+	case COL_NAME:
+		if (unkn->anon_ops && unkn->anon_ops->get_name) {
+			str = unkn->anon_ops->get_name(unkn);
+			if (str)
+				break;
+		}
+		return false;
 	case COL_TYPE:
 		if (scols_line_set_data(ln, column_index, "UNKN"))
 			err(EXIT_FAILURE, _("failed to add output data"));
 		return true;
 	case COL_SOURCE:
-		if (major(file->stat.st_dev) == 0
-		    && strncmp(file->name, "anon_inode:", 11) == 0) {
+		if (unkn->anon_ops) {
 			str = strdup("anon_inodefs");
 			break;
 		}
@@ -56,8 +78,56 @@ static bool unkn_fill_column(struct proc *proc __attribute__((__unused__)),
 	return true;
 }
 
+static void unkn_init_content(struct file *file)
+{
+	struct unkn *unkn = (struct unkn *)file;
+
+	assert(file);
+	unkn->anon_ops = NULL;
+	unkn->anon_data = NULL;
+
+	if (major(file->stat.st_dev) == 0
+	    && strncmp(file->name, "anon_inode:", 11) == 0) {
+		unkn->anon_ops = &anon_generic_ops;
+		if (unkn->anon_ops->init)
+			unkn->anon_ops->init(unkn);
+	}
+}
+
+static void unkn_content_free(struct file *file)
+{
+	struct unkn *unkn = (struct unkn *)file;
+
+	assert(file);
+	if (unkn->anon_ops && unkn->anon_ops->free)
+		unkn->anon_ops->free((struct unkn *)file);
+}
+
+static int unkn_handle_fdinfo(struct file *file, const char *key, const char *value)
+{
+	struct unkn *unkn = (struct unkn *)file;
+
+	assert(file);
+	if (unkn->anon_ops && unkn->anon_ops->handle_fdinfo)
+		return unkn->anon_ops->handle_fdinfo(unkn, key, value);
+	return 0;		/* Should be handled in parents */
+}
+
+/*
+ * generic (fallback implementation)
+ */
+static struct anon_ops anon_generic_ops = {
+	.get_name = NULL,
+	.init = NULL,
+	.free = NULL,
+	.handle_fdinfo = NULL,
+};
+
 const struct file_class unkn_class = {
 	.super = &file_class,
-	.size = sizeof(struct file),
+	.size = sizeof(struct unkn),
 	.fill_column = unkn_fill_column,
+	.initialize_content = unkn_init_content,
+	.free_content = unkn_content_free,
+	.handle_fdinfo = unkn_handle_fdinfo,
 };