From: Masatake YAMATO <yamato@redhat.com>
Date: Wed, 8 Dec 2021 14:48:09 +0000 (+0900)
Subject: lsfd: add a helper function for reading bdevs in /prode/devices
X-Git-Tag: v2.38-rc1~96^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=00726e786564fef052fbc356b6435d156cecaf95;p=thirdparty%2Futil-linux.git

lsfd: add a helper function for reading bdevs in /prode/devices

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

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index d1c99d2fb8..4dec0f8082 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -90,6 +90,7 @@ struct devdrv {
 };
 
 static struct list_head chrdrvs;
+static struct list_head blkdrvs;
 
 /*
  * Column related stuffs
@@ -936,24 +937,53 @@ static void free_devdrv(struct devdrv *devdrv)
 	free(devdrv);
 }
 
-static void read_devices(struct list_head *devdrvs_list, FILE *devices_fp)
+#define READ_DEVICES_LINE_LEN 256
+static struct devdrv *read_devdrv(const char *line)
 {
 	unsigned long major;
-	char line[256];
-	char name[sizeof(line)];
+	char name[READ_DEVICES_LINE_LEN];
 
-	while (fgets(line, sizeof(line), devices_fp)) {
-		struct devdrv *devdrv;
+	if (sscanf(line, "%lu %s", &major, name) != 2)
+		return NULL;
+
+	return new_devdrv(major, name);
+}
 
+static void read_devices(struct list_head *chrdrvs_list,
+			 struct list_head *blkdrvs_list, FILE *devices_fp)
+{
+	char line[READ_DEVICES_LINE_LEN];
+
+	/* Skip to the line "Character devices:". */
+	while (fgets(line, sizeof(line), devices_fp)) {
 		if (line[0] == 'C')
-			continue; /* "Character devices:" */
-		else if (line[0] == '\n')
 			break;
+		continue;
+	}
 
-		if (sscanf(line, "%lu %s", &major, name) != 2)
-			continue;
-		devdrv = new_devdrv(major, name);
-		list_add_tail(&devdrv->devdrvs, devdrvs_list);
+	while (fgets(line, sizeof(line), devices_fp)) {
+		/* Find the blank line before "Block devices:" line. */
+		if (line[0] == '\n')
+			break;
+
+		/* Read the character device drivers */
+		struct devdrv *devdrv = read_devdrv(line);
+		if (devdrv)
+			list_add_tail(&devdrv->devdrvs, chrdrvs_list);
+	}
+
+	/* Skip to the line "Block devices:". */
+	while (fgets(line, sizeof(line), devices_fp)) {
+		if (line[0] == 'B')
+			break;
+		continue;
+	}
+
+	/* Read the block device drivers */
+	while (fgets(line, sizeof(line), devices_fp)) {
+		struct devdrv *devdrv = read_devdrv(line);
+		if (devdrv)
+			list_add_tail(&devdrv->devdrvs, blkdrvs_list);
 	}
 }
 
@@ -962,23 +992,25 @@ static void initialize_devdrvs(void)
 	FILE *devices_fp;
 
 	INIT_LIST_HEAD(&chrdrvs);
+	INIT_LIST_HEAD(&blkdrvs);
 
 	devices_fp = fopen("/proc/devices", "r");
 	if (devices_fp) {
-		read_devices(&chrdrvs, devices_fp);
+		read_devices(&chrdrvs, &blkdrvs, devices_fp);
 		fclose(devices_fp);
 	}
 }
 
 static void finalize_devdrvs(void)
 {
+	list_free(&blkdrvs, struct devdrv,  devdrvs, free_devdrv);
 	list_free(&chrdrvs, struct devdrv,  devdrvs, free_devdrv);
 }
 
-const char *get_chrdrv(unsigned long major)
+static const char *get_devdrv(struct list_head *devdrvs_list, unsigned long major)
 {
 	struct list_head *c;
-	list_for_each(c, &chrdrvs) {
+	list_for_each(c, devdrvs_list) {
 		struct devdrv *devdrv = list_entry(c, struct devdrv, devdrvs);
 		if (devdrv->major == major)
 			return devdrv->name;
@@ -986,6 +1018,16 @@ const char *get_chrdrv(unsigned long major)
 	return NULL;
 }
 
+const char *get_chrdrv(unsigned long major)
+{
+	return get_devdrv(&chrdrvs, major);
+}
+
+const char *get_blkdrv(unsigned long major)
+{
+	return get_devdrv(&blkdrvs, major);
+}
+
 struct name_manager *new_name_manager(void)
 {
 	struct name_manager *nm = xcalloc(1, sizeof(struct name_manager));
diff --git a/misc-utils/lsfd.h b/misc-utils/lsfd.h
index 9b0e3aef24..997687939c 100644
--- a/misc-utils/lsfd.h
+++ b/misc-utils/lsfd.h
@@ -151,6 +151,7 @@ const char *get_name(struct name_manager *nm, unsigned long id);
 unsigned long add_name(struct name_manager *nm, const char *name);
 
 const char *get_partition(dev_t dev);
+const char *get_blkdrv(unsigned long major);
 const char *get_chrdrv(unsigned long major);
 const char *get_miscdev(unsigned long minor);
 const char *get_nodev_filesystem(unsigned long minor);