sysfs: functions for writing md/<memb>/state

Add dedicated enum to reflect possible values for mentioned file.
Not all values are mapped. Add map to present sysfs keywords.

Signed-off-by: Mariusz Tkaczyk <[email protected]>

Manage.c

@@ -1675,9 +1675,7 @@ int Manage_subdevs(char *devname, int fd,
 			}
 		case 'I':
 			if (is_fd_valid(sysfd)) {
-				static const char val[] = "faulty";
-
-				rv = sysfs_write_descriptor(sysfd, val, strlen(val), &err);
+				rv = sysfs_set_memb_state_fd(sysfd, MEMB_STATE_FAULTY, &err);
 			} else {
 				rv = ioctl(fd, SET_DISK_FAULTY, rdev);
 				if (rv)

mdadm.h

@@ -807,9 +807,28 @@ enum sysfs_read_flags {
 
 #define SYSFS_MAX_BUF_SIZE 64
 
+/**
+ * Defines md/<disk>/state possible values.
+ * Note that remove can't be read-back from the file.
+ *
+ * This is not complete list.
+ */
+typedef enum memb_state {
+	MEMB_STATE_EXTERNAL_BBL,
+	MEMB_STATE_BLOCKED,
+	MEMB_STATE_SPARE,
+	MEMB_STATE_WRITE_MOSTLY,
+	MEMB_STATE_IN_SYNC,
+	MEMB_STATE_FAULTY,
+	MEMB_STATE_REMOVE,
+	MEMB_STATE_UNKNOWN
+} memb_state_t;
+char *map_memb_state(memb_state_t state);
+
 extern mdadm_status_t sysfs_write_descriptor(const int fd, const char *value,
 					     const ssize_t len, int *errno_p);
 extern mdadm_status_t write_attr(const char *value, const int fd);
+extern mdadm_status_t sysfs_set_memb_state_fd(int fd, memb_state_t state, int *err);
 extern void sysfs_get_container_devnm(struct mdinfo *mdi, char *buf);
 
 extern int sysfs_open(char *devnm, char *devname, char *attr);

monitor.c

@@ -140,17 +140,17 @@ int read_dev_state(int fd)
 
 	cp = buf;
 	while (cp) {
-		if (sysfs_attr_match(cp, "faulty"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_FAULTY)))
 			rv |= DS_FAULTY;
-		if (sysfs_attr_match(cp, "in_sync"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_IN_SYNC)))
 			rv |= DS_INSYNC;
-		if (sysfs_attr_match(cp, "write_mostly"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_WRITE_MOSTLY)))
 			rv |= DS_WRITE_MOSTLY;
-		if (sysfs_attr_match(cp, "spare"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_SPARE)))
 			rv |= DS_SPARE;
-		if (sysfs_attr_match(cp, "blocked"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_BLOCKED)))
 			rv |= DS_BLOCKED;
-		if (sysfs_attr_match(cp, "external_bbl"))
+		if (sysfs_attr_match(cp, map_memb_state(MEMB_STATE_EXTERNAL_BBL)))
 			rv |= DS_EXTERNAL_BB;
 		cp = strchr(cp, ',');
 		if (cp)

sysfs.c

@@ -75,6 +75,23 @@ void sysfs_free(struct mdinfo *sra)
 		sra = sra2;
 	}
 }
+
+mapping_t sysfs_memb_states[] = {
+	{"external_bbl", MEMB_STATE_EXTERNAL_BBL},
+	{"blocked", MEMB_STATE_BLOCKED},
+	{"spare", MEMB_STATE_SPARE},
+	{"write_mostly", MEMB_STATE_WRITE_MOSTLY},
+	{"in_sync", MEMB_STATE_IN_SYNC},
+	{"faulty", MEMB_STATE_FAULTY},
+	{"remove",  MEMB_STATE_REMOVE},
+	{NULL,  MEMB_STATE_UNKNOWN}
+};
+
+char *map_memb_state(memb_state_t state)
+{
+	return map_num_s(sysfs_memb_states, state);
+}
+
 /**
  * write_attr() - write value to fd, don't check errno.
  * @attr: value to write.
@@ -117,6 +134,21 @@ mdadm_status_t sysfs_write_descriptor(const int fd, const char *value, const ssi
 	return MDADM_STATUS_SUCCESS;
 }
 
+/**
+ * sysfs_set_memb_state_fd() - write to md/<memb>/state file.
+ * @fd: open file descriptor to the file.
+ * @state: enum value describing value to write
+ * @err: errno value pointer in case of error.
+ *
+ * This is helper to avoid inlining values, they are extracted from map now.
+ */
+mdadm_status_t sysfs_set_memb_state_fd(int fd, memb_state_t state, int *err)
+{
+	const char *val = map_memb_state(state);
+
+	return sysfs_write_descriptor(fd, val, strlen(val), err);
+}
+
 /**
  * sysfs_get_container_devnm() - extract container device name.
  * @mdi: md_info describes member array, with GET_VERSION option.

util.c

@@ -1808,12 +1808,11 @@ int hot_remove_disk(int mdfd, unsigned long dev, int force)
 
 int sys_hot_remove_disk(int statefd, int force)
 {
-	static const char val[] = "remove";
 	int cnt = force ? 500 : 5;
 
 	while (cnt--) {
 		int err = 0;
-		int ret = sysfs_write_descriptor(statefd, val, strlen(val), &err);
+		int ret = sysfs_set_memb_state_fd(statefd, MEMB_STATE_REMOVE, &err);
 
 		if (ret == MDADM_STATUS_SUCCESS)
 			return 0;