libsensors: Report I/O errors as such.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4899 7894878c-1315-0410-8ee3-d5d059ff63e0

CHANGES

@@ -5,6 +5,7 @@ SVN
   Makefile: Add sensors-conf-convert to make install
   libsensors: Notify the caller when writing a value fails
               Differentiate between different read error types
+              Report I/O errors as such
   sensord: Log the error code on failure
   sensors: Fix spurious critical temperature alarm
            Print error messages to stderr

lib/error.c

@@ -42,6 +42,7 @@ static const char *errorlist[] = {
 	/* SENSORS_ERR_BUS_NAME  */ "Can't parse bus name",
 	/* SENSORS_ERR_PARSE     */ "General parse error",
 	/* SENSORS_ERR_ACCESS_W  */ "Can't write",
+	/* SENSORS_ERR_IO        */ "I/O error",
 };
 
 const char *sensors_strerror(int errnum)

lib/error.h

@@ -30,6 +30,7 @@
 #define SENSORS_ERR_BUS_NAME	7 /* Can't parse bus name */
 #define SENSORS_ERR_PARSE	8 /* General parse error */
 #define SENSORS_ERR_ACCESS_W	9 /* Can't write */
+#define SENSORS_ERR_IO		10 /* I/O error */
 
 #ifdef __cplusplus
 extern "C" {

lib/sysfs.c

@@ -557,9 +557,24 @@ int sensors_read_sysfs_attr(const sensors_chip_name *name,
 
 	snprintf(n, NAME_MAX, "%s/%s", name->path, subfeature->name);
 	if ((f = fopen(n, "r"))) {
-		int res = fscanf(f, "%lf", value);
-		if (fclose(f) || res != 1)
-			return -SENSORS_ERR_ACCESS_R;
+		int res, err = 0;
+
+		errno = 0;
+		res = fscanf(f, "%lf", value);
+		if (res == EOF && errno == EIO)
+			err = -SENSORS_ERR_IO;
+		else if (res != 1)
+			err = -SENSORS_ERR_ACCESS_R;
+		res = fclose(f);
+		if (err)
+			return err;
+
+		if (res == EOF) {
+			if (errno == EIO)
+				return -SENSORS_ERR_IO;
+			else 
+				return -SENSORS_ERR_ACCESS_R;
+		}
 		*value /= get_type_scaling(subfeature->type);
 	} else
 		return -SENSORS_ERR_KERNEL;
@@ -576,11 +591,24 @@ int sensors_write_sysfs_attr(const sensors_chip_name *name,
 
 	snprintf(n, NAME_MAX, "%s/%s", name->path, subfeature->name);
 	if ((f = fopen(n, "w"))) {
-		int res;
+		int res, err = 0;
+
 		value *= get_type_scaling(subfeature->type);
 		res = fprintf(f, "%d", (int) value);
-		if (fclose(f) || res < 0)
-			return -SENSORS_ERR_ACCESS_W;
+		if (res == -EIO)
+			err = -SENSORS_ERR_IO;
+		else if (res < 0)
+			err = -SENSORS_ERR_ACCESS_W;
+		res = fclose(f);
+		if (err)
+			return err;
+
+		if (res == EOF) {
+			if (errno == EIO)
+				return -SENSORS_ERR_IO;
+			else 
+				return -SENSORS_ERR_ACCESS_W;
+		}
 	} else
 		return -SENSORS_ERR_KERNEL;