iprutils: Unbind device before JBOD -> AF formatting.

Introducing a new function for binding and unbinding a JBOD device, which is
used before formatting and in case we need to rollback because of a
failure. This prevents overlength errors when a read is issued to the disk
during formatting.

Changes since v1:
- Added two missing close() to ipr_jbod_sysfs_bind()

Signed-off-by: Heitor Ricardo Alves de Siqueira <halves@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>

iprconfig.c

@@ -8862,12 +8862,23 @@ int send_dev_inits(i_container *i_con)
 				continue;
 			}
 
+			/* unbind device */
+			if (ipr_jbod_sysfs_bind(cur_dev_init->dev,
+						IPR_JBOD_SYSFS_UNBIND))
+				syslog(LOG_ERR, "Could not unbind %s: %m\n",
+				       cur_dev_init->dev->dev_name);
+
 			/* Issue format */
 			status = ipr_format_unit(cur_dev_init->dev);  /* FIXME  Mandatory lock? */   
 
 			if (status) {
 				/* Send a device reset to cleanup any old state */
 				rc = ipr_reset_device(cur_dev_init->dev);
+				if (ipr_jbod_sysfs_bind(cur_dev_init->dev,
+							IPR_JBOD_SYSFS_BIND))
+					syslog(LOG_ERR,
+					       "Could not bind %s: %m\n",
+					       cur_dev_init->dev->dev_name);
 
 				cur_dev_init->do_init = 0;
 				num_devs--;

iprlib.c

@@ -10031,3 +10031,51 @@ int ipr_query_io_dev_port(struct ipr_dev *dev, struct ipr_query_io_port *io_port
 	return rc;
 }
 
+/**
+ * ipr_jbod_sysfs_bind -
+ * @dev:		ipr dev struct
+ * @op:			sysfs operation
+ *
+ * Returns:
+ *   0 if success / non-zero on failure
+ **/
+int ipr_jbod_sysfs_bind(struct ipr_dev *dev, u8 op)
+{
+	struct ipr_dev *mp_dev;
+	int rc, fd, size;
+	char *sysfs_device_name;
+
+	sysfs_device_name = dev->scsi_dev_data->sysfs_device_name;
+	size = strnlen(sysfs_device_name, sizeof(sysfs_device_name));
+
+	if (op == IPR_JBOD_SYSFS_BIND) {
+		fd = open("/sys/bus/scsi/drivers/sd/bind", O_WRONLY);
+	} else if (op == IPR_JBOD_SYSFS_UNBIND) {
+		fd = open("/sys/bus/scsi/drivers/sd/unbind", O_WRONLY);
+	} else {
+		fd = -1;
+		errno = ENOTSUP;
+	}
+	if (fd < 0)
+		return errno;
+
+	rc = write(fd, sysfs_device_name, size);
+	if (rc < 0) {
+		close(fd);
+		return errno;
+	}
+
+	mp_dev = find_multipath_jbod(dev);
+	if (mp_dev) {
+		sysfs_device_name = mp_dev->scsi_dev_data->sysfs_device_name;
+		size = strnlen(sysfs_device_name, sizeof(sysfs_device_name));
+		rc = write(fd, sysfs_device_name, size);
+		if (rc < 0) {
+			close(fd);
+			return errno;
+		}
+	}
+
+	close(fd);
+	return 0;
+}

iprlib.h

@@ -1321,6 +1321,9 @@ struct ipr_mode_page_28_scsi_dev_bus_attr {
 #define IPR_MAX_XFER_RATE 320
 #define IPR_SAFE_XFER_RATE 160
 
+#define IPR_JBOD_SYSFS_UNBIND 0
+#define IPR_JBOD_SYSFS_BIND   1
+
 /* Internal return codes */
 #define RC_SUCCESS          0
 #define RC_FAILED          -1