Chandra Seetharaman wrote:
On Wed, 2008-05-14 at 16:43 +0200, Hannes Reinecke wrote:Implement a 'dh_state' sdev attribute for dynamic device handler manipulation. A read on the attribute will return the name of the currently attached device handler or 'detached' if no handler is attached. The attribute allows the following strings to be written: - The name of the device handler to be attached if the state is 'detached'. - 'activate' to trigger path activation if a device handler is attached. - 'detach' to detach the currently attached device handler. Signed-off-by: Hannes Reinecke <hare suse de> ---All the sysfs functions can be grouped together. Helps in readability.
?? But I did ... Or thought so, anyway. Checking.
drivers/scsi/device_handler/scsi_dh.c | 88 +++++++++++++++++++++++++++++++++ 1 files changed, 88 insertions(+), 0 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c index 55e5fd2..2dbf84b 100644 --- a/drivers/scsi/device_handler/scsi_dh.c +++ b/drivers/scsi/device_handler/scsi_dh.c @@ -54,6 +54,55 @@ static struct scsi_device_handler *get_device_handler(const char *name) return found; } +static ssize_t +store_dh_state(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct scsi_device *sdev = to_scsi_device(dev); + struct scsi_device_handler *scsi_dh; + int err = -EINVAL; + + if (!sdev->scsi_dh_data) { + /* + * Attach to a device handler+ */ + if (!(scsi_dh = get_device_handler(buf)))+ return err; + err = scsi_dh_handler_attach(sdev, scsi_dh); + } else { + /* + * Detach from a device handler + */ + if (!strncmp(buf, "detach", 6)) { + err = scsi_dh_handler_detach(sdev); + } else if (!strncmp(buf, "activate", 8)) { + scsi_dh = sdev->scsi_dh_data->scsi_dh; + + err = scsi_dh->activate(sdev); + } + } + + return err<0?err:count; +} + +static ssize_t +show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct scsi_device *sdev = to_scsi_device(dev); + struct scsi_device_handler *scsi_dh; + + if (!sdev->scsi_dh_data) + return snprintf(buf, 20, "detached\n"); + + scsi_dh = sdev->scsi_dh_data->scsi_dh;we can use it directly instead of this variable ?
Yes.
+ + return snprintf(buf, 20, "%s\n", scsi_dh->name); +} + +static struct device_attribute scsi_dh_state_attr = + __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, + store_dh_state); + /* * scsi_dh_handler_attach - Attach a device handler to a device * @sdev - SCSI device the device handler should attach to @@ -115,9 +164,11 @@ static int scsi_dh_notifier(struct notifier_block *nb, if (action == BUS_NOTIFY_ADD_DEVICE) { scsi_dh_handler_attach(sdev, devinfo->handler); + device_create_file(dev, &scsi_dh_state_attr);A later patch checks for the return status of scsi_dh_handler_attach(), should be moved here.
Ok. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare suse de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg)