lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[SCSI] scsi_dh: attach to hardware handler from dm-mpath

Browse Source 
multipath keeps a separate device table which may be
more current than the built-in one.
So we should make sure to always call ->attach whenever
a multipath map with hardware handler is instantiated.
And we should call ->detach on removal, too.

[sekharan: update as per comments from agk]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Hannes Reinecke
2008-07-17 17:49:02 -07:00
committed by James Bottomley
parent 057ea7c968
commit ae11b1b36d
3 changed files with 87 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
drivers/scsi/device_handler/scsi_dh.c
View File

@@ -369,6 +369,70 @@ int scsi_dh_handler_exist(const char *name)
}
EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
/*
* scsi_dh_handler_attach - Attach device handler
* @sdev - sdev the handler should be attached to
* @name - name of the handler to attach
*/
int scsi_dh_attach(struct request_queue *q, const char *name)
{
unsigned long flags;
struct scsi_device *sdev;
struct scsi_device_handler *scsi_dh;
int err = 0;
scsi_dh = get_device_handler(name);
if (!scsi_dh)
return -EINVAL;
spin_lock_irqsave(q->queue_lock, flags);
sdev = q->queuedata;
if (!sdev || !get_device(&sdev->sdev_gendev))
err = -ENODEV;
spin_unlock_irqrestore(q->queue_lock, flags);
if (!err) {
err = scsi_dh_handler_attach(sdev, scsi_dh);
put_device(&sdev->sdev_gendev);
}
return err;
}
EXPORT_SYMBOL_GPL(scsi_dh_attach);
/*
* scsi_dh_handler_detach - Detach device handler
* @sdev - sdev the handler should be detached from
*
* This function will detach the device handler only
* if the sdev is not part of the internal list, ie
* if it has been attached manually.
*/
void scsi_dh_detach(struct request_queue *q)
{
unsigned long flags;
struct scsi_device *sdev;
struct scsi_device_handler *scsi_dh = NULL;
spin_lock_irqsave(q->queue_lock, flags);
sdev = q->queuedata;
if (!sdev || !get_device(&sdev->sdev_gendev))
sdev = NULL;
spin_unlock_irqrestore(q->queue_lock, flags);
if (!sdev)
return;
if (sdev->scsi_dh_data) {
/* if sdev is not on internal list, detach */
scsi_dh = sdev->scsi_dh_data->scsi_dh;
if (!device_handler_match(scsi_dh, sdev))
scsi_dh_handler_detach(sdev, scsi_dh);
}
put_device(&sdev->sdev_gendev);
}
EXPORT_SYMBOL_GPL(scsi_dh_detach);
static struct notifier_block scsi_dh_nb = {
.notifier_call = scsi_dh_notifier
};