Commit 82f29467 authored by Mike Anderson's avatar Mike Anderson Committed by James Bottomley
Browse files

[SCSI] host state model update: mediate host add/remove race 



Add support to not allow additions to a host when it is being removed.

Signed-off-by: default avatarMike Anderson <andmike@us.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent d2c9d9ea

drivers/scsi/hosts.c

+2 −0
Original line number Diff line number Diff line
@@ -133,7 +133,9 @@ EXPORT_SYMBOL(scsi_host_set_state); 
 **/

void scsi_remove_host(struct Scsi_Host *shost)

{

	down(&shost->scan_mutex);

	scsi_host_set_state(shost, SHOST_CANCEL);

	up(&shost->scan_mutex);

	scsi_forget_host(shost);

	scsi_proc_host_rm(shost);

drivers/scsi/scsi_scan.c

+14 −7
Original line number Diff line number Diff line
@@ -1251,9 +1251,12 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 


	get_device(&starget->dev);

	down(&shost->scan_mutex);

	res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);

	if (scsi_host_scan_allowed(shost)) {

		res = scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1,

					     hostdata);

		if (res != SCSI_SCAN_LUN_PRESENT)

			sdev = ERR_PTR(-ENODEV);

	}

	up(&shost->scan_mutex);

	scsi_target_reap(starget);

	put_device(&starget->dev);
@@ -1403,11 +1406,15 @@ int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 
		return -EINVAL;



	down(&shost->scan_mutex);

	if (scsi_host_scan_allowed(shost)) {

		if (channel == SCAN_WILD_CARD)

		for (channel = 0; channel <= shost->max_channel; channel++)

			scsi_scan_channel(shost, channel, id, lun, rescan);

			for (channel = 0; channel <= shost->max_channel;

			     channel++)

				scsi_scan_channel(shost, channel, id, lun,

						  rescan);

		else

			scsi_scan_channel(shost, channel, id, lun, rescan);

	}

	up(&shost->scan_mutex);



	return 0;

include/scsi/scsi_host.h

+9 −0
Original line number Diff line number Diff line
@@ -650,6 +650,15 @@ static inline struct device *scsi_get_device(struct Scsi_Host *shost) 
        return shost->shost_gendev.parent;

}



/**

 * scsi_host_scan_allowed - Is scanning of this host allowed

 * @shost:	Pointer to Scsi_Host.

 **/

static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)

{

	return shost->shost_state == SHOST_RUNNING;

}



extern void scsi_unblock_requests(struct Scsi_Host *);

extern void scsi_block_requests(struct Scsi_Host *);