Commit c9e2f531 authored by Juergen Gross's avatar Juergen Gross Committed by David Vrabel
Browse files

xen/scsiback: avoid warnings when adding multiple LUNs to a domain 



When adding more than one LUN to a frontend a warning for a failed
assignment is issued in dom0 for each already existing LUN. Avoid this
warning by checking for a LUN already existing when existence is
allowed (scsiback_do_add_lun() called with try == 1).

As the LUN existence check is needed now for a third time, factor it
out into a function. This in turn leads to a more or less complete
rewrite of scsiback_del_translation_entry() which will now return a
proper error code in case of failure.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
parent f285aa8d

drivers/xen/xen-scsiback.c

+41 −29
Original line number Diff line number Diff line
@@ -848,6 +848,24 @@ static int scsiback_map(struct vscsibk_info *info) 
	return scsiback_init_sring(info, ring_ref, evtchn);

}



/*

  Check for a translation entry being present

*/

static struct v2p_entry *scsiback_chk_translation_entry(

	struct vscsibk_info *info, struct ids_tuple *v)

{

	struct list_head *head = &(info->v2p_entry_lists);

	struct v2p_entry *entry;



	list_for_each_entry(entry, head, l)

		if ((entry->v.chn == v->chn) &&

		    (entry->v.tgt == v->tgt) &&

		    (entry->v.lun == v->lun))

			return entry;



	return NULL;

}



/*

  Add a new translation entry

*/
@@ -855,9 +873,7 @@ static int scsiback_add_translation_entry(struct vscsibk_info *info, 
					  char *phy, struct ids_tuple *v)

{

	int err = 0;

	struct v2p_entry *entry;

	struct v2p_entry *new;

	struct list_head *head = &(info->v2p_entry_lists);

	unsigned long flags;

	char *lunp;

	unsigned long long unpacked_lun;
@@ -917,23 +933,18 @@ static int scsiback_add_translation_entry(struct vscsibk_info *info, 
	spin_lock_irqsave(&info->v2p_lock, flags);



	/* Check double assignment to identical virtual ID */

	list_for_each_entry(entry, head, l) {

		if ((entry->v.chn == v->chn) &&

		    (entry->v.tgt == v->tgt) &&

		    (entry->v.lun == v->lun)) {

	if (scsiback_chk_translation_entry(info, v)) {

		pr_warn("Virtual ID is already used. Assignment was not performed.\n");

		err = -EEXIST;

		goto out;

	}



	}



	/* Create a new translation entry and add to the list */

	kref_init(&new->kref);

	new->v = *v;

	new->tpg = tpg;

	new->lun = unpacked_lun;

	list_add_tail(&new->l, head);

	list_add_tail(&new->l, &info->v2p_entry_lists);



out:

	spin_unlock_irqrestore(&info->v2p_lock, flags);
@@ -956,39 +967,40 @@ static void __scsiback_del_translation_entry(struct v2p_entry *entry) 
}



/*

  Delete the translation entry specfied

  Delete the translation entry specified

*/

static int scsiback_del_translation_entry(struct vscsibk_info *info,

					  struct ids_tuple *v)

{

	struct v2p_entry *entry;

	struct list_head *head = &(info->v2p_entry_lists);

	unsigned long flags;

	int ret = 0;



	spin_lock_irqsave(&info->v2p_lock, flags);

	/* Find out the translation entry specified */

	list_for_each_entry(entry, head, l) {

		if ((entry->v.chn == v->chn) &&

		    (entry->v.tgt == v->tgt) &&

		    (entry->v.lun == v->lun)) {

			goto found;

		}

	}



	spin_unlock_irqrestore(&info->v2p_lock, flags);

	return 1;



found:

	/* Delete the translation entry specfied */

	entry = scsiback_chk_translation_entry(info, v);

	if (entry)

		__scsiback_del_translation_entry(entry);

	else

		ret = -ENOENT;



	spin_unlock_irqrestore(&info->v2p_lock, flags);

	return 0;

	return ret;

}



static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,

				char *phy, struct ids_tuple *vir, int try)

{

	struct v2p_entry *entry;

	unsigned long flags;



	if (try) {

		spin_lock_irqsave(&info->v2p_lock, flags);

		entry = scsiback_chk_translation_entry(info, vir);

		spin_unlock_irqrestore(&info->v2p_lock, flags);

		if (entry)

			return;

	}

	if (!scsiback_add_translation_entry(info, phy, vir)) {

		if (xenbus_printf(XBT_NIL, info->dev->nodename, state,

				  "%d", XenbusStateInitialised)) {

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