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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: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
hifive-unleashed-5.1
Juergen Gross 2016-02-08 15:30:19 +01:00 committed by David Vrabel
parent f285aa8db7
commit c9e2f531be
1 changed files with 41 additions and 29 deletions
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70
drivers/xen/xen-scsiback.c
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@ -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;
@ -917,15 +933,10 @@ 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)) {
pr_warn("Virtual ID is already used. Assignment was not performed.\n");
err = -EEXIST;
goto out;
}
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 */
@ -933,7 +944,7 @@ static int scsiback_add_translation_entry(struct vscsibk_info *info,
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;
}
}
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 1;
found:
/* Delete the translation entry specfied */
__scsiback_del_translation_entry(entry);
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)) {