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@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
v2: scsiback_del_translation_entry() returns error code instead of 1
(Boris Ostrovsky)
---
drivers/xen/xen-scsiback.c | 70 +++++++++++++++++++++++++++-------------------
1 file changed, 41 insertions(+), 29 deletions(-)
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 51387d7..c46ee18 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -849,15 +849,31 @@ static int scsiback_map(struct vscsibk_info *info)
}
/*
+ 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
*/
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;
- }
- }
-
- spin_unlock_irqrestore(&info->v2p_lock, flags);
- return 1;
-
-found:
- /* Delete the translation entry specfied */
- __scsiback_del_translation_entry(entry);
+ 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)) {
--
2.6.2
--
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