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author | Juergen Gross <jgross@suse.com> | 2016-02-08 15:30:19 +0100 |
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committer | David Vrabel <david.vrabel@citrix.com> | 2016-02-08 16:51:36 +0000 |
commit | c9e2f531be000af652927ee0af3a0f24f8e9e046 (patch) | |
tree | 8bcf8cefe2dd2c80cfbf9d6a9c627aef2c63cc8c /drivers/xen/xen-scsiback.c | |
parent | f285aa8db7cc4432c1a03f8b55ff34fe96317c11 (diff) | |
download | op-kernel-dev-c9e2f531be000af652927ee0af3a0f24f8e9e046.zip op-kernel-dev-c9e2f531be000af652927ee0af3a0f24f8e9e046.tar.gz |
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>
Diffstat (limited to 'drivers/xen/xen-scsiback.c')
-rw-r--r-- | drivers/xen/xen-scsiback.c | 70 |
1 files 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)) { |