On Fri, 2015-06-19 at 15:05 +0200, Christoph Hellwig wrote:
> > --- a/drivers/target/target_core_alua.c
> > +++ b/drivers/target/target_core_alua.c
> > @@ -1880,12 +1880,19 @@ static void core_alua_put_tg_pt_gp_from_name(
> > static void __target_attach_tg_pt_gp(struct se_lun *lun,
> > struct t10_alua_tg_pt_gp *tg_pt_gp)
> > {
> > + struct se_dev_entry *se_deve;
> > +
> > assert_spin_locked(&lun->lun_tg_pt_gp_lock);
> >
> > spin_lock(&tg_pt_gp->tg_pt_gp_lock);
> > lun->lun_tg_pt_gp = tg_pt_gp;
> > list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
> > tg_pt_gp->tg_pt_gp_members++;
> > + spin_lock_bh(&lun->lun_deve_lock);
> > + list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
> > + core_scsi3_ua_allocate(se_deve, 0x3f,
> > + ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
> > + spin_unlock_bh(&lun->lun_deve_lock);
> > spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
>
> Taking a _bh lock inside a regular spinlock is completely broken.
>
...
> Fortunately I don't think lun_deve_lock needs to disable bottom halves,
> but this needs to be fixed first.
<nod>
Applying the following + updating this original patch to use normal
spinlock_t access.
>From 1adff1b3a7f75a1c255b7fcab5676edf29d4a5d8 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Date: Mon, 22 Jun 2015 23:44:05 -0700
Subject: [PATCH 65/76] target: Convert se_lun->lun_deve_lock to normal
spinlock
This patch converts se_lun->lun_deve_lock acquire/release access
to use a normal, non bottom-half spin_lock_t for protecting
se_lun->lun_deve_list access.
Reported-by: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_alua.c | 4 ++--
drivers/target/target_core_device.c | 12 ++++++------
drivers/target/target_core_pr.c | 8 ++++----
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index aa2e4b1..c56ae02 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -968,7 +968,7 @@ static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
continue;
spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
- spin_lock_bh(&lun->lun_deve_lock);
+ spin_lock(&lun->lun_deve_lock);
list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
lacl = rcu_dereference_check(se_deve->se_lun_acl,
lockdep_is_held(&lun->lun_deve_lock));
@@ -1000,7 +1000,7 @@ static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
core_scsi3_ua_allocate(se_deve, 0x2A,
ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
}
- spin_unlock_bh(&lun->lun_deve_lock);
+ spin_unlock(&lun->lun_deve_lock);
spin_lock(&tg_pt_gp->tg_pt_gp_lock);
percpu_ref_put(&lun->lun_ref);
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index ed08402..b6df5b9 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -352,10 +352,10 @@ int core_enable_device_list_for_node(
hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
mutex_unlock(&nacl->lun_entry_mutex);
- spin_lock_bh(&lun->lun_deve_lock);
+ spin_lock(&lun->lun_deve_lock);
list_del(&orig->lun_link);
list_add_tail(&new->lun_link, &lun->lun_deve_list);
- spin_unlock_bh(&lun->lun_deve_lock);
+ spin_unlock(&lun->lun_deve_lock);
kref_put(&orig->pr_kref, target_pr_kref_release);
wait_for_completion(&orig->pr_comp);
@@ -369,9 +369,9 @@ int core_enable_device_list_for_node(
hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
mutex_unlock(&nacl->lun_entry_mutex);
- spin_lock_bh(&lun->lun_deve_lock);
+ spin_lock(&lun->lun_deve_lock);
list_add_tail(&new->lun_link, &lun->lun_deve_list);
- spin_unlock_bh(&lun->lun_deve_lock);
+ spin_unlock(&lun->lun_deve_lock);
return 0;
}
@@ -403,9 +403,9 @@ void core_disable_device_list_for_node(
* NodeACL context specific PR metadata for demo-mode
* MappedLUN *deve will be released below..
*/
- spin_lock_bh(&lun->lun_deve_lock);
+ spin_lock(&lun->lun_deve_lock);
list_del(&orig->lun_link);
- spin_unlock_bh(&lun->lun_deve_lock);
+ spin_unlock(&lun->lun_deve_lock);
/*
* Disable struct se_dev_entry LUN ACL mapping
*/
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 0bb3292..7403b03 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -709,7 +709,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
continue;
spin_unlock(&dev->se_port_lock);
- spin_lock_bh(&lun_tmp->lun_deve_lock);
+ spin_lock(&lun_tmp->lun_deve_lock);
list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
/*
* This pointer will be NULL for demo mode MappedLUNs
@@ -742,7 +742,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
continue;
kref_get(&deve_tmp->pr_kref);
- spin_unlock_bh(&lun_tmp->lun_deve_lock);
+ spin_unlock(&lun_tmp->lun_deve_lock);
/*
* Grab a configfs group dependency that is released
* for the exception path at label out: below, or upon
@@ -779,9 +779,9 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
&pr_reg->pr_reg_atp_list);
- spin_lock_bh(&lun_tmp->lun_deve_lock);
+ spin_lock(&lun_tmp->lun_deve_lock);
}
- spin_unlock_bh(&lun_tmp->lun_deve_lock);
+ spin_unlock(&lun_tmp->lun_deve_lock);
spin_lock(&dev->se_port_lock);
percpu_ref_put(&lun_tmp->lun_ref);
--
1.9.1
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