From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: Re: [PATCH 4/6] target: Send UA on ALUA target port group change Date: Tue, 23 Jun 2015 00:54:24 -0700 Message-ID: <1435046064.7460.23.camel@haakon3.risingtidesystems.com> References: <1434009689-112909-1-git-send-email-hare@suse.de> <1434009689-112909-5-git-send-email-hare@suse.de> <20150619130519.GA7783@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150619130519.GA7783@lst.de> Sender: target-devel-owner@vger.kernel.org To: Christoph Hellwig Cc: Hannes Reinecke , Nic Bellinger , target-devel@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org 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. 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 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 Cc: Hannes Reinecke Signed-off-by: Nicholas Bellinger --- 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