| Message ID | 1502061849.22966.44.camel@haakon3.daterainc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Aug 6, 2017 at 4:24 PM, Nicholas A. Bellinger <nab@linux-iscsi.org> wrote: > On Mon, 2017-07-31 at 14:48 -0700, Justin Maggard wrote: >> On Sun, Jul 30, 2017 at 5:15 PM, Nicholas A. Bellinger >> <nab@linux-iscsi.org> wrote: >> > On Thu, 2017-07-27 at 13:56 -0700, Justin Maggard wrote: >> >> I ran across a GPF after disabling demo-mode on an iSCSI target. The >> >> backtrace pointed to target_put_nacl(), which was called from >> >> transport_free_session(). >> > >> > Can we see actual stack trace, and kernel version please..? >> > >> >> Sure. > > <SNIP> > >> Thanks a lot, that clears up my misunderstanding. I should have read >> the kref documentation carefully first. >> >> So it looks like what's *really* happening is, >> transport_free_session() does a list_del(acl_list). At least in my >> case, this empties the list. Then, target_put_nacl() calls >> target_complete_nacl(), which also does a list_del(acl_list) and >> crashes. >> > > Ugh. I seem to recall the initial version of this patch was using > list_del_init(), but review feedback listed in commit 01d4d6735589 > shows that it was dropped as unnecessary: > > (Drop unnecessary list_del_init usage - HCH) > > Note the scenario in question is specific to generate_node_acls = 1 + > cache_dynamic_acls = 0. > > Here's the patch I'm applying to target-pending/master, with a CC' to > v4.1.y stable. > > Please verify on your end. > > Thank you. > Yes, that takes care of the issue for me. Thanks! Tested-by: Justin Maggard <jmaggard10@gmail.com> > From 73f6806a8124357ca00fcadaa9d58f617e44947e Mon Sep 17 00:00:00 2001 > From: Nicholas Bellinger <nab@linux-iscsi.org> > Date: Sun, 6 Aug 2017 16:10:03 -0700 > Subject: [PATCH] target: Fix node_acl demo-mode + uncached dynamic shutdown > regression > > This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0 > regression, that was introduced by > > commit 01d4d673558985d9a118e1e05026633c3e2ade9b > Author: Nicholas Bellinger <nab@linux-iscsi.org> > Date: Wed Dec 7 12:55:54 2016 -0800 > > which originally had the proper list_del_init() usage, but was > dropped during list review as it was thought unnecessary by HCH. > > However, list_del_init() usage is required during the special > generate_node_acls = 1 + cache_dynamic_acls = 0 case when > transport_free_session() does a list_del(&se_nacl->acl_list), > followed by target_complete_nacl() doing the same thing. > > This was manifesting as a general protection fault as reported > by Justin: > > kernel: general protection fault: 0000 [#1] SMP > kernel: Modules linked in: > kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20 > kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014 > kernel: task: ffff88026939e800 task.stack: ffffc90007884000 > kernel: RIP: 0010:target_put_nacl+0x49/0xb0 > kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246 > kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000 > kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028 > kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000 > kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020 > kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540 > kernel: FS: 0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000 > kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0 > kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > kernel: Call Trace: > kernel: transport_free_session+0x67/0x140 > kernel: transport_deregister_session+0x7a/0xc0 > kernel: iscsit_close_session+0x92/0x210 > kernel: iscsit_close_connection+0x5f9/0x840 > kernel: iscsit_take_action_for_connection_exit+0xfe/0x110 > kernel: iscsi_target_tx_thread+0x140/0x1e0 > kernel: ? wait_woken+0x90/0x90 > kernel: kthread+0x124/0x160 > kernel: ? iscsit_thread_get_cpumask+0x90/0x90 > kernel: ? kthread_create_on_node+0x40/0x40 > kernel: ret_from_fork+0x22/0x30 > kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c > 89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89 > ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20 > kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70 > kernel: ---[ end trace f12821adbfd46fed ]--- > > To address this, go ahead and use proper list_del_list() for all > cases of se_nacl->acl_list deletion. > > Reported-by: Justin Maggard <jmaggard01@gmail.com> > Cc: Justin Maggard <jmaggard01@gmail.com> > Cc: stable@vger.kernel.org # 4.1+ > Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> > --- > drivers/target/target_core_tpg.c | 4 ++-- > drivers/target/target_core_transport.c | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c > index 3691373..02e8a5d 100644 > --- a/drivers/target/target_core_tpg.c > +++ b/drivers/target/target_core_tpg.c > @@ -364,7 +364,7 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl) > mutex_lock(&tpg->acl_node_mutex); > if (acl->dynamic_node_acl) > acl->dynamic_node_acl = 0; > - list_del(&acl->acl_list); > + list_del_init(&acl->acl_list); > mutex_unlock(&tpg->acl_node_mutex); > > target_shutdown_sessions(acl); > @@ -548,7 +548,7 @@ int core_tpg_deregister(struct se_portal_group *se_tpg) > * in transport_deregister_session(). > */ > list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) { > - list_del(&nacl->acl_list); > + list_del_init(&nacl->acl_list); > > core_tpg_wait_for_nacl_pr_ref(nacl); > core_free_device_list_for_node(nacl, se_tpg); > diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c > index 97fed9a..836d552 100644 > --- a/drivers/target/target_core_transport.c > +++ b/drivers/target/target_core_transport.c > @@ -466,7 +466,7 @@ static void target_complete_nacl(struct kref *kref) > } > > mutex_lock(&se_tpg->acl_node_mutex); > - list_del(&nacl->acl_list); > + list_del_init(&nacl->acl_list); > mutex_unlock(&se_tpg->acl_node_mutex); > > core_tpg_wait_for_nacl_pr_ref(nacl); > @@ -538,7 +538,7 @@ void transport_free_session(struct se_session *se_sess) > spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags); > > if (se_nacl->dynamic_stop) > - list_del(&se_nacl->acl_list); > + list_del_init(&se_nacl->acl_list); > } > mutex_unlock(&se_tpg->acl_node_mutex); > -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index 3691373..02e8a5d 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -364,7 +364,7 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl) mutex_lock(&tpg->acl_node_mutex); if (acl->dynamic_node_acl) acl->dynamic_node_acl = 0; - list_del(&acl->acl_list); + list_del_init(&acl->acl_list); mutex_unlock(&tpg->acl_node_mutex); target_shutdown_sessions(acl); @@ -548,7 +548,7 @@ int core_tpg_deregister(struct se_portal_group *se_tpg) * in transport_deregister_session(). */ list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) { - list_del(&nacl->acl_list); + list_del_init(&nacl->acl_list); core_tpg_wait_for_nacl_pr_ref(nacl); core_free_device_list_for_node(nacl, se_tpg); diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 97fed9a..836d552 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -466,7 +466,7 @@ static void target_complete_nacl(struct kref *kref) } mutex_lock(&se_tpg->acl_node_mutex); - list_del(&nacl->acl_list); + list_del_init(&nacl->acl_list); mutex_unlock(&se_tpg->acl_node_mutex); core_tpg_wait_for_nacl_pr_ref(nacl); @@ -538,7 +538,7 @@ void transport_free_session(struct se_session *se_sess) spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags); if (se_nacl->dynamic_stop) - list_del(&se_nacl->acl_list); + list_del_init(&se_nacl->acl_list); } mutex_unlock(&se_tpg->acl_node_mutex);