* [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-11 23:10 ` Dan Williams
0 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-11 23:10 UTC (permalink / raw)
To: linux-nvdimm; +Cc: linux-kernel, stable
The following warning results from holding a lane spinlock,
preempt_disable(), or the btt map spinlock and then trying to take the
reconfig_mutex to walk the poison list and potentially add new entries.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
in_atomic(): 1, irqs_disabled(): 0, pid: 17159, name: dd
[..]
Call Trace:
dump_stack+0x85/0xc8
___might_sleep+0x184/0x250
__might_sleep+0x4a/0x90
__mutex_lock+0x58/0x9b0
? nvdimm_bus_lock+0x21/0x30 [libnvdimm]
? __nvdimm_bus_badblocks_clear+0x2f/0x60 [libnvdimm]
? acpi_nfit_forget_poison+0x79/0x80 [nfit]
? _raw_spin_unlock+0x27/0x40
mutex_lock_nested+0x1b/0x20
nvdimm_bus_lock+0x21/0x30 [libnvdimm]
nvdimm_forget_poison+0x25/0x50 [libnvdimm]
nvdimm_clear_poison+0x106/0x140 [libnvdimm]
nsio_rw_bytes+0x164/0x270 [libnvdimm]
btt_write_pg+0x1de/0x3e0 [nd_btt]
? blk_queue_enter+0x30/0x290
btt_make_request+0x11a/0x310 [nd_btt]
? blk_queue_enter+0xb7/0x290
? blk_queue_enter+0x30/0x290
generic_make_request+0x118/0x3b0
As a minimal fix, disable error clearing when the BTT is enabled for the
namespace. For the final fix a larger rework of the poison list locking
is needed.
Note that this is not a problem in the blk case since that path never
calls nvdimm_clear_poison().
Cc: <stable@vger.kernel.org>
Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem")
Cc: Dave Jiang <dave.jiang@intel.com>
[jeff: dynamically disable error clearing in the btt case]
Suggested-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
v2: check for btt at run time rather than compile time (Jeff)
drivers/nvdimm/claim.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index b3323c0697f6..ca6d572c48fc 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -243,7 +243,15 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
- if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) {
+ /*
+ * FIXME: nsio_rw_bytes() may be called from atomic
+ * context in the btt case and nvdimm_clear_poison()
+ * takes a sleeping lock. Until the locking can be
+ * reworked this capability requires that the namespace
+ * is not claimed by btt.
+ */
+ if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+ && (!ndns->claim || !is_nd_btt(ndns->claim))) {
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev, offset, size);
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-11 23:10 ` Dan Williams
0 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-11 23:10 UTC (permalink / raw)
To: linux-nvdimm; +Cc: Vishal Verma, Jeff Moyer, Dave Jiang, linux-kernel, stable
The following warning results from holding a lane spinlock,
preempt_disable(), or the btt map spinlock and then trying to take the
reconfig_mutex to walk the poison list and potentially add new entries.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
in_atomic(): 1, irqs_disabled(): 0, pid: 17159, name: dd
[..]
Call Trace:
dump_stack+0x85/0xc8
___might_sleep+0x184/0x250
__might_sleep+0x4a/0x90
__mutex_lock+0x58/0x9b0
? nvdimm_bus_lock+0x21/0x30 [libnvdimm]
? __nvdimm_bus_badblocks_clear+0x2f/0x60 [libnvdimm]
? acpi_nfit_forget_poison+0x79/0x80 [nfit]
? _raw_spin_unlock+0x27/0x40
mutex_lock_nested+0x1b/0x20
nvdimm_bus_lock+0x21/0x30 [libnvdimm]
nvdimm_forget_poison+0x25/0x50 [libnvdimm]
nvdimm_clear_poison+0x106/0x140 [libnvdimm]
nsio_rw_bytes+0x164/0x270 [libnvdimm]
btt_write_pg+0x1de/0x3e0 [nd_btt]
? blk_queue_enter+0x30/0x290
btt_make_request+0x11a/0x310 [nd_btt]
? blk_queue_enter+0xb7/0x290
? blk_queue_enter+0x30/0x290
generic_make_request+0x118/0x3b0
As a minimal fix, disable error clearing when the BTT is enabled for the
namespace. For the final fix a larger rework of the poison list locking
is needed.
Note that this is not a problem in the blk case since that path never
calls nvdimm_clear_poison().
Cc: <stable@vger.kernel.org>
Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem")
Cc: Dave Jiang <dave.jiang@intel.com>
[jeff: dynamically disable error clearing in the btt case]
Suggested-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
v2: check for btt at run time rather than compile time (Jeff)
drivers/nvdimm/claim.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index b3323c0697f6..ca6d572c48fc 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -243,7 +243,15 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
- if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) {
+ /*
+ * FIXME: nsio_rw_bytes() may be called from atomic
+ * context in the btt case and nvdimm_clear_poison()
+ * takes a sleeping lock. Until the locking can be
+ * reworked this capability requires that the namespace
+ * is not claimed by btt.
+ */
+ if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+ && (!ndns->claim || !is_nd_btt(ndns->claim))) {
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev, offset, size);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-11 23:10 ` Dan Williams
0 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-11 23:10 UTC (permalink / raw)
To: linux-nvdimm; +Cc: Vishal Verma, Jeff Moyer, Dave Jiang, linux-kernel, stable
The following warning results from holding a lane spinlock,
preempt_disable(), or the btt map spinlock and then trying to take the
reconfig_mutex to walk the poison list and potentially add new entries.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747
in_atomic(): 1, irqs_disabled(): 0, pid: 17159, name: dd
[..]
Call Trace:
dump_stack+0x85/0xc8
___might_sleep+0x184/0x250
__might_sleep+0x4a/0x90
__mutex_lock+0x58/0x9b0
? nvdimm_bus_lock+0x21/0x30 [libnvdimm]
? __nvdimm_bus_badblocks_clear+0x2f/0x60 [libnvdimm]
? acpi_nfit_forget_poison+0x79/0x80 [nfit]
? _raw_spin_unlock+0x27/0x40
mutex_lock_nested+0x1b/0x20
nvdimm_bus_lock+0x21/0x30 [libnvdimm]
nvdimm_forget_poison+0x25/0x50 [libnvdimm]
nvdimm_clear_poison+0x106/0x140 [libnvdimm]
nsio_rw_bytes+0x164/0x270 [libnvdimm]
btt_write_pg+0x1de/0x3e0 [nd_btt]
? blk_queue_enter+0x30/0x290
btt_make_request+0x11a/0x310 [nd_btt]
? blk_queue_enter+0xb7/0x290
? blk_queue_enter+0x30/0x290
generic_make_request+0x118/0x3b0
As a minimal fix, disable error clearing when the BTT is enabled for the
namespace. For the final fix a larger rework of the poison list locking
is needed.
Note that this is not a problem in the blk case since that path never
calls nvdimm_clear_poison().
Cc: <stable@vger.kernel.org>
Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem")
Cc: Dave Jiang <dave.jiang@intel.com>
[jeff: dynamically disable error clearing in the btt case]
Suggested-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
v2: check for btt at run time rather than compile time (Jeff)
drivers/nvdimm/claim.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index b3323c0697f6..ca6d572c48fc 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -243,7 +243,15 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
- if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)) {
+ /*
+ * FIXME: nsio_rw_bytes() may be called from atomic
+ * context in the btt case and nvdimm_clear_poison()
+ * takes a sleeping lock. Until the locking can be
+ * reworked this capability requires that the namespace
+ * is not claimed by btt.
+ */
+ if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
+ && (!ndns->claim || !is_nd_btt(ndns->claim))) {
long cleared;
cleared = nvdimm_clear_poison(&ndns->dev, offset, size);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
2017-04-11 23:10 ` Dan Williams
(?)
@ 2017-04-12 12:49 ` Jeff Moyer
-1 siblings, 0 replies; 9+ messages in thread
From: Jeff Moyer @ 2017-04-12 12:49 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-kernel, stable, linux-nvdimm
Dan Williams <dan.j.williams@intel.com> writes:
> As a minimal fix, disable error clearing when the BTT is enabled for the
> namespace. For the final fix a larger rework of the poison list locking
> is needed.
I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-12 12:49 ` Jeff Moyer
0 siblings, 0 replies; 9+ messages in thread
From: Jeff Moyer @ 2017-04-12 12:49 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-nvdimm, Vishal Verma, Dave Jiang, linux-kernel, stable
Dan Williams <dan.j.williams@intel.com> writes:
> As a minimal fix, disable error clearing when the BTT is enabled for the
> namespace. For the final fix a larger rework of the poison list locking
> is needed.
I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-12 12:49 ` Jeff Moyer
0 siblings, 0 replies; 9+ messages in thread
From: Jeff Moyer @ 2017-04-12 12:49 UTC (permalink / raw)
To: Dan Williams; +Cc: linux-nvdimm, Vishal Verma, Dave Jiang, linux-kernel, stable
Dan Williams <dan.j.williams@intel.com> writes:
> As a minimal fix, disable error clearing when the BTT is enabled for the
> namespace. For the final fix a larger rework of the poison list locking
> is needed.
I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
2017-04-12 12:49 ` Jeff Moyer
(?)
@ 2017-04-12 20:49 ` Dan Williams
-1 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-12 20:49 UTC (permalink / raw)
To: Jeff Moyer; +Cc: linux-kernel, stable, linux-nvdimm
On Wed, Apr 12, 2017 at 5:49 AM, Jeff Moyer <jmoyer@redhat.com> wrote:
> Dan Williams <dan.j.williams@intel.com> writes:
>
>> As a minimal fix, disable error clearing when the BTT is enabled for the
>> namespace. For the final fix a larger rework of the poison list locking
>> is needed.
>
> I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Heh, true. I'll rename it to "band aid" since the true "fix" is coming in 4.12.
> Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Thanks!
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-12 20:49 ` Dan Williams
0 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-12 20:49 UTC (permalink / raw)
To: Jeff Moyer
Cc: linux-nvdimm@lists.01.org, Vishal Verma, Dave Jiang,
linux-kernel, stable
On Wed, Apr 12, 2017 at 5:49 AM, Jeff Moyer <jmoyer@redhat.com> wrote:
> Dan Williams <dan.j.williams@intel.com> writes:
>
>> As a minimal fix, disable error clearing when the BTT is enabled for the
>> namespace. For the final fix a larger rework of the poison list locking
>> is needed.
>
> I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Heh, true. I'll rename it to "band aid" since the true "fix" is coming in 4.12.
> Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Thanks!
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] libnvdimm: fix btt vs clear poison locking
@ 2017-04-12 20:49 ` Dan Williams
0 siblings, 0 replies; 9+ messages in thread
From: Dan Williams @ 2017-04-12 20:49 UTC (permalink / raw)
To: Jeff Moyer; +Cc: linux-nvdimm, Vishal Verma, Dave Jiang, linux-kernel, stable
On Wed, Apr 12, 2017 at 5:49 AM, Jeff Moyer <jmoyer@redhat.com> wrote:
> Dan Williams <dan.j.williams@intel.com> writes:
>
>> As a minimal fix, disable error clearing when the BTT is enabled for the
>> namespace. For the final fix a larger rework of the poison list locking
>> is needed.
>
> I think "fix" is a strong word for this patch. ;-) Looks fine, though.
Heh, true. I'll rename it to "band aid" since the true "fix" is coming in 4.12.
> Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Thanks!
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2017-04-12 20:49 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2017-04-11 23:10 [PATCH v2] libnvdimm: fix btt vs clear poison locking Dan Williams
2017-04-11 23:10 ` Dan Williams
2017-04-11 23:10 ` Dan Williams
2017-04-12 12:49 ` Jeff Moyer
2017-04-12 12:49 ` Jeff Moyer
2017-04-12 12:49 ` Jeff Moyer
2017-04-12 20:49 ` Dan Williams
2017-04-12 20:49 ` Dan Williams
2017-04-12 20:49 ` Dan Williams
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