<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/nvme/host, branch v5.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>nvme: add a Identify Namespace Identification Descriptor list quirk</title>
<updated>2020-07-29T06:05:44+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-07-28T11:09:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5bedd3afee8eb01ccd256f0cd2cc0fa6f841417a'/>
<id>5bedd3afee8eb01ccd256f0cd2cc0fa6f841417a</id>
<content type='text'>
Add a quirk for a device that does not support the Identify Namespace
Identification Descriptor list despite claiming 1.3 compliance.

Fixes: ea43d9709f72 ("nvme: fix identify error status silent ignore")
Reported-by: Ingo Brunberg &lt;ingo_brunberg@web.de&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Ingo Brunberg &lt;ingo_brunberg@web.de&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a quirk for a device that does not support the Identify Namespace
Identification Descriptor list despite claiming 1.3 compliance.

Fixes: ea43d9709f72 ("nvme: fix identify error status silent ignore")
Reported-by: Ingo Brunberg &lt;ingo_brunberg@web.de&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Ingo Brunberg &lt;ingo_brunberg@web.de&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme-pci: prevent SK hynix PC400 from using Write Zeroes command</title>
<updated>2020-07-26T15:28:19+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2020-07-23T17:29:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5611ec2b9814bc91f7b0a8d804c1fc152e2025d9'/>
<id>5611ec2b9814bc91f7b0a8d804c1fc152e2025d9</id>
<content type='text'>
After commit 6e02318eaea5 ("nvme: add support for the Write Zeroes
command"), SK hynix PC400 becomes very slow with the following error
message:

[  224.567695] blk_update_request: operation not supported error, dev nvme1n1, sector 499384320 op 0x9:(WRITE_ZEROES) flags 0x1000000 phys_seg 0 prio class 0]

SK Hynix PC400 has a buggy firmware that treats NLB as max value instead
of a range, so the NLB passed isn't a valid value to the firmware.

According to SK hynix there are three commands are affected:
- Write Zeroes
- Compare
- Write Uncorrectable

Right now only Write Zeroes is implemented, so disable it completely on
SK hynix PC400.

BugLink: https://bugs.launchpad.net/bugs/1872383
Cc: kyounghwan sohn &lt;kyounghwan.sohn@sk.com&gt;
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After commit 6e02318eaea5 ("nvme: add support for the Write Zeroes
command"), SK hynix PC400 becomes very slow with the following error
message:

[  224.567695] blk_update_request: operation not supported error, dev nvme1n1, sector 499384320 op 0x9:(WRITE_ZEROES) flags 0x1000000 phys_seg 0 prio class 0]

SK Hynix PC400 has a buggy firmware that treats NLB as max value instead
of a range, so the NLB passed isn't a valid value to the firmware.

According to SK hynix there are three commands are affected:
- Write Zeroes
- Compare
- Write Uncorrectable

Right now only Write Zeroes is implemented, so disable it completely on
SK hynix PC400.

BugLink: https://bugs.launchpad.net/bugs/1872383
Cc: kyounghwan sohn &lt;kyounghwan.sohn@sk.com&gt;
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme-tcp: fix possible hang waiting for icresp response</title>
<updated>2020-07-26T15:24:27+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2020-07-23T23:42:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=adc99fd378398f4c58798a1c57889872967d56a6'/>
<id>adc99fd378398f4c58798a1c57889872967d56a6</id>
<content type='text'>
If the controller died exactly when we are receiving icresp
we hang because icresp may never return. Make sure to set a
high finite limit.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the controller died exactly when we are receiving icresp
we hang because icresp may never return. Make sure to set a
high finite limit.

Fixes: 3f2304f8c6d6 ("nvme-tcp: add NVMe over TCP host driver")
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme: explicitly update mpath disk capacity on revalidation</title>
<updated>2020-07-16T14:40:27+00:00</updated>
<author>
<name>Anthony Iliopoulos</name>
<email>ailiop@suse.com</email>
</author>
<published>2020-07-14T11:11:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05b29021fba5e725dd385151ef00b6340229b500'/>
<id>05b29021fba5e725dd385151ef00b6340229b500</id>
<content type='text'>
Commit 3b4b19721ec652 ("nvme: fix possible deadlock when I/O is
blocked") reverted multipath head disk revalidation due to deadlocks
caused by holding the bd_mutex during revalidate.

Updating the multipath disk blockdev size is still required though for
userspace to be able to observe any resizing while the device is
mounted. Directly update the bdev inode size to avoid unnecessarily
holding the bdev-&gt;bd_mutex.

Fixes: 3b4b19721ec652 ("nvme: fix possible deadlock when I/O is
blocked")

Signed-off-by: Anthony Iliopoulos &lt;ailiop@suse.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 3b4b19721ec652 ("nvme: fix possible deadlock when I/O is
blocked") reverted multipath head disk revalidation due to deadlocks
caused by holding the bd_mutex during revalidate.

Updating the multipath disk blockdev size is still required though for
userspace to be able to observe any resizing while the device is
mounted. Directly update the bdev inode size to avoid unnecessarily
holding the bdev-&gt;bd_mutex.

Fixes: 3b4b19721ec652 ("nvme: fix possible deadlock when I/O is
blocked")

Signed-off-by: Anthony Iliopoulos &lt;ailiop@suse.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme: fix a crash in nvme_mpath_add_disk</title>
<updated>2020-07-02T08:38:00+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-06-29T14:30:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72d447113bb751ded97b2e2c38f886e4a4139082'/>
<id>72d447113bb751ded97b2e2c38f886e4a4139082</id>
<content type='text'>
For private namespaces ns-&gt;head_disk is NULL, so add a NULL check
before updating the BDI capabilities.

Fixes: b2ce4d90690b ("nvme-multipath: set bdi capabilities once")
Reported-by: Avinash M N &lt;Avinash.M.N@wdc.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Max Gurtovoy &lt;maxg@mellanox.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For private namespaces ns-&gt;head_disk is NULL, so add a NULL check
before updating the BDI capabilities.

Fixes: b2ce4d90690b ("nvme-multipath: set bdi capabilities once")
Reported-by: Avinash M N &lt;Avinash.M.N@wdc.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Max Gurtovoy &lt;maxg@mellanox.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme: fix identify error status silent ignore</title>
<updated>2020-07-02T08:38:00+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2020-06-26T17:46:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ea43d9709f727e728e933a8157a7a7ca1a868281'/>
<id>ea43d9709f727e728e933a8157a7a7ca1a868281</id>
<content type='text'>
Commit 59c7c3caaaf8 intended to only silently ignore non retry-able
errors (DNR bit set) such that we can still identify misbehaving
controllers, and in the other hand propagate retry-able errors (DNR bit
cleared) so we don't wrongly abandon a namespace just because it happens
to be temporarily inaccessible.

The goal remains the same as the original commit where this was
introduced but unfortunately had the logic backwards.

Fixes: 59c7c3caaaf8 ("nvme: fix possible hang when ns scanning fails during error recovery")
Reported-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 59c7c3caaaf8 intended to only silently ignore non retry-able
errors (DNR bit set) such that we can still identify misbehaving
controllers, and in the other hand propagate retry-able errors (DNR bit
cleared) so we don't wrongly abandon a namespace just because it happens
to be temporarily inaccessible.

The goal remains the same as the original commit where this was
introduced but unfortunately had the logic backwards.

Fixes: 59c7c3caaaf8 ("nvme: fix possible hang when ns scanning fails during error recovery")
Reported-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme-multipath: fix bogus request queue reference put</title>
<updated>2020-06-24T16:41:20+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2020-06-24T08:53:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c31244669f57963b6ce133a5555b118fc50aec95'/>
<id>c31244669f57963b6ce133a5555b118fc50aec95</id>
<content type='text'>
The mpath disk node takes a reference on the request mpath
request queue when adding live path to the mpath gendisk.
However if we connected to an inaccessible path device_add_disk
is not called, so if we disconnect and remove the mpath gendisk
we endup putting an reference on the request queue that was
never taken [1].

Fix that to check if we ever added a live path (using
NVME_NS_HEAD_HAS_DISK flag) and if not, clear the disk-&gt;queue
reference.

[1]:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 1372 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0
CPU: 1 PID: 1372 Comm: nvme Tainted: G           O      5.7.0-rc2+ #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xa6/0xf0
RSP: 0018:ffffb29e8053bdc0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8b7a2f4fc060 RCX: 0000000000000007
RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8b7a3ec99980
RBP: ffff8b7a2f4fc000 R08: 00000000000002e1 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: fffffffffffffff2 R14: ffffb29e8053bf08 R15: ffff8b7a320e2da0
FS:  00007f135d4ca800(0000) GS:ffff8b7a3ec80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005651178c0c30 CR3: 000000003b650005 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 disk_release+0xa2/0xc0
 device_release+0x28/0x80
 kobject_put+0xa5/0x1b0
 nvme_put_ns_head+0x26/0x70 [nvme_core]
 nvme_put_ns+0x30/0x60 [nvme_core]
 nvme_remove_namespaces+0x9b/0xe0 [nvme_core]
 nvme_do_delete_ctrl+0x43/0x5c [nvme_core]
 nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
 kernfs_fop_write+0xc1/0x1a0
 vfs_write+0xb6/0x1a0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x52/0x1a0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Tested-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The mpath disk node takes a reference on the request mpath
request queue when adding live path to the mpath gendisk.
However if we connected to an inaccessible path device_add_disk
is not called, so if we disconnect and remove the mpath gendisk
we endup putting an reference on the request queue that was
never taken [1].

Fix that to check if we ever added a live path (using
NVME_NS_HEAD_HAS_DISK flag) and if not, clear the disk-&gt;queue
reference.

[1]:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 1372 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0
CPU: 1 PID: 1372 Comm: nvme Tainted: G           O      5.7.0-rc2+ #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xa6/0xf0
RSP: 0018:ffffb29e8053bdc0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8b7a2f4fc060 RCX: 0000000000000007
RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8b7a3ec99980
RBP: ffff8b7a2f4fc000 R08: 00000000000002e1 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: fffffffffffffff2 R14: ffffb29e8053bf08 R15: ffff8b7a320e2da0
FS:  00007f135d4ca800(0000) GS:ffff8b7a3ec80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005651178c0c30 CR3: 000000003b650005 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 disk_release+0xa2/0xc0
 device_release+0x28/0x80
 kobject_put+0xa5/0x1b0
 nvme_put_ns_head+0x26/0x70 [nvme_core]
 nvme_put_ns+0x30/0x60 [nvme_core]
 nvme_remove_namespaces+0x9b/0xe0 [nvme_core]
 nvme_do_delete_ctrl+0x43/0x5c [nvme_core]
 nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
 kernfs_fop_write+0xc1/0x1a0
 vfs_write+0xb6/0x1a0
 ksys_write+0x5f/0xe0
 do_syscall_64+0x52/0x1a0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Tested-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme-multipath: fix deadlock due to head-&gt;lock</title>
<updated>2020-06-24T16:41:20+00:00</updated>
<author>
<name>Anton Eidelman</name>
<email>anton@lightbitslabs.com</email>
</author>
<published>2020-06-24T08:53:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8a22f85609fadb46ba699e0136cc3ebdeebff79'/>
<id>d8a22f85609fadb46ba699e0136cc3ebdeebff79</id>
<content type='text'>
In the following scenario scan_work and ana_work will deadlock:

When scan_work calls nvme_mpath_add_disk() this holds ana_lock
and invokes nvme_parse_ana_log(), which may issue IO
in device_add_disk() and hang waiting for an accessible path.

While nvme_mpath_set_live() only called when nvme_state_is_live(),
a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO.

Since nvme_mpath_set_live() holds ns-&gt;head-&gt;lock, an ana_work on
ANY ctrl will not be able to complete nvme_mpath_set_live()
on the same ns-&gt;head, which is required in order to update
the new accessible path and remove NVME_NS_ANA_PENDING..
Therefore IO never completes: deadlock [1].

Fix:
Move device_add_disk out of the head-&gt;lock and protect it with an
atomic test_and_set for a new NVME_NS_HEAD_HAS_DISK bit.

[1]:
kernel: INFO: task kworker/u8:2:160 blocked for more than 120 seconds.
kernel:       Tainted: G           OE     5.3.5-050305-generic #201910071830
kernel: "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: kworker/u8:2    D    0   160      2 0x80004000
kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  schedule_preempt_disabled+0xe/0x10
kernel:  __mutex_lock.isra.0+0x182/0x4f0
kernel:  __mutex_lock_slowpath+0x13/0x20
kernel:  mutex_lock+0x2e/0x40
kernel:  nvme_update_ns_ana_state+0x22/0x60 [nvme_core]
kernel:  nvme_update_ana_state+0xca/0xe0 [nvme_core]
kernel:  nvme_parse_ana_log+0xa1/0x180 [nvme_core]
kernel:  nvme_read_ana_log+0x76/0x100 [nvme_core]
kernel:  nvme_ana_work+0x15/0x20 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ret_from_fork+0x35/0x40
kernel: INFO: task kworker/u8:4:439 blocked for more than 120 seconds.
kernel:       Tainted: G           OE     5.3.5-050305-generic #201910071830
kernel: "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: kworker/u8:4    D    0   439      2 0x80004000
kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  io_schedule+0x16/0x40
kernel:  do_read_cache_page+0x438/0x830
kernel:  read_cache_page+0x12/0x20
kernel:  read_dev_sector+0x27/0xc0
kernel:  read_lba+0xc1/0x220
kernel:  efi_partition+0x1e6/0x708
kernel:  check_partition+0x154/0x244
kernel:  rescan_partitions+0xae/0x280
kernel:  __blkdev_get+0x40f/0x560
kernel:  blkdev_get+0x3d/0x140
kernel:  __device_add_disk+0x388/0x480
kernel:  device_add_disk+0x13/0x20
kernel:  nvme_mpath_set_live+0x119/0x140 [nvme_core]
kernel:  nvme_update_ns_ana_state+0x5c/0x60 [nvme_core]
kernel:  nvme_mpath_add_disk+0xbe/0x100 [nvme_core]
kernel:  nvme_validate_ns+0x396/0x940 [nvme_core]
kernel:  nvme_scan_work+0x256/0x390 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ret_from_fork+0x35/0x40

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the following scenario scan_work and ana_work will deadlock:

When scan_work calls nvme_mpath_add_disk() this holds ana_lock
and invokes nvme_parse_ana_log(), which may issue IO
in device_add_disk() and hang waiting for an accessible path.

While nvme_mpath_set_live() only called when nvme_state_is_live(),
a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO.

Since nvme_mpath_set_live() holds ns-&gt;head-&gt;lock, an ana_work on
ANY ctrl will not be able to complete nvme_mpath_set_live()
on the same ns-&gt;head, which is required in order to update
the new accessible path and remove NVME_NS_ANA_PENDING..
Therefore IO never completes: deadlock [1].

Fix:
Move device_add_disk out of the head-&gt;lock and protect it with an
atomic test_and_set for a new NVME_NS_HEAD_HAS_DISK bit.

[1]:
kernel: INFO: task kworker/u8:2:160 blocked for more than 120 seconds.
kernel:       Tainted: G           OE     5.3.5-050305-generic #201910071830
kernel: "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: kworker/u8:2    D    0   160      2 0x80004000
kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  schedule_preempt_disabled+0xe/0x10
kernel:  __mutex_lock.isra.0+0x182/0x4f0
kernel:  __mutex_lock_slowpath+0x13/0x20
kernel:  mutex_lock+0x2e/0x40
kernel:  nvme_update_ns_ana_state+0x22/0x60 [nvme_core]
kernel:  nvme_update_ana_state+0xca/0xe0 [nvme_core]
kernel:  nvme_parse_ana_log+0xa1/0x180 [nvme_core]
kernel:  nvme_read_ana_log+0x76/0x100 [nvme_core]
kernel:  nvme_ana_work+0x15/0x20 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ret_from_fork+0x35/0x40
kernel: INFO: task kworker/u8:4:439 blocked for more than 120 seconds.
kernel:       Tainted: G           OE     5.3.5-050305-generic #201910071830
kernel: "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kernel: kworker/u8:4    D    0   439      2 0x80004000
kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  io_schedule+0x16/0x40
kernel:  do_read_cache_page+0x438/0x830
kernel:  read_cache_page+0x12/0x20
kernel:  read_dev_sector+0x27/0xc0
kernel:  read_lba+0xc1/0x220
kernel:  efi_partition+0x1e6/0x708
kernel:  check_partition+0x154/0x244
kernel:  rescan_partitions+0xae/0x280
kernel:  __blkdev_get+0x40f/0x560
kernel:  blkdev_get+0x3d/0x140
kernel:  __device_add_disk+0x388/0x480
kernel:  device_add_disk+0x13/0x20
kernel:  nvme_mpath_set_live+0x119/0x140 [nvme_core]
kernel:  nvme_update_ns_ana_state+0x5c/0x60 [nvme_core]
kernel:  nvme_mpath_add_disk+0xbe/0x100 [nvme_core]
kernel:  nvme_validate_ns+0x396/0x940 [nvme_core]
kernel:  nvme_scan_work+0x256/0x390 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ret_from_fork+0x35/0x40

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme: don't protect ns mutation with ns-&gt;head-&gt;lock</title>
<updated>2020-06-24T16:41:20+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2020-06-24T08:53:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e164471dcf19308d154adb69e7760d8ba426a77f'/>
<id>e164471dcf19308d154adb69e7760d8ba426a77f</id>
<content type='text'>
Right now ns-&gt;head-&gt;lock is protecting namespace mutation
which is wrong and unneeded. Move it to only protect
against head mutations. While we're at it, remove unnecessary
ns-&gt;head reference as we already have head pointer.

The problem with this is that the head-&gt;lock spans
mpath disk node I/O that may block under some conditions (if
for example the controller is disconnecting or the path
became inaccessible), The locking scheme does not allow any
other path to enable itself, preventing blocked I/O to complete
and forward-progress from there.

This is a preparation patch for the fix in a subsequent patch
where the disk I/O will also be done outside the head-&gt;lock.

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Right now ns-&gt;head-&gt;lock is protecting namespace mutation
which is wrong and unneeded. Move it to only protect
against head mutations. While we're at it, remove unnecessary
ns-&gt;head reference as we already have head pointer.

The problem with this is that the head-&gt;lock spans
mpath disk node I/O that may block under some conditions (if
for example the controller is disconnecting or the path
became inaccessible), The locking scheme does not allow any
other path to enable itself, preventing blocked I/O to complete
and forward-progress from there.

This is a preparation patch for the fix in a subsequent patch
where the disk I/O will also be done outside the head-&gt;lock.

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nvme-multipath: fix deadlock between ana_work and scan_work</title>
<updated>2020-06-24T16:41:20+00:00</updated>
<author>
<name>Anton Eidelman</name>
<email>anton@lightbitslabs.com</email>
</author>
<published>2020-06-24T08:53:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=489dd102a2c7c94d783a35f9412eb085b8da1aa4'/>
<id>489dd102a2c7c94d783a35f9412eb085b8da1aa4</id>
<content type='text'>
When scan_work calls nvme_mpath_add_disk() this holds ana_lock
and invokes nvme_parse_ana_log(), which may issue IO
in device_add_disk() and hang waiting for an accessible path.
While nvme_mpath_set_live() only called when nvme_state_is_live(),
a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO.

In order to recover and complete the IO ana_work on the same ctrl
should be able to update the path state and remove NVME_NS_ANA_PENDING.

The deadlock occurs because scan_work keeps holding ana_lock,
so ana_work hangs [1].

Fix:
Now nvme_mpath_add_disk() uses nvme_parse_ana_log() to obtain a copy
of the ANA group desc, and then calls nvme_update_ns_ana_state() without
holding ana_lock.

[1]:
kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  io_schedule+0x16/0x40
kernel:  do_read_cache_page+0x438/0x830
kernel:  read_cache_page+0x12/0x20
kernel:  read_dev_sector+0x27/0xc0
kernel:  read_lba+0xc1/0x220
kernel:  efi_partition+0x1e6/0x708
kernel:  check_partition+0x154/0x244
kernel:  rescan_partitions+0xae/0x280
kernel:  __blkdev_get+0x40f/0x560
kernel:  blkdev_get+0x3d/0x140
kernel:  __device_add_disk+0x388/0x480
kernel:  device_add_disk+0x13/0x20
kernel:  nvme_mpath_set_live+0x119/0x140 [nvme_core]
kernel:  nvme_update_ns_ana_state+0x5c/0x60 [nvme_core]
kernel:  nvme_set_ns_ana_state+0x1e/0x30 [nvme_core]
kernel:  nvme_parse_ana_log+0xa1/0x180 [nvme_core]
kernel:  nvme_mpath_add_disk+0x47/0x90 [nvme_core]
kernel:  nvme_validate_ns+0x396/0x940 [nvme_core]
kernel:  nvme_scan_work+0x24f/0x380 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x249/0x400
kernel:  kthread+0x104/0x140

kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  schedule_preempt_disabled+0xe/0x10
kernel:  __mutex_lock.isra.0+0x182/0x4f0
kernel:  ? __switch_to_asm+0x34/0x70
kernel:  ? select_task_rq_fair+0x1aa/0x5c0
kernel:  ? kvm_sched_clock_read+0x11/0x20
kernel:  ? sched_clock+0x9/0x10
kernel:  __mutex_lock_slowpath+0x13/0x20
kernel:  mutex_lock+0x2e/0x40
kernel:  nvme_read_ana_log+0x3a/0x100 [nvme_core]
kernel:  nvme_ana_work+0x15/0x20 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ? process_one_work+0x380/0x380
kernel:  ? kthread_park+0x80/0x80
kernel:  ret_from_fork+0x35/0x40

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When scan_work calls nvme_mpath_add_disk() this holds ana_lock
and invokes nvme_parse_ana_log(), which may issue IO
in device_add_disk() and hang waiting for an accessible path.
While nvme_mpath_set_live() only called when nvme_state_is_live(),
a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO.

In order to recover and complete the IO ana_work on the same ctrl
should be able to update the path state and remove NVME_NS_ANA_PENDING.

The deadlock occurs because scan_work keeps holding ana_lock,
so ana_work hangs [1].

Fix:
Now nvme_mpath_add_disk() uses nvme_parse_ana_log() to obtain a copy
of the ANA group desc, and then calls nvme_update_ns_ana_state() without
holding ana_lock.

[1]:
kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  io_schedule+0x16/0x40
kernel:  do_read_cache_page+0x438/0x830
kernel:  read_cache_page+0x12/0x20
kernel:  read_dev_sector+0x27/0xc0
kernel:  read_lba+0xc1/0x220
kernel:  efi_partition+0x1e6/0x708
kernel:  check_partition+0x154/0x244
kernel:  rescan_partitions+0xae/0x280
kernel:  __blkdev_get+0x40f/0x560
kernel:  blkdev_get+0x3d/0x140
kernel:  __device_add_disk+0x388/0x480
kernel:  device_add_disk+0x13/0x20
kernel:  nvme_mpath_set_live+0x119/0x140 [nvme_core]
kernel:  nvme_update_ns_ana_state+0x5c/0x60 [nvme_core]
kernel:  nvme_set_ns_ana_state+0x1e/0x30 [nvme_core]
kernel:  nvme_parse_ana_log+0xa1/0x180 [nvme_core]
kernel:  nvme_mpath_add_disk+0x47/0x90 [nvme_core]
kernel:  nvme_validate_ns+0x396/0x940 [nvme_core]
kernel:  nvme_scan_work+0x24f/0x380 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x249/0x400
kernel:  kthread+0x104/0x140

kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core]
kernel: Call Trace:
kernel:  __schedule+0x2b9/0x6c0
kernel:  schedule+0x42/0xb0
kernel:  schedule_preempt_disabled+0xe/0x10
kernel:  __mutex_lock.isra.0+0x182/0x4f0
kernel:  ? __switch_to_asm+0x34/0x70
kernel:  ? select_task_rq_fair+0x1aa/0x5c0
kernel:  ? kvm_sched_clock_read+0x11/0x20
kernel:  ? sched_clock+0x9/0x10
kernel:  __mutex_lock_slowpath+0x13/0x20
kernel:  mutex_lock+0x2e/0x40
kernel:  nvme_read_ana_log+0x3a/0x100 [nvme_core]
kernel:  nvme_ana_work+0x15/0x20 [nvme_core]
kernel:  process_one_work+0x1db/0x380
kernel:  worker_thread+0x4d/0x400
kernel:  kthread+0x104/0x140
kernel:  ? process_one_work+0x380/0x380
kernel:  ? kthread_park+0x80/0x80
kernel:  ret_from_fork+0x35/0x40

Fixes: 0d0b660f214d ("nvme: add ANA support")
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
