[PATCH V2 0/2] *** Test the NVMe reservation feature ***

[PATCH V2 0/2] *** Test the NVMe reservation feature ***

[Guixin Liu]

Changes from v1 to v2:
- Add a new patch to add a optinal argument --resv_enable.

- Make resv-report fit the new --eds argument.

- Filter the hosid output to make the new test case independent from
hostid.

- Change the new test case name to "Test the NVMe reservation feature".

Guixin Liu (2):
  nvme/{rc,002,016,017,030,031}: introduce --resv_enable argument
  test/nvme/050: test the reservation feature

 tests/nvme/002     |   3 +-
 tests/nvme/016     |   7 ++-
 tests/nvme/017     |  10 +++--
 tests/nvme/030     |   6 ++-
 tests/nvme/031     |   3 +-
 tests/nvme/050     |  96 ++++++++++++++++++++++++++++++++++++++++
 tests/nvme/050.out | 108 +++++++++++++++++++++++++++++++++++++++++++++
 tests/nvme/rc      | 100 ++++++++++++++++++++++++++++++++++-------
 8 files changed, 308 insertions(+), 25 deletions(-)
 create mode 100644 tests/nvme/050
 create mode 100644 tests/nvme/050.out

-- 
2.30.1 (Apple Git-130)

[PATCH V2 1/2] nvme/{rc,002,016,017,030,031}: introduce --resv_enable argument

[Guixin Liu]

Add an optional argument --resv_enable to _nvmet_target_setup() and
propagate it to _create_nvmet_subsystem() and _create_nvmet_ns().

One can call functions with --resv_enable to enable reservation
feature on a specific namespace.

Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
---
 tests/nvme/002 |   3 +-
 tests/nvme/016 |   7 +++-
 tests/nvme/017 |  10 +++--
 tests/nvme/030 |   6 ++-
 tests/nvme/031 |   3 +-
 tests/nvme/rc  | 100 +++++++++++++++++++++++++++++++++++++++++--------
 6 files changed, 104 insertions(+), 25 deletions(-)

diff --git a/tests/nvme/002 b/tests/nvme/002
index 6b84848..37c719b 100755
--- a/tests/nvme/002
+++ b/tests/nvme/002
@@ -30,7 +30,8 @@ test() {
 	local genctr=1
 
 	for ((i = 0; i < iterations; i++)); do
-		_create_nvmet_subsystem "blktests-subsystem-$i" "${loop_dev}"
+		_create_nvmet_subsystem --subsysnqn "blktests-subsystem-$i" \
+					--blkdev "${loop_dev}"
 		_add_nvmet_subsys_to_port "${port}" "blktests-subsystem-$i"
 	done
 
diff --git a/tests/nvme/016 b/tests/nvme/016
index 908abbd..ba700d1 100755
--- a/tests/nvme/016
+++ b/tests/nvme/016
@@ -25,10 +25,13 @@ test() {
 	loop_dev="$(losetup -f)"
 	local genctr=1
 
-	_create_nvmet_subsystem "${def_subsysnqn}" "${loop_dev}"
+	_create_nvmet_subsystem --subsysnqn "${def_subsysnqn}" \
+				--blkdev "${loop_dev}"
 
 	for ((i = 2; i <= iterations; i++)); do
-		_create_nvmet_ns "${def_subsysnqn}" "${i}" "${loop_dev}"
+		_create_nvmet_ns --subsysnqn "${def_subsysnqn}" \
+				 --nsid "${i}" \
+				 --blkdev "${loop_dev}"
 	done
 
 	port="$(_create_nvmet_port "${nvme_trtype}")"
diff --git a/tests/nvme/017 b/tests/nvme/017
index c8d9b32..d9fbd38 100755
--- a/tests/nvme/017
+++ b/tests/nvme/017
@@ -25,12 +25,14 @@ test() {
 
 	local genctr=1
 
-	_create_nvmet_subsystem "${def_subsysnqn}" "$(_nvme_def_file_path)" \
-		"${def_subsys_uuid}"
+	_create_nvmet_subsystem --subsysnqn "${def_subsysnqn}" \
+				--blkdev "$(_nvme_def_file_path)" \
+				--uuid "${def_subsys_uuid}"
 
 	for ((i = 2; i <= iterations; i++)); do
-		_create_nvmet_ns "${def_subsysnqn}" "${i}" \
-				 "$(_nvme_def_file_path)"
+		_create_nvmet_ns --subsysnqn "${def_subsysnqn}" \
+				 --nsid "${i}" \
+				 --blkdev "$(_nvme_def_file_path)"
 	done
 
 	port="$(_create_nvmet_port "${nvme_trtype}")"
diff --git a/tests/nvme/030 b/tests/nvme/030
index 9251e17..8802b16 100755
--- a/tests/nvme/030
+++ b/tests/nvme/030
@@ -26,13 +26,15 @@ test() {
 
 	port="$(_create_nvmet_port "${nvme_trtype}")"
 
-	_create_nvmet_subsystem "${subsys}1" "$(losetup -f)"
+	_create_nvmet_subsystem --subsysnqn "${subsys}1" \
+				--blkdev "$(losetup -f)"
 	_add_nvmet_subsys_to_port "${port}" "${subsys}1"
 	_create_nvmet_host "${subsys}1" "${def_hostnqn}"
 
 	genctr=$(_discovery_genctr)
 
-	_create_nvmet_subsystem "${subsys}2" "$(losetup -f)"
+	_create_nvmet_subsystem --subsysnqn "${subsys}2" \
+				--blkdev "$(losetup -f)"
 	_add_nvmet_subsys_to_port "${port}" "${subsys}2"
 
 	genctr=$(_check_genctr "${genctr}" "adding a subsystem to a port")
diff --git a/tests/nvme/031 b/tests/nvme/031
index ed5f196..191ce72 100755
--- a/tests/nvme/031
+++ b/tests/nvme/031
@@ -40,7 +40,8 @@ test() {
 	port="$(_create_nvmet_port "${nvme_trtype}")"
 
 	for ((i = 0; i < iterations; i++)); do
-		_create_nvmet_subsystem "${subsys}$i" "${loop_dev}"
+		_create_nvmet_subsystem --subsysnqn "${subsys}$i" \
+					--blkdev "${loop_dev}"
 		_add_nvmet_subsys_to_port "${port}" "${subsys}$i"
 		_create_nvmet_host "${subsys}$i" "${def_hostnqn}"
 		_nvme_connect_subsys "${nvme_trtype}" "${subsys}$i"
diff --git a/tests/nvme/rc b/tests/nvme/rc
index b0ef1ee..c6466cc 100644
--- a/tests/nvme/rc
+++ b/tests/nvme/rc
@@ -656,32 +656,95 @@ _remove_nvmet_port() {
 }
 
 _create_nvmet_ns() {
-	local nvmet_subsystem="$1"
-	local nsid="$2"
-	local blkdev="$3"
+	local nvmet_subsystem=""
+	local nsid=""
+	local blkdev=""
 	local uuid="00000000-0000-0000-0000-000000000000"
-	local subsys_path="${NVMET_CFS}/subsystems/${nvmet_subsystem}"
-	local ns_path="${subsys_path}/namespaces/${nsid}"
+	local subsys_path=""
+	local ns_path=""
+	local resv_enable=false
 
-	if [[ $# -eq 4 ]]; then
-		uuid="$4"
-	fi
+	while [[ $# -gt 0 ]]; do
+		case $1 in
+			--subsysnqn)
+				nvmet_subsystem="$2"
+				shift 2
+				;;
+			--nsid)
+				nsid="$2"
+				shift 2
+				;;
+			--blkdev)
+				blkdev="$2"
+				shift 2
+				;;
+			--uuid)
+				uuid="$2"
+				shift 2
+				;;
+			--resv_enable)
+				resv_enable=true
+				shift 1
+				;;
+			*)
+				echo "WARNING: unknown argument: $1"
+				shift
+				;;
+		esac
+	done
+
+	subsys_path="${NVMET_CFS}/subsystems/${nvmet_subsystem}"
+	ns_path="${subsys_path}/namespaces/${nsid}"
 
 	mkdir "${ns_path}"
 	printf "%s" "${blkdev}" > "${ns_path}/device_path"
 	printf "%s" "${uuid}" > "${ns_path}/device_uuid"
+	if [[ -f "${ns_path}/resv_enable" && "${resv_enable}" = true ]] ; then
+		printf 1 > "${ns_path}/resv_enable"
+	fi
 	printf 1 > "${ns_path}/enable"
 }
 
 _create_nvmet_subsystem() {
-	local nvmet_subsystem="$1"
-	local blkdev="$2"
-	local uuid=$3
-	local cfs_path="${NVMET_CFS}/subsystems/${nvmet_subsystem}"
+	local nvmet_subsystem=""
+	local blkdev=""
+	local uuid="00000000-0000-0000-0000-000000000000"
+	local resv_enable=""
+	local cfs_path=""
 
+	while [[ $# -gt 0 ]]; do
+		case $1 in
+			--subsysnqn)
+				nvmet_subsystem="$2"
+				shift 2
+				;;
+			--blkdev)
+				blkdev="$2"
+				shift 2
+				;;
+			--uuid)
+				uuid="$2"
+				shift 2
+				;;
+			--resv_enable)
+				resv_enable="--resv_enable";
+				shift 1
+				;;
+			*)
+				echo "WARNING: unknown argument: $1"
+				shift
+				;;
+		esac
+	done
+
+	cfs_path="${NVMET_CFS}/subsystems/${nvmet_subsystem}"
 	mkdir -p "${cfs_path}"
 	echo 0 > "${cfs_path}/attr_allow_any_host"
-	_create_nvmet_ns "${nvmet_subsystem}" "1" "${blkdev}" "${uuid}"
+	_create_nvmet_ns --subsysnqn "${nvmet_subsystem}" \
+			 --nsid "1" \
+			 --blkdev "${blkdev}" \
+			 --uuid "${uuid}" \
+			 ${resv_enable}
 }
 
 _add_nvmet_allow_hosts() {
@@ -863,6 +926,7 @@ _nvmet_target_setup() {
 	local ctrlkey=""
 	local hostkey=""
 	local port
+	local resv_enable=""
 
 	while [[ $# -gt 0 ]]; do
 		case $1 in
@@ -878,6 +942,10 @@ _nvmet_target_setup() {
 				hostkey="$2"
 				shift 2
 				;;
+			--resv_enable)
+				resv_enable="--resv_enable"
+				shift 1
+				;;
 			*)
 				echo "WARNING: unknown argument: $1"
 				shift
@@ -892,8 +960,10 @@ _nvmet_target_setup() {
 		blkdev="$(_nvme_def_file_path)"
 	fi
 
-	_create_nvmet_subsystem "${def_subsysnqn}" "${blkdev}" \
-				"${def_subsys_uuid}"
+	_create_nvmet_subsystem --subsysnqn "${def_subsysnqn}" \
+				--blkdev "${blkdev}" \
+				--uuid "${def_subsys_uuid}" \
+				${resv_enable}
 	port="$(_create_nvmet_port "${nvme_trtype}")"
 	_add_nvmet_subsys_to_port "${port}" "${def_subsysnqn}"
 	_create_nvmet_host "${def_subsysnqn}" "${def_hostnqn}" \
-- 
2.30.1 (Apple Git-130)

Re: [PATCH V2 1/2] nvme/{rc,002,016,017,030,031}: introduce --resv_enable argument

[Shinichiro Kawasaki]

On Jan 17, 2024 / 16:17, Guixin Liu wrote:
> Add an optional argument --resv_enable to _nvmet_target_setup() and
> propagate it to _create_nvmet_subsystem() and _create_nvmet_ns().
> 
> One can call functions with --resv_enable to enable reservation
> feature on a specific namespace.
> 
> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>

Thanks, looks good to me.

Daniel, could you take a look in this patch? I think it is consistent with your
work on _nvme_connect_subsys() and _nvmet_target_setup() in the past.

Re: Re: [PATCH V2 1/2] nvme/{rc,002,016,017,030,031}: introduce --resv_enable argument

[Daniel Wagner]

On Tue, Jan 23, 2024 at 10:54:07AM +0000, Shinichiro Kawasaki wrote:
> On Jan 17, 2024 / 16:17, Guixin Liu wrote:
> > Add an optional argument --resv_enable to _nvmet_target_setup() and
> > propagate it to _create_nvmet_subsystem() and _create_nvmet_ns().
> > 
> > One can call functions with --resv_enable to enable reservation
> > feature on a specific namespace.
> > 
> > Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
> 
> Thanks, looks good to me.
> 
> Daniel, could you take a look in this patch? I think it is consistent with your
> work on _nvme_connect_subsys() and _nvmet_target_setup() in the past.

It teaches _create_nvmet_ns and _create_nvmet_subsystem to parse for
arguments as we have for the function you named. This makes these
function a bit more flexible to use. Looks good to me. Thanks!

Reviewed-by: Daniel Wagner <dwagner@suse.de>

[PATCH V2 2/2] test/nvme/050: test the reservation feature

[Guixin Liu]

Test the reservation feature, includes register, acquire, release
and report.

Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
---
 tests/nvme/050     |  96 ++++++++++++++++++++++++++++++++++++++++
 tests/nvme/050.out | 108 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+)
 create mode 100644 tests/nvme/050
 create mode 100644 tests/nvme/050.out

diff --git a/tests/nvme/050 b/tests/nvme/050
new file mode 100644
index 0000000..7e59de4
--- /dev/null
+++ b/tests/nvme/050
@@ -0,0 +1,96 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2024 Guixin Liu
+# Copyright (C) 2024 Alibaba Group.
+#
+# Test the NVMe reservation feature
+#
+. tests/nvme/rc
+
+DESCRIPTION="test the reservation feature"
+QUICK=1
+
+requires() {
+	_nvme_requires
+}
+
+resv_report() {
+	local nvmedev=$1
+
+	if nvme resv-report --help 2>&1 | grep -- '--eds' > /dev/null; then
+		nvme resv-report "/dev/${nvmedev}n1" --eds | grep -v "hostid"
+	else
+		nvme resv-report "/dev/${nvmedev}n1" --cdw11=1 | grep -v "hostid"
+	fi
+}
+
+test_resv() {
+	local nvmedev=$1
+
+	echo "Register"
+	resv_report "${nvmedev}"
+	nvme resv-register "/dev/${nvmedev}n1" --nrkey=4 --rrega=0
+	resv_report "${nvmedev}"
+
+	echo "Replace"
+	nvme resv-register "/dev/${nvmedev}n1" --crkey=4 --nrkey=5 --rrega=2
+	resv_report "${nvmedev}"
+
+	echo "Unregister"
+	nvme resv-register "/dev/${nvmedev}n1" --crkey=5 --rrega=1
+	resv_report "${nvmedev}"
+
+	echo "Acquire"
+	nvme resv-register "/dev/${nvmedev}n1" --nrkey=4 --rrega=0
+	nvme resv-acquire "/dev/${nvmedev}n1" --crkey=4 --rtype=1 --racqa=0
+	resv_report "${nvmedev}"
+
+	echo "Preempt"
+	nvme resv-acquire "/dev/${nvmedev}n1" --crkey=4 --rtype=2 --racqa=1
+	resv_report "${nvmedev}"
+
+	echo "Release"
+	nvme resv-release "/dev/${nvmedev}n1" --crkey=4 --rtype=2 --rrela=0
+	resv_report "${nvmedev}"
+
+	echo "Clear"
+	nvme resv-register "/dev/${nvmedev}n1" --nrkey=4 --rrega=0
+	nvme resv-acquire "/dev/${nvmedev}n1" --crkey=4 --rtype=1 --racqa=0
+	resv_report "${nvmedev}"
+	nvme resv-release "/dev/${nvmedev}n1" --crkey=4 --rrela=1
+}
+
+test() {
+	echo "Running ${TEST_NAME}"
+
+	_setup_nvmet
+
+	local nvmedev
+	local skipped=false
+	local subsys_path=""
+	local ns_path=""
+
+	_nvmet_target_setup --blkdev file --resv_enable
+	subsys_path="${NVMET_CFS}/subsystems/${def_subsysnqn}"
+	ns_path="${subsys_path}/namespaces/1"
+
+	if [[ -f "${ns_path}/resv_enable" ]] ; then
+		_nvme_connect_subsys "${nvme_trtype}" "${def_subsysnqn}"
+
+		nvmedev=$(_find_nvme_dev "${def_subsysnqn}")
+
+		test_resv "${nvmedev}"
+		_nvme_disconnect_subsys "${def_subsysnqn}"
+	else
+		SKIP_REASONS+=("missing reservation feature")
+		skipped=true
+	fi
+
+	_nvmet_target_cleanup
+
+	if [[ "${skipped}" = true ]] ; then
+		return 1
+	fi
+
+	echo "Test complete"
+}
diff --git a/tests/nvme/050.out b/tests/nvme/050.out
new file mode 100644
index 0000000..2a46b32
--- /dev/null
+++ b/tests/nvme/050.out
@@ -0,0 +1,108 @@
+Running nvme/050
+Register
+
+NVME Reservation status:
+
+gen       : 0
+rtype     : 0
+regctl    : 0
+ptpls     : 0
+
+NVME Reservation  success
+
+NVME Reservation status:
+
+gen       : 1
+rtype     : 0
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 0
+  rkey       : 4
+
+Replace
+NVME Reservation  success
+
+NVME Reservation status:
+
+gen       : 2
+rtype     : 0
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 0
+  rkey       : 5
+
+Unregister
+NVME Reservation  success
+
+NVME Reservation status:
+
+gen       : 3
+rtype     : 0
+regctl    : 0
+ptpls     : 0
+
+Acquire
+NVME Reservation  success
+NVME Reservation Acquire success
+
+NVME Reservation status:
+
+gen       : 4
+rtype     : 1
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 1
+  rkey       : 4
+
+Preempt
+NVME Reservation Acquire success
+
+NVME Reservation status:
+
+gen       : 5
+rtype     : 2
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 1
+  rkey       : 4
+
+Release
+NVME Reservation Release success
+
+NVME Reservation status:
+
+gen       : 5
+rtype     : 0
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 0
+  rkey       : 4
+
+Clear
+NVME Reservation  success
+NVME Reservation Acquire success
+
+NVME Reservation status:
+
+gen       : 6
+rtype     : 1
+regctl    : 1
+ptpls     : 0
+regctlext[0] :
+  cntlid     : 1
+  rcsts      : 1
+  rkey       : 4
+
+NVME Reservation Release success
+disconnected 1 controller(s)
+Test complete
-- 
2.30.1 (Apple Git-130)

Re: [PATCH V2 2/2] test/nvme/050: test the reservation feature

[Shinichiro Kawasaki]

On Jan 17, 2024 / 16:17, Guixin Liu wrote:
> Test the reservation feature, includes register, acquire, release
> and report.
> 
> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>

Thanks for this v2. I ran it with kernel side v4 patch [1], enabling lockdep.
And I observed lockdep WARN [2]. For your reference, I attached the WARN at
the end of this e-mail.

[1] https://lore.kernel.org/linux-nvme/20240118125057.56200-2-kanie@linux.alibaba.com/

This blktests patch looks almost good for me. Please find minor nit comments
in line.

> ---
>  tests/nvme/050     |  96 ++++++++++++++++++++++++++++++++++++++++
>  tests/nvme/050.out | 108 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 204 insertions(+)
>  create mode 100644 tests/nvme/050
>  create mode 100644 tests/nvme/050.out
> 
> diff --git a/tests/nvme/050 b/tests/nvme/050
> new file mode 100644
> index 0000000..7e59de4
> --- /dev/null
> +++ b/tests/nvme/050
> @@ -0,0 +1,96 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2024 Guixin Liu
> +# Copyright (C) 2024 Alibaba Group.
> +#
> +# Test the NVMe reservation feature
> +#
> +. tests/nvme/rc
> +
> +DESCRIPTION="test the reservation feature"
> +QUICK=1
> +
> +requires() {
> +	_nvme_requires
> +}
> +
> +resv_report() {
> +	local nvmedev=$1
> +
> +	if nvme resv-report --help 2>&1 | grep -- '--eds' > /dev/null; then

It feels costly to call "resv-report --help" multiple times. I suggest to call
it only once at the beginning of test_resv(). Based on the check result, a local
variable can be set up and passed to resv_report().

> +		nvme resv-report "/dev/${nvmedev}n1" --eds | grep -v "hostid"
> +	else
> +		nvme resv-report "/dev/${nvmedev}n1" --cdw11=1 | grep -v "hostid"

The two lines above are almost same. I think they can be unified with the
variable passed from the caller.

> +	fi
> +}
> +

[...]

[2]

run blktests nvme/050 at 2024-01-23 19:05:08
nvmet: adding nsid 1 to subsystem blktests-subsystem-1
nvmet: creating nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
nvme nvme1: Please enable CONFIG_NVME_MULTIPATH for full support of multi-port devices.
nvme nvme1: creating 4 I/O queues.
nvme nvme1: new ctrl: "blktests-subsystem-1"
nvme nvme1: Removing ctrl: NQN "blktests-subsystem-1"

======================================================
WARNING: possible circular locking dependency detected
6.7.0+ #142 Not tainted
------------------------------------------------------
check/1061 is trying to acquire lock:
ffff888139743a78 (&ns->pr.pr_lock){+.+.}-{3:3}, at: nvmet_pr_exit_ns+0x2e/0x230 [nvmet]

but task is already holding lock:
ffff888110cf7070 (&subsys->lock#2){+.+.}-{3:3}, at: nvmet_ns_disable+0x2a2/0x4a0 [nvmet]

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&subsys->lock#2){+.+.}-{3:3}:
       __mutex_lock+0x185/0x18c0
       nvmet_pr_send_resv_released+0x57/0x220 [nvmet]
       nvmet_pr_preempt+0x651/0xc80 [nvmet]
       nvmet_execute_pr_acquire+0x26f/0x5c0 [nvmet]
       process_one_work+0x74c/0x1260
       worker_thread+0x723/0x1300
       kthread+0x2f1/0x3d0
       ret_from_fork+0x30/0x70
       ret_from_fork_asm+0x1b/0x30

-> #0 (&ns->pr.pr_lock){+.+.}-{3:3}:
       __lock_acquire+0x2e96/0x5f40
       lock_acquire+0x1a9/0x4e0
       __mutex_lock+0x185/0x18c0
       nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
       nvmet_ns_disable+0x313/0x4a0 [nvmet]
       nvmet_ns_enable_store+0x8a/0xe0 [nvmet]
       configfs_write_iter+0x2ae/0x460
       vfs_write+0x540/0xd90
       ksys_write+0xf7/0x1d0
       do_syscall_64+0x60/0xe0
       entry_SYSCALL_64_after_hwframe+0x6e/0x76

other info that might help us debug this:

Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&subsys->lock#2);
                               lock(&ns->pr.pr_lock);
                               lock(&subsys->lock#2);
  lock(&ns->pr.pr_lock);

 *** DEADLOCK ***

4 locks held by check/1061:
 #0: ffff88813a8e8418 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0xf7/0x1d0
 #1: ffff88811e893a88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x73/0x460
 #2: ffff88812e673978 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x1db/0x460
 #3: ffff888110cf7070 (&subsys->lock#2){+.+.}-{3:3}, at: nvmet_ns_disable+0x2a2/0x4a0 [nvmet]

stack backtrace:
CPU: 0 PID: 1061 Comm: check Not tainted 6.7.0+ #142
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x57/0x90
 check_noncircular+0x309/0x3f0
 ? __pfx_check_noncircular+0x10/0x10
 ? lockdep_lock+0xca/0x1c0
 ? __pfx_lockdep_lock+0x10/0x10
 ? lock_release+0x378/0x650
 ? __stack_depot_save+0x246/0x470
 __lock_acquire+0x2e96/0x5f40
 ? __pfx___lock_acquire+0x10/0x10
 lock_acquire+0x1a9/0x4e0
 ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
 ? __pfx_lock_acquire+0x10/0x10
 ? lock_is_held_type+0xce/0x120
 ? __pfx_lock_acquire+0x10/0x10
 ? __pfx___might_resched+0x10/0x10
 __mutex_lock+0x185/0x18c0
 ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
 ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
 ? rcu_is_watching+0x11/0xb0
 ? __mutex_lock+0x2a2/0x18c0
 ? __pfx___mutex_lock+0x10/0x10
 ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
 nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
 nvmet_ns_disable+0x313/0x4a0 [nvmet]
 ? __pfx_nvmet_ns_disable+0x10/0x10 [nvmet]
 nvmet_ns_enable_store+0x8a/0xe0 [nvmet]
 ? __pfx_nvmet_ns_enable_store+0x10/0x10 [nvmet]
 configfs_write_iter+0x2ae/0x460
 vfs_write+0x540/0xd90
 ? __pfx_vfs_write+0x10/0x10
 ? __pfx___lock_acquire+0x10/0x10
 ? __handle_mm_fault+0x12c5/0x1870
 ? __fget_light+0x51/0x220
 ksys_write+0xf7/0x1d0
 ? __pfx_ksys_write+0x10/0x10
 ? syscall_enter_from_user_mode+0x22/0x90
 do_syscall_64+0x60/0xe0
 ? __pfx_lock_release+0x10/0x10
 ? count_memcg_events.constprop.0+0x4a/0x60
 ? handle_mm_fault+0x1b1/0x9d0
 ? exc_page_fault+0xc0/0x100
 ? rcu_is_watching+0x11/0xb0
 ? asm_exc_page_fault+0x22/0x30
 ? lockdep_hardirqs_on+0x7d/0x100
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7f604525ac34
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 77 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007ffec7fd6ce8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f604525ac34
RDX: 0000000000000002 RSI: 0000562b0cd805a0 RDI: 0000000000000001
RBP: 00007ffec7fd6d10 R08: 0000000000001428 R09: 0000000100000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 0000562b0cd805a0 R14: 00007f604532b5c0 R15: 00007f6045328f20
 </TASK>

Re: [PATCH V2 2/2] test/nvme/050: test the reservation feature

[Guixin Liu]

在 2024/1/23 19:21, Shinichiro Kawasaki 写道:
> On Jan 17, 2024 / 16:17, Guixin Liu wrote:
>> Test the reservation feature, includes register, acquire, release
>> and report.
>>
>> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
> Thanks for this v2. I ran it with kernel side v4 patch [1], enabling lockdep.
> And I observed lockdep WARN [2]. For your reference, I attached the WARN at
> the end of this e-mail.
>
> [1] https://lore.kernel.org/linux-nvme/20240118125057.56200-2-kanie@linux.alibaba.com/
>
> This blktests patch looks almost good for me. Please find minor nit comments
> in line.
>
>> ---
>>   tests/nvme/050     |  96 ++++++++++++++++++++++++++++++++++++++++
>>   tests/nvme/050.out | 108 +++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 204 insertions(+)
>>   create mode 100644 tests/nvme/050
>>   create mode 100644 tests/nvme/050.out
>>
>> diff --git a/tests/nvme/050 b/tests/nvme/050
>> new file mode 100644
>> index 0000000..7e59de4
>> --- /dev/null
>> +++ b/tests/nvme/050
>> @@ -0,0 +1,96 @@
>> +#!/bin/bash
>> +# SPDX-License-Identifier: GPL-3.0+
>> +# Copyright (C) 2024 Guixin Liu
>> +# Copyright (C) 2024 Alibaba Group.
>> +#
>> +# Test the NVMe reservation feature
>> +#
>> +. tests/nvme/rc
>> +
>> +DESCRIPTION="test the reservation feature"
>> +QUICK=1
>> +
>> +requires() {
>> +	_nvme_requires
>> +}
>> +
>> +resv_report() {
>> +	local nvmedev=$1
>> +
>> +	if nvme resv-report --help 2>&1 | grep -- '--eds' > /dev/null; then
> It feels costly to call "resv-report --help" multiple times. I suggest to call
> it only once at the beginning of test_resv(). Based on the check result, a local
> variable can be set up and passed to resv_report().
OK, I will change it in v3.
>> +		nvme resv-report "/dev/${nvmedev}n1" --eds | grep -v "hostid"
>> +	else
>> +		nvme resv-report "/dev/${nvmedev}n1" --cdw11=1 | grep -v "hostid"
> The two lines above are almost same. I think they can be unified with the
> variable passed from the caller.
OK, I will change it in v3.
>
>> +	fi
>> +}
>> +
> [...]
>
> [2]
>
> run blktests nvme/050 at 2024-01-23 19:05:08
> nvmet: adding nsid 1 to subsystem blktests-subsystem-1
> nvmet: creating nvm controller 1 for subsystem blktests-subsystem-1 for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349.
> nvme nvme1: Please enable CONFIG_NVME_MULTIPATH for full support of multi-port devices.
> nvme nvme1: creating 4 I/O queues.
> nvme nvme1: new ctrl: "blktests-subsystem-1"
> nvme nvme1: Removing ctrl: NQN "blktests-subsystem-1"
>
> ======================================================
> WARNING: possible circular locking dependency detected
> 6.7.0+ #142 Not tainted
> ------------------------------------------------------
> check/1061 is trying to acquire lock:
> ffff888139743a78 (&ns->pr.pr_lock){+.+.}-{3:3}, at: nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>
> but task is already holding lock:
> ffff888110cf7070 (&subsys->lock#2){+.+.}-{3:3}, at: nvmet_ns_disable+0x2a2/0x4a0 [nvmet]
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #1 (&subsys->lock#2){+.+.}-{3:3}:
>         __mutex_lock+0x185/0x18c0
>         nvmet_pr_send_resv_released+0x57/0x220 [nvmet]
>         nvmet_pr_preempt+0x651/0xc80 [nvmet]
>         nvmet_execute_pr_acquire+0x26f/0x5c0 [nvmet]
>         process_one_work+0x74c/0x1260
>         worker_thread+0x723/0x1300
>         kthread+0x2f1/0x3d0
>         ret_from_fork+0x30/0x70
>         ret_from_fork_asm+0x1b/0x30
>
> -> #0 (&ns->pr.pr_lock){+.+.}-{3:3}:
>         __lock_acquire+0x2e96/0x5f40
>         lock_acquire+0x1a9/0x4e0
>         __mutex_lock+0x185/0x18c0
>         nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>         nvmet_ns_disable+0x313/0x4a0 [nvmet]
>         nvmet_ns_enable_store+0x8a/0xe0 [nvmet]
>         configfs_write_iter+0x2ae/0x460
>         vfs_write+0x540/0xd90
>         ksys_write+0xf7/0x1d0
>         do_syscall_64+0x60/0xe0
>         entry_SYSCALL_64_after_hwframe+0x6e/0x76
>
> other info that might help us debug this:
>
> Possible unsafe locking scenario:
>
>         CPU0                    CPU1
>         ----                    ----
>    lock(&subsys->lock#2);
>                                 lock(&ns->pr.pr_lock);
>                                 lock(&subsys->lock#2);
>    lock(&ns->pr.pr_lock);
>
>   *** DEADLOCK ***
>
> 4 locks held by check/1061:
>   #0: ffff88813a8e8418 (sb_writers#14){.+.+}-{0:0}, at: ksys_write+0xf7/0x1d0
>   #1: ffff88811e893a88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x73/0x460
>   #2: ffff88812e673978 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x1db/0x460
>   #3: ffff888110cf7070 (&subsys->lock#2){+.+.}-{3:3}, at: nvmet_ns_disable+0x2a2/0x4a0 [nvmet]
>
> stack backtrace:
> CPU: 0 PID: 1061 Comm: check Not tainted 6.7.0+ #142
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
> Call Trace:
>   <TASK>
>   dump_stack_lvl+0x57/0x90
>   check_noncircular+0x309/0x3f0
>   ? __pfx_check_noncircular+0x10/0x10
>   ? lockdep_lock+0xca/0x1c0
>   ? __pfx_lockdep_lock+0x10/0x10
>   ? lock_release+0x378/0x650
>   ? __stack_depot_save+0x246/0x470
>   __lock_acquire+0x2e96/0x5f40
>   ? __pfx___lock_acquire+0x10/0x10
>   lock_acquire+0x1a9/0x4e0
>   ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>   ? __pfx_lock_acquire+0x10/0x10
>   ? lock_is_held_type+0xce/0x120
>   ? __pfx_lock_acquire+0x10/0x10
>   ? __pfx___might_resched+0x10/0x10
>   __mutex_lock+0x185/0x18c0
>   ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>   ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>   ? rcu_is_watching+0x11/0xb0
>   ? __mutex_lock+0x2a2/0x18c0
>   ? __pfx___mutex_lock+0x10/0x10
>   ? nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>   nvmet_pr_exit_ns+0x2e/0x230 [nvmet]
>   nvmet_ns_disable+0x313/0x4a0 [nvmet]
>   ? __pfx_nvmet_ns_disable+0x10/0x10 [nvmet]
>   nvmet_ns_enable_store+0x8a/0xe0 [nvmet]
>   ? __pfx_nvmet_ns_enable_store+0x10/0x10 [nvmet]
>   configfs_write_iter+0x2ae/0x460
>   vfs_write+0x540/0xd90
>   ? __pfx_vfs_write+0x10/0x10
>   ? __pfx___lock_acquire+0x10/0x10
>   ? __handle_mm_fault+0x12c5/0x1870
>   ? __fget_light+0x51/0x220
>   ksys_write+0xf7/0x1d0
>   ? __pfx_ksys_write+0x10/0x10
>   ? syscall_enter_from_user_mode+0x22/0x90
>   do_syscall_64+0x60/0xe0
>   ? __pfx_lock_release+0x10/0x10
>   ? count_memcg_events.constprop.0+0x4a/0x60
>   ? handle_mm_fault+0x1b1/0x9d0
>   ? exc_page_fault+0xc0/0x100
>   ? rcu_is_watching+0x11/0xb0
>   ? asm_exc_page_fault+0x22/0x30
>   ? lockdep_hardirqs_on+0x7d/0x100
>   entry_SYSCALL_64_after_hwframe+0x6e/0x76
> RIP: 0033:0x7f604525ac34
> Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d 35 77 0d 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
> RSP: 002b:00007ffec7fd6ce8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f604525ac34
> RDX: 0000000000000002 RSI: 0000562b0cd805a0 RDI: 0000000000000001
> RBP: 00007ffec7fd6d10 R08: 0000000000001428 R09: 0000000100000000
> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
> R13: 0000562b0cd805a0 R14: 00007f604532b5c0 R15: 00007f6045328f20
>   </TASK>

Thanks a lot, I will fix this in my reservation patch set v5.

Best regards,

Guixin Liu