[PATCH 0/2] blktests: New loop tests

[PATCH 0/2] blktests: New loop tests

[Jan Kara]

Hello,

these two patches create two new tests for blktests as regression tests
for my recently posted loopback device fixes. More details in individual
patches.

								Honza

[PATCH 1/2] loop/006: Add test for setting partscan flag

[Jan Kara]

Add test for setting partscan flag.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 src/Makefile                   |  3 ++-
 src/loop_set_status_partscan.c | 45 ++++++++++++++++++++++++++++++++++++++++++
 tests/loop/006                 | 33 +++++++++++++++++++++++++++++++
 tests/loop/006.out             |  2 ++
 4 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 src/loop_set_status_partscan.c
 create mode 100755 tests/loop/006
 create mode 100644 tests/loop/006.out

diff --git a/src/Makefile b/src/Makefile
index f89f61701179..6dadcbec8beb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -4,7 +4,8 @@ C_TARGETS := \
 	openclose \
 	sg/dxfer-from-dev \
 	sg/syzkaller1 \
-	nbdsetsize
+	nbdsetsize \
+	loop_set_status_partscan
 
 CXX_TARGETS := \
 	discontiguous-io
diff --git a/src/loop_set_status_partscan.c b/src/loop_set_status_partscan.c
new file mode 100644
index 000000000000..8873a12e4334
--- /dev/null
+++ b/src/loop_set_status_partscan.c
@@ -0,0 +1,45 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/loop.h>
+
+void usage(const char *progname)
+{
+	fprintf(stderr, "usage: %s PATH\n", progname);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, char **argv)
+{
+	int ret;
+	int fd;
+	struct loop_info64 info;
+
+	if (argc != 2)
+		usage(argv[0]);
+
+	fd = open(argv[1], O_RDONLY);
+	if (fd == -1) {
+		perror("open");
+		return EXIT_FAILURE;
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.lo_flags = LO_FLAGS_PARTSCAN;
+	memcpy(info.lo_file_name, "part", 5);
+
+	ret = ioctl(fd, LOOP_SET_STATUS64, &info);
+	if (ret == -1) {
+		perror("ioctl");
+		close(fd);
+		return EXIT_FAILURE;
+	}
+	close(fd);
+	return EXIT_SUCCESS;
+}
diff --git a/tests/loop/006 b/tests/loop/006
new file mode 100755
index 000000000000..e468d3a20210
--- /dev/null
+++ b/tests/loop/006
@@ -0,0 +1,33 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2018 Jan Kara
+#
+# Regression test for patch "loop: Fix deadlock when calling
+# blkdev_reread_part()". We check whether setting partscan flag
+# and thus forcing partition reread won't trigger lockdep warning.
+#
+
+. tests/loop/rc
+
+DESCRIPTION="check for partition rereading deadlock"
+
+QUICK=1
+
+requires() {
+	_have_src_program loop_set_status_partscan
+}
+
+test() {
+	local loop_dev
+	echo "Running ${TEST_NAME}"
+
+	truncate -s 1M "$TMPDIR/file"
+	if ! loop_dev="$(losetup -f --show "$TMPDIR/file")"; then
+		return 1
+	fi
+
+	src/loop_set_status_partscan "$loop_dev"
+	losetup -d "$loop_dev"
+
+	echo "Test complete"
+}
diff --git a/tests/loop/006.out b/tests/loop/006.out
new file mode 100644
index 000000000000..50bf833f77b0
--- /dev/null
+++ b/tests/loop/006.out
@@ -0,0 +1,2 @@
+Running loop/006
+Test complete
-- 
2.16.4

[PATCH 2/2] loop/007: Add test for oops during backing file verification

[Jan Kara]

Add regression test for patch "block/loop: Use global lock for ioctl()
operation." where we can oops while traversing list of loop devices
backing newly created device.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 src/Makefile         |  3 ++-
 src/loop_change_fd.c | 48 +++++++++++++++++++++++++++++++++
 tests/loop/007       | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/loop/007.out   |  2 ++
 4 files changed, 127 insertions(+), 1 deletion(-)
 create mode 100644 src/loop_change_fd.c
 create mode 100755 tests/loop/007
 create mode 100644 tests/loop/007.out

diff --git a/src/Makefile b/src/Makefile
index 6dadcbec8beb..acd169718b7d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -5,7 +5,8 @@ C_TARGETS := \
 	sg/dxfer-from-dev \
 	sg/syzkaller1 \
 	nbdsetsize \
-	loop_set_status_partscan
+	loop_set_status_partscan \
+	loop_change_fd
 
 CXX_TARGETS := \
 	discontiguous-io
diff --git a/src/loop_change_fd.c b/src/loop_change_fd.c
new file mode 100644
index 000000000000..b124d829f380
--- /dev/null
+++ b/src/loop_change_fd.c
@@ -0,0 +1,48 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/loop.h>
+
+void usage(const char *progname)
+{
+	fprintf(stderr, "usage: %s LOOPDEV PATH\n", progname);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, char **argv)
+{
+	int ret;
+	int fd, filefd;
+
+	if (argc != 3)
+		usage(argv[0]);
+
+	fd = open(argv[1], O_RDWR);
+	if (fd == -1) {
+		perror("open");
+		return EXIT_FAILURE;
+	}
+
+	filefd = open(argv[2], O_RDWR);
+	if (filefd == -1) {
+		perror("open");
+		return EXIT_FAILURE;
+	}
+
+	ret = ioctl(fd, LOOP_CHANGE_FD, filefd);
+	if (ret == -1) {
+		perror("ioctl");
+		close(fd);
+		close(filefd);
+		return EXIT_FAILURE;
+	}
+	close(fd);
+	close(filefd);
+	return EXIT_SUCCESS;
+}
diff --git a/tests/loop/007 b/tests/loop/007
new file mode 100755
index 000000000000..98e4edbe7afa
--- /dev/null
+++ b/tests/loop/007
@@ -0,0 +1,75 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2018 Jan Kara
+#
+# Regression test for patch "block/loop: Use global lock for ioctl() operation."
+# We swap file (through LOOP_CHANGE_FD) under one loopback device while
+# creating and deleting another loopback device pointing to the first one.
+# This checks for races in validation of backing fd.
+
+. tests/loop/rc
+
+DESCRIPTION="check for crash when validating new loop file"
+
+# Try for some time to trigger the race
+TIMED=1
+
+requires() {
+	_have_src_program loop_change_fd
+}
+
+# Setup and tear down loop device pointing to loop_dev
+run_setter() {
+	loop_dev="$1"
+
+	while top_dev=$(losetup -f --show "$loop_dev"); do
+		losetup -d "$top_dev"
+	done
+}
+
+# Switch backing file of loop_dev continuously
+run_switcher() {
+	loop_dev="$1"
+
+	i=1
+	while src/loop_change_fd "$loop_dev" "$TMPDIR/file$i"; do
+		i=$(((i+1)%2))
+	done
+}
+
+test() {
+	echo "Running ${TEST_NAME}"
+
+	timeout=${TIMEOUT:-30}
+
+	truncate -s 1M "$TMPDIR/file0"
+	truncate -s 1M "$TMPDIR/file1"
+
+	if ! loop_dev="$(losetup -r -f --show "$TMPDIR/file0")"; then
+		return 1
+	fi
+
+	run_switcher "$loop_dev" &
+	switch_pid=$!
+	run_setter "$loop_dev" &
+	set_pid=$!
+
+	sleep $timeout
+
+	# Discard KILLED messages from bash...
+	{
+		kill -9 $switch_pid
+		kill -9 $set_pid
+		wait
+		sleep 1
+	} 2>/dev/null
+
+	# Clean up devices
+	top_dev=$(losetup -j "$loop_dev" | sed -e 's/\([^:]*\): .*/\1/')
+	if [[ -n "$top_dev" ]]; then
+		losetup -d "$top_dev"
+	fi
+	losetup -d "$loop_dev"
+
+	echo "Test complete"
+}
diff --git a/tests/loop/007.out b/tests/loop/007.out
new file mode 100644
index 000000000000..32752934d48a
--- /dev/null
+++ b/tests/loop/007.out
@@ -0,0 +1,2 @@
+Running loop/007
+Test complete
-- 
2.16.4

Re: [PATCH 1/2] loop/006: Add test for setting partscan flag

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

Re: [PATCH 2/2] loop/007: Add test for oops during backing file verification

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

Re: [PATCH 1/2] loop/006: Add test for setting partscan flag

[Omar Sandoval]

On Thu, Oct 18, 2018 at 12:31:46PM +0200, Jan Kara wrote:
> Add test for setting partscan flag.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Sorry I didn't notice this earlier, but loop/001 already does a
partition rescan (via losetup -P). Does that cover this test case?

> ---
>  src/Makefile                   |  3 ++-
>  src/loop_set_status_partscan.c | 45 ++++++++++++++++++++++++++++++++++++++++++
>  tests/loop/006                 | 33 +++++++++++++++++++++++++++++++
>  tests/loop/006.out             |  2 ++
>  4 files changed, 82 insertions(+), 1 deletion(-)
>  create mode 100644 src/loop_set_status_partscan.c
>  create mode 100755 tests/loop/006
>  create mode 100644 tests/loop/006.out
> 
> diff --git a/src/Makefile b/src/Makefile
> index f89f61701179..6dadcbec8beb 100644
> --- a/src/Makefile
> +++ b/src/Makefile
> @@ -4,7 +4,8 @@ C_TARGETS := \
>  	openclose \
>  	sg/dxfer-from-dev \
>  	sg/syzkaller1 \
> -	nbdsetsize
> +	nbdsetsize \
> +	loop_set_status_partscan
>  
>  CXX_TARGETS := \
>  	discontiguous-io
> diff --git a/src/loop_set_status_partscan.c b/src/loop_set_status_partscan.c
> new file mode 100644
> index 000000000000..8873a12e4334
> --- /dev/null
> +++ b/src/loop_set_status_partscan.c
> @@ -0,0 +1,45 @@
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/ioctl.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <linux/loop.h>
> +
> +void usage(const char *progname)
> +{
> +	fprintf(stderr, "usage: %s PATH\n", progname);
> +	exit(EXIT_FAILURE);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +	int ret;
> +	int fd;
> +	struct loop_info64 info;
> +
> +	if (argc != 2)
> +		usage(argv[0]);
> +
> +	fd = open(argv[1], O_RDONLY);
> +	if (fd == -1) {
> +		perror("open");
> +		return EXIT_FAILURE;
> +	}
> +
> +	memset(&info, 0, sizeof(info));
> +	info.lo_flags = LO_FLAGS_PARTSCAN;
> +	memcpy(info.lo_file_name, "part", 5);

What's the significance of this file name?

> +	ret = ioctl(fd, LOOP_SET_STATUS64, &info);
> +	if (ret == -1) {
> +		perror("ioctl");
> +		close(fd);
> +		return EXIT_FAILURE;
> +	}
> +	close(fd);
> +	return EXIT_SUCCESS;
> +}

[snip]

Re: [PATCH 2/2] loop/007: Add test for oops during backing file verification

[Omar Sandoval]

On Thu, Oct 18, 2018 at 12:31:47PM +0200, Jan Kara wrote:
> Add regression test for patch "block/loop: Use global lock for ioctl()
> operation." where we can oops while traversing list of loop devices
> backing newly created device.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Looks good, sans a missing addition to src/.gitignore. I can fix that
and apply this once I hear back regarding the other test.

Re: [PATCH 1/2] loop/006: Add test for setting partscan flag

[Jan Kara]

On Mon 22-10-18 15:52:55, Omar Sandoval wrote:
> On Thu, Oct 18, 2018 at 12:31:46PM +0200, Jan Kara wrote:
> > Add test for setting partscan flag.
> > 
> > Signed-off-by: Jan Kara <jack@suse.cz>
> 
> Sorry I didn't notice this earlier, but loop/001 already does a
> partition rescan (via losetup -P). Does that cover this test case?

Yes I know. But the partition rescanning on device creation has been
handled properly while partition rescanning as a result of LOOP_SET_STATUS
was buggy. That's why I've added this test.

> > +int main(int argc, char **argv)
> > +{
> > +	int ret;
> > +	int fd;
> > +	struct loop_info64 info;
> > +
> > +	if (argc != 2)
> > +		usage(argv[0]);
> > +
> > +	fd = open(argv[1], O_RDONLY);
> > +	if (fd == -1) {
> > +		perror("open");
> > +		return EXIT_FAILURE;
> > +	}
> > +
> > +	memset(&info, 0, sizeof(info));
> > +	info.lo_flags = LO_FLAGS_PARTSCAN;
> > +	memcpy(info.lo_file_name, "part", 5);
> 
> What's the significance of this file name?

Probably none, I guess I can just delete it. I think I've just copy-pasted
it from some other test excercising LOOP_SET_STATUS...

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 1/2] loop/006: Add test for setting partscan flag

[Omar Sandoval]

On Tue, Oct 23, 2018 at 12:05:12PM +0200, Jan Kara wrote:
> On Mon 22-10-18 15:52:55, Omar Sandoval wrote:
> > On Thu, Oct 18, 2018 at 12:31:46PM +0200, Jan Kara wrote:
> > > Add test for setting partscan flag.
> > > 
> > > Signed-off-by: Jan Kara <jack@suse.cz>
> > 
> > Sorry I didn't notice this earlier, but loop/001 already does a
> > partition rescan (via losetup -P). Does that cover this test case?
> 
> Yes I know. But the partition rescanning on device creation has been
> handled properly while partition rescanning as a result of LOOP_SET_STATUS
> was buggy. That's why I've added this test.

At least here, losetup -P does a LOOP_SET_STATUS:

$ sudo strace -e ioctl losetup -f --show -P test.img
ioctl(3, LOOP_CTL_GET_FREE)             = 0
ioctl(4, LOOP_SET_FD, 3)                = 0
ioctl(4, LOOP_SET_STATUS64, {lo_offset=0, lo_number=0, lo_flags=LO_FLAGS_PARTSCAN, lo_file_name="/home/osandov/test.img", ...}) = 0
/dev/loop0
+++ exited with 0 +++

Re: [PATCH 1/2] loop/006: Add test for setting partscan flag

[Jan Kara]

On Tue 23-10-18 11:57:50, Omar Sandoval wrote:
> On Tue, Oct 23, 2018 at 12:05:12PM +0200, Jan Kara wrote:
> > On Mon 22-10-18 15:52:55, Omar Sandoval wrote:
> > > On Thu, Oct 18, 2018 at 12:31:46PM +0200, Jan Kara wrote:
> > > > Add test for setting partscan flag.
> > > > 
> > > > Signed-off-by: Jan Kara <jack@suse.cz>
> > > 
> > > Sorry I didn't notice this earlier, but loop/001 already does a
> > > partition rescan (via losetup -P). Does that cover this test case?
> > 
> > Yes I know. But the partition rescanning on device creation has been
> > handled properly while partition rescanning as a result of LOOP_SET_STATUS
> > was buggy. That's why I've added this test.
> 
> At least here, losetup -P does a LOOP_SET_STATUS:
> 
> $ sudo strace -e ioctl losetup -f --show -P test.img
> ioctl(3, LOOP_CTL_GET_FREE)             = 0
> ioctl(4, LOOP_SET_FD, 3)                = 0
> ioctl(4, LOOP_SET_STATUS64, {lo_offset=0, lo_number=0, lo_flags=LO_FLAGS_PARTSCAN, lo_file_name="/home/osandov/test.img", ...}) = 0
> /dev/loop0
> +++ exited with 0 +++

Right, my bad. Just discard this test then. Thanks for noticing this!

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 0/2] blktests: New loop tests

[Omar Sandoval]

On Thu, Oct 18, 2018 at 12:31:45PM +0200, Jan Kara wrote:
> 
> Hello,
> 
> these two patches create two new tests for blktests as regression tests
> for my recently posted loopback device fixes. More details in individual
> patches.

Thanks, Jan, I applied 007 renamed to 006.