[LTP] [PATCH v3 0/2] libltp: add support for .needs_rofs for EROFS check

[LTP] [PATCH v3 0/2] libltp: add support for .needs_rofs for EROFS check

[Sandeep Patil]

Some tests go through losetup, create, format and mount
filesystems only to run tests for 'EROFS' return value from
system calls. The tests end up being flaky depending on the tools
available on the platform. e.g. mkfs.<filesystem> tool is required for 
mounting a device with filesystem.

If the test is only to check for EROFS, this can be achieved by simply doing a
'tmpfs' read-only mount in $tmpdir. So, this series adds a ".needs_rofs" flag
to 'struct tst_test' that can be used to indicate that the test only needs a
read-only filesystem mount ot test for 'EROFS' return value. If the flag is
set, the library will first attempt to mount 'tmpfs' filesystem at
tst_test->mntpoint and fallback to the original create, format and mount a
loopback device if that fails.

Example of tests that can benefit from this are:
  access04, mkdirat02, mknodat02, acct01, fchown04, mknod07 etc.

This also allows for these tests to successfully run on Android.

Sandeep Patil (2):
  libltp: add support to mount tmpfs for EROFS testing
  syscalls/access04: use .needs_rofs flag for EROFS testing

 include/tst_test.h                          |  1 +
 lib/tst_test.c                              | 36 ++++++++++++++++++++++++-----
 testcases/kernel/syscalls/access/access04.c |  3 +--
 3 files changed, 32 insertions(+), 8 deletions(-)

-- 
2.14.1.690.gbb1197296e-goog

[LTP] [RESEND][PATCH v3 1/2] libltp: add support to mount tmpfs for EROFS testing

[Sandeep Patil]

Some tests go through losetup, create, format and mount filesystems only
to test for 'EROFS' return value from system calls. The tests end up
being flaky depending on the tools available on the platform. e.g.
mkfs.<filesystem> tool is required for mounting a device with
filesystem.

If the test is only to check for EROFS, this can be achieved by simply
by the bind mounting (MS_BIND) for '/' on 'mntpoint' and then remount
the same as 'read-only'.

Example of tests that can benefit from this are:
  access04, mkdirat02, mknodat02, acct01, fchown04, mknod07 etc.

This also allows for these tests to successfully run on Android.

Signed-off-by: Sandeep Patil <sspatil@google.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
---
v2->v3
------
- Added Tested-by from Jan Stancek

v1->v2
------
- Changed the interface to be at a higher level, i.e. instead of
  making tests specify that they need a read-only tmpfs mount, we
  do that automatically in the library as a preference and fallback
  to the old way if that doesn't succeed.

- The read-only bind mount of "/" option was tried and it worked just
  fine with an Android system, but broke my ubuntu instance badly (I lost root).
  I could never find out why, since hte patch worked fine on Android
  and it correctly did the bind mount. However, I figured if there is any 
  chance of possible breakage, we should simply avoid that path for now.
 include/tst_test.h |  1 +
 lib/tst_test.c     | 36 ++++++++++++++++++++++++++++++------
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/include/tst_test.h b/include/tst_test.h
index e90312ae3..ad468e8cf 100644
--- a/include/tst_test.h
+++ b/include/tst_test.h
@@ -124,6 +124,7 @@ struct tst_test {
 	int needs_checkpoints:1;
 	int format_device:1;
 	int mount_device:1;
+	int needs_rofs:1;
 
 	/* Minimal device size in megabytes */
 	unsigned int dev_min_size;
diff --git a/lib/tst_test.c b/lib/tst_test.c
index 4c30edab5..828eae49d 100644
--- a/lib/tst_test.c
+++ b/lib/tst_test.c
@@ -21,6 +21,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/time.h>
@@ -41,7 +42,7 @@ struct tst_test *tst_test;
 static int iterations = 1;
 static float duration = -1;
 static pid_t main_pid, lib_pid;
-static int device_mounted;
+static int mntpoint_active;
 
 struct results {
 	int passed;
@@ -701,7 +702,32 @@ static void do_setup(int argc, char *argv[])
 	if (needs_tmpdir() && !tst_tmpdir_created())
 		tst_tmpdir();
 
-	if (tst_test->needs_device) {
+	if (tst_test->mntpoint)
+		SAFE_MKDIR(tst_test->mntpoint, 0777);
+
+	if (tst_test->needs_rofs) {
+		if (!tst_test->mntpoint) {
+			tst_brk(TBROK,
+				"tst_test->mntpoint must be set!");
+		}
+
+		/* If we failed to do read-only bind mount for '/'. Fallback to
+		 * using a device with empty read-only filesystem.
+		 */
+		if (mount(NULL, tst_test->mntpoint, "tmpfs", MS_RDONLY, NULL)) {
+			tst_res(TINFO, "Cannot mount tmpfs read-only at %s, "
+					"setting up a device instead\n",
+					tst_test->mntpoint);
+			tst_test->mount_device = 1;
+			tst_test->needs_device = 1;
+			tst_test->format_device = 1;
+			tst_test->mnt_flags = MS_RDONLY;
+		} else {
+			mntpoint_active = 1;
+		}
+	}
+
+	if (tst_test->needs_device && !mntpoint_active) {
 		tdev.dev = tst_acquire_device_(NULL, tst_test->dev_min_size);
 
 		if (!tdev.dev)
@@ -721,16 +747,14 @@ static void do_setup(int argc, char *argv[])
 		}
 
 		if (tst_test->mount_device) {
-
 			if (!tst_test->mntpoint) {
 				tst_brk(TBROK,
 					"tst_test->mntpoint must be set!");
 			}
 
-			SAFE_MKDIR(tst_test->mntpoint, 0777);
 			SAFE_MOUNT(tdev.dev, tst_test->mntpoint, tdev.fs_type,
 				   tst_test->mnt_flags, tst_test->mnt_data);
-			device_mounted = 1;
+			mntpoint_active = 1;
 		}
 	}
 
@@ -751,7 +775,7 @@ static void do_test_setup(void)
 
 static void do_cleanup(void)
 {
-	if (device_mounted)
+	if (mntpoint_active)
 		tst_umount(tst_test->mntpoint);
 
 	if (tst_test->needs_device && tdev.dev)
-- 
2.14.1.690.gbb1197296e-goog

[LTP] [RESEND][PATCH v3 2/2] syscalls/access04: use .needs_rofs flag for EROFS testing

[Sandeep Patil]

Prefer to use the read-only bind mount of '/' over create,
format and mount a filesystem image for testing 'EROFS' return
value from access()

Signed-off-by: Sandeep Patil <sspatil@google.com>
---
 testcases/kernel/syscalls/access/access04.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/testcases/kernel/syscalls/access/access04.c b/testcases/kernel/syscalls/access/access04.c
index dbb6d271a..626e6df2c 100644
--- a/testcases/kernel/syscalls/access/access04.c
+++ b/testcases/kernel/syscalls/access/access04.c
@@ -125,9 +125,8 @@ static struct tst_test test = {
 	.needs_tmpdir = 1,
 	.needs_root = 1,
 	.forks_child = 1,
-	.mount_device = 1,
+	.needs_rofs = 1,
 	.mntpoint = MNT_POINT,
-	.mnt_flags = MS_RDONLY,
 	.setup = setup,
 	.test = verify_access,
 };
-- 
2.14.1.690.gbb1197296e-goog

[LTP] [RESEND][PATCH v3 1/2] libltp: add support to mount tmpfs for EROFS testing

[Cyril Hrubis]

Hi!
> diff --git a/lib/tst_test.c b/lib/tst_test.c
> index 4c30edab5..828eae49d 100644
> --- a/lib/tst_test.c
> +++ b/lib/tst_test.c
> @@ -21,6 +21,7 @@
>  #include <string.h>
>  #include <stdlib.h>
>  #include <errno.h>
> +#include <sys/mount.h>
>  #include <sys/types.h>
>  #include <sys/wait.h>
>  #include <sys/time.h>
> @@ -41,7 +42,7 @@ struct tst_test *tst_test;
>  static int iterations = 1;
>  static float duration = -1;
>  static pid_t main_pid, lib_pid;
> -static int device_mounted;
> +static int mntpoint_active;

A bit better name would be 'mntpoint_mounted' but that is very minor.

>  struct results {
>  	int passed;
> @@ -701,7 +702,32 @@ static void do_setup(int argc, char *argv[])
>  	if (needs_tmpdir() && !tst_tmpdir_created())
>  		tst_tmpdir();
>  
> -	if (tst_test->needs_device) {
> +	if (tst_test->mntpoint)
> +		SAFE_MKDIR(tst_test->mntpoint, 0777);
> +
> +	if (tst_test->needs_rofs) {
> +		if (!tst_test->mntpoint) {
> +			tst_brk(TBROK,
> +				"tst_test->mntpoint must be set!");
> +		}

We may as well move this check from both branches to the top to avoid
duplication, i.e. add:

	if ((tst_test->needs_rofs || tst_test->mount_device) &&
	    !tst_test->mntpoint) {
		tst_brk(TBROK, "tst_test->mntpoint must be set!");
	}

> +		/* If we failed to do read-only bind mount for '/'. Fallback to
> +		 * using a device with empty read-only filesystem.
> +		 */
> +		if (mount(NULL, tst_test->mntpoint, "tmpfs", MS_RDONLY, NULL)) {
> +			tst_res(TINFO, "Cannot mount tmpfs read-only at %s, "
                                ^
				Maybe we should add | TERRNO here as
				well so that user gets a hint why this
				mount() had failed.
> +					"setting up a device instead\n",
> +					tst_test->mntpoint);
> +			tst_test->mount_device = 1;
> +			tst_test->needs_device = 1;
> +			tst_test->format_device = 1;
> +			tst_test->mnt_flags = MS_RDONLY;
> +		} else {
> +			mntpoint_active = 1;
> +		}
> +	}
> +
> +	if (tst_test->needs_device && !mntpoint_active) {
>  		tdev.dev = tst_acquire_device_(NULL, tst_test->dev_min_size);
>  
>  		if (!tdev.dev)
> @@ -721,16 +747,14 @@ static void do_setup(int argc, char *argv[])
>  		}
>  
>  		if (tst_test->mount_device) {
> -
>  			if (!tst_test->mntpoint) {
>  				tst_brk(TBROK,
>  					"tst_test->mntpoint must be set!");
>  			}
>  
> -			SAFE_MKDIR(tst_test->mntpoint, 0777);
>  			SAFE_MOUNT(tdev.dev, tst_test->mntpoint, tdev.fs_type,
>  				   tst_test->mnt_flags, tst_test->mnt_data);
> -			device_mounted = 1;
> +			mntpoint_active = 1;
>  		}
>  	}
>  
> @@ -751,7 +775,7 @@ static void do_test_setup(void)
>  
>  static void do_cleanup(void)
>  {
> -	if (device_mounted)
> +	if (mntpoint_active)
>  		tst_umount(tst_test->mntpoint);
>  
>  	if (tst_test->needs_device && tdev.dev)

Other than the minor nits it looks good to me.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [RESEND][PATCH v3 2/2] syscalls/access04: use .needs_rofs flag for EROFS testing

[Cyril Hrubis]

Hi!
> Prefer to use the read-only bind mount of '/' over create,
> format and mount a filesystem image for testing 'EROFS' return
> value from access()
> 
> Signed-off-by: Sandeep Patil <sspatil@google.com>
> ---
>  testcases/kernel/syscalls/access/access04.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/access/access04.c b/testcases/kernel/syscalls/access/access04.c
> index dbb6d271a..626e6df2c 100644
> --- a/testcases/kernel/syscalls/access/access04.c
> +++ b/testcases/kernel/syscalls/access/access04.c
> @@ -125,9 +125,8 @@ static struct tst_test test = {
>  	.needs_tmpdir = 1,
>  	.needs_root = 1,
>  	.forks_child = 1,
> -	.mount_device = 1,
> +	.needs_rofs = 1,
>  	.mntpoint = MNT_POINT,
> -	.mnt_flags = MS_RDONLY,
>  	.setup = setup,
>  	.test = verify_access,
>  };

This is obviously correct, how many testcases can use this interface?

Lookint into the git tree, there is at least creat06 that could be
converted in the very same way, then there is a quite a bit of testcases
that will need to be converted to the new test library first.

-- 
Cyril Hrubis
chrubis@suse.cz

[LTP] [RESEND][PATCH v3 2/2] syscalls/access04: use .needs_rofs flag for EROFS testing

[Sandeep Patil]

On Tue, Sep 19, 2017 at 10:47:29AM +0200, Cyril Hrubis wrote:
> Hi!
> > Prefer to use the read-only bind mount of '/' over create,
> > format and mount a filesystem image for testing 'EROFS' return
> > value from access()
> > 
> > Signed-off-by: Sandeep Patil <sspatil@google.com>
> > ---
> >  testcases/kernel/syscalls/access/access04.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/testcases/kernel/syscalls/access/access04.c b/testcases/kernel/syscalls/access/access04.c
> > index dbb6d271a..626e6df2c 100644
> > --- a/testcases/kernel/syscalls/access/access04.c
> > +++ b/testcases/kernel/syscalls/access/access04.c
> > @@ -125,9 +125,8 @@ static struct tst_test test = {
> >  	.needs_tmpdir = 1,
> >  	.needs_root = 1,
> >  	.forks_child = 1,
> > -	.mount_device = 1,
> > +	.needs_rofs = 1,
> >  	.mntpoint = MNT_POINT,
> > -	.mnt_flags = MS_RDONLY,
> >  	.setup = setup,
> >  	.test = verify_access,
> >  };
> 
> This is obviously correct, how many testcases can use this interface?

I had this in the cover letter, but here's the preliminary list of tests
that will end up using .need_rofs.

  access04, mkdirat02, mknodat02, acct01, fchown04, mknod07 etc.

- ssp

> 
> Lookint into the git tree, there is at least creat06 that could be
> converted in the very same way, then there is a quite a bit of testcases
> that will need to be converted to the new test library first.

Ack, I have a list of tests to be converted to new library too. Some of them
also will make those tests run in Android environment, so I shall follow up
with the conversion patches post release too.

- ssp

> 
> -- 
> Cyril Hrubis
> chrubis@suse.cz

[LTP] [RESEND][PATCH v3 1/2] libltp: add support to mount tmpfs for EROFS testing

[Sandeep Patil]

On Tue, Sep 19, 2017 at 10:43:23AM +0200, Cyril Hrubis wrote:
> Hi!
> > diff --git a/lib/tst_test.c b/lib/tst_test.c
> > index 4c30edab5..828eae49d 100644
> > --- a/lib/tst_test.c
> > +++ b/lib/tst_test.c
> > @@ -21,6 +21,7 @@
> >  #include <string.h>
> >  #include <stdlib.h>
> >  #include <errno.h>
> > +#include <sys/mount.h>
> >  #include <sys/types.h>
> >  #include <sys/wait.h>
> >  #include <sys/time.h>
> > @@ -41,7 +42,7 @@ struct tst_test *tst_test;
> >  static int iterations = 1;
> >  static float duration = -1;
> >  static pid_t main_pid, lib_pid;
> > -static int device_mounted;
> > +static int mntpoint_active;
> 
> A bit better name would be 'mntpoint_mounted' but that is very minor.
> 
> >  struct results {
> >  	int passed;
> > @@ -701,7 +702,32 @@ static void do_setup(int argc, char *argv[])
> >  	if (needs_tmpdir() && !tst_tmpdir_created())
> >  		tst_tmpdir();
> >  
> > -	if (tst_test->needs_device) {
> > +	if (tst_test->mntpoint)
> > +		SAFE_MKDIR(tst_test->mntpoint, 0777);
> > +
> > +	if (tst_test->needs_rofs) {
> > +		if (!tst_test->mntpoint) {
> > +			tst_brk(TBROK,
> > +				"tst_test->mntpoint must be set!");
> > +		}
> 
> We may as well move this check from both branches to the top to avoid
> duplication, i.e. add:
> 
> 	if ((tst_test->needs_rofs || tst_test->mount_device) &&
> 	    !tst_test->mntpoint) {
> 		tst_brk(TBROK, "tst_test->mntpoint must be set!");
> 	}
> 
> > +		/* If we failed to do read-only bind mount for '/'. Fallback to
> > +		 * using a device with empty read-only filesystem.
> > +		 */
> > +		if (mount(NULL, tst_test->mntpoint, "tmpfs", MS_RDONLY, NULL)) {
> > +			tst_res(TINFO, "Cannot mount tmpfs read-only at %s, "
>                                 ^
> 				Maybe we should add | TERRNO here as
> 				well so that user gets a hint why this
> 				mount() had failed.
> > +					"setting up a device instead\n",
> > +					tst_test->mntpoint);
> > +			tst_test->mount_device = 1;
> > +			tst_test->needs_device = 1;
> > +			tst_test->format_device = 1;
> > +			tst_test->mnt_flags = MS_RDONLY;
> > +		} else {
> > +			mntpoint_active = 1;
> > +		}
> > +	}
> > +
> > +	if (tst_test->needs_device && !mntpoint_active) {
> >  		tdev.dev = tst_acquire_device_(NULL, tst_test->dev_min_size);
> >  
> >  		if (!tdev.dev)
> > @@ -721,16 +747,14 @@ static void do_setup(int argc, char *argv[])
> >  		}
> >  
> >  		if (tst_test->mount_device) {
> > -
> >  			if (!tst_test->mntpoint) {
> >  				tst_brk(TBROK,
> >  					"tst_test->mntpoint must be set!");
> >  			}
> >  
> > -			SAFE_MKDIR(tst_test->mntpoint, 0777);
> >  			SAFE_MOUNT(tdev.dev, tst_test->mntpoint, tdev.fs_type,
> >  				   tst_test->mnt_flags, tst_test->mnt_data);
> > -			device_mounted = 1;
> > +			mntpoint_active = 1;
> >  		}
> >  	}
> >  
> > @@ -751,7 +775,7 @@ static void do_test_setup(void)
> >  
> >  static void do_cleanup(void)
> >  {
> > -	if (device_mounted)
> > +	if (mntpoint_active)
> >  		tst_umount(tst_test->mntpoint);
> >  
> >  	if (tst_test->needs_device && tdev.dev)
> 
> Other than the minor nits it looks good to me.

ack, I'll spin v4 with the fixes so they are ready in time for release.

- ssp