On Wed, Aug 4, 2021 at 7:52 AM Gabriel Krisman Bertazi
<krisman@xxxxxxxxxxxxx> wrote:
>
> Amir Goldstein <amir73il@xxxxxxxxx> writes:
>
> > On Tue, Aug 3, 2021 at 12:47 AM Gabriel Krisman Bertazi
> > <krisman@xxxxxxxxxxxxx> wrote:
> >>
> >> This test corrupts an inode entry with an invalid mode through debugfs
> >> and then tries to access it. This should result in a ext4 error, which
> >> we monitor through the fanotify group.
> >>
> >> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
> >> ---
> >> .../kernel/syscalls/fanotify/fanotify20.c | 38 +++++++++++++++++++
> >> 1 file changed, 38 insertions(+)
> >>
> >> diff --git a/testcases/kernel/syscalls/fanotify/fanotify20.c b/testcases/kernel/syscalls/fanotify/fanotify20.c
> >> index e7ced28eb61d..0c63e90edc3a 100644
> >> --- a/testcases/kernel/syscalls/fanotify/fanotify20.c
> >> +++ b/testcases/kernel/syscalls/fanotify/fanotify20.c
> >> @@ -76,6 +76,36 @@ static void trigger_fs_abort(void)
> >> MS_REMOUNT|MS_RDONLY, "abort");
> >> }
> >>
> >> +#define TCASE2_BASEDIR "tcase2"
> >> +#define TCASE2_BAD_DIR TCASE2_BASEDIR"/bad_dir"
> >> +
> >> +static unsigned int tcase2_bad_ino;
> >> +static void tcase2_prepare_fs(void)
> >> +{
> >> + struct stat stat;
> >> +
> >> + SAFE_MKDIR(MOUNT_PATH"/"TCASE2_BASEDIR, 0777);
> >> + SAFE_MKDIR(MOUNT_PATH"/"TCASE2_BAD_DIR, 0777);
> >> +
> >> + SAFE_STAT(MOUNT_PATH"/"TCASE2_BAD_DIR, &stat);
> >> + tcase2_bad_ino = stat.st_ino;
> >> +
> >> + SAFE_UMOUNT(MOUNT_PATH);
> >> + do_debugfs_request(tst_device->dev, "sif " TCASE2_BAD_DIR " mode 0xff");
> >> + SAFE_MOUNT(tst_device->dev, MOUNT_PATH, tst_device->fs_type, 0, NULL);
> >> +}
> >> +
> >> +static void tcase2_trigger_lookup(void)
> >> +{
> >> + int ret;
> >> +
> >> + /* SAFE_OPEN cannot be used here because we expect it to fail. */
> >> + ret = open(MOUNT_PATH"/"TCASE2_BAD_DIR, O_RDONLY, 0);
> >> + if (ret != -1 && errno != EUCLEAN)
> >> + tst_res(TFAIL, "Unexpected lookup result(%d) of %s (%d!=%d)",
> >> + ret, TCASE2_BAD_DIR, errno, EUCLEAN);
> >> +}
> >> +
> >> static const struct test_case {
> >> char *name;
> >> int error;
> >> @@ -92,6 +122,14 @@ static const struct test_case {
> >> .error_count = 1,
> >> .error = EXT4_ERR_ESHUTDOWN,
> >> .inode = NULL
> >> + },
> >> + {
> >> + .name = "Lookup of inode with invalid mode",
> >> + .prepare_fs = tcase2_prepare_fs,
> >> + .trigger_error = &tcase2_trigger_lookup,
> >> + .error_count = 1,
> >> + .error = 0,
> >> + .inode = &tcase2_bad_ino,
> >
> > Why is error 0?
> > What's the rationale?
>
> Hi Amir,
>
> That is specific to Ext4. Some ext4 conditions report bogus error codes. I will
> come up with a kernel patch changing it.
>
Well, I would not expect a FAN_FS_ERROR event to ever have 0 error
value. Since this test practically only tests ext4, I do not think it
is reasonable
for the test to VERIFY a bug. It is fine to write this test with expectations
that are not met and let it fail.
But a better plan would probably be to merge the patches up to 5 to test
FAN_FS_ERROR and then add more test cases after ext4 is fixed
Either that or you fix the ext4 problem along with FAN_FS_ERROR.
Forgot to say that the test needs to declare .needs_cmds "debugfs".
In any case, as far as prerequisite to merging FAN_FS_ERROR
your WIP tests certainly suffice.
Please keep your test branch around so we can use it to validate
the kernel patches.
I usually hold off on submitting LTP tests for inclusion until at least -rc3
after kernel patches have been merged.
Thanks,
Amir.
