[LTP] [PATCH v5 1/2] OVL_MNT: add helpers to setup overlayfs mountpoint

[Murphy Zhou <xzhou@redhat.com>]

On Wed, May 29, 2019 at 01:59:15PM +0300, Amir Goldstein wrote:
> On Wed, May 29, 2019 at 1:19 PM Murphy Zhou <xzhou@redhat.com> wrote:
> >
> > Introduce tst_test->needs_overlay;
> > Define constraints of needed overlayfs dirs;
> > create_overlay_dirs() to create lower/upper/work dirs;
> > mount_overlay() to mount overlayfs;
> > SAFE_MOUNT_OVERLAY macro to mount overlayfs safely, tst_brk TCONF
> > if mount fail with errno ENODEV;
> > TST_MOUNT_OVERLAY  macro to mount overlayfs and return 0 if succeeds;
> >
> > Suggested-by: Petr Vorel <pvorel@suse.cz>
> > Suggested-by: Amir Goldstein <amir73il@gmail.com>
> > Signed-off-by: Murphy Zhou <xzhou@redhat.com>
> > ---
> 
> Very nice! just one minor comment, otherwise

Thank you very much!

> 
> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> 
> > v5:
> >   Introduce tst_test->needs_overlay to mount and umount overlay
> >   Several other fixes suggested by Petr
> >   Update execveat03, inotify07/8 to use needs_overlay
> > v4:
> >   Update ENODEV handle logic
> >   Define TST_MOUNT_OVERLAY and SAFE_MOUNT_OVERLAY macros
> >   Change helper names
> > v3:
> >   Split setup to 2 parts: creating files and mounting.
> >   Use macro SAFE_MOUNT_OVERLAYFS.
> >   Handle ENODEV differently for 4 testcases we have modified.
> > v2:
> >   define constraints in header file.
> >   add a setup helper to create dirs and mount.
> >  include/safe_file_ops_fn.h  |  4 ++++
> >  include/tst_fs.h            |  6 +++++
> >  include/tst_safe_file_ops.h |  6 +++++
> >  include/tst_test.h          |  1 +
> >  lib/tst_fs_setup.c          | 48 +++++++++++++++++++++++++++++++++++++
> >  lib/tst_test.c              | 15 ++++++++++++
> >  6 files changed, 80 insertions(+)
> >  create mode 100644 lib/tst_fs_setup.c
> >
> > diff --git a/include/safe_file_ops_fn.h b/include/safe_file_ops_fn.h
> > index 35ec4fb1f..052fb1b9a 100644
> > --- a/include/safe_file_ops_fn.h
> > +++ b/include/safe_file_ops_fn.h
> > @@ -76,4 +76,8 @@ void safe_touch(const char *file, const int lineno,
> >                 const char *pathname,
> >                 mode_t mode, const struct timespec times[2]);
> >
> > +/* helper functions to setup overlayfs mountpoint */
> > +void create_overlay_dirs(void);
> > +int mount_overlay(const char *file, const int lineno, int skip);
> > +
> >  #endif /* SAFE_FILE_OPS_FN */
> > diff --git a/include/tst_fs.h b/include/tst_fs.h
> > index b2b19ada6..ebca065c6 100644
> > --- a/include/tst_fs.h
> > +++ b/include/tst_fs.h
> > @@ -50,6 +50,12 @@ enum {
> >         TST_GB = 1073741824,
> >  };
> >
> > +#define OVL_BASE_MNTPOINT        "mntpoint"
> > +#define OVL_LOWER      OVL_BASE_MNTPOINT"/lower"
> > +#define OVL_UPPER      OVL_BASE_MNTPOINT"/upper"
> > +#define OVL_WORK       OVL_BASE_MNTPOINT"/work"
> > +#define OVL_MNT                OVL_BASE_MNTPOINT"/ovl"
> > +
> >  /*
> >   * @path: path is the pathname of any file within the mounted file system
> >   * @mult: mult should be TST_KB, TST_MB or TST_GB
> > diff --git a/include/tst_safe_file_ops.h b/include/tst_safe_file_ops.h
> > index 5c3fea4e2..b62a7447f 100644
> > --- a/include/tst_safe_file_ops.h
> > +++ b/include/tst_safe_file_ops.h
> > @@ -59,4 +59,10 @@
> >         safe_touch(__FILE__, __LINE__, NULL, \
> >                         (pathname), (mode), (times))
> >
> > +#define SAFE_MOUNT_OVERLAY() \
> > +       ((void) mount_overlay(__FILE__, __LINE__, 1))
> > +
> > +#define TST_MOUNT_OVERLAY() \
> > +       (mount_overlay(__FILE__, __LINE__, 0) == 0)
> > +
> >  #endif /* TST_SAFE_FILE_OPS */
> > diff --git a/include/tst_test.h b/include/tst_test.h
> > index e4b935c45..f3b8901a2 100644
> > --- a/include/tst_test.h
> > +++ b/include/tst_test.h
> > @@ -121,6 +121,7 @@ struct tst_test {
> >         int needs_root:1;
> >         int forks_child:1;
> >         int needs_device:1;
> > +       int needs_overlay:1;
> >         int needs_checkpoints:1;
> >         int format_device:1;
> >         int mount_device:1;
> > diff --git a/lib/tst_fs_setup.c b/lib/tst_fs_setup.c
> > new file mode 100644
> > index 000000000..e8ae929d7
> > --- /dev/null
> > +++ b/lib/tst_fs_setup.c
> > @@ -0,0 +1,48 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +
> > +#include <dirent.h>
> > +#include <errno.h>
> > +#include <sys/mount.h>
> > +
> > +#define TST_NO_DEFAULT_MAIN
> > +#include "tst_test.h"
> > +#include "tst_fs.h"
> > +
> > +#define TST_FS_SETUP_OVERLAYFS_MSG "overlayfs is not configured in this kernel"
> > +#define TST_FS_SETUP_OVERLAYFS_CONFIG "lowerdir="OVL_LOWER",upperdir="OVL_UPPER",workdir="OVL_WORK
> > +
> > +void create_overlay_dirs(void)
> > +{
> > +       DIR *dir = opendir(OVL_LOWER);
> > +       if (dir == NULL) {
> > +               SAFE_MKDIR(OVL_LOWER, 0755);
> > +               SAFE_MKDIR(OVL_UPPER, 0755);
> > +               SAFE_MKDIR(OVL_WORK, 0755);
> > +               SAFE_MKDIR(OVL_MNT, 0755);
> 
> return here so we don't closedir(NULL)?

Sure! This needs to be fixed. Good catch!

I'll send v6 with this fix and adding your Reivewed-by.

Thank Amir and Petr very much!

--
Murphy

> 
> > +       }
> > +       closedir(dir);
> > +}
> > +
> 
> Thanks for doing this work!
> Amir.