[PATCH v2 0/9] Tests for idmapped tmpfs

[PATCH v2 0/9] Tests for idmapped tmpfs

[Rodrigo Campos]

This patches add tests for tmpfs idmap mounts inside a userns.

Changes in v2:
	* Added reviewed-by Christian to some patches
	* Clarified commit description on "Fix race condition on get_userns_fd"
	  and removed the noreturn attribute in the function
        * As noted by Christian, we can makedev(0,0) and have that work inside a
          userns. So, simplified patch 6 for that
	* Fixed typo in the #endif comment of vfstest.h
	* Folded adding DIR0 constant into the patch that uses it
	* Fixed the indentation patch to only change one line and not change the
	  usage() section

Similar as before, the first patches are just unrelated simple fixes that I saw
while playing with this:
  vfs: Don't open-code safe_close()
  vfs: Fix documentation typo
  vfs: Use tabs to indent, not spaces
  vfs: Fix race condition on get_userns_fd()

These pave the way to support running core tests within another test (from the
tmpfs suite that we will add):
  vfs: Fix race condition on get_userns_fd()
  vfs: Make switch_userns set PR_SET_DUMPABLE
  vfs: Prepare tests in &s_idmapped_mounts to be reused inside a userns
  vfs: Make idmapped core tests public
  vfs: Export test_setup() and test_cleanup()

As mentioned in the changelog, "vfs: Prepare tests in &s_idmapped_mounts to be
reused inside a userns" is now simplified. Changing only these few places to
mkdev(0, 0) did the trick. These tests are doing a switch_fsids() and that
inside the userns fails if we don't use 0:0 as major/minor.

Just to be super careful, I'd like if Christian can have a look and see if
indeed the places that mknod fails inside a userns and don't make sense.

Can you please take a look at that, Christian? I'm in a hurry and have to catch
a train in a few minutes.

Finally, the suite for idmapped tmpfs is implemented here:
  vfs: Add tmpfs tests for idmap mounts


Best,
Rodrigo

Rodrigo Campos (9):
  vfs: Don't open-code safe_close()
  vfs: Fix documentation typo
  vfs: Use tabs to indent, not spaces
  vfs: Fix race condition on get_userns_fd()
  vfs: Make switch_userns set PR_SET_DUMPABLE
  vfs: Prepare tests in &s_idmapped_mounts to be reused inside a userns
  vfs: Make idmapped core tests public
  vfs: Export test_setup() and test_cleanup()
  vfs: Add tmpfs tests for idmap mounts

 src/vfs/Makefile                |   4 +-
 src/vfs/idmapped-mounts.c       | 140 +++++++--------
 src/vfs/idmapped-mounts.h       |  38 ++++
 src/vfs/tmpfs-idmapped-mounts.c | 298 ++++++++++++++++++++++++++++++++
 src/vfs/tmpfs-idmapped-mounts.h |  15 ++
 src/vfs/utils.c                 |  19 +-
 src/vfs/utils.h                 |   4 +-
 src/vfs/vfstest.c               |  19 +-
 src/vfs/vfstest.h               |  10 ++
 tests/tmpfs/001                 |  27 +++
 tests/tmpfs/001.out             |   2 +
 tests/tmpfs/Makefile            |  24 +++
 12 files changed, 513 insertions(+), 87 deletions(-)
 create mode 100644 src/vfs/tmpfs-idmapped-mounts.c
 create mode 100644 src/vfs/tmpfs-idmapped-mounts.h
 create mode 100644 src/vfs/vfstest.h
 create mode 100755 tests/tmpfs/001
 create mode 100644 tests/tmpfs/001.out
 create mode 100644 tests/tmpfs/Makefile

-- 
2.39.2

[PATCH v2 1/9] vfs: Don't open-code safe_close()

[Rodrigo Campos]

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Reviewed-by: Christian Brauner <brauner@kernel.org>
---
 src/vfs/utils.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git src/vfs/utils.c src/vfs/utils.c
index 8b000506..ea7536c1 100644
--- src/vfs/utils.c
+++ src/vfs/utils.c
@@ -129,10 +129,8 @@ static int write_id_mapping(idmap_type_t map_type, pid_t pid, const char *buf, s
 
 	fret = 0;
 out:
-	if (fd >= 0)
-		close(fd);
-	if (setgroups_fd >= 0)
-		close(setgroups_fd);
+	safe_close(fd);
+	safe_close(setgroups_fd);
 
 	return fret;
 }
-- 
2.39.2

[PATCH v2 2/9] vfs: Fix documentation typo

[Rodrigo Campos]

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Reviewed-by: Christian Brauner <brauner@kernel.org>
---
 src/vfs/utils.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git src/vfs/utils.h src/vfs/utils.h
index c0dbe370..f1681737 100644
--- src/vfs/utils.h
+++ src/vfs/utils.h
@@ -177,7 +177,7 @@ struct vfs_ns_cap_data {
 struct vfstest_info {
 	uid_t t_overflowuid;
 	gid_t t_overflowgid;
-	/* path of the test device */
+	/* Filesystem type of the mountpoint */
 	const char *t_fstype;
 	/* path of the test device */
 	const char *t_device;
-- 
2.39.2

[PATCH v2 3/9] vfs: Use tabs to indent, not spaces

[Rodrigo Campos]

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 src/vfs/vfstest.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git src/vfs/vfstest.c src/vfs/vfstest.c
index 20ade869..a840e007 100644
--- src/vfs/vfstest.c
+++ src/vfs/vfstest.c
@@ -105,7 +105,7 @@ static int hardlink_crossing_mounts(const struct vfstest_info *info)
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
 
-        if (chown_r(info->t_mnt_fd, T_DIR1, 10000, 10000)) {
+	if (chown_r(info->t_mnt_fd, T_DIR1, 10000, 10000)) {
 		log_stderr("failure: chown_r");
 		goto out;
 	}
-- 
2.39.2

Re: [PATCH v2 3/9] vfs: Use tabs to indent, not spaces

[Christian Brauner]

On Wed, Mar 08, 2023 at 12:13:37PM +0100, Rodrigo Campos wrote:
> Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> ---

Looks good,
Reviewed-by: Christian Brauner <brauner@kernel.org>

[PATCH v2 4/9] vfs: Fix race condition on get_userns_fd()

[Rodrigo Campos]

There is a race when we clone: we call a function that just returns
while at the same time we try to get the userns via /proc/pid/ns/user.
The thing is that when the function returns, in the kernel do_exit()
from kernel/exit.c is called, which calls exit_task_namespaces() to destroy
the namespaces.

So, let's wait indefinitely there and add an _exit() call to avoid
warnings. We are already sending a SIGKILL to this pid, so nothing else
remaining to not leak the process.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 src/vfs/utils.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git src/vfs/utils.c src/vfs/utils.c
index ea7536c1..2331a3b7 100644
--- src/vfs/utils.c
+++ src/vfs/utils.c
@@ -60,7 +60,9 @@ pid_t do_clone(int (*fn)(void *), void *arg, int flags)
 
 static int get_userns_fd_cb(void *data)
 {
-	return 0;
+	for (;;)
+		pause();
+	_exit(0);
 }
 
 int wait_for_pid(pid_t pid)
-- 
2.39.2

Re: [PATCH v2 4/9] vfs: Fix race condition on get_userns_fd()

[Christian Brauner]

On Wed, Mar 08, 2023 at 12:13:38PM +0100, Rodrigo Campos wrote:
> There is a race when we clone: we call a function that just returns
> while at the same time we try to get the userns via /proc/pid/ns/user.
> The thing is that when the function returns, in the kernel do_exit()
> from kernel/exit.c is called, which calls exit_task_namespaces() to destroy
> the namespaces.
> 
> So, let's wait indefinitely there and add an _exit() call to avoid
> warnings. We are already sending a SIGKILL to this pid, so nothing else
> remaining to not leak the process.
> 
> Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> ---

Looks good,
Reviewed-by: Christian Brauner <brauner@kernel.org>

[PATCH v2 5/9] vfs: Make switch_userns set PR_SET_DUMPABLE

[Rodrigo Campos]

We need PR_SET_DUMPABLE in order to write the mapping files when
creating a userns. From prctl(2) PR_SET_DUMPABLE is reset when the
process's effective user or group ID is changed.

As we are changing the EUID here, we also reset it to allow creating
nested userns with subsequent switch_users() calls.

This was not causing any issues because we weren't using switch_users()
to create nested userns. Nested userns were created with
userns_fd_cb()/create_userns_hierarchy() that set PR_SET_DUMPABLE.

Future patches will rely on switch_users() to create nested userns. So
this patch fixes that.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Reviewed-by: Christian Brauner <brauner@kernel.org>
---
 src/vfs/utils.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git src/vfs/utils.c src/vfs/utils.c
index 2331a3b7..9e67ac37 100644
--- src/vfs/utils.c
+++ src/vfs/utils.c
@@ -286,6 +286,10 @@ bool switch_ids(uid_t uid, gid_t gid)
 	if (setresuid(uid, uid, uid))
 		return syserror("failure: setresuid");
 
+	/* Ensure we can access proc files from processes we can ptrace. */
+	if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0))
+		return syserror("failure: make dumpable");
+
 	return true;
 }
 
@@ -303,11 +307,6 @@ static int userns_fd_cb(void *data)
 	if (c == '1') {
 		if (!switch_ids(0, 0))
 			return syserror("failure: switch ids to 0");
-
-		/* Ensure we can access proc files from processes we can ptrace. */
-		ret = prctl(PR_SET_DUMPABLE, 1, 0, 0, 0);
-		if (ret < 0)
-			return syserror("failure: make dumpable");
 	}
 
 	ret = write_nointr(h->fd_event, "1", 1);
-- 
2.39.2

[PATCH v2 6/9] vfs: Prepare tests in &s_idmapped_mounts to be reused inside a userns

[Rodrigo Campos]

Future patches will call these tests within a userns. So, let's change
the makedev major/minor to something that works inside a userns.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 src/vfs/idmapped-mounts.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git src/vfs/idmapped-mounts.c src/vfs/idmapped-mounts.c
index ed7948b6..eb0df938 100644
--- src/vfs/idmapped-mounts.c
+++ src/vfs/idmapped-mounts.c
@@ -535,7 +535,7 @@ static int fsids_mapped(const struct vfstest_info *info)
 			die("failure: create");
 
 		/* create character device */
-		if (mknodat(open_tree_fd, CHRDEV1, S_IFCHR | 0644, makedev(5, 1)))
+		if (mknodat(open_tree_fd, CHRDEV1, S_IFCHR | 0644, makedev(0, 0)))
 			die("failure: create");
 
 		/* create symlink */
@@ -764,7 +764,7 @@ static int expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
 	}
 
 	/* create character device */
-	if (mknodat(info->t_dir1_fd, CHRDEV1, S_IFCHR | 0644, makedev(5, 1))) {
+	if (mknodat(info->t_dir1_fd, CHRDEV1, S_IFCHR | 0644, makedev(0, 0))) {
 		log_stderr("failure: mknodat");
 		goto out;
 	}
-- 
2.39.2

Re: [PATCH v2 6/9] vfs: Prepare tests in &s_idmapped_mounts to be reused inside a userns

[Christian Brauner]

On Wed, Mar 08, 2023 at 12:13:40PM +0100, Rodrigo Campos wrote:
> Future patches will call these tests within a userns. So, let's change
> the makedev major/minor to something that works inside a userns.
> 
> Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> ---

Looks good,
Reviewed-by: Christian Brauner <brauner@kernel.org>

[PATCH v2 7/9] vfs: Make idmapped core tests public

[Rodrigo Campos]

Tests on the suite s_idmapped_mounts are made public, future patches
for tmpfs will call them.

While making them public, we add a "tcore_" prefix so we don't make so
generic names public.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Reviewed-by: Christian Brauner <brauner@kernel.org>
---
 src/vfs/idmapped-mounts.c | 136 +++++++++++++++++++-------------------
 src/vfs/idmapped-mounts.h |  38 +++++++++++
 2 files changed, 106 insertions(+), 68 deletions(-)

diff --git src/vfs/idmapped-mounts.c src/vfs/idmapped-mounts.c
index eb0df938..547182fe 100644
--- src/vfs/idmapped-mounts.c
+++ src/vfs/idmapped-mounts.c
@@ -28,7 +28,7 @@
 
 static char t_buf[PATH_MAX];
 
-static int acls(const struct vfstest_info *info)
+int tcore_acls(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -254,7 +254,7 @@ out:
 }
 
 /* Validate that basic file operations on idmapped mounts from a user namespace. */
-static int create_in_userns(const struct vfstest_info *info)
+int tcore_create_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -372,7 +372,7 @@ out:
 /* Validate that a caller whose fsids map into the idmapped mount within it's
  * user namespace cannot create any device nodes.
  */
-static int device_node_in_userns(const struct vfstest_info *info)
+int tcore_device_node_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int open_tree_fd = -EBADF;
@@ -431,7 +431,7 @@ out:
 	return fret;
 }
 
-static int fsids_mapped(const struct vfstest_info *info)
+int tcore_fsids_mapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, hardlink_target_fd = -EBADF, open_tree_fd = -EBADF;
@@ -563,7 +563,7 @@ out:
 }
 
 /* Validate that basic file operations on idmapped mounts. */
-static int fsids_unmapped(const struct vfstest_info *info)
+int tcore_fsids_unmapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, hardlink_target_fd = -EBADF, open_tree_fd = -EBADF;
@@ -733,7 +733,7 @@ out:
 }
 
 /* Validate that changing file ownership works correctly on idmapped mounts. */
-static int expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
+int tcore_expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd1 = -EBADF, open_tree_fd2 = -EBADF;
@@ -1451,7 +1451,7 @@ out:
 	return fret;
 }
 
-static int fscaps_idmapped_mounts(const struct vfstest_info *info)
+int tcore_fscaps_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, file1_fd2 = -EBADF, open_tree_fd = -EBADF;
@@ -1599,7 +1599,7 @@ out:
 	return fret;
 }
 
-static int fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, file1_fd2 = -EBADF, open_tree_fd = -EBADF;
@@ -1812,7 +1812,7 @@ out:
 	return fret;
 }
 
-static int fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
+int tcore_fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, file1_fd2 = -EBADF, open_tree_fd = -EBADF;
@@ -1961,7 +1961,7 @@ out:
 	return fret;
 }
 
-static int hardlink_crossing_idmapped_mounts(const struct vfstest_info *info)
+int tcore_hardlink_crossing_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd1 = -EBADF, open_tree_fd2 = -EBADF;
@@ -2061,7 +2061,7 @@ out:
 	return fret;
 }
 
-static int hardlink_from_idmapped_mount(const struct vfstest_info *info)
+int tcore_hardlink_from_idmapped_mount(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2130,7 +2130,7 @@ out:
 	return fret;
 }
 
-static int hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info)
+int tcore_hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2207,7 +2207,7 @@ out:
 
 
 #ifdef HAVE_LIBURING_H
-static int io_uring_idmapped(const struct vfstest_info *info)
+int tcore_io_uring_idmapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2338,7 +2338,7 @@ out_unmap:
  * In no circumstances, even with recorded credentials can it be allowed to
  * open the file.
  */
-static int io_uring_idmapped_unmapped(const struct vfstest_info *info)
+int tcore_io_uring_idmapped_unmapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2453,7 +2453,7 @@ out_unmap:
 	return fret;
 }
 
-static int io_uring_idmapped_userns(const struct vfstest_info *info)
+int tcore_io_uring_idmapped_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2624,7 +2624,7 @@ out_unmap:
 	return fret;
 }
 
-static int io_uring_idmapped_unmapped_userns(const struct vfstest_info *info)
+int tcore_io_uring_idmapped_unmapped_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -2746,7 +2746,7 @@ out_unmap:
 #endif /* HAVE_LIBURING_H */
 
 /* Validate that protected symlinks work correctly on idmapped mounts. */
-static int protected_symlinks_idmapped_mounts(const struct vfstest_info *info)
+int tcore_protected_symlinks_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, fd = -EBADF, open_tree_fd = -EBADF;
@@ -2987,7 +2987,7 @@ out:
 /* Validate that protected symlinks work correctly on idmapped mounts inside a
  * user namespace.
  */
-static int protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, fd = -EBADF, open_tree_fd = -EBADF;
@@ -3234,7 +3234,7 @@ out:
 	return fret;
 }
 
-static int rename_crossing_idmapped_mounts(const struct vfstest_info *info)
+int tcore_rename_crossing_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd1 = -EBADF, open_tree_fd2 = -EBADF;
@@ -3332,7 +3332,7 @@ out:
 	return fret;
 }
 
-static int rename_from_idmapped_mount(const struct vfstest_info *info)
+int tcore_rename_from_idmapped_mount(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -3399,7 +3399,7 @@ out:
 	return fret;
 }
 
-static int rename_from_idmapped_mount_in_userns(const struct vfstest_info *info)
+int tcore_rename_from_idmapped_mount_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -3474,7 +3474,7 @@ out:
 	return fret;
 }
 
-static int setattr_truncate_idmapped(const struct vfstest_info *info)
+int tcore_setattr_truncate_idmapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -3588,7 +3588,7 @@ out:
 	return fret;
 }
 
-static int setattr_truncate_idmapped_in_userns(const struct vfstest_info *info)
+int tcore_setattr_truncate_idmapped_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -3780,7 +3780,7 @@ out:
 	return fret;
 }
 
-static int setgid_create_idmapped(const struct vfstest_info *info)
+int tcore_setgid_create_idmapped(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -3956,7 +3956,7 @@ out:
 	return fret;
 }
 
-static int setgid_create_idmapped_in_userns(const struct vfstest_info *info)
+int tcore_setgid_create_idmapped_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -4359,7 +4359,7 @@ out:
 }
 
 /* Validate that setid transitions are handled correctly on idmapped mounts. */
-static int setid_binaries_idmapped_mounts(const struct vfstest_info *info)
+int tcore_setid_binaries_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, exec_fd = -EBADF, open_tree_fd = -EBADF;
@@ -4498,7 +4498,7 @@ out:
  * running in a user namespace where the uid and gid of the setid binary have no
  * mapping.
  */
-static int setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, exec_fd = -EBADF, open_tree_fd = -EBADF;
@@ -4776,7 +4776,7 @@ out:
  * running in a user namespace where the uid and gid of the setid binary have no
  * mapping.
  */
-static int setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
+int tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, exec_fd = -EBADF, open_tree_fd = -EBADF;
@@ -5069,7 +5069,7 @@ out:
 	return fret;
 }
 
-static int sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info)
+int tcore_sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, open_tree_fd = -EBADF;
@@ -5362,7 +5362,7 @@ out:
 /* Validate that the sticky bit behaves correctly on idmapped mounts for unlink
  * operations in a user namespace.
  */
-static int sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, open_tree_fd = -EBADF;
@@ -5703,7 +5703,7 @@ out:
 	return fret;
 }
 
-static int sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info)
+int tcore_sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, open_tree_fd = -EBADF;
@@ -5960,7 +5960,7 @@ out:
 /* Validate that the sticky bit behaves correctly on idmapped mounts for unlink
  * operations in a user namespace.
  */
-static int sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int dir_fd = -EBADF, open_tree_fd = -EBADF;
@@ -6264,7 +6264,7 @@ out:
 	return fret;
 }
 
-static int symlink_idmapped_mounts(const struct vfstest_info *info)
+int tcore_symlink_idmapped_mounts(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -6349,7 +6349,7 @@ out:
 	return fret;
 }
 
-static int symlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
+int tcore_symlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
 {
 	int fret = -1;
 	int file1_fd = -EBADF, open_tree_fd = -EBADF;
@@ -8852,42 +8852,42 @@ out:
 }
 
 static const struct test_struct t_idmapped_mounts[] = {
-	{ acls,                                                         true,   "posix acls on regular mounts",                                                                 },
-	{ create_in_userns,                                             true,   "create operations in user namespace",                                                          },
-	{ device_node_in_userns,                                        true,   "device node in user namespace",                                                                },
-	{ expected_uid_gid_idmapped_mounts,				true,	"expected ownership on idmapped mounts",							},
-	{ fscaps_idmapped_mounts,					true,	"fscaps on idmapped mounts",									},
-	{ fscaps_idmapped_mounts_in_userns,				true,	"fscaps on idmapped mounts in user namespace",							},
-	{ fscaps_idmapped_mounts_in_userns_separate_userns,		true,	"fscaps on idmapped mounts in user namespace with different id mappings",			},
-	{ fsids_mapped,                                                 true,   "mapped fsids",                                                                                 },
-	{ fsids_unmapped,                                               true,   "unmapped fsids",                                                                               },
-	{ hardlink_crossing_idmapped_mounts,				true,	"cross idmapped mount hardlink",								},
-	{ hardlink_from_idmapped_mount,					true,	"hardlinks from idmapped mounts",								},
-	{ hardlink_from_idmapped_mount_in_userns,			true,	"hardlinks from idmapped mounts in user namespace",						},
+	{ tcore_acls,                                                         true,   "posix acls on regular mounts",                                                                 },
+	{ tcore_create_in_userns,                                             true,   "create operations in user namespace",                                                          },
+	{ tcore_device_node_in_userns,                                        true,   "device node in user namespace",                                                                },
+	{ tcore_expected_uid_gid_idmapped_mounts,				true,	"expected ownership on idmapped mounts",							},
+	{ tcore_fscaps_idmapped_mounts,					true,	"fscaps on idmapped mounts",									},
+	{ tcore_fscaps_idmapped_mounts_in_userns,				true,	"fscaps on idmapped mounts in user namespace",							},
+	{ tcore_fscaps_idmapped_mounts_in_userns_separate_userns,		true,	"fscaps on idmapped mounts in user namespace with different id mappings",			},
+	{ tcore_fsids_mapped,                                                 true,   "mapped fsids",                                                                                 },
+	{ tcore_fsids_unmapped,                                               true,   "unmapped fsids",                                                                               },
+	{ tcore_hardlink_crossing_idmapped_mounts,				true,	"cross idmapped mount hardlink",								},
+	{ tcore_hardlink_from_idmapped_mount,					true,	"hardlinks from idmapped mounts",								},
+	{ tcore_hardlink_from_idmapped_mount_in_userns,			true,	"hardlinks from idmapped mounts in user namespace",						},
 #ifdef HAVE_LIBURING_H
-	{ io_uring_idmapped,						true,	"io_uring from idmapped mounts",								},
-	{ io_uring_idmapped_userns,					true,	"io_uring from idmapped mounts in user namespace",						},
-	{ io_uring_idmapped_unmapped,					true,	"io_uring from idmapped mounts with unmapped ids",						},
-	{ io_uring_idmapped_unmapped_userns,				true,	"io_uring from idmapped mounts with unmapped ids in user namespace",				},
+	{ tcore_io_uring_idmapped,						true,	"io_uring from idmapped mounts",								},
+	{ tcore_io_uring_idmapped_userns,					true,	"io_uring from idmapped mounts in user namespace",						},
+	{ tcore_io_uring_idmapped_unmapped,					true,	"io_uring from idmapped mounts with unmapped ids",						},
+	{ tcore_io_uring_idmapped_unmapped_userns,				true,	"io_uring from idmapped mounts with unmapped ids in user namespace",				},
 #endif
-	{ protected_symlinks_idmapped_mounts,				true,	"following protected symlinks on idmapped mounts",						},
-	{ protected_symlinks_idmapped_mounts_in_userns,			true,	"following protected symlinks on idmapped mounts in user namespace",				},
-	{ rename_crossing_idmapped_mounts,				true,	"cross idmapped mount rename",									},
-	{ rename_from_idmapped_mount,					true,	"rename from idmapped mounts",									},
-	{ rename_from_idmapped_mount_in_userns,				true,	"rename from idmapped mounts in user namespace",						},
-	{ setattr_truncate_idmapped,					true,	"setattr truncate on idmapped mounts",								},
-	{ setattr_truncate_idmapped_in_userns,				true,	"setattr truncate on idmapped mounts in user namespace",					},
-	{ setgid_create_idmapped,					true,	"create operations in directories with setgid bit set on idmapped mounts",			},
-	{ setgid_create_idmapped_in_userns,				true,	"create operations in directories with setgid bit set on idmapped mounts in user namespace",	},
-	{ setid_binaries_idmapped_mounts,				true,	"setid binaries on idmapped mounts",								},
-	{ setid_binaries_idmapped_mounts_in_userns,			true,	"setid binaries on idmapped mounts in user namespace",						},
-	{ setid_binaries_idmapped_mounts_in_userns_separate_userns,	true,	"setid binaries on idmapped mounts in user namespace with different id mappings",		},
-	{ sticky_bit_unlink_idmapped_mounts,				true,	"sticky bit unlink operations on idmapped mounts",						},
-	{ sticky_bit_unlink_idmapped_mounts_in_userns,			true,	"sticky bit unlink operations on idmapped mounts in user namespace",				},
-	{ sticky_bit_rename_idmapped_mounts,				true,	"sticky bit rename operations on idmapped mounts",						},
-	{ sticky_bit_rename_idmapped_mounts_in_userns,			true,	"sticky bit rename operations on idmapped mounts in user namespace",				},
-	{ symlink_idmapped_mounts,					true,	"symlink from idmapped mounts",									},
-	{ symlink_idmapped_mounts_in_userns,				true,	"symlink from idmapped mounts in user namespace",						},
+	{ tcore_protected_symlinks_idmapped_mounts,				true,	"following protected symlinks on idmapped mounts",						},
+	{ tcore_protected_symlinks_idmapped_mounts_in_userns,			true,	"following protected symlinks on idmapped mounts in user namespace",				},
+	{ tcore_rename_crossing_idmapped_mounts,				true,	"cross idmapped mount rename",									},
+	{ tcore_rename_from_idmapped_mount,					true,	"rename from idmapped mounts",									},
+	{ tcore_rename_from_idmapped_mount_in_userns,				true,	"rename from idmapped mounts in user namespace",						},
+	{ tcore_setattr_truncate_idmapped,					true,	"setattr truncate on idmapped mounts",								},
+	{ tcore_setattr_truncate_idmapped_in_userns,				true,	"setattr truncate on idmapped mounts in user namespace",					},
+	{ tcore_setgid_create_idmapped,					true,	"create operations in directories with setgid bit set on idmapped mounts",			},
+	{ tcore_setgid_create_idmapped_in_userns,				true,	"create operations in directories with setgid bit set on idmapped mounts in user namespace",	},
+	{ tcore_setid_binaries_idmapped_mounts,				true,	"setid binaries on idmapped mounts",								},
+	{ tcore_setid_binaries_idmapped_mounts_in_userns,			true,	"setid binaries on idmapped mounts in user namespace",						},
+	{ tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns,	true,	"setid binaries on idmapped mounts in user namespace with different id mappings",		},
+	{ tcore_sticky_bit_unlink_idmapped_mounts,				true,	"sticky bit unlink operations on idmapped mounts",						},
+	{ tcore_sticky_bit_unlink_idmapped_mounts_in_userns,			true,	"sticky bit unlink operations on idmapped mounts in user namespace",				},
+	{ tcore_sticky_bit_rename_idmapped_mounts,				true,	"sticky bit rename operations on idmapped mounts",						},
+	{ tcore_sticky_bit_rename_idmapped_mounts_in_userns,			true,	"sticky bit rename operations on idmapped mounts in user namespace",				},
+	{ tcore_symlink_idmapped_mounts,					true,	"symlink from idmapped mounts",									},
+	{ tcore_symlink_idmapped_mounts_in_userns,				true,	"symlink from idmapped mounts in user namespace",						},
 };
 
 const struct test_suite s_idmapped_mounts = {
diff --git src/vfs/idmapped-mounts.h src/vfs/idmapped-mounts.h
index 3b0f0825..4a2c7b39 100644
--- src/vfs/idmapped-mounts.h
+++ src/vfs/idmapped-mounts.h
@@ -17,4 +17,42 @@ extern const struct test_suite s_setxattr_fix_705191b03d50;
 extern const struct test_suite s_setgid_create_umask_idmapped_mounts;
 extern const struct test_suite s_setgid_create_acl_idmapped_mounts;
 
+/* Core tests */
+int tcore_acls(const struct vfstest_info *info);
+int tcore_create_in_userns(const struct vfstest_info *info);
+int tcore_device_node_in_userns(const struct vfstest_info *info);
+int tcore_fsids_mapped(const struct vfstest_info *info);
+int tcore_fsids_unmapped(const struct vfstest_info *info);
+int tcore_expected_uid_gid_idmapped_mounts(const struct vfstest_info *info);
+int tcore_fscaps_idmapped_mounts(const struct vfstest_info *info);
+int tcore_fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info);
+int tcore_fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info);
+int tcore_hardlink_crossing_idmapped_mounts(const struct vfstest_info *info);
+int tcore_hardlink_from_idmapped_mount(const struct vfstest_info *info);
+int tcore_hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info);
+#ifdef HAVE_LIBURING_H
+int tcore_io_uring_idmapped(const struct vfstest_info *info);
+int tcore_io_uring_idmapped_userns(const struct vfstest_info *info);
+int tcore_io_uring_idmapped_unmapped(const struct vfstest_info *info);
+int tcore_io_uring_idmapped_unmapped_userns(const struct vfstest_info *info);
+#endif
+int tcore_protected_symlinks_idmapped_mounts(const struct vfstest_info *info);
+int tcore_protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info);
+int tcore_rename_crossing_idmapped_mounts(const struct vfstest_info *info);
+int tcore_rename_from_idmapped_mount(const struct vfstest_info *info);
+int tcore_rename_from_idmapped_mount_in_userns(const struct vfstest_info *info);
+int tcore_setattr_truncate_idmapped(const struct vfstest_info *info);
+int tcore_setattr_truncate_idmapped_in_userns(const struct vfstest_info *info);
+int tcore_setgid_create_idmapped(const struct vfstest_info *info);
+int tcore_setgid_create_idmapped_in_userns(const struct vfstest_info *info);
+int tcore_setid_binaries_idmapped_mounts(const struct vfstest_info *info);
+int tcore_setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info);
+int tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info);
+int tcore_sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info);
+int tcore_sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info);
+int tcore_sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info);
+int tcore_sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info);
+int tcore_symlink_idmapped_mounts(const struct vfstest_info *info);
+int tcore_symlink_idmapped_mounts_in_userns(const struct vfstest_info *info);
+
 #endif /* __IDMAPPED_MOUNTS_H */
-- 
2.39.2

[PATCH v2 8/9] vfs: Export test_setup() and test_cleanup()

[Rodrigo Campos]

Future patches will call existing test inside another test, so we need
to properly setup the test environment.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 src/vfs/vfstest.c |  4 ++--
 src/vfs/vfstest.h | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 src/vfs/vfstest.h

diff --git src/vfs/vfstest.c src/vfs/vfstest.c
index a840e007..325f04a1 100644
--- src/vfs/vfstest.c
+++ src/vfs/vfstest.c
@@ -80,7 +80,7 @@ static void stash_overflowgid(struct vfstest_info *info)
 	info->t_overflowgid = atoi(buf);
 }
 
-static void test_setup(struct vfstest_info *info)
+void test_setup(struct vfstest_info *info)
 {
 	if (mkdirat(info->t_mnt_fd, T_DIR1, 0777))
 		die("failure: mkdirat");
@@ -93,7 +93,7 @@ static void test_setup(struct vfstest_info *info)
 		die("failure: fchmod");
 }
 
-static void test_cleanup(struct vfstest_info *info)
+void test_cleanup(struct vfstest_info *info)
 {
 	safe_close(info->t_dir1_fd);
 	if (rm_r(info->t_mnt_fd, T_DIR1))
diff --git src/vfs/vfstest.h src/vfs/vfstest.h
new file mode 100644
index 00000000..6502d9f1
--- /dev/null
+++ src/vfs/vfstest.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __VFSTEST_H
+#define __VFSTEST_H
+
+void test_setup(struct vfstest_info *info);
+void test_cleanup(struct vfstest_info *info);
+
+
+#endif /* __VFSTEST_H */
-- 
2.39.2

Re: [PATCH v2 8/9] vfs: Export test_setup() and test_cleanup()

[Christian Brauner]

On Wed, Mar 08, 2023 at 12:13:42PM +0100, Rodrigo Campos wrote:
> Future patches will call existing test inside another test, so we need
> to properly setup the test environment.
> 
> Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> ---

Looks good,
Reviewed-by: Christian Brauner <brauner@kernel.org>

[PATCH v2 9/9] vfs: Add tmpfs tests for idmap mounts

[Rodrigo Campos]

This patch calls all tests in the suite s_idmapped_mounts, but with a
tmpfs directory mounted inside a userns. This directory is setup as the
mount point for the test that runs nested.

This excercises that tmpfs mounted inside a userns works as expected
regarding idmap mounts.

As some operations don't work inside a userns, we also set
info.t_inside_userns to true, so operations not supported are properly
skipped.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 src/vfs/Makefile                |   4 +-
 src/vfs/tmpfs-idmapped-mounts.c | 298 ++++++++++++++++++++++++++++++++
 src/vfs/tmpfs-idmapped-mounts.h |  15 ++
 src/vfs/utils.h                 |   2 +
 src/vfs/vfstest.c               |  13 +-
 tests/tmpfs/001                 |  27 +++
 tests/tmpfs/001.out             |   2 +
 tests/tmpfs/Makefile            |  24 +++
 8 files changed, 382 insertions(+), 3 deletions(-)
 create mode 100644 src/vfs/tmpfs-idmapped-mounts.c
 create mode 100644 src/vfs/tmpfs-idmapped-mounts.h
 create mode 100755 tests/tmpfs/001
 create mode 100644 tests/tmpfs/001.out
 create mode 100644 tests/tmpfs/Makefile

diff --git src/vfs/Makefile src/vfs/Makefile
index 1b0b364b..4841da12 100644
--- src/vfs/Makefile
+++ src/vfs/Makefile
@@ -4,10 +4,10 @@ TOPDIR = ../..
 include $(TOPDIR)/include/builddefs
 
 TARGETS = vfstest mount-idmapped
-CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c
+CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c tmpfs-idmapped-mounts.c
 CFILES_MOUNT_IDMAPPED = mount-idmapped.c utils.c
 
-HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h
+HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h tmpfs-idmapped-mounts.h
 LLDLIBS += -pthread
 LDIRT = $(TARGETS)
 
diff --git src/vfs/tmpfs-idmapped-mounts.c src/vfs/tmpfs-idmapped-mounts.c
new file mode 100644
index 00000000..2db1e879
--- /dev/null
+++ src/vfs/tmpfs-idmapped-mounts.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "../global.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <grp.h>
+#include <limits.h>
+#include <linux/limits.h>
+#include <linux/types.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <sys/fsuid.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/xattr.h>
+#include <unistd.h>
+
+#include "missing.h"
+#include "utils.h"
+#include "vfstest.h"
+#include "idmapped-mounts.h"
+
+static int tmpfs_nested_mount_setup(const struct vfstest_info *info, int (*test)(const struct vfstest_info *info))
+{
+	char path[PATH_MAX];
+	int fret = -1;
+
+	/* Create mapping for userns
+	 * Make the mapping quite long, so all nested userns that are created by
+	 * any test we call is contained here (otherwise userns creation fails).
+	 */
+	struct mount_attr attr = {
+		.attr_set	= MOUNT_ATTR_IDMAP,
+		.userns_fd	= -EBADF,
+	};
+	attr.userns_fd = get_userns_fd(0, 10000, 200000);
+	if (attr.userns_fd < 0) {
+		log_stderr("failure: get_userns_fd");
+		goto out_no_rm;
+	}
+
+	if (!switch_userns(attr.userns_fd, 0, 0, false)) {
+		log_stderr("failure: switch_userns");
+		goto out_no_rm;
+	}
+
+	/* create separate mount namespace */
+	if (unshare(CLONE_NEWNS)) {
+		log_stderr("failure: create new mount namespace");
+		goto out_no_rm;
+	}
+
+	/* Create DIR0 to mount there */
+	if (mkdirat(info->t_mnt_fd, DIR0, 0777)) {
+		log_stderr("failure: mkdirat");
+		goto out_no_rm;
+	}
+	if (fchmodat(info->t_mnt_fd, DIR0, 0777, 0)) {
+		log_stderr("failure: fchmodat");
+		goto out_no_umount;
+	}
+
+	snprintf(path, sizeof(path), "%s/%s", info->t_mountpoint, DIR0);
+	if (sys_mount("tmpfs", path, "tmpfs", 0, NULL)) {
+		log_stderr("failure: mount");
+		goto out_no_umount;
+	}
+
+	// Create a new info to use for test we will call.
+	struct vfstest_info nested_test_info = *info;
+	nested_test_info.t_mountpoint = strdup(path);
+	if (nested_test_info.t_mountpoint == NULL) {
+		log_stderr("failure: strdup");
+		goto out;
+	}
+	nested_test_info.t_mnt_fd = openat(-EBADF, nested_test_info.t_mountpoint, O_CLOEXEC | O_DIRECTORY);
+	if (nested_test_info.t_mnt_fd < 0) {
+		log_stderr("failure: openat");
+		goto out;
+	}
+
+	test_setup(&nested_test_info);
+
+	// Run the test.
+	if ((*test)(&nested_test_info)) {
+		log_stderr("failure: calling test");
+		goto out;
+	}
+
+	test_cleanup(&nested_test_info);
+
+	fret = 0;
+	log_debug("Ran test");
+out:
+	snprintf(path, sizeof(path), "%s/" DIR0, info->t_mountpoint);
+	sys_umount2(path, MNT_DETACH);
+out_no_umount:
+	if(rm_r(info->t_mnt_fd, DIR0))
+		log_stderr("failure: rm_r");
+out_no_rm:
+	safe_close(attr.userns_fd);
+	return fret;
+}
+
+static int tmpfs_acls(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_acls);
+}
+static int tmpfs_create_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_create_in_userns);
+}
+static int tmpfs_device_node_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_device_node_in_userns);
+}
+static int tmpfs_fsids_mapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_fsids_mapped);
+}
+static int tmpfs_fsids_unmapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_fsids_unmapped);
+}
+static int tmpfs_expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_expected_uid_gid_idmapped_mounts);
+}
+static int tmpfs_fscaps_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts);
+}
+static int tmpfs_fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns);
+}
+static int tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns_separate_userns);
+}
+
+static int tmpfs_hardlink_crossing_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_hardlink_crossing_idmapped_mounts);
+}
+static int tmpfs_hardlink_from_idmapped_mount(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount);
+}
+static int tmpfs_hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount_in_userns);
+}
+
+#ifdef HAVE_LIBURING_H
+static int tmpfs_io_uring_idmapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped);
+}
+static int tmpfs_io_uring_idmapped_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_userns);
+}
+static int tmpfs_io_uring_idmapped_unmapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped);
+}
+static int tmpfs_io_uring_idmapped_unmapped_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped_userns);
+}
+#endif /* HAVE_LIBURING_H */
+
+static int tmpfs_protected_symlinks_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts);
+}
+static int tmpfs_protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts_in_userns);
+}
+static int tmpfs_rename_crossing_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_rename_crossing_idmapped_mounts);
+}
+static int tmpfs_rename_from_idmapped_mount(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount);
+}
+static int tmpfs_rename_from_idmapped_mount_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount_in_userns);
+}
+static int tmpfs_setattr_truncate_idmapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped);
+}
+static int tmpfs_setattr_truncate_idmapped_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped_in_userns);
+}
+static int tmpfs_setgid_create_idmapped(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped);
+}
+static int tmpfs_setgid_create_idmapped_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped_in_userns);
+}
+static int tmpfs_setid_binaries_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts);
+}
+static int tmpfs_setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns);
+}
+static int tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns);
+}
+static int tmpfs_sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts);
+}
+static int tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts_in_userns);
+}
+static int tmpfs_sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts);
+}
+static int tmpfs_sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts_in_userns);
+}
+static int tmpfs_symlink_idmapped_mounts(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts);
+}
+static int tmpfs_symlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
+{
+	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts_in_userns);
+}
+
+static const struct test_struct t_tmpfs[] = {
+	{ tmpfs_acls,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
+	{ tmpfs_create_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
+	{ tmpfs_device_node_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs device node in user namespace",								      },
+	{ tmpfs_expected_uid_gid_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs expected ownership on idmapped mounts",							},
+	{ tmpfs_fscaps_idmapped_mounts,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts",									},
+	{ tmpfs_fscaps_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace",							},
+	{ tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns,		T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace with different id mappings",			},
+	{ tmpfs_fsids_mapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs mapped fsids",										      },
+	{ tmpfs_fsids_unmapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs unmapped fsids",										      },
+	{ tmpfs_hardlink_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount hardlink",								},
+	{ tmpfs_hardlink_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts",								},
+	{ tmpfs_hardlink_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts in user namespace",						},
+#ifdef HAVE_LIBURING_H
+	{ tmpfs_io_uring_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts",								      },
+	{ tmpfs_io_uring_idmapped_userns,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts in user namespace",					      },
+	{ tmpfs_io_uring_idmapped_unmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids",					      },
+	{ tmpfs_io_uring_idmapped_unmapped_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids in user namespace",			      },
+#endif
+	{ tmpfs_protected_symlinks_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts",						},
+	{ tmpfs_protected_symlinks_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts in user namespace",				},
+	{ tmpfs_rename_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount rename",									},
+	{ tmpfs_rename_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts",									},
+	{ tmpfs_rename_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts in user namespace",						},
+	{ tmpfs_setattr_truncate_idmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts",								},
+	{ tmpfs_setattr_truncate_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts in user namespace",					},
+	{ tmpfs_setgid_create_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts",			},
+	{ tmpfs_setgid_create_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts in user namespace",	},
+	{ tmpfs_setid_binaries_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts",								},
+	{ tmpfs_setid_binaries_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace",						},
+	{ tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns,	T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace with different id mappings",		},
+	{ tmpfs_sticky_bit_unlink_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts",						},
+	{ tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts in user namespace",				},
+	{ tmpfs_sticky_bit_rename_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts",						},
+	{ tmpfs_sticky_bit_rename_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts in user namespace",				},
+	{ tmpfs_symlink_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts",									},
+	{ tmpfs_symlink_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts in user namespace",						},
+};
+
+
+const struct test_suite s_tmpfs_idmapped_mounts = {
+	.tests = t_tmpfs,
+	.nr_tests = ARRAY_SIZE(t_tmpfs),
+};
diff --git src/vfs/tmpfs-idmapped-mounts.h src/vfs/tmpfs-idmapped-mounts.h
new file mode 100644
index 00000000..038d86a9
--- /dev/null
+++ src/vfs/tmpfs-idmapped-mounts.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __TMPFS_IDMAPPED_MOUNTS_H
+#define __TMPFS_IDMAPPED_MOUNTS_H
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "utils.h"
+
+extern const struct test_suite s_tmpfs_idmapped_mounts;
+
+#endif /* __TMPFS_IDMAPPED_MOUNTS_H */
+
diff --git src/vfs/utils.h src/vfs/utils.h
index f1681737..872fd96f 100644
--- src/vfs/utils.h
+++ src/vfs/utils.h
@@ -45,6 +45,8 @@
 #define DIR2 "dir2"
 #define DIR3 "dir3"
 #define DIR1_RENAME "dir1_rename"
+// This directory may be used by tests that call another test.
+#define DIR0 "dir0"
 #define HARDLINK1 "hardlink1"
 #define SYMLINK1 "symlink1"
 #define SYMLINK_USER1 "symlink_user1"
diff --git src/vfs/vfstest.c src/vfs/vfstest.c
index 325f04a1..f842117d 100644
--- src/vfs/vfstest.c
+++ src/vfs/vfstest.c
@@ -23,6 +23,7 @@
 #include <unistd.h>
 
 #include "btrfs-idmapped-mounts.h"
+#include "tmpfs-idmapped-mounts.h"
 #include "idmapped-mounts.h"
 #include "missing.h"
 #include "utils.h"
@@ -2316,6 +2317,7 @@ static void usage(void)
 	fprintf(stderr, "--test-fscaps-regression            Run fscap regression tests\n");
 	fprintf(stderr, "--test-nested-userns                Run nested userns idmapped mount testsuite\n");
 	fprintf(stderr, "--test-btrfs                        Run btrfs specific idmapped mount testsuite\n");
+	fprintf(stderr, "--test-tmpfs                        Run tmpfs specific idmapped mount testsuite\n");
 	fprintf(stderr, "--test-setattr-fix-968219708108     Run setattr regression tests\n");
 	fprintf(stderr, "--test-setxattr-fix-705191b03d50    Run setxattr regression tests\n");
 	fprintf(stderr, "--test-setgid-create-umask          Run setgid with umask tests\n");
@@ -2340,6 +2342,7 @@ static const struct option longopts[] = {
 	{"test-setxattr-fix-705191b03d50",	no_argument,		0,	'j'},
 	{"test-setgid-create-umask",		no_argument,		0,	'u'},
 	{"test-setgid-create-acl",		no_argument,		0,	'l'},
+	{"test-tmpfs",				no_argument,		0,	't'},
 	{NULL,					0,			0,	  0},
 };
 
@@ -2480,7 +2483,7 @@ int main(int argc, char *argv[])
 	bool idmapped_mounts_supported = false, test_btrfs = false,
 	     test_core = false, test_fscaps_regression = false,
 	     test_nested_userns = false, test_setattr_fix_968219708108 = false,
-	     test_setxattr_fix_705191b03d50 = false,
+	     test_setxattr_fix_705191b03d50 = false, test_tmpfs = false,
 	     test_setgid_create_umask = false, test_setgid_create_acl = false;
 
 	init_vfstest_info(&info);
@@ -2529,6 +2532,9 @@ int main(int argc, char *argv[])
 		case 'l':
 			test_setgid_create_acl = true;
 			break;
+		case 't':
+			test_tmpfs = true;
+			break;
 		case 'h':
 			/* fallthrough */
 		default:
@@ -2622,6 +2628,11 @@ int main(int argc, char *argv[])
 			goto out;
 	}
 
+	if (test_tmpfs) {
+		if (!run_suite(&info, &s_tmpfs_idmapped_mounts))
+			goto out;
+	}
+
 	fret = EXIT_SUCCESS;
 
 out:
diff --git tests/tmpfs/001 tests/tmpfs/001
new file mode 100755
index 00000000..37f5439e
--- /dev/null
+++ tests/tmpfs/001
@@ -0,0 +1,27 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 Rodrigo Campos Catelin.  All Rights Reserved.
+#
+# FS QA Test 001
+#
+# Test that idmapped mounts behave correctly with tmpfs filesystem.
+#
+. ./common/preamble
+_begin_fstest auto quick idmapped
+
+# get standard environment, filters and checks
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs tmpfs
+_require_idmapped_mounts
+_require_test
+
+echo "Silence is golden"
+
+$here/src/vfs/vfstest --test-tmpfs --device "$TEST_DEV" \
+	        --mount "$TEST_DIR" --fstype "$FSTYP"
+
+status=$?
+exit
diff --git tests/tmpfs/001.out tests/tmpfs/001.out
new file mode 100644
index 00000000..88678b8e
--- /dev/null
+++ tests/tmpfs/001.out
@@ -0,0 +1,2 @@
+QA output created by 001
+Silence is golden
diff --git tests/tmpfs/Makefile tests/tmpfs/Makefile
new file mode 100644
index 00000000..b464b22b
--- /dev/null
+++ tests/tmpfs/Makefile
@@ -0,0 +1,24 @@
+#
+# Copyright (c) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
+#
+
+TOPDIR = ../..
+include $(TOPDIR)/include/builddefs
+include $(TOPDIR)/include/buildgrouplist
+
+GENERIC_DIR = generic
+TARGET_DIR = $(PKG_LIB_DIR)/$(TESTS_DIR)/$(GENERIC_DIR)
+DIRT = group.list
+
+default: $(DIRT)
+
+include $(BUILDRULES)
+
+install:
+	$(INSTALL) -m 755 -d $(TARGET_DIR)
+	$(INSTALL) -m 755 $(TESTS) $(TARGET_DIR)
+	$(INSTALL) -m 644 group.list $(TARGET_DIR)
+	$(INSTALL) -m 644 $(OUTFILES) $(TARGET_DIR)
+
+# Nothing.
+install-dev install-lib:
-- 
2.39.2

Re: [PATCH v2 9/9] vfs: Add tmpfs tests for idmap mounts

[Christian Brauner]

On Wed, Mar 08, 2023 at 12:13:43PM +0100, Rodrigo Campos wrote:
> This patch calls all tests in the suite s_idmapped_mounts, but with a
> tmpfs directory mounted inside a userns. This directory is setup as the
> mount point for the test that runs nested.
> 
> This excercises that tmpfs mounted inside a userns works as expected
> regarding idmap mounts.
> 
> As some operations don't work inside a userns, we also set
> info.t_inside_userns to true, so operations not supported are properly
> skipped.

I don't think t_inside_userns is used anymore so this can just be
dropped from the commit message. Though I'm not sure whether you need to
resend this or whether Zorro would be fine with just dropping it when he
applies the patches.

A few minor comments below.

> 
> Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> ---
>  src/vfs/Makefile                |   4 +-
>  src/vfs/tmpfs-idmapped-mounts.c | 298 ++++++++++++++++++++++++++++++++
>  src/vfs/tmpfs-idmapped-mounts.h |  15 ++
>  src/vfs/utils.h                 |   2 +
>  src/vfs/vfstest.c               |  13 +-
>  tests/tmpfs/001                 |  27 +++
>  tests/tmpfs/001.out             |   2 +
>  tests/tmpfs/Makefile            |  24 +++
>  8 files changed, 382 insertions(+), 3 deletions(-)
>  create mode 100644 src/vfs/tmpfs-idmapped-mounts.c
>  create mode 100644 src/vfs/tmpfs-idmapped-mounts.h
>  create mode 100755 tests/tmpfs/001
>  create mode 100644 tests/tmpfs/001.out
>  create mode 100644 tests/tmpfs/Makefile
> 
> diff --git src/vfs/Makefile src/vfs/Makefile
> index 1b0b364b..4841da12 100644
> --- src/vfs/Makefile
> +++ src/vfs/Makefile
> @@ -4,10 +4,10 @@ TOPDIR = ../..
>  include $(TOPDIR)/include/builddefs
>  
>  TARGETS = vfstest mount-idmapped
> -CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c
> +CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c tmpfs-idmapped-mounts.c
>  CFILES_MOUNT_IDMAPPED = mount-idmapped.c utils.c
>  
> -HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h
> +HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h tmpfs-idmapped-mounts.h
>  LLDLIBS += -pthread
>  LDIRT = $(TARGETS)
>  
> diff --git src/vfs/tmpfs-idmapped-mounts.c src/vfs/tmpfs-idmapped-mounts.c
> new file mode 100644
> index 00000000..2db1e879
> --- /dev/null
> +++ src/vfs/tmpfs-idmapped-mounts.c
> @@ -0,0 +1,298 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#ifndef _GNU_SOURCE
> +#define _GNU_SOURCE
> +#endif
> +
> +#include "../global.h"
> +
> +#include <dirent.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <getopt.h>
> +#include <grp.h>
> +#include <limits.h>
> +#include <linux/limits.h>
> +#include <linux/types.h>
> +#include <pthread.h>
> +#include <pwd.h>
> +#include <sched.h>
> +#include <stdbool.h>
> +#include <sys/fsuid.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <sys/xattr.h>
> +#include <unistd.h>
> +
> +#include "missing.h"
> +#include "utils.h"
> +#include "vfstest.h"
> +#include "idmapped-mounts.h"
> +
> +static int tmpfs_nested_mount_setup(const struct vfstest_info *info, int (*test)(const struct vfstest_info *info))
> +{
> +	char path[PATH_MAX];
> +	int fret = -1;
> +
> +	/* Create mapping for userns
> +	 * Make the mapping quite long, so all nested userns that are created by
> +	 * any test we call is contained here (otherwise userns creation fails).
> +	 */
> +	struct mount_attr attr = {
> +		.attr_set	= MOUNT_ATTR_IDMAP,
> +		.userns_fd	= -EBADF,
> +	};
> +	attr.userns_fd = get_userns_fd(0, 10000, 200000);
> +	if (attr.userns_fd < 0) {
> +		log_stderr("failure: get_userns_fd");
> +		goto out_no_rm;
> +	}
> +
> +	if (!switch_userns(attr.userns_fd, 0, 0, false)) {
> +		log_stderr("failure: switch_userns");
> +		goto out_no_rm;
> +	}
> +
> +	/* create separate mount namespace */
> +	if (unshare(CLONE_NEWNS)) {
> +		log_stderr("failure: create new mount namespace");
> +		goto out_no_rm;
> +	}

I think you might want to turn off mount propagation here so that the
tmpfs mount doesn't propagate into the parent mount namespace:

	mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0)

> +
> +	/* Create DIR0 to mount there */
> +	if (mkdirat(info->t_mnt_fd, DIR0, 0777)) {
> +		log_stderr("failure: mkdirat");
> +		goto out_no_rm;
> +	}
> +	if (fchmodat(info->t_mnt_fd, DIR0, 0777, 0)) {
> +		log_stderr("failure: fchmodat");
> +		goto out_no_umount;
> +	}
> +
> +	snprintf(path, sizeof(path), "%s/%s", info->t_mountpoint, DIR0);
> +	if (sys_mount("tmpfs", path, "tmpfs", 0, NULL)) {
> +		log_stderr("failure: mount");
> +		goto out_no_umount;
> +	}
> +
> +	// Create a new info to use for test we will call.
> +	struct vfstest_info nested_test_info = *info;

nit: We usually don't mix declarations and code in C code so I would
move that struct vfstest_info to the top of the function.

> +	nested_test_info.t_mountpoint = strdup(path);
> +	if (nested_test_info.t_mountpoint == NULL) {

nit: more idiomatic  
if (!nested_test_info.t_mountpoint)

> +		log_stderr("failure: strdup");
> +		goto out;
> +	}
> +	nested_test_info.t_mnt_fd = openat(-EBADF, nested_test_info.t_mountpoint, O_CLOEXEC | O_DIRECTORY);
> +	if (nested_test_info.t_mnt_fd < 0) {
> +		log_stderr("failure: openat");
> +		goto out;
> +	}
> +
> +	test_setup(&nested_test_info);
> +
> +	// Run the test.
> +	if ((*test)(&nested_test_info)) {
> +		log_stderr("failure: calling test");
> +		goto out;
> +	}
> +
> +	test_cleanup(&nested_test_info);
> +
> +	fret = 0;
> +	log_debug("Ran test");
> +out:
> +	snprintf(path, sizeof(path), "%s/" DIR0, info->t_mountpoint);
> +	sys_umount2(path, MNT_DETACH);
> +out_no_umount:
> +	if(rm_r(info->t_mnt_fd, DIR0))

nit: missing space between "if" and "("

> +		log_stderr("failure: rm_r");
> +out_no_rm:
> +	safe_close(attr.userns_fd);
> +	return fret;
> +}
> +
> +static int tmpfs_acls(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_acls);
> +}
> +static int tmpfs_create_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_create_in_userns);
> +}
> +static int tmpfs_device_node_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_device_node_in_userns);
> +}
> +static int tmpfs_fsids_mapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_fsids_mapped);
> +}
> +static int tmpfs_fsids_unmapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_fsids_unmapped);
> +}
> +static int tmpfs_expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_expected_uid_gid_idmapped_mounts);
> +}
> +static int tmpfs_fscaps_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts);
> +}
> +static int tmpfs_fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns);
> +}
> +static int tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns_separate_userns);
> +}
> +
> +static int tmpfs_hardlink_crossing_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_hardlink_crossing_idmapped_mounts);
> +}
> +static int tmpfs_hardlink_from_idmapped_mount(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount);
> +}
> +static int tmpfs_hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount_in_userns);
> +}
> +
> +#ifdef HAVE_LIBURING_H
> +static int tmpfs_io_uring_idmapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped);
> +}
> +static int tmpfs_io_uring_idmapped_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_userns);
> +}
> +static int tmpfs_io_uring_idmapped_unmapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped);
> +}
> +static int tmpfs_io_uring_idmapped_unmapped_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped_userns);
> +}
> +#endif /* HAVE_LIBURING_H */
> +
> +static int tmpfs_protected_symlinks_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts);
> +}
> +static int tmpfs_protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts_in_userns);
> +}
> +static int tmpfs_rename_crossing_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_rename_crossing_idmapped_mounts);
> +}
> +static int tmpfs_rename_from_idmapped_mount(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount);
> +}
> +static int tmpfs_rename_from_idmapped_mount_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount_in_userns);
> +}
> +static int tmpfs_setattr_truncate_idmapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped);
> +}
> +static int tmpfs_setattr_truncate_idmapped_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped_in_userns);
> +}
> +static int tmpfs_setgid_create_idmapped(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped);
> +}
> +static int tmpfs_setgid_create_idmapped_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped_in_userns);
> +}
> +static int tmpfs_setid_binaries_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts);
> +}
> +static int tmpfs_setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns);
> +}
> +static int tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns);
> +}
> +static int tmpfs_sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts);
> +}
> +static int tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts_in_userns);
> +}
> +static int tmpfs_sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts);
> +}
> +static int tmpfs_sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts_in_userns);
> +}
> +static int tmpfs_symlink_idmapped_mounts(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts);
> +}
> +static int tmpfs_symlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
> +{
> +	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts_in_userns);
> +}
> +
> +static const struct test_struct t_tmpfs[] = {
> +	{ tmpfs_acls,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
> +	{ tmpfs_create_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
> +	{ tmpfs_device_node_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs device node in user namespace",								      },
> +	{ tmpfs_expected_uid_gid_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs expected ownership on idmapped mounts",							},
> +	{ tmpfs_fscaps_idmapped_mounts,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts",									},
> +	{ tmpfs_fscaps_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace",							},
> +	{ tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns,		T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace with different id mappings",			},
> +	{ tmpfs_fsids_mapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs mapped fsids",										      },
> +	{ tmpfs_fsids_unmapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs unmapped fsids",										      },
> +	{ tmpfs_hardlink_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount hardlink",								},
> +	{ tmpfs_hardlink_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts",								},
> +	{ tmpfs_hardlink_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts in user namespace",						},
> +#ifdef HAVE_LIBURING_H
> +	{ tmpfs_io_uring_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts",								      },
> +	{ tmpfs_io_uring_idmapped_userns,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts in user namespace",					      },
> +	{ tmpfs_io_uring_idmapped_unmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids",					      },
> +	{ tmpfs_io_uring_idmapped_unmapped_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids in user namespace",			      },
> +#endif
> +	{ tmpfs_protected_symlinks_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts",						},
> +	{ tmpfs_protected_symlinks_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts in user namespace",				},
> +	{ tmpfs_rename_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount rename",									},
> +	{ tmpfs_rename_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts",									},
> +	{ tmpfs_rename_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts in user namespace",						},
> +	{ tmpfs_setattr_truncate_idmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts",								},
> +	{ tmpfs_setattr_truncate_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts in user namespace",					},
> +	{ tmpfs_setgid_create_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts",			},
> +	{ tmpfs_setgid_create_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts in user namespace",	},
> +	{ tmpfs_setid_binaries_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts",								},
> +	{ tmpfs_setid_binaries_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace",						},
> +	{ tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns,	T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace with different id mappings",		},
> +	{ tmpfs_sticky_bit_unlink_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts",						},
> +	{ tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts in user namespace",				},
> +	{ tmpfs_sticky_bit_rename_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts",						},
> +	{ tmpfs_sticky_bit_rename_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts in user namespace",				},
> +	{ tmpfs_symlink_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts",									},
> +	{ tmpfs_symlink_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts in user namespace",						},
> +};
> +
> +
> +const struct test_suite s_tmpfs_idmapped_mounts = {
> +	.tests = t_tmpfs,
> +	.nr_tests = ARRAY_SIZE(t_tmpfs),
> +};
> diff --git src/vfs/tmpfs-idmapped-mounts.h src/vfs/tmpfs-idmapped-mounts.h
> new file mode 100644
> index 00000000..038d86a9
> --- /dev/null
> +++ src/vfs/tmpfs-idmapped-mounts.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __TMPFS_IDMAPPED_MOUNTS_H
> +#define __TMPFS_IDMAPPED_MOUNTS_H
> +
> +#ifndef _GNU_SOURCE
> +#define _GNU_SOURCE
> +#endif
> +
> +#include "utils.h"
> +
> +extern const struct test_suite s_tmpfs_idmapped_mounts;
> +
> +#endif /* __TMPFS_IDMAPPED_MOUNTS_H */
> +
> diff --git src/vfs/utils.h src/vfs/utils.h
> index f1681737..872fd96f 100644
> --- src/vfs/utils.h
> +++ src/vfs/utils.h
> @@ -45,6 +45,8 @@
>  #define DIR2 "dir2"
>  #define DIR3 "dir3"
>  #define DIR1_RENAME "dir1_rename"
> +// This directory may be used by tests that call another test.
> +#define DIR0 "dir0"
>  #define HARDLINK1 "hardlink1"
>  #define SYMLINK1 "symlink1"
>  #define SYMLINK_USER1 "symlink_user1"
> diff --git src/vfs/vfstest.c src/vfs/vfstest.c
> index 325f04a1..f842117d 100644
> --- src/vfs/vfstest.c
> +++ src/vfs/vfstest.c
> @@ -23,6 +23,7 @@
>  #include <unistd.h>
>  
>  #include "btrfs-idmapped-mounts.h"
> +#include "tmpfs-idmapped-mounts.h"
>  #include "idmapped-mounts.h"
>  #include "missing.h"
>  #include "utils.h"
> @@ -2316,6 +2317,7 @@ static void usage(void)
>  	fprintf(stderr, "--test-fscaps-regression            Run fscap regression tests\n");
>  	fprintf(stderr, "--test-nested-userns                Run nested userns idmapped mount testsuite\n");
>  	fprintf(stderr, "--test-btrfs                        Run btrfs specific idmapped mount testsuite\n");
> +	fprintf(stderr, "--test-tmpfs                        Run tmpfs specific idmapped mount testsuite\n");
>  	fprintf(stderr, "--test-setattr-fix-968219708108     Run setattr regression tests\n");
>  	fprintf(stderr, "--test-setxattr-fix-705191b03d50    Run setxattr regression tests\n");
>  	fprintf(stderr, "--test-setgid-create-umask          Run setgid with umask tests\n");
> @@ -2340,6 +2342,7 @@ static const struct option longopts[] = {
>  	{"test-setxattr-fix-705191b03d50",	no_argument,		0,	'j'},
>  	{"test-setgid-create-umask",		no_argument,		0,	'u'},
>  	{"test-setgid-create-acl",		no_argument,		0,	'l'},
> +	{"test-tmpfs",				no_argument,		0,	't'},
>  	{NULL,					0,			0,	  0},
>  };
>  
> @@ -2480,7 +2483,7 @@ int main(int argc, char *argv[])
>  	bool idmapped_mounts_supported = false, test_btrfs = false,
>  	     test_core = false, test_fscaps_regression = false,
>  	     test_nested_userns = false, test_setattr_fix_968219708108 = false,
> -	     test_setxattr_fix_705191b03d50 = false,
> +	     test_setxattr_fix_705191b03d50 = false, test_tmpfs = false,
>  	     test_setgid_create_umask = false, test_setgid_create_acl = false;
>  
>  	init_vfstest_info(&info);
> @@ -2529,6 +2532,9 @@ int main(int argc, char *argv[])
>  		case 'l':
>  			test_setgid_create_acl = true;
>  			break;
> +		case 't':
> +			test_tmpfs = true;
> +			break;
>  		case 'h':
>  			/* fallthrough */
>  		default:
> @@ -2622,6 +2628,11 @@ int main(int argc, char *argv[])
>  			goto out;
>  	}
>  
> +	if (test_tmpfs) {
> +		if (!run_suite(&info, &s_tmpfs_idmapped_mounts))
> +			goto out;
> +	}
> +
>  	fret = EXIT_SUCCESS;
>  
>  out:
> diff --git tests/tmpfs/001 tests/tmpfs/001
> new file mode 100755
> index 00000000..37f5439e
> --- /dev/null
> +++ tests/tmpfs/001
> @@ -0,0 +1,27 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2023 Rodrigo Campos Catelin.  All Rights Reserved.
> +#
> +# FS QA Test 001
> +#
> +# Test that idmapped mounts behave correctly with tmpfs filesystem.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick idmapped
> +
> +# get standard environment, filters and checks
> +. ./common/filter
> +
> +# real QA test starts here
> +
> +_supported_fs tmpfs
> +_require_idmapped_mounts
> +_require_test
> +
> +echo "Silence is golden"
> +
> +$here/src/vfs/vfstest --test-tmpfs --device "$TEST_DEV" \
> +	        --mount "$TEST_DIR" --fstype "$FSTYP"
> +
> +status=$?
> +exit
> diff --git tests/tmpfs/001.out tests/tmpfs/001.out
> new file mode 100644
> index 00000000..88678b8e
> --- /dev/null
> +++ tests/tmpfs/001.out
> @@ -0,0 +1,2 @@
> +QA output created by 001
> +Silence is golden
> diff --git tests/tmpfs/Makefile tests/tmpfs/Makefile
> new file mode 100644
> index 00000000..b464b22b
> --- /dev/null
> +++ tests/tmpfs/Makefile
> @@ -0,0 +1,24 @@
> +#
> +# Copyright (c) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
> +#
> +
> +TOPDIR = ../..
> +include $(TOPDIR)/include/builddefs
> +include $(TOPDIR)/include/buildgrouplist
> +
> +GENERIC_DIR = generic
> +TARGET_DIR = $(PKG_LIB_DIR)/$(TESTS_DIR)/$(GENERIC_DIR)
> +DIRT = group.list
> +
> +default: $(DIRT)
> +
> +include $(BUILDRULES)
> +
> +install:
> +	$(INSTALL) -m 755 -d $(TARGET_DIR)
> +	$(INSTALL) -m 755 $(TESTS) $(TARGET_DIR)
> +	$(INSTALL) -m 644 group.list $(TARGET_DIR)
> +	$(INSTALL) -m 644 $(OUTFILES) $(TARGET_DIR)
> +
> +# Nothing.
> +install-dev install-lib:
> -- 
> 2.39.2
> 

Re: [PATCH v2 9/9] vfs: Add tmpfs tests for idmap mounts

[Zorro Lang]

On Mon, Mar 13, 2023 at 11:50:18AM +0100, Christian Brauner wrote:
> On Wed, Mar 08, 2023 at 12:13:43PM +0100, Rodrigo Campos wrote:
> > This patch calls all tests in the suite s_idmapped_mounts, but with a
> > tmpfs directory mounted inside a userns. This directory is setup as the
> > mount point for the test that runs nested.
> > 
> > This excercises that tmpfs mounted inside a userns works as expected
> > regarding idmap mounts.
> > 
> > As some operations don't work inside a userns, we also set
> > info.t_inside_userns to true, so operations not supported are properly
> > skipped.
> 
> I don't think t_inside_userns is used anymore so this can just be
> dropped from the commit message. Though I'm not sure whether you need to
> resend this or whether Zorro would be fine with just dropping it when he
> applies the patches.

I can help to do this change, but ...

> 
> A few minor comments below.

... as you have more review points below, and need to change more things. To
avoid misunderstanding, it would be better to let the author do the change,
refer to you review points.

Thanks,
Zorro

> 
> > 
> > Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
> > ---
> >  src/vfs/Makefile                |   4 +-
> >  src/vfs/tmpfs-idmapped-mounts.c | 298 ++++++++++++++++++++++++++++++++
> >  src/vfs/tmpfs-idmapped-mounts.h |  15 ++
> >  src/vfs/utils.h                 |   2 +
> >  src/vfs/vfstest.c               |  13 +-
> >  tests/tmpfs/001                 |  27 +++
> >  tests/tmpfs/001.out             |   2 +
> >  tests/tmpfs/Makefile            |  24 +++
> >  8 files changed, 382 insertions(+), 3 deletions(-)
> >  create mode 100644 src/vfs/tmpfs-idmapped-mounts.c
> >  create mode 100644 src/vfs/tmpfs-idmapped-mounts.h
> >  create mode 100755 tests/tmpfs/001
> >  create mode 100644 tests/tmpfs/001.out
> >  create mode 100644 tests/tmpfs/Makefile
> > 
> > diff --git src/vfs/Makefile src/vfs/Makefile
> > index 1b0b364b..4841da12 100644
> > --- src/vfs/Makefile
> > +++ src/vfs/Makefile
> > @@ -4,10 +4,10 @@ TOPDIR = ../..
> >  include $(TOPDIR)/include/builddefs
> >  
> >  TARGETS = vfstest mount-idmapped
> > -CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c
> > +CFILES_VFSTEST = vfstest.c btrfs-idmapped-mounts.c idmapped-mounts.c utils.c tmpfs-idmapped-mounts.c
> >  CFILES_MOUNT_IDMAPPED = mount-idmapped.c utils.c
> >  
> > -HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h
> > +HFILES = missing.h utils.h btrfs-idmapped-mounts.h idmapped-mounts.h tmpfs-idmapped-mounts.h
> >  LLDLIBS += -pthread
> >  LDIRT = $(TARGETS)
> >  
> > diff --git src/vfs/tmpfs-idmapped-mounts.c src/vfs/tmpfs-idmapped-mounts.c
> > new file mode 100644
> > index 00000000..2db1e879
> > --- /dev/null
> > +++ src/vfs/tmpfs-idmapped-mounts.c
> > @@ -0,0 +1,298 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#ifndef _GNU_SOURCE
> > +#define _GNU_SOURCE
> > +#endif
> > +
> > +#include "../global.h"
> > +
> > +#include <dirent.h>
> > +#include <errno.h>
> > +#include <fcntl.h>
> > +#include <getopt.h>
> > +#include <grp.h>
> > +#include <limits.h>
> > +#include <linux/limits.h>
> > +#include <linux/types.h>
> > +#include <pthread.h>
> > +#include <pwd.h>
> > +#include <sched.h>
> > +#include <stdbool.h>
> > +#include <sys/fsuid.h>
> > +#include <sys/stat.h>
> > +#include <sys/types.h>
> > +#include <sys/xattr.h>
> > +#include <unistd.h>
> > +
> > +#include "missing.h"
> > +#include "utils.h"
> > +#include "vfstest.h"
> > +#include "idmapped-mounts.h"
> > +
> > +static int tmpfs_nested_mount_setup(const struct vfstest_info *info, int (*test)(const struct vfstest_info *info))
> > +{
> > +	char path[PATH_MAX];
> > +	int fret = -1;
> > +
> > +	/* Create mapping for userns
> > +	 * Make the mapping quite long, so all nested userns that are created by
> > +	 * any test we call is contained here (otherwise userns creation fails).
> > +	 */
> > +	struct mount_attr attr = {
> > +		.attr_set	= MOUNT_ATTR_IDMAP,
> > +		.userns_fd	= -EBADF,
> > +	};
> > +	attr.userns_fd = get_userns_fd(0, 10000, 200000);
> > +	if (attr.userns_fd < 0) {
> > +		log_stderr("failure: get_userns_fd");
> > +		goto out_no_rm;
> > +	}
> > +
> > +	if (!switch_userns(attr.userns_fd, 0, 0, false)) {
> > +		log_stderr("failure: switch_userns");
> > +		goto out_no_rm;
> > +	}
> > +
> > +	/* create separate mount namespace */
> > +	if (unshare(CLONE_NEWNS)) {
> > +		log_stderr("failure: create new mount namespace");
> > +		goto out_no_rm;
> > +	}
> 
> I think you might want to turn off mount propagation here so that the
> tmpfs mount doesn't propagate into the parent mount namespace:
> 
> 	mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0)
> 
> > +
> > +	/* Create DIR0 to mount there */
> > +	if (mkdirat(info->t_mnt_fd, DIR0, 0777)) {
> > +		log_stderr("failure: mkdirat");
> > +		goto out_no_rm;
> > +	}
> > +	if (fchmodat(info->t_mnt_fd, DIR0, 0777, 0)) {
> > +		log_stderr("failure: fchmodat");
> > +		goto out_no_umount;
> > +	}
> > +
> > +	snprintf(path, sizeof(path), "%s/%s", info->t_mountpoint, DIR0);
> > +	if (sys_mount("tmpfs", path, "tmpfs", 0, NULL)) {
> > +		log_stderr("failure: mount");
> > +		goto out_no_umount;
> > +	}
> > +
> > +	// Create a new info to use for test we will call.
> > +	struct vfstest_info nested_test_info = *info;
> 
> nit: We usually don't mix declarations and code in C code so I would
> move that struct vfstest_info to the top of the function.
> 
> > +	nested_test_info.t_mountpoint = strdup(path);
> > +	if (nested_test_info.t_mountpoint == NULL) {
> 
> nit: more idiomatic  
> if (!nested_test_info.t_mountpoint)
> 
> > +		log_stderr("failure: strdup");
> > +		goto out;
> > +	}
> > +	nested_test_info.t_mnt_fd = openat(-EBADF, nested_test_info.t_mountpoint, O_CLOEXEC | O_DIRECTORY);
> > +	if (nested_test_info.t_mnt_fd < 0) {
> > +		log_stderr("failure: openat");
> > +		goto out;
> > +	}
> > +
> > +	test_setup(&nested_test_info);
> > +
> > +	// Run the test.
> > +	if ((*test)(&nested_test_info)) {
> > +		log_stderr("failure: calling test");
> > +		goto out;
> > +	}
> > +
> > +	test_cleanup(&nested_test_info);
> > +
> > +	fret = 0;
> > +	log_debug("Ran test");
> > +out:
> > +	snprintf(path, sizeof(path), "%s/" DIR0, info->t_mountpoint);
> > +	sys_umount2(path, MNT_DETACH);
> > +out_no_umount:
> > +	if(rm_r(info->t_mnt_fd, DIR0))
> 
> nit: missing space between "if" and "("
> 
> > +		log_stderr("failure: rm_r");
> > +out_no_rm:
> > +	safe_close(attr.userns_fd);
> > +	return fret;
> > +}
> > +
> > +static int tmpfs_acls(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_acls);
> > +}
> > +static int tmpfs_create_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_create_in_userns);
> > +}
> > +static int tmpfs_device_node_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_device_node_in_userns);
> > +}
> > +static int tmpfs_fsids_mapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_fsids_mapped);
> > +}
> > +static int tmpfs_fsids_unmapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_fsids_unmapped);
> > +}
> > +static int tmpfs_expected_uid_gid_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_expected_uid_gid_idmapped_mounts);
> > +}
> > +static int tmpfs_fscaps_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts);
> > +}
> > +static int tmpfs_fscaps_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns);
> > +}
> > +static int tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_fscaps_idmapped_mounts_in_userns_separate_userns);
> > +}
> > +
> > +static int tmpfs_hardlink_crossing_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_hardlink_crossing_idmapped_mounts);
> > +}
> > +static int tmpfs_hardlink_from_idmapped_mount(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount);
> > +}
> > +static int tmpfs_hardlink_from_idmapped_mount_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_hardlink_from_idmapped_mount_in_userns);
> > +}
> > +
> > +#ifdef HAVE_LIBURING_H
> > +static int tmpfs_io_uring_idmapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped);
> > +}
> > +static int tmpfs_io_uring_idmapped_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_userns);
> > +}
> > +static int tmpfs_io_uring_idmapped_unmapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped);
> > +}
> > +static int tmpfs_io_uring_idmapped_unmapped_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_io_uring_idmapped_unmapped_userns);
> > +}
> > +#endif /* HAVE_LIBURING_H */
> > +
> > +static int tmpfs_protected_symlinks_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts);
> > +}
> > +static int tmpfs_protected_symlinks_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_protected_symlinks_idmapped_mounts_in_userns);
> > +}
> > +static int tmpfs_rename_crossing_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_rename_crossing_idmapped_mounts);
> > +}
> > +static int tmpfs_rename_from_idmapped_mount(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount);
> > +}
> > +static int tmpfs_rename_from_idmapped_mount_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_rename_from_idmapped_mount_in_userns);
> > +}
> > +static int tmpfs_setattr_truncate_idmapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped);
> > +}
> > +static int tmpfs_setattr_truncate_idmapped_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setattr_truncate_idmapped_in_userns);
> > +}
> > +static int tmpfs_setgid_create_idmapped(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped);
> > +}
> > +static int tmpfs_setgid_create_idmapped_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setgid_create_idmapped_in_userns);
> > +}
> > +static int tmpfs_setid_binaries_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts);
> > +}
> > +static int tmpfs_setid_binaries_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns);
> > +}
> > +static int tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_setid_binaries_idmapped_mounts_in_userns_separate_userns);
> > +}
> > +static int tmpfs_sticky_bit_unlink_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts);
> > +}
> > +static int tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_unlink_idmapped_mounts_in_userns);
> > +}
> > +static int tmpfs_sticky_bit_rename_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts);
> > +}
> > +static int tmpfs_sticky_bit_rename_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_sticky_bit_rename_idmapped_mounts_in_userns);
> > +}
> > +static int tmpfs_symlink_idmapped_mounts(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts);
> > +}
> > +static int tmpfs_symlink_idmapped_mounts_in_userns(const struct vfstest_info *info)
> > +{
> > +	return tmpfs_nested_mount_setup(info, tcore_symlink_idmapped_mounts_in_userns);
> > +}
> > +
> > +static const struct test_struct t_tmpfs[] = {
> > +	{ tmpfs_acls,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
> > +	{ tmpfs_create_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in user namespace",							      },
> > +	{ tmpfs_device_node_in_userns,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs device node in user namespace",								      },
> > +	{ tmpfs_expected_uid_gid_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs expected ownership on idmapped mounts",							},
> > +	{ tmpfs_fscaps_idmapped_mounts,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts",									},
> > +	{ tmpfs_fscaps_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace",							},
> > +	{ tmpfs_fscaps_idmapped_mounts_in_userns_separate_userns,		T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs fscaps on idmapped mounts in user namespace with different id mappings",			},
> > +	{ tmpfs_fsids_mapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs mapped fsids",										      },
> > +	{ tmpfs_fsids_unmapped,							T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs unmapped fsids",										      },
> > +	{ tmpfs_hardlink_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount hardlink",								},
> > +	{ tmpfs_hardlink_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts",								},
> > +	{ tmpfs_hardlink_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs hardlinks from idmapped mounts in user namespace",						},
> > +#ifdef HAVE_LIBURING_H
> > +	{ tmpfs_io_uring_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts",								      },
> > +	{ tmpfs_io_uring_idmapped_userns,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts in user namespace",					      },
> > +	{ tmpfs_io_uring_idmapped_unmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids",					      },
> > +	{ tmpfs_io_uring_idmapped_unmapped_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs io_uring from idmapped mounts with unmapped ids in user namespace",			      },
> > +#endif
> > +	{ tmpfs_protected_symlinks_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts",						},
> > +	{ tmpfs_protected_symlinks_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs following protected symlinks on idmapped mounts in user namespace",				},
> > +	{ tmpfs_rename_crossing_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs cross idmapped mount rename",									},
> > +	{ tmpfs_rename_from_idmapped_mount,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts",									},
> > +	{ tmpfs_rename_from_idmapped_mount_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs rename from idmapped mounts in user namespace",						},
> > +	{ tmpfs_setattr_truncate_idmapped,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts",								},
> > +	{ tmpfs_setattr_truncate_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setattr truncate on idmapped mounts in user namespace",					},
> > +	{ tmpfs_setgid_create_idmapped,						T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts",			},
> > +	{ tmpfs_setgid_create_idmapped_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs create operations in directories with setgid bit set on idmapped mounts in user namespace",	},
> > +	{ tmpfs_setid_binaries_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts",								},
> > +	{ tmpfs_setid_binaries_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace",						},
> > +	{ tmpfs_setid_binaries_idmapped_mounts_in_userns_separate_userns,	T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs setid binaries on idmapped mounts in user namespace with different id mappings",		},
> > +	{ tmpfs_sticky_bit_unlink_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts",						},
> > +	{ tmpfs_sticky_bit_unlink_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit unlink operations on idmapped mounts in user namespace",				},
> > +	{ tmpfs_sticky_bit_rename_idmapped_mounts,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts",						},
> > +	{ tmpfs_sticky_bit_rename_idmapped_mounts_in_userns,			T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs sticky bit rename operations on idmapped mounts in user namespace",				},
> > +	{ tmpfs_symlink_idmapped_mounts,					T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts",									},
> > +	{ tmpfs_symlink_idmapped_mounts_in_userns,				T_REQUIRE_USERNS | T_REQUIRE_IDMAPPED_MOUNTS,	"tmpfs symlink from idmapped mounts in user namespace",						},
> > +};
> > +
> > +
> > +const struct test_suite s_tmpfs_idmapped_mounts = {
> > +	.tests = t_tmpfs,
> > +	.nr_tests = ARRAY_SIZE(t_tmpfs),
> > +};
> > diff --git src/vfs/tmpfs-idmapped-mounts.h src/vfs/tmpfs-idmapped-mounts.h
> > new file mode 100644
> > index 00000000..038d86a9
> > --- /dev/null
> > +++ src/vfs/tmpfs-idmapped-mounts.h
> > @@ -0,0 +1,15 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +
> > +#ifndef __TMPFS_IDMAPPED_MOUNTS_H
> > +#define __TMPFS_IDMAPPED_MOUNTS_H
> > +
> > +#ifndef _GNU_SOURCE
> > +#define _GNU_SOURCE
> > +#endif
> > +
> > +#include "utils.h"
> > +
> > +extern const struct test_suite s_tmpfs_idmapped_mounts;
> > +
> > +#endif /* __TMPFS_IDMAPPED_MOUNTS_H */
> > +
> > diff --git src/vfs/utils.h src/vfs/utils.h
> > index f1681737..872fd96f 100644
> > --- src/vfs/utils.h
> > +++ src/vfs/utils.h
> > @@ -45,6 +45,8 @@
> >  #define DIR2 "dir2"
> >  #define DIR3 "dir3"
> >  #define DIR1_RENAME "dir1_rename"
> > +// This directory may be used by tests that call another test.
> > +#define DIR0 "dir0"
> >  #define HARDLINK1 "hardlink1"
> >  #define SYMLINK1 "symlink1"
> >  #define SYMLINK_USER1 "symlink_user1"
> > diff --git src/vfs/vfstest.c src/vfs/vfstest.c
> > index 325f04a1..f842117d 100644
> > --- src/vfs/vfstest.c
> > +++ src/vfs/vfstest.c
> > @@ -23,6 +23,7 @@
> >  #include <unistd.h>
> >  
> >  #include "btrfs-idmapped-mounts.h"
> > +#include "tmpfs-idmapped-mounts.h"
> >  #include "idmapped-mounts.h"
> >  #include "missing.h"
> >  #include "utils.h"
> > @@ -2316,6 +2317,7 @@ static void usage(void)
> >  	fprintf(stderr, "--test-fscaps-regression            Run fscap regression tests\n");
> >  	fprintf(stderr, "--test-nested-userns                Run nested userns idmapped mount testsuite\n");
> >  	fprintf(stderr, "--test-btrfs                        Run btrfs specific idmapped mount testsuite\n");
> > +	fprintf(stderr, "--test-tmpfs                        Run tmpfs specific idmapped mount testsuite\n");
> >  	fprintf(stderr, "--test-setattr-fix-968219708108     Run setattr regression tests\n");
> >  	fprintf(stderr, "--test-setxattr-fix-705191b03d50    Run setxattr regression tests\n");
> >  	fprintf(stderr, "--test-setgid-create-umask          Run setgid with umask tests\n");
> > @@ -2340,6 +2342,7 @@ static const struct option longopts[] = {
> >  	{"test-setxattr-fix-705191b03d50",	no_argument,		0,	'j'},
> >  	{"test-setgid-create-umask",		no_argument,		0,	'u'},
> >  	{"test-setgid-create-acl",		no_argument,		0,	'l'},
> > +	{"test-tmpfs",				no_argument,		0,	't'},
> >  	{NULL,					0,			0,	  0},
> >  };
> >  
> > @@ -2480,7 +2483,7 @@ int main(int argc, char *argv[])
> >  	bool idmapped_mounts_supported = false, test_btrfs = false,
> >  	     test_core = false, test_fscaps_regression = false,
> >  	     test_nested_userns = false, test_setattr_fix_968219708108 = false,
> > -	     test_setxattr_fix_705191b03d50 = false,
> > +	     test_setxattr_fix_705191b03d50 = false, test_tmpfs = false,
> >  	     test_setgid_create_umask = false, test_setgid_create_acl = false;
> >  
> >  	init_vfstest_info(&info);
> > @@ -2529,6 +2532,9 @@ int main(int argc, char *argv[])
> >  		case 'l':
> >  			test_setgid_create_acl = true;
> >  			break;
> > +		case 't':
> > +			test_tmpfs = true;
> > +			break;
> >  		case 'h':
> >  			/* fallthrough */
> >  		default:
> > @@ -2622,6 +2628,11 @@ int main(int argc, char *argv[])
> >  			goto out;
> >  	}
> >  
> > +	if (test_tmpfs) {
> > +		if (!run_suite(&info, &s_tmpfs_idmapped_mounts))
> > +			goto out;
> > +	}
> > +
> >  	fret = EXIT_SUCCESS;
> >  
> >  out:
> > diff --git tests/tmpfs/001 tests/tmpfs/001
> > new file mode 100755
> > index 00000000..37f5439e
> > --- /dev/null
> > +++ tests/tmpfs/001
> > @@ -0,0 +1,27 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2023 Rodrigo Campos Catelin.  All Rights Reserved.
> > +#
> > +# FS QA Test 001
> > +#
> > +# Test that idmapped mounts behave correctly with tmpfs filesystem.
> > +#
> > +. ./common/preamble
> > +_begin_fstest auto quick idmapped
> > +
> > +# get standard environment, filters and checks
> > +. ./common/filter
> > +
> > +# real QA test starts here
> > +
> > +_supported_fs tmpfs
> > +_require_idmapped_mounts
> > +_require_test
> > +
> > +echo "Silence is golden"
> > +
> > +$here/src/vfs/vfstest --test-tmpfs --device "$TEST_DEV" \
> > +	        --mount "$TEST_DIR" --fstype "$FSTYP"
> > +
> > +status=$?
> > +exit
> > diff --git tests/tmpfs/001.out tests/tmpfs/001.out
> > new file mode 100644
> > index 00000000..88678b8e
> > --- /dev/null
> > +++ tests/tmpfs/001.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 001
> > +Silence is golden
> > diff --git tests/tmpfs/Makefile tests/tmpfs/Makefile
> > new file mode 100644
> > index 00000000..b464b22b
> > --- /dev/null
> > +++ tests/tmpfs/Makefile
> > @@ -0,0 +1,24 @@
> > +#
> > +# Copyright (c) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
> > +#
> > +
> > +TOPDIR = ../..
> > +include $(TOPDIR)/include/builddefs
> > +include $(TOPDIR)/include/buildgrouplist
> > +
> > +GENERIC_DIR = generic
> > +TARGET_DIR = $(PKG_LIB_DIR)/$(TESTS_DIR)/$(GENERIC_DIR)
> > +DIRT = group.list
> > +
> > +default: $(DIRT)
> > +
> > +include $(BUILDRULES)
> > +
> > +install:
> > +	$(INSTALL) -m 755 -d $(TARGET_DIR)
> > +	$(INSTALL) -m 755 $(TESTS) $(TARGET_DIR)
> > +	$(INSTALL) -m 644 group.list $(TARGET_DIR)
> > +	$(INSTALL) -m 644 $(OUTFILES) $(TARGET_DIR)
> > +
> > +# Nothing.
> > +install-dev install-lib:
> > -- 
> > 2.39.2
> > 
> 

Re: [PATCH v2 9/9] vfs: Add tmpfs tests for idmap mounts

[Rodrigo Campos]

On 3/13/23 11:50, Christian Brauner wrote:
> On Wed, Mar 08, 2023 at 12:13:43PM +0100, Rodrigo Campos wrote:
>> +	/* create separate mount namespace */
>> +	if (unshare(CLONE_NEWNS)) {
>> +		log_stderr("failure: create new mount namespace");
>> +		goto out_no_rm;
>> +	}
> 
> I think you might want to turn off mount propagation here so that the
> tmpfs mount doesn't propagate into the parent mount namespace:
> 
> 	mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0)

Right, great catch!


>> +	// Create a new info to use for test we will call.
>> +	struct vfstest_info nested_test_info = *info;
> 
> nit: We usually don't mix declarations and code in C code so I would
> move that struct vfstest_info to the top of the function.

Heh, I prefer C99 declarations, but sorry I forgot we are not using that 
style in these files. I'll fix it :)

> 
>> +	nested_test_info.t_mountpoint = strdup(path);
>> +	if (nested_test_info.t_mountpoint == NULL) {
> 
> nit: more idiomatic
> if (!nested_test_info.t_mountpoint)

Thanks!

>> +	if(rm_r(info->t_mnt_fd, DIR0)) >
> nit: missing space between "if" and "("

Ouch, probably my scripts for the spacing patch mixed this up... Fixed!