linux-toradex.git/tools/testing/selftests/filesystems/fuse, branch master

selftests/fuse: add the missing symlink caching test

2026-10-31T00:22:37+00:00

Commit 3e14f079d7a0 ("selftests/fuse: add fuse symlink caching test")
registered fuse_symlink_cache_test in the fuse selftest Makefile and
.gitignore, but the test source was not part of the applied commit, so
building the fuse selftests fails:

  make[1]: *** No rule to make target 'fuse_symlink_cache_test.c', needed by '.../fuse_symlink_cache_test'.

Add fuse_symlink_cache_test.c as posted in Luis Henriques's v5
submission. The test serves a file and a symlink to it from a libfuse
low-level filesystem, resolves the symlink 100 times, and counts the
readlink requests that reach the server: one when FUSE_CAP_CACHE_SYMLINKS
is set during FUSE_INIT, and all 100 when it is not.

Fixes: 3e14f079d7a0 ("selftests/fuse: add fuse symlink caching test")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/r/202610170822.oEJ1Autq-lkp@intel.com/
Link: https://lore.kernel.org/r/20261001164916.15311-8-luis@igalia.com
Originally-by: Luis Henriques 
Signed-off-by: Sasha Levin 
Reviewed-by: Luis Henriques 
Signed-off-by: Linus Torvalds

selftests/fuse: add the missing FUSE_HAS_SYNCFS privilege test

2026-10-16T10:17:07+00:00

Commit a6ca1a573e1f ("selftests/fuse: add test for FUSE_HAS_SYNCFS
privilege gating") registered test_syncfs in the fuse selftest Makefile
and .gitignore, but the test source was not part of the applied commit,
so building the fuse selftests fails:

  make[1]: *** No rule to make target '.../test_syncfs', needed by 'all'.

Add test_syncfs.c as posted in Jimmy Zuber's v3 submission. The test
talks the raw FUSE protocol over /dev/fuse, so it can choose whether to
advertise FUSE_HAS_SYNCFS and directly observe whether the kernel
forwards a FUSE_SYNCFS request. It covers three cases:

  T1: host-root mount, server sets FUSE_HAS_SYNCFS
      -> FUSE_SYNCFS must reach the server.
  T2: host-root mount, server does not opt in
      -> FUSE_SYNCFS must not be sent (back-compat).
  T3: server opts in but opened /dev/fuse without CAP_SYS_ADMIN while
      still in the initial user namespace
      -> FUSE_SYNCFS must be withheld.

Fixes: a6ca1a573e1f ("selftests/fuse: add test for FUSE_HAS_SYNCFS privilege gating")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/r/202609021808.5OxsIter-lkp@intel.com/
Closes: https://lore.kernel.org/r/202609230913.G4keWCG7-lkp@intel.com/
Link: https://lore.kernel.org/r/20260820130158.254808-3-jamz@amazon.com
Originally-by: Jimmy Zuber 
Signed-off-by: Sasha Levin 
Signed-off-by: Miklos Szeredi

selftests/fuse: add fuse readdir caching test

2026-10-15T12:01:52+00:00

This new test will check the caching behaviour using combinations of two
opendir flags: FOPEN_KEEP_CACHE and FOPEN_CACHE_DIR.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: add fuse symlink caching test

2026-10-15T12:01:51+00:00

This patch adds a simple test that allows to verify that, when resolving a
symlink, user-space is called only the first time when caching is enabled
or, if caching is disabled, every time the symlink resolution is requested.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: add some extra ACL caching tests

2026-10-15T12:01:34+00:00

This adds some extra tests to ACL caching:
- Verify that reading ACLs results in the expected number of requests
  being sent user-space, depending on whether cache is enabled or disabled
- Verify caching behaviour on some caching invalidation scenarios

While there, add test binary to .gitignore.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: use dynamically allocated memory to store ACLs

2026-10-15T12:01:13+00:00

Instead of directly using static arrays for the ACL value, allocate memory
for storing it.  This will make it easier to implement ACL tests that also
set the xattr dynamically.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: factor-out test fixture setup/teardown

2026-10-15T12:01:13+00:00

In order to reduce new tests setup/teardown code duplication, factor-out
these functions from the existing acl_cache test into a new fuse_common.c
file that can be reused in other tests.

While there, also move some of the FIXTURE members into a fuse_common_ctx
structure that can be passed into setup/teardown instead of passing them by
reference.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: check that fusectlfs is mounted

2026-10-15T12:01:13+00:00

The control filesystem for FUSE needs to be mounted for the fusectl_test to
be successfully run.  Skip the test is that is not the case.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: convert fusectl test to fuse3

2026-10-15T12:01:12+00:00

Since it is probably not worth adding new fuse kselftests based on fuse2,
it is a good idea to convert the single existing test to fuse3.  The
conversion is trivial, as it only requires some changes to function
signatures (the gettattr and truncate fuse operations), and to the filler()
helper.

Signed-off-by: Luis Henriques 
Reviewed-by: Amir Goldstein 
Signed-off-by: Miklos Szeredi

selftests/fuse: add test for FUSE_HAS_SYNCFS privilege gating

2026-09-02T07:36:07+00:00

Add a selftest that talks the raw FUSE protocol over /dev/fuse (rather
than via libfuse, which negotiates INIT internally) so it can both choose
whether to advertise FUSE_HAS_SYNCFS and directly observe whether a
FUSE_SYNCFS opcode is forwarded by the kernel.

Three cases are covered:

  T1: host-root mount, server sets FUSE_HAS_SYNCFS
      -> FUSE_SYNCFS must reach the server.
  T2: host-root mount, server does not opt in
      -> FUSE_SYNCFS must not be sent (back-compat).
  T3: server opts in but opened /dev/fuse without CAP_SYS_ADMIN while still
      in the initial user namespace
      -> FUSE_SYNCFS must be withheld.  This is the case that distinguishes
         gating on the server's privilege from gating on the mount's user
         namespace.

Signed-off-by: Jimmy Zuber 
Assisted-by: Claude:claude-opus-4-8 [Claude-Code]
Signed-off-by: Miklos Szeredi