On Fri, Sep 4, 2026 at 12:38 PM Luis Henriques <[email protected]> wrote: > > 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 <[email protected]> > --- > .../selftests/filesystems/fuse/.gitignore | 1 + > .../selftests/filesystems/fuse/Makefile | 2 + > .../fuse/fuse_symlink_cache_test.c | 167 ++++++++++++++++++ > 3 files changed, 170 insertions(+) > create mode 100644 > tools/testing/selftests/filesystems/fuse/fuse_symlink_cache_test.c > > diff --git a/tools/testing/selftests/filesystems/fuse/.gitignore > b/tools/testing/selftests/filesystems/fuse/.gitignore > index f7f3dd345a50..ebfe7133d811 100644 > --- a/tools/testing/selftests/filesystems/fuse/.gitignore > +++ b/tools/testing/selftests/filesystems/fuse/.gitignore > @@ -3,3 +3,4 @@ fuse_mnt > fusectl_test > write_extend_eof_test > fuse_acl_cache_test > +fuse_symlink_cache_test > diff --git a/tools/testing/selftests/filesystems/fuse/Makefile > b/tools/testing/selftests/filesystems/fuse/Makefile > index 7744f796eb06..3a5a557dde7a 100644 > --- a/tools/testing/selftests/filesystems/fuse/Makefile > +++ b/tools/testing/selftests/filesystems/fuse/Makefile > @@ -5,6 +5,7 @@ CFLAGS += -Wall -O2 -g $(KHDR_INCLUDES) > TEST_GEN_PROGS := fusectl_test > TEST_GEN_PROGS += write_extend_eof_test > TEST_GEN_PROGS += fuse_acl_cache_test > +TEST_GEN_PROGS += fuse_symlink_cache_test > TEST_GEN_FILES := fuse_mnt > > include ../../lib.mk > @@ -28,5 +29,6 @@ $(OUTPUT)/fuse_mnt: CFLAGS += $(VAR_CFLAGS) > $(OUTPUT)/fuse_mnt: LDLIBS += $(VAR_LDLIBS) > > $(OUTPUT)/fuse_acl_cache_test: fuse_common.c fuse_acl_cache_test.c > +$(OUTPUT)/fuse_symlink_cache_test: fuse_common.c fuse_symlink_cache_test.c > > EXTRA_CLEAN := fuse_common.o > diff --git > a/tools/testing/selftests/filesystems/fuse/fuse_symlink_cache_test.c > b/tools/testing/selftests/filesystems/fuse/fuse_symlink_cache_test.c > new file mode 100644 > index 000000000000..ca3c5cdaf578 > --- /dev/null > +++ b/tools/testing/selftests/filesystems/fuse/fuse_symlink_cache_test.c > @@ -0,0 +1,167 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Simple filesystem to test FUSE symlink cache > + * > + * This is a simple FUSE filesystem that contains two objects: a file named > + * 'file' and a symlink to that file named 'link'. If symlink caching is > + * disabled (i.e. FUSE_CAP_CACHE_SYMLINKS is reset during FUSE_INIT), > whenever > + * the ->readlink() is executed to resolve 'link' a counter will be > incremented. > + * > + * If symlink caching is enabled (i.e. FUSE_CAP_CACHE_SYMLINKS is set during > + * FUSE_INIT), resolving a symlink will only call into user-space the first > + * time. > + */ > + > +#define FUSE_USE_VERSION 31 > + > +#include <stdio.h> > +#include <limits.h> > +#include <fuse_lowlevel.h> > + > +#include "kselftest_harness.h" > + > +#include "fuse_common.h" > + > +#define FILENAME "file" > +#define FILE_INO 42 > + > +#define LINKNAME "link" > +#define LINK_INO 43 > + > +#define TIMEOUT 86400.0f > + > +struct test_state { > + pthread_mutex_t lock; > + bool cache; > + int readlink_counter; > +} test_state = { > + .lock = PTHREAD_MUTEX_INITIALIZER, > +}; > + > +static void fs_init(void *userdata, struct fuse_conn_info *conn) > +{ > + pthread_mutex_lock(&test_state.lock); > + if (test_state.cache) > + fuse_set_feature_flag(conn, FUSE_CAP_CACHE_SYMLINKS); > + else > + fuse_unset_feature_flag(conn, FUSE_CAP_CACHE_SYMLINKS); > + pthread_mutex_unlock(&test_state.lock); > +} > + > +static void fs_lookup(fuse_req_t req, fuse_ino_t parent, const char *name) > +{ > + struct fuse_entry_param e = {}; > + > + if (parent != FUSE_ROOT_ID || > + (!strcmp(name, FILENAME) && !(strcmp(name, LINKNAME))))
You probably meant strcmp() != 0 ... Did you miss this Sashiko comment? Thanks, Amir.
