On Fri, Sep 4, 2026 at 12:38 PM Luis Henriques <[email protected]> wrote:
>
> 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 <[email protected]>
> ---
> .../selftests/filesystems/fuse/.gitignore | 1 +
> .../selftests/filesystems/fuse/Makefile | 2 +
> .../fuse/fuse_readdir_cache_test.c | 274 ++++++++++++++++++
> 3 files changed, 277 insertions(+)
> create mode 100644
> tools/testing/selftests/filesystems/fuse/fuse_readdir_cache_test.c
>
> diff --git a/tools/testing/selftests/filesystems/fuse/.gitignore
> b/tools/testing/selftests/filesystems/fuse/.gitignore
> index ebfe7133d811..ffa356f23e8c 100644
> --- a/tools/testing/selftests/filesystems/fuse/.gitignore
> +++ b/tools/testing/selftests/filesystems/fuse/.gitignore
> @@ -4,3 +4,4 @@ fusectl_test
> write_extend_eof_test
> fuse_acl_cache_test
> fuse_symlink_cache_test
> +fuse_readdir_cache_test
> diff --git a/tools/testing/selftests/filesystems/fuse/Makefile
> b/tools/testing/selftests/filesystems/fuse/Makefile
> index 3a5a557dde7a..570ced181168 100644
> --- a/tools/testing/selftests/filesystems/fuse/Makefile
> +++ b/tools/testing/selftests/filesystems/fuse/Makefile
> @@ -6,6 +6,7 @@ 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_PROGS += fuse_readdir_cache_test
> TEST_GEN_FILES := fuse_mnt
>
> include ../../lib.mk
> @@ -30,5 +31,6 @@ $(OUTPUT)/fuse_mnt: LDLIBS += $(VAR_LDLIBS)
>
> $(OUTPUT)/fuse_acl_cache_test: fuse_common.c fuse_acl_cache_test.c
> $(OUTPUT)/fuse_symlink_cache_test: fuse_common.c fuse_symlink_cache_test.c
> +$(OUTPUT)/fuse_readdir_cache_test: fuse_common.c fuse_readdir_cache_test.c
>
> EXTRA_CLEAN := fuse_common.o
> diff --git
> a/tools/testing/selftests/filesystems/fuse/fuse_readdir_cache_test.c
> b/tools/testing/selftests/filesystems/fuse/fuse_readdir_cache_test.c
> new file mode 100644
> index 000000000000..7c49cc6a23e3
> --- /dev/null
> +++ b/tools/testing/selftests/filesystems/fuse/fuse_readdir_cache_test.c
> @@ -0,0 +1,274 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Simple filesystem to test FUSE readdir cache
> + *
> + * It will simply perform readdir operations on a directory checking how many
> + * times a request is sent to user-space using all the possible caching
> + * combination setting (FOPEN_KEEP_CACHE and FOPEN_CACHE_DIR flags).
> + */
> +
> +#include <stdio.h>
> +#include <limits.h>
> +#include <dirent.h>
> +
> +#include "kselftest_harness.h"
> +
> +#include "fuse_common.h"
> +
> +#define DIRNAME "mydir"
> +#define FILENAME "myfile"
> +
> +#define DIR_INO 42
> +#define FILE_INO 43
> +#define DOT_INO 40
> +#define DOTDOT_INO 41
> +
> +#define TIMEOUT 86400.0f
> +
> +struct test_state {
> + pthread_mutex_t lock;
> + bool cache_readdir;
> + bool keep_cache;
> + int readdir_counter;
> +} test_state = {
> + .lock = PTHREAD_MUTEX_INITIALIZER,
> +};
> +
> +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, DIRNAME) != 0)
> + fuse_reply_err(req, ENOENT);
Again: allergic to non matching {} and can just return here no need
for all this nesting
> + else {
> + if (!strcmp(name, DIRNAME)) {
This condition is already guaranteed when we get here
> + e.ino = DIR_INO;
> + e.attr.st_mode = S_IFDIR | 0755;
> + e.attr.st_nlink = 1;
> + } else {
> + e.ino = FUSE_ROOT_ID;
> + e.attr.st_mode = S_IFDIR | 0755;
> + e.attr.st_nlink = 2;
> + }
> + e.attr.st_mtime = time(NULL);
> + e.attr_timeout = TIMEOUT;
> + e.entry_timeout = TIMEOUT;
> + fuse_reply_entry(req, &e);
> + }
> +}
> +
> +static int fill_stat(fuse_ino_t ino, struct stat *st)
> +{
> + int ret = 0;
> +
> + st->st_ino = ino;
> + st->st_mtime = time(NULL);
Doesn't this need to be a const value?
to make sure that it does not change from here to lookup time?
Thanks,
Amir.
> +
> + switch (ino) {
> + case FUSE_ROOT_ID:
> + st->st_mode = S_IFDIR | 0755;
> + st->st_nlink = 2;
> + break;
> + case DOT_INO:
> + case DOTDOT_INO:
> + case DIR_INO:
> + st->st_mode = S_IFDIR | 0755;
> + st->st_nlink = 1;
> + break;
> + case FILE_INO:
> + st->st_mode = S_IFREG | 0444;
> + st->st_nlink = 1;
> + break;
> + default:
> + ret = -1;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static void fs_getattr(fuse_req_t req, fuse_ino_t ino,
> + struct fuse_file_info *fi)
> +{
> + struct stat st = {};
> +
> + if (fill_stat(ino, &st) < 0)
> + fuse_reply_err(req, ENOENT);
> + else
> + fuse_reply_attr(req, &st, TIMEOUT);
> +}
> +
> +static void fs_opendir(fuse_req_t req, fuse_ino_t ino,
> + struct fuse_file_info *fi)
> +{
> + pthread_mutex_lock(&test_state.lock);
> + fi->keep_cache = test_state.keep_cache;
> + fi->cache_readdir = test_state.cache_readdir;
> + pthread_mutex_unlock(&test_state.lock);
> + fuse_reply_open(req, fi);
> +}
> +
> +static void fs_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
> + off_t offset, struct fuse_file_info *fi)
> +{
> + struct stat st = {};
> + char buf[1024];
> + char *pbuf;
> + size_t rem = size;
> + size_t sz;
> + int nextoff = 0;
> +
> + if (ino != DIR_INO) {
> + fuse_reply_err(req, ENOTDIR);
> + return;
> + }
> + if (offset) {
> + fuse_reply_buf(req, NULL, 0);
> + return;
> + }
> + pbuf = buf;
> + fill_stat(DOT_INO, &st);
> + sz = fuse_add_direntry(req, pbuf, rem, ".", &st, nextoff++);
> + rem -= sz;
> + pbuf += sz;
> + fill_stat(DOTDOT_INO, &st);
> + sz = fuse_add_direntry(req, pbuf, rem, "..", &st, nextoff++);
> + rem -= sz;
> + pbuf += sz;
> + fill_stat(FILE_INO, &st);
> + sz = fuse_add_direntry(req, pbuf, rem, FILENAME, &st, nextoff++);
> + rem -= sz;
> +
> + fuse_reply_buf(req, buf, size - rem);
> +
> + pthread_mutex_lock(&test_state.lock);
> + test_state.readdir_counter++;
> + pthread_mutex_unlock(&test_state.lock);
> +}
> +
> +static const struct fuse_lowlevel_ops fs_ops = {
> + .lookup = fs_lookup,
> + .getattr = fs_getattr,
> + .opendir = fs_opendir,
> + .readdir = fs_readdir,
> +};
> +
> +FIXTURE(readdir_cache)
> +{
> + struct fuse_session *se;
> + char mountpoint[MOUNTPOINT_SZ];
> + pthread_t thread;
> +};
> +
> +FIXTURE_VARIANT(readdir_cache)
> +{
> + bool cache_readdir;
> + bool keep_cache;
> +};
> +FIXTURE_VARIANT_ADD(readdir_cache, nocache)
> +{
> + .cache_readdir = false,
> + .keep_cache = false,
> +};
> +FIXTURE_VARIANT_ADD(readdir_cache, cache_readdir)
> +{
> + .cache_readdir = true,
> + .keep_cache = false,
> +};
> +FIXTURE_VARIANT_ADD(readdir_cache, keep_cache)
> +{
> + .cache_readdir = false,
> + .keep_cache = true,
> +};
> +FIXTURE_VARIANT_ADD(readdir_cache, cache)
> +{
> + .cache_readdir = true,
> + .keep_cache = true,
> +};
> +
> +FIXTURE_SETUP(readdir_cache)
> +{
> + char err[MAX_ERR_MSG];
> +
> + pthread_mutex_lock(&test_state.lock);
> + test_state.readdir_counter = 0;
> + test_state.cache_readdir = variant->cache_readdir;
> + test_state.keep_cache = variant->keep_cache;
> + pthread_mutex_unlock(&test_state.lock);
> +
> + if (fs_setup(&self->se, self->mountpoint, &fs_ops, &self->thread,
> err))
> + SKIP(return, err);
> +}
> +
> +FIXTURE_TEARDOWN(readdir_cache)
> +{
> + fs_teardown(self->se, self->thread, self->mountpoint);
> +}
> +
> +TEST_F(readdir_cache, test_readdir_cache)
> +{
> + struct dirent *dentry;
> + DIR *dir;
> + char pathname[PATH_MAX];
> + int total_counter, rewind_counter;
> + int dentrycount;
> +
> + sprintf(pathname, "%s/%s", self->mountpoint, DIRNAME);
> +
> + dir = opendir(pathname);
> + if (dir == NULL)
> + TH_LOG("opendir(): %s", strerror(errno));
> + ASSERT_NE(dir, NULL);
> +
> + errno = 0;
> + dentrycount = 0;
> + while ((dentry = readdir(dir)))
> + dentrycount++;
> + ASSERT_EQ(errno, 0);
> + ASSERT_EQ(dentrycount, 3);
> +
> + rewinddir(dir);
> + errno = 0;
> + dentrycount = 0;
> + while ((dentry = readdir(dir)))
> + dentrycount++;
> + ASSERT_EQ(errno, 0);
> + ASSERT_EQ(dentrycount, 3);
> +
> + ASSERT_EQ(closedir(dir), 0);
> +
> + pthread_mutex_lock(&test_state.lock);
> + rewind_counter = test_state.readdir_counter;
> + pthread_mutex_unlock(&test_state.lock);
> +
> + dir = opendir(pathname);
> + if (dir == NULL)
> + TH_LOG("opendir(): %s", strerror(errno));
> + ASSERT_NE(dir, NULL);
> +
> + errno = 0;
> + dentrycount = 0;
> + while ((dentry = readdir(dir)))
> + dentrycount++;
> + ASSERT_EQ(errno, 0);
> + ASSERT_EQ(dentrycount, 3);
> +
> + ASSERT_EQ(closedir(dir), 0);
> +
> + pthread_mutex_lock(&test_state.lock);
> + total_counter = test_state.readdir_counter;
> + pthread_mutex_unlock(&test_state.lock);
> +
> + if (!variant->cache_readdir) {
> + ASSERT_EQ(rewind_counter, 2);
> + ASSERT_EQ(total_counter, 3);
> + } else if (!variant->keep_cache) {
> + ASSERT_EQ(rewind_counter, 1);
> + ASSERT_EQ(total_counter, 2);
> + } else {
> + ASSERT_EQ(rewind_counter, 1);
> + ASSERT_EQ(total_counter, 1);
> + }
> +}
> +
> +TEST_HARNESS_MAIN
