On Sat, Sep 05 2026, Amir Goldstein wrote:
> 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
ACK.
>> + else {
>> + if (!strcmp(name, DIRNAME)) {
>
> This condition is already guaranteed when we get here
*sigh*
Yeah, likely leftover code from the symlink cache test I used as base.
>> + 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?
Good point. That value should probably be kept in the test state
structure.
Cheers,
--
Luís
> 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
