[LTP] [PATCH 2/5] syscalls/fanotify23: Introduce FAN_MARK_EVICTABLE test
Jan Kara
jack@suse.cz
Tue Jun 14 12:19:17 CEST 2022
On Mon 13-06-22 17:38:23, Amir Goldstein wrote:
> Verify that evictable mark does not pin inode to cache and that
> drop_caches evicts inode from cache and removes the evictable mark.
>
> Verify that evictable mark can be upgraded to non-evictable but not
> downgraded to evictable afterwards.
>
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> runtest/syscalls | 1 +
> testcases/kernel/syscalls/fanotify/.gitignore | 1 +
> testcases/kernel/syscalls/fanotify/fanotify.h | 4 +
> .../kernel/syscalls/fanotify/fanotify23.c | 258 ++++++++++++++++++
> 4 files changed, 264 insertions(+)
> create mode 100644 testcases/kernel/syscalls/fanotify/fanotify23.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 1259e41f1..e9ee6e5ba 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -612,6 +612,7 @@ fanotify19 fanotify19
> fanotify20 fanotify20
> fanotify21 fanotify21
> fanotify22 fanotify22
> +fanotify23 fanotify23
>
> ioperm01 ioperm01
> ioperm02 ioperm02
> diff --git a/testcases/kernel/syscalls/fanotify/.gitignore b/testcases/kernel/syscalls/fanotify/.gitignore
> index 6d4ab4ca3..a0a7d20d3 100644
> --- a/testcases/kernel/syscalls/fanotify/.gitignore
> +++ b/testcases/kernel/syscalls/fanotify/.gitignore
> @@ -20,4 +20,5 @@
> /fanotify20
> /fanotify21
> /fanotify22
> +/fanotify23
> /fanotify_child
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify.h b/testcases/kernel/syscalls/fanotify/fanotify.h
> index eb690e332..0ad7ef21b 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify.h
> +++ b/testcases/kernel/syscalls/fanotify/fanotify.h
> @@ -101,6 +101,10 @@ static inline int safe_fanotify_mark(const char *file, const int lineno,
> #ifndef FAN_MARK_FILESYSTEM
> #define FAN_MARK_FILESYSTEM 0x00000100
> #endif
> +#ifndef FAN_MARK_EVICTABLE
> +#define FAN_MARK_EVICTABLE 0x00000200
> +#endif
> +
> /* New dirent event masks */
> #ifndef FAN_ATTRIB
> #define FAN_ATTRIB 0x00000004
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify23.c b/testcases/kernel/syscalls/fanotify/fanotify23.c
> new file mode 100644
> index 000000000..64787d627
> --- /dev/null
> +++ b/testcases/kernel/syscalls/fanotify/fanotify23.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022 CTERA Networks. All Rights Reserved.
> + *
> + * Author: Amir Goldstein <amir73il@gmail.com>
> + */
> +
> +/*\
> + * [Description]
> + * Check evictable fanotify inode marks.
> + */
> +
> +#define _GNU_SOURCE
> +#include "config.h"
> +
> +#include <stdio.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <errno.h>
> +#include <string.h>
> +#include <sys/syscall.h>
> +#include "tst_test.h"
> +
> +#ifdef HAVE_SYS_FANOTIFY_H
> +#include "fanotify.h"
> +
> +#define EVENT_MAX 1024
> +/* size of the event structure, not counting name */
> +#define EVENT_SIZE (sizeof (struct fanotify_event_metadata))
> +/* reasonable guess as to size of 1024 events */
> +#define EVENT_BUF_LEN (EVENT_MAX * EVENT_SIZE)
> +
> +#define MOUNT_PATH "fs_mnt"
> +#define TEST_FILE MOUNT_PATH "/testfile"
> +
> +#define DROP_CACHES_FILE "/proc/sys/vm/drop_caches"
> +#define CACHE_PRESSURE_FILE "/proc/sys/vm/vfs_cache_pressure"
> +
> +static int old_cache_pressure;
> +static int fd_notify;
> +
> +static unsigned long long event_set[EVENT_MAX];
> +
> +static char event_buf[EVENT_BUF_LEN];
> +
> +static void fsync_file(const char *path)
> +{
> + int fd = SAFE_OPEN(path, O_RDONLY);
> +
> + SAFE_FSYNC(fd);
> + SAFE_CLOSE(fd);
> +}
> +
> +/* Flush out all pending dirty inodes and destructing marks */
> +static void mount_cycle(void)
> +{
> + SAFE_UMOUNT(MOUNT_PATH);
> + SAFE_MOUNT(tst_device->dev, MOUNT_PATH, tst_device->fs_type, 0, NULL);
> +}
> +
> +static int verify_mark_removed(const char *path, const char *when)
> +{
> + int ret;
> +
> + /*
> + * We know that inode with evictable mark was evicted when a
> + * bogus call remove ACCESS from event mask returns ENOENT.
> + */
> + errno = 0;
> + ret = fanotify_mark(fd_notify, FAN_MARK_REMOVE,
> + FAN_ACCESS, AT_FDCWD, path);
> + if (ret == -1 && errno == ENOENT) {
> + tst_res(TPASS,
> + "FAN_MARK_REMOVE failed with ENOENT as expected"
> + " %s", when);
> + return 1;
> + } else {
> + tst_res(TFAIL | TERRNO,
> + "FAN_MARK_REMOVE did not fail with ENOENT as expected"
> + " %s", when);
> + return 0;
> + }
> +}
> +
> +static void test_fanotify(void)
> +{
> + int ret, len, test_num = 0;
> + struct fanotify_event_metadata *event;
> + int tst_count = 0;
> +
> + fd_notify = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF | FAN_REPORT_FID |
> + FAN_NONBLOCK, O_RDONLY);
> +
> + /*
> + * Verify that evictable mark can be upgraded to non-evictable
> + * and cannot be downgraded to evictable.
> + */
> + SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_ADD | FAN_MARK_EVICTABLE,
> + FAN_ACCESS,
> + AT_FDCWD, TEST_FILE);
> + SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_ADD,
> + FAN_ACCESS,
> + AT_FDCWD, TEST_FILE);
> + errno = 0;
> + ret = fanotify_mark(fd_notify, FAN_MARK_ADD | FAN_MARK_EVICTABLE,
> + FAN_ACCESS,
> + AT_FDCWD, TEST_FILE);
> + if (ret == -1 && errno == EEXIST) {
> + tst_res(TPASS,
> + "FAN_MARK_ADD failed with EEXIST as expected"
> + " when trying to downgrade to evictable mark");
> + } else {
> + tst_res(TFAIL | TERRNO,
> + "FAN_MARK_ADD did not fail with EEXIST as expected"
> + " when trying to downgrade to evictable mark");
> + }
> + SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_REMOVE,
> + FAN_ACCESS,
> + AT_FDCWD, TEST_FILE);
> + verify_mark_removed(TEST_FILE, "after empty mask");
> +
> +
> + /*
> + * Watch ATTRIB events on entire mount
> + */
> + SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_ADD | FAN_MARK_FILESYSTEM,
> + FAN_ATTRIB, AT_FDCWD, MOUNT_PATH);
> +
> + /*
> + * Generate events
> + */
> + SAFE_CHMOD(TEST_FILE, 0600);
> + event_set[tst_count] = FAN_ATTRIB;
> + tst_count++;
> +
> + /* Read events so far */
> + ret = SAFE_READ(0, fd_notify, event_buf, EVENT_BUF_LEN);
> + len = ret;
> +
> + /*
> + * Evictable mark on file ignores ATTRIB events
> + */
> + SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_ADD | FAN_MARK_EVICTABLE |
> + FAN_MARK_IGNORED_MASK | FAN_MARK_IGNORED_SURV_MODIFY,
> + FAN_ATTRIB, AT_FDCWD, TEST_FILE);
> +
> + /* ATTRIB event should be ignored */
> + SAFE_CHMOD(TEST_FILE, 0600);
> +
> + /*
> + * Read events to verify event was ignored
> + */
> + ret = read(fd_notify, event_buf + len, EVENT_BUF_LEN - len);
> + if (ret < 0 && errno == EAGAIN) {
> + tst_res(TPASS, "Got no events as expected");
> + } else {
> + tst_res(TFAIL, "Got expected events");
> + len += ret;
> + }
> +
> + /*
> + * drop_caches should evict inode from cache and remove evictable mark
> + */
> + fsync_file(TEST_FILE);
> + SAFE_FILE_PRINTF(DROP_CACHES_FILE, "3");
> +
> + verify_mark_removed(TEST_FILE, "after drop_caches");
> +
> + SAFE_CHMOD(TEST_FILE, 0600);
> + event_set[tst_count] = FAN_ATTRIB;
> + tst_count++;
> +
> + /* Read events to verify ATTRIB event was properly generated */
> + ret = SAFE_READ(0, fd_notify, event_buf + len, EVENT_BUF_LEN - len);
> + len += ret;
> +
> + /*
> + * Check events
> + */
> + event = (struct fanotify_event_metadata *)event_buf;
> +
> + /* Iterate over and validate events against expected result set */
> + while (FAN_EVENT_OK(event, len) && test_num < tst_count) {
> + if (!(event->mask & event_set[test_num])) {
> + tst_res(TFAIL,
> + "got event: mask=%llx (expected %llx)",
> + (unsigned long long)event->mask,
> + event_set[test_num]);
> + } else {
> + tst_res(TPASS,
> + "got event: mask=%llx",
> + (unsigned long long)event->mask);
> + }
> + /*
> + * Close fd and invalidate it so that we don't check it again
> + * unnecessarily
> + */
> + if (event->fd >= 0)
> + SAFE_CLOSE(event->fd);
> + event->fd = FAN_NOFD;
> + event->mask &= ~event_set[test_num];
> + /* No events left in current mask? Go for next event */
> + if (event->mask == 0) {
> + event = FAN_EVENT_NEXT(event, len);
> + }
> + test_num++;
> + }
> +
> + while (FAN_EVENT_OK(event, len)) {
> + tst_res(TFAIL,
> + "got unnecessary event: mask=%llx",
> + (unsigned long long)event->mask);
> + if (event->fd != FAN_NOFD)
> + SAFE_CLOSE(event->fd);
> + event = FAN_EVENT_NEXT(event, len);
> + }
> +
> + SAFE_CLOSE(fd_notify);
> + /* Flush out all pending dirty inodes and destructing marks */
> + mount_cycle();
> +}
> +
> +static void setup(void)
> +{
> + SAFE_TOUCH(TEST_FILE, 0666, NULL);
> +
> + REQUIRE_MARK_TYPE_SUPPORTED_BY_KERNEL(FAN_MARK_EVICTABLE);
> + REQUIRE_FANOTIFY_EVENTS_SUPPORTED_ON_FS(FAN_CLASS_NOTIF|FAN_REPORT_FID,
> + FAN_MARK_FILESYSTEM,
> + FAN_ATTRIB, ".");
> +
> + SAFE_FILE_SCANF(CACHE_PRESSURE_FILE, "%d", &old_cache_pressure);
> + /* Set high priority for evicting inodes */
> + SAFE_FILE_PRINTF(CACHE_PRESSURE_FILE, "500");
> +}
> +
> +static void cleanup(void)
> +{
> + if (fd_notify > 0)
> + SAFE_CLOSE(fd_notify);
> +
> + SAFE_FILE_PRINTF(CACHE_PRESSURE_FILE, "%d", old_cache_pressure);
> +}
> +
> +static struct tst_test test = {
> + .test_all = test_fanotify,
> + .setup = setup,
> + .cleanup = cleanup,
> + .needs_root = 1,
> + .mount_device = 1,
> + .mntpoint = MOUNT_PATH,
> + /* Shrinkers on other fs do not work reliably enough to guarantee mark eviction on drop_caches */
> + .dev_fs_type = "ext2",
> +};
> +
> +#else
> + TST_TEST_TCONF("system doesn't have required fanotify support");
> +#endif
> --
> 2.25.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
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