[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


More information about the ltp mailing list