----- Original Message -----
> The call to posix_fadvise(POSIX_FADV_WILLNEED) should have the same
> effect as the call to readahead() syscall.
>
> Repeat the test cases for local file and overlayfs file with
> posix_fadvise().
>
> The new test case is a regression test for kernel commit b833a3660394
> ("ovl: add ovl_fadvise()") which fixes a regression of fadvise() on
> an overlay file that was introduced by kernel commit 5b910bd615ba
> ("ovl: fix GPF in swapfile_activate of file from overlayfs over xfs").
>
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> .../kernel/syscalls/readahead/readahead02.c | 57 +++++++++++++++++--
> 1 file changed, 51 insertions(+), 6 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/readahead/readahead02.c
> b/testcases/kernel/syscalls/readahead/readahead02.c
> index 191116f62..9ebed359d 100644
> --- a/testcases/kernel/syscalls/readahead/readahead02.c
> +++ b/testcases/kernel/syscalls/readahead/readahead02.c
> @@ -51,6 +51,42 @@ static struct tst_option options[] = {
> {NULL, NULL, NULL}
> };
>
> +#ifndef _FILE_OFFSET_BITS
> +#define _FILE_OFFSET_BITS 32
> +#endif
I don't think we should be touching this.
> +
> +#ifndef __NR_fadvise64
> +#define __NR_fadvise64 0
> +#endif
> +
> +static struct tcase {
> + const char *tname;
> + int use_overlay;
> + int use_fadvise;
> +} tcases[] = {
> + { "readahead on file", 0, 0 },
> + { "readahead on overlayfs file", 1, 0 },
> +/* Check this system has fadvise64 system which is used in posix_fadvise. */
> +#if ((_FILE_OFFSET_BITS == 64) || (__NR_fadvise64 != 0))
Can you elaborate on this check? Why do we need to care
about _FILE_OFFSET_BITS?
> + { "POSIX_FADV_WILLNEED on file", 0, 1 },
> + { "POSIX_FADV_WILLNEED on overlayfs file", 1, 1 },
> +#endif
> +};
> +
> +static int fadvise_willneed(int fd, off_t offset, size_t len)
> +{
> + /* Should have the same effect as readahead() syscall */
> + return posix_fadvise(fd, offset, len, POSIX_FADV_WILLNEED);
> +}
> +
> +static int libc_readahead(int fd, off_t offset, size_t len)
> +{
> + return readahead(fd, offset, len);
> +}
> +
> +typedef int (*readahead_func_t)(int, off_t, size_t);
> +static readahead_func_t readahead_func = libc_readahead;
> +
> static int check_ret(long expected_ret)
> {
> if (expected_ret == TST_RET) {
> @@ -120,6 +156,9 @@ static int setup_overlay(void)
> {
> int ret;
>
> + if (ovl_mounted)
> + return 0;
> +
You could call it once from setup() and drop check above
and other call from create_testfile().
Regards,
Jan
> /* Setup an overlay mount with lower dir and file */
> SAFE_MKDIR(OVL_LOWER, 0755);
> SAFE_MKDIR(OVL_UPPER, 0755);
> @@ -139,7 +178,7 @@ static int setup_overlay(void)
> return 0;
> }
>
> -static int create_testfile(unsigned int use_overlay)
> +static int create_testfile(int use_overlay)
> {
> int fd;
> char *tmp;
> @@ -164,7 +203,6 @@ static int create_testfile(unsigned int use_overlay)
> return 0;
> }
>
> -
> /* read_testfile - mmap testfile and read every page.
> * This functions measures how many I/O and time it takes to fully
> * read contents of test file.
> @@ -194,7 +232,7 @@ static void read_testfile(int do_readahead, const char
> *fname, size_t fsize,
> if (do_readahead) {
> cached_start = get_cached_size();
> do {
> - TEST(readahead(fd, offset, fsize - offset));
> + TEST(readahead_func(fd, offset, fsize - offset));
> if (TST_RET != 0) {
> check_ret(0);
> break;
> @@ -256,17 +294,24 @@ static void read_testfile(int do_readahead, const char
> *fname, size_t fsize,
> SAFE_CLOSE(fd);
> }
>
> -static void test_readahead(unsigned int use_overlay)
> +static void test_readahead(unsigned int n)
> {
> unsigned long read_bytes, read_bytes_ra;
> long usec, usec_ra;
> unsigned long cached_max, cached_low, cached, cached_ra;
> char proc_io_fname[128];
> + struct tcase *tc = &tcases[n];
> +
> + tst_res(TINFO, "Test #%d: %s", n, tc->tname);
> +
> sprintf(proc_io_fname, "/proc/%u/io", getpid());
>
> - if (create_testfile(use_overlay) != 0)
> + if (create_testfile(tc->use_overlay) != 0)
> return;
>
> + /* Use either readahead() syscall or POSIX_FADV_WILLNEED */
> + readahead_func = tc->use_fadvise ? fadvise_willneed : libc_readahead;
> +
> /* find out how much can cache hold if we read whole file */
> read_testfile(0, testfile, testfile_size, &read_bytes, &usec, &cached);
> cached_max = get_cached_size();
> @@ -357,7 +402,7 @@ static struct tst_test test = {
> .cleanup = cleanup,
> .options = options,
> .test = test_readahead,
> - .tcnt = 2, /* Repeat with overlayfs */
> + .tcnt = ARRAY_SIZE(tcases),
> };
>
> #else /* __NR_readahead */
> --
> 2.17.1
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
