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 | 58 +++++++++++++++++--
1 file changed, 52 insertions(+), 6 deletions(-)
diff --git a/testcases/kernel/syscalls/readahead/readahead02.c b/testcases/kernel/syscalls/readahead/readahead02.c
index 158bfc955..ea73f8566 100644
--- a/testcases/kernel/syscalls/readahead/readahead02.c
+++ b/testcases/kernel/syscalls/readahead/readahead02.c
@@ -52,6 +52,46 @@ static struct tst_option options[] = {
{NULL, NULL, NULL}
};
+/*
+ * Check this system has fadvise64 syscall which is used in posix_fadvise.
+ * This is the only system configuration supported by the posix_fadvise tests,
+ * so use posix_fadvise in this test only with this system configuration.
+ */
+#ifdef __NR_fadvise64
+#define READAHEAD_WITH_FADVISE
+#else
+#if defined(_FILE_OFFSET_BITS) && (_FILE_OFFSET_BITS == 64)
+#define READAHEAD_WITH_FADVISE
+#endif
+#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 },
+#ifdef READAHEAD_WITH_FADVISE
+ { "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) {
@@ -139,7 +179,6 @@ static void create_testfile(int use_overlay)
free(tmp);
}
-
/* 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.
@@ -169,7 +208,7 @@ 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;
@@ -231,21 +270,28 @@ 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_high, 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 (use_overlay && !ovl_mounted) {
+ if (tc->use_overlay && !ovl_mounted) {
tst_res(TCONF,
"overlayfs is not configured in this kernel.");
return;
}
- create_testfile(use_overlay);
+ create_testfile(tc->use_overlay);
+
+ /* 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);
@@ -361,7 +407,7 @@ 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
