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-rw-r--r--images/hostoverlaytest/test.c88
1 files changed, 0 insertions, 88 deletions
diff --git a/images/hostoverlaytest/test.c b/images/hostoverlaytest/test.c
deleted file mode 100644
index 088f90746..000000000
--- a/images/hostoverlaytest/test.c
+++ /dev/null
@@ -1,88 +0,0 @@
-#include <err.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <unistd.h>
-
-int main(int argc, char** argv) {
- const char kTestFilePath[] = "testfile.txt";
- const char kOldFileData[] = "old data\n";
- const char kNewFileData[] = "new data\n";
- const size_t kPageSize = sysconf(_SC_PAGE_SIZE);
-
- // Open a file that already exists in a host overlayfs lower layer.
- const int fd_rdonly = open(kTestFilePath, O_RDONLY);
- if (fd_rdonly < 0) {
- err(1, "open(%s, O_RDONLY)", kTestFilePath);
- }
-
- // Check that the file's initial contents are what we expect when read via
- // syscall.
- char oldbuf[sizeof(kOldFileData)] = {};
- ssize_t n = pread(fd_rdonly, oldbuf, sizeof(oldbuf), 0);
- if (n < 0) {
- err(1, "initial pread");
- }
- if (n != strlen(kOldFileData)) {
- errx(1, "short initial pread (%ld/%lu bytes)", n, strlen(kOldFileData));
- }
- if (strcmp(oldbuf, kOldFileData) != 0) {
- errx(1, "initial pread returned wrong data: %s", oldbuf);
- }
-
- // Check that the file's initial contents are what we expect when read via
- // memory mapping.
- void* page = mmap(NULL, kPageSize, PROT_READ, MAP_SHARED, fd_rdonly, 0);
- if (page == MAP_FAILED) {
- err(1, "mmap");
- }
- if (strcmp(page, kOldFileData) != 0) {
- errx(1, "mapping contains wrong initial data: %s", (const char*)page);
- }
-
- // Open the same file writably, causing host overlayfs to copy it up, and
- // replace its contents.
- const int fd_rdwr = open(kTestFilePath, O_RDWR);
- if (fd_rdwr < 0) {
- err(1, "open(%s, O_RDWR)", kTestFilePath);
- }
- n = write(fd_rdwr, kNewFileData, strlen(kNewFileData));
- if (n < 0) {
- err(1, "write");
- }
- if (n != strlen(kNewFileData)) {
- errx(1, "short write (%ld/%lu bytes)", n, strlen(kNewFileData));
- }
- if (ftruncate(fd_rdwr, strlen(kNewFileData)) < 0) {
- err(1, "truncate");
- }
-
- int failed = 0;
-
- // Check that syscalls on the old FD return updated contents. (Before Linux
- // 4.18, this requires that runsc use a post-copy-up FD to service the read.)
- char newbuf[sizeof(kNewFileData)] = {};
- n = pread(fd_rdonly, newbuf, sizeof(newbuf), 0);
- if (n < 0) {
- err(1, "final pread");
- }
- if (n != strlen(kNewFileData)) {
- warnx("short final pread (%ld/%lu bytes)", n, strlen(kNewFileData));
- failed = 1;
- } else if (strcmp(newbuf, kNewFileData) != 0) {
- warnx("final pread returned wrong data: %s", newbuf);
- failed = 1;
- }
-
- // Check that the memory mapping of the old FD has been updated. (Linux
- // overlayfs does not do this, so regardless of kernel version this requires
- // that runsc replace existing memory mappings with mappings of a
- // post-copy-up FD.)
- if (strcmp(page, kNewFileData) != 0) {
- warnx("mapping contains wrong final data: %s", (const char*)page);
- failed = 1;
- }
-
- return failed;
-}