Test for kernel and filesystem support for conenctable file handles.
With -N flag, encode connectable file handles and fail the test if the
kernel or filesystem do not support conenctable file handles.
Verify that decoding connectable file handles always results in a non
empty path of the fd.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
common/rc | 16 ++++++++++---
src/open_by_handle.c | 53 ++++++++++++++++++++++++++++++++++++--------
2 files changed, 57 insertions(+), 12 deletions(-)
diff --git a/common/rc b/common/rc
index 6592c835..6407b744 100644
--- a/common/rc
+++ b/common/rc
@@ -3829,8 +3829,14 @@ _require_freeze()
}
# Does NFS export work on this fs?
-_require_exportfs()
+_require_open_by_handle()
{
+ local what="NFS export"
+ local opts="$1"
+ if [ "$1" == "-N" ]; then
+ what="connectable file handles"
+ fi
+
_require_test_program "open_by_handle"
# virtiofs doesn't support open_by_handle_at(2) yet, though the syscall
@@ -3841,10 +3847,14 @@ _require_exportfs()
_notrun "$FSTYP doesn't support open_by_handle_at(2)"
mkdir -p "$TEST_DIR"/exportfs_test
- $here/src/open_by_handle -c "$TEST_DIR"/exportfs_test 2>&1 \
- || _notrun "$FSTYP does not support NFS export"
+ $here/src/open_by_handle $opts -c "$TEST_DIR"/exportfs_test 2>&1 \
+ || _notrun "$FSTYP does not support $what"
}
+_require_exportfs()
+{
+ _require_open_by_handle
+}
# Does shutdown work on this fs?
_require_scratch_shutdown()
diff --git a/src/open_by_handle.c b/src/open_by_handle.c
index a99cce4b..7b664201 100644
--- a/src/open_by_handle.c
+++ b/src/open_by_handle.c
@@ -96,6 +96,9 @@ Examples:
#ifndef AT_HANDLE_MNT_ID_UNIQUE
# define AT_HANDLE_MNT_ID_UNIQUE 0x001
#endif
+#ifndef AT_HANDLE_CONNECTABLE
+# define AT_HANDLE_CONNECTABLE 0x002
+#endif
#define MAXFILES 1024
@@ -121,6 +124,7 @@ void usage(void)
fprintf(stderr, "open_by_handle -d <test_dir> [N] - unlink test files and hardlinks, drop caches and try to open by handle\n");
fprintf(stderr, "open_by_handle -m <test_dir> [N] - rename test files, drop caches and try to open by handle\n");
fprintf(stderr, "open_by_handle -M <test_dir> [N] - do not silently skip the mount ID verifications\n");
+ fprintf(stderr, "open_by_handle -N <test_dir> [N] - encode connectable file handles\n");
fprintf(stderr, "open_by_handle -p <test_dir> - create/delete and try to open by handle also test_dir itself\n");
fprintf(stderr, "open_by_handle -i <handles_file> <test_dir> [N] - read test files handles from file and try to open by handle\n");
fprintf(stderr, "open_by_handle -o <handles_file> <test_dir> [N] - get file handles of test files and write handles to file\n");
@@ -130,14 +134,16 @@ void usage(void)
fprintf(stderr, "open_by_handle -C <feature> - check if <feature> is supported by the kernel.\n");
fprintf(stderr, " <feature> can be any of the following values:\n");
fprintf(stderr, " - AT_HANDLE_MNT_ID_UNIQUE\n");
+ fprintf(stderr, " - AT_HANDLE_CONNECTABLE\n");
exit(EXIT_FAILURE);
}
-static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
- int bufsz, bool force_check_mountid)
+static int do_name_to_handle_at(const char *fname, struct file_handle *fh, int bufsz,
+ bool force_check_mountid, bool connectable)
{
int ret;
int mntid_short;
+ int at_flags;
static bool skip_mntid, skip_mntid_unique;
@@ -181,18 +187,24 @@ static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
}
}
+ at_flags = connectable ? AT_HANDLE_CONNECTABLE : 0;
fh->handle_bytes = bufsz;
- ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, 0);
+ ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, at_flags);
if (bufsz < fh->handle_bytes) {
/* Query the filesystem required bufsz and the file handle */
if (ret != -1 || errno != EOVERFLOW) {
fprintf(stderr, "%s: unexpected result from name_to_handle_at: %d (%m)\n", fname, ret);
return EXIT_FAILURE;
}
- ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, 0);
+ ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, at_flags);
}
if (ret < 0) {
- fprintf(stderr, "%s: name_to_handle: %m\n", fname);
+ /* No filesystem support for encoding connectable file handles (e.g. overlayfs)? */
+ if (connectable)
+ fprintf(stderr, "%s: name_to_handle_at(AT_HANDLE_CONNECTABLE) not supported by %s\n",
+ fname, errno == EINVAL ? "kernel" : "filesystem");
+ else
+ fprintf(stderr, "%s: name_to_handle: %m\n", fname);
return EXIT_FAILURE;
}
@@ -245,8 +257,17 @@ static int check_feature(const char *feature)
return EXIT_FAILURE;
}
return 0;
+ } else if (!strcmp(feature, "AT_HANDLE_CONNECTABLE")) {
+ int ret = name_to_handle_at(AT_FDCWD, ".", NULL, NULL, AT_HANDLE_CONNECTABLE);
+ /* If AT_HANDLE_CONNECTABLE is supported, we get EFAULT. */
+ if (ret < 0 && errno == EINVAL) {
+ fprintf(stderr, "name_to_handle_at(AT_HANDLE_CONNECTABLE) not supported by running kernel\n");
+ return EXIT_FAILURE;
+ }
+ return 0;
}
+
fprintf(stderr, "unknown feature name '%s'\n", feature);
return EXIT_FAILURE;
}
@@ -270,13 +291,13 @@ int main(int argc, char **argv)
int create = 0, delete = 0, nlink = 1, move = 0;
int rd = 0, wr = 0, wrafter = 0, parent = 0;
int keepopen = 0, drop_caches = 1, sleep_loop = 0;
- int force_check_mountid = 0;
+ bool force_check_mountid = 0, connectable = 0;
int bufsz = MAX_HANDLE_SZ;
if (argc < 2)
usage();
- while ((c = getopt(argc, argv, "cC:ludmMrwapknhi:o:sz")) != -1) {
+ while ((c = getopt(argc, argv, "cC:ludmMNrwapknhi:o:sz")) != -1) {
switch (c) {
case 'c':
create = 1;
@@ -313,6 +334,9 @@ int main(int argc, char **argv)
case 'M':
force_check_mountid = 1;
break;
+ case 'N':
+ connectable = 1;
+ break;
case 'p':
parent = 1;
break;
@@ -445,7 +469,8 @@ int main(int argc, char **argv)
return EXIT_FAILURE;
}
} else {
- ret = do_name_to_handle_at(fname, &handle[i].fh, bufsz, force_check_mountid);
+ ret = do_name_to_handle_at(fname, &handle[i].fh, bufsz,
+ force_check_mountid, connectable);
if (ret)
return EXIT_FAILURE;
}
@@ -475,7 +500,8 @@ int main(int argc, char **argv)
return EXIT_FAILURE;
}
} else {
- ret = do_name_to_handle_at(test_dir, &dir_handle.fh, bufsz, force_check_mountid);
+ ret = do_name_to_handle_at(test_dir, &dir_handle.fh, bufsz,
+ force_check_mountid, connectable);
if (ret)
return EXIT_FAILURE;
}
@@ -589,6 +615,15 @@ int main(int argc, char **argv)
errno = 0;
fd = open_by_handle_at(mount_fd, &handle[i].fh, wrafter ? O_RDWR : O_RDONLY);
if ((nlink || keepopen) && fd >= 0) {
+ char linkname[PATH_MAX];
+ char procname[64];
+ sprintf(procname, "/proc/self/fd/%i", fd);
+ int n = readlink(procname, linkname, PATH_MAX);
+
+ /* check that fd is "connected" - that is has a non empty path */
+ if (connectable && n <= 1) {
+ printf("open_by_handle(%s) returned a disconnected fd!\n", fname);
+ }
if (rd) {
char buf[4] = {0};
int size = read(fd, buf, 4);
--
2.34.1
