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authorLinus Torvalds2019-05-07 20:17:51 -0700
committerLinus Torvalds2019-05-07 20:17:51 -0700
commit400913252d09f9cfb8cce33daee43167921fc343 (patch)
tree54a85b9df82ca67d1d19903a1cd5331f8f69065d /samples
parentd27fb65bc2389621040e5107baedb94b4cccf641 (diff)
parentf1b5618e013af28b3c78daf424436a79674423c0 (diff)
Merge branch 'work.mount-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull mount ABI updates from Al Viro: "The syscalls themselves, finally. That's not all there is to that stuff, but switching individual filesystems to new methods is fortunately independent from everything else, so e.g. NFS series can go through NFS tree, etc. As those conversions get done, we'll be finally able to get rid of a bunch of duplication in fs/super.c introduced in the beginning of the entire thing. I expect that to be finished in the next window..." * 'work.mount-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Add a sample program for the new mount API vfs: syscall: Add fspick() to select a superblock for reconfiguration vfs: syscall: Add fsmount() to create a mount for a superblock vfs: syscall: Add fsconfig() for configuring and managing a context vfs: Implement logging through fs_context vfs: syscall: Add fsopen() to prepare for superblock creation Make anon_inodes unconditional teach move_mount(2) to work with OPEN_TREE_CLONE vfs: syscall: Add move_mount(2) to move mounts around vfs: syscall: Add open_tree(2) to reference or clone a mount
Diffstat (limited to 'samples')
-rw-r--r--samples/Kconfig9
-rw-r--r--samples/Makefile2
-rw-r--r--samples/vfs/Makefile (renamed from samples/statx/Makefile)5
-rw-r--r--samples/vfs/test-fsmount.c133
-rw-r--r--samples/vfs/test-statx.c (renamed from samples/statx/test-statx.c)11
5 files changed, 153 insertions, 7 deletions
diff --git a/samples/Kconfig b/samples/Kconfig
index d19754ccad08..30a89425009c 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -154,10 +154,11 @@ config SAMPLE_ANDROID_BINDERFS
Builds a sample program to illustrate the use of the Android binderfs
filesystem.
-config SAMPLE_STATX
- bool "Build example extended-stat using code"
- depends on BROKEN
+config SAMPLE_VFS
+ bool "Build example programs that use new VFS system calls"
help
- Build example userspace program to use the new extended-stat syscall.
+ Build example userspace programs that use new VFS system calls such
+ as mount API and statx(). Note that this is restricted to the x86
+ arch whilst it accesses system calls that aren't yet in all arches.
endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index fadadb1c3b05..2484cc262d3e 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -3,4 +3,4 @@
obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \
hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
configfs/ connector/ v4l/ trace_printk/ \
- vfio-mdev/ statx/ qmi/ binderfs/ pidfd/
+ vfio-mdev/ vfs/ qmi/ binderfs/ pidfd/
diff --git a/samples/statx/Makefile b/samples/vfs/Makefile
index 59df7c25a9d1..4ac9690fb3c4 100644
--- a/samples/statx/Makefile
+++ b/samples/vfs/Makefile
@@ -1,7 +1,10 @@
# List of programs to build
-hostprogs-$(CONFIG_SAMPLE_STATX) := test-statx
+hostprogs-$(CONFIG_SAMPLE_VFS) := \
+ test-fsmount \
+ test-statx
# Tell kbuild to always build the programs
always := $(hostprogs-y)
+HOSTCFLAGS_test-fsmount.o += -I$(objtree)/usr/include
HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include
diff --git a/samples/vfs/test-fsmount.c b/samples/vfs/test-fsmount.c
new file mode 100644
index 000000000000..266d72b3dce4
--- /dev/null
+++ b/samples/vfs/test-fsmount.c
@@ -0,0 +1,133 @@
+/* fd-based mount test.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <linux/mount.h>
+#include <linux/unistd.h>
+
+#define E(x) do { if ((x) == -1) { perror(#x); exit(1); } } while(0)
+
+static void check_messages(int fd)
+{
+ char buf[4096];
+ int err, n;
+
+ err = errno;
+
+ for (;;) {
+ n = read(fd, buf, sizeof(buf));
+ if (n < 0)
+ break;
+ n -= 2;
+
+ switch (buf[0]) {
+ case 'e':
+ fprintf(stderr, "Error: %*.*s\n", n, n, buf + 2);
+ break;
+ case 'w':
+ fprintf(stderr, "Warning: %*.*s\n", n, n, buf + 2);
+ break;
+ case 'i':
+ fprintf(stderr, "Info: %*.*s\n", n, n, buf + 2);
+ break;
+ }
+ }
+
+ errno = err;
+}
+
+static __attribute__((noreturn))
+void mount_error(int fd, const char *s)
+{
+ check_messages(fd);
+ fprintf(stderr, "%s: %m\n", s);
+ exit(1);
+}
+
+/* Hope -1 isn't a syscall */
+#ifndef __NR_fsopen
+#define __NR_fsopen -1
+#endif
+#ifndef __NR_fsmount
+#define __NR_fsmount -1
+#endif
+#ifndef __NR_fsconfig
+#define __NR_fsconfig -1
+#endif
+#ifndef __NR_move_mount
+#define __NR_move_mount -1
+#endif
+
+
+static inline int fsopen(const char *fs_name, unsigned int flags)
+{
+ return syscall(__NR_fsopen, fs_name, flags);
+}
+
+static inline int fsmount(int fsfd, unsigned int flags, unsigned int ms_flags)
+{
+ return syscall(__NR_fsmount, fsfd, flags, ms_flags);
+}
+
+static inline int fsconfig(int fsfd, unsigned int cmd,
+ const char *key, const void *val, int aux)
+{
+ return syscall(__NR_fsconfig, fsfd, cmd, key, val, aux);
+}
+
+static inline int move_mount(int from_dfd, const char *from_pathname,
+ int to_dfd, const char *to_pathname,
+ unsigned int flags)
+{
+ return syscall(__NR_move_mount,
+ from_dfd, from_pathname,
+ to_dfd, to_pathname, flags);
+}
+
+#define E_fsconfig(fd, cmd, key, val, aux) \
+ do { \
+ if (fsconfig(fd, cmd, key, val, aux) == -1) \
+ mount_error(fd, key ?: "create"); \
+ } while (0)
+
+int main(int argc, char *argv[])
+{
+ int fsfd, mfd;
+
+ /* Mount a publically available AFS filesystem */
+ fsfd = fsopen("afs", 0);
+ if (fsfd == -1) {
+ perror("fsopen");
+ exit(1);
+ }
+
+ E_fsconfig(fsfd, FSCONFIG_SET_STRING, "source", "#grand.central.org:root.cell.", 0);
+ E_fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
+
+ mfd = fsmount(fsfd, 0, MOUNT_ATTR_RDONLY);
+ if (mfd < 0)
+ mount_error(fsfd, "fsmount");
+ E(close(fsfd));
+
+ if (move_mount(mfd, "", AT_FDCWD, "/mnt", MOVE_MOUNT_F_EMPTY_PATH) < 0) {
+ perror("move_mount");
+ exit(1);
+ }
+
+ E(close(mfd));
+ exit(0);
+}
diff --git a/samples/statx/test-statx.c b/samples/vfs/test-statx.c
index d4d77b09412c..e91f918e84c4 100644
--- a/samples/statx/test-statx.c
+++ b/samples/vfs/test-statx.c
@@ -25,13 +25,21 @@
#include <sys/types.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
+#define statx foo
+#define statx_timestamp foo_timestamp
#include <sys/stat.h>
+#undef statx
+#undef statx_timestamp
#define AT_STATX_SYNC_TYPE 0x6000
#define AT_STATX_SYNC_AS_STAT 0x0000
#define AT_STATX_FORCE_SYNC 0x2000
#define AT_STATX_DONT_SYNC 0x4000
+#ifndef __NR_statx
+#define __NR_statx -1
+#endif
+
static __attribute__((unused))
ssize_t statx(int dfd, const char *filename, unsigned flags,
unsigned int mask, struct statx *buffer)
@@ -157,7 +165,8 @@ static void dump_statx(struct statx *stx)
"?dai?c??" /* 7- 0 0x00000000-000000ff */
;
- printf("Attributes: %016llx (", stx->stx_attributes);
+ printf("Attributes: %016llx (",
+ (unsigned long long)stx->stx_attributes);
for (byte = 64 - 8; byte >= 0; byte -= 8) {
bits = stx->stx_attributes >> byte;
mbits = stx->stx_attributes_mask >> byte;