src/cloner: check filesystem type

Limit clone requests to Btrfs only for the moment.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/src/cloner.c b/src/cloner.c
index ccc2354c26c381e14c8d44e77404a4f0084b4beb..6fb40fa01d27e58d015c036b8cd9b682148cc781 100644 (file)
--- a/src/cloner.c
+++ b/src/cloner.c
@@ -22,6 +22,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>

+#include <sys/vfs.h>

 #include <stdint.h>
 #include <stdbool.h>
 #include <fcntl.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <fcntl.h>


@@ -30,6 +31,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>

+#include <linux/magic.h>

 #ifdef HAVE_BTRFS_IOCTL_H
 #include <btrfs/ioctl.h>
 #else
 #ifdef HAVE_BTRFS_IOCTL_H
 #include <btrfs/ioctl.h>
 #else


@@ -47,6 +49,10 @@ struct btrfs_ioctl_clone_range_args {
                                   struct btrfs_ioctl_clone_range_args)
 #endif
 
                                   struct btrfs_ioctl_clone_range_args)
 #endif
 

+#ifndef BTRFS_SUPER_MAGIC
+#define BTRFS_SUPER_MAGIC    0x9123683E
+#endif
+

 static void
 usage(char *name, const char *msg)
 {
 static void
 usage(char *name, const char *msg)
 {


@@ -89,6 +95,41 @@ clone_file_range(int src_fd, int dst_fd, uint64_t src_off, uint64_t dst_off,
        return ret;
 }
 
        return ret;
 }
 

+static int
+cloner_check_fs_support(int src_fd, int dest_fd, unsigned int *fs_type)
+{
+       int ret;
+       struct statfs sfs;
+
+       ret = fstatfs(src_fd, &sfs);
+       if (ret != 0) {
+               printf("failed to stat source FS\n");
+               return errno;
+       }
+
+       if (sfs.f_type != BTRFS_SUPER_MAGIC) {
+               printf("unsupported source FS 0x%x\n",
+                      (unsigned int)sfs.f_type);
+               return ENOTSUP;
+       }
+
+       *fs_type = (unsigned int)sfs.f_type;
+
+       ret = fstatfs(dest_fd, &sfs);
+       if (ret != 0) {
+               printf("failed to stat destination FS\n");
+               return errno;
+       }
+
+       if (sfs.f_type != *fs_type) {
+               printf("dest FS type 0x%x does not match source 0x%x\n",
+                      (unsigned int)sfs.f_type, *fs_type);
+               return ENOTSUP;
+       }
+
+       return 0;
+}
+

 int
 main(int argc, char **argv)
 {
 int
 main(int argc, char **argv)
 {


@@ -102,6 +143,7 @@ main(int argc, char **argv)
        int dst_fd;
        int ret;
        int opt;
        int dst_fd;
        int ret;
        int opt;

+       unsigned int fs_type = 0;

 
        while ((opt = getopt(argc, argv, "s:d:l:")) != -1) {
                char *sval_end;
 
        while ((opt = getopt(argc, argv, "s:d:l:")) != -1) {
                char *sval_end;


@@ -162,6 +204,11 @@ main(int argc, char **argv)
                goto err_src_close;
        }
 
                goto err_src_close;
        }
 

+       ret = cloner_check_fs_support(src_fd, dst_fd, &fs_type);
+       if (ret != 0) {
+               goto err_dst_close;
+       }
+

        if (full_file) {
                ret = clone_file(src_fd, dst_fd);
        } else {
        if (full_file) {
                ret = clone_file(src_fd, dst_fd);
        } else {