X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fbtrfs-util.c;h=b34ac8b15a80260c13cef09701bf1673d79d84df;hb=07a0d22f9ec5a0cac2385b73dc08b12a811cead8;hp=254483c31a3ce5649fc0d722456c448a5461d450;hpb=1c7dd82563ff2e71a067aea20d2acb2d0553644b;p=elogind.git

diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c
index 254483c31..b34ac8b15 100644
--- a/src/shared/btrfs-util.c
+++ b/src/shared/btrfs-util.c
@@ -228,14 +228,18 @@ int btrfs_subvol_remove(const char *path) {
         return 0;
 }
 
-int btrfs_subvol_set_read_only(const char *path, bool b) {
-        _cleanup_close_ int fd = -1;
+int btrfs_subvol_set_read_only_fd(int fd, bool b) {
         uint64_t flags, nflags;
+        struct stat st;
 
-        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
-        if (fd < 0)
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0)
                 return -errno;
 
+        if (!S_ISDIR(st.st_mode) || st.st_ino != 256)
+                return -EINVAL;
+
         if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0)
                 return -errno;
 
@@ -253,6 +257,16 @@ int btrfs_subvol_set_read_only(const char *path, bool b) {
         return 0;
 }
 
+int btrfs_subvol_set_read_only(const char *path, bool b) {
+        _cleanup_close_ int fd = -1;
+
+        fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+        if (fd < 0)
+                return -errno;
+
+        return btrfs_subvol_set_read_only_fd(fd, b);
+}
+
 int btrfs_subvol_get_read_only_fd(int fd) {
         uint64_t flags;