Btrfs-progs: make sure we are opening a file or dir with open_file_or_dir()

Previously, open_file_or_dir() will open block device successfully, however,
we should enhance such checks to make sure we are really opening a file or dir.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/utils.c b/utils.c
index c1c55db..9fd8710 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -1571,13 +1571,20 @@ int open_file_or_dir(const char *fname, DIR **dirstream)
        if (S_ISDIR(st.st_mode)) {
                *dirstream = opendir(fname);
                if (!*dirstream)
-                       return -2;
+                       return -1;
                fd = dirfd(*dirstream);
-       } else {
+       } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
                fd = open(fname, O_RDWR);
+       } else {
+               /*
+                * we set this on purpose, in case the caller output
+                * strerror(errno) as success
+                */
+               errno = EINVAL;
+               return -1;
        }
        if (fd < 0) {
-               fd = -3;
+               fd = -1;
                if (*dirstream)
                        closedir(*dirstream);
        }