diff options
author | Harald Hoyer <harald@redhat.com> | 2015-02-20 13:25:42 +0100 |
---|---|---|
committer | Lennart Poettering <lennart@poettering.net> | 2015-03-10 17:46:20 +0100 |
commit | 27cc6f166bdebc0e698fb692993b801db2618866 (patch) | |
tree | cff65e348f319d89b581414f433c3f605ac6ffc2 /src | |
parent | 918315e457ca36cab94ff3b6060e143968c99ace (diff) | |
download | systemd-27cc6f166bdebc0e698fb692993b801db2618866.tar.gz |
path-util: fix path_is_mount_point() for symlinks
path_is_mount_point() compares the mount_id of a directory and the
mount_id of the parent directory. When following symlinks, the function
to get the parent directory does not take the symlink into account.
/bin -> /usr/bin with /usr being a mountpoint:
mount_id of /bin with AT_SYMLINK_FOLLOW != mount_id of /
Diffstat (limited to 'src')
-rw-r--r-- | src/shared/path-util.c | 30 |
1 files changed, 13 insertions, 17 deletions
diff --git a/src/shared/path-util.c b/src/shared/path-util.c index 12d1ec321f..cdc61b1a79 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -457,9 +457,9 @@ int path_is_mount_point(const char *t, bool allow_symlink) { union file_handle_union h = FILE_HANDLE_INIT; int mount_id = -1, mount_id_parent = -1; - _cleanup_free_ char *parent = NULL; struct stat a, b; int r; + _cleanup_close_ int fd = -1; bool nosupp = false; /* We are not actually interested in the file handles, but @@ -469,7 +469,15 @@ int path_is_mount_point(const char *t, bool allow_symlink) { if (path_equal(t, "/")) return 1; - r = name_to_handle_at(AT_FDCWD, t, &h.handle, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); + fd = openat(AT_FDCWD, t, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|(allow_symlink ? 0 : O_PATH)); + if (fd < 0) { + if (errno == ENOENT) + return 0; + + return -errno; + } + + r = name_to_handle_at(fd, "", &h.handle, &mount_id, AT_EMPTY_PATH); if (r < 0) { if (errno == ENOSYS) /* This kernel does not support name_to_handle_at() @@ -486,12 +494,9 @@ int path_is_mount_point(const char *t, bool allow_symlink) { return -errno; } - r = path_get_parent(t, &parent); - if (r < 0) - return r; h.handle.handle_bytes = MAX_HANDLE_SZ; - r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, AT_SYMLINK_FOLLOW); + r = name_to_handle_at(fd, "..", &h.handle, &mount_id_parent, 0); if (r < 0) if (errno == EOPNOTSUPP) if (nosupp) @@ -510,10 +515,7 @@ int path_is_mount_point(const char *t, bool allow_symlink) { return mount_id != mount_id_parent; fallback: - if (allow_symlink) - r = stat(t, &a); - else - r = lstat(t, &a); + r = fstatat(fd, "", &a, AT_EMPTY_PATH); if (r < 0) { if (errno == ENOENT) @@ -522,14 +524,8 @@ fallback: return -errno; } - free(parent); - parent = NULL; - - r = path_get_parent(t, &parent); - if (r < 0) - return r; - r = stat(parent, &b); + r = fstatat(fd, "..", &b, 0); if (r < 0) return -errno; |