diff options
Diffstat (limited to 'src/shared/path-util.c')
| -rw-r--r-- | src/shared/path-util.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/src/shared/path-util.c b/src/shared/path-util.c index 7090989fcb..8be479cd7f 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -509,7 +509,7 @@ static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id return safe_atoi(p, mnt_id); } -int fd_is_mount_point(int fd) { +int fd_is_mount_point(int fd, const char *filename, int flags) { union file_handle_union h = FILE_HANDLE_INIT, h_parent = FILE_HANDLE_INIT; int mount_id = -1, mount_id_parent = -1; bool nosupp = false, check_st_dev = true; @@ -517,6 +517,7 @@ int fd_is_mount_point(int fd) { int r; assert(fd >= 0); + assert(filename); /* First we will try the name_to_handle_at() syscall, which * tells us the mount id and an opaque file "handle". It is @@ -541,7 +542,7 @@ int fd_is_mount_point(int fd) { * subvolumes have different st_dev, even though they aren't * real mounts of their own. */ - r = name_to_handle_at(fd, "", &h.handle, &mount_id, AT_EMPTY_PATH); + r = name_to_handle_at(fd, filename, &h.handle, &mount_id, flags); if (r < 0) { if (errno == ENOSYS) /* This kernel does not support name_to_handle_at() @@ -558,7 +559,7 @@ int fd_is_mount_point(int fd) { return -errno; } - r = name_to_handle_at(fd, "..", &h_parent.handle, &mount_id_parent, 0); + r = name_to_handle_at(fd, "", &h_parent.handle, &mount_id_parent, AT_EMPTY_PATH); if (r < 0) { if (errno == EOPNOTSUPP) { if (nosupp) @@ -593,13 +594,13 @@ int fd_is_mount_point(int fd) { return mount_id != mount_id_parent; fallback_fdinfo: - r = fd_fdinfo_mnt_id(fd, "", AT_EMPTY_PATH, &mount_id); + r = fd_fdinfo_mnt_id(fd, filename, flags, &mount_id); if (r == -EOPNOTSUPP) goto fallback_fstat; if (r < 0) return r; - r = fd_fdinfo_mnt_id(fd, "..", 0, &mount_id_parent); + r = fd_fdinfo_mnt_id(fd, "", AT_EMPTY_PATH, &mount_id_parent); if (r < 0) return r; @@ -615,10 +616,16 @@ fallback_fdinfo: check_st_dev = false; fallback_fstat: - if (fstatat(fd, "", &a, AT_EMPTY_PATH) < 0) + /* yay for fstatat() taking a different set of flags than the other + * _at() above */ + if (flags & AT_SYMLINK_FOLLOW) + flags &= ~AT_SYMLINK_FOLLOW; + else + flags |= AT_SYMLINK_NOFOLLOW; + if (fstatat(fd, filename, &a, flags) < 0) return -errno; - if (fstatat(fd, "..", &b, 0) < 0) + if (fstatat(fd, "", &b, AT_EMPTY_PATH) < 0) return -errno; /* A directory with same device and inode as its parent? Must @@ -632,17 +639,23 @@ fallback_fstat: int path_is_mount_point(const char *t, bool allow_symlink) { _cleanup_close_ int fd = -1; + _cleanup_free_ char *parent = NULL; + int r; assert(t); if (path_equal(t, "/")) return 1; - fd = openat(AT_FDCWD, t, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|(allow_symlink ? 0 : O_PATH)); + r = path_get_parent(t, &parent); + if (r < 0) + return r; + + fd = openat(AT_FDCWD, parent, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_PATH); if (fd < 0) return -errno; - return fd_is_mount_point(fd); + return fd_is_mount_point(fd, basename(t), (allow_symlink ? AT_SYMLINK_FOLLOW : 0)); } int path_is_read_only_fs(const char *path) { |