static int unionfs_chown(const char *path, uid_t uid, gid_t gid) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = lchown(p, uid, gid);
if (res == -1) RETURN(-errno);
RETURN(0);
}
static int unionfs_chmod(const char *path, mode_t mode) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = chmod(p, mode);
if (res == -1) RETURN(-errno);
RETURN(0);
}
static int unionfs_setxattr(const char *path, const char *name, const char *value, size_t size, int flags) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = lsetxattr(p, name, value, size, flags);
if (res == -1) RETURN(-errno);
RETURN(res);
}
static int unionfs_truncate(const char *path, off_t size) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = truncate(p, size);
if (res == -1) RETURN(-errno);
RETURN(0);
}
static int unionfs_removexattr(const char *path, const char *name) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = lremovexattr(p, name);
if (res == -1) RETURN(-errno);
RETURN(res);
}
static int unionfs_utimens(const char *path, const struct timespec ts[2]) {
DBG("%s\n", path);
if (uopt.stats_enabled && strcmp(path, STATS_FILENAME) == 0) RETURN(0);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
int res = utimensat(0, p, ts, AT_SYMLINK_NOFOLLOW);
if (res == -1) RETURN(-errno);
RETURN(0);
}
static int unionfs_setxattr(const char *path, const char *name, const char *value, size_t size, int flags, uint32_t position) {
#else
static int unionfs_setxattr(const char *path, const char *name, const char *value, size_t size, int flags) {
#endif
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
#if __APPLE__
int res = setxattr(p, name, value, size, position, flags | XATTR_NOFOLLOW);
#else
int res = lsetxattr(p, name, value, size, flags);
#endif
if (res == -1) RETURN(-errno);
RETURN(res);
}
static int unionfs_link(const char *from, const char *to) {
DBG("from %s to %s\n", from, to);
// hardlinks do not work across different filesystems so we need a copy of from first
int i = find_rw_branch_cow(from);
if (i == -1) RETURN(-errno);
int j = __find_rw_branch_cutlast(to, i);
if (j == -1) RETURN(-errno);
DBG("from branch: %d to branch: %d\n", i, j);
char f[PATHLEN_MAX], t[PATHLEN_MAX];
if (BUILD_PATH(f, uopt.branches[i].path, from)) RETURN(-ENAMETOOLONG);
if (BUILD_PATH(t, uopt.branches[j].path, to)) RETURN(-ENAMETOOLONG);
int res = link(f, t);
if (res == -1) RETURN(-errno);
// no need for set_owner(), since owner and permissions are copied over by link()
remove_hidden(to, i); // remove hide file (if any)
RETURN(0);
}
static int unionfs_utimens(const char *path, const struct timespec ts[2]) {
DBG("%s\n", path);
int i = find_rw_branch_cow(path);
if (i == -1) RETURN(-errno);
char p[PATHLEN_MAX];
if (BUILD_PATH(p, uopt.branches[i].path, path)) RETURN(-ENAMETOOLONG);
#ifdef UNIONFS_HAVE_AT
int res = utimensat(0, p, ts, AT_SYMLINK_NOFOLLOW);
#else
struct timeval tv[2];
tv[0].tv_sec = ts[0].tv_sec;
tv[0].tv_usec = ts[0].tv_nsec / 1000;
tv[1].tv_sec = ts[1].tv_sec;
tv[1].tv_usec = ts[1].tv_nsec / 1000;
int res = utimes(p, tv);
#endif
if (res == -1) RETURN(-errno);
RETURN(0);
}
/**
* unionfs rename function
* TODO: If we rename a directory on a read-only branch, we need to copy over
* all files to the renamed directory on the read-write branch.
*/
static int unionfs_rename(const char *from, const char *to) {
DBG("from %s to %s\n", from, to);
bool is_dir = false; // is 'from' a file or directory
int j = find_rw_branch_cutlast(to);
if (j == -1) RETURN(-errno);
int i = find_rorw_branch(from);
if (i == -1) RETURN(-errno);
if (!uopt.branches[i].rw) {
i = find_rw_branch_cow(from);
if (i == -1) RETURN(-errno);
}
if (i != j) {
USYSLOG(LOG_ERR, "%s: from and to are on different writable branches %d vs %d, which"
"is not supported yet.\n", __func__, i, j);
RETURN(-EXDEV);
}
char f[PATHLEN_MAX], t[PATHLEN_MAX];
if (BUILD_PATH(f, uopt.branches[i].path, from)) RETURN(-ENAMETOOLONG);
if (BUILD_PATH(t, uopt.branches[i].path, to)) RETURN(-ENAMETOOLONG);
filetype_t ftype = path_is_dir(f);
if (ftype == NOT_EXISTING)
RETURN(-ENOENT);
else if (ftype == IS_DIR)
is_dir = true;
int res;
if (!uopt.branches[i].rw) {
// since original file is on a read-only branch, we copied the from file to a writable branch,
// but since we will rename from, we also need to hide the from file on the read-only branch
if (is_dir)
res = hide_dir(from, i);
else
res = hide_file(from, i);
if (res) RETURN(-errno);
}
res = rename(f, t);
if (res == -1) {
int err = errno; // unlink() might overwrite errno
// if from was on a read-only branch we copied it, but now rename failed so we need to delete it
if (!uopt.branches[i].rw) {
if (unlink(f))
USYSLOG(LOG_ERR, "%s: cow of %s succeeded, but rename() failed and now "
"also unlink() failed\n", __func__, from);
if (remove_hidden(from, i))
USYSLOG(LOG_ERR, "%s: cow of %s succeeded, but rename() failed and now "
"also removing the whiteout failed\n", __func__, from);
}
RETURN(-err);
}
if (uopt.branches[i].rw) {
// A lower branch still *might* have a file called 'from', we need to delete this.
// We only need to do this if we have been on a rw-branch, since we created
// a whiteout for read-only branches anyway.
if (is_dir)
maybe_whiteout(from, i, WHITEOUT_DIR);
else
maybe_whiteout(from, i, WHITEOUT_FILE);
}
remove_hidden(to, i); // remove hide file (if any)
RETURN(0);
}
