-/*
- * locate_fd finds a free file descriptor in the open_fds fdset,
- * expanding the fd arrays if necessary. Must be called with the
- * file_lock held for write.
- */
-
-static int locate_fd(unsigned int orig_start, int cloexec)
-{
- struct files_struct *files = current->files;
- unsigned int newfd;
- unsigned int start;
- int error;
- struct fdtable *fdt;
-
- spin_lock(&files->file_lock);
-repeat:
- fdt = files_fdtable(files);
- /*
- * Someone might have closed fd's in the range
- * orig_start..fdt->next_fd
- */
- start = orig_start;
- if (start < files->next_fd)
- start = files->next_fd;
-
- newfd = start;
- if (start < fdt->max_fds)
- newfd = find_next_zero_bit(fdt->open_fds->fds_bits,
- fdt->max_fds, start);
-
- error = expand_files(files, newfd);
- if (error < 0)
- goto out;
-
- /*
- * If we needed to expand the fs array we
- * might have blocked - try again.
- */
- if (error)
- goto repeat;
-
- if (start <= files->next_fd)
- files->next_fd = newfd + 1;
-
- FD_SET(newfd, fdt->open_fds);
- if (cloexec)
- FD_SET(newfd, fdt->close_on_exec);
- else
- FD_CLR(newfd, fdt->close_on_exec);
- error = newfd;
-
-out:
- spin_unlock(&files->file_lock);
- return error;
-}
-
-static int dupfd(struct file *file, unsigned int start, int cloexec)
-{
- int fd = locate_fd(start, cloexec);
- if (fd >= 0)
- fd_install(fd, file);
- else
- fput(file);
-
- return fd;
-}
-