50  * space if any.  This does not copy the file pointers.  Called with the files
73  * clear the extra space.  Called with the files spinlock held for write.
150  * The files->file_lock should be held on entry, and will be held on exit.
152 static int expand_fdtable(struct files_struct *files, unsigned int nr)  in expand_fdtable()  argument
153 	__releases(files->file_lock)  in expand_fdtable()
154 	__acquires(files->file_lock)  in expand_fdtable()
158 	spin_unlock(&files->file_lock);  in expand_fdtable()
164 	if (atomic_read(&files->count) > 1)  in expand_fdtable()
167 	spin_lock(&files->file_lock);  in expand_fdtable()
178 	cur_fdt = files_fdtable(files);  in expand_fdtable()
181 	rcu_assign_pointer(files->fdt, new_fdt);  in expand_fdtable()
182 	if (cur_fdt != &files->fdtab)  in expand_fdtable()
190  * Expand files.
193  * Return <0 error code on error; 0 when nothing done; 1 when files were
195  * The files->file_lock should be held on entry, and will be held on exit.
197 static int expand_files(struct files_struct *files, unsigned int nr)  in expand_files()  argument
198 	__releases(files->file_lock)  in expand_files()
199 	__acquires(files->file_lock)  in expand_files()
205 	fdt = files_fdtable(files);  in expand_files()
215 	if (unlikely(files->resize_in_progress)) {  in expand_files()
216 		spin_unlock(&files->file_lock);  in expand_files()
218 		wait_event(files->resize_wait, !files->resize_in_progress);  in expand_files()
219 		spin_lock(&files->file_lock);  in expand_files()
224 	files->resize_in_progress = true;  in expand_files()
225 	expanded = expand_fdtable(files, nr);  in expand_files()
226 	files->resize_in_progress = false;  in expand_files()
228 	wake_up_all(&files->resize_wait);  in expand_files()
282  * Allocate a new files structure and copy contents from the
283  * passed in files structure.
359 			 * instantiated in the files array if a sibling thread  in dup_fd()
382 static struct fdtable *close_files(struct files_struct * files)  in close_files()  argument
387 	 * files structure.  in close_files()
389 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);  in close_files()
402 					filp_close(file, files);  in close_files()
416 	struct files_struct *files;  in get_files_struct()  local
419 	files = task->files;  in get_files_struct()
420 	if (files)  in get_files_struct()
421 		atomic_inc(&files->count);  in get_files_struct()
424 	return files;  in get_files_struct()
427 void put_files_struct(struct files_struct *files)  in put_files_struct()  argument
429 	if (atomic_dec_and_test(&files->count)) {  in put_files_struct()
430 		struct fdtable *fdt = close_files(files);  in put_files_struct()
433 		if (fdt != &files->fdtab)  in put_files_struct()
435 		kmem_cache_free(files_cachep, files);  in put_files_struct()
439 void reset_files_struct(struct files_struct *files)  in reset_files_struct()  argument
444 	old = tsk->files;  in reset_files_struct()
446 	tsk->files = files;  in reset_files_struct()
453 	struct files_struct * files = tsk->files;  in exit_files()  local
455 	if (files) {  in exit_files()
456 		io_uring_files_cancel(files);  in exit_files()
458 		tsk->files = NULL;  in exit_files()
460 		put_files_struct(files);  in exit_files()
495 int __alloc_fd(struct files_struct *files,  in __alloc_fd()  argument
502 	spin_lock(&files->file_lock);  in __alloc_fd()
504 	fdt = files_fdtable(files);  in __alloc_fd()
506 	if (fd < files->next_fd)  in __alloc_fd()
507 		fd = files->next_fd;  in __alloc_fd()
513 	 * N.B. For clone tasks sharing a files structure, this test  in __alloc_fd()
514 	 * will limit the total number of files that can be opened.  in __alloc_fd()
520 	error = expand_files(files, fd);  in __alloc_fd()
531 	if (start <= files->next_fd)  in __alloc_fd()
532 		files->next_fd = fd + 1;  in __alloc_fd()
549 	spin_unlock(&files->file_lock);  in __alloc_fd()
555 	return __alloc_fd(current->files, start, rlimit(RLIMIT_NOFILE), flags);  in alloc_fd()
560 	return __alloc_fd(current->files, 0, nofile, flags);  in __get_unused_fd_flags()
569 static void __put_unused_fd(struct files_struct *files, unsigned int fd)  in __put_unused_fd()  argument
571 	struct fdtable *fdt = files_fdtable(files);  in __put_unused_fd()
573 	if (fd < files->next_fd)  in __put_unused_fd()
574 		files->next_fd = fd;  in __put_unused_fd()
579 	struct files_struct *files = current->files;  in put_unused_fd()  local
580 	spin_lock(&files->file_lock);  in put_unused_fd()
581 	__put_unused_fd(files, fd);  in put_unused_fd()
582 	spin_unlock(&files->file_lock);  in put_unused_fd()
590  * The VFS is full of places where we drop the files lock between
601  * your throat.  'files' *MUST* be either current->files or obtained
607 void __fd_install(struct files_struct *files, unsigned int fd,  in __fd_install()  argument
614 	if (unlikely(files->resize_in_progress)) {  in __fd_install()
616 		spin_lock(&files->file_lock);  in __fd_install()
617 		fdt = files_fdtable(files);  in __fd_install()
620 		spin_unlock(&files->file_lock);  in __fd_install()
625 	fdt = rcu_dereference_sched(files->fdt);  in __fd_install()
637 	__fd_install(current->files, fd, file);  in fd_install()
642 static struct file *pick_file(struct files_struct *files, unsigned fd)  in pick_file()  argument
647 	spin_lock(&files->file_lock);  in pick_file()
648 	fdt = files_fdtable(files);  in pick_file()
655 	__put_unused_fd(files, fd);  in pick_file()
658 	spin_unlock(&files->file_lock);  in pick_file()
665 int __close_fd(struct files_struct *files, unsigned fd)  in __close_fd()  argument
669 	file = pick_file(files, fd);  in __close_fd()
673 	return filp_close(file, files);  in __close_fd()
690 	struct files_struct *cur_fds = me->files, *fds = NULL;  in __close_range()
743 		 * We're done closing the files we were supposed to. Time to install  in __close_range()
747 		me->files = cur_fds;  in __close_range()
762 	struct files_struct *files = current->files;  in __close_fd_get_file()  local
766 	spin_lock(&files->file_lock);  in __close_fd_get_file()
767 	fdt = files_fdtable(files);  in __close_fd_get_file()
774 	__put_unused_fd(files, fd);  in __close_fd_get_file()
775 	spin_unlock(&files->file_lock);  in __close_fd_get_file()
781 	spin_unlock(&files->file_lock);  in __close_fd_get_file()
786 void do_close_on_exec(struct files_struct *files)  in do_close_on_exec()  argument
792 	spin_lock(&files->file_lock);  in do_close_on_exec()
796 		fdt = files_fdtable(files);  in do_close_on_exec()
811 			__put_unused_fd(files, fd);  in do_close_on_exec()
812 			spin_unlock(&files->file_lock);  in do_close_on_exec()
813 			filp_close(file, files);  in do_close_on_exec()
815 			spin_lock(&files->file_lock);  in do_close_on_exec()
819 	spin_unlock(&files->file_lock);  in do_close_on_exec()
822 static struct file *__fget_files(struct files_struct *files, unsigned int fd,  in __fget_files()  argument
829 	file = fcheck_files(files, fd);  in __fget_files()
848 	return __fget_files(current->files, fd, mask, refs);  in __fget()
873 	if (task->files)  in fget_task()
874 		file = __fget_files(task->files, fd, 0, 1);  in fget_task()
898 	struct files_struct *files = current->files;  in __fget_light()  local
901 	if (atomic_read(&files->count) == 1) {  in __fget_light()
902 		file = __fcheck_files(files, fd);  in __fget_light()
951 	struct files_struct *files = current->files;  in set_close_on_exec()  local
953 	spin_lock(&files->file_lock);  in set_close_on_exec()
954 	fdt = files_fdtable(files);  in set_close_on_exec()
959 	spin_unlock(&files->file_lock);  in set_close_on_exec()
964 	struct files_struct *files = current->files;  in get_close_on_exec()  local
968 	fdt = files_fdtable(files);  in get_close_on_exec()
974 static int do_dup2(struct files_struct *files,  in do_dup2()  argument
976 __releases(&files->file_lock)  in do_dup2()
987 	 * fget() treats larval files as absent.  Potentially interesting,  in do_dup2()
995 	fdt = files_fdtable(files);  in do_dup2()
1006 	spin_unlock(&files->file_lock);  in do_dup2()
1009 		filp_close(tofree, files);  in do_dup2()
1014 	spin_unlock(&files->file_lock);  in do_dup2()
1021 	struct files_struct *files = current->files;  in replace_fd()  local
1024 		return __close_fd(files, fd);  in replace_fd()
1029 	spin_lock(&files->file_lock);  in replace_fd()
1030 	err = expand_files(files, fd);  in replace_fd()
1033 	return do_dup2(files, file, fd, flags);  in replace_fd()
1036 	spin_unlock(&files->file_lock);  in replace_fd()
1100 	struct files_struct *files = current->files;  in ksys_dup3()  local
1111 	spin_lock(&files->file_lock);  in ksys_dup3()
1112 	err = expand_files(files, newfd);  in ksys_dup3()
1121 	return do_dup2(files, file, newfd, flags);  in ksys_dup3()
1126 	spin_unlock(&files->file_lock);  in ksys_dup3()
1138 		struct files_struct *files = current->files;  in SYSCALL_DEFINE2()  local
1142 		if (!fcheck_files(files, oldfd))  in SYSCALL_DEFINE2()
1178 int iterate_fd(struct files_struct *files, unsigned n,  in iterate_fd()  argument
1184 	if (!files)  in iterate_fd()
1186 	spin_lock(&files->file_lock);  in iterate_fd()
1187 	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {  in iterate_fd()
1189 		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);  in iterate_fd()
1196 	spin_unlock(&files->file_lock);  in iterate_fd()