51  * space if any.  This does not copy the file pointers.  Called with the files
74  * clear the extra space.  Called with the files spinlock held for write.
167  * The files->file_lock should be held on entry, and will be held on exit.
169 static int expand_fdtable(struct files_struct *files, unsigned int nr)  in expand_fdtable()  argument
170 	__releases(files->file_lock)  in expand_fdtable()
171 	__acquires(files->file_lock)  in expand_fdtable()
175 	spin_unlock(&files->file_lock);  in expand_fdtable()
181 	if (atomic_read(&files->count) > 1)  in expand_fdtable()
184 	spin_lock(&files->file_lock);  in expand_fdtable()
195 	cur_fdt = files_fdtable(files);  in expand_fdtable()
198 	rcu_assign_pointer(files->fdt, new_fdt);  in expand_fdtable()
199 	if (cur_fdt != &files->fdtab)  in expand_fdtable()
207  * Expand files.
210  * Return <0 error code on error; 0 when nothing done; 1 when files were
212  * The files->file_lock should be held on entry, and will be held on exit.
214 static int expand_files(struct files_struct *files, unsigned int nr)  in expand_files()  argument
215 	__releases(files->file_lock)  in expand_files()
216 	__acquires(files->file_lock)  in expand_files()
222 	fdt = files_fdtable(files);  in expand_files()
232 	if (unlikely(files->resize_in_progress)) {  in expand_files()
233 		spin_unlock(&files->file_lock);  in expand_files()
235 		wait_event(files->resize_wait, !files->resize_in_progress);  in expand_files()
236 		spin_lock(&files->file_lock);  in expand_files()
241 	files->resize_in_progress = true;  in expand_files()
242 	expanded = expand_fdtable(files, nr);  in expand_files()
243 	files->resize_in_progress = false;  in expand_files()
245 	wake_up_all(&files->resize_wait);  in expand_files()
312  * Allocate a new files structure and copy contents from the
313  * passed in files structure.
389 			 * instantiated in the files array if a sibling thread  in dup_fd()
412 static struct fdtable *close_files(struct files_struct * files)  in close_files()  argument
417 	 * files structure.  in close_files()
419 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);  in close_files()
432 					filp_close(file, files);  in close_files()
444 void put_files_struct(struct files_struct *files)  in put_files_struct()  argument
446 	if (atomic_dec_and_test(&files->count)) {  in put_files_struct()
447 		struct fdtable *fdt = close_files(files);  in put_files_struct()
450 		if (fdt != &files->fdtab)  in put_files_struct()
452 		kmem_cache_free(files_cachep, files);  in put_files_struct()
458 	struct files_struct * files = tsk->files;  in exit_files()  local
460 	if (files) {  in exit_files()
462 		tsk->files = NULL;  in exit_files()
464 		put_files_struct(files);  in exit_files()
501 	struct files_struct *files = current->files;  in alloc_fd()  local
506 	spin_lock(&files->file_lock);  in alloc_fd()
508 	fdt = files_fdtable(files);  in alloc_fd()
510 	if (fd < files->next_fd)  in alloc_fd()
511 		fd = files->next_fd;  in alloc_fd()
517 	 * N.B. For clone tasks sharing a files structure, this test  in alloc_fd()
518 	 * will limit the total number of files that can be opened.  in alloc_fd()
524 	error = expand_files(files, fd);  in alloc_fd()
535 	if (start <= files->next_fd)  in alloc_fd()
536 		files->next_fd = fd + 1;  in alloc_fd()
553 	spin_unlock(&files->file_lock);  in alloc_fd()
568 static void __put_unused_fd(struct files_struct *files, unsigned int fd)  in __put_unused_fd()  argument
570 	struct fdtable *fdt = files_fdtable(files);  in __put_unused_fd()
572 	if (fd < files->next_fd)  in __put_unused_fd()
573 		files->next_fd = fd;  in __put_unused_fd()
578 	struct files_struct *files = current->files;  in put_unused_fd()  local
579 	spin_lock(&files->file_lock);  in put_unused_fd()
580 	__put_unused_fd(files, fd);  in put_unused_fd()
581 	spin_unlock(&files->file_lock);  in put_unused_fd()
589  * The VFS is full of places where we drop the files lock between
604 	struct files_struct *files = current->files;  in fd_install()  local
612 	if (unlikely(files->resize_in_progress)) {  in fd_install()
614 		spin_lock(&files->file_lock);  in fd_install()
615 		fdt = files_fdtable(files);  in fd_install()
618 		spin_unlock(&files->file_lock);  in fd_install()
623 	fdt = rcu_dereference_sched(files->fdt);  in fd_install()
633  * @files: file struct to retrieve file from
642 struct file *file_close_fd_locked(struct files_struct *files, unsigned fd)  in file_close_fd_locked()  argument
644 	struct fdtable *fdt = files_fdtable(files);  in file_close_fd_locked()
647 	lockdep_assert_held(&files->file_lock);  in file_close_fd_locked()
656 		__put_unused_fd(files, fd);  in file_close_fd_locked()
663 	struct files_struct *files = current->files;  in close_fd()  local
666 	spin_lock(&files->file_lock);  in close_fd()
667 	file = file_close_fd_locked(files, fd);  in close_fd()
668 	spin_unlock(&files->file_lock);  in close_fd()
672 	return filp_close(file, files);  in close_fd()
703 static inline void __range_close(struct files_struct *files, unsigned int fd,  in __range_close()  argument
709 	spin_lock(&files->file_lock);  in __range_close()
710 	n = last_fd(files_fdtable(files));  in __range_close()
714 		file = file_close_fd_locked(files, fd);  in __range_close()
716 			spin_unlock(&files->file_lock);  in __range_close()
717 			filp_close(file, files);  in __range_close()
719 			spin_lock(&files->file_lock);  in __range_close()
721 			spin_unlock(&files->file_lock);  in __range_close()
723 			spin_lock(&files->file_lock);  in __range_close()
726 	spin_unlock(&files->file_lock);  in __range_close()
742 	struct files_struct *cur_fds = me->files, *fds = NULL;  in __close_range()
790 		 * We're done closing the files we were supposed to. Time to install  in __close_range()
794 		me->files = cur_fds;  in __close_range()
812 	struct files_struct *files = current->files;  in file_close_fd()  local
815 	spin_lock(&files->file_lock);  in file_close_fd()
816 	file = file_close_fd_locked(files, fd);  in file_close_fd()
817 	spin_unlock(&files->file_lock);  in file_close_fd()
822 void do_close_on_exec(struct files_struct *files)  in do_close_on_exec()  argument
828 	spin_lock(&files->file_lock);  in do_close_on_exec()
832 		fdt = files_fdtable(files);  in do_close_on_exec()
847 			__put_unused_fd(files, fd);  in do_close_on_exec()
848 			spin_unlock(&files->file_lock);  in do_close_on_exec()
849 			filp_close(file, files);  in do_close_on_exec()
851 			spin_lock(&files->file_lock);  in do_close_on_exec()
855 	spin_unlock(&files->file_lock);  in do_close_on_exec()
954 static inline struct file *__fget_files_rcu(struct files_struct *files,  in __fget_files_rcu()  argument
959 		struct fdtable *fdt = rcu_dereference_raw(files->fdt);  in __fget_files_rcu()
1008 		    unlikely(rcu_dereference_raw(files->fdt) != fdt)) {  in __fget_files_rcu()
1030 static struct file *__fget_files(struct files_struct *files, unsigned int fd,  in __fget_files()  argument
1036 	file = __fget_files_rcu(files, fd, mask);  in __fget_files()
1044 	return __fget_files(current->files, fd, mask);  in __fget()
1064 	if (task->files)  in fget_task()
1065 		file = __fget_files(task->files, fd, 0);  in fget_task()
1073 	return __fget_files_rcu(current->files, fd, 0);  in lookup_fdget_rcu()
1081 	struct files_struct *files;  in task_lookup_fdget_rcu()  local
1085 	files = task->files;  in task_lookup_fdget_rcu()
1086 	if (files)  in task_lookup_fdget_rcu()
1087 		file = __fget_files_rcu(files, fd, 0);  in task_lookup_fdget_rcu()
1096 	struct files_struct *files;  in task_lookup_next_fdget_rcu()  local
1101 	files = task->files;  in task_lookup_next_fdget_rcu()
1102 	if (files) {  in task_lookup_next_fdget_rcu()
1103 		for (; fd < files_fdtable(files)->max_fds; fd++) {  in task_lookup_next_fdget_rcu()
1104 			file = __fget_files_rcu(files, fd, 0);  in task_lookup_next_fdget_rcu()
1133 	struct files_struct *files = current->files;  in __fget_light()  local
1145 	if (likely(atomic_read_acquire(&files->count) == 1)) {  in __fget_light()
1146 		file = files_lookup_fd_raw(files, fd);  in __fget_light()
1151 		file = __fget_files(files, fd, mask);  in __fget_light()
1209 	struct files_struct *files = current->files;  in set_close_on_exec()  local
1211 	spin_lock(&files->file_lock);  in set_close_on_exec()
1212 	fdt = files_fdtable(files);  in set_close_on_exec()
1217 	spin_unlock(&files->file_lock);  in set_close_on_exec()
1222 	struct files_struct *files = current->files;  in get_close_on_exec()  local
1226 	fdt = files_fdtable(files);  in get_close_on_exec()
1232 static int do_dup2(struct files_struct *files,  in do_dup2()  argument
1234 __releases(&files->file_lock)  in do_dup2()
1245 	 * fget() treats larval files as absent.  Potentially interesting,  in do_dup2()
1253 	fdt = files_fdtable(files);  in do_dup2()
1264 	spin_unlock(&files->file_lock);  in do_dup2()
1267 		filp_close(tofree, files);  in do_dup2()
1272 	spin_unlock(&files->file_lock);  in do_dup2()
1279 	struct files_struct *files = current->files;  in replace_fd()  local
1287 	spin_lock(&files->file_lock);  in replace_fd()
1288 	err = expand_files(files, fd);  in replace_fd()
1291 	return do_dup2(files, file, fd, flags);  in replace_fd()
1294 	spin_unlock(&files->file_lock);  in replace_fd()
1358 	struct files_struct *files = current->files;  in ksys_dup3()  local
1369 	spin_lock(&files->file_lock);  in ksys_dup3()
1370 	err = expand_files(files, newfd);  in ksys_dup3()
1371 	file = files_lookup_fd_locked(files, oldfd);  in ksys_dup3()
1379 	return do_dup2(files, file, newfd, flags);  in ksys_dup3()
1384 	spin_unlock(&files->file_lock);  in ksys_dup3()
1396 		struct files_struct *files = current->files;  in SYSCALL_DEFINE2()  local
1401 		f = __fget_files_rcu(files, oldfd, 0);  in SYSCALL_DEFINE2()
1441 int iterate_fd(struct files_struct *files, unsigned n,  in iterate_fd()  argument
1447 	if (!files)  in iterate_fd()
1449 	spin_lock(&files->file_lock);  in iterate_fd()
1450 	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {  in iterate_fd()
1452 		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);  in iterate_fd()
1459 	spin_unlock(&files->file_lock);  in iterate_fd()