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.
151  * The files->file_lock should be held on entry, and will be held on exit.
153 static int expand_fdtable(struct files_struct *files, unsigned int nr)  in expand_fdtable()  argument
154 	__releases(files->file_lock)  in expand_fdtable()
155 	__acquires(files->file_lock)  in expand_fdtable()
159 	spin_unlock(&files->file_lock);  in expand_fdtable()
165 	if (atomic_read(&files->count) > 1)  in expand_fdtable()
168 	spin_lock(&files->file_lock);  in expand_fdtable()
179 	cur_fdt = files_fdtable(files);  in expand_fdtable()
182 	rcu_assign_pointer(files->fdt, new_fdt);  in expand_fdtable()
183 	if (cur_fdt != &files->fdtab)  in expand_fdtable()
191  * Expand files.
194  * Return <0 error code on error; 0 when nothing done; 1 when files were
196  * The files->file_lock should be held on entry, and will be held on exit.
198 static int expand_files(struct files_struct *files, unsigned int nr)  in expand_files()  argument
199 	__releases(files->file_lock)  in expand_files()
200 	__acquires(files->file_lock)  in expand_files()
206 	fdt = files_fdtable(files);  in expand_files()
216 	if (unlikely(files->resize_in_progress)) {  in expand_files()
217 		spin_unlock(&files->file_lock);  in expand_files()
219 		wait_event(files->resize_wait, !files->resize_in_progress);  in expand_files()
220 		spin_lock(&files->file_lock);  in expand_files()
225 	files->resize_in_progress = true;  in expand_files()
226 	expanded = expand_fdtable(files, nr);  in expand_files()
227 	files->resize_in_progress = false;  in expand_files()
229 	wake_up_all(&files->resize_wait);  in expand_files()
283  * Allocate a new files structure and copy contents from the
284  * passed in files structure.
360 			 * instantiated in the files array if a sibling thread  in dup_fd()
383 static struct fdtable *close_files(struct files_struct * files)  in close_files()  argument
388 	 * files structure.  in close_files()
390 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);  in close_files()
403 					filp_close(file, files);  in close_files()
415 void put_files_struct(struct files_struct *files)  in put_files_struct()  argument
417 	if (atomic_dec_and_test(&files->count)) {  in put_files_struct()
418 		struct fdtable *fdt = close_files(files);  in put_files_struct()
421 		if (fdt != &files->fdtab)  in put_files_struct()
423 		kmem_cache_free(files_cachep, files);  in put_files_struct()
429 	struct files_struct * files = tsk->files;  in exit_files()  local
431 	if (files) {  in exit_files()
433 		tsk->files = NULL;  in exit_files()
435 		put_files_struct(files);  in exit_files()
472 	struct files_struct *files = current->files;  in alloc_fd()  local
477 	spin_lock(&files->file_lock);  in alloc_fd()
479 	fdt = files_fdtable(files);  in alloc_fd()
481 	if (fd < files->next_fd)  in alloc_fd()
482 		fd = files->next_fd;  in alloc_fd()
488 	 * N.B. For clone tasks sharing a files structure, this test  in alloc_fd()
489 	 * will limit the total number of files that can be opened.  in alloc_fd()
495 	error = expand_files(files, fd);  in alloc_fd()
506 	if (start <= files->next_fd)  in alloc_fd()
507 		files->next_fd = fd + 1;  in alloc_fd()
524 	spin_unlock(&files->file_lock);  in alloc_fd()
539 static void __put_unused_fd(struct files_struct *files, unsigned int fd)  in __put_unused_fd()  argument
541 	struct fdtable *fdt = files_fdtable(files);  in __put_unused_fd()
543 	if (fd < files->next_fd)  in __put_unused_fd()
544 		files->next_fd = fd;  in __put_unused_fd()
549 	struct files_struct *files = current->files;  in put_unused_fd()  local
550 	spin_lock(&files->file_lock);  in put_unused_fd()
551 	__put_unused_fd(files, fd);  in put_unused_fd()
552 	spin_unlock(&files->file_lock);  in put_unused_fd()
560  * The VFS is full of places where we drop the files lock between
575 	struct files_struct *files = current->files;  in fd_install()  local
580 	if (unlikely(files->resize_in_progress)) {  in fd_install()
582 		spin_lock(&files->file_lock);  in fd_install()
583 		fdt = files_fdtable(files);  in fd_install()
586 		spin_unlock(&files->file_lock);  in fd_install()
591 	fdt = rcu_dereference_sched(files->fdt);  in fd_install()
601  * @files: file struct to retrieve file from
609 static struct file *pick_file(struct files_struct *files, unsigned fd)  in pick_file()  argument
614 	spin_lock(&files->file_lock);  in pick_file()
615 	fdt = files_fdtable(files);  in pick_file()
626 	__put_unused_fd(files, fd);  in pick_file()
629 	spin_unlock(&files->file_lock);  in pick_file()
635 	struct files_struct *files = current->files;  in close_fd()  local
638 	file = pick_file(files, fd);  in close_fd()
642 	return filp_close(file, files);  in close_fd()
648  * @cur_fds: files struct
705 	struct files_struct *cur_fds = me->files, *fds = NULL;  in __close_range()
753 		 * We're done closing the files we were supposed to. Time to install  in __close_range()
757 		me->files = cur_fds;  in __close_range()
766  * See close_fd_get_file() below, this variant assumes current->files->file_lock
771 	struct files_struct *files = current->files;  in __close_fd_get_file()  local
775 	fdt = files_fdtable(files);  in __close_fd_get_file()
782 	__put_unused_fd(files, fd);  in __close_fd_get_file()
798 	struct files_struct *files = current->files;  in close_fd_get_file()  local
801 	spin_lock(&files->file_lock);  in close_fd_get_file()
803 	spin_unlock(&files->file_lock);  in close_fd_get_file()
808 void do_close_on_exec(struct files_struct *files)  in do_close_on_exec()  argument
814 	spin_lock(&files->file_lock);  in do_close_on_exec()
818 		fdt = files_fdtable(files);  in do_close_on_exec()
833 			__put_unused_fd(files, fd);  in do_close_on_exec()
834 			spin_unlock(&files->file_lock);  in do_close_on_exec()
835 			filp_close(file, files);  in do_close_on_exec()
837 			spin_lock(&files->file_lock);  in do_close_on_exec()
841 	spin_unlock(&files->file_lock);  in do_close_on_exec()
844 static struct file *__fget_files(struct files_struct *files, unsigned int fd,  in __fget_files()  argument
851 	file = files_lookup_fd_rcu(files, fd);  in __fget_files()
870 	return __fget_files(current->files, fd, mask, refs);  in __fget()
895 	if (task->files)  in fget_task()
896 		file = __fget_files(task->files, fd, 0, 1);  in fget_task()
905 	struct files_struct *files;  in task_lookup_fd_rcu()  local
909 	files = task->files;  in task_lookup_fd_rcu()
910 	if (files)  in task_lookup_fd_rcu()
911 		file = files_lookup_fd_rcu(files, fd);  in task_lookup_fd_rcu()
920 	struct files_struct *files;  in task_lookup_next_fd_rcu()  local
925 	files = task->files;  in task_lookup_next_fd_rcu()
926 	if (files) {  in task_lookup_next_fd_rcu()
927 		for (; fd < files_fdtable(files)->max_fds; fd++) {  in task_lookup_next_fd_rcu()
928 			file = files_lookup_fd_rcu(files, fd);  in task_lookup_next_fd_rcu()
956 	struct files_struct *files = current->files;  in __fget_light()  local
959 	if (atomic_read(&files->count) == 1) {  in __fget_light()
960 		file = files_lookup_fd_raw(files, fd);  in __fget_light()
1009 	struct files_struct *files = current->files;  in set_close_on_exec()  local
1011 	spin_lock(&files->file_lock);  in set_close_on_exec()
1012 	fdt = files_fdtable(files);  in set_close_on_exec()
1017 	spin_unlock(&files->file_lock);  in set_close_on_exec()
1022 	struct files_struct *files = current->files;  in get_close_on_exec()  local
1026 	fdt = files_fdtable(files);  in get_close_on_exec()
1032 static int do_dup2(struct files_struct *files,  in do_dup2()  argument
1034 __releases(&files->file_lock)  in do_dup2()
1045 	 * fget() treats larval files as absent.  Potentially interesting,  in do_dup2()
1053 	fdt = files_fdtable(files);  in do_dup2()
1064 	spin_unlock(&files->file_lock);  in do_dup2()
1067 		filp_close(tofree, files);  in do_dup2()
1072 	spin_unlock(&files->file_lock);  in do_dup2()
1079 	struct files_struct *files = current->files;  in replace_fd()  local
1087 	spin_lock(&files->file_lock);  in replace_fd()
1088 	err = expand_files(files, fd);  in replace_fd()
1091 	return do_dup2(files, file, fd, flags);  in replace_fd()
1094 	spin_unlock(&files->file_lock);  in replace_fd()
1163 	struct files_struct *files = current->files;  in ksys_dup3()  local
1174 	spin_lock(&files->file_lock);  in ksys_dup3()
1175 	err = expand_files(files, newfd);  in ksys_dup3()
1176 	file = files_lookup_fd_locked(files, oldfd);  in ksys_dup3()
1184 	return do_dup2(files, file, newfd, flags);  in ksys_dup3()
1189 	spin_unlock(&files->file_lock);  in ksys_dup3()
1201 		struct files_struct *files = current->files;  in SYSCALL_DEFINE2()  local
1205 		if (!files_lookup_fd_rcu(files, oldfd))  in SYSCALL_DEFINE2()
1242 int iterate_fd(struct files_struct *files, unsigned n,  in iterate_fd()  argument
1248 	if (!files)  in iterate_fd()
1250 	spin_lock(&files->file_lock);  in iterate_fd()
1251 	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {  in iterate_fd()
1253 		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);  in iterate_fd()
1260 	spin_unlock(&files->file_lock);  in iterate_fd()