46  * space if any.  This does not copy the file pointers.  Called with the files
69  * clear the extra space.  Called with the files spinlock held for write.
146  * The files->file_lock should be held on entry, and will be held on exit.
148 static int expand_fdtable(struct files_struct *files, unsigned int nr)  in expand_fdtable()  argument
149 	__releases(files->file_lock)  in expand_fdtable()
150 	__acquires(files->file_lock)  in expand_fdtable()
154 	spin_unlock(&files->file_lock);  in expand_fdtable()
160 	if (atomic_read(&files->count) > 1)  in expand_fdtable()
163 	spin_lock(&files->file_lock);  in expand_fdtable()
174 	cur_fdt = files_fdtable(files);  in expand_fdtable()
177 	rcu_assign_pointer(files->fdt, new_fdt);  in expand_fdtable()
178 	if (cur_fdt != &files->fdtab)  in expand_fdtable()
186  * Expand files.
189  * Return <0 error code on error; 0 when nothing done; 1 when files were
191  * The files->file_lock should be held on entry, and will be held on exit.
193 static int expand_files(struct files_struct *files, unsigned int nr)  in expand_files()  argument
194 	__releases(files->file_lock)  in expand_files()
195 	__acquires(files->file_lock)  in expand_files()
201 	fdt = files_fdtable(files);  in expand_files()
211 	if (unlikely(files->resize_in_progress)) {  in expand_files()
212 		spin_unlock(&files->file_lock);  in expand_files()
214 		wait_event(files->resize_wait, !files->resize_in_progress);  in expand_files()
215 		spin_lock(&files->file_lock);  in expand_files()
220 	files->resize_in_progress = true;  in expand_files()
221 	expanded = expand_fdtable(files, nr);  in expand_files()
222 	files->resize_in_progress = false;  in expand_files()
224 	wake_up_all(&files->resize_wait);  in expand_files()
268  * Allocate a new files structure and copy contents from the
269  * passed in files structure.
345 			 * instantiated in the files array if a sibling thread  in dup_fd()
368 static struct fdtable *close_files(struct files_struct * files)  in close_files()  argument
373 	 * files structure.  in close_files()
375 	struct fdtable *fdt = rcu_dereference_raw(files->fdt);  in close_files()
388 					filp_close(file, files);  in close_files()
402 	struct files_struct *files;  in get_files_struct()  local
405 	files = task->files;  in get_files_struct()
406 	if (files)  in get_files_struct()
407 		atomic_inc(&files->count);  in get_files_struct()
410 	return files;  in get_files_struct()
413 void put_files_struct(struct files_struct *files)  in put_files_struct()  argument
415 	if (atomic_dec_and_test(&files->count)) {  in put_files_struct()
416 		struct fdtable *fdt = close_files(files);  in put_files_struct()
419 		if (fdt != &files->fdtab)  in put_files_struct()
421 		kmem_cache_free(files_cachep, files);  in put_files_struct()
425 void reset_files_struct(struct files_struct *files)  in reset_files_struct()  argument
430 	old = tsk->files;  in reset_files_struct()
432 	tsk->files = files;  in reset_files_struct()
439 	struct files_struct * files = tsk->files;  in exit_files()  local
441 	if (files) {  in exit_files()
443 		tsk->files = NULL;  in exit_files()
445 		put_files_struct(files);  in exit_files()
480 int __alloc_fd(struct files_struct *files,  in __alloc_fd()  argument
487 	spin_lock(&files->file_lock);  in __alloc_fd()
489 	fdt = files_fdtable(files);  in __alloc_fd()
491 	if (fd < files->next_fd)  in __alloc_fd()
492 		fd = files->next_fd;  in __alloc_fd()
498 	 * N.B. For clone tasks sharing a files structure, this test  in __alloc_fd()
499 	 * will limit the total number of files that can be opened.  in __alloc_fd()
505 	error = expand_files(files, fd);  in __alloc_fd()
516 	if (start <= files->next_fd)  in __alloc_fd()
517 		files->next_fd = fd + 1;  in __alloc_fd()
534 	spin_unlock(&files->file_lock);  in __alloc_fd()
540 	return __alloc_fd(current->files, start, rlimit(RLIMIT_NOFILE), flags);  in alloc_fd()
545 	return __alloc_fd(current->files, 0, rlimit(RLIMIT_NOFILE), flags);  in get_unused_fd_flags()
549 static void __put_unused_fd(struct files_struct *files, unsigned int fd)  in __put_unused_fd()  argument
551 	struct fdtable *fdt = files_fdtable(files);  in __put_unused_fd()
553 	if (fd < files->next_fd)  in __put_unused_fd()
554 		files->next_fd = fd;  in __put_unused_fd()
559 	struct files_struct *files = current->files;  in put_unused_fd()  local
560 	spin_lock(&files->file_lock);  in put_unused_fd()
561 	__put_unused_fd(files, fd);  in put_unused_fd()
562 	spin_unlock(&files->file_lock);  in put_unused_fd()
570  * The VFS is full of places where we drop the files lock between
581  * your throat.  'files' *MUST* be either current->files or obtained
587 void __fd_install(struct files_struct *files, unsigned int fd,  in __fd_install()  argument
594 	if (unlikely(files->resize_in_progress)) {  in __fd_install()
596 		spin_lock(&files->file_lock);  in __fd_install()
597 		fdt = files_fdtable(files);  in __fd_install()
600 		spin_unlock(&files->file_lock);  in __fd_install()
605 	fdt = rcu_dereference_sched(files->fdt);  in __fd_install()
613 	__fd_install(current->files, fd, file);  in fd_install()
621 int __close_fd(struct files_struct *files, unsigned fd)  in __close_fd()  argument
626 	spin_lock(&files->file_lock);  in __close_fd()
627 	fdt = files_fdtable(files);  in __close_fd()
634 	__put_unused_fd(files, fd);  in __close_fd()
635 	spin_unlock(&files->file_lock);  in __close_fd()
636 	return filp_close(file, files);  in __close_fd()
639 	spin_unlock(&files->file_lock);  in __close_fd()
649 	struct files_struct *files = current->files;  in __close_fd_get_file()  local
653 	spin_lock(&files->file_lock);  in __close_fd_get_file()
654 	fdt = files_fdtable(files);  in __close_fd_get_file()
661 	__put_unused_fd(files, fd);  in __close_fd_get_file()
662 	spin_unlock(&files->file_lock);  in __close_fd_get_file()
665 	return filp_close(file, files);  in __close_fd_get_file()
668 	spin_unlock(&files->file_lock);  in __close_fd_get_file()
673 void do_close_on_exec(struct files_struct *files)  in do_close_on_exec()  argument
679 	spin_lock(&files->file_lock);  in do_close_on_exec()
683 		fdt = files_fdtable(files);  in do_close_on_exec()
698 			__put_unused_fd(files, fd);  in do_close_on_exec()
699 			spin_unlock(&files->file_lock);  in do_close_on_exec()
700 			filp_close(file, files);  in do_close_on_exec()
702 			spin_lock(&files->file_lock);  in do_close_on_exec()
706 	spin_unlock(&files->file_lock);  in do_close_on_exec()
711 	struct files_struct *files = current->files;  in __fget()  local
716 	file = fcheck_files(files, fd);  in __fget()
767 	struct files_struct *files = current->files;  in __fget_light()  local
770 	if (atomic_read(&files->count) == 1) {  in __fget_light()
771 		file = __fcheck_files(files, fd);  in __fget_light()
820 	struct files_struct *files = current->files;  in set_close_on_exec()  local
822 	spin_lock(&files->file_lock);  in set_close_on_exec()
823 	fdt = files_fdtable(files);  in set_close_on_exec()
828 	spin_unlock(&files->file_lock);  in set_close_on_exec()
833 	struct files_struct *files = current->files;  in get_close_on_exec()  local
837 	fdt = files_fdtable(files);  in get_close_on_exec()
843 static int do_dup2(struct files_struct *files,  in do_dup2()  argument
845 __releases(&files->file_lock)  in do_dup2()
856 	 * fget() treats larval files as absent.  Potentially interesting,  in do_dup2()
864 	fdt = files_fdtable(files);  in do_dup2()
875 	spin_unlock(&files->file_lock);  in do_dup2()
878 		filp_close(tofree, files);  in do_dup2()
883 	spin_unlock(&files->file_lock);  in do_dup2()
890 	struct files_struct *files = current->files;  in replace_fd()  local
893 		return __close_fd(files, fd);  in replace_fd()
898 	spin_lock(&files->file_lock);  in replace_fd()
899 	err = expand_files(files, fd);  in replace_fd()
902 	return do_dup2(files, file, fd, flags);  in replace_fd()
905 	spin_unlock(&files->file_lock);  in replace_fd()
913 	struct files_struct *files = current->files;  in ksys_dup3()  local
924 	spin_lock(&files->file_lock);  in ksys_dup3()
925 	err = expand_files(files, newfd);  in ksys_dup3()
934 	return do_dup2(files, file, newfd, flags);  in ksys_dup3()
939 	spin_unlock(&files->file_lock);  in ksys_dup3()
951 		struct files_struct *files = current->files;  in SYSCALL_DEFINE2()  local
955 		if (!fcheck_files(files, oldfd))  in SYSCALL_DEFINE2()
996 int iterate_fd(struct files_struct *files, unsigned n,  in iterate_fd()  argument
1002 	if (!files)  in iterate_fd()
1004 	spin_lock(&files->file_lock);  in iterate_fd()
1005 	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {  in iterate_fd()
1007 		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);  in iterate_fd()
1014 	spin_unlock(&files->file_lock);  in iterate_fd()