11 #include <linux/file.h>
41 /* SLAB cache for file structures */
46 /* Container for backing file with optional user path */
48 	struct file file;  member
52 static inline struct backing_file *backing_file(struct file *f)  in backing_file()
54 	return container_of(f, struct backing_file, file);  in backing_file()
57 struct path *backing_file_user_path(struct file *f)  in backing_file_user_path()
63 static inline void file_free(struct file *f)  in file_free()
108 		.procname	= "file-nr",
115 		.procname	= "file-max",
148 static int init_file(struct file *f, int flags, const struct cred *cred)  in init_file()
165 	 * the respective member when opening the file.  in init_file()
175 	 * refcount bumps we should reinitialize the reused file first.  in init_file()
181 /* Find an unused file structure and return a pointer to it.
182  * Returns an error pointer if some error happend e.g. we over file
191 struct file *alloc_empty_file(int flags, const struct cred *cred)  in alloc_empty_file()
194 	struct file *f;  in alloc_empty_file()
226 		pr_info("VFS: file-max limit %lu reached\n", get_max_files());  in alloc_empty_file()
235  * This is only for kernel internal use, and the allocate file must not be
236  * installed into file tables or such.
238 struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred)  in alloc_empty_file_noaccount()
240 	struct file *f;  in alloc_empty_file_noaccount()
262  * This is only for kernel internal use, and the allocate file must not be
263  * installed into file tables or such.
265 struct file *alloc_empty_backing_file(int flags, const struct cred *cred)  in alloc_empty_backing_file()
274 	error = init_file(&ff->file, flags, cred);  in alloc_empty_backing_file()
280 	ff->file.f_mode |= FMODE_BACKING | FMODE_NOACCOUNT;  in alloc_empty_backing_file()
281 	return &ff->file;  in alloc_empty_backing_file()
285  * file_init_path - initialize a 'struct file' based on path
287  * @file: the file to set up
288  * @path: the (dentry, vfsmount) pair for the new file
289  * @fop: the 'struct file_operations' for the new file
291 static void file_init_path(struct file *file, const struct path *path,  in file_init_path()  argument
294 	file->f_path = *path;  in file_init_path()
295 	file->f_inode = path->dentry->d_inode;  in file_init_path()
296 	file->f_mapping = path->dentry->d_inode->i_mapping;  in file_init_path()
297 	file->f_wb_err = filemap_sample_wb_err(file->f_mapping);  in file_init_path()
298 	file->f_sb_err = file_sample_sb_err(file);  in file_init_path()
300 		file->f_mode |= FMODE_LSEEK;  in file_init_path()
301 	if ((file->f_mode & FMODE_READ) &&  in file_init_path()
303 		file->f_mode |= FMODE_CAN_READ;  in file_init_path()
304 	if ((file->f_mode & FMODE_WRITE) &&  in file_init_path()
306 		file->f_mode |= FMODE_CAN_WRITE;  in file_init_path()
307 	file->f_iocb_flags = iocb_flags(file);  in file_init_path()
308 	file->f_mode |= FMODE_OPENED;  in file_init_path()
309 	file->f_op = fop;  in file_init_path()
310 	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)  in file_init_path()
315  * alloc_file - allocate and initialize a 'struct file'
317  * @path: the (dentry, vfsmount) pair for the new file
318  * @flags: O_... flags with which the new file will be opened
319  * @fop: the 'struct file_operations' for the new file
321 static struct file *alloc_file(const struct path *path, int flags,  in alloc_file()
324 	struct file *file;  in alloc_file()  local
326 	file = alloc_empty_file(flags, current_cred());  in alloc_file()
327 	if (!IS_ERR(file))  in alloc_file()
328 		file_init_path(file, path, fop);  in alloc_file()
329 	return file;  in alloc_file()
345 struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,  in alloc_file_pseudo()
351 	struct file *file;  in alloc_file_pseudo()  local
357 	file = alloc_file(&path, flags, fops);  in alloc_file_pseudo()
358 	if (IS_ERR(file)) {  in alloc_file_pseudo()
362 	return file;  in alloc_file_pseudo()
366 struct file *alloc_file_pseudo_noaccount(struct inode *inode,  in alloc_file_pseudo_noaccount()
373 	struct file *file;  in alloc_file_pseudo_noaccount()  local
379 	file = alloc_empty_file_noaccount(flags, current_cred());  in alloc_file_pseudo_noaccount()
380 	if (IS_ERR(file)) {  in alloc_file_pseudo_noaccount()
383 		return file;  in alloc_file_pseudo_noaccount()
385 	file_init_path(file, &path, fops);  in alloc_file_pseudo_noaccount()
386 	return file;  in alloc_file_pseudo_noaccount()
390 struct file *alloc_file_clone(struct file *base, int flags,  in alloc_file_clone()
393 	struct file *f;  in alloc_file_clone()
403 /* the real guts of fput() - releasing the last reference to file
405 static void __fput(struct file *file)  in __fput()  argument
407 	struct dentry *dentry = file->f_path.dentry;  in __fput()
408 	struct vfsmount *mnt = file->f_path.mnt;  in __fput()
409 	struct inode *inode = file->f_inode;  in __fput()
410 	fmode_t mode = file->f_mode;  in __fput()
412 	if (unlikely(!(file->f_mode & FMODE_OPENED)))  in __fput()
417 	fsnotify_close(file);  in __fput()
420 	 * in the file cleanup chain.  in __fput()
422 	eventpoll_release(file);  in __fput()
423 	locks_remove_file(file);  in __fput()
425 	security_file_release(file);  in __fput()
426 	if (unlikely(file->f_flags & FASYNC)) {  in __fput()
427 		if (file->f_op->fasync)  in __fput()
428 			file->f_op->fasync(-1, file, 0);  in __fput()
430 	if (file->f_op->release)  in __fput()
431 		file->f_op->release(inode, file);  in __fput()
436 	fops_put(file->f_op);  in __fput()
437 	file_f_owner_release(file);  in __fput()
438 	put_file_access(file);  in __fput()
444 	file_free(file);  in __fput()
451 	struct file *f, *t;  in delayed_fput()
459 	__fput(container_of(work, struct file, f_task_work));  in ____fput()
466  * not left us with opened struct file waiting for __fput() - execve()
480 void fput(struct file *file)  in fput()  argument
482 	if (atomic_long_dec_and_test(&file->f_count)) {  in fput()
485 		if (unlikely(!(file->f_mode & (FMODE_BACKING | FMODE_OPENED)))) {  in fput()
486 			file_free(file);  in fput()
490 			init_task_work(&file->f_task_work, ____fput);  in fput()
491 			if (!task_work_add(task, &file->f_task_work, TWA_RESUME))  in fput()
496 			 * fput to avoid leaking *file.  in fput()
500 		if (llist_add(&file->f_llist, &delayed_fput_list))  in fput()
509  * for this specific struct file it won't involve anything that would
513 void __fput_sync(struct file *file)  in __fput_sync()  argument
515 	if (atomic_long_dec_and_test(&file->f_count))  in __fput_sync()
516 		__fput(file);  in __fput_sync()
526 		.freeptr_offset = offsetof(struct file, f_freeptr),  in files_init()
529 	filp_cachep = kmem_cache_create("filp", sizeof(struct file), &args,  in files_init()
536  * One file with associated inode and dcache is very roughly 1K. Per default