7 #include <linux/file.h>
14 #include <linux/backing-file.h>
27 static struct file *ovl_open_realfile(const struct file *file,  in ovl_open_realfile()  argument
31 	struct inode *inode = file_inode(file);  in ovl_open_realfile()
33 	struct file *realfile;  in ovl_open_realfile()
35 	int flags = file->f_flags | OVL_OPEN_FLAGS;  in ovl_open_realfile()
51 		realfile = backing_file_open(&file->f_path, flags, realpath,  in ovl_open_realfile()
57 		 file, file, ovl_whatisit(inode, realinode), file->f_flags,  in ovl_open_realfile()
65 static int ovl_change_flags(struct file *file, unsigned int flags)  in ovl_change_flags()  argument
67 	struct inode *inode = file_inode(file);  in ovl_change_flags()
72 	if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))  in ovl_change_flags()
75 	if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT))  in ovl_change_flags()
78 	if (file->f_op->check_flags) {  in ovl_change_flags()
79 		err = file->f_op->check_flags(flags);  in ovl_change_flags()
84 	spin_lock(&file->f_lock);  in ovl_change_flags()
85 	file->f_flags = (file->f_flags & ~OVL_SETFL_MASK) | flags;  in ovl_change_flags()
86 	file->f_iocb_flags = iocb_flags(file);  in ovl_change_flags()
87 	spin_unlock(&file->f_lock);  in ovl_change_flags()
92 static int ovl_real_fdget_meta(const struct file *file, struct fd *real,  in ovl_real_fdget_meta()  argument
95 	struct dentry *dentry = file_dentry(file);  in ovl_real_fdget_meta()
96 	struct file *realfile = file->private_data;  in ovl_real_fdget_meta()
117 		struct file *f = ovl_open_realfile(file, &realpath);  in ovl_real_fdget_meta()
125 	if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS))  in ovl_real_fdget_meta()
126 		return ovl_change_flags(realfile, file->f_flags);  in ovl_real_fdget_meta()
131 static int ovl_real_fdget(const struct file *file, struct fd *real)  in ovl_real_fdget()  argument
133 	if (d_is_dir(file_dentry(file))) {  in ovl_real_fdget()
134 		struct file *f = ovl_dir_real_file(file, false);  in ovl_real_fdget()
141 	return ovl_real_fdget_meta(file, real, false);  in ovl_real_fdget()
144 static int ovl_open(struct inode *inode, struct file *file)  in ovl_open()  argument
146 	struct dentry *dentry = file_dentry(file);  in ovl_open()
147 	struct file *realfile;  in ovl_open()
156 	err = ovl_maybe_copy_up(dentry, file->f_flags);  in ovl_open()
161 	file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);  in ovl_open()
167 	realfile = ovl_open_realfile(file, &realpath);  in ovl_open()
171 	file->private_data = realfile;  in ovl_open()
176 static int ovl_release(struct inode *inode, struct file *file)  in ovl_release()  argument
178 	fput(file->private_data);  in ovl_release()
183 static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)  in ovl_llseek()  argument
185 	struct inode *inode = file_inode(file);  in ovl_llseek()
196 			return file->f_pos;  in ovl_llseek()
199 			return vfs_setpos(file, 0, 0);  in ovl_llseek()
202 	ret = ovl_real_fdget(file, &real);  in ovl_llseek()
207 	 * Overlay file f_pos is the master copy that is preserved  in ovl_llseek()
211 	 * files, so we use the real file to perform seeks.  in ovl_llseek()
214 	fd_file(real)->f_pos = file->f_pos;  in ovl_llseek()
220 	file->f_pos = fd_file(real)->f_pos;  in ovl_llseek()
228 static void ovl_file_modified(struct file *file)  in ovl_file_modified()  argument
231 	ovl_copyattr(file_inode(file));  in ovl_file_modified()
234 static void ovl_file_end_write(struct file *file, loff_t pos, ssize_t ret)  in ovl_file_end_write()  argument
236 	ovl_file_modified(file);  in ovl_file_end_write()
239 static void ovl_file_accessed(struct file *file)  in ovl_file_accessed()  argument
245 	if (file->f_flags & O_NOATIME)  in ovl_file_accessed()
248 	inode = file_inode(file);  in ovl_file_accessed()
264 	touch_atime(&file->f_path);  in ovl_file_accessed()
269 	struct file *file = iocb->ki_filp;  in ovl_read_iter()  local
273 		.cred = ovl_creds(file_inode(file)->i_sb),  in ovl_read_iter()
274 		.user_file = file,  in ovl_read_iter()
281 	ret = ovl_real_fdget(file, &real);  in ovl_read_iter()
294 	struct file *file = iocb->ki_filp;  in ovl_write_iter()  local
295 	struct inode *inode = file_inode(file);  in ovl_write_iter()
301 		.user_file = file,  in ovl_write_iter()
312 	ret = ovl_real_fdget(file, &real);  in ovl_write_iter()
333 static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,  in ovl_splice_read()
361  * the real file.
363 static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,  in ovl_splice_write()
392 static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)  in ovl_fsync()  argument
398 	ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));  in ovl_fsync()
402 	ret = ovl_real_fdget_meta(file, &real, !datasync);  in ovl_fsync()
406 	/* Don't sync lower file for fear of receiving EROFS error */  in ovl_fsync()
407 	if (file_inode(fd_file(real)) == ovl_inode_upper(file_inode(file))) {  in ovl_fsync()
408 		old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fsync()
418 static int ovl_mmap(struct file *file, struct vm_area_struct *vma)  in ovl_mmap()  argument
420 	struct file *realfile = file->private_data;  in ovl_mmap()
422 		.cred = ovl_creds(file_inode(file)->i_sb),  in ovl_mmap()
423 		.user_file = file,  in ovl_mmap()
430 static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)  in ovl_fallocate()  argument
432 	struct inode *inode = file_inode(file);  in ovl_fallocate()
440 	ret = file_remove_privs(file);  in ovl_fallocate()
444 	ret = ovl_real_fdget(file, &real);  in ovl_fallocate()
448 	old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fallocate()
453 	ovl_file_modified(file);  in ovl_fallocate()
463 static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)  in ovl_fadvise()  argument
469 	ret = ovl_real_fdget(file, &real);  in ovl_fadvise()
473 	old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fadvise()
488 static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,  in ovl_copyfile()
489 			    struct file *file_out, loff_t pos_out,  in ovl_copyfile()
548 static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,  in ovl_copy_file_range()
549 				   struct file *file_out, loff_t pos_out,  in ovl_copy_file_range()
556 static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,  in ovl_remap_file_range()
557 				   struct file *file_out, loff_t pos_out,  in ovl_remap_file_range()
583 static int ovl_flush(struct file *file, fl_owner_t id)  in ovl_flush()  argument
589 	err = ovl_real_fdget(file, &real);  in ovl_flush()
594 		old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_flush()