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()
93 	struct file *realfile;
94 	struct file *upperfile;
97 struct ovl_file *ovl_file_alloc(struct file *realfile)  in ovl_file_alloc()
116 static bool ovl_is_real_file(const struct file *realfile,  in ovl_is_real_file()
122 static struct file *ovl_real_file_path(const struct file *file,  in ovl_real_file_path()  argument
125 	struct ovl_file *of = file->private_data;  in ovl_real_file_path()
126 	struct file *realfile = of->realfile;  in ovl_real_file_path()
134 	 * metacopied file.  We need the upperfile either way, so see if it  in ovl_real_file_path()
138 		struct file *upperfile = READ_ONCE(of->upperfile);  in ovl_real_file_path()
139 		struct file *old;  in ovl_real_file_path()
142 			upperfile = ovl_open_realfile(file, realpath);  in ovl_real_file_path()
154 		 * Stored file must be from the right inode, unless someone's  in ovl_real_file_path()
164 	if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS)) {  in ovl_real_file_path()
165 		int err = ovl_change_flags(realfile, file->f_flags);  in ovl_real_file_path()
174 static struct file *ovl_real_file(const struct file *file)  in ovl_real_file()  argument
176 	struct dentry *dentry = file_dentry(file);  in ovl_real_file()
181 		struct file *f = ovl_dir_real_file(file, false);  in ovl_real_file()
195 	return ovl_real_file_path(file, &realpath);  in ovl_real_file()
198 static int ovl_open(struct inode *inode, struct file *file)  in ovl_open()  argument
200 	struct dentry *dentry = file_dentry(file);  in ovl_open()
201 	struct file *realfile;  in ovl_open()
211 	err = ovl_maybe_copy_up(dentry, file->f_flags);  in ovl_open()
216 	file->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);  in ovl_open()
222 	realfile = ovl_open_realfile(file, &realpath);  in ovl_open()
232 	file->private_data = of;  in ovl_open()
237 static int ovl_release(struct inode *inode, struct file *file)  in ovl_release()  argument
239 	ovl_file_free(file->private_data);  in ovl_release()
243 static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)  in ovl_llseek()  argument
245 	struct inode *inode = file_inode(file);  in ovl_llseek()
246 	struct file *realfile;  in ovl_llseek()
256 			return file->f_pos;  in ovl_llseek()
259 			return vfs_setpos(file, 0, 0);  in ovl_llseek()
262 	realfile = ovl_real_file(file);  in ovl_llseek()
267 	 * Overlay file f_pos is the master copy that is preserved  in ovl_llseek()
271 	 * files, so we use the real file to perform seeks.  in ovl_llseek()
274 	realfile->f_pos = file->f_pos;  in ovl_llseek()
280 	file->f_pos = realfile->f_pos;  in ovl_llseek()
286 static void ovl_file_modified(struct file *file)  in ovl_file_modified()  argument
289 	ovl_copyattr(file_inode(file));  in ovl_file_modified()
297 static void ovl_file_accessed(struct file *file)  in ovl_file_accessed()  argument
303 	if (file->f_flags & O_NOATIME)  in ovl_file_accessed()
306 	inode = file_inode(file);  in ovl_file_accessed()
322 	touch_atime(&file->f_path);  in ovl_file_accessed()
327 	struct file *file = iocb->ki_filp;  in ovl_read_iter()  local
328 	struct file *realfile;  in ovl_read_iter()
330 		.cred = ovl_creds(file_inode(file)->i_sb),  in ovl_read_iter()
337 	realfile = ovl_real_file(file);  in ovl_read_iter()
347 	struct file *file = iocb->ki_filp;  in ovl_write_iter()  local
348 	struct inode *inode = file_inode(file);  in ovl_write_iter()
349 	struct file *realfile;  in ovl_write_iter()
364 	realfile = ovl_real_file(file);  in ovl_write_iter()
385 static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,  in ovl_splice_read()
389 	struct file *realfile;  in ovl_splice_read()
415  * the real file.
417 static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,  in ovl_splice_write()
420 	struct file *realfile;  in ovl_splice_write()
449 static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)  in ovl_fsync()  argument
451 	struct dentry *dentry = file_dentry(file);  in ovl_fsync()
454 	struct file *upperfile;  in ovl_fsync()
458 	ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));  in ovl_fsync()
462 	/* Don't sync lower file for fear of receiving EROFS error */  in ovl_fsync()
468 	upperfile = ovl_real_file_path(file, &upperpath);  in ovl_fsync()
472 	old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fsync()
479 static int ovl_mmap(struct file *file, struct vm_area_struct *vma)  in ovl_mmap()  argument
481 	struct ovl_file *of = file->private_data;  in ovl_mmap()
483 		.cred = ovl_creds(file_inode(file)->i_sb),  in ovl_mmap()
490 static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)  in ovl_fallocate()  argument
492 	struct inode *inode = file_inode(file);  in ovl_fallocate()
493 	struct file *realfile;  in ovl_fallocate()
500 	ret = file_remove_privs(file);  in ovl_fallocate()
504 	realfile = ovl_real_file(file);  in ovl_fallocate()
509 	old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fallocate()
514 	ovl_file_modified(file);  in ovl_fallocate()
522 static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)  in ovl_fadvise()  argument
524 	struct file *realfile;  in ovl_fadvise()
528 	realfile = ovl_real_file(file);  in ovl_fadvise()
532 	old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_fadvise()
545 static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,  in ovl_copyfile()
546 			    struct file *file_out, loff_t pos_out,  in ovl_copyfile()
550 	struct file *realfile_in, *realfile_out;  in ovl_copyfile()
602 static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,  in ovl_copy_file_range()
603 				   struct file *file_out, loff_t pos_out,  in ovl_copy_file_range()
610 static loff_t ovl_remap_file_range(struct file *file_in, loff_t pos_in,  in ovl_remap_file_range()
611 				   struct file *file_out, loff_t pos_out,  in ovl_remap_file_range()
637 static int ovl_flush(struct file *file, fl_owner_t id)  in ovl_flush()  argument
639 	struct file *realfile;  in ovl_flush()
643 	realfile = ovl_real_file(file);  in ovl_flush()
648 		old_cred = ovl_override_creds(file_inode(file)->i_sb);  in ovl_flush()