fs/overlayfs/file.c

95 static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
102 	real->flags = 0;
103 	real->file = file->private_data;
119 	if (unlikely(file_inode(real->file) != d_inode(realpath.dentry))) {
120 		real->flags = FDPUT_FPUT;
121 		real->file = ovl_open_realfile(file, &realpath);
123 		return PTR_ERR_OR_ZERO(real->file);
127 	if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
128 		return ovl_change_flags(real->file, file->f_flags);
133 static int ovl_real_fdget(const struct file *file, struct fd *real)
136 		real->flags = 0;
137 		real->file = ovl_dir_real_file(file, false);
139 		return PTR_ERR_OR_ZERO(real->file);
142 	return ovl_real_fdget_meta(file, real, false);
187 	struct fd real;
192 	 * The two special cases below do not need to involve real fs,
203 	ret = ovl_real_fdget(file, &real);
209 	 * through copy up and modified on read/write, but only real
210 	 * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
212 	 * files, so we use the real file to perform seeks.
215 	real.file->f_pos = file->f_pos;
218 	ret = vfs_llseek(real.file, offset, whence);
221 	file->f_pos = real.file->f_pos;
224 	fdput(real);
266 	struct fd real;
277 	ret = ovl_real_fdget(file, &real);
281 	ret = backing_file_read_iter(real.file, iter, iocb, iocb->ki_flags,
283 	fdput(real);
292 	struct fd real;
308 	ret = ovl_real_fdget(file, &real);
320 	ret = backing_file_write_iter(real.file, iter, iocb, ifl, &ctx);
321 	fdput(real);
333 	struct fd real;
341 	ret = ovl_real_fdget(in, &real);
345 	ret = backing_file_splice_read(real.file, ppos, pipe, len, flags, &ctx);
346 	fdput(real);
354  * and file_start_write(real.file) in ovl_write_iter().
357  * the real file.
362 	struct fd real;
375 	ret = ovl_real_fdget(out, &real);
379 	ret = backing_file_splice_write(pipe, real.file, ppos, len, flags, &ctx);
380 	fdput(real);
390 	struct fd real;
398 	ret = ovl_real_fdget_meta(file, &real, !datasync);
403 	if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) {
405 		ret = vfs_fsync_range(real.file, start, end, datasync);
409 	fdput(real);
429 	struct fd real;
440 	ret = ovl_real_fdget(file, &real);
445 	ret = vfs_fallocate(real.file, mode, offset, len);
451 	fdput(real);
461 	struct fd real;
465 	ret = ovl_real_fdget(file, &real);
470 	ret = vfs_fadvise(real.file, offset, len, advice);
473 	fdput(real);
581 	struct fd real;
585 	err = ovl_real_fdget(file, &real);
589 	if (real.file->f_op->flush) {
591 		err = real.file->f_op->flush(real.file, id);
594 	fdput(real);