> > +/* > > + * @bdev_in: source block device > > + * @pos_in: source offset > > + * @bdev_out: destination block device > > + * @pos_out: destination offset > > + * @len: length in bytes to be copied > > + * @endio: endio function to be called on completion of copy operation, > > + * for synchronous operation this should be NULL > > + * @private: endio function will be called with this private data, should be > > + * NULL, if operation is synchronous in nature > > + * @gfp_mask: memory allocation flags (for bio_alloc) > > + * > > + * Returns the length of bytes copied or error if encountered > > + * > > + * Description: > > + * Copy source offset from source block device to destination block > > + * device. Max total length of copy is limited to MAX_COPY_TOTAL_LENGTH > > + */ > > +int blkdev_issue_copy(struct block_device *bdev_in, loff_t pos_in, > > I'd have thought you'd return ssize_t here. If the two block devices > are loopmounted xfs files, we can certainly reflink "copy" more than 2GB > at a time. > > --D > Sure we will add this to make API future proof, but at present we do have a limit for copy. COPY_MAX_BYTES(=128MB) at present. This limit is based on our internal testing, we have plans to increase/remove with this limit in future phases. Thank you, Nitesh Shetty
