On 2021/9/16 14:23, Christoph Hellwig wrote:
On Wed, Sep 15, 2021 at 06:45:00PM +0800, Shiyang Ruan wrote:+static int +xfs_dax_write_iomap_end( + struct inode *inode, + loff_t pos, + loff_t length, + ssize_t written, + unsigned flags, + struct iomap *iomap) +{ + struct xfs_inode *ip = XFS_I(inode); + /* + * Usually we use @written to indicate whether the operation was + * successful. But it is always positive or zero. The CoW needs the + * actual error code from actor(). So, get it from + * iomap_iter->processed. + */ + const struct iomap_iter *iter = + container_of(iomap, typeof(*iter), iomap); + + if (!xfs_is_cow_inode(ip)) + return 0; + + if (iter->processed <= 0) { + xfs_reflink_cancel_cow_range(ip, pos, length, true); + return 0; + } + + return xfs_reflink_end_cow(ip, pos, iter->processed);Didn't we come to the conflusion last time that we don't actually need to poke into the iomap_iter here as the written argument is equal to iter->processed if it is > 0: if (iter->iomap.length && ops->iomap_end) { ret = ops->iomap_end(iter->inode, iter->pos, iomap_length(iter), iter->processed > 0 ? iter->processed : 0, iter->flags, &iter->iomap); .. So should be able to just do: static int xfs_dax_write_iomap_end( struct inode *inode, loff_t pos, loff_t length, ssize_t written, unsigned flags, struct iomap *iomap) { struct xfs_inode *ip = XFS_I(inode); if (!xfs_is_cow_inode(ip)) return 0; if (!written) { xfs_reflink_cancel_cow_range(ip, pos, length, true); return 0; } return xfs_reflink_end_cow(ip, pos, written); }
I see. Thanks for your guidance. -- Ruan
