On Tue, Sep 03, 2019 at 03:03:26PM +0200, Christoph Hellwig wrote:
> From: Matthew Bobrowski <mbobrowski@xxxxxxxxxxxxxx>
>
> Modify the calling convention for the iomap_dio_rw ->end_io() callback.
> Rather than passing either dio->error or dio->size as the 'size' argument,
> instead pass both the dio->error and the dio->size value separately.
>
> In the instance that an error occurred during a write, we currently cannot
> determine whether any blocks have been allocated beyond the current EOF and
> data has subsequently been written to these blocks within the ->end_io()
> callback. As a result, we cannot judge whether we should take the truncate
> failed write path. Having both dio->error and dio->size will allow us to
> perform such checks within this callback.
>
> Signed-off-by: Matthew Bobrowski <mbobrowski@xxxxxxxxxxxxxx>
> [hch: minor cleanups]
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/iomap/direct-io.c | 9 +++------
> fs/xfs/xfs_file.c | 8 +++++---
> include/linux/iomap.h | 4 ++--
> 3 files changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 10517cea9682..2ccf1c6460d4 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -77,13 +77,10 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio)
> loff_t offset = iocb->ki_pos;
> ssize_t ret;
>
> - if (dio->end_io) {
> - ret = dio->end_io(iocb,
> - dio->error ? dio->error : dio->size,
> - dio->flags);
> - } else {
> + if (dio->end_io)
> + ret = dio->end_io(iocb, dio->size, dio->error, dio->flags);
> + else
> ret = dio->error;
> - }
>
> if (likely(!ret)) {
> ret = dio->size;
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index d952d5962e93..3d8e6db9ef77 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -370,21 +370,23 @@ static int
> xfs_dio_write_end_io(
> struct kiocb *iocb,
> ssize_t size,
> + int error,
> unsigned flags)
> {
> struct inode *inode = file_inode(iocb->ki_filp);
> struct xfs_inode *ip = XFS_I(inode);
> loff_t offset = iocb->ki_pos;
> unsigned int nofs_flag;
> - int error = 0;
>
> trace_xfs_end_io_direct_write(ip, offset, size);
>
> if (XFS_FORCED_SHUTDOWN(ip->i_mount))
> return -EIO;
>
> - if (size <= 0)
> - return size;
> + if (error)
> + return error;
> + if (!size)
> + return 0;
>
> /*
> * Capture amount written on completion as we can't reliably account
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index bc499ceae392..50bb746d2216 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -188,8 +188,8 @@ sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
> */
> #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
> #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
> -typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
> - unsigned flags);
> +typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t size, int error,
> + unsigned int flags);
> ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> const struct iomap_ops *ops, iomap_dio_end_io_t end_io);
> int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
> --
> 2.20.1
>
