On Tue, Nov 26, 2019 at 01:20:51PM +0100, Johannes Thumshirn wrote:
> The 'start' variable indicates the start of a filemap and is set to the
> iocb's position, which we have already cached as 'pos', upon function
> entry.
>
> 'pos' is used as a cursor indicating the current position and updated
> later in iomap_dio_rw(), but not before the last use of 'start'.
>
> Remove 'start' as it's synonym for 'pos' before we're entering the loop
> calling iomapp_apply().
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Looks good to me,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/iomap/direct-io.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 1fc28c2da279..405456b12f03 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -397,7 +397,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> struct address_space *mapping = iocb->ki_filp->f_mapping;
> struct inode *inode = file_inode(iocb->ki_filp);
> size_t count = iov_iter_count(iter);
> - loff_t pos = iocb->ki_pos, start = pos;
> + loff_t pos = iocb->ki_pos;
> loff_t end = iocb->ki_pos + count - 1, ret = 0;
> unsigned int flags = IOMAP_DIRECT;
> bool wait_for_completion = is_sync_kiocb(iocb);
> @@ -451,14 +451,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> }
>
> if (iocb->ki_flags & IOCB_NOWAIT) {
> - if (filemap_range_has_page(mapping, start, end)) {
> + if (filemap_range_has_page(mapping, pos, end)) {
> ret = -EAGAIN;
> goto out_free_dio;
> }
> flags |= IOMAP_NOWAIT;
> }
>
> - ret = filemap_write_and_wait_range(mapping, start, end);
> + ret = filemap_write_and_wait_range(mapping, pos, end);
> if (ret)
> goto out_free_dio;
>
> @@ -469,7 +469,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> * pretty crazy thing to do, so we don't support it 100%.
> */
> ret = invalidate_inode_pages2_range(mapping,
> - start >> PAGE_SHIFT, end >> PAGE_SHIFT);
> + pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
> if (ret)
> dio_warn_stale_pagecache(iocb->ki_filp);
> ret = 0;
> --
> 2.16.4
>
