On Mon, Aug 09, 2021 at 08:12:37AM +0200, Christoph Hellwig wrote:
> Switch the dax_iomap_rw implementation to use iomap_iter.
>
> Signed-off-by: Christoph Hellwig <h...@lst.de>
/me gets excited about this file getting cleaned up
Reviewed-by: Darrick J. Wong <djw...@kernel.org>
--D
> ---
> fs/dax.c | 49 ++++++++++++++++++++++++-------------------------
> 1 file changed, 24 insertions(+), 25 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index 4d63040fd71f56..51da45301350a6 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1103,20 +1103,21 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct
> iomap *iomap)
> return size;
> }
>
> -static loff_t
> -dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
> - struct iomap *iomap, struct iomap *srcmap)
> +static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
> + struct iov_iter *iter)
> {
> + const struct iomap *iomap = &iomi->iomap;
> + loff_t length = iomap_length(iomi);
> + loff_t pos = iomi->pos;
> struct block_device *bdev = iomap->bdev;
> struct dax_device *dax_dev = iomap->dax_dev;
> - struct iov_iter *iter = data;
> loff_t end = pos + length, done = 0;
> ssize_t ret = 0;
> size_t xfer;
> int id;
>
> if (iov_iter_rw(iter) == READ) {
> - end = min(end, i_size_read(inode));
> + end = min(end, i_size_read(iomi->inode));
> if (pos >= end)
> return 0;
>
> @@ -1133,7 +1134,7 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t
> length, void *data,
> * written by write(2) is visible in mmap.
> */
> if (iomap->flags & IOMAP_F_NEW) {
> - invalidate_inode_pages2_range(inode->i_mapping,
> + invalidate_inode_pages2_range(iomi->inode->i_mapping,
> pos >> PAGE_SHIFT,
> (end - 1) >> PAGE_SHIFT);
> }
> @@ -1209,31 +1210,29 @@ ssize_t
> dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
> const struct iomap_ops *ops)
> {
> - struct address_space *mapping = iocb->ki_filp->f_mapping;
> - struct inode *inode = mapping->host;
> - loff_t pos = iocb->ki_pos, ret = 0, done = 0;
> - unsigned flags = 0;
> + struct iomap_iter iomi = {
> + .inode = iocb->ki_filp->f_mapping->host,
> + .pos = iocb->ki_pos,
> + .len = iov_iter_count(iter),
> + };
> + loff_t done = 0;
> + int ret;
>
> if (iov_iter_rw(iter) == WRITE) {
> - lockdep_assert_held_write(&inode->i_rwsem);
> - flags |= IOMAP_WRITE;
> + lockdep_assert_held_write(&iomi.inode->i_rwsem);
> + iomi.flags |= IOMAP_WRITE;
> } else {
> - lockdep_assert_held(&inode->i_rwsem);
> + lockdep_assert_held(&iomi.inode->i_rwsem);
> }
>
> if (iocb->ki_flags & IOCB_NOWAIT)
> - flags |= IOMAP_NOWAIT;
> + iomi.flags |= IOMAP_NOWAIT;
>
> - while (iov_iter_count(iter)) {
> - ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops,
> - iter, dax_iomap_actor);
> - if (ret <= 0)
> - break;
> - pos += ret;
> - done += ret;
> - }
> + while ((ret = iomap_iter(&iomi, ops)) > 0)
> + iomi.processed = dax_iomap_iter(&iomi, iter);
>
> - iocb->ki_pos += done;
> + done = iomi.pos - iocb->ki_pos;
> + iocb->ki_pos = iomi.pos;
> return done ? done : ret;
> }
> EXPORT_SYMBOL_GPL(dax_iomap_rw);
> @@ -1307,7 +1306,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault
> *vmf, pfn_t *pfnp,
> }
>
> /*
> - * Note that we don't bother to use iomap_apply here: DAX required
> + * Note that we don't bother to use iomap_iter here: DAX required
> * the file system block size to be equal the page size, which means
> * that we never have to deal with more than a single extent here.
> */
> @@ -1561,7 +1560,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault
> *vmf, pfn_t *pfnp,
> }
>
> /*
> - * Note that we don't use iomap_apply here. We aren't doing I/O, only
> + * Note that we don't use iomap_iter here. We aren't doing I/O, only
> * setting up a mapping, so really we're using iomap_begin() as a way
> * to look up our filesystem block.
> */
> --
> 2.30.2
>
