[PATCH 6/8] xfs: direct calls in the direct I/O path

[Christoph Hellwig <hch@xxxxxx>]

We control both the callers and callees of ->direct_IO, so remove the
indirect calls.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/xfs/xfs_aops.c | 24 +++++-------------------
 fs/xfs/xfs_aops.h |  3 +++
 fs/xfs/xfs_file.c | 17 +++++++++++++++--
 3 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 80714eb..b368277 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1303,7 +1303,7 @@ xfs_get_blocks_dax_fault(
  * whereas if we have flags set we will always be called in task context
  * (i.e. from a workqueue).
  */
-STATIC int
+int
 xfs_end_io_direct_write(
        struct kiocb            *iocb,
        loff_t                  offset,
@@ -1374,24 +1374,10 @@ xfs_vm_direct_IO(
        struct kiocb            *iocb,
        struct iov_iter         *iter)
 {
-       struct inode            *inode = iocb->ki_filp->f_mapping->host;
-       dio_iodone_t            *endio = NULL;
-       int                     flags = 0;
-       struct block_device     *bdev;
-
-       if (iov_iter_rw(iter) == WRITE) {
-               endio = xfs_end_io_direct_write;
-               flags = DIO_ASYNC_EXTEND;
-       }
-
-       if (IS_DAX(inode)) {
-               return dax_do_io(iocb, inode, iter,
-                                xfs_get_blocks_direct, endio, 0);
-       }
-
-       bdev = xfs_find_bdev_for_inode(inode);
-       return  __blockdev_direct_IO(iocb, inode, bdev, iter,
-                       xfs_get_blocks_direct, endio, NULL, flags);
+       /*
+        * We just need the method present so that open/fcntl allow direct I/O.
+        */
+       return -EINVAL;
 }
 
 STATIC sector_t
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index 814aab7..bf2d9a1 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -60,6 +60,9 @@ int   xfs_get_blocks_direct(struct inode *inode, sector_t 
offset,
 int    xfs_get_blocks_dax_fault(struct inode *inode, sector_t offset,
                                 struct buffer_head *map_bh, int create);
 
+int    xfs_end_io_direct_write(struct kiocb *iocb, loff_t offset,
+               ssize_t size, void *private);
+
 extern void xfs_count_page_state(struct page *, int *, int *);
 extern struct block_device *xfs_find_bdev_for_inode(struct inode *);
 
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index f761f49..24b267d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -317,7 +317,13 @@ xfs_file_dio_aio_read(
        }
 
        data = *to;
-       ret = mapping->a_ops->direct_IO(iocb, &data);
+       if (IS_DAX(inode)) {
+               ret = dax_do_io(iocb, inode, &data, xfs_get_blocks_direct,
+                               NULL, 0);
+       } else {
+               ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data,
+                               xfs_get_blocks_direct, NULL, NULL, 0);
+       }
        if (ret > 0) {
                iocb->ki_pos += ret;
                iov_iter_advance(to, ret);
@@ -650,7 +656,14 @@ xfs_file_dio_aio_write(
        trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
 
        data = *from;
-       ret = mapping->a_ops->direct_IO(iocb, &data);
+       if (IS_DAX(inode)) {
+               ret = dax_do_io(iocb, inode, &data, xfs_get_blocks_direct,
+                               xfs_end_io_direct_write, 0);
+       } else {
+               ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data,
+                               xfs_get_blocks_direct, xfs_end_io_direct_write,
+                               NULL, DIO_ASYNC_EXTEND);
+       }
 
        /* see generic_file_direct_write() for why this is necessary */
        if (mapping->nrpages) {
-- 
2.1.4