xfs
[Top] [All Lists]

[PATCH 5/6] xfs: add DAX IO path support

To: xfs@xxxxxxxxxxx
Subject: [PATCH 5/6] xfs: add DAX IO path support
From: Dave Chinner <david@xxxxxxxxxxxxx>
Date: Wed, 4 Mar 2015 10:30:26 +1100
Cc: linux-fsdevel@xxxxxxxxxxxxxxx, jack@xxxxxxx, willy@xxxxxxxxxxxxxxx
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <1425425427-16283-1-git-send-email-david@xxxxxxxxxxxxx>
References: <1425425427-16283-1-git-send-email-david@xxxxxxxxxxxxx>
From: Dave Chinner <dchinner@xxxxxxxxxx>

DAX does not do buffered IO (can't buffer direct access!) and hence
all read/write IO is vectored through the direct IO path.  Hence we
need to add the DAX IO path callouts to the direct IO
infrastructure.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 fs/xfs/xfs_aops.c | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 22cb03a..28b79c5 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1558,6 +1558,30 @@ xfs_end_io_direct_write(
        }
 }
 
+static inline ssize_t
+xfs_vm_do_dio(
+       struct inode            *inode,
+       int                     rw,
+       struct kiocb            *iocb,
+       struct iov_iter         *iter,
+       loff_t                  offset,
+       void                    (*endio)(struct kiocb   *iocb,
+                                        loff_t         offset,
+                                        ssize_t        size,
+                                        void           *private),
+       int                     flags)
+{
+       struct block_device     *bdev;
+
+       if (IS_DAX(inode))
+               return dax_do_io(rw, iocb, inode, iter, offset,
+                                xfs_get_blocks_direct, endio, 0);
+
+       bdev = xfs_find_bdev_for_inode(inode);
+       return  __blockdev_direct_IO(rw, iocb, inode, bdev, iter, offset,
+                                    xfs_get_blocks_direct, endio, NULL, flags);
+}
+
 STATIC ssize_t
 xfs_vm_direct_IO(
        int                     rw,
@@ -1566,17 +1590,12 @@ xfs_vm_direct_IO(
        loff_t                  offset)
 {
        struct inode            *inode = iocb->ki_filp->f_mapping->host;
-       struct block_device     *bdev = xfs_find_bdev_for_inode(inode);
 
        if (rw & WRITE) {
-               return __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
-                                           offset, xfs_get_blocks_direct,
-                                           xfs_end_io_direct_write, NULL,
-                                           DIO_ASYNC_EXTEND);
+               return xfs_vm_do_dio(inode, rw, iocb, iter, offset,
+                                    xfs_end_io_direct_write, DIO_ASYNC_EXTEND);
        }
-       return __blockdev_direct_IO(rw, iocb, inode, bdev, iter,
-                                   offset, xfs_get_blocks_direct,
-                                   NULL, NULL, 0);
+       return xfs_vm_do_dio(inode, rw, iocb, iter, offset, NULL, 0);
 }
 
 /*
-- 
2.0.0

<Prev in Thread] Current Thread [Next in Thread>