fuse: Switch to using async direct IO for FOPEN_DIRECT_IO

Switch to using the async directo IO code path in fuse_direct_read_iter()
and fuse_direct_write_iter().  This is especially important in connection
with loop devices with direct IO enabled as loop assumes async direct io is
actually async.

Signed-off-by: Martin Raiber <martin@urbackup.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index b2a4fab..383843c 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1436,10 +1436,26 @@ static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
        return res;
 }
 
+static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
+
 static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-       struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
-       return __fuse_direct_read(&io, to, &iocb->ki_pos);
+       ssize_t res;
+
+       if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
+               struct file *file = iocb->ki_filp;
+
+               if (is_bad_inode(file_inode(file)))
+                       return -EIO;
+
+               res = fuse_direct_IO(iocb, to);
+       } else {
+               struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
+
+               res = __fuse_direct_read(&io, to, &iocb->ki_pos);
+       }
+
+       return res;
 }
 
 static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
@@ -1454,8 +1470,14 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
        /* Don't allow parallel writes to the same file */
        inode_lock(inode);
        res = generic_write_checks(iocb, from);
-       if (res > 0)
-               res = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE);
+       if (res > 0) {
+               if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
+                       res = fuse_direct_IO(iocb, from);
+               } else {
+                       res = fuse_direct_io(&io, from, &iocb->ki_pos,
+                                            FUSE_DIO_WRITE);
+               }
+       }
        fuse_invalidate_attr(inode);
        if (res > 0)
                fuse_write_update_size(inode, iocb->ki_pos);