Commit 60392573 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Dave Chinner

direct-io: add flag to allow aio writes beyond i_size

Some filesystems can handle direct I/O writes beyond i_size safely,
so allow them to opt into receiving them.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 38dbfb59
......@@ -1194,13 +1194,19 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
}
/*
* For file extending writes updating i_size before data
* writeouts complete can expose uninitialized blocks. So
* even for AIO, we need to wait for i/o to complete before
* returning in this case.
* For file extending writes updating i_size before data writeouts
* complete can expose uninitialized blocks in dumb filesystems.
* In that case we need to wait for I/O completion even if asked
* for an asynchronous write.
*/
dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&
(end > i_size_read(inode)));
if (is_sync_kiocb(iocb))
dio->is_async = false;
else if (!(dio->flags & DIO_ASYNC_EXTEND) &&
(rw & WRITE) && end > i_size_read(inode))
dio->is_async = false;
else
dio->is_async = true;
dio->inode = inode;
dio->rw = rw;
......
......@@ -2527,6 +2527,9 @@ enum {
/* filesystem does not support filling holes */
DIO_SKIP_HOLES = 0x02,
/* filesystem can handle aio writes beyond i_size */
DIO_ASYNC_EXTEND = 0x04,
};
void dio_end_io(struct bio *bio, int error);
......
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