Make a read splice from a DAX file go directly to direct_splice_read() to do the reading as filemap_splice_read() is unlikely to find any pagecache to splice. I think this affects only erofs, Ext2, Ext4, fuse and XFS. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Christoph Hellwig <hch@xxxxxx> cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> cc: Jens Axboe <axboe@xxxxxxxxx> cc: linux-erofs@xxxxxxxxxxxxxxxx cc: linux-ext4@xxxxxxxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx cc: linux-xfs@xxxxxxxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx cc: linux-block@xxxxxxxxxxxxxxx cc: linux-mm@xxxxxxxxx --- fs/splice.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/splice.c b/fs/splice.c index 1e0b7c7038b5..7b818b5b18d4 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -421,6 +421,11 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct kiocb kiocb; int ret; +#ifdef CONFIG_FS_DAX + if (IS_DAX(in->f_mapping->host)) + return direct_splice_read(in, ppos, pipe, len, flags); +#endif + iov_iter_pipe(&to, ITER_DEST, pipe, len); init_sync_kiocb(&kiocb, in); kiocb.ki_pos = *ppos;
