From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe Leroy Subject: [PATCH resending] splice: sendfile() at once fails for big files Date: Fri, 11 Jul 2014 14:09:47 +0200 (CEST) Message-ID: <20140711120947.5105B1A9740@localhost.localdomain> Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-crypto@vger.kernel.org To: Alexander Viro Return-path: Received: from pegase1.c-s.fr ([93.17.236.30]:49989 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751746AbaGKMcF (ORCPT ); Fri, 11 Jul 2014 08:32:05 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: When big files (over 64kbytes) are sent with sendfile(), they are sent by blocks of 64kbytes. In that case, the target must be informed that the current block is not the last one, otherwise if might take wrong actions. The issue was observed while sending a file to an AF_ALG socket for hashing. The hash was reset at each 64k block. This patch adds SPLICE_F_MORE to the flags when more data is pending. Signed-off-by: Christophe Leroy Index: b/fs/splice.c =================================================================== --- a/fs/splice.c +++ b/fs/splice.c @@ -1171,7 +1171,7 @@ long ret, bytes; umode_t i_mode; size_t len; - int i, flags; + int i, flags, more; /* * We require the input being a regular file, as we don't want to @@ -1214,6 +1214,7 @@ * Don't block on output, we have to drain the direct pipe. */ sd->flags &= ~SPLICE_F_NONBLOCK; + more = sd->flags & SPLICE_F_MORE; while (len) { size_t read_len; @@ -1226,6 +1227,10 @@ read_len = ret; sd->total_len = read_len; + if (read_len < len) + sd->flags |= SPLICE_F_MORE; + else if (!more) + sd->flags &= ~SPLICE_F_MORE; /* * NOTE: nonblocking mode only applies to the input. We * must not do the output in nonblocking mode as then we