Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752019AbbDLRJB (ORCPT ); Sun, 12 Apr 2015 13:09:01 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:7410 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbbDLRIk (ORCPT ); Sun, 12 Apr 2015 13:08:40 -0400 From: Dmitry Monakhov To: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, Dmitry Monakhov Subject: [PATCH 1/2] pipe: fix race with fcntl Date: Sun, 12 Apr 2015 21:08:21 +0400 Message-Id: <1428858502-5371-2-git-send-email-dmonakhov@openvz.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1428858502-5371-1-git-send-email-dmonakhov@openvz.org> References: <1428858502-5371-1-git-send-email-dmonakhov@openvz.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2636 Lines: 87 Fix other long standing issues caused by fcntl(,F_SETFL,): - User can disable O_DIRECT for pipe[1] (paketized IO), but can not enable it again. - Currently we do not set O_APPEND on pipe[1] (IMHO it is wrong, but let it be) so it is reasonable to completely prohibit change O_APPEND flag on both end's of pipe. Add ->check_flags method in order to diallow O_APPEND toggling. Signed-off-by: Dmitry Monakhov --- fs/fcntl.c | 6 ++++-- fs/pipe.c | 16 +++++++++++++--- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/fs/fcntl.c b/fs/fcntl.c index ee85cd4..0bdc9c7 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -51,9 +51,11 @@ static int setfl(int fd, struct file * filp, unsigned long arg) if (arg & O_NDELAY) arg |= O_NONBLOCK; + /* allowed only for inodes with ->direct_io method or write pipe */ if (arg & O_DIRECT) { - if (!filp->f_mapping || !filp->f_mapping->a_ops || - !filp->f_mapping->a_ops->direct_IO) + if ((!filp->f_mapping || !filp->f_mapping->a_ops || + !filp->f_mapping->a_ops->direct_IO) && + !(get_pipe_info(filp) && (filp->f_flags | O_WRONLY))) return -EINVAL; } diff --git a/fs/pipe.c b/fs/pipe.c index 8865f79..0c15647 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -329,9 +329,9 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) return ret; } -static inline int is_packetized(struct file *file) +static inline int is_packetized(struct kiocb *iocb) { - return (file->f_flags & O_DIRECT) != 0; + return (iocb->ki_flags & IOCB_DIRECT) != 0; } static ssize_t @@ -427,7 +427,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) buf->offset = 0; buf->len = copied; buf->flags = 0; - if (is_packetized(filp)) { + if (is_packetized(iocb)) { buf->ops = &packet_pipe_buf_ops; buf->flags = PIPE_BUF_FLAG_PACKET; } @@ -943,6 +943,15 @@ err: return ret; } +/* XXX: Currently it is not possible distinguish read side from write one */ +static int pipe_check_flags(int flags) +{ + if (flags & O_APPEND) + return -EINVAL; + + return 0; +} + const struct file_operations pipefifo_fops = { .open = fifo_open, .llseek = no_llseek, @@ -952,6 +961,7 @@ const struct file_operations pipefifo_fops = { .unlocked_ioctl = pipe_ioctl, .release = pipe_release, .fasync = pipe_fasync, + .check_flags = pipe_check_flags, }; /* -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/