Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762838AbYBHWcB (ORCPT ); Fri, 8 Feb 2008 17:32:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759271AbYBHW1K (ORCPT ); Fri, 8 Feb 2008 17:27:10 -0500 Received: from e32.co.us.ibm.com ([32.97.110.150]:36312 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758536AbYBHW1G (ORCPT ); Fri, 8 Feb 2008 17:27:06 -0500 Subject: [RFC][PATCH 09/30] r/o bind mounts: drop write during emergency remount To: linux-kernel@vger.kernel.org Cc: hch@lst.de, viro@ZenIV.linux.org.uk, viro@ftp.linux.org.uk, miklos@szeredi.hu, Dave Hansen From: Dave Hansen Date: Fri, 08 Feb 2008 14:26:58 -0800 References: <20080208222641.6024A7CC@kernel> In-Reply-To: <20080208222641.6024A7CC@kernel> Message-Id: <20080208222658.3CF9608F@kernel> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1699 Lines: 60 The emergency remount code forcibly removes FMODE_WRITE from filps. The r/o bind mount code notices that this was done without a proper mnt_drop_write() and properly gives a warning. This patch does a mnt_drop_write() to keep everything balanced. Signed-off-by: Dave Hansen --- linux-2.6.git-dave/fs/super.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff -puN fs/super.c~robind-sysrq-fix fs/super.c --- linux-2.6.git/fs/super.c~robind-sysrq-fix 2008-02-08 13:04:48.000000000 -0800 +++ linux-2.6.git-dave/fs/super.c 2008-02-08 13:04:49.000000000 -0800 @@ -37,6 +37,7 @@ #include #include #include +#include #include @@ -566,10 +567,25 @@ static void mark_files_ro(struct super_b { struct file *f; +retry: file_list_lock(); list_for_each_entry(f, &sb->s_files, f_u.fu_list) { - if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f)) - f->f_mode &= ~FMODE_WRITE; + struct vfsmount *mnt; + if (!S_ISREG(f->f_path.dentry->d_inode->i_mode)) + continue; + if (!file_count(f)) + continue; + if (!(f->f_mode & FMODE_WRITE)) + continue; + f->f_mode &= ~FMODE_WRITE; + mnt = f->f_path.mnt; + file_list_unlock(); + /* + * This can sleep, so we can't hold + * the file_list_lock() spinlock. + */ + mnt_drop_write(mnt); + goto retry; } file_list_unlock(); } _ -- 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/