Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750789AbWHAX6i (ORCPT ); Tue, 1 Aug 2006 19:58:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750804AbWHAXxT (ORCPT ); Tue, 1 Aug 2006 19:53:19 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:18633 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S1750789AbWHAXxE (ORCPT ); Tue, 1 Aug 2006 19:53:04 -0400 Subject: [PATCH 28/28] honor r/w changes at do_remount() time To: linux-kernel@vger.kernel.org Cc: viro@ftp.linux.org.uk, herbert@13thfloor.at, hch@infradead.org, Dave Hansen From: Dave Hansen Date: Tue, 01 Aug 2006 16:53:01 -0700 References: <20060801235240.82ADCA42@localhost.localdomain> In-Reply-To: <20060801235240.82ADCA42@localhost.localdomain> Message-Id: <20060801235301.EBB58619@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2765 Lines: 83 Originally from: Herbert Poetzl This is the core of the read-only bind mount patch set. Note that this does _not_ add a "ro" option directly to the bind mount operation. If you require such a mount, you must first do the bind, then follow it up with a 'mount -o remount,ro' operation. Signed-off-by: Dave Hansen --- lxc-dave/fs/namespace.c | 24 ++++++++++++++++++++++-- lxc-dave/fs/open.c | 2 +- 2 files changed, 23 insertions(+), 3 deletions(-) diff -puN fs/namespace.c~C-D8-actually-add-flags fs/namespace.c --- lxc/fs/namespace.c~C-D8-actually-add-flags 2006-08-01 16:35:26.000000000 -0700 +++ lxc-dave/fs/namespace.c 2006-08-01 16:35:34.000000000 -0700 @@ -391,7 +391,7 @@ static int show_vfsmnt(struct seq_file * seq_path(m, mnt, mnt->mnt_root, " \t\n\\"); seq_putc(m, ' '); mangle(m, mnt->mnt_sb->s_type->name); - seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? " ro" : " rw"); + seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw"); for (fs_infop = fs_info; fs_infop->flag; fs_infop++) { if (mnt->mnt_sb->s_flags & fs_infop->flag) seq_puts(m, fs_infop->str); @@ -1014,6 +1014,23 @@ out: return err; } +static int change_mount_flags(struct vfsmount *mnt, int ms_flags) +{ + int error = 0; + int readonly_request = 0; + + if (ms_flags & MS_RDONLY) + readonly_request = 1; + if (readonly_request == __mnt_is_readonly(mnt)) + return 0; + + if (readonly_request) + error = mnt_make_readonly(mnt); + else + __mnt_unmake_readonly(mnt); + return error; +} + /* * change filesystem flags. dir should be a physical root of filesystem. * If you've mounted a non-root directory somewhere and want to do remount @@ -1035,7 +1052,10 @@ static int do_remount(struct nameidata * return -EINVAL; down_write(&sb->s_umount); - err = do_remount_sb(sb, flags, data, 0); + if (flags & MS_BIND) + err = change_mount_flags(nd->mnt, flags); + else + err = do_remount_sb(sb, flags, data, 0); if (!(sb->s_flags & MS_RDONLY)) mnt_flags |= MNT_SB_WRITABLE; if (!err) diff -puN fs/open.c~C-D8-actually-add-flags fs/open.c --- lxc/fs/open.c~C-D8-actually-add-flags 2006-08-01 16:35:30.000000000 -0700 +++ lxc-dave/fs/open.c 2006-08-01 16:35:34.000000000 -0700 @@ -546,7 +546,7 @@ asmlinkage long sys_faccessat(int dfd, c special_file(nd.dentry->d_inode->i_mode)) goto out_path_release; - if(IS_RDONLY(nd.dentry->d_inode)) + if(__mnt_is_readonly(nd.mnt) || IS_RDONLY(nd.dentry->d_inode)) res = -EROFS; out_path_release: _ - 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/