From: Pavel Machek Subject: Re: [PATCH 4/4] EXT2: add 'notify' mount option Date: Wed, 10 Jun 2009 23:03:13 +0200 Message-ID: <20090610210313.GD1381@ucw.cz> References: <60607de38c1ebbd1ba1cb33d85f1dcdec77f3c61.1244049681.git.ext-denis.2.karpov@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: axboe@kernel.dk, akpm@linux-foundation.org, hirofumi@mail.parknet.co.jp, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, adrian.hunter@nokia.com, artem.bityutskiy@nokia.com, tytso@mit.edu To: Denis Karpov Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:46352 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757859AbZFJVDV (ORCPT ); Wed, 10 Jun 2009 17:03:21 -0400 Content-Disposition: inline In-Reply-To: <60607de38c1ebbd1ba1cb33d85f1dcdec77f3c61.1244049681.git.ext-denis.2.karpov@nokia.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed 2009-06-03 18:05:18, Denis Karpov wrote: > Implement EXT2 fs mount option 'notify'. The effect of this option > is that a notification is sent to userspace on errors that indicate > filesystem damage/inconsistency. Generic filesystem corruption > notification mechnism is used. By the time you start checking volume, you may have already damaged data, right? (Imagine two inodes pointing to same block, lets say /etc/shadow and /tmp/foo. Writes to /tmp/foo will now kill your passwords. fsck would duplicate the blocks, but I do not think internal checking in ext2 would catch it soon enough). > Signed-off-by: Denis Karpov > --- > fs/ext2/super.c | 15 ++++++++++++++- > include/linux/ext2_fs.h | 2 +- > 2 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/fs/ext2/super.c b/fs/ext2/super.c > index 5c4afe6..04802cd 100644 > --- a/fs/ext2/super.c > +++ b/fs/ext2/super.c > @@ -32,6 +32,7 @@ > #include > #include > #include > +#include > #include > #include "ext2.h" > #include "xattr.h" > @@ -68,6 +69,8 @@ void ext2_error (struct super_block * sb, const char * function, > printk("Remounting filesystem read-only\n"); > sb->s_flags |= MS_RDONLY; > } > + if (test_opt(sb, ERR_NOTIFY)) > + notify_part_fs_unclean(part_to_dev(sb->s_bdev->bd_part), 1); > } > > void ext2_warning (struct super_block * sb, const char * function, > @@ -81,6 +84,8 @@ void ext2_warning (struct super_block * sb, const char * function, > vprintk(fmt, args); > printk("\n"); > va_end(args); > + if (test_opt(sb, ERR_NOTIFY)) > + notify_part_fs_unclean(part_to_dev(sb->s_bdev->bd_part), 1); > } > > void ext2_update_dynamic_rev(struct super_block *sb) > @@ -289,6 +294,9 @@ static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) > if (!test_opt(sb, RESERVATION)) > seq_puts(seq, ",noreservation"); > > + if (!test_opt(sb, ERR_NOTIFY)) > + seq_puts(seq, ",notify"); > + > return 0; > } > > @@ -391,7 +399,8 @@ enum { > Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, > Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, > Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, > - Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation > + Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation, > + Opt_err_notify, > }; > > static const match_table_t tokens = { > @@ -425,6 +434,7 @@ static const match_table_t tokens = { > {Opt_usrquota, "usrquota"}, > {Opt_reservation, "reservation"}, > {Opt_noreservation, "noreservation"}, > + {Opt_err_notify, "notify"}, > {Opt_err, NULL} > }; > > @@ -565,6 +575,9 @@ static int parse_options (char * options, > clear_opt(sbi->s_mount_opt, RESERVATION); > printk("reservations OFF\n"); > break; > + case Opt_err_notify: > + set_opt(sbi->s_mount_opt, ERR_NOTIFY); > + break; > case Opt_ignore: > break; > default: > diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h > index 121720d..ecec20b 100644 > --- a/include/linux/ext2_fs.h > +++ b/include/linux/ext2_fs.h > @@ -347,7 +347,7 @@ struct ext2_inode { > #define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */ > #define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */ > #define EXT2_MOUNT_RESERVATION 0x080000 /* Preallocation */ > - > +#define EXT2_MOUNT_ERR_NOTIFY 0x100000 /* Error notifications */ > > #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt > #define set_opt(o, opt) o |= EXT2_MOUNT_##opt -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html