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 <ext-denis.2.karpov@xxxxxxxxx>
> ---
> 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 <linux/mount.h>
> #include <linux/log2.h>
> #include <linux/quotaops.h>
> +#include <linux/genhd.h>
> #include <asm/uaccess.h>
> #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
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