Date: Fri, 30 Mar 2001 15:38:42 -0800 From: Kirk McKusick <mckusick@mckusick.com> To: Randell Jesup <rjesup@wgate.com> Cc: Bakul Shah <bakul@bitblocks.com>, arch@FreeBSD.ORG Subject: Re: Background Fsck Message-ID: <200103302338.PAA11228@beastie.mckusick.com> In-Reply-To: Your message of "30 Mar 2001 12:25:50 EST." <ybun1a3godd.fsf@jesup.eng.tvol.net.jesup.eng.tvol.net>
next in thread | previous in thread | raw e-mail | index | archive | help
As far as I can tell, you have gone through and listed every
error exit in fsck... Most of these can only arise if the logic
is broken in some fundamental way. For example:
errx(EEXIT, "BAD STATE %d FOR INODE I=%d",
can only occur if one of the states defined for an inode by
fsck is found. The state is derived from a classification made
in pass 1. If the inode has had random stuff put into it, then
it will be classified as USTATE. Similarly, inode numbers
that are out of bounds should have been discovered at a
higher level and dealt with (e.g., an out of bounds directory
entry should have been found and zapped). I do not disagree
that there may be some possibilities that slip through, but
going through and wholesale getting rid of error exits is
not the right approach. In general `fsck -p' will not fix
everything, but `fsck -y' should always succeed (though
success may be an empty filesystem).
Kirk
=-=-=-=-=-=-=-=
To: Kirk McKusick <mckusick@mckusick.com>
Cc: Bakul Shah <bakul@bitblocks.com>, arch@FreeBSD.ORG
Subject: Re: Background Fsck
From: Randell Jesup <rjesup@wgate.com>
Date: 30 Mar 2001 12:25:50 -0500
Kirk McKusick <mckusick@mckusick.com> writes:
> On a somewhat related note, I have always wondered if the
> current fsck algorithm can be significantly improved or if it
> is about as efficient as it can be (barring any peephole code
> improvements).
>
>Many improvements have been made to fsck over the years. Through
>there are undoubtedly more that could be made, there are no big
>easy improvements left.
Last time I checked, fsck basically calls exit() on a number of
types of errors (inode out of range was one of them I think - you had to
manually cleari for each one and restart fsck). I munged fsck to try
to recover a coworker's files when something went foobar in her 2.2.8
machine and wrote garbage across sectors all over her disk.
Does this fix those sorts of "I can't deal with it and won't try no
matter how hard you force me" cases?
>From the current source - I know that many of these are internal errors
that shouldn't happen, and are correct to exit out on. However, some
(like inoinfo(), ginode(), maybe getnextinode()) should NOT just cause
a blanket exit.
utilities.c: (This is the one that caused me the big trouble, I think)
-------
/*
* Look up state information for an inode.
*/
struct inostat *
inoinfo(inum)
ino_t inum;
{
static struct inostat unallocated = { USTATE, 0, 0 };
struct inostatlist *ilp;
int iloff;
if (inum > maxino)
errx(EEXIT, "inoinfo: inumber %d out of range", inum);
inode.c: (this may very well have been it too)
-------
/*
* General purpose interface for reading inodes.
*/
struct dinode *
ginode(inumber)
ino_t inumber;
{
ufs_daddr_t iblk;
if (inumber < ROOTINO || inumber > maxino)
errx(EEXIT, "bad inode number %d to ginode", inumber);
...
struct dinode *
getnextinode(inumber)
ino_t inumber;
{
long size;
ufs_daddr_t dblk;
static struct dinode *dp;
if (inumber != nextino++ || inumber > maxino)
errx(EEXIT, "bad inode number %d to nextinode", inumber);
...
void
setinodebuf(inum)
ino_t inum;
{
if (inum % sblock.fs_ipg != 0)
errx(EEXIT, "bad inode number %d to setinodebuf", inum);
...
getinoinfo(inumber):
errx(EEXIT, "cannot find inode %d", inumber);
...
default:
errx(EEXIT, "BAD STATE %d TO BLKERR", inoinfo(ino)->ino_state);
dir.c:
-------
if (idesc->id_type != DATA)
errx(EEXIT, "wrong type to dirscan %d", idesc->id_type);
pass2.c:
-------
default:
errx(EEXIT, "BAD STATE %d FOR ROOT INODE",
inoinfo(ROOTINO)->ino_state);
...
default:
errx(EEXIT, "BAD STATE %d FOR INODE I=%d",
inoinfo(dirp->d_ino)->ino_state, dirp->d_ino);
pass4.c:
-------
default:
errx(EEXIT, "BAD STATE %d FOR INODE I=%d",
inoinfo(inumber)->ino_state, inumber);
pass5.c:
-------
default:
inomapsize = blkmapsize = sumsize = 0; /* keep lint happy */
errx(EEXIT, "UNKNOWN ROTATIONAL TABLE FORMAT %d",
fs->fs_postblformat);
...
default:
if (j < ROOTINO)
break;
errx(EEXIT, "BAD STATE %d FOR INODE I=%ld",
inoinfo(j)->ino_state, j);
--
Randell Jesup, Worldgate Communications, ex-Scala, ex-Amiga OS team ('88-94)
rjesup@wgate.com
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200103302338.PAA11228>