It does not help modern compilers, and some may take some hit from it.
(I also found several functions that listed *every* of its 10 local vars with
"register" -- just how many free registers do people think machines have?)
in-core pointers to summary information. An array in this region
(fs_csp) could overflow on filesystems with a very large number of
cylinder groups (~16000 on i386 with 8k blocks). When this happens,
other fields in the superblock get corrupted, and fsck refuses to
check the filesystem.
Solve this problem by replacing the fs_csp array in 'struct fs'
with a single pointer, and add padding to keep the length of the
128-byte region fixed. Update the kernel and userland utilities
to use just this single pointer.
With this change, the kernel no longer makes use of the superblock
fields 'fs_csshift' and 'fs_csmask'. Add a comment to newfs/mkfs.c
to indicate that these fields must be calculated for compatibility
with older kernels.
Reviewed by: mckusick
mount_ifs: repocopy of sbin/mount, with most of the intelligence ripped out
and "ufs" replaced with "ifs" in the right places. It will only
mount a single filesystem, rather than the -t <type> magic that
our real mount does.
fsck_ifs: repocopy of sbin/fsck_ffs, but the directory structure stuff
(pass2 and some refcount checks) has been #ifdef'ed out.
src/sbin/Makefile: Build these two utilities
There is probably cruft code left in both which can be removed at a later
date, especially in mount_ifs, but I trust that people will not try
mount_ifs -a ..
Note: there are no man pages installed for these two commands as I haven't
actually written them yet.
effect on operation of fsck on filesystems without snapshots.
If you get compilation errors, be sure that you have copies of
/usr/include/sys/mount.h (1.94), /usr/include/sys/stat.h (1.21),
and /usr/include/ufs/ffs/fs.h (1.16) as of July 4, 2000 or later.
DIR I=64512 CONNECTED. PARENT WAS I=4032
fsck: cannot find inode 995904
fsdb found the inodes with no problem:
fsdb (inum: 64512)> inode 995904
current inode: directory
I=995904 MODE=40777 SIZE=512
MTIME=Feb 14 15:27:07 2000 [0 nsec]
CTIME=Feb 14 15:27:07 2000 [0 nsec]
ATIME=Feb 24 10:31:58 2000 [0 nsec]
OWNER=nobody GRP=nobody LINKCNT=4 FLAGS=0 BLKCNT=2 GEN=38a41386
Direct blocks: 8094568 0 0 0 0 0 0 0 0 0 0 0
Indirect blocks: 0 0 0
The problem turns out to be a program logic error in fsck. It stores
directory inodes internally in hash lists, using the number of
directories to form the hash key:
inpp = &inphead[inumber % numdirs];
Elsewhere, however, it increments numdirs when it finds unattached
directories. I've made the following fix, which solved the problem in
the case in hand.
Submitted by: Greg Lehey <grog@lemis.com>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Approved by: Kirk McKusick <mckusick@mckusick.com>
Submitted by: Kirk McKusick <mckusick@McKusick.COM>
Obtained from: Mckusick, BSDI and a host of others
This exactly matches Kirks sources imported under the
Tag MCKUSICK2. These are as supplied by kirk with one small
change needed to compile under freeBSD.
Some FreeBSD patches will be added back, though many have been
added to Kirk's sources already.
superblock is invalid, fsck looks at the label to help guess where
the next superblock should be. If the partition type is 4.2BSD,
fsck assumed that the block size was valid and divided by it, so
it dumped core if the size was 0.
Initialization of the label was broken almost 3 years ago in rev.1.9
of newfs/newfs.c. Newfs does not change the label at all, so there
is no problem (except the breakage of the automatic search for
backup superblocks) unless something else sets the partition type
to 4.2BSD. However, it is too easy to set partition types to
4.2.BSD by copying an old label or by using a disktab entry to
create the label.
PR: 2537
something closer to how we used to do it. The Lite2 way is to check the
"fsclean" flag in the superblock and stop there if so (during preen).
We now do the various superblock sanity checks that we used to do before
since it's cheap. We now get the filesystem state summary again instead
of "FILESYSTEM CLEAN; CHECKING SKIPPED" (or whatever).
