Remove copyright strings ifdef'd out

We've ifdef'd out the copyright strings for some time now. Go ahead and
remove the ifdefs. Plus whatever other detritis was left over from other
recent removals. These copyright strings are present in the comments and
are largely from CSRG's attempt at adding their copyright to every
binary file (which modern interpretations of the license doesn't
require).

Sponsored by: Netflix

sbin: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Delete snapshot after opening it when running fsck_ffs(9) in background.

When fsck_ffs(8) runs in background, it creates a snapshot named
fsck_snapshot in the filesystem's .snap directory. The fsck_snapshot
file was removed when the background fsck finished. If the system
crashed or the fsck exited unexpectedly, the fsck_snapshot file
would remain. The snapshot would consume ever more space as the
filesystem changed over time until it was removed by a system
administrator or a future run of background fsck removed it to
create a new snapshot file.

This commit unlinks the .snap/fsck_snapshot file immediately after
opening it so that it will be reclaimed when fsck closes it at the
conclusion of its run. After a system crash, it will be removed as
part of the filesystem cleanup because of its zero reference count.
As only a few milliseconds pass between its creation and unlinking,
there is far less opportunity for it to be accidentally left behind.

PR: 106107
MFC-after: 1 week

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Text format cleanups. No functional changes intended.

MFC-after: 1 week
Sponsored-by: The FreeBSD Foundation

Add the ability to adjust directory depths to background fsck_ffs(8).

Commit fe5e6e2 improved FFS directory placement when creating new
directories. It is done by keeping track of the depth of directories
in the filesystem and placing those lower in the tree closer together
while spreading out those higher in the tree.

Fsck_ffs(8) checks these depths and if incorrect adjusts them to
their correct value. When running in background fsck_ffs(8) needs
to be able to make an adjustment to the depth. This commit adds
the sysctl to make such an adjustment and adds the code to fsck_ffs(8)
to use the new sysctl.

MFC after: 1 week
Sponsored by: The FreeBSD Foundation

Skip Pass 5 in fsck_ffs(8) when corrupt cylinder groups remain unfixed.

Pass 1 of fsck_ffs checks the integrity of all the cylinder groups.
If any are found to have been corrupted it offers to rebuild them.
Pass 5 then makes a second pass over the cylinder groups to validate
their block and inode maps. Pass 5 assumes that the cylinder groups
are not corrupted and can segment fault if they are corrupted. Rather
than rerunning the corruption checks a second time in pass 5, this
fix keeps track whether any corrupt cylinder groups were found but not
fixed in pass 1 either due to running with the -n flag or by explicitly
answering `no' when asked whether to fix a corrupted cylinder group.
If any corrupted cylinder groups remain after pass 1, fsck_ffs will
decline to run pass 5. Instead it marks the filesystem as unclean
so that fsck_ffs will need to be run again before the filesystem can
be mounted.

This patch cleans up and documents the return value from check_cgmagic().
It also renames the variable / parameter "rebuildcg" to "rebuiltcg".
This parameter describes whether the cylinder group has been rebuilt
rather than whether it should be rebuilt.

Reported by: Chuck Silvers
Reviewed by: Chuck Silvers
MFC after: 1 week

Move the ability to search for alternate UFS superblocks from fsck_ffs(8)
into ffs_sbsearch() to allow use by other parts of the system.

Historically only fsck_ffs(8), the UFS filesystem checker, had code
to track down and use alternate UFS superblocks. Since fsdb(8) used
much of the fsck_ffs(8) implementation it had some ability to track
down alternate superblocks.

This change extracts the code to track down alternate superblocks
from fsck_ffs(8) and puts it into a new function ffs_sbsearch() in
sys/ufs/ffs/ffs_subr.c. Like ffs_sbget() and ffs_sbput() also found
in ffs_subr.c, these functions can be used directly by the kernel
subsystems. Additionally they are exported to the UFS library,
libufs(8) so that they can be used by user-level programs. The new
functions added to libufs(8) are sbfind(3) that is an alternative
to sbread(3) and sbsearch(3) that is an alternative to sbget(3).
See their manual pages for further details.

The utilities that have been changed to search for superblocks are
dumpfs(8), fsdb(8), ffsinfo(8), and fsck_ffs(8). Also, the prtblknos(8)
tool found in tools/diag/prtblknos searches for superblocks.

The UFS specific mount code uses the superblock search interface
when mounting the root filesystem and when the administrator doing
a mount(8) command specifies the force flag (-f). The standalone UFS
boot code (found in stand/libsa/ufs.c) uses the superblock search
code in the hope of being able to get the system up and running so
that fsck_ffs(8) can be used to get the filesystem cleaned up.

The following utilities have not been changed to search for
superblocks: clri(8), tunefs(8), snapinfo(8), fstyp(8), quot(8),
dump(8), fsirand(8), growfs(8), quotacheck(8), gjournal(8), and
glabel(8). When these utilities fail, they do report the cause of
the failure. The one exception is the tasting code used to try and
figure what a given disk contains. The tasting code will remain
silent so as not to put out a slew of messages as it trying to taste
every new mass storage device that shows up.

Reviewed by: kib
Reviewed by: Warner Losh
Tested by: Peter Holm
Differential Revision: https://reviews.freebsd.org/D36053
Sponsored by: The FreeBSD Foundation

Have fsck_ffs(8) properly correct superblock check-hash failures.

Part of the problem was that fsck_ffs would read the superblock
multiple times complaining and repairing the superblock check hash
each time and then at the end failing to write out the superblock
with the corrected check hash. This fix reads the superblock just
once and if the check hash is corrected ensures that the fixed
superblock gets written.

Tested by: Peter Holm
PR: 245916
MFC after: 1 week
Sponsored by: Netflix

Ensure that all allocated data structures in fsck_ffs are freed.

Several large data structures are allocated by fsck_ffs to track
resource usage. Most but not all were deallocated at the end of
checking each filesystem. This commit consolidates the freeing
of all data structures in one place and adds one that had previously
been missing.

It is important to clean up these data structures as they can be
large. If the previous allocations have not been freed, fsck_ffs
can run out of address space when many large filesystems are being
checked. An alternative would be to fork a new instance of fsck_ffs
for each filesystem to be checked, but we choose to free the small
set of large structures to save the fork overhead.

Reported by: Chuck Silvers
Tested by: Chuck Silvers
MFC after: 7 days
Sponsored by: Netflix

Rewrite the disk I/O management system in fsck_ffs(8). Other than
making fsck_ffs(8) run faster, there should be no functional change.

The original fsck_ffs(8) had its own disk I/O management system.
When gjournal(8) was added to FreeBSD 7, code was added to fsck_ffs(8)
to do the necessary gjournal rollback. Rather than use the existing
fsck_ffs(8) disk I/O system, it wrote its own from scratch. Similarly
when journalled soft updates were added in FreeBSD 9, code was added
to fsck_ffs(8) to do the necessary journal rollback. And once again,
rather than using either of the existing fsck_ffs(8) disk I/O
systems, it wrote its own from scratch. Lastly the fsdb(8) utility
uses the fsck_ffs(8) disk I/O management system. In preparation for
making the changes necessary to enable snapshots to be taken when
using journalled soft updates, it was necessary to have a single
disk I/O system used by all the various subsystems in fsck_ffs(8).

This commit merges the functionality required by all the different
subsystems into a single disk I/O system that supports all of their
needs. In so doing it picks up optimizations from each of them
with the results that each of the subsystems does fewer reads and
writes than it did with its own customized I/O system. It also
greatly simplifies making changes to fsck_ffs(8) since everything
goes through a single place. For example the ginode() function
fetches an inode from the disk. When inode check hashes were added,
they previously had to be checked in the code implementing inode
fetch in each of the three different disk I/O systems. Now they
need only be checked in ginode().

Tested by: Peter Holm
Sponsored by: Netflix

fsck_ffs/fsdb: fix -fno-common build

This one is also a small list:

- 3x duplicate definition (ufs2_zino, returntosingle, nflag)
- 5x 'needs extern', 3/5 of which are referenced in fsdb

-fno-common will become the default in GCC10/LLVM11.

MFC after: 1 week

This update eliminates a kernel stack disclosure bug in UFS/FFS
directory entries that is caused by uninitialized directory entry
padding written to the disk. It can be viewed by any user with read
access to that directory. Up to 3 bytes of kernel stack are disclosed
per file entry, depending on the the amount of padding the kernel
needs to pad out the entry to a 32 bit boundry. The offset in the
kernel stack that is disclosed is a function of the filename size.
Furthermore, if the user can create files in a directory, this 3
byte window can be expanded 3 bytes at a time to a 254 byte window
with 75% of the data in that window exposed. The additional exposure
is done by removing the entry, creating a new entry with a 4-byte
longer name, extracting 3 more bytes by reading the directory, and
repeating until a 252 byte name is created.

This exploit works in part because the area of the kernel stack
that is being disclosed is in an area that typically doesn't change
that often (perhaps a few times a second on a lightly loaded system),
and these file creates and unlinks themselves don't overwrite the
area of kernel stack being disclosed.

It appears that this bug originated with the creation of the Fast
File System in 4.1b-BSD (Circa 1982, more than 36 years ago!), and
is likely present in every Unix or Unix-like system that uses
UFS/FFS. Amazingly, nobody noticed until now.

This update also adds the -z flag to fsck_ffs to have it scrub
the leaked information in the name padding of existing directories.
It only needs to be run once on each UFS/FFS filesystem after a
patched kernel is installed and running.

Submitted by: David G. Lawrence <dg@dglawrence.com>
Reviewed by: kib
MFC after: 1 week

After a crash, a file that extends into indirect blocks may end up
shorter than its size resulting in a hole as its final block (which
is a violation of the invarients of the UFS filesystem).

Soft updates will always ensure that the file size is correct when
writing inodes to disk for files that contain only direct block
pointers. However soft updates does not roll back sizes for files
with indirect blocks that it has set to unallocated because their
contents have not yet been written to disk. Hence, the file can
appear to have a hole at its end because the block pointer has been
rolled back to zero when its inode was written to disk. Thus,
fsck_ffs calculates the last allocated block in the file. For files
that extend into indirect blocks, fsck_ffs checks for a size past
the last allocated block of the file and if that is found, shortens
the file to reference the last allocated block thus avoiding having
it reference a hole at its end.

Submitted by: Chuck Silvers <chs@netflix.com>
Tested by: Chuck Silvers <chs@netflix.com>
MFC after: 1 week
Sponsored by: Netflix

Include files missed in 329051.

Refactoring of reading and writing of the UFS/FFS superblock.
Specifically reading is done if ffs_sbget() and writing is done
in ffs_sbput(). These functions are exported to libufs via the
sbget() and sbput() functions which then used in the various
filesystem utilities. This work is in preparation for adding
subperblock check hashes.

No functional change intended.

Reviewed by: kib

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

fsck_ffs: Unsign some variables and make use of reallocarray(3).

Instead of casting listmax and numdirs to unsigned values just define
them as unsigned and avoid the casts. Use reallocarray(3).

While here, fs_ncg is already unsigned so the cast is unnecessary.

Reviewed by: mckusick
MFC after: 2 weeks

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Fsck_ufs was using an int rather than a ufs2_daddr_t to store the
alternate superblock location when given in the -b option. When int
is 32-bits, block numbers larger than 2^32 would get truncated. This
commit changes the storage fpr the alternate superblock location
to a ufs2_daddr_t.

Submitted by: Dmitry Sivachenko <trtrmitya@gmail.com>

Cleanup unnecessary semicolons from utilities we all love.

Fix a ton of speelling errors

arc lint is helpful

Reviewed By: allanjude, wblock, #manpages, chris@bsdjunk.com
Differential Revision: https://reviews.freebsd.org/D3337

Add globs.c, missed in r260068,260069

Submitted by: peter
Obtained from: Netflix
MFC after: 3 Days