Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove two pieces of code (one disabled in revision 39665 and another derived
from the first one) that is not used for the last 12 years.

fix a comment typo

MFC after: 3 days

Fix a bug in gzipfs that prevented lseek() from working and add lseek()
support to bzip2fs. This fixes problems with loading compressed amd64
kernel modules containing debug symbols.

Submitted by: David Naylor naylor.b.david (gmail)
MFC after: 1 week

Fix logical bug in the bzip2 reading code, which results in bogus EIO
returned on a perfectly valid bzip2 stream whose decompressed size
is multiple of read-ahead buffer size. Reproduce the problem is easy:
create some power-of-two sized file (truncate -s 1m file will do),
bzip2 it and try to load it as md_image from loader. See how it fails.

The bug doesn't affect gzip code (which most of bzip2-reading code was
copied from) probably due to the fact that libgzip doesn't report
Z_STREAM_END with the last block, but requires extra call to inflate()
to retrieve it and has some extra data in the input stream at that time.
However, apply similar fix to gzipfs.c just in the case the API will
change in the future to do what bzip2 code does.

Add some ifdef'ed code to enable testing bzipfs.c from witin normal
FreeBSD environment as opposed to the restricted loader one, so that
one can use gdb and whatnot.

Sponsored by: Sippy Software, Inc., http://www.sippysoft.com/
MFC in: 7 days

Re-enable support for bzip2'ed compressed filesystems.

Clean up error handling in libstand filesystem code to be more consistent:
- bzipfs and gzipfs now properly return errno values directly from their
read routines rather than returning -1.
- missing errno values on error returns for the seek routines on almost
all filesystems were added.
- fstat() now returns -1 if an error occurs rather than ignoring it.
- nfs's readdir() routine now reports valid errno values if an error or
EOF occurs rather than EPERM (It was just returning 0 for success and
1 for failure).
- nullfs used the wrong semantics for every function besides close() and
seek(). Getting it right for close() appears to be an accident at that.
- read() for buffered files no longer returns 0 (EOF) if an error occurs,
but returns -1 instead.

(forced)

Splitfs is subject of:

MFC after: 2 weeks

Add splitfs vfs layer into libstand, which allows loading big kernels and
modules split across several physical medias. Following is how it works:

The splitfs code, when asked to open "foo" looks for a file "foo.split"
which is a text file containing a list of filenames and media names, e.g.

foo.aa "Kernel floppy 1"
foo.ab "Kernel floppy 2"
foo.ac "Kernel and modules floppy"

For each file segment, the process is:

- try to open the file
- prompt "Insert the disk labelled <whatever> and press any key..."
- try to open the file
- return error if file could not be located

RE team is free to use this feature in the upcoming 5.0-DP1.

Reviewed by: msmith, dcs

Complete bzip2-1.0.2 import.

MFC in: 14 days

Add __FBSDID()s to libstand

Add support for loading bzip2-compressed filesystems. Among other things
this would allow to load bzip2-compressed kernels/modules from the loader(8)
(support for that will be committer separately).

MFC after: 1 month