MFC r260522, r260523, r261439, r261440, r261586, r264504, r264769, r265193,

    r265194, r265197

r260522:
Add the manual page for geom_uncompress(4).

r260523:
Build the geom_uncompress(4) module by default.

Fix geom_uncompress(4) module loading.  Don't link zlib.c (which is a module
itself) directly.

r261439:
Remove some unnecessary code.  The offsets read from the first block are
overwritten a few lines bellow.

r261440:
Fix a logic error.  Because of this inflateReset() wasn't being called and
the output buffer wasn't being cleared between the inflate() calls,
producing zeroed output after the first inflate() call.

This fixes the read of mkuzip(8) images with geom_uncompress(4).

r261586:
Fix the build with DEBUG enabled.  Where possible, fix style(9) issues.

r264504:
Make sure not to do I/O for more than MAXPHYS bytes. Doing so can cause
problems in our providers, such as a KASSERT in md(4). We can initiate
I/O for more than MAXPHYS bytes if we've been given a BIO for MAXPHYS
bytes, the blocks from which we're reading couldn't be compressed and
we had compression in preceeding blocks resulting in misalignment of
the blocks we're trying to read relative to the sector. We're forced to
round up the I/O length to make it an multiple of the sector size.

When we detect the condition, we'll reduce the block count and perform
a "short" read. In g_uzip_done() we need to consider the original I/O
length and stop early if we're about to deflate a block that we didn't
read. By using bio_completed in the cloned BIO and not bio_length to
check for this, we automatically and gracefully handle short reads that
our providers may be doing on top of the short reads we may initiate
ourselves.

r264769:
Keep geom_uncompress(4) in line with geom_uzip(4), bring in the r264504 fix.

Make sure not to start I/O bigger than MAXPHYS bytes.

r265193:
Some style and whitespace fixes.  Reduce the difference between geom_uzip(4)
and geom_uncompress(4).  Now, they produce an almost clean diff(1) output.

Remove a duplicated variable from g_uncompress.c and an unnecessary header
from g_uzip.c.

r265194:
Actually the FEATURE() macro is defined on sys/sysctl.h.

r265197:
Fix a leak in g_uzip_taste().  After retrieve all the block offsets from
the uzip image, free the last data read.

1 files changed, 107 insertions, 0 deletions

diff --git a/share/man/man4/geom_uncompress.4 b/share/man/man4/geom_uncompress.4
new file mode 100644
index 0000000..6e848d4
--- /dev/null
+++ b/share/man/man4/geom_uncompress.4
@@ -0,0 +1,107 @@
+.\" Copyright (c) 2014, Luiz Otavio O Souza <loos@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd January 9, 2014
+.Dt GEOM_UNCOMPRESS 4
+.Os
+.Sh NAME
+.Nm geom_uncompress
+.Nd "GEOM based compressed disk images"
+.Sh SYNOPSIS
+To compile this driver into the kernel, place the following line in your
+kernel configuration file:
+.Bd -ragged -offset indent
+.Cd "options GEOM_UNCOMPRESS"
+.Ed
+.Pp
+Alternatively, to load the driver as a module at boot time, place the
+following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+geom_uncompress_load="YES"
+.Ed
+.Sh DESCRIPTION
+The
+.Nm
+framework provides support for compressed read only disk images.
+This allows significant storage savings at the expense of a little CPU
+time on each read.
+Data written in the GEOM label area allows
+.Nm
+to detect compressed images which have been created with
+.Xr mkulzma 8
+or
+.Xr mkuzip 8
+and presented to the kernel as a logical disk device via
+.Xr md 4 .
+.Nm
+creates a unique
+.Pa md#.uncompress
+device for each image.
+.Pp
+The
+.Nm
+device is subsequently used by the
+.Fx
+kernel to access the disk images.
+The
+.Nm
+driver does not allow write operations to the underlying disk image.
+To check which
+.Xr md 4
+devices match a given
+.Nm
+device:
+.Bd -literal -offset indent
+# geom uncompress list
+Geom name: md0.uncompress
+Providers:
+1. Name: md0.uncompress
+   Mediasize: 52428800 (50M)
+   Sectorsize: 512
+   Mode: r1w0e0
+Consumers:
+1. Name: md0
+   Mediasize: 20864000 (20M)
+   Sectorsize: 512
+   Mode: r1w0e0
+.Ed
+.Sh SEE ALSO
+.Xr GEOM 4 ,
+.Xr md 4 ,
+.Xr geom 8 ,
+.Xr mkulzma 8 ,
+.Xr mkuzip 8
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+driver was written by
+.An "Maxim Sobolev" Aq sobomax@FreeBSD.org
+and
+.An "Aleksandr Rybalko" Aq ray@FreeBSD.org .
+This manual page was written by
+.An "Luiz Otavio O Souza" Aq loos@FreeBSD.org .