Commit Graph

1081 Commits

Author SHA1 Message Date
Brian Behlendorf
f706421173 Correctly return ERANGE in getxattr(2)
According to the getxattr(2) man page the ERANGE errno should be
returned when the size of the value buffer is to small to hold the
result.  Prior to this patch the implementation would just truncate
the value to size bytes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1408
2013-04-24 12:35:04 -07:00
Chris Dunlop
254255f735 Trivial spelling fix
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1411
2013-04-19 15:43:16 -07:00
Caleb James DeLisle
8f1e11b610 Remove .readdir from zpl_file_operations table
The zpl_readdir() function shouldn't be registered as part of
the zpl_file_operations table, it must only be part of the
zpl_dir_file_operations table.  By removing this callback
the VFS will now correctly return ENOTDIR when calling
getdents() on a file.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1404
2013-04-19 15:36:47 -07:00
Martin Matuska
b28e57cb82 Allow setting a lower ashift with -o ashift
Previous patches have allowed you to set an increased ashift to
avoid doing 512b IO with 4k sector devices.  However, it was not
possible to set the ashift lower than the reported physical sector
size even when a smaller logical size was supported.  In practice,
there are several cases where settong a lower ashift is useful:

* Most modern drives now correctly report their physical sector
  size as 4k.  This causes zfs to correctly default to using a 4k
  sector size (ashift=12).  However, for some usage models this
  new default ashift value causes an unacceptable increase in
  space usage.  Filesystems with many small files may see the
  total available space reduced to 30-40% which is unacceptable.

* When replacing a drive in an existing pool which was created
  with ashift=9 a modern 4k sector drive cannot be used.  The
  'zpool replace' command will issue an error that the new drive
  has an 'incompatible sector alignment'.  However, by allowing
  the ashift to be manual specified as smaller, non-optimal,
  value the device may still be safely used.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1381
Closes #1328
Issue #967
Issue #548
2013-04-12 10:50:46 -07:00
George Wilson
295304bed6 Illumos #3422, #3425
3422 zpool create/syseventd race yield non-importable pool
3425 first write to a new zvol can fail with EFBIG

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  illumos/illumos-gate@bda8819455
  https://www.illumos.org/issues/3422
  https://www.illumos.org/issues/3425

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1390
2013-04-12 09:01:36 -07:00
Brian Behlendorf
9d248f73a4 Add additional dependencies for DKMS package
For the DKMS package to successfully build the kernel-devel
headers must be included along gcc, make, and perl.  The ZFS
code never directly invokes perl but the kernel build system
depends on it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1380
2013-04-02 16:06:02 -07:00
Brian Behlendorf
d17eeafbf0 Replace the ZFS_AC_META perl dependency with awk
The only remaining perl dependency is part of the ZFS_AC_META macro.
By eliminating this and replacing it with awk we can avoid the need
to pull in perl to rebuild the packages.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1380
2013-04-02 16:05:45 -07:00
Brian Behlendorf
c8122d2504 Only require spl-devel-kmod = %{version}
Commit f6fb7651a0 introduced the idea
of working builds which work correctly.  However, because the zfs-kmod
depends on a specific 'spl-devel-kmod = {version}-%{release}' package
and the release component is unique the dependency is never satisfied.

This requires line was introduced to ensure the correct version of the
spl is always used.  In this context only the version number is required
so the release component has been dropped to satisfy the dependency.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 16:05:45 -07:00
Brian Behlendorf
5b5a65b022 Automake 1.10.1 compat: AM_SILENT_RULES
Part of the automated testing involves building the source on Debian Lenny
which ships an ancient version of automake (1.10.1).  Historically, this
has caused a non-fatal warning about AM_SILENT_RULES not being defined.
But when the autogen.sh script was updated to use autoreconf the warning
became fatal.

  configure.ac:31: warning: macro `AM_SILENT_RULES' not found in library
  autoreconf: running: /usr/bin/autoconf --force
  configure.ac:34: error: possibly undefined macro: AM_SILENT_RULES
        If this token and others are legitimate, please use m4_pattern_allow.

To resolve this build issue the call to AM_SILENT_RULES has been wrapped
by m4_ifdef().  This prevents the macro from being expanded on platforms
where it's undefined.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 16:05:45 -07:00
Jan Engelhardt
8c39262945 build: do not call boilerplate ourself
Rationale see section 3.5 "Using `autoreconf' to Update `configure'
Scripts" of the autoconf manual.

http://www.gnu.org/software/autoconf/manual/autoconf-2.67/html_node/autoreconf-Invocation.html

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 10:55:20 -07:00
Jan Engelhardt
ea0fcfc875 gitignore: anchor entries at their respective directory
.ko is specific to module, .m4 to config, etc.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 10:50:17 -07:00
Jan Engelhardt
ecf76e3676 build: use CPPFLAGS
-D and -I are preprocessor flags, so should preferably be in the
appropriate variable.

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 10:48:26 -07:00
Jan Engelhardt
4e95cc99b0 build: resolve orthographic and other grammatical errors
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-04-02 10:44:52 -07:00
Turbo Fredriksson
4a5b121808 Man page updates for SMB
* Update manpage with more information about the ACL, guest access
  and that samba needs to be able to authenticate user(s).
* Add information that 'net' can be used to modify the share after
  ZFS sharing and that it will be undone with a 'zfs unshare'.
* Give an example on how to mount a SMB filesystem shared via ZFS.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1181
Issue #1170
2013-04-02 10:36:25 -07:00
Turbo Fredriksson
be8bc8c0d3 Add smb_available() sanity checks
Do basic sanity checks in smb_available() to verify that the 'net'
command and the usershare directory exists.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1124
2013-04-02 09:27:52 -07:00
Nick Garvey
b5d8c5fb08 Correct typos in renaming example
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1373
2013-04-02 09:24:39 -07:00
Brian Behlendorf
36c0b62799 Tag zfs-0.6.1
META file and release log updated.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-26 08:50:29 -07:00
Brian Behlendorf
b7f59425f9 Include init scripts in packages
The distribution specific init scripts where excluded from the
packaging when it was reworked.  The intention is to replace
them with systemd equivilants.  However, that work has not yet
been done and the init scripts are still useful so they have
been added back in to the packaging.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-26 08:50:09 -07:00
Brian Behlendorf
0df23ca9a1 Provide ${kmodname}-devel-kmod for yum-builddep
In order to ensure that yum-builddep pulls in all the build
requirements a generic ${kmodname}-devel-kmod provides line is
added.  This allows a version of the development headers to be
included without requiring knowledge of the kernel version.

This is important because unlike rpmbuild which does correctly
expand the source rpm spec file, yum-builddep does not.  Without
this generic provides line mock which relies on yum-builddep is
unable to automatically satisfy the dependency.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-25 13:28:19 -07:00
Brian Behlendorf
f6fb7651a0 Use 'git describe' for working builds
When building from an arbitrary commit in the git tree it's useful
for the resulting packages to be uniquely identifiable.  Therefore,
the build system has been updated to detect if your compiling in
git tree.

If you are building in a git tree, and there are commits after the
last annotated tag.  Then the <id>-<hash> component of 'git describe'
will be used to overwrite the 'Release:' field in the META file.

The only tricky part is that to ensure the 'make dist' tarball is
built using the correct release.  A dist-hook was added to the top
level make file to rewrite the META file using the correct release.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-22 14:52:01 -07:00
Darik Horn
09fb1ec48a Fix minor typos and update marketing copy.
Correct spelling mistakes in the AUTHORS and DISCLAIMER files, and
update the README.markdown file to credit Illumos and mention that
the ZPL is finished.

The README.markdown file is also the first impression for a handful
of new users that discover ZoL through a web search because it
doubles as the splash page for the Github repository. The build blurbs
are therefore removed because these people should be encouraged to
visit the regular home page before installing the product.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1366
2013-03-21 12:51:06 -07:00
Brian Behlendorf
352b557bd6 Use requested kernel for dkms builds
The --with-linux and --with-linux-obj options must be specified
as part of the dkms build otherwise the package will be built
against the running kernel.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-21 12:51:06 -07:00
Brian Behlendorf
ae0f0ba950 Use BUILD_DEPENDS option for dkms builds
Support was added to dkms so build dependencies can be specified.
This allows us to ensure that the spl package will always be built
before the zfs package.  Those patches have not yet been merged
upstream but they are available in the zfsonlinux/dkms repository.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-21 12:51:06 -07:00
Brian Behlendorf
7865606a6a Remove zfs-dkms conflict with zfs-kmod
Because the zfs-dkms package also provides zfs-kmod for the
zfs user package yum flags this as a conflict.  To avoid the
problem remove the Conflicts tag from zfs-dkms and just rely
on the one in zfs-kmod.

  zfs-dkms-0.6.0-rc14.fc18.noarch has installed conflicts
    zfs-kmod: zfs-dkms-0.6.0-rc14.fc18.noarch

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-21 12:51:06 -07:00
Brian Behlendorf
b967600366 Refresh dracut module setup
60-zpool.rules was retired some time ago in favor of 69-vdev.rules.
Additionally, there is no guarentee a zpool.cache file exists so
only install it conditionally upon its existance.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-21 12:51:06 -07:00
Brian Behlendorf
68a2e016c8 Add missing dependencies
The spl, zfs-test, and zfs-dracut packages should be pulled in
by the core zfs package.  This allows all the required zfs packages
to be installed from a yum repository by running:

  yum install zfs

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-21 12:50:19 -07:00
Brian Behlendorf
c0c3d83ccb Add spl-dkms dependency to zfs-dkms
Adding the 'spl-dkms = VERSION' dependency to the zfs-dkms
package ensures the spl will be installed before zfs.  This
cleanly handles the initial 'yum localinstall' case.

However, this does not address the dkms rebuilds caused by
a new kernel being installed.  For that we still rely on the
clunky  --with-spl-timeout=<timeout> configure option which
allows the zfs compilation to be briefly delayed while the
spl components are built.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-19 16:17:04 -07:00
Darik Horn
ac826e1668 Create fsck.zfs and zhack man pages.
The automake templates have been updated to install them,
and the existing packaging will automatically include them.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Supplements #518
2013-03-19 13:29:13 -07:00
Brian Behlendorf
5dc6af0eec Add zio_ddt_free()+ddt_phys_decref() error handling
The assumption in zio_ddt_free() is that ddt_phys_select() must
always find a match.  However, if that fails due to a damaged
DDT or some other reason the code will NULL dereference in
ddt_phys_decref().

While this should never happen it has been observed on various
platforms.  The result is that unless your willing to patch the
ZFS code the pool is inaccessible.  Therefore, we're choosing
to more gracefully handle this case rather than leave it fatal.

http://mail.opensolaris.org/pipermail/zfs-discuss/2012-February/050972.html

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1308
2013-03-19 13:01:01 -07:00
Brian Behlendorf
30b92c1de6 Add metaslab_debug option
Enabling metaslab debugging will prevent space maps from being
automatically unloaded.  This can significantly increase the
memory footprint but being able to dynamically control this is
helpful for debugging and certain performance testing.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-18 16:47:43 -07:00
Brian Behlendorf
f3757573a6 Refresh RPM packaging
Refresh the existing RPM packaging to conform to the 'Fedora
Packaging Guidelines'.  This includes adopting the kmods2
packaging standard which is used fod kmods distributed by
rpmfusion for Fedora/RHEL.

  http://fedoraproject.org/wiki/Packaging:Guidelines
  http://rpmfusion.org/Packaging/KernelModules/Kmods2

While the spec files have been entirely rewritten from a
user perspective the only major changes are:

* The Fedora packages now have a build dependency on the
  rpmfusion repositories.  The generic kmod packages also
  have a new dependency on kmodtool-1.22 but it is bundled
  with the source rpm so no additional packages are needed.

* The kernel binary module packages have been renamed from
  zfs-modules-* to kmod-zfs-* as specificed by kmods2.

* The is now a common kmod-zfs-devel-* package in addition
  to the per-kernel devel packages.  The common package
  contains the development headers while the per-kernel
  package contains kernel specific build products.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1341
2013-03-18 15:33:17 -07:00
Brian Behlendorf
9b2af9a097 Configure --with-spl{-obj} auto-detect cleanup
Because the install location for the spl/zfs-devel headers was
changed we need to refresh the auto-detect code.  Note that
for packaging which already explicitly calls --with-spl{-obj}
nothing has changed.

The updated code is now structured like that in ZFS_AC_KERNEL
and should be cleaner and easier to maintain.  In addition,
it's stricter about detecting a valid source and object
directory.  It requires:

* The source directory contains the file 'spl.release'
* The object directory contains the file 'spl_config.h'
* The following paths will be checked.  Notice the /var/lib/
  and /usr/src paths require that the spl and zfs version be
  matched.  This is done to prevent accidentally mixing releases.

        dnl # 1) /var/lib/dkms/spl/<version>/build
        dnl # 2) /usr/src/spl-<version>/<kernel-version>
        dnl # 3) /usr/src/spl-<version>
        dnl # 4) ../spl
        dnl # 5) /usr/src/kernels/<kernel-version>

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-13 13:42:16 -07:00
Brian Behlendorf
775f2d34a3 Change zfs-kmod-devel install path
Install the common zfs kernel development headers under
/usr/src/zfs-<version>/ rather than in a kernel specific
directory.  The kernel specific build products such as
zfs_config.h and Modules.symvers are left installed under
/usr/src/zfs-<version>/<kernel>.

This was done to be consistent with where dkms expects
kernel module source to be packaged.  It also allows for
a common zfs-kmod-devel package which includes the headers,
and per-kernel zfs-kmod-devel-<kernel> packages.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-13 13:42:16 -07:00
Brian Behlendorf
d69b2dee71 Remove COPYING
There's no reason to keep this file around it's redundant with
the COPYRIGHT and OPENSOLARIS.LICENSE files and causes lintian
to emit an extra-license-file warning.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-13 13:42:16 -07:00
Darik Horn
cf2129e6dc Create mount.zfs, zinject, and zpios man pages.
And update the automake templates to install them.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #518
2013-03-13 13:41:22 -07:00
Michael Gebetsroither
5cd0add214 Import ztest.1 man page.
Create a nroff man page for ZoL from:

  http://grml.org/online-docs/ztest.1.html

Which itself was derived from:

  http://opensolaris.org/os/community/zfs/ztest/

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #518
2013-03-13 13:40:04 -07:00
Richard Yao
1c24b699b0 Linux 3.9 compat: Undefine GCC_VERSION
The mainline kernel started defining GCC_VERSION with commit
torvalds/linux@3f3f8d2f48.
Unfortunately, LZ4 also defines this macro, but the two
defintions are incompatible. We undefine GCC_VERSION in lz4.c
to handle this.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1339
2013-03-06 15:48:48 -08:00
Brian Behlendorf
7c72f8e391 Merge branch 'build-system' 2013-03-06 15:47:38 -08:00
Brian Behlendorf
2016ff96d1 Fix zdb.8 macro warning
Detected by rpmlint the 'rpool/export/home' section was being
interpretted by troff as an undefined macro.  This resulted
in the 'rpool/export/home' output being omitted from 'man zdb'.

This was caused by starting the line with a ' character.  By
moving the 'in' down to the next line we're able to fix it.

  zfs.x86_64: W: manual-page-warning /usr/share/man/man8/zdb.8.gz
  450: warning: macro `rpool/export/home'' not defined

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:41 -08:00
Ned Bass
92db59ca3b Refresh links to web site
A few files still refer to @behlendorf's private fork on
github.  Use the primary web site URL instead.  Two typos
are also corrected.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:41 -08:00
Brian Behlendorf
e07b579b1b Retire ZFS.RELEASE file
The ZFS.RELEASE file was originally added to document which
version of OpenSolaris the ZoL code was based on.  However,
that's no longer particularly important or useful.  We'll
likely never see a new onnv_* drop from Solaris, and even
if we do the ZoL changes are now extensive enough they
could not be easily applied.  We now treat Illumos as the
official upstream and cherry pick the patches we need.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:41 -08:00
Brian Behlendorf
0da31cd6ca Remove ARCH packaging
The kernel modules are now available in the Arch User Repository
(AUR) via zfs.  Since their packaging is maintained and superior
to ours it is being removed from the tree.

  https://wiki.archlinux.org/index.php/ZFS

Now that various distributions are picking up the packages we
should eventually be able to remove most of this infrastructure.
Packaging belongs with the distributions not upstream.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:41 -08:00
Brian Behlendorf
ffb21118ad Add --with-dracutdir configure option
The standard dracut directory has moved from /usr/share/dracut to
/usr/lib/dracut.  To ensure the dracut modules get installed in
the correct location provide a --with-dracutdir configure option
to set the path.

The default install location has been updated to /usr/lib/dracut
which is used by more current versions of Fedora.  However, this
default is overriden by the RPM packaging for consistency.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:41 -08:00
Brian Behlendorf
d09f98a9a6 Add KMODDIR to install target
Provide a mechanism to control the directory name the modules
are installed in.  The kernel privdes INSTALL_MOD_DIR for
this but it was hardcoded to be 'addon/zfs'.

Add a KMODDIR variable which can be passed to 'make install'
to override the default directory name.  While we're here
change the default from 'addon/zfs' to 'extra' which is the
kernel.org default.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:40 -08:00
Brian Behlendorf
fd2b4aa71a Fix zfs_config.h install permissions
The default permissions used by install are 755.  Since this
file isn't executable 644 is more appropriate.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:40 -08:00
Brian Behlendorf
48c028f5a5 Replace libexecdir with datadir
According to the FHS.  Testing scripts and examples which are all
architecture independent should be installed in a subdirectory
under /usr/share.

  http://www.pathname.com/fhs/2.2/fhs-4.11.html

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-06 15:46:40 -08:00
Eric Dillmann
0b4d1b5853 Add snapdev=[hidden|visible] dataset property
The new snapdev dataset property may be set to control the
visibility of zvol snapshot devices.  By default this value
is set to 'hidden' which will prevent zvol snapshots from
appearing under /dev/zvol/ and /dev/<dataset>/.  When set to
'visible' all zvol snapshots for the dataset will be visible.

This functionality was largely added because when automatic
snapshoting is enabled large numbers of read-only zvol snapshots
will be created.  When creating these devices the kernel will
attempt to read their partition tables, and blkid will attempt
to identify any filesystems on those partitions.  This leads
to a variety of issues:

1) The zvol partition tables will be read in the context of
   the `modprobe zfs` for automatically imported pools.  This
   is undesirable and should be done asynchronously, but for
   now reducing the number of visible devices helps.

2) Udev expects to be able to complete its work for a new
   block devices fairly quickly.  When many zvol devices are
   added at the same time this is no longer be true.  It can
   lead to udev timeouts and missing /dev/zvol links.

3) Simply having lots of devices in /dev/ can be aukward from
   a management standpoint.  Hidding the devices your unlikely
   to ever use helps with this.  Any snapshot device which is
   needed can be made visible by changing the snapdev property.

NOTE: This patch changes the default behavior for zvols which
      was effectively 'snapdev=visible'.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1235
Closes #945
Issue #956
Issue #756
2013-03-05 12:37:54 -08:00
George Wilson
a4430fce69 Merge zvol.c changes from PSARC 2010/306 Read-only ZFS pools
The changes to zvol.c were never merged from the last onnv_147
bulk update.  This was because zvol.c was largely rewritten
for Linux making it fairly easy to miss these sorts of changes.

This causes a regression when importing a zpool with zvols
read-only.  This does not impact pool which only contain
filesystem datasets.

References:
  illumos/illumos-gate@f9af39b

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1332
Closes #1333
2013-03-04 09:56:13 -08:00
Richard Yao
b01615d5ac Constify structures containing function pointers
The PaX team modified the kernel's modpost to report writeable function
pointers as section mismatches because they are potential exploit
targets. We could ignore the warnings, but their presence can obscure
actual issues. Proper const correctness can also catch programming
mistakes.

Building the kernel modules against a PaX/GrSecurity patched Linux 3.4.2
kernel reports 133 section mismatches prior to this patch. This patch
eliminates 130 of them. The quantity of writeable function pointers
eliminated by constifying each structure is as follows:

vdev_opts_t             52
zil_replay_func_t       24
zio_compress_info_t     24
zio_checksum_info_t     9
space_map_ops_t         7
arc_byteswap_func_t     5

The remaining 3 writeable function pointers cannot be addressed by this
patch. 2 of them are in zpl_fs_type. The kernel's sget function requires
that this be non-const. The final writeable function pointer is created
by SPL_SHRINKER_DECLARE. The kernel's set_shrinker() and
remove_shrinker() functions also require that this be non-const.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1300
2013-03-04 08:49:32 -08:00
Richard Yao
c38367c73f Eliminate runtime function pointer mods in autotools checks
PaX/GrSecurity patched kernels implement a dialect of C that relies on a
GCC plugin for enforcement. A basic idea in this dialect is that
function pointers in structures should not change during runtime.
This causes code that modifies function pointers at runtime to fail to
compile in many instances. The autotools checks rely on whether or
not small test cases compile against a given kernel. Some
autotools checks assume some default case if other cases fail. When one
of these autotools checks tests a PaX/GrSecurity patched kernel by
modifying a function pointer at runtime, the default case will be used.

Early detection of such situations is possible by relying on compiler
warnings, which are compiler errors when --enable-debug is used.
Unfortunately, very few people build ZFS with --enable-debug. The more
common situation is that these issues manifest themselves as runtime
failures in the form of NULL pointer exceptions.

Previous patches that addressed such issues with PaX/GrSecurity
compatibility largely relied on rewriting autotools checks to avoid
runtime function pointer modification or the addition of PaX/GrSecurity
specific checks. This patch takes the previous work to its logical
conclusion by eliminating the use of runtime function pointer
modification. This permits the removal of PaX-specific autotools checks
in favor of ones that work across all supported kernels.

This should resolve issues that were reported to occur with
PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux.

https://bugs.gentoo.org/show_bug.cgi?id=457176

We should be able to prevent future regressions in PaX/GrSecurity
compatibility by ensuring that all changes to ZFSOnLinux avoid runtime
function pointer modification. At the same time, this does not solve the
issue of silent failures triggering default cases in the autotools
check, which is what permitted these regressions to become runtime
failures in the first place. This will need to be addressed in a future
patch.

Reported-by: Marcin Mirosław <bug@mejor.pl>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1300
2013-03-04 08:49:17 -08:00