It appears that in earlier kernels the maximum name length of a
kobject was KOBJ_NAME_LEN (20) bytes. This was later extended to
dynamically allocate enough memory if it was over KOBJ_NAME_LEN,
and finally it was always made dynamic. Unfortunately, util this
last step happened it doesn't look like it always safe to use
names larger than KOBJ_NAME_LEN. For example, under the RHEL5
2.6.18 kernel if the kobject name length exceeds KOBJ_NAME_LEN
a NULL dereference is tripped.
To avoid this issue the build system has been update to check
to see if KOBJ_NAME_LEN is defined. If it is we have to assume
the maximum kobject name length is only 20 bytes. This 20 byte
name must minimally include the following components.
<zpool>/<dataset>[@snapshot[partition]]
While in theory I like the idea of compiler warnings always being
fatal. In practice this causes problems when small harmless errors
cause build failures for end users. To handle this I've updated
the build system such that -Werror is only used when --enable-debug
is passed to configure. This is how I always build when developing
so I'll catch all build warnings and end users will not get stuck
by minor issues.
As of autoconf-2.65 the AC_LANG_SOURCE source macro no longer
includes the confdef.h results when expanded. To handle this
simply explicitly include confdef.h in conftest.c. This will
cause two copies to of confdef.h to be added to the test for
earlier autoconf versions but this is not harmful.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
It seems the upstream community moved the definition of UTS_RELEASE
yet again as of linux-2.6.33. Update the build system to check in
all three possible locations where your kernel version may be defined.
$kernelbuild/include/linux/version.h
$kernelbuild/include/linux/utsrelease.h
$kernelbuild/include/generated/utsrelease.h
We need dependent packages to be able to include zfs_config.h to
build properly. This was partially solved previously be using
AH_BOTTOM to #undef common #defines (PACKAGE, VERSION, etc) which
autoconf always adds and cannot be easily removed. This solution
works as long as the zfs_config.h is included before your projects
config.h. That turns out to be easier said than done. In particular,
this is a problem when your package includes its config.h using the
-include gcc option which ensures the first thing included is your
config.h.
To handle all cases cleanly I have removed the AH_BOTTOM hack and
replaced it with an AC_CONFIG_HEADERS command. This command runs
immediately after zfs_config.h is written and with a little awk-foo
it strips the offending #defines from the file. This eliminates
the problem entirely and makes header safe for inclusion.
Previously the ZFS configure was dependent on a correct Module{s}.symvers
file which is generated as one of the last steps of the full SPL build.
This meant you could not do a recursive configure because this will
configure all sub-packages before building any of them.
To resolve this issue the ZFS code has been updated to make a very
educated guess as to this file name at configure time. This means
SPL_SYMBOLS may still be used in various places in the build system
such as modules/Makefile.in. But we do give up the ability to
seemlessly detect symbols exported by the SPL at ZFS configure time.
At the moment this is not as issue, hopefully it will stay that way.
/lib/modules/$(uname -r)/source. This will likely fail when building
under a mock (http://fedoraproject.org/wiki/Projects/Mock) chroot
environment since `uname -r` will report the running kernel which
likely is not the kernel in your chroot. To cleanly handle this
we fallback to using the first kernel in your chroot.
The kernel-devel package which contains all the kernel headers and
a few build products such as Module.symver{s} is all the is required.
Full source is not needed.
Twice now I've been bitten by building agaist a kernel which is
configured such that it is incompatible with the CDDL license. These
build failures don't occur until the linking phase at which point they
simply callout the offending symbol. No location information can be
provided at this point so it often can be confusing what the problem is
particularly when building against a new kernel for the first time.
To help address this I've added a configure check which can be extended
over time to detect known kernel config options which if set will break
the ZFS build. Currently I have just added CONFIG_DEBUG_LOCK_ALLOC which
makes mutex's GPL-only and is on by default in the RHEL6 alpha builds.
I know for a fact there are other similiar options which can be added
as they are encountered.
2.6.22 API change
Unused destroy_dirty_buffers arg removed from prototype.
2.6.24 API change
Empty write barriers are now supported and we should use them.
2.6.24 API change
Size argument dropped from bio_endio and bi_end_io, because the
bi_end_io is only called once now when the request is complete.
There is no longer any need for a size argument. This also means
that partial IO's are no longer possibe and the end_io callback
should not check bi->bi_size. Finally, the return type was updated
to void.
2.6.28 API change
open/close_bdev_excl() renamed to open/close_bdev_exclusive().
2.6.29 API change
BIO_RW_SYNC renamed to BIO_RW_SYNCIO.
Modern kernel build systems at least post 2.6.16 will set this properly
so we should not. In fact post 2.6.28 the include headers have moved
under arch so the guess we make here is completely wrong. Letting
the kernel build system set this ensure it will be correct. Also
drop the ulimit from the Makefile which, not surprisingly, turns out
to be very non-portable. If your expecting failures set the ulimit
in your shell before kicking off the test suite.
when used to generate source rpms. These should not be fatal
because we actually don't need them until we build the source
rpm. When doing mock build this is important because these
dependent rpms will only be installed if they are specificed
in the source rpms spec file.
These changes bring the zfs-0.4.4 tree in to compliance with
the spl-0.4.4 packaging changes. The bottom line is 2 source
rpms and 4 binary rpms will now be generated when creating
packages there will be:
zfs-<version>.src.rpm
- Fully rebuildable source rpm for libzfs and utils.
zfs-modules-<version>.src.rpm
- Fully rebuildable source rpm for kernel modules.
zfs-<version>.<arch>.rpm
- Binary rpm for libzfs and utils. The utils in this package are
compatible with all zfs-module rpms of the same version.
zfs-devel-<version>.<arch>.rpm
- Binary rpm containing headers for building against libzfs libraries.
zfs-modules-<verion>-<kernel>.arch.rpm
- Binary rpm containing the kernel modules for a specific kernel build.
The package name contains the kernel version and you should have one
of these packages installed to match every kernel on your system.
zfs-modules-devel-<verion>-<kernel>.arch.rpm
- Binary rpm containing development header and module symbols needed
for building additional kernel modules which are dependent on the
zfs module stack.
Expect minor interations on these changes as I validate they work
properly on CHAOS, RHEL, Fedora, and SLES style distros.
All these errors are now either addressed in a gcc-* topic branch, or
in whatever branch the original warning was introduced by (i.e. I fixed
the bug which just went unnoticed until now due to the compiler flags)
Brian Behlendorf
Lars Johannsen
Brian J. Murrell