Newer versions of gcc are getting smart enough to detect the sloppy
syntax used for the autoconf tests. It is now generating warnings
for unused/undeclared variables. Newer version of gcc even have
the -Wunused-but-set-variable option set by default. This isn't a
problem except when -Werror is set and they get promoted to an error.
In this case the autoconf test will return an incorrect result which
will result in a build failure latter on.
To handle this I'm tightening up many of the autoconf tests to
explicitly mark variables as unused to suppress the gcc warning.
Remember, all of the autoconf code can never actually be run we
just want to get a clean build error to detect which APIs are
available. Never using a variable is absolutely fine for this.
Closes#176
Added insert_inode_locked() helper function, prior to this most callers
used insert_inode_hash(). The older method doesn't check for collisions
in the inode_hashtable but it still acceptible for use. Fallback to
using insert_inode_hash() when insert_inode_locked() is unavailable.
To simplify the process of using zfs as your root filesystem a
zfs-drucat sub-package has been added. This sub-package adds a zfs
dracut module which allows your initramfs to be rebuilt with zfs
support. The process for doing this is still complicated but there
is clearly interest from the community about getting this working
well and documented. This should help lay some of the groundwork.
Longer term these changes should be pushed in the upstream dracut
package. Once that occurs this subpackage will no longer be
required for new systems, however we may want to conditionally
build this package in the future for systems running older
dracut versions.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
To support automatically mounting your zfs on filesystem on boot
a basic init script is needed. Unfortunately, every distribution
has their own idea of the _right_ way to do things. Rather than
write one very complicated portable init script, which would be
invariably replaced by the distributions own anyway. I have
instead added support to provide multiple distribution specific
init scripts.
The correct init script for your distribution will be selected
by ZFS_AC_DEFAULT_PACKAGE which will set DEFAULT_INIT_SCRIPT.
During 'make install' the correct script for your system will
be installed from zfs/etc/init.d/zfs.DEFAULT_INIT_SCRIPT to the
usual /etc/init.d/zfs location.
Currently, there is zfs.fedora and a more generic zfs.lsb init
script. Hopefully, the distribution maintainers who know best
how they want their init scripts to function will feedback their
approved versions to be included in the project.
This change does not consider upstart jobs but I'm not at all
opposed to add that sort of thing.
Detect early on in configure if the Modules.symvers file is missing.
Without this file there will be build failures later and it's best
to catch this early and provide a useful error. In this case the
most likely problem is the kernel-devel packages are not installed.
It may also be possible that they are using an unbuilt custom kernel
in which case they must build the kernel first.
Closes#127
Until support is added for preemptible kernels detect this at
configure time and make it fatal. Otherwise, it is possible to
have a successful build and kernel modules with flakey behavior.
The open_bdev_exclusive() function has been replaced (again) by the
more generic blkdev_get_by_path() function. Additionally, the
counterpart function close_bdev_exclusive() has been replaced by
blkdev_put(). Because these functions are more generic versions
of the functions they replaced the compatibility macro must add
the FMODE_EXCL mask to ensure they are exclusive.
Closes#114
The new prefered inteface for evicting an inode from the inode cache
is the ->evict_inode() callback. It replaces both the ->delete_inode()
and ->clear_inode() callbacks which were previously used for this.
The xattr handler prototypes were sanitized with the idea being that
the same handlers could be used for multiple methods. The result of
this was the inode type was changes to a dentry, and both the get()
and set() hooks had a handler_flags argument added. The list()
callback was similiarly effected but no autoconf check was added
because we do not use the list() callback.
The fsync() callback in the file_operations structure used to take
3 arguments. The callback now only takes 2 arguments because the
dentry argument was determined to be unused by all consumers. To
handle this a compatibility prototype was added to ensure the right
prototype is used. Our implementation never used the dentry argument
either so it's just a matter of using the right prototype.
The const keyword was added to the 'struct xattr_handler' in the
generic Linux super_block structure. To handle this we define an
appropriate xattr_handler_t typedef which can be used. This was
the preferred solution because it keeps the code clean and readable.
Preferentially use the /lib/modules/$(uname -r)/source and
/lib/modules/$(uname -r)/build links. Only if neither of these
links exist fallback to alternate methods for deducing which
kernel to build with. This resolves the need to manually
specify --with-linux= and --with-linux-obj= on Debian systems.
ZFS even under Solaris does not strictly require libshare to be
available. The current implementation attempts to dlopen() the
library to access the needed symbols. If this fails libshare
support is simply disabled.
This means that on Linux we only need the most minimal libshare
implementation. In fact just enough to prevent the build from
failing. Longer term we can decide if we want to implement a
libshare library like Solaris. At best this would be an abstraction
layer between ZFS and NFS/SMB. Alternately, we can drop libshare
entirely and directly integrate ZFS with Linux's NFS/SMB.
Finally the bare bones user-libshare.m4 test was dropped. If we
do decide to implement libshare at some point it will surely be
as part of this package so the check is not needed.
If libselinux is detected on your system at configure time link
against it. This allows us to use a library call to detect if
selinux is enabled and if it is to pass the mount option:
"context=\"system_u:object_r:file_t:s0"
For now this is required because none of the existing selinux
policies are aware of the zfs filesystem type. Because of this
they do not properly enable xattr based labeling even though
zfs supports all of the required hooks.
Until distro's add zfs as a known xattr friendly fs type we
must use mntpoint labeling. Alternately, end users could modify
their existing selinux policy with a little guidance.
Refresh the autogen.sh products based on the versions which are
installed by default in the GA RHEL6.0 release.
autoconf (GNU Autoconf) 2.63
automake (GNU automake) 1.11.1
ltmain.sh (GNU libtool) 2.2.6b
The name of the flag used to mark a bio as synchronous has changed
again in the 2.6.36 kernel due to the unification of the BIO_RW_*
and REQ_* flags. The new flag is called REQ_SYNC. To simplify
checking this flag I have introduced the vdev_disk_dio_is_sync()
helper function. Based on the results of several new autoconf
tests it uses the correct mask to check for a synchronous bio.
Preferred interface for flagging a synchronous bio:
2.6.12-2.6.29: BIO_RW_SYNC
2.6.30-2.6.35: BIO_RW_SYNCIO
2.6.36-2.6.xx: REQ_SYNC
As of linux-2.6.36 the BIO_RW_FAILFAST and REQ_FAILFAST flags
have been unified under the REQ_* names. These flags always had
to be kept in-sync so this is a nice step forward, unfortunately
it means we need to be careful to only use the new unified flags
when the BIO_RW_* flags are not defined. Additional autoconf
checks were added for this and if it is ever unclear which method
to use no flags are set. This is safe but may result in longer
delays before a disk is failed.
Perferred interface for setting FAILFAST on a bio:
2.6.12-2.6.27: BIO_RW_FAILFAST
2.6.28-2.6.35: BIO_RW_FAILFAST_{DEV|TRANSPORT|DRIVER}
2.6.36-2.6.xx: REQ_FAILFAST_{DEV|TRANSPORT|DRIVER}
ZFS works best when it is notified as soon as possible when a device
failure occurs. This allows it to immediately start any recovery
actions which may be needed. In theory Linux supports a flag which
can be set on bio's called FAILFAST which provides this quick
notification by disabling the retry logic in the lower scsi layers.
That's the theory at least. In practice is turns out that while the
flag exists you oddly have to set it with the BIO_RW_AHEAD flag.
And even when it's set it you may get retries in the low level
drivers decides that's the right behavior, or if you don't get the
right error codes reported to the scsi midlayer.
Unfortunately, without additional kernels patchs there's not much
which can be done to improve this. Basically, this just means that
it may take 2-3 minutes before a ZFS is notified properly that a
device has failed. This can be improved and I suspect I'll be
submitting patches upstream to handle this.
One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory. The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.
For example, this project is designed to work on various different
Linux distributions each of which work slightly differently. This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.
Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution. When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.
wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z
------------------------- run concurrently ----------------------
<ubuntu system> <fedora system> <debian system> <rhel6 system>
mkdir ubuntu mkdir fedora mkdir debian mkdir rhel6
cd ubuntu cd fedora cd debian cd rhel6
../configure ../configure ../configure ../configure
make make make make
make check make check make check make check
This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory. This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.
The spl_config.h file is checked to determine the spl version.
However, the zfs code was looking for it in the source directory
and not the build directory.
Add the initial products from autogen.sh. These products will
be updated incrementally after this point as development occurs.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Add autoconf style build infrastructure to the ZFS tree. This
includes autogen.sh, configure.ac, m4 macros, some scripts/*,
and makefiles for all the core ZFS components.
of the kernel specific build info in to config/kernel,
likewise and user specific build flags should go in
config/user. This seems like a reasonable way to go.
