Autoconf will fail to detect the ZoL libnvpair on systems that do not
implicitly link library runtime dependencies, which is anything that
has the GCC 4.5 DCO update.
Build libuutil before libnvpair, and put it on the the LDADD line of
the libnvpair automake template.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #560
The second argument of sops->show_options() was changed from a
'struct vfsmount *' to a 'struct dentry *'. Add an autoconf check
to detect the API change and then conditionally define the expected
interface. In either case we are only interested in the zfs_sb_t.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#549
Historically the internal zfs debug infrastructure has been
scattered throughout the code. Since we expect to start making
more use of this code this patch performs some cleanup.
* Consolidate the zfs debug infrastructure in the zfs_debug.[ch]
files. This includes moving the zfs_flags and zfs_recover
variables, plus moving the zfs_panic_recover() function.
* Remove the existing unused functionality in zfs_debug.c and
replace it with code which correctly utilized the spl logging
infrastructure.
* Remove the __dprintf() function from zfs_ioctl.c. This is
dead code, the dprintf() functionality in the kernel relies
on the spl log support.
* Remove dprintf() from hdr_recl(). This wasn't particularly
useful and was missing the required format specifier anyway.
* Subsequent patches should unify the dprintf() and zfs_dbgmsg()
functions.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Since the zpios and potentially other ZFS tests use the
DMU_OST_OTHER type to label their datasets, the zpool and
zfs commands should gracefully handle this type when it is
encountered. This patch modifies the commands' behavior
to ignore any datasets with a dds_type of DMU_OST_OTHER.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#536
Commit zfsonlinux/zfs@57a4eddc4d
allows the bootfs property to be set on any pool, but does not
accommodate subsequent vdev changes. For example:
# zpool replace rpool /dev/sda /dev/sdb
operation not supported on this type of pool
property 'bootfs' is not supported on EFI labeled devices
For non-Solaris builds, disable the check that emits this error.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
These libraries, which are an artifact of the ZoL development
process, conflict with packages that are already in distribution:
* libspl: SPL Programming Language
* libavl: AVL for Linux
* libefi: GRUB
And these libraries are potential conflicts:
* libshare: the Linux Mount Manager
* libunicode: Perl and Python
Recompose these five ZoL components into the four libraries that are
conventionally provided by Solaris and FreeBSD systems:
+ libnvpair
+ libuutil
+ libzpool
+ libzfs
This change resolves the name conflict, makes ZoL more compatible
with existing software that uses autotools to detect ZFS, and allows
pkg-zfs to better reflect the official Debian kFreeBSD packaging.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #430
Linux supports mounting over non-empty directories by default.
In Solaris this is not the case and -O option is required for
zfs mount to mount a zfs filesystem over a non-empty directory.
For compatibility, I've added support for -O option to mount
zfs filesystems over non-empty directories if the user wants
to, just like in Solaris.
I've defined MS_OVERLAY to record it in the flags variable if
the -O option is supplied. The flags variable passes through
a few functions and its checked before performing the empty
directory check in zfs_mount function. If -O is given, the
check is not performed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#473
The Linux 3.1 kernel has introduced the concept of per-filesystem
shrinkers which are directly assoicated with a super block. Prior
to this change there was one shared global shrinker.
The zfs code relied on being able to call the global shrinker when
the arc_meta_limit was exceeded. This would cause the VFS to drop
references on a fraction of the dentries in the dcache. The ARC
could then safely reclaim the memory used by these entries and
honor the arc_meta_limit. Unfortunately, when per-filesystem
shrinkers were added the old interfaces were made unavailable.
This change adds support to use the new per-filesystem shrinker
interface so we can continue to honor the arc_meta_limit. The
major benefit of the new interface is that we can now target
only the zfs filesystem for dentry and inode pruning. Thus we
can minimize any impact on the caching of other filesystems.
In the context of making this change several other important
issues related to managing the ARC were addressed, they include:
* The dnlc_reduce_cache() function which was called by the ARC
to drop dentries for the Posix layer was replaced with a generic
zfs_prune_t callback. The ZPL layer now registers a callback to
drop these dentries removing a layering violation which dates
back to the Solaris code. This callback can also be used by
other ARC consumers such as Lustre.
arc_add_prune_callback()
arc_remove_prune_callback()
* The arc_reduce_dnlc_percent module option has been changed to
arc_meta_prune for clarity. The dnlc functions are specific to
Solaris's VFS and have already been largely eliminated already.
The replacement tunable now represents the number of bytes the
prune callback will request when invoked.
* Less aggressively invoke the prune callback. We used to call
this whenever we exceeded the arc_meta_limit however that's not
strictly correct since it results in over zeleous reclaim of
dentries and inodes. It is now only called once the arc_meta_limit
is exceeded and every effort has been made to evict other data from
the ARC cache.
* More promptly manage exceeding the arc_meta_limit. When reading
meta data in to the cache if a buffer was unable to be recycled
notify the arc_reclaim thread to invoke the required prune.
* Added arcstat_prune kstat which is incremented when the ARC
is forced to request that a consumer prune its cache. Remember
this will only occur when the ARC has no other choice. If it
can evict buffers safely without invoking the prune callback
it will.
* This change is also expected to resolve the unexpect collapses
of the ARC cache. This would occur because when exceeded just the
arc_meta_limit reclaim presure would be excerted on the arc_c
value via arc_shrink(). This effectively shrunk the entire cache
when really we just needed to reclaim meta data.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#466Closes#292
Directly changing inode->i_nlink is deprecated in Linux 3.2 by commit
SHA: bfe8684869601dacfcb2cd69ef8cfd9045f62170
Use the new set_nlink() kernel function instead.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #462
Added the necessary build infrastructure for building packages
compatible with the Arch Linux distribution. As such, one can now run:
$ ./configure
$ make pkg # Alternatively, one can run 'make arch' as well
on the Arch Linux machine to create two binary packages compatible with
the pacman package manager, one for the zfs userland utilities and
another for the zfs kernel modules. The new packages can then be
installed by running:
# pacman -U $package.pkg.tar.xz
In addition, source-only packages suitable for an Arch Linux chroot
environment or remote builder can also be build using the 'sarch' make
rule.
NOTE: Since the source dist tarball is created on the fly from the head
of the build tree, it's MD5 hash signature will be continually influx.
As a result, the md5sum variable was intentionally omitted from the
PKGBUILD files, and the '--skipinteg' makepkg option is used. This may
or may not have any serious security implications, as the source tarball
is not being downloaded from an outside source.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#491
It has been observed that some of the hottest locks are those
of the zio taskqs. Contention on these locks can limit the
rate at which zios are dispatched which limits performance.
This upstream change from Illumos uses new interface to the
taskqs which allow them to utilize a prealloc'ed taskq_ent_t.
This removes the need to perform an allocation at dispatch
time while holding the contended lock. This has the effect
of improving system performance.
Reviewed by: Albert Lee <trisk@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Alexey Zaytsev <alexey.zaytsev@nexenta.com>
Reviewed by: Jason Brian King <jason.brian.king@gmail.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References to Illumos issue:
https://www.illumos.org/issues/734
Ported-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#482
Some of the functions' purpose wasn't immediately obvious without
additional explanations. This commit adds these missing comments.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
While setting/getting userquota and groupquota properties, the input
was not treated as a possible username or groupname if it had a
leading digit. While useradd in linux recommends the regexp
[a-z_][a-z0-9_-]*[$]? , it is not enforced. This causes problem for
usernames with leading digits in them. We need to be able to support
getting and setting properties for this unconventional but possible
input category
I've updated the code to validate the username or groupname directly
via the API. Also, note that I moved this validation to the beginning
before the check for SID names with @. This also supports usernames
with @ character in them which are valid. Only when input with @ is
not a valid username, it is interpreted as a potential SID name.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#428
While we initially allowed you to set your ashift as large as 17
(SPA_MAXBLOCKSIZE) that is actually unsafe. What wasn't considered
at the time is that each uberblock written to the vdev label ring
buffer will be of this size. Now the buffer is statically sized
to 128k and we need to be able to fit several uberblocks in it.
With a large ashift that becomes a problem.
Therefore I'm reducing the maximum configurable ashift value to 12.
This is large enough for the 4k sector drives and small enough that
we can still keep the most recent 32 uberblock in the vdev label
ring buffer.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#425
Update the code to use the bdi_setup_and_register() helper to
simplify the bdi integration code. The updated code now just
registers the bdi during mount and destroys it during unmount.
The only complication is that for 2.6.32 - 2.6.33 kernels the
helper wasn't available so in these cases the zfs code must
provide it. Luckily the bdi_setup_and_register() function
is trivial.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#367
GPT's created by libefi set the HeaderSize attribute in the GPT
header to 512 -- size of the GPT header INCLUDING the 420 padding
bytes at the end. Most other tools set the size to 92 -- size of
the actual header itself excluding the padding. Most tools check
the recorded HeaderSize when verifying CRC, but gptfdisk hardcodes
92 and thus reports CRC verification problems for full-disk vdevs
created IE with `zpool create pool sdc`.
This commit changes libefi's behavior for GPT creation and also
fixes several edge cases where libefi's behavior was similar
(though in an incompatible manner) to gptfdisk. Libefi assumed
HeaderSize was always 512 even if the GPT recorded a different
value. Sanity checks of the GPT headersize read from disk were
added before applying checksum calculation -- this will prevent
segfault in cases of bogus on-disk values.
Zpools created with the resuling libefi are verified as correct
both by parted and gptfdisk. Also pool have been tested to
import correctly on ZFS on Linux as well as Solaris Express 11
livecd.
Signed-off-by: Zachary Bedell <zac@thebedells.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#344
For a long time now the kernel has been moving away from using the
pdflush daemon to write 'old' dirty pages to disk. The primary reason
for this is because the pdflush daemon is single threaded and can be
a limiting factor for performance. Since pdflush sequentially walks
the dirty inode list for each super block any delay in processing can
slow down dirty page writeback for all filesystems.
The replacement for pdflush is called bdi (backing device info). The
bdi system involves creating a per-filesystem control structure each
with its own private sets of queues to manage writeback. The advantage
is greater parallelism which improves performance and prevents a single
filesystem from slowing writeback to the others.
For a long time both systems co-existed in the kernel so it wasn't
strictly required to implement the bdi scheme. However, as of
Linux 2.6.36 kernels the pdflush functionality has been retired.
Since ZFS already bypasses the page cache for most I/O this is only
an issue for mmap(2) writes which must go through the page cache.
Even then adding this missing support for newer kernels was overlooked
because there are other mechanisms which can trigger writeback.
However, there is one critical case where not implementing the bdi
functionality can cause problems. If an application handles a page
fault it can enter the balance_dirty_pages() callpath. This will
result in the application hanging until the number of dirty pages in
the system drops below the dirty ratio.
Without a registered backing_device_info for the filesystem the
dirty pages will not get written out. Thus the application will hang.
As mentioned above this was less of an issue with older kernels because
pdflush would eventually write out the dirty pages.
This change adds a backing_device_info structure to the zfs_sb_t
which is already allocated per-super block. It is then registered
when the filesystem mounted and unregistered on unmount. It will
not be registered for mounted snapshots which are read-only. This
change will result in flush-<pool> thread being dynamically created
and destroyed per-mounted filesystem for writeback.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#174
This should simplify the code a bit by re-using existing code
to fork and exec a process.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #190
Simply closing the stdout and/or stderr file descriptors for
the child process can have bad side effects if for example
the child writes to stdout/stderr after open()ing a file.
The open() call might have returned the same file descriptor
one would usually expect for stdout/stderr (1 and 2), thereby
causing mis-directed writes.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #190
At the moment we call exportfs -v every time we check whether an
NFS share is active. This happens every time you run a zfs or
zpool command, making them extremely slow when you have a lot of
exports. The time taken is approx O(n2) of the number of shares.
This commit stores the output from exportfs -v in a temporary file
and use this to speed up subsequent accesses.
This mechanism is still too slow - if you have tens of thousands
of NFS shares it will still be painful running ANY zfs/zpool
command.
Signed-off-by: Gunnar Beutner <gunnar@beutner.name>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#341
Add a "REFRATIO" property, which is the compression ratio based on
data referenced. For snapshots, this is the same as COMPRESSRATIO,
but for filesystems/volumes, the COMPRESSRATIO is based on the
data "USED" (ie, includes blocks in children, but not blocks
shared with the origin).
This is needed to figure out how much space a filesystem would
use if it were not compressed (ignoring snapshots).
Reviewed by: George Wilson <George.Wilson@delphix.com>
Reviewed by: Adam Leventhal <Adam.Leventhal@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Mark Musante <Mark.Musante@oracle.com>
Reviewed by: Garrett D'Amore <garrett@nexenta.com>
Approved by: Garrett D'Amore <garrett@nexenta.com>
References to Illumos issue and patch:
- https://www.illumos.org/issues/1092
- https://github.com/illumos/illumos-gate/commit/187d6ac08a
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #340
Unlike most other Linux distributions archlinux installs its
init scripts in /etc/rc.d insead of /etc/init.d. This commit
provides an archlinux rc.d script for zfs and extends the
build infrastructure to ensure it get's installed in the
correct place.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#322
The zfs libraries were never properly versioned. Since the API has
remained static for quite some time this we never an issue. However,
going forward they should be versioned. This commit versions all
of the libraries to 1.0.0. From here on out this version must be
updated to reflect changes to the library.
Drop usage of dlopen/dlsym for libshare. There is no need to do
this because the zfs packages provide libshare. Unlike on Solaris
we are guaranteed it will be available.
This avoids possible problems with hardcoding the libshare path in
the code (e.g. when users specify a different install path via
configure options). It additionally simplifies the code which is
good for maintainability.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The sharenfs and sharesmb properties depend on the libshare library
to export datasets via NFS and SMB. This commit implements the base
libshare functionality as well as support for managing NFS shares.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The lib/libspl/include/libgen.h header file was being mistakenly
left out of the 'make dist' tarball. It just happens this doesn't
cause a build failure when creating packages because the system
libgen/h is included instead. This simply results in the following
warning due to the missing forward declaration of mkdirp().
../../lib/libzfs/libzfs_mount.c:417:3: warning: implicit declaration
of function 'mkdirp' [-Wimplicit-function-declaration]
The .get_sb callback has been replaced by a .mount callback
in the file_system_type structure. When using the new
interface the caller must now use the mount_nodev() helper.
Unfortunately, the new interface no longer passes the vfsmount
down to the zfs layers. This poses a problem for the existing
implementation because we currently save this pointer in the
super block for latter use. It provides our only entry point
in to the namespace layer for manipulating certain mount options.
This needed to be done originally to allow commands like
'zfs set atime=off tank' to work properly. It also allowed me
to keep more of the original Solaris code unmodified. Under
Solaris there is a 1-to-1 mapping between a mount point and a
file system so this is a fairly natural thing to do. However,
under Linux they many be multiple entries in the namespace
which reference the same filesystem. Thus keeping a back
reference from the filesystem to the namespace is complicated.
Rather than introduce some ugly hack to get the vfsmount and
continue as before. I'm leveraging this API change to update
the ZFS code to do things in a more natural way for Linux.
This has the upside that is resolves the compatibility issue
for the long term and fixes several other minor bugs which
have been reported.
This commit updates the code to remove this vfsmount back
reference entirely. All modifications to filesystem mount
options are now passed in to the kernel via a '-o remount'.
This is the expected Linux mechanism and allows the namespace
to properly handle any options which apply to it before passing
them on to the file system itself.
Aside from fixing the compatibility issue, removing the
vfsmount has had the benefit of simplifying the code. This
change which fairly involved has turned out nicely.
Closes#246Closes#217Closes#187Closes#248Closes#231
The security_inode_init_security() function now takes an additional
qstr argument which must be passed in from the dentry if available.
Passing a NULL is safe when no qstr is available the relevant
security checks will just be skipped.
Closes#246Closes#217Closes#187
The inode eviction should unmap the pages associated with the inode.
These pages should also be flushed to disk to avoid the data loss.
Therefore, use truncate_setsize() in evict_inode() to release the
pagecache.
The API truncate_setsize() was added in 2.6.35 kernel. To ensure
compatibility with the old kernel, the patch defines its own
truncate_setsize function.
Signed-off-by: Prasad Joshi <pjoshi@stec-inc.com>
Closes#255
Some disks with internal sectors larger than 512 bytes (e.g., 4k) can
suffer from bad write performance when ashift is not configured
correctly. This is caused by the disk not reporting its actual sector
size, but a sector size of 512 bytes. The drive may behave this way
for compatibility reasons. For example, the WDC WD20EARS disks are
known to exhibit this behavior.
When creating a zpool, ZFS takes that wrong sector size and sets the
"ashift" property accordingly (to 9: 1<<9=512), whereas it should be
set to 12 for 4k sectors (1<<12=4096).
This patch allows an adminstrator to manual specify the known correct
ashift size at 'zpool create' time. This can significantly improve
performance in certain cases. However, it will have an impact on your
total pool capacity. See the updated ashift property description
in the zpool.8 man page for additional details.
Valid values for the ashift property range from 9 to 17 (512B-128KB).
Additionally, you may set the ashift to 0 if you wish to auto-detect
the sector size based on what the disk reports, this is the default
behavior. The most common ashift values are 9 and 12.
Example:
zpool create -o ashift=12 tank raidz2 sda sdb sdc sdd
Closes#280
Original-patch-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The previous commit 8a7e1ceefa wasn't
quite right. This check applies to both the user and kernel space
build and as such we must make sure it runs regardless of what
the --with-config option is set too.
For example, if --with-config=kernel then the autoconf test does
not run and we generate build warnings when compiling the kernel
packages.
Gcc versions 4.3.2 and earlier do not support the compiler flag
-Wno-unused-but-set-variable. This can lead to build failures
on older Linux platforms such as Debian Lenny. Since this is
an optional build argument this changes add a new autoconf check
for the option. If it is supported by the installed version of
gcc then it is used otherwise it is omited.
See commit's 12c1acde76 and
79713039a2 for the reason the
-Wno-unused-but-set-variable options was originally added.
Sending pools with dedup results in a segfault due to a Solaris
portability issue. Under Solaris the pipe(2) library call
creates a bidirectional data channel. Unfortunately, on Linux
pipe(2) call creates unidirection data channel. The fix is to
use the socketpair(2) function to create the expected
bidirectional channel.
Seth Heeren did the original leg work on this issue for zfs-fuse.
We finally just rediscovered the same portability issue and
dfurphy was able to point me at the original issue for the fix.
Closes#268
This change fixes a kernel panic which would occur when resizing
a dataset which was not open. The objset_t stored in the
zvol_state_t will be set to NULL when the block device is closed.
To avoid this issue we pass the correct objset_t as the third arg.
The code has also been updated to correctly notify the kernel
when the block device capacity changes. For 2.6.28 and newer
kernels the capacity change will be immediately detected. For
earlier kernels the capacity change will be detected when the
device is next opened. This is a known limitation of older
kernels.
Online ext3 resize test case passes on 2.6.28+ kernels:
$ dd if=/dev/zero of=/tmp/zvol bs=1M count=1 seek=1023
$ zpool create tank /tmp/zvol
$ zfs create -V 500M tank/zd0
$ mkfs.ext3 /dev/zd0
$ mkdir /mnt/zd0
$ mount /dev/zd0 /mnt/zd0
$ df -h /mnt/zd0
$ zfs set volsize=800M tank/zd0
$ resize2fs /dev/zd0
$ df -h /mnt/zd0
Original-patch-by: Fajar A. Nugraha <github@fajar.net>
Closes#68Closes#84
The uid_t on most systems is in fact and unsigned 32-bit value.
This is almost always correct, however you could compile your
kernel to use an unsigned 16-bit value for uid_t. In practice
I've never encountered a distribution which does this so I'm
willing to overlook this corner case for now.
Closes#165
Disable the gethostid() override for Solaris behavior because Linux systems
implement the POSIX standard in a way that allows a negative result.
Mask the gethostid() result to the lower four bytes, like coreutils does in
/usr/bin/hostid, to prevent junk bits or sign-extension on systems that have an
eight byte long type. This can cause a spurious hostid mismatch that prevents
zpool import on 64-bit systems.
Having MAXOFFSET_T defined to 0x7fffffffl was artificially limiting
the maximum file size on 32-bit systems. In reality MAXOFFSET_T is
used when working with 'long long' types and as such we now define
it as LLONG_MAX. This resolves the 2GB file size limit for files
and additionally allows zvols greater than 2GB on 32-bit systems.
Closes#136Closes#81
As of gcc-4.6 the option -Wunused-but-set-variable is enabled by
default. While this is a useful warning there are numerous places
in the ZFS code when a variable is set and then only checked in an
ASSERT(). To avoid having to update every instance of this in the
code we now set -Wno-unused-but-set-variable to suppress the warning.
Additionally, when building with --enable-debug and -Werror set these
warning also become fatal. We can reevaluate the suppression of these
error at a later time if it becomes an issue. For now we are basically
just reverting to the previous gcc behavior.
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.
Older glibc <sys/mount.h> headers did not define all the available
umount2(2) flags. Both MNT_FORCE and MNT_DETACH are supported in the
kernel back to 2.4.11 so we define them correctly if they are missing.
Closes#95
Compiling with 'LDFLAGS=-Wl,--as-needed' exposed the fact that
there were some library linking problems introduced by mount_zfs.
In particular, the libzfs library does use nvpair symbols, and
mount_zfs contains no dependencies on libzpool.
Closes#161Closes#162
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.
Because we are dependent of the system mount/umount utilities to
ensure correct mtab locking, we should not suppress their error
output. During a successful mount/umount they will be silent,
but during a failure the error message they print is the only sure
way to know why a mount failed. This is because the (u)mount(8)
return code does not contain the result of the system call issued.
The only way to clearly idenify why thing failed is to rely on
the error message printed by the tool.
Longer term once libmount is available we can issue the mount/umount
system calls within the tool and still be ensured correct mtab locking.
Closed#107
Several issues related to strange mount/umount behavior were reported
and this commit should address most of them. The original idea was
to put in place a zfs mount helper (mount.zfs). This helper is used
to enforce 'legacy' mount behavior, and perform any extra mount argument
processing (selinux, zfsutil, etc). This helper wasn't ready for the
0.6.0-rc1 release but with this change it's functional but needs to
extensively tested.
This change addresses the following open issues.
Closes#101Closes#107Closes#113Closes#115Closes#119
The libspl and libzpool libraries were missing from the libzfs
Makefile.am. They should be explicitly listed to avoid build
issues when compiling static libraries and binaries.
Additionally, ensure libzpool is built before libzfs because
libzfs is dependent on libzpool. This was also exposed as an
issue when forcing static linking.
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
There are three improvements here to 'zpool import' proposed by Fajar
in Github issue #98. They are all good so I'm commiting all three.
1) Add descriptions for "hpet" and "core" blacklist entries.
2) Add "core" to the blacklist, as described in the issue accessing
this device will crash Xen dom0.
3) Refine probing behavior to use fstatat64(). This allows us to
determine if a device is a block device or a regular file without
having to open it. This is the safest appraoch when probing /dev/
because the simple act of opening a device may have unexpected
consequences.
Closes#98
Until code is added to support automatically sharing datasets
we should return success instead of failure. This prevents the
command line tools from returning a non-zero error code. While
a user likely won't notice this, test scripts like zconfig.sh
do and correctly fail because of it.
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 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.
It turns out that older versions of the glibc headers do not
properly define MS_DIRSYNC despite it being explicitly mentioned
in the man pages. They instead call it S_WRITE, so for system
where this is not correct defined map MS_DIRSYNC to S_WRITE.
At the time of this commit both Ubuntu Lucid, and Debian Squeeze
both use the out of date glibc headers.
As for MS_REC this field is also not available in the older headers.
Since there is no obvious mapping in this case we simply disable
the recursive mount option which used it.
The inclusion on dlsym(), dlopen(), and dlclose() symbols require
us to link against the dl library. Be careful to add the flag to
both the libzfs library and the commands which depend on the library.
These two warnings in libefi serve no real purpose. When running
without DEBUG they are already supressed, and even when DEBUG is
enabled all they indicate is the device doesn't already have an
EFI label. For a Linux machine this is probably the common case.
The Linux specific file operations have all been located in the
file zpl_file.c. These functions primarily rely on the reworked
zfs_* functions to do their job. They are also responsible for
converting the possible Solaris style error codes to negative
Linux errors.
This first zpl_* commit also includes a common zpl.h header with
minimal entries to register the Linux specific hooks. In also
adds all the new zpl_* file to the Makefile.in. This is not a
standalone commit, you required the following zpl_* commits.
This code is used for snapshot and heavily leverages Solaris
functionality we do not want to reimplement. These files have
been removed, including references to them, and will be replaced
by a zfs_snap.c/zpl_snap.c implementation which handles snapshots.
This code originates in OpenSolaris and was modified by KQ Infotech
to be compatible with Linux. While supporting uios in the short
term is useful to get something working this is not an abstraction
we want to keep. This code is expected to be short lived and
removed as soon as all the remaining uio based APIs and updated.
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.
By design the zfs utility is supposed to handle mounting and unmounting
a zfs filesystem. We could allow zfs to do this directly. There are
system calls available to mount/umount a filesystem. And there are
library calls available to manipulate /etc/mtab. But there are a
couple very good reasons not to take this appraoch... for now.
Instead of directly calling the system and library calls to (u)mount
the filesystem we fork and exec a (u)mount process. The principle
reason for this is to delegate the responsibility for locking and
updating /etc/mtab to (u)mount(8). This ensures maximum portability
and ensures the right locking scheme for your version of (u)mount
will be used. If we didn't do this we would have to resort to an
autoconf test to determine what locking mechanism is used.
The downside to using mount(8) instead of mount(2) is that we lose
the exact errno which was returned by the kernel. The return code
from mount(8) provides some insight in to what went wrong but it
not quite as good. For the moment this is translated as a best
guess in to a errno for the higher layers of zfs.
In the long term a shared library called libmount is under development
which provides a common API to address the locking and errno issues.
Once the standard mount utility has been updated to use this library
we can then leverage it. Until then this is the only safe solution.
http://www.kernel.org/pub/linux/utils/util-linux/libmount-docs/index.html
Recently helper functions were added to libzfs_util to load a kernel
module or execute a process. Initially this functionality was limited
to libzfs but it has become clear there will be other consumers. This
change opens up the interface so it may be used where appropriate.
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.
These compiler warnings were introduced when code which was
previously #ifdef'ed out by HAVE_ZPL was re-added for use
by the posix layer. All of the following changes should be
obviously correct and will cause no semantic changes.
For while now mkdirp has been built as part of libspl however
the protoype was never added to libgen.h. This went unnoticed
until enabling the mount support which uses mkdirp().
Specifically, this fixes the two following errors in zdb when a pool
is composed of block devices:
1) 'Value too large for defined data type' when running 'zdb <dataset>'.
2) 'character device required' when running 'zdb -l <block-device>'.
Signed-off-by: Ricardo M. Correia <ricardo.correia@oracle.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
If libblkid does not contain ZFS support, then 'zpool import' will scan
all block devices in /dev/ to determine which ones are components of a
ZFS filesystem. It does this by opening all the devices and stat'ing
them to determine which ones are block devices. If the device turns
out not to be a block device it is skipped.
Usually, this whole process is pretty harmless (although slow). But
there are certain devices in /dev/ which must be handled in a very
specific way or your system may crash. For example, if /dev/watchdog
is simply opened the watchdog timer will be started and your system
will panic when the timer expires.
It turns out the /dev/hpet causes similiar problems although only when
accessed under a virtual machine. For some reason accessing /dev/hpet
causes qemu to crash. To address this issue this commit adds /dev/hpet
to the device blacklist, it will be skipped solely based on its name.
This commit fixes a sign extension bug affecting l2arc devices. Extremely
large offsets may be passed down to the low level block device driver on
reads, generating errors similar to
attempt to access beyond end of device
sdbi1: rw=14, want=36028797014862705, limit=125026959
The unwanted sign extension occurrs because the function arc_read_nolock()
stores the offset as a daddr_t, a 32-bit signed int type in the Linux kernel.
This offset is then passed to zio_read_phys() as a uint64_t argument, causing
sign extension for values of 0x80000000 or greater. To avoid this, we store
the offset in a uint64_t.
This change also changes a few daddr_t struct members to uint64_t in the libspl
headers to avoid similar bugs cropping up in the future. We also add an ASSERT
to __vdev_disk_physio() to check for invalid offsets.
Closes#66
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Some sudo configurations may not include /sbin in the PATH.
libzfs_load_module() currently does not call modprobe with an absolute path, so
it may fail under such configurations if called under sudo. This change adds
the absolute path to modprobe so we no longer rely on how PATH is set.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
zpool status displays abbreviated vdev names without leading path components
and, in the case of whole disks, without partition information. Also, the
zpool subcommands 'create' and 'add' support using shorthand devices names
without qualified paths. Prior to this change, however, removing a device
generally required specifying its name as it is stored in the vdev label. So
while zpool status might list a cache disk with a name like A16, removing it
would require a full path such as /dev/disk/zpool/A16-part1, which is
non-intuitive.
This change adds support for shorthand device names with the remove subcommand
so one can simply type, for example,
zpool remove tank A16
A consequence of this change is that including the partition information when
removing a whole-disk vdev now results in an error. While this is arguably the
correct behavior, it is a departure from how zpool previously worked in this
project.
This change removes the only reference to ctd_check_path(), so that function is
also removed to avoid compiler warnings.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This change adds two helper functions for working with vdev names and paths.
zfs_resolve_shortname() resolves a shorthand vdev name to an absolute path
of a file in /dev, /dev/disk/by-id, /dev/disk/by-label, /dev/disk/by-path,
/dev/disk/by-uuid, /dev/disk/zpool. This was previously done only in the
function is_shorthand_path(), but we need a general helper function to
implement shorthand names for additional zpool subcommands like remove.
is_shorthand_path() is accordingly updated to call the helper function.
There is a minor change in the way zfs_resolve_shortname() tests if a file
exists. is_shorthand_path() effectively used open() and stat64() to test for
file existence, since its scope includes testing if a device is a whole disk
and collecting file status information. zfs_resolve_shortname(), on the other
hand, only uses access() to test for existence and leaves it to the caller to
perform any additional file operations. This seemed like the most general and
lightweight approach, and still preserves the semantics of is_shorthand_path().
zfs_append_partition() appends a partition suffix to a device path. This
should be used to generate the name of a whole disk as it is stored in the vdev
label. The user-visible names of whole disks do not contain the partition
information, while the name in the vdev label does. The code was lifted from
the function make_disks(), which now just calls the helper function. Again,
having a helper function to do this supports general handling of shorthand
names in the user interface.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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.
This commit modifies libzfs_init() to attempt to load the zfs kernel module if
it is not already loaded. This is done to simplify initialization by letting
users simply import their zpools without having to first load the module.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Under Solaris, the slice number is chopped off when displaying the device name
if the vdev is a whole disk. Under Linux we should similarly discard the
partition number. This commit adds the logic to perform the name truncation
for devices ending in -partX, XpX, or X, where X is a string of digits. The
second case handles devices like md0p0. The third case is limited to scsi and
ide disks, i.e. those beginning with "sd" or "hd", in order to avoid stripping
the number from names like "loop0".
This commit removes the Solaris-specific code for removing slices, since we no
longer reasonably expect our changes to be merged in upstream. The partition
stripping code was moved off to a helper function to improve readability.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Top-level vdev names in zpool status output should follow a <type-id> naming
convention. In the case of raidz devices, the type portion of the name was
missing.
This commit fixes a bug in zpool_vdev_name() where in this snprintf call
(void) snprintf(buf, sizeof (buf), "%s-%llu", path,
(u_longlong_t)id);
buf and path may point to the same location. The result is that buf ends up
containing only the "-id" part. This only occurred for raidz devices because
the code for appending the parity level to the type string stored its result in
buf then set path to point there. To fix this we allocate a new temporary
buffer on the stack instead of reusing buf.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#57
The zfs package supports the option --with-config=srpm which
is used to bootstrap configure to allow the 'make srpm' target
to work. This has the advantage of allowing creation of source
rpms without having all your -devel packages installed. This
source package can then be feed back in to an automated build
farm which only installs the required packages listed by the
srpm. This ensures that all proper dependencies are expressed
by the source package, because if they are not you will get
configure/build failures.
The trouble here is that --with-config=srpm prevents the
architecture check from running resulting in TARGET_ASM_DIR
being set to the default asm-generic. The 'make dist' rule
then fails because there is no asm-generic/atomic.S file
because it is generated at build time. To handle this I
have added an empty file asm-generic/atomic.S simply as a
place holder for 'make dist'.
Under Ubuntu 10.04 the default compiler flags include -Wformat
and -Wformat-security which cause the above warning. In particular,
cases where "%s" was forgotten as part of the format specifier.
https://wiki.ubuntu.com/CompilerFlags
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 GIT file was removed from the tree because I have stopped
using TopGit. Because of this is must also be removed from
the top level Makefile.am as will as the zfs.spec.in file
which referenced it.
Fix type in lib/libzpool/Makefile.am which was preventing
the needed zrlock.h header from being included by 'make dist'.
I simply had the name wrong in the Makefile.am.
Regenerated autogen.sh build products.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
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>
This topic branch contains required changes to the user space
utilities to allow them to integrate cleanly with Linux.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This topic branch contains all the changes needed to integrate the user
side zfs tools with Linux style devices. Primarily this includes fixing
up the Solaris libefi library to be Linux friendly, and integrating with
the libblkid library which is provided by e2fsprogs.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Track various large hunks which have been dropped simply
because they are not relevant to this port.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Solaris recently introduced the idea of drive topology because
where a drive is located does matter. I have already handled
this with udev/blkid integration under Linux so I'm hopeful
this case can simply be removed but for now I've just stubbed
out what is needed in libspl and commented out the rest here.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The upstream ZFS code has correctly moved to a faster native sha2
implementation. Unfortunately, under Linux that's going to be a little
problematic so we revert the code to the more portable version contained
in earlier ZFS releases. Using the native sha2 implementation in Linux
is possible but the API is slightly different in kernel version user
space depending on which libraries are used. Ideally, we need a fast
implementation of SHA256 which builds as part of ZFS this shouldn't be
that hard to do but it will take some effort.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
All changes needed for the libspl layer. This includes modifications
to files directly copied from OpenSolaris and the addition of new
files needed to fill in the gaps.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This branch contains the majority of the changes required to cleanly
intergrate with Linux style special devices (/dev/zfs). Mainly this
means dropping all the Solaris style callbacks and replacing them
with the Linux equivilants.
This patch also adds the onexit infrastructure needed to track
some minimal state between ioctls. Under Linux it would be easy
to do this simply using the file->private_data. But under Solaris
they apparent need to pass the file descriptor as part of the ioctl
data and then perform a lookup in the kernel. Once again to keep
code change to a minimum I've implemented the Solaris solution.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The ZFS update to onnv_141 brought with it support for a
security label attribute called mlslabel. This feature
depends on zones to work correctly and thus I am disabling
it under Linux. Equivilant functionality could be added
at some point in the future.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This topic branch leverages the Solaris style FMA call points
in ZFS to create a user space visible event notification system
under Linux. This new system is called zevent and it unifies
all previous Solaris style ereports and sysevent notifications.
Under this Linux specific scheme when a sysevent or ereport event
occurs an nvlist describing the event is created which looks almost
exactly like a Solaris ereport. These events are queued up in the
kernel when they occur and conditionally logged to the console.
It is then up to a user space application to consume the events
and do whatever it likes with them.
To make this possible the existing /dev/zfs ABI has been extended
with two new ioctls which behave as follows.
* ZFS_IOC_EVENTS_NEXT
Get the next pending event. The kernel will keep track of the last
event consumed by the file descriptor and provide the next one if
available. If no new events are available the ioctl() will block
waiting for the next event. This ioctl may also be called in a
non-blocking mode by setting zc.zc_guid = ZEVENT_NONBLOCK. In the
non-blocking case if no events are available ENOENT will be returned.
It is possible that ESHUTDOWN will be returned if the ioctl() is
called while module unloading is in progress. And finally ENOMEM
may occur if the provided nvlist buffer is not large enough to
contain the entire event.
* ZFS_IOC_EVENTS_CLEAR
Clear are events queued by the kernel. The kernel will keep a fairly
large number of recent events queued, use this ioctl to clear the
in kernel list. This will effect all user space processes consuming
events.
The zpool command has been extended to use this events ABI with the
'events' subcommand. You may run 'zpool events -v' to output a
verbose log of all recent events. This is very similar to the
Solaris 'fmdump -ev' command with the key difference being it also
includes what would be considered sysevents under Solaris. You
may also run in follow mode with the '-f' option. To clear the
in kernel event queue use the '-c' option.
$ sudo cmd/zpool/zpool events -fv
TIME CLASS
May 13 2010 16:31:15.777711000 ereport.fs.zfs.config.sync
class = "ereport.fs.zfs.config.sync"
ena = 0x40982b7897700001
detector = (embedded nvlist)
version = 0x0
scheme = "zfs"
pool = 0xed976600de75dfa6
(end detector)
time = 0x4bec8bc3 0x2e5aed98
pool = "zpios"
pool_guid = 0xed976600de75dfa6
pool_context = 0x0
While the 'zpool events' command is handy for interactive debugging
it is not expected to be the primary consumer of zevents. This ABI
was primarily added to facilitate the addition of a user space
monitoring daemon. This daemon would consume all events posted by
the kernel and based on the type of event perform an action. For
most events simply forwarding them on to syslog is likely enough.
But this interface also cleanly allows for more sophisticated
actions to be taken such as generating an email for a failed drive.
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.
We should not put a 4k maxpathlen buffer on the stack, instead
locate it to the heap. Even in user space we run ztest with 8K
stacks to verify correctness
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Certain function must never be automatically inlined by gcc because
they are stack heavy or called recursively. This patch flags all
such functions I've found as 'noinline' to prevent gcc from making
the optimization.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This is a portability change which removes the dependence of the Solaris
thread library. All locations where Solaris thread API was used before
have been replaced with equivilant Solaris kernel style thread calls.
In user space the kernel style threading API is implemented in term of
the portable pthreads library. This includes all threads, mutexs,
condition variables, reader/writer locks, and taskqs.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This look like a typo. The intention was to use strlcat() however
strncat() was used instead accidentally this may lead to a buffer
overflow. This was caught by gcc -D_FORTIFY_SOURCE=2.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Do not use zmod.h in userspace.
This has also been filed with the ZFS team. It makes the userspace
libzpool code use the zlib API, instead of the Solaris-only and
non-standard zmod.h. The zlib API is almost identical and is a de
facto standard, so this is a no-brainer.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
1) In vn_open(), if fstat64() returned an error, the real errno
was being obscured by calling close().
2) Add error handling for both pwrite64() calls in vn_rdwr().
Signed-off-by: Ricardo M. Correia <Ricardo.M.Correia@Sun.COM>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Remove deadcode. It's possible the code should be in use
somewhere, but as the source code is laid out it currently
is not.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Use constructor attribute on non-Solaris platforms.
The #pragma init/fini ->__attribute__((constructor/destructor))
conversions, these should go upstream.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Resolve issues uncovered by -D_FORTIFY_SOURCE=2, the default redhat
macro's file adds this option to the cflags. This causes warnings
of the following type designed to keep the developer honest:
warning: ignoring return value of 'foo', declared
with attribute warn_unused_result
The short term fix is to wrap these calls in VERIFY() to check the
return code. The code was already assusing these would never fail.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix non-c90 compliant code, for the most part these changes
simply deal with where a particular variable is declared.
Under c90 it must alway be done at the very start of a block.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
