Daniel Verite [Fri, 8 Jun 2012 20:30:39 +0000 (22:30 +0200)]
Include <locale.h> to avoid error: 'LC_ALL' undeclared.
When compiling ZFS with CFLAGS=-O0 it will trigger the following error.
Resolve the issue by properly including locale.h.
../../cmd/mount_zfs/mount_zfs.c: In function 'main':
../../cmd/mount_zfs/mount_zfs.c:318:2: warning: implicit declaration
of function 'setlocale' [-Wimplicit-function-declaration]
../../cmd/mount_zfs/mount_zfs.c:318:19: error: 'LC_ALL' undeclared
(first use in this function)
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #724
Richard Yao [Wed, 6 Jun 2012 17:08:00 +0000 (17:08 +0000)]
Linux 3.4 compat, d_make_root() replaces d_alloc_root()
torvalds/linux@adc0e91ab142abe93f5b0d7980ada8a7676231fe introduced
introduced d_make_root() as a replacement for d_alloc_root(). Further
commits appear to have removed d_alloc_root() from the Linux source
tree. This causes the following failure:
error: implicit declaration of function 'd_alloc_root'
[-Werror=implicit-function-declaration]
To correct this we update the code to use the current d_make_root()
interface for readability. Then we introduce an autotools check
to determine if d_make_root() is available. If it isn't then we
define some compatibility logic which used the older d_alloc_root()
interface.
Signed-off-by: Richard Yao <ryao@gentoo.org> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #776
The logbias option is not taken into account when writing to ZVOLs. We fix
that by using the same logic as in the zfs filesystem write code
(see zfs_log.c).
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #774
Ned Bass [Tue, 5 Jun 2012 19:45:37 +0000 (12:45 -0700)]
Improve CONFIG_DEBUG_LOCK_ALLOC error message
The configure script error message for kernels built with
CONFIG_DEBUG_LOCK_ALLOC may give the impression that the issue is
strictly with license compliance. To avoid confusion add some words
indicating that the linking stage will fail if the build continues.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #773
Brian Behlendorf [Thu, 31 May 2012 19:42:51 +0000 (12:42 -0700)]
Improve 'zpool import' EBUSY error message
When a device is already open O_EXCL by another process the
`zpool import` will correctly fail. However, the default failure
message isn't very helpful. It may in fact be harmful if you
take its advise and destroy your pool.
cannot import 'tank': pool is busy
Destroy and re-create the pool from
a backup source.
Improve the error message in the EBUSY case to simply print a
message indicating that the devices are current in use. The user
will need to manually identify which process has the device open
exclusively and why.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Fri, 25 May 2012 21:52:56 +0000 (14:52 -0700)]
Add /dev/mapper/ to search path
When creating pools short device names may be used when those
devices appear in certain well known locations under /dev/.
This change adds /dev/mapper/ to that list.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ned A. Bass [Sat, 21 Apr 2012 00:32:30 +0000 (17:32 -0700)]
Add vdev_id for JBOD-friendly udev aliases
vdev_id parses the file /etc/zfs/vdev_id.conf to map a physical path
in a storage topology to a channel name. The channel name is combined
with a disk enclosure slot number to create an alias that reflects the
physical location of the drive. This is particularly helpful when it
comes to tasks like replacing failed drives. Slot numbers may also be
re-mapped in case the default numbering is unsatisfactory. The drive
aliases will be created as symbolic links in /dev/disk/by-vdev.
The only currently supported topologies are sas_direct and sas_switch:
o sas_direct - a channel is uniquely identified by a PCI slot and a
HBA port
o sas_switch - a channel is uniquely identified by a SAS switch port
A multipath mode is supported in which dm-mpath devices are handled by
examining the first running component disk, as reported by 'multipath
-l'. In multipath mode the configuration file should contain a
channel definition with the same name for each path to a given
enclosure.
vdev_id can replace the existing zpool_id script on systems where the
storage topology conforms to sas_direct or sas_switch. The script
could be extended to support other topologies as well. The advantage
of vdev_id is that it is driven by a single static input file that can
be shared across multiple nodes having a common storage toplogy.
zpool_id, on the other hand, requires a unique /etc/zfs/zdev.conf per
node and a separate slot-mapping file. However, zpool_id provides the
flexibility of using any device names that show up in
/dev/disk/by-path, so it may still be needed on some systems.
vdev_id's functionality subsumes that of the sas_switch_id script, and
it is unlikely that anyone is using it, so sas_switch_id is removed.
Finally, /dev/disk/by-vdev is added to the list of directories that
'zpool import' will scan.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #713
Brian Behlendorf [Mon, 21 May 2012 19:59:58 +0000 (12:59 -0700)]
Extend CONFIG_DEBUG_LOCK_ALLOC check
The CONFIG_DEBUG_LOCK_ALLOC check at configure time was added to
detect when mutex_lock() is defined as a GPL-only symbol. However,
the check as written only inferred this from this configuration
setting, it never actually checked. This change introduces that
missing check to prevent false positives.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Mon, 30 Apr 2012 21:24:39 +0000 (14:24 -0700)]
Revert "Disable direct reclaim on zvols"
This reverts commit ce90208cf9e04df966429f115d8831371ea9afce. This
change was observed to cause problems when using a zvol to back a VM
under 2.6.32.59 kernels. This issue was filed as #710.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #342
Issue #710
Brian Behlendorf [Mon, 30 Apr 2012 19:01:49 +0000 (12:01 -0700)]
Linux 3.3 compat, iops->create()/mkdir()/mknod()
The mode argument of iops->create()/mkdir()/mknod() was changed from
an 'int' to a 'umode_t'. To prevent a compiler warning an autoconf
check was added to detect the API change and then correctly set a
zpl_umode_t typedef. There is no functional change.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #701
Richard Yao [Mon, 16 Apr 2012 10:56:20 +0000 (06:56 -0400)]
Disable direct reclaim on zvols
Previously, it was possible for the direct reclaim path to be invoked
when a write to a zvol was made. When a zvol is used as a swap device,
this often causes swap requests to depend on additional swap requests,
which deadlocks. We address this by disabling the direct reclaim path
on zvols.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #342
Richard Yao [Thu, 12 Apr 2012 21:22:08 +0000 (17:22 -0400)]
Update ARC memory limits to account for SLUB internal fragmentation
23bdb07d4e4c435205d25d3efdb5fef2d089ce5e updated the ARC memory limits
to be 1/2 of memory or all but 4GB. Unfortunately, these values assume
zero internal fragmentation in the SLUB allocator, when in reality, the
internal fragmentation could be as high as 50%, effectively doubling
memory usage. This poses clear safety issues, because it permits the
size of ARC to exceed system memory.
This patch changes this so that the default value of arc_c_max is always
1/2 of system memory. This effectively limits the ARC to the memory that
the system has physically installed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #660
Brian Behlendorf [Tue, 13 Mar 2012 21:29:16 +0000 (14:29 -0700)]
Integrate ARC more tightly with Linux
Under Solaris the ARC was designed to stay one step ahead of the
VM subsystem. It would attempt to recognize low memory situtions
before they occured and evict data from the cache. It would also
make assessments about if there was enough free memory to perform
a specific operation.
This was all possible because Solaris exposes a fairly decent
view of the memory state of the system to other kernel threads.
Linux on the other hand does not make this information easily
available. To avoid extensive modifications to the ARC the SPL
attempts to provide these same interfaces. While this works it
is not ideal and problems can arise when the ARC and Linux have
different ideas about when your out of memory. This has manifested
itself in the past as a spinning arc_reclaim_thread.
This patch abandons the emulated Solaris interfaces in favor of
the prefered Linux interface. That means moving the bulk of the
memory reclaim logic out of the arc_reclaim_thread and in to the
evict driven shrinker callback. The Linux VM will call this
function when it needs memory. The ARC is then responsible for
attempting to free the requested amount of memory if possible.
Several interfaces have been modified to accomidate this approach,
however the basic user space implementation remains the same.
The following changes almost exclusively just apply to the kernel
implementation.
* Removed the hdr_recl() reclaim callback which is redundant
with the broader arc_shrinker_func().
* Reduced arc_grow_retry to 5 seconds from 60. This is now used
internally in the ARC with arc_no_grow to indicate that direct
reclaim was recently performed. This typically indicates a
rapid change in memory demands which the kswapd threads were
unable to keep ahead of. As long as direct reclaim is happening
once every 5 seconds arc growth will be paused to avoid further
contributing to the existing memory pressure. The more common
indirect reclaim paths will not set arc_no_grow.
* arc_shrink() has been extended to take the number of bytes by
which arc_c should be reduced. This allows for a more granual
reduction of the arc target. Since the kernel provides a
reclaim value to the arc_shrinker_func() this value is used
instead of 1<<arc_shrink_shift.
* arc_reclaim_needed() has been removed. It was used to determine
if the system was under memory pressure and relied extensively
on Solaris specific VM interfaces. In most case the new code
just checks arc_no_grow which indicates that within the last
arc_grow_retry seconds direct memory reclaim occurred.
* arc_memory_throttle() has been updated to always include the
amount of evictable memory (arc and page cache) in its free
space calculations. This space is largely available in most
call paths due to direct memory reclaim.
* The Solaris pageout code was also removed to avoid confusion.
It has always been disabled due to proc_pageout being defined
as NULL in the Linux port.
Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Fri, 27 Apr 2012 23:20:31 +0000 (16:20 -0700)]
Add zfs_mdcomp_disable module option
Expose the zfs_mdcomp_disable variable as a module option. This
can be used to disable compression of zfs meta data which is
enabled by default. This shouldn't need to be tuned but for
most workloads, however there may be very specific instances
where it makes sense to trade disk capacity for extra cpu cycles.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Thu, 19 Apr 2012 22:55:28 +0000 (15:55 -0700)]
Illumos #1909: disk sync write perf regression when slog is used post oi_148
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Steve Gonczi <gonczi@comcast.net>
Reviewed by: Garrett D'Amore <garrett.damore@gmail.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Albert Lee <trisk@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>
Refererces to Illumos issue:
https://www.illumos.org/issues/1909
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #680
There is potential for deadlock in the l2arc_feed thread if KM_PUSHPAGE
is not used for the allocations made in l2arc_write_buffers.
Specifically, if KM_PUSHPAGE is not used for these allocations, it is
possible for reclaim to be triggered which can cause the l2arc_feed
thread to deadlock itself on the ARC_mru mutex. An example of this is
demonstrated in the following backtrace of the l2arc_feed thread:
For consistency, and because it's handy, add the 'zfs snap' alias which
was introduced by Oracle Solaris 11. This includes an update to the
man page to reflect all the available alias (snap, umount, and recv).
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #640
Martin Matuska [Sun, 8 Apr 2012 17:16:46 +0000 (13:16 -0400)]
Illumos #1346: zfs incremental receive may leave behind temporary clones
1356 zfs dataset prefetch code not working
Reviewed by: Matthew Ahrens <matt@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Approved by: Gordon Ross <gwr@nexenta.com>
References to Illumos issue:
https://www.illumos.org/issues/1346
https://www.illumos.org/issues/1356
Ported-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #647
Albert Lee [Sun, 8 Apr 2012 17:10:49 +0000 (13:10 -0400)]
Illumos #1475: zfs spill block hold can access invalid spill blkptr
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Approved by: Garrett D'Amore <garrett@nexenta.com>
References to Illumos issue:
https://www.illumos.org/issues/1475
Ported-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #648
George Wilson [Sun, 8 Apr 2012 17:23:08 +0000 (13:23 -0400)]
Illumos #1951: leaking a vdev when removing an l2cache device
1952 memory leak when adding a file-based l2arc device
1954 leak in ZFS from metaslab_group_create and zfs_ereport_checksum
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>
References to Illumos issues:
https://www.illumos.org/issues/1951
https://www.illumos.org/issues/1952
https://www.illumos.org/issues/1954
Ported-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #650
Martin Matuska [Sun, 8 Apr 2012 17:18:48 +0000 (13:18 -0400)]
OS-926: zfs panic in zfs_fill_zplprops_impl()
This change appears to be exclusive to SmartOS. It is not present in
illumos-gate but it just adds some needed error handling. This is
clearly preferable to simply ASSERTING which is what would occur
prior to the patch.
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Matt Ahrens <matt@delphix.com> Ported-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #652
Principly these symbols were exported to get access to the
dsl_prop_register/dsl_prop_unregister functions. They allow
us to cleanly register a callback which is called when a
dataset property is modified.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Gunnar Beutner [Thu, 5 Apr 2012 08:30:10 +0000 (10:30 +0200)]
Fixed a NULL pointer dereference bug in zfs_preumount
When zpl_fill_super -> zfs_domount fails (e.g. because the dataset
was destroyed before it could be successfully mounted) the subsequent
call to zpl_kill_sb -> zfs_preumount would derefence a NULL pointer.
This bug can be reproduced using this shell script:
#!/bin/sh
(
while true; do
zfs create -o mountpoint=legacz tank/bar
zfs destroy tank/bar
done
) &
(
while true; do
mount -t zfs tank/bar /mnt
umount /mnt
done
) &
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #639
Richard Yao [Tue, 3 Apr 2012 04:21:22 +0000 (00:21 -0400)]
Make Gentoo initscript use modinfo
The -l parameter to modprobe has been removed from the latest upstream
code and this change has entered Gentoo. Using modinfo as a substitute
addresses this.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #636
Richard Yao [Tue, 3 Apr 2012 00:44:42 +0000 (20:44 -0400)]
Print human readable error message for ENOENT
A cryptic error code is printed when mounting a legacy dataset to a
non-existent mountpoint. This patch changes this behavior to print
"mount point '%s' does not exist", which is similar to the error
message printed when mounting procfs.
The single quotes were added to be consistent with the existing EBUSY
error message, which is the only difference between this error message
and the one that is printed when the same condition occurs when mounting
procfs.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #633
Brian Behlendorf [Tue, 27 Mar 2012 17:10:26 +0000 (10:10 -0700)]
Properly expose the mfu ghost list kstats
Due to a typo the mru ghost lists stats were accidentally being
exposed as the mfu ghost list stats. This was harmless but
confusing since memory usage could be over reported.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Craig Sanders [Tue, 27 Mar 2012 10:37:41 +0000 (21:37 +1100)]
Remove hard-coded 80 column output
When stdout is detected to be a tty use the number of columns
specified by the terminal. If that fails fall back to a default
80 column width. In the non-tty case allow for 999 column lines.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Mon, 26 Mar 2012 17:34:55 +0000 (10:34 -0700)]
Fix executable permissions
Caught by lint, this permission change was accidentally introduced
by commit 42cb3819f1a1f536105faac81ffc150f3da90a80. Restore the
correct permissions and while I'm at it add a missing whack-bang
to config/ltmain.sh.
Brian Behlendorf [Tue, 20 Mar 2012 23:00:17 +0000 (16:00 -0700)]
Add --enable-debug-dmu-tx configure option
Allow rigorous (and expensive) tx validation to be enabled/disabled
indepentantly from the standard zfs debugging. When enabled these
checks ensure that all txs are constructed properly and that a dbuf
is never dirtied without taking the correct tx hold.
This checking is particularly helpful when adding new dmu consumers
like Lustre. However, for established consumers such as the zpl
with no known outstanding tx construction problems this is just
overhead.
--enable-debug-dmu-tx - Enable/disable validation of each tx as
--disable-debug-dmu-tx it is constructed. By default validation
is disabled due to performance concerns.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Mon, 12 Mar 2012 19:38:00 +0000 (12:38 -0700)]
Enhance a dmu_tx_dirty_buf() assertion
The following assertion is good to validate the correctness of
new DMU consumers, but it doesn't quite provide enough information.
Slightly rework the assertion so that when it is hit the actual
offending values will be included in the output.
Brian Behlendorf [Thu, 22 Mar 2012 21:47:29 +0000 (14:47 -0700)]
Account for .zfs ctldir inodes
Because the .zfs ctldir inodes are not backed by physical storage
they use a different create path which was not properly accounting
for them as used. This could result in ->nr_cached_objects()
returning 0 and cause a divide by zero error in prune_super().
In my option there's a kernel bug here too which allows this to
happen. They should either be checking for 0 or adding +1 like
they correctly do earlier in the function.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #617
Brian Behlendorf [Fri, 11 Nov 2011 07:15:53 +0000 (12:45 +0530)]
Add .zfs control directory
Add support for the .zfs control directory. This was accomplished
by leveraging as much of the existing ZFS infrastructure as posible
and updating it for Linux as required. The bulk of the core
functionality is now all there with the following limitations.
*) The .zfs/snapshot directory automount support requires a 2.6.37
or newer kernel. The exception is RHEL6.2 which has backported
the d_automount patches.
*) Creating/destroying/renaming snapshots with mkdir/rmdir/mv
in the .zfs/snapshot directory works as expected. However,
this functionality is only available to root until zfs
delegations are finished.
* mkdir - create a snapshot
* rmdir - destroy a snapshot
* mv - rename a snapshot
The following issues are known defeciences, but we expect them to
be addressed by future commits.
*) Add automount support for kernels older the 2.6.37. This should
be possible using follow_link() which is what Linux did before.
*) Accessing the .zfs/snapshot directory via NFS is not yet possible.
The majority of the ground work for this is complete. However,
finishing this work will require resolving some lingering
integration issues with the Linux NFS kernel server.
*) The .zfs/shares directory exists but no futher smb functionality
has yet been implemented.
Contributions-by: Rohan Puri <rohan.puri15@gmail.com> Contributiobs-by: Andrew Barnes <barnes333@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #173
Brian Behlendorf [Thu, 23 Feb 2012 23:32:51 +0000 (15:32 -0800)]
Add zio constructor/destructor
Add a standard zio constructor and destructor. Normally, this is
done to reduce to cost of allocating a new structure by reducing
expensive operations such as memory allocations. However, in this
case none of the operations moved out of zio_create() were really
very expensive.
This change was principly made as a debug patch (and workaround)
for a zio_destroy() race. The is good evidence that zio_create()
is reinitializing a mutex which is really still in use by another
thread. This would completely explain the observed symptoms in
the issue report.
This patch doesn't fix the root cause of the race, but it should
make it less likely by only initializing the mutex once in the
constructor. Also, this particular flaw might have gone unnoticed
in other zfs implementations due to the specific implementation
details of Linux ticket spinlocks.
Once the real root cause is determined and resolved this change
can be safely reverted. Until then this should help workaround
the issue.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #496
Brian Behlendorf [Wed, 21 Mar 2012 18:51:27 +0000 (11:51 -0700)]
Revert "Add zio constructor/destructor"
This patch was slightly flawed and allowed for zio->io_logical
to potentially not be reinitialized for a new zio. This could
lead to assertion failures in specific cases when debugging is
enabled (--enable-debug) and I/O errors are encountered. It
may also have caused problems when issues logical I/Os.
Since we want to make sure this workaround can be easily removed
in the future (when we have the real fix). I'm reverting this
change and applying a new version of the patch which includes
the zio->io_logical fix.
Brian Behlendorf [Wed, 14 Mar 2012 19:36:49 +0000 (12:36 -0700)]
Add missing NULL in zpl_xattr_handlers
The xattr_resolve_name() helper function expects the registered
list of xattr handlers to be NULL terminated. This NULL was
accidentally missing which could result in a NULL dereference.
Interestingly this issue only manifested itself on certain 32-bit
systems. Presumably on 64-bit kernels we just always happen to
get lucky and the memory following the structure is zeroed.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #594
Gregor Kopka [Wed, 14 Mar 2012 13:34:00 +0000 (14:34 +0100)]
Use stderr for 'no pools/datasets available' error
The 'zfs list' and 'zpool list' commands output the message
'no datasets/pools available' to stdout. This should go to
stderr and only the available datasets/pools should go to
stdout. Returning nothing to stdout is expected behavior
when there is nothing to list.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #581
Add a SA interface which allows us to release the spill block
from a SA handle without destroying the handle. This is useful
because we can then ensure that a copy of the dirty spill block
is not made at sync time due to the extra hold. Susequent calls
to sa_update() or sa_lookup() with transparently refetch the
spill block dbuf from the ARC hash.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Thu, 23 Feb 2012 23:32:51 +0000 (15:32 -0800)]
Add zio constructor/destructor
Add a standard zio constructor and destructor. Normally, this is
done to reduce to cost of allocating a new structure by reducing
expensive operations such as memory allocations. However, in this
case none of the operations moved out of zio_create() were really
very expensive.
This change was principly made as a debug patch (and workaround)
for a zio_destroy() race. The is good evidence that zio_create()
is reinitializing a mutex which is really still in use by another
thread. This would completely explain the observed symptoms in
the issue report.
This patch doesn't fix the root cause of the race, but it should
make it less likely by only initializing the mutex once in the
constructor. Also, this particular flaw might have gone unnoticed
in other zfs implementations due to the specific implementation
details of Linux ticket spinlocks.
Once the real root cause is determined and resolved this change
can be safely reverted. Until then this should help workaround
the issue.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #496
Richard Yao [Tue, 28 Feb 2012 21:23:16 +0000 (16:23 -0500)]
Fix distribution detection
Improve the distribution detection by moving the tests for
distribution specific files first. The Ubuntu and Debian
checks are left for last because they are the least likely
to be unique. This is particularly true in the case of Debian
since so many distributions are based on Debian.
Since this is currently only used to identify the correct
packaging method for this system the result in many instances
is simply cosmetic.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ned Bass [Wed, 29 Feb 2012 18:08:20 +0000 (10:08 -0800)]
Align parition end on 1 MiB boundary
Some devices have exhibited sensitivity to the ending alignment of
partitions. In particular, even if the first partition begins at 1
MiB, we have seen many sd driver task abort errors with certain SSDs
if the first partition doesn't end on a 1 MiB boundary. This occurs
when the vdev label is read during pool creation or importation and
causes a delay of about 30 seconds per device. It can also be
simulated with dd when the pool isn't imported:
dd if=/dev/sda1 of=/dev/null bs=262144 count=1
For the record, this problem was observed with SMARTMOD
SG9XCA2E200GE01 200GB SSDs. Unfortunately I don't have a good
explanation for this behavior. It seems to have something to do with
highly fragmented single-sector requests being issued to the device,
which it may not support. With end-aligned partitions at least
page-sized requests were queued and issued to the driver according
to blktrace. In any case, aligning the partition end is a fairly
innocuous work-around, wasting at most 1 MiB of space.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #574
A private SA handle must be used to ensure we can drop the dbuf
hold on the spill block prior to calling dmu_tx_commit(). If we
call dmu_tx_commit() before sa_handle_destroy(), then our hold
will trigger a copy of the dbuf to be made. This is done to
prevent data from leaking in to the syncing txg. As a result
the original dirty spill block will remain cached.
Additionally, relying on the shared zp->z_sa_hdl is unsafe in
the xattr context because the znode may be asynchronously dropped
from the cache. It's far safer and simpler just to use a private
handle for xattrs. Plus any additional overhead is offset by
the avoidance of the previously mentioned memory copy.
These forever dirty buffers can be noticed in the arcstats under
the anon_size. On a quiescent system the value should be zero.
Without this fix and a SA xattr write workload you will see
anon_size increase. Eventually, if enough dirty data builds up
your system it will appear to hang. This occurs because the dmu
won't allow new txs to be assigned until that dirty data is
flushed, and it won't be because it's not part of an assigned tx.
As an aside, I typically see anon_size lurk around 16k so I think
there is another place in the code which needs a similar fix.
However, this value doesn't grow over time so it isn't critical.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #503
Issue #513
Brian Behlendorf [Mon, 27 Feb 2012 18:12:40 +0000 (10:12 -0800)]
Cleanly support debug packages
Allow a source rpm to be rebuilt with debugging enabled. This
avoids the need to have to manually modify the spec file. By
default debugging is still largely disabled. To enable specific
debugging features use the following options with rpmbuild.
'--with debug' - Enables ASSERTs
# For example:
$ rpmbuild --rebuild --with debug zfs-modules-0.6.0-rc6.src.rpm
Additionally, ZFS_CONFIG has been added to zfs_config.h for
packages which build against these headers. This is critical
to ensure both zfs and the dependant package are using the same
prototype and structure definitions.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Fri, 20 Jan 2012 18:58:57 +0000 (10:58 -0800)]
Add 'dmu_tx' kstats entry
Keep counters for the various reasons that a thread may end up
in txg_wait_open() waiting on a new txg. This can be useful
when attempting to determine why a particular workload is
under performing.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Mon, 30 Jan 2012 21:28:40 +0000 (13:28 -0800)]
Add arc_state_t stats to arcstats
To ensure the arc is behaving properly we need greater visibility
in to exactly how it's managing the systems memory. This patch
takes one step in that direction be adding the current arc_state_t
for the anon, mru, mru_ghost, mfu, and mfs_ghost lists. The l2
arc_state_t is already well represented in the arcstats.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ned Bass [Sat, 25 Feb 2012 00:37:41 +0000 (16:37 -0800)]
Return success from check_slice() if device doesn't exist
When creating a new pool, make_root_vdev() calls check_in_use() to
ensure that none of the consituent disks are in use. If the disk
contains a valid vdev label it is read to retrieve the list of its
child vdevs and these are checked recursively. However, the
partitions stored in the vdev label my no longer exist, for example
if the partition table has since been altered. In any such case we
would want the pool creation to proceed, so this change removes the
check from check_slice() that returns an error if the device doesn't
exist. As an added assurance, the Solaris implementation also
returns sucess on ENOENT.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Alex Zhuravlev [Fri, 17 Feb 2012 20:09:21 +0000 (12:09 -0800)]
Export symbols for zero-copy
Export additional symbols to make use of the DMU's zero-copy
API. This allows external modules to move data in to and out of
the ARC without incurring the cost of a memory copy.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Richard Yao [Mon, 13 Feb 2012 15:38:58 +0000 (10:38 -0500)]
Support ashift=13 for 8KB SSD block sizes
New SSDs are now available which use an internal 8k block size.
To make sure ZFS can get the maximum performance out of these
devices we're increasing the maximum ashift to 13 (8KB).
This value is still small enough that we can fit 16 uberblocks
in the vdev ring label. However, I don't want to increase this
any futher or it will limit the ability the safely roll back a
pool to recover it.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #565
Brian Behlendorf [Fri, 10 Feb 2012 19:53:09 +0000 (11:53 -0800)]
Export symbols for zero-copy
Exported the required symbols to make use of the DMU's zero-copy
API. This allows external modules to move data in to and out of
the ARC without incurring the cost of a memory copy.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Fri, 10 Feb 2012 00:33:55 +0000 (16:33 -0800)]
Use spl_debug_* helpers
When configuring the spl debug log support use the provided wrapper
functions. This ensures that if --disable-debug-log was used when
buiding the spl the functions will have no effect.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
DISCARD (REQ_DISCARD, BLKDISCARD) is useful for thin provisioning.
It allows ZVOL clients to discard (unmap, trim) block ranges from
a ZVOL, thus optimizing disk space usage by allowing a ZVOL to
shrink instead of just grow.
We can't use zfs_space() or zfs_freesp() here, since these functions
only work on regular files, not volumes. Fortunately we can use the
low-level function dmu_free_long_range() which does exactly what we
want.
Currently the discard operation is not added to the log. That's not
a big deal since losing discard requests cannot result in data
corruption. It would however result in disk space usage higher than
it should be. Thus adding log support to zvol_discard() is probably
a good idea for a future improvement.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is
supported, since it's the only one that matches the behavior of
zfs_space(). This makes it pretty much useless in its current
form, but it's a start.
To support other flag combinations we would need to modify
zfs_space() to make it more flexible, or emulate the desired
functionality in zpl_fallocate().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
This isn't done on Solaris because on this OS zfs_space() can
only be called with an opened file handle. Since the addition of
zpl_truncate_range() this isn't the case anymore, so we need to
enforce access rights.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
This operation allows "hole punching" in ZFS files. On Solaris this
is done via the vop_space() system call, which maps to the zfs_space()
function. So we just need to write zpl_truncate_range() as a wrapper
around zfs_space().
Note that this only works for regular files, not ZVOLs.
This is currently an insecure implementation without permission
checking, although this isn't that big of a deal since truncate_range()
isn't even callable from userspace.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #334
The recent zvol improvements have changed default suggested alignment
for zvols from 512b (default) to 8k (zvol blocksize). Because of this
the zconfig.sh tests which create paritions are now generating a
warning about non-optimal alignments.
This change updates the need zconfig.sh tests such that a partition
will be properly aligned. In the process, it shifts from using the
sfdisk utility to the parted utility to create partitions. It also
moves the creation of labels, partitions, and filesystems in to
generic functions in common.sh.in.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Currently, the `zvol_threads` variable, which controls the number of worker
threads which process items from the ZVOL queues, is set to the number of
available CPUs.
This choice seems to be based on the assumption that ZVOL threads are
CPU-bound. This is not necessarily true, especially for synchronous writes.
Consider the situation described in the comments for `zil_commit()`, which is
called inside `zvol_write()` for synchronous writes:
> itxs are committed in batches. In a heavily stressed zil there will be a
> commit writer thread who is writing out a bunch of itxs to the log for a
> set of committing threads (cthreads) in the same batch as the writer.
> Those cthreads are all waiting on the same cv for that batch.
>
> There will also be a different and growing batch of threads that are
> waiting to commit (qthreads). When the committing batch completes a
> transition occurs such that the cthreads exit and the qthreads become
> cthreads. One of the new cthreads becomes he writer thread for the batch.
> Any new threads arriving become new qthreads.
We can easily deduce that, in the case of ZVOLs, there can be a maximum of
`zvol_threads` cthreads and qthreads. The default value for `zvol_threads` is
typically between 1 and 8, which is way too low in this case. This means
there will be a lot of small commits to the ZIL, which is very inefficient
compared to a few big commits, especially since we have to wait for the data
to be on stable storage. Increasing the number of threads will increase the
amount of data waiting to be commited and thus the size of the individual
commits.
On my system, in the context of VM disk image storage (lots of small
synchronous writes), increasing `zvol_threads` from 8 to 32 results in a 50%
increase in sequential synchronous write performance.
We should choose a more sensible default for `zvol_threads`. Unfortunately
the optimal value is difficult to determine automatically, since it depends
on the synchronous write latency of the underlying storage devices. In any
case, a hardcoded value of 32 would probably be better than the current
situation. Having a lot of ZVOL threads doesn't seem to have any real
downside anyway.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fixes #392
The Linux block device queue subsystem exposes a number of configurable
settings described in Linux block/blk-settings.c. The defaults for these
settings are tuned for hard drives, and are not optimized for ZVOLs. Proper
configuration of these options would allow upper layers (I/O scheduler) to
take better decisions about write merging and ordering.
Detailed rationale:
- max_hw_sectors is set to unlimited (UINT_MAX). zvol_write() is able to
handle writes of any size, so there's no reason to impose a limit. Let the
upper layer decide.
- max_segments and max_segment_size are set to unlimited. zvol_write() will
copy the requests' contents into a dbuf anyway, so the number and size of
the segments are irrelevant. Let the upper layer decide.
- physical_block_size and io_opt are set to the ZVOL's block size. This
has the potential to somewhat alleviate issue #361 for ZVOLs, by warning
the upper layers that writes smaller than the volume's block size will be
slow.
- The NONROT flag is set to indicate this isn't a rotational device.
Although the backing zpool might be composed of rotational devices, the
resulting ZVOL often doesn't exhibit the same behavior due to the COW
mechanisms used by ZFS. Setting this flag will prevent upper layers from
making useless decisions (such as reordering writes) based on incorrect
assumptions about the behavior of the ZVOL.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
zvol_write() assumes that the write request must be written to stable storage
if rq_is_sync() is true. Unfortunately, this assumption is incorrect. Indeed,
"sync" does *not* mean what we think it means in the context of the Linux
block layer. This is well explained in linux/fs.h:
WRITE: A normal async write. Device will be plugged.
WRITE_SYNC: Synchronous write. Identical to WRITE, but passes down
the hint that someone will be waiting on this IO
shortly.
WRITE_FLUSH: Like WRITE_SYNC but with preceding cache flush.
WRITE_FUA: Like WRITE_SYNC but data is guaranteed to be on
non-volatile media on completion.
In other words, SYNC does not *mean* that the write must be on stable storage
on completion. It just means that someone is waiting on us to complete the
write request. Thus triggering a ZIL commit for each SYNC write request on a
ZVOL is unnecessary and harmful for performance. To make matters worse, ZVOL
users have no way to express that they actually want data to be written to
stable storage, which means the ZIL is broken for ZVOLs.
The request for stable storage is expressed by the FUA flag, so we must
commit the ZIL after the write if the FUA flag is set. In addition, we must
commit the ZIL before the write if the FLUSH flag is set.
Also, we must inform the block layer that we actually support FLUSH and FUA.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Darik Horn [Sun, 5 Feb 2012 02:54:43 +0000 (20:54 -0600)]
Let libnvpair be linked independently of libzfs.
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
Brian Behlendorf [Fri, 20 Jan 2012 23:02:57 +0000 (15:02 -0800)]
Cleanup ZFS debug infrastructure
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>
Brian Behlendorf [Fri, 27 Jan 2012 21:43:23 +0000 (13:43 -0800)]
Allow multiple values per directory entry
When using zfs to back a Lustre filesystem it's advantageous to
to store a fid with the object id in the directory zap. The only
technical impediment to doing this is that the zpl code expects
a single value in the zap per directory entry.
This change relaxes that requirement such that multiple entries
are allowed provided the first one is the object id. The zpl
code will just ignore additional entries. This allows the ZoL
count to mount datasets which are being used as Lustre server
backends.
Once the upstream feature flags support is merged in this change
should be updated to a read-only feature. Until this occurs
other zfs implementations will not be able to read the zfs
filesystems created by Lustre.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Prakash Surya [Wed, 18 Jan 2012 23:31:52 +0000 (15:31 -0800)]
Ignore dataset if the dds_type is DMU_OST_OTHER
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
Brian Behlendorf [Wed, 18 Jan 2012 00:20:43 +0000 (16:20 -0800)]
Fix rpm dependencies
This change updates the rpm spec files to have strictly correct
package dependencies. That means a few things:
* The zfs-modules package is now tied to a specific build of
the spl-modules packages based on the kernel version. This
ensures that the correct spl-modules packages will always get
installed and not just the newest.
* The zfs package now requires both the zfs-modules and spl
packages. Thus a 'yum install zfs' will pull in the minimal
set of packages required for a functional system.
* The zfs-devel packages now require the zfs package to be
installed which is normal behavior for -devel packages.
* Remove the redundant distribution release extension. This
is already added once because it is part of the kernel package
release name.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Brian Behlendorf [Wed, 18 Jan 2012 00:19:43 +0000 (16:19 -0800)]
Add the release component to headers
When the original build system code was added the release
component was accidentally omited from the development header
install path. This patch adds the missing path component so
it's always clear exactly what release your compiling against.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Darik Horn [Wed, 18 Jan 2012 18:28:11 +0000 (12:28 -0600)]
Allow GPT+EFI vdev replacement in boot pools.
Commit zfsonlinux/zfs@57a4eddc4d5e1e6c10d8d7dcf87a9fc27398adcd
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>
Darik Horn [Sat, 31 Dec 2011 23:30:52 +0000 (17:30 -0600)]
Combine libraries: spl, avl, efi, share, unicode.
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
Richard Laager [Fri, 13 Jan 2012 22:24:15 +0000 (16:24 -0600)]
Allow setting bootfs on any pool
The vdev_is_bootable() restrictions are no longer necessary
with recent GRUB2 code. FreeBSD has implemented the same
change, except that I moved the Solaris comment to be inside
the #ifdef __sun__ block.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #317
Ned Bass [Fri, 13 Jan 2012 21:51:39 +0000 (13:51 -0800)]
Reduce number of zio free threads
As described in Issue #458 and #258, unlinking large amounts of data
can cause the threads in the zio free wait queue to start spinning.
Reducing the number of z_fr_iss threads from a fixed value of 100 to 1
per cpu signficantly reduces contention on the taskq spinlock and
improves throughput.
Instrumenting the taskq code showed that __taskq_dispatch() can spend
a long time holding tq->tq_lock if there are a large number of threads
in the queue. It turns out the time spent in wake_up() scales
linearly with the number of threads in the queue. When a large number
of short work items are dispatched, as seems to be the case with
unlink, the worker threads drain the queue faster than the dispatcher
can fill it. They then all pile into the work wait queue to wait for
new work items. So if 100 threads are in the queue, wake_up() takes
about 100 times as long, and the woken threads have to spin until the
dispatcher releases the lock.
Reducing the number of threads helps with the symptoms, but doesn't
get to the root of the problem. It would seem that wake_up()
shouldn't scale linearly in time with queue depth, particularly if we
are only trying to wake up one thread. In that vein, I tried making
all of the waiting processes exclusive to prevent the scheduler from
iterating over the entire list, but I still saw the linear time
scaling. So further investigation is needed, but in the meantime
reducing the thread count is an easy workaround.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #258
Issue #458
Brian Behlendorf [Fri, 13 Jan 2012 19:35:05 +0000 (11:35 -0800)]
Increase link count limit to 2^31-1
Originally, the per-file link limit was set to 65536 because the
exact Linux VFS limit was unclear. Internally ZFS is able to
support 64-bit link counts. After a more careful investigation
the limit can be safely raised to 2^31-1.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #514
Prakash Surya [Fri, 13 Jan 2012 01:24:05 +0000 (17:24 -0800)]
Run ZFS_AC_PACMAN only if $VENDOR is "arch"
Unfortunately, Arch's package manager `pacman` shares it's name with a
popular arcade video game. Thus, in order to refrain from executing the
video game when we mean to execute the package manager, ZFS_AC_PACMAN is
now only run when $VENDOR is determined to be "arch".
Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #517
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
Brian Behlendorf [Thu, 12 Jan 2012 21:59:44 +0000 (13:59 -0800)]
Linux 3.2 compat, security_inode_init_security()
The security_inode_init_security() API has been changed to include
a filesystem specific callback to write security extended attributes.
This was done to support the initialization of multiple LSM xattrs
and the EVM xattr.
This change updates the code to use the new API when it's available.
Otherwise it falls back to the previous implementation.
In addition, the ZFS_AC_KERNEL_6ARGS_SECURITY_INODE_INIT_SECURITY
autoconf test has been made more rigerous by passing the expected
types. This is done to ensure we always properly the detect the
correct form for the security_inode_init_security() API.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #516
Brian Behlendorf [Thu, 22 Dec 2011 20:20:43 +0000 (12:20 -0800)]
Linux 3.1 compat, super_block->s_shrink
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.
* 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 #466
Closes #292
Prakash Surya [Sat, 17 Dec 2011 06:32:54 +0000 (22:32 -0800)]
Move Arch Linux's VENDOR check above Ubuntu's
If the lsb-release package is installed on an Arch Linux distribution,
the configure step will incorrectly detect the running distribution as
Ubuntu. This is a result of both distributions providing an
/etc/lsb-release file, and the Ubuntu VENDOR check being performed
first.
Since the Arch Linux test check's for a file more specific to the Arch
Linux distribution, moving Arch Linux's VENDOR check above Unbuntu's
check provides a quick and easy solution.
Signed-off-by: Prakash Surya <surya1@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Prakash Surya [Thu, 8 Dec 2011 01:02:42 +0000 (17:02 -0800)]
Add make rule for building Arch Linux packages
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
Garrett D'Amore [Tue, 8 Nov 2011 00:26:52 +0000 (16:26 -0800)]
Illumos #734: Use taskq_dispatch_ent() interface
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
The zvol_major and zvol_threads module options were being created
with 0 permission bits. This prevented them from being listed in
the /sys/module/zfs/parameters/ directory, although they were
visible in `modinfo zfs`. This patch fixes the issue by updating
the permission bits to 0444. For the moment these options must
be read-only because they are used during module initialization.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #392
In the upstream OpenSolaris ZFS code the maximum ARC usage is
limited to 3/4 of memory or all but 1GB, whichever is larger.
Because of how Linux's VM subsystem is organized these defaults
have proven to be too large which can lead to stability issues.
To avoid making everyone manually tune the ARC the defaults are
being changed to 1/2 of memory or all but 4GB. The rational for
this is as follows:
* Desktop Systems (less than 8GB of memory)
Limiting the ARC to 1/2 of memory is desirable for desktop
systems which have highly dynamic memory requirements. For
example, launching your web browser can suddenly result in a
demand for several gigabytes of memory. This memory must be
reclaimed from the ARC cache which can take some time. The
user will experience this reclaim time as a sluggish system
with poor interactive performance. Thus in this case it is
preferable to leave the memory as free and available for
immediate use.
* Server Systems (more than 8GB of memory)
Using all but 4GB of memory for the ARC is preferable for
server systems. These systems often run with minimal user
interaction and have long running daemons with relatively
stable memory demands. These systems will benefit most by
having as much data cached in memory as possible.
These values should work well for most configurations. However,
if you have a desktop system with more than 8GB of memory you may
wish to further restrict the ARC. This can still be accomplished
by setting the 'zfs_arc_max' module option.
Additionally, keep in mind these aren't currently hard limits.
The ARC is based on a slab implementation which can suffer from
memory fragmentation. Because this fragmentation is not visible
from the ARC it may believe it is within the specified limits while
actually consuming slightly more memory. How much more memory get's
consumed will be determined by how badly fragmented the slabs are.
In the long term this can be mitigated by slab defragmentation code
which was OpenSolaris solution. Or preferably, using the page cache
to back the ARC under Linux would be even better. See issue #75
for the benefits of more tightly integrating with the page cache.
This change also fixes a issue where the default ARC max was being
set incorrectly for machines with less than 2GB of memory. The
constant in the arc_c_max comparison must be explicitly cast to
a uint64_t type to prevent overflow and the wrong conditional
branch being taken. This failure was typically observed in VMs
which are commonly created with less than 2GB of memory.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #75
Darik Horn [Sun, 4 Dec 2011 21:32:18 +0000 (15:32 -0600)]
Quote variables in the zfs.lsb script.
For consistency and safety, quote all variables in the zfs.lsb script.
This protects in the unlikely case that any of the file names contain
whitespace.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #439
projects / mirror_zfs-debian.git / log