Commit Graph

386 Commits

Author SHA1 Message Date
Brian Behlendorf fea77534f0 Fix spl_config.h install permissions
The default permissions used by install are 755.  Since this
file isn't executable 644 is more appropriate.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-03-01 16:55:06 -08:00
Eric Dillmann 3cbfd259b7 Define BE_IN16 & BE_IN32 for lz4 compression
The new lz4 compression algorithm, zfsonlinux/zfs@9759c60, requires
the generic BE_IN16 and BE_IN32 functions.  These are added to the SPL
for other consumers to take advantage of.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-29 09:30:23 -08:00
Brian Behlendorf 0936c3449f Add spl_kmem_cache_expire module option
Cache aging was implemented because it was part of the default Solaris
kmem_cache behavior.  The idea is that per-cpu objects which haven't been
accessed in several seconds should be returned to the cache.  On the other
hand Linux slabs never move objects back to the slabs unless there is
memory pressure on the system.

This behavior is now configurable through the 'spl_kmem_cache_expire'
module option.  The value is a bit mask with the following meaning.

  0x1 - Solaris style cache aging eviction is enabled.
  0x2 - Linux style low memory eviction is enabled.

Both methods may be safely enabled simultaneously, but by default
both are disabled.  It has never been clear if the kmem cache aging
(which has been around from day one) actually does any good.  It has
however been the source of numerous bugs so I wouldn't mind retiring
it entirely.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#1227
Closes #210
2013-01-28 09:34:12 -08:00
Brian Behlendorf 84dd1f4f15 Remove spl_invalidate_inodes()
This functionality is no longer required by ZFS, see commit
zfsonlinux/zfs@7b3e34ba5a.
Since there are no other consumers, and because it adds
additional autoconf complexity which must be maintained
the spl_invalidate_inodes() function has been removed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#795
2013-01-17 11:40:47 -08:00
Brian Behlendorf 1c7b3eaf87 RHEL 6.4 compat, fallocate()
In the upstream kernel the FALLOC_FL_PUNCH_HOLE #define was
introduced after the fallocate() function was moved from the
inode_operations to the file_operations structure.  Therefore,
the SPL code assumed that if FALLOC_FL_PUNCH_HOLE was defined
it was safe to use f_ops->fallocate().

Unfortunately, the RHEL6.4 kernel has only backported the
FALLOC_FL_PUNCH_HOLE #define and not the fallocate() change.

To address this compatibility issue the spl_filp_fallocate()
helper function was added to properly detect which interface
is available.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-08 09:53:13 -08:00
Matt Johnston 46a75aadb7 Add cv_wait_io() to account I/O time
Under Linux when a task is waiting on I/O it should call the
io_schedule() function for proper accounting.  The Solaris
cv_wait() function provides no way to specify what the cv
is waiting on therefore cv_wait_io() is introduced.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #206
2013-01-07 10:29:26 -08:00
Brian Behlendorf 034f1b331e Fix spl_kmem_init_kallsyms_lookup() panic
Due to I/O buffering the helper may return successfully before
the proc handler has a chance to execute.  To catch this case
wait up to 1 second to verify spl_kallsyms_lookup_name_fn was
updated to a non SYMBOL_POISON value.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#699
Closes zfsonlinux/zfs#859
2012-12-19 09:06:35 -08:00
Brian Behlendorf eb0be2ed46 Removed SPL_AC_3ARGS_INIT_WORK check
All consumers of the kernel delayed work queues have been shifted
over to rely on the taskq implementation.  This compatibility code
can now be removed.  Any new callers which need this functionality
should use the taskq interfaces for delayed work items.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:57:10 -08:00
Brian Behlendorf 33e94ef1dd kmem-cache: Use a taskq for async allocations
Shift the asynchronous allocations over to use the taskq interfaces.
This allows us to abandon the kernels delayed work queue interface
and all the compatibility code it requires.

This code never actually used the delay functionality it was just
done this way to leverage the existing compatibility code.  All that
is required is a thread context to perform the allocation in.  The
only thing clever in this change is that we take advantage of the
preallocated task queue entries to avoid a memory allocation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:56:54 -08:00
Brian Behlendorf a10287e00d kmem-cache: Use taskqs for ageing
Shift the cache and magazine ageing functionality over to the new
delayed taskq interfaces.  This allows us to abandon the kernels
delayed work queue interface and all the compatibility code it
requires.

However, the delayed taskq interface does not allow us to schedule
a task for a specfic cpu so the ageing code was slightly reworked.
The magazine ageing delay has been directly linked to the cache
ageing function.  The spl_cache_age() function invokes on_each_cpu()
in order to run spl_magazine_age() on each cpu.  It then blocks
waiting for them to complete and promptly reclaims any free slabs.

When restructing the code wasn't the primary goal I think the
new code is far more understable and maintainable.  It also should
help minimize magazine thrashing because free slabs are immediately
released after the magazine is aged.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:56:54 -08:00
Brian Behlendorf d9acd930b5 taskq delay/cancel functionality
Add the ability to dispatch a delayed task to a taskq.  The desired
behavior is for the task to be queued but not executed by a worker
thread until the expiration time is reached.  To achieve this two
new functions were added.

* taskq_dispatch_delay() -

  This function behaves exactly like taskq_dispatch() however it
takes a third 'expire_time' argument.  The caller should pass the
desired time the task should be executed as an absolute value in
jiffies.  The task is guarenteed not to run before this time, it
may run slightly latter if all the worker threads are busy.

* taskq_cancel_id() -

  Given a task id attempt to cancel the task before it gets executed.
This is primarily useful for canceling delay tasks but can be used for
canceling any previously dispatched task.  There are three possible
return values.

  0      - The task was found and canceled before it was executed.
  ENOENT - The task was not found, either it was already run or an
           invalid task id was supplied by the caller.
  EBUSY  - The task is currently executing any may not be canceled.
           This function will block until the task has been completed.

* taskq_wait_all() -

  The taskq_wait_id() function was renamed taskq_wait_all() to more
clearly reflect its actual behavior.  It is only curreny used by
the splat taskq regression tests.

* taskq_wait_id() -

  Historically, the only difference between this function and
taskq_wait() was that you passed the task id.  In both functions you
would block until ALL lower task ids which executed.  This was
semantically correct but could be very slow particularly if there
were delay tasks submitted.

  To better accomidate the delay tasks this function was reimplemnted.
It will now only block until the passed task id has been completed.

This is actually a fairly low risk change for a few reasons.

* Only new ZFS callers will make use of the new interfaces and
  very little common code was changed to support the new functions.

* The existing taskq_wait() implementation was not changed just
  slightly refactored.

* The newly optimized taskq_wait_id() implementation was never
  used by ZFS we can't accidentally introduce a new bug there.

NOTE: This functionality does not exist in the Illumos taskqs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf aed8671cb0 taskq style, remove #define wrappers
When the taskq implementation was originally written I wrapped all
the API functions in #define's.  This was done as a preventative
measure to ensure that a taskq symbol never conflicted with an
existing kernel symbol.

However, in practice the taskq symbols never conflicted.  The only
major conflicts occured with the kmem cache API.  Since this added
layer of obfuscation never bought us anything for the taskq's I'm
removing it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf 472a34caff taskq style, convert spaces to soft tabs
Update the taskq implementation to conform with the style used
throughout the rest of the code.  There are no functional
changes in this commit.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-12-12 09:54:07 -08:00
Brian Behlendorf ed3163484d Track emergency object in rbtree
In the initial implementation emergency objects were tracked on a
per-cache list.  The assumption was that under normal operation we
would never allocate more than a handful of these objects.  So the
cost of walking the list during free was expected to be negligible.

However real world usage has shown that emergency objects tend to
be allocated in batches.  A deadlock will be detected and several
thousand emergency objects will be allocated before the original
blocked slab allocation can complete.

Therefore the original list has been replaced by a red black tree
which is sorted by the memory address of each allocated object.
This bounds the worst case insertion and removal time to O(log n)
which minimize contention on the assoicated spin lock.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:54:19 -08:00
Brian Behlendorf 165f13c33a Improved vmem cached deadlock detection
The entire goal of performing the slab allocations asynchronously
is to be able to detect when a vmalloc() deadlocks.  In this case,
and only this case, do we want to start allocating emergency objects.
The trick here is to minimize false positives because the overhead
of tracking emergency objects is far higher than normal slab objects.

With that goal in mind the code was reworked to be less sensitive
to slow allocations by increasing the wait time.  Once a cache is
is marked deadlocked all subsequent allocations which can not be
satisfied with existing cache objects will immediately allocate new
emergency objects.  This behavior persists until the asynchronous
allocation completes and clears the deadlocked flag.

The result of these tweaks is that far fewer emergency objects
get created which is important because this minimizes the cost of
releasing them latter in kmem_cache_free().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:54:15 -08:00
Brian Behlendorf df870a697f splat: Cleanup headers
Restructure the the SPLAT headers such that each test only
includes the minimal set of headers it requires.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:48:56 -08:00
Brian Behlendorf d2733258d0 Condition variable reference counts
Reference count every entry and exit from the condition variable
functions: cv_wait(), cv_wait_timeout(), cv_signal(), cv_broadcast().

This allows us to safely block in cv_destroy() until all consumers
have been scheduled and are no longer accessing the condition
variable memory.

In addition poison the magic value at the start of cv_destroy() to
ensure there are never any new callers after cv_destroy() is called.
The consumer is responsible for ensuring this never occurs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-06 14:48:55 -08:00
Brian Behlendorf dba79fcbf2 Add KSTAT_TYPE_TXG type
Add a new kstat type for tracking useful statistics about a TXG.
The new KSTAT_TYPE_TXG type can be used to tracks the following
statistics per-txg.

  txg          - Unique txg number
  state        - State (O)pen/(Q)uiescing/(S)yncing/(C)ommitted
  birth;       - Creation time
  nread        - Bytes read
  nwritten;    - Bytes written
  reads        - IOPs read
  writes       - IOPs write
  open_time;   - Length in nanoseconds the txg was open
  quiesce_time - Length in nanoseconds the txg was quiescing
  sync_time;   - Length in nanoseconds the txg was syncing

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-11-02 15:17:40 -07:00
Brian Behlendorf 71c9f0b003 Make kstat.ks_update() callback atomic
Move the kstat ks_update() callback under the ks_lock.  This
enables dynamically sized kstats without modification to the
kstat API.

  * Create a kstat with the KSTAT_FLAG_VIRTUAL flag.
  * Register a ->ks_update() callback which does:
    o Frees any existing ks_data buffer.
    o Set ks_data_size to the kstat array size.
    o Set ks_data to an allocated buffer of size ks_data_size
    o Populate the array of buffers with the required data.

The buffer allocated in the ks_update() callback is guaranteed
to remain allocated and valid while the proc sequence handler
iterates over the buffer.  The lock will not be dropped until
kstat_seq_stop() function is run making it safe for concurrent
access.  To allow the ks_update() callback to perform memory
allocations the lock was changed to a mutex.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-10-23 09:36:19 -07:00
Brian Behlendorf 1e0c2c2ccf Linux 3.7 compat, __clear_close_on_exec() removed
Commit torvalds/linux@b8318b0 moved the __clear_close_on_exec()
function out of include/linux/fdtable.h and in to fs/file.c
making it unavailable to the SPL.

Now as it turns out we only used this function to tear down
some test infrastructure for the vn_getf()/vn_releasef() SPLAT
regression tests.  Rather than implement even more autoconf
compatibilty code to handle this we just remove the test case.
This also allows us to drop three existing autoconf tests.

This does mean the SPLAT tests will no longer verify these
functions but historically they have never been a problem.
And if we feel we absolutely need this test coverage I'm
sure a more portable version of the test case could be added.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #183
2012-10-18 13:36:44 -07:00
Yuxuan Shui bcb15891ab Linux 3.6 compat, kern_path_locked() added
The kern_path_parent() function was removed from Linux 3.6 because
it was observed that all the callers just want the parent dentry.
The simpler kern_path_locked() function replaces kern_path_parent()
and does the lookup while holding the ->i_mutex lock.

This is good news for the vn implementation because it removes the
need for us to handle the locking.  However, it makes it harder to
implement a single readable vn_remove()/vn_rename() function which
is usually what we prefer.

Therefore, we implement a new version of vn_remove()/vn_rename()
for Linux 3.6 and newer kernels.  This allows us to leave the
existing working implementation untouched, and to add a simpler
version for newer kernels.

Long term I would very much like to see all of the vn code removed
since what this code enabled is generally frowned upon in the kernel.
But that can't happen util we either abondon the zpool.cache file
or implement alternate infrastructure to update is correctly in
user space.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #154
2012-10-14 16:26:21 -07:00
Etienne Dechamps bbdc6ae495 Add interface for file hole punching.
This adds an interface to "punch holes" (deallocate space) in VFS
files. The interface is identical to the Solaris VOP_SPACE interface.
This interface is necessary for TRIM support on file vdevs.

This is implemented using Linux fallocate(FALLOC_FL_PUNCH_HOLE), which
was introduced in 2.6.38. For a brief time before 2.6.38 this was done
using the truncate_range inode operation, which was quickly deprecated.
This patch only supports FALLOC_FL_PUNCH_HOLE.

This adds support for the truncate_range() inode operation to
VOP_SPACE() for file hole punching. This API is deprecated and removed
in 3.5, so it's only useful for old kernels.

On tmpfs, the truncate_range() inode operation translates to
shmem_truncate_range(). Unfortunately, this function expects the end
offset to be inclusive and aligned to the end of a page. If it is not,
the kernel will stop with a BUG_ON().

This patch fixes the issue by adapting to the constraints set forth by
shmem_truncate_range().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #168
2012-10-04 16:22:07 -07:00
Brian Behlendorf 9b51f21841 Remove TQ_SLEEP -> KM_SLEEP mapping
When the taskq code was originally written it seemed like a good
idea to simply map TQ_SLEEP to KM_SLEEP.  Unfortunately, this
assumed that the TQ_* flags would never confict with any of the
Linux GFP_* flags.  When adding the TQ_PUSHPAGE support in commit
cd5ca4b this invariant was accidentally broken.

Therefore to support TQ_PUSHPAGE, which is needed for Linux, and
prevent any further confusion I have removed this direct mapping.
The TQ_SLEEP, TQ_NOSLEEP, and TQ_PUSHPAGE are no longer defined
in terms of their KM_* counterparts.  Instead a simple mapping
function is introduce to convert TQ_* -> KM_* where needed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #171
2012-09-12 11:41:42 -07:00
Brian Behlendorf 330fe010e4 Revert "Switch KM_SLEEP to KM_PUSHPAGE"
This reverts commit cd5ca4b2f8
due to conflicts in the higher TQ_ bits which caused incorrect
behavior.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-09-12 10:07:48 -07:00
Brian Behlendorf cb5c2acebb Add KMC_NOEMERGENCY slab flag
Provide a flag to disable the use of emergency objects for a
specific kmem cache.  There may be instances where under no
circumstances should you kmalloc() an emergency object.  For
example, when you cache contains very large objects (>128k).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-09-07 14:27:03 -07:00
Etienne Dechamps ac8ca67a88 Add DKIOCTRIM for TRIM support.
See dechamps/zfs@cc6cd40ad7 for details.

This harmless addition was merged to simplify testing the ZFS TRIM
support patches.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #167
2012-09-02 14:22:01 -07:00
Brian Behlendorf cd5ca4b2f8 Switch KM_SLEEP to KM_PUSHPAGE
Under certain circumstances the following functions may be called
in a context where KM_SLEEP is unsafe and can result in a deadlocked
system.  To avoid this problem the unconditional KM_SLEEPs are
converted to KM_PUSHPAGEs.  This will prevent them from attempting
to initiate any I/O during direct reclaim.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:55 -07:00
Brian Behlendorf 3e904f40b4 Mutex ASSERT on self deadlock
Generate an assertion if we're going to deadlock the system by
attempting to acquire a mutex the process is already holding.

There are currently no known instances of this under normal
operation, but it _might_ be possible when using a ZVOL as a
swap device.  I want to ensure we catch this immediately if it
were to occur.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:55 -07:00
Brian Behlendorf eb0f407a2b Add PF_NOFS debugging flag
PF_NOFS is a per-process debug flag which is set in current->flags to
detect when a process is performing an unsafe allocation.  All tasks
with PF_NOFS set must strictly use KM_PUSHPAGE for allocations because
if they enter direct reclaim and initiate I/O they may deadlock.

When debugging is disabled, any incorrect usage will be detected and
a call stack with a warning will be printed to the console.  The flags
will then be automatically corrected to allow for safe execution.  If
debugging is enabled this will be treated as a fatal condition.

To avoid any risk of conflicting with the existing PF_ flags.  The
PF_NOFS bit shadows the rarely used PF_MUTEX_TESTER bit.  Only when
CONFIG_RT_MUTEX_TESTER is not set, and we know this bit is unused,
will the PF_NOFS bit be valid.  Happily, most existing distributions
ship a kernel with CONFIG_RT_MUTEX_TESTER disabled.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:55 -07:00
Brian Behlendorf d47e664ad4 Revert "Add TASKQ_NORECLAIM flag"
This reverts commit 372c257233.  The
use of the PF_MEMALLOC flag was always a hack to work around memory
reclaim deadlocks.  Those issues are believed to be resolved so this
workaround can be safely reverted.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:42 -07:00
Brian Behlendorf e2dcc6e2b8 Emergency slab objects
This patch is designed to resolve a deadlock which can occur with
__vmalloc() based slabs.  The issue is that the Linux kernel does
not honor the flags passed to __vmalloc().  This makes it unsafe
to use in a writeback context.  Unfortunately, this is a use case
ZFS depends on for correct operation.

Fixing this issue in the upstream kernel was pursued and patches
are available which resolve the issue.

  https://bugs.gentoo.org/show_bug.cgi?id=416685

However, these changes were rejected because upstream felt that
using __vmalloc() in the context of writeback should never be done.
Their solution was for us to rewrite parts of ZFS to accomidate
the Linux VM.

While that is probably the right long term solution, and it is
something we want to pursue, it is not a trivial task and will
likely destabilize the existing code.  This work has been planned
for the 0.7.0 release but in the meanwhile we want to improve the
SPL slab implementation to accomidate this expected ZFS usage.

This is accomplished by performing the __vmalloc() asynchronously
in the context of a work queue.  This doesn't prevent the posibility
of the worker thread from deadlocking.  However, the caller can now
safely block on a wait queue for the slab allocation to complete.

Normally this will occur in a reasonable amount of time and the
caller will be woken up when the new slab is available,.  The objects
will then get cached in the per-cpu magazines and everything will
proceed as usual.

However, if the __vmalloc() deadlocks for the reasons described
above, or is just very slow, then the callers on the wait queues
will timeout out.  When this rare situation occurs they will attempt
to kmalloc() a single minimally sized object using the GFP_NOIO flags.
This allocation will not deadlock because kmalloc() will honor the
passed flags and the caller will be able to make forward progress.

As long as forward progress can be maintained then even if the
worker thread is deadlocked the critical thread will make progress.
This will eventually allow the deadlocked worker thread to complete
and normal operation will resume.

These emergency allocations will likely be slow since they require
contiguous pages.  However, their use should be rare so the impact
is expected to be minimal.  If that turns out not to be the case in
practice further optimizations are possible.

One additional concern is if these emergency objects are long lived.
Right now they are simply tracked on a list which must be walked when
an object is freed.  Is they accumulate on a system and the list
grows freeing objects will become more expensive.  This could be
handled relatively easily by using a hash instead of a list, but that
optimization (if needed) is left for a follow up patch.

Additionally, these emeregency objects could be repacked in to existing
slabs as objects are freed if the kmem_cache_set_move() functionality
was implemented.  See issue https://github.com/zfsonlinux/spl/issues/26
for full details.  This work would also help reduce ZFS's memory
fragmentation problems.

The /proc/spl/kmem/slab file has had two new columns added at the
end.  The 'emerg' column reports the current number of these emergency
objects in use for the cache, and the following 'max' column shows
the historical worst case.  These value should give us a good idea
of how often these objects are needed.  Based on these values under
real use cases we can tune the default behavior.

Lastly, as a side benefit using a single work queue for the slab
allocations should reduce cpu contention on the global virtual address
space lock.   This should manifest itself as reduced cpu usage for
the system.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-08-27 12:00:42 -07:00
Brian Behlendorf c638e9ad04 Remove autotools products
Remove all of the generated autotools products from the repository
and update the .gitignore files accordingly.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#718
2012-08-27 11:46:23 -07:00
Prakash Surya 45324c7c41 Add kpreempt_[dis|en]able macros in <sys/disp.h>
To support preempt enabled kernels in ZFS on Linux, there are a couple
places where the ZFS code needs to disable interrupts. This change adds
the Solaris preempt functions and maps them to the equivalent ZFS
functions, allowing the ZFS to make use of them.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #98
2012-08-24 15:18:38 -07:00
Prakash Surya 08850eddcb Avoid calling smp_processor_id in spl_magazine_age
The spl_magazine_age function had the implied assumption that it will
remain on its current cpu through its execution. In order to support
preempt enabled kernels, this assumption had to be removed.

The spl_kmem_magazine structure now holds the cpu id of the cpu it is
local to. This allows spl_magazine_age to use this field when scheduling
work to be done by the magazine's local cpu.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #98
2012-08-24 09:43:22 -07:00
Richard Yao 15d0411297 Remove Makefile from non-toplevel .gitignore files
When building SPL support into the kernel, ./copy-builtin will copy
non-toplevel .gitignore files. These files list /Makefile, which causes
git-archive to omit ./module/{spl,splat}/Makefile. The absence of these
files result in build failures when SPL is selected. ZFS is unaffected
because it puts Makefile in the toplevel .gitignore, which is not
copied. We fix SPL by emulating that behavior.

Reported-by: Fabio Erculiani <lxnay@gentoo.org>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #152
2012-08-23 12:49:04 -07:00
Richard Yao 6576a1a70d Fix incorrect type in spl_kmem_cache_set_move() parameter
A preprocessor definition renders this harmless. However, it is a good
idea to change this to be consistent.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
2012-08-01 16:35:18 -07:00
Brian Behlendorf d503b971f4 Optimize spl_rwsem_is_locked()
The spl_rwsem_is_locked() compatibility function has been observed
to be a hot spot.  The root cause of this is that we must check the
rwsem activity under the rwsem->wait_lock to avoid a race.  When
the lock is busy significant contention can occur.

The upstream kernel fix for this race had the insight that by using
spin_trylock_irqsave() this contention could be avoided.  When the
lock is contended it's reasonable to return that it is locked.

This change updates the SPLs implemention to be like the upstream
kernel.  Since the kernel code has been in use for years now this
a low risk change.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-07-13 13:07:39 -07:00
Richard Yao 973e8269bd Constify memory management functions
This prevents warnings in ZFS that were caused by changes necessary to
support PaX patched kernels. When debugging is enabled, these warnings
become build failures.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #131
2012-07-03 16:07:27 -07:00
Brian Behlendorf 44e406d712 PowerPC Compatibility
Usage of get_current() is not supported across all architectures.
The correct interface to use is the '#define current' which will
map to the appropriate function, usually current_thread_info().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #119
2012-07-02 09:33:09 -07:00
Richard Yao e0093fea58 Linux 3.4 compat, __clear_close_on_exec replaces FD_CLR
torvalds/linux@1dce27c5aa introduced
__clear_close_on_exec() as a replacement for FD_CLR. Further commits
appear to have removed FD_CLR from the Linux source tree.  This
causes the following failure:

  error: implicit declaration of function '__FD_CLR'
  [-Werror=implicit-function-declaration]

To correct this we update the code to use the current
__clear_close_on_exec() interface for readability.  Then we introduce
an autotools check to determine if __clear_close_on_exec() is available.
If it isn't then we define some compatibility logic which used the older
FD_CLR() interface.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #124
2012-06-13 16:18:51 -07:00
Brian Behlendorf 38d31a1e57 Remove Solaris module emulation
Originally I believed that these interfaces would be needed.
However, in practice it turned out that it was more straight
forward and maintainable to use the native Linux interfaces.
As such, this is all dead code and can be safely removed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #109
2012-05-18 13:57:44 -07:00
Richard Yao f90096c905 Modify KM_PUSHPAGE to use GFP_NOIO instead of GFP_NOFS
The resolution of issue #31 made KM_PUSHPAGE imply GFP_NOFS.  This
was done to prevent situations where filesystem operations which are
holding locks enter direct reclaim and attempt to reaquire those
same locks.  This clearly will result in a deadlock.

This works for datasets which are implemented in terms for filesystem
operations.  But unfortunately, swapping to a zvol will encounter
many of the same deadlocks and GFP_NOFS will not prevent this.  As
such, it is appropriate to extend KM_PUSHPAGE to use the broader
GFP_NOIO mask to handle these non-filesystem cases.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue zfsonlinux/zfs#342
Closes #105
2012-05-07 12:05:27 -07:00
Prakash Surya cef7605c34 Throttle number of freed slabs based on nr_to_scan
Previously, the SPL tried to maintain Solaris semantics by freeing
all available (empty) slabs from its slab caches when the shrinker
was called. This is not desirable when running on Linux. To make
the SPL shrinker more Linux friendly, the actual number of freed
slabs from each of the slab caches is now derived from nr_to_scan
and skc_slab_objs.

Additionally, an accounting bug was fixed in spl_slab_reclaim()
which could cause us to reclaim one more slab than requested.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #101
2012-05-07 11:46:15 -07:00
Jorgen Lundman cb75844e85 Define the needed ISA types for ARM
Add the minimum required ISA types to support the ARM architecture.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-05-03 09:56:15 -07:00
Brian Behlendorf b29012b999 Remove condition variable names
Long ago I added support to the spl for condition variable names
because I thought they might be needed.  It turns out they aren't.
In fact the official Solaris cv_init(9F) man page discourages
their use in the kernel.

  cv_init(9F)
    Parameters
      name - Descriptive string. This is obsolete and should be
             NULL. (Non-NULL strings are legal, but they're a
             waste of kernel memory.)

Therefore, I'm removing them from the spl to reclaim this memory
and adding an ASSERT() to ensure no new consumers are added which
make use of the name.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-04-06 12:06:19 -07:00
Brian Behlendorf 0835057ee7 Add SPL_META_RELEASE to module load/unload messages
Include the ZFS_META_RELEASE in the module load/unload messages
to more clearly indicate exactly what version of the SPL has
been loaded.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-03-23 12:11:50 -07:00
Brian Behlendorf 3c208a5480 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
  '--with debug-log'           - Enables the internal debug log
  '--with debug-kmem'          - Enables basic memory accounting
  '--with debug-kmem-tracking' - Enables detailed memory tracking

  # For example:
  $ rpmbuild --rebuild --with debug spl-modules-0.6.0-rc6.src.rpm

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-02-27 14:24:22 -08:00
Brian Behlendorf feedc43601 Add missing spl_debug_* helpers
When building the spl with --disable-debug-log the __SDEBUG()
macro and spl_debug_* helper functions were undefined.  This
change adds the missing functions so the upper layers compiling
against the spl don't need to be aware of how the spl was built.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-02-09 16:41:46 -08:00
Brian Behlendorf 9a8b7a7458 Add basic dynamic kstat support
Add the bare minimum functionality to support dynamic kstats.  A
complete kstat implementation should be done as part of issue #84.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #84
2012-02-02 11:28:00 -08:00
Brian Behlendorf 4b2220f0b9 Add --enable-debug-log configure option
Until now the notion of an internal debug logging infrastructure
was conflated with enabling ASSERT()s.  This patch clarifies things
by cleanly breaking the two subsystem apart.  The result of this
is the following behavior.

--enable-debug      - Enable/disable code wrapped in ASSERT()s.
--disable-debug       ASSERT()s are used to check invariants and
                      are never required for correct operation.
                      They are disabled by default because they
                      may impact performance.

--enable-debug-log  - Enable/disable the debug log infrastructure.
--disable-debug-log   This infrastructure allows the spl code and
                      its consumer to log messages to an in-kernel
                      log.  The granularity of the logging can be
                      controlled by a debug mask.  By default the
                      mask disables most debug messages resulting
                      in a negligible performance impact.  Because
                      of this the debug log is enabled by default.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2012-02-02 11:27:54 -08:00