Commit Graph

26 Commits

Author SHA1 Message Date
Ryan Moeller 36a6e2335c
Don't ignore zfs_arc_max below allmem/32
Set arc_c_min before arc_c_max so that when zfs_arc_min is set lower
than the default allmem/32 zfs_arc_max can also be set lower.

Add warning messages when tunables are being ignored.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10157
Closes #10158
2020-04-09 15:39:48 -07:00
Ryan Moeller 7e3df9db12
Finish refactoring for ZFS_MODULE_PARAM_CALL
Linux and FreeBSD have different parameters for tunable proc handler.
This has prevented FreeBSD from implementing the ZFS_MODULE_PARAM_CALL
macro.

To complete the sharing of ZFS_MODULE_PARAM_CALL declarations, create
per-platform definitions of the parameter list, ZFS_MODULE_PARAM_ARGS.

With the declarations wired up we discovered an incorrect scope prefix
for spa_slop_shift, so this is now fixed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10179
2020-04-07 10:06:22 -07:00
Matthew Ahrens 1dc32a67e9
Improve zfs send performance by bypassing the ARC
When doing a zfs send on a dataset with small recordsize (e.g. 8K),
performance is dominated by the per-block overheads.  This is especially
true with `zfs send --compressed`, which further reduces the amount of
data sent, for the same number of blocks.  Several threads are involved,
but the limiting factor is the `send_prefetch` thread, which is 100% on
CPU.

The main job of the `send_prefetch` thread is to issue zio's for the
data that will be needed by the main thread.  It does this by calling
`arc_read(ARC_FLAG_PREFETCH)`.  This has an immediate cost of creating
an arc_hdr, which takes around 14% of one CPU.  It also induces later
costs by other threads:

 * Since the data was only prefetched, dmu_send()->dmu_dump_write() will
   need to call arc_read() again to get the data.  This will have to
   look up the arc_hdr in the hash table and copy the data from the
   scatter ABD in the arc_hdr to a linear ABD in arc_buf.  This takes
   27% of one CPU.

 * dmu_dump_write() needs to arc_buf_destroy()  This takes 11% of one
   CPU.

 * arc_adjust() will need to evict this arc_hdr, taking about 50% of one
   CPU.

All of these costs can be avoided by bypassing the ARC if the data is
not already cached.  This commit changes `zfs send` to check for the
data in the ARC, and if it is not found then we directly call
`zio_read()`, reading the data into a linear ABD which is used by
dmu_dump_write() directly.

The performance improvement is best expressed in terms of how many
blocks can be processed by `zfs send` in one second.  This change
increases the metric by 50%, from ~100,000 to ~150,000.  When the amount
of data per block is small (e.g. 2KB), there is a corresponding
reduction in the elapsed time of `zfs send >/dev/null` (from 86 minutes
to 58 minutes in this test case).

In addition to improving the performance of `zfs send`, this change
makes `zfs send` not pollute the ARC cache.  In most cases the data will
not be reused, so this allows us to keep caching useful data in the MRU
(hit-once) part of the ARC.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10067
2020-03-10 10:51:04 -07:00
loli10K e35704647e Fix for ARC sysctls ignored at runtime
This change leverage module_param_call() to run arc_tuning_update()
immediately after the ARC tunable has been updated as suggested in
cffa8372 code review.

A simple test case is added to the ZFS Test Suite to prevent future
regressions in functionality.

Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #9487  
Closes #9489
2019-10-26 15:22:19 -07:00
Matthew Macy c9c9c1e213 OpenZFS restructuring - ARC memory pressure
Factor Linux specific memory pressure handling out of ARC.  Each
platform will have different available interfaces for managing memory
pressure.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9472
2019-10-18 13:23:19 -04:00
Matthew Macy 13a4027a7c OpenZFS restructuring - arc_stats
Make arc_stats visible to platform code.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9386
2019-10-01 16:35:05 -07:00
Andrea Gelmini cf7c5a030e Fix typos in include/
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #9238
2019-08-30 09:53:15 -07:00
Tim Schumacher c13060e478 Linux 4.19-rc3+ compat: Remove refcount_t compat
torvalds/linux@59b57717f ("blkcg: delay blkg destruction until
after writeback has finished") added a refcount_t to the blkcg
structure. Due to the refcount_t compatibility code, zfs_refcount_t
was used by mistake.

Resolve this by removing the compatibility code and replacing the
occurrences of refcount_t with zfs_refcount_t.

Reviewed-by: Franz Pletz <fpletz@fnordicwalking.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes #7885 
Closes #7932
2018-09-26 10:29:26 -07:00
Tom Caputi be9a5c355c Add support for decryption faults in zinject
This patch adds the ability for zinject to trigger decryption
and authentication faults in the ZIO and ARC layers. This
functionality is exposed via the new "decrypt" error type, which
may be provided for "data" object types.

This patch also refactors some of the core encryption / decryption
functions so that they have consistent prototypes, handle errors
consistently, and do not have unused arguments.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7474
2018-05-02 15:36:20 -07:00
Tom Caputi a8b2e30685 Support re-prioritizing asynchronous prefetches
When sequential scrubs were merged, all calls to arc_read()
(including prefetch IOs) were given ZIO_PRIORITY_ASYNC_READ.
Unfortunately, this behaves badly with an existing issue where
prefetch IOs cannot be re-prioritized after the issue. The
result is that synchronous reads end up in the same vdev_queue
as the scrub IOs and can have (in some workloads) multiple
seconds of latency.

This patch incorporates 2 changes. The first ensures that all
scrub IOs are given ZIO_PRIORITY_SCRUB to allow the vdev_queue
code to differentiate between these I/Os and user prefetches.
Second, this patch introduces zio_change_priority() to provide
the missing capability to upgrade a zio's priority.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #6921 
Closes #6926
2017-12-21 09:13:06 -08:00
Tom Caputi 440a3eb939 Fixes for #6639
Several issues were uncovered by running stress tests with zfs
encryption and raw sends in particular. The issues and their
associated fixes are as follows:

* arc_read_done() has the ability to chain several requests for
  the same block of data via the arc_callback_t struct. In these
  cases, the ARC would only use the first request's dsobj from
  the bookmark to decrypt the data. This is problematic because
  the first request might be a prefetch zio which is able to
  handle the key not being loaded, while the second might use a
  different key that it is sure will work. The fix here is to
  pass the dsobj with each individual arc_callback_t so that each
  request can attempt to decrypt the data separately.

* DRR_FREE and DRR_FREEOBJECT records in a send file were not
  having their transactions properly tagged as raw during raw
  sends, which caused a panic when the dbuf code attempted to
  decrypt these blocks.

* traverse_prefetch_metadata() did not properly set
  ZIO_FLAG_SPECULATIVE when issuing prefetch IOs.

* Added a few asserts and code cleanups to ensure these issues
  are more detectable in the future.

Signed-off-by: Tom Caputi <tcaputi@datto.com>
2017-10-11 16:55:50 -04:00
Tom Caputi b525630342 Native Encryption for ZFS on Linux
This change incorporates three major pieces:

The first change is a keystore that manages wrapping
and encryption keys for encrypted datasets. These
commands mostly involve manipulating the new
DSL Crypto Key ZAP Objects that live in the MOS. Each
encrypted dataset has its own DSL Crypto Key that is
protected with a user's key. This level of indirection
allows users to change their keys without re-encrypting
their entire datasets. The change implements the new
subcommands "zfs load-key", "zfs unload-key" and
"zfs change-key" which allow the user to manage their
encryption keys and settings. In addition, several new
flags and properties have been added to allow dataset
creation and to make mounting and unmounting more
convenient.

The second piece of this patch provides the ability to
encrypt, decyrpt, and authenticate protected datasets.
Each object set maintains a Merkel tree of Message
Authentication Codes that protect the lower layers,
similarly to how checksums are maintained. This part
impacts the zio layer, which handles the actual
encryption and generation of MACs, as well as the ARC
and DMU, which need to be able to handle encrypted
buffers and protected data.

The last addition is the ability to do raw, encrypted
sends and receives. The idea here is to send raw
encrypted and compressed data and receive it exactly
as is on a backup system. This means that the dataset
on the receiving system is protected using the same
user key that is in use on the sending side. By doing
so, datasets can be efficiently backed up to an
untrusted system without fear of data being
compromised.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #494 
Closes #5769
2017-08-14 10:36:48 -07:00
Matthew Ahrens 64fc776208 OpenZFS 7968 - multi-threaded spa_sync()
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Matthew Ahrens <mahrens@delphix.com>

spa_sync() iterates over all the dirty dnodes and processes each of them
by calling dnode_sync(). If there are many dirty dnodes (e.g. because we
created or removed a lot of files), the single thread of spa_sync()
calling dnode_sync() can become a bottleneck. Additionally, if many
dnodes are dirtied concurrently in open context (e.g. due to concurrent
file creation), the os_lock will experience lock contention via
dnode_setdirty().

The solution is to track dirty dnodes on a multilist_t, and for
spa_sync() to use separate threads to process each of the sublists in
the multilist.

OpenZFS-issue: https://www.illumos.org/issues/7968
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/4a2a54c
Closes #5752
2017-03-20 18:36:00 -07:00
ka7 4e33ba4c38 Fix spelling
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Haakan T Johansson <f96hajo@chalmers.se>
Closes #5547 
Closes #5543
2017-01-03 11:31:18 -06:00
David Quigley a6255b7fce DLPX-44812 integrate EP-220 large memory scalability 2016-11-29 14:34:27 -08:00
Dan Kimmel 2aa34383b9 DLPX-40252 integrate EP-476 compressed zfs send/receive
Authored by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: David Quigley <david.quigley@intel.com>
Issue #5078
2016-09-13 09:58:58 -07:00
George Wilson d3c2ae1c08 OpenZFS 6950 - ARC should cache compressed data
Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: David Quigley <david.quigley@intel.com>

This review covers the reading and writing of compressed arc headers, sharing
data between the arc_hdr_t and the arc_buf_t, and the implementation of a new
dbuf cache to keep frequently access data uncompressed.

I've added a new member to l1 arc hdr called b_pdata. The b_pdata always hangs
off the arc_buf_hdr_t (if an L1 hdr is in use) and points to the physical block
for that DVA. The physical block may or may not be compressed. If compressed
arc is enabled and the block on-disk is compressed, then the b_pdata will match
the block on-disk and remain compressed in memory. If the block on disk is not
compressed, then neither will the b_pdata. Lastly, if compressed arc is
disabled, then b_pdata will always be an uncompressed version of the on-disk
block.

Typically the arc will cache only the arc_buf_hdr_t and will aggressively evict
any arc_buf_t's that are no longer referenced. This means that the arc will
primarily have compressed blocks as the arc_buf_t's are considered overhead and
are always uncompressed. When a consumer reads a block we first look to see if
the arc_buf_hdr_t is cached. If the hdr is cached then we allocate a new
arc_buf_t and decompress the b_pdata contents into the arc_buf_t's b_data. If
the hdr already has a arc_buf_t, then we will allocate an additional arc_buf_t
and bcopy the uncompressed contents from the first arc_buf_t to the new one.

Writing to the compressed arc requires that we first discard the b_pdata since
the physical block is about to be rewritten. The new data contents will be
passed in via an arc_buf_t (uncompressed) and during the I/O pipeline stages we
will copy the physical block contents to a newly allocated b_pdata.

When an l2arc is inuse it will also take advantage of the b_pdata. Now the
l2arc will always write the contents of b_pdata to the l2arc. This means that
when compressed arc is enabled that the l2arc blocks are identical to those
stored in the main data pool. This provides a significant advantage since we
can leverage the bp's checksum when reading from the l2arc to determine if the
contents are valid. If the compressed arc is disabled, then we must first
transform the read block to look like the physical block in the main data pool
before comparing the checksum and determining it's valid.

OpenZFS-issue: https://www.illumos.org/issues/6950
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7fc10f0
Issue #5078
2016-09-13 09:58:33 -07:00
Paul Dagnelie bc77ba73fe OpenZFS 6513 - partially filled holes lose birth time
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Boris Protopopov <bprotopopov@hotmail.com>
Approved by: Richard Lowe <richlowe@richlowe.net>a
Ported by: Boris Protopopov <bprotopopov@actifio.com>
Signed-off-by: Boris Protopopov <bprotopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6513
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/8df0bcf0

If a ZFS object contains a hole at level one, and then a data block is
created at level 0 underneath that l1 block, l0 holes will be created.
However, these l0 holes do not have the birth time property set; as a
result, incremental sends will not send those holes.

Fix is to modify the dbuf_read code to fill in birth time data.
2016-06-21 10:55:13 -07:00
Arne Jansen 4e0f33ffe0 Illumos 6214 - zpools going south
6214 zpools going south
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>

References:
  https://www.illumos.org/issues/6214
  http://cr.illumos.org/~webrev/sensille/6214_zpools_going_south/

Porting Notes:

Reintroduce b_compress to the l2arc_buf_hdr_t.  In commit b9541d6
the compression flags were moved to the generic b_flags in the
arc_buf_hdr_t.  This is a problem because l2arc_compress_buf()
may manipulate the compression flags and this can only be done
safely under the hash lock which is not held.  See Illumos 6214
for a detailed analysis of the race.

HDR_GET_COMPRESS() macro was removed from arc_buf_info().

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3757
2015-09-11 11:14:38 -07:00
Prakash Surya 36da08ef9b Illumos 5817 - change type of arcs_size from uint64_t to refcount_t
5817 change type of arcs_size from uint64_t to refcount_t
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/5817
  https://github.com/illumos/illumos-gate/commit/2fd872a

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
2015-07-23 09:42:28 -07:00
Prakash Surya d962d5dad9 Illumos 5701 - zpool list reports incorrect "alloc" value for cache devices
5701 zpool list reports incorrect "alloc" value for cache devices
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Alek Pinchuk <alek.pinchuk@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5701
  https://github.com/illumos/illumos-gate/commit/a52fc31

Porting Notes:

arc_space_return(HDR_L2ONLY_SIZE, ARC_SPACE_L2HDRS);
correctly placed at arc_hdr_l2hdr_destroy(arc_buf_hdr_t *hdr).

Ported by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-06-25 08:51:44 -07:00
Prakash Surya ca0bf58d65 Illumos 5497 - lock contention on arcs_mtx
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>

Porting notes and other significant code changes:

The illumos 5368 patch (ARC should cache more metadata), which
was never picked up by ZoL, is mostly reverted by this patch.

Since ZoL relies on the kernel asynchronously calling the shrinker to
actually reap memory, the shrinker wakes up arc_reclaim_waiters_cv every
time it runs.

The arc_adapt_thread() function no longer calls arc_do_user_evicts()
since the newly-added arc_user_evicts_thread() calls it periodically.

Notable conflicting ZoL commits which conflicted with this patch or
whose effects are either duplicated or un-done by this patch:

    302f753 - Integrate ARC more tightly with Linux
    39e055c - Adjust arc_p based on "bytes" in arc_shrink
    f521ce1 - Allow "arc_p" to drop to zero or grow to "arc_c"
    77765b5 - Remove "arc_meta_used" from arc_adjust calculation
    94520ca - Prune metadata from ghost lists in arc_adjust_meta

Trace support for multilist_insert() and multilist_remove() has been
added and produces the following output:

    fio-12498 [077] .... 112936.448324: zfs_multilist__insert: ml { offset 240 numsublists 80 sublistidx 63 }
    fio-12498 [077] .... 112936.448347: zfs_multilist__remove: ml { offset 240 numsublists 80 sublistidx 29 }

The following arcstats have been removed:

    recycle_miss - Used by arcstat.py and arc_summary.py, both of which
    have been updated appropriately.

    l2_writes_hdr_miss

The following arcstats have been added:

    evict_not_enough - Number of times arc_evict_state() was unable to
    evict enough buffers to reach its target amount.

    evict_l2_skip - Number of times arc_evict_hdr() skipped eviction
    because it was being written to the l2arc.

    l2_writes_lock_retry - Replaces l2_writes_hdr_miss.  Number of times
    l2arc_write_done() failed to acquire hash_lock (and re-tries).

    arc_meta_min - Shows the value of the zfs_arc_meta_min module
    parameter (see below).

The "index" column of the "dbuf" kstat has been removed since it doesn't
have a direct analog in the new multilist scheme.  Additional multilist-
related stats could be added in the future but would likely require
extensions to the mulilist API.

The following module parameters have been added:

    zfs_arc_evict_batch_limit - Number of ARC headers to free per sub-list
    before moving on to the next sub-list.

    zfs_arc_meta_min - Enforce a floor on the amount of metadata in
    the ARC.

    zfs_arc_num_sublists_per_state - Number of multilist sub-lists per
    ARC state.

    zfs_arc_overflow_shift - Controls amount by which the ARC must exceed
    the target size to be considered "overflowing".

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov
2015-06-11 10:27:25 -07:00
Chris Williamson b9541d6b7d Illumos 5408 - managing ZFS cache devices requires lots of RAM
5408 managing ZFS cache devices requires lots of RAM
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Don Brady <dev.fs.zfs@gmail.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>

Porting notes:

Due to the restructuring of the ARC-related structures, this
patch conflicts with at least the following existing ZoL commits:

    6e1d7276c9
    Fix inaccurate arcstat_l2_hdr_size calculations

        The ARC_SPACE_HDRS constant no longer exists and has been
        somewhat equivalently replaced by HDR_L2ONLY_SIZE.

    e0b0ca983d
    Add visibility in to cached dbufs

        The new layering of l{1,2}arc_buf_hdr_t within the arc_buf_hdr
        struct requires additional structure member names to be used
        when referencing the inner items.  Also, the presence of L1 or L2
        inner member is indicated by flags using the new HDR_HAS_L{1,2}HDR
        macros.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-06-11 10:27:25 -07:00
George Wilson 2a4324141f Illumos 5369 - arc flags should be an enum
5369 arc flags should be an enum
5370 consistent arc_buf_hdr_t naming scheme
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

Porting notes:

ZoL has moved some ARC definitions into arc_impl.h.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: Tim Chase <tim@chase2k.com>
2015-06-11 10:27:25 -07:00
Ned Bass 49ee64e5e6 Remove duplicate typedefs from trace.h
Older versions of GCC (e.g. GCC 4.4.7 on RHEL6) do not allow duplicate
typedef declarations with the same type. The trace.h header contains
some typedefs to avoid 'unknown type' errors for C files that haven't
declared the type in question. But this causes build failures for C
files that have already declared the type. Newer versions of GCC (e.g.
v4.6) allow duplicate typedefs with the same type unless pedantic error
checking is in force. To support the older versions we need to remove
the duplicate typedefs.

Removal of the typedefs means we can't built tracepoints code using
those types unless the required headers have been included. To
facilitate this, all tracepoint event declarations have been moved out
of trace.h into separate headers. Each new header is explicitly included
from the C file that uses the events defined therein. The trace.h header
is still indirectly included form zfs_context.h and provides the
implementation of the dprintf(), dbgmsg(), and SET_ERROR() interfaces.
This makes those interfaces readily available throughout the code base.
The macros that redefine DTRACE_PROBE* to use Linux tracepoints are also
still provided by trace.h, so it is a prerequisite for the other
trace_*.h headers.

These new Linux implementation-specific headers do introduce a small
divergence from upstream ZFS in several core C files, but this should
not present a significant maintenance burden.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2953
2015-01-06 16:53:24 -08:00
Ned Bass 59ec819a0c Move a few internal ARC strucutres to arc_impl.h
Add a new file named arc_impl.h and move a few internal
ARC structure definitions into this file. This is
needed in order to allow the Linux tracepoint functions to grub
around in the internals of these structures.

Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2014-11-17 11:13:27 -08:00