Commit Graph

184 Commits

Author SHA1 Message Date
Olaf Faaland
cec3a0a1bb Report pool suspended due to MMP
When the pool is suspended, record whether it was due to an I/O error or
due to MMP writes failing to succeed within the required time.

Change spa_suspended from uint8_t to zio_suspend_reason_t to store the
reason.

When userspace queries pool status via spa_tryimport(), report the
reason the pool was suspended in a new key,
ZPOOL_CONFIG_SUSPENDED_REASON.

In libzfs, when interpreting the returned config nvlist, report
suspension due to MMP with a new pool status enum value,
ZPOOL_STATUS_IO_FAILURE_MMP.

In status_callback(), which generates and emits the message when 'zpool
status' is executed, add a case to print an appropriate message for the
new pool status enum value.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #7296
2018-03-15 10:56:55 -07:00
Tom Caputi
b1d217338a Raw receives must compress metadnode blocks
Currently, the DMU relies on ZIO layer compression to free LO
dnode blocks that no longer have objects in them. However,
raw receives disable all compression, meaning that these blocks
can never be freed. In addition to the obvious space concerns,
this could also cause incremental raw receives to fail to mount
since the MAC of a hole is different from that of a completely
zeroed block.

This patch corrects this issue by adding a special case in
zio_write_compress() which will attempt to compress these blocks
to a hole even if ZIO_FLAG_RAW_ENCRYPT is set. This patch also
removes the zfs_mdcomp_disable tunable, since tuning it could
cause these same issues.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7198
2018-02-21 12:28:52 -08:00
George Wilson
ddc751d56b OpenZFS 8857 - zio_remove_child() panic due to already destroyed parent zio
PROBLEM
=======
It's possible for a parent zio to complete even though it has children
which have not completed. This can result in the following panic:
    > $C
    ffffff01809128c0 vpanic()
    ffffff01809128e0 mutex_panic+0x58(fffffffffb94c904, ffffff597dde7f80)
    ffffff0180912950 mutex_vector_enter+0x347(ffffff597dde7f80)
    ffffff01809129b0 zio_remove_child+0x50(ffffff597dde7c58, ffffff32bd901ac0,
    ffffff3373370908)
    ffffff0180912a40 zio_done+0x390(ffffff32bd901ac0)
    ffffff0180912a70 zio_execute+0x78(ffffff32bd901ac0)
    ffffff0180912b30 taskq_thread+0x2d0(ffffff33bae44140)
    ffffff0180912b40 thread_start+8()
    > ::status
    debugging crash dump vmcore.2 (64-bit) from batfs0390
    operating system: 5.11 joyent_20170911T171900Z (i86pc)
    image uuid: (not set)
    panic message: mutex_enter: bad mutex, lp=ffffff597dde7f80
    owner=ffffff3c59b39480 thread=ffffff0180912c40
    dump content: kernel pages only
The problem is that dbuf_prefetch along with l2arc can create a zio tree
which confuses the parent zio and allows it to complete with while children
still exist. Here's the scenario:
    zio tree:
        pio
         |--- lio
The parent zio, pio, has entered the zio_done stage and begins to check its
children to see there are still some that have not completed. In zio_done(),
the children are checked in the following order:
    zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)
    zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)
    zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)
    zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)
If pio, finds any child which has not completed then it stops executing and
goes to sleep. Each call to zio_wait_for_children() will grab the io_lock
while checking the particular child.
In this scenario, the pio has completed the first call to
zio_wait_for_children() to check for any ZIO_CHILD_VDEV children. Since
the only zio in the zio tree right now is the logical zio, lio, then it
completes that call and prepares to check the next child type.
In the meantime, the lio completes and in its callback creates a child vdev
zio, cio. The zio tree looks like this:
    zio tree:
        pio
         |--- lio
         |--- cio
The lio then grabs the parent's io_lock and removes itself.
    zio tree:
        pio
         |--- cio
The pio continues to run but has already completed its check for ZIO_CHILD_VDEV
and will erroneously complete. When the child zio, cio, completes it will panic
the system trying to reference the parent zio which has been destroyed.
SOLUTION
========
The fix is to rework the zio_wait_for_children() logic to accept a bitfield
for all the children types that it's interested in checking. The
io_lock will is held the entire time we check all the children types. Since
the function now accepts a bitfield, a simple ZIO_CHILD_BIT() macro is provided
to allow for the conversion between a ZIO_CHILD type and the bitfield used by
the zio_wiat_for_children logic.

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Youzhong Yang <youzhong@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/8857
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/862ff6d99c
Issue #5918
Closes #7168
2018-02-14 15:30:09 -08:00
Tom Caputi
ae76f45cda Encryption Stability and On-Disk Format Fixes
The on-disk format for encrypted datasets protects not only
the encrypted and authenticated blocks themselves, but also
the order and interpretation of these blocks. In order to
make this work while maintaining the ability to do raw
sends, the indirect bps maintain a secure checksum of all
the MACs in the block below it along with a few other
fields that determine how the data is interpreted.

Unfortunately, the current on-disk format erroneously
includes some fields which are not portable and thus cannot
support raw sends. It is not possible to easily work around
this issue due to a separate and much smaller bug which
causes indirect blocks for encrypted dnodes to not be
compressed, which conflicts with the previous bug. In
addition, the current code generates incompatible on-disk
formats on big endian and little endian systems due to an
issue with how block pointers are authenticated. Finally,
raw send streams do not currently include dn_maxblkid when
sending both the metadnode and normal dnodes which are
needed in order to ensure that we are correctly maintaining
the portable objset MAC.

This patch zero's out the offending fields when computing
the bp MAC and ensures that these MACs are always
calculated in little endian order (regardless of the host
system's byte order). This patch also registers an errata
for the old on-disk format, which we detect by adding a
"version" field to newly created DSL Crypto Keys. We allow
datasets without a version (version 0) to only be mounted
for read so that they can easily be migrated. We also now
include dn_maxblkid in raw send streams to ensure the MAC
can be maintained correctly.

This patch also contains minor bug fixes and cleanups.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #6845
Closes #6864
Closes #7052
2018-02-02 11:37:16 -08:00
Brian Behlendorf
8fb1ede146 Extend deadman logic
The intent of this patch is extend the existing deadman code
such that it's flexible enough to be used by both ztest and
on production systems.  The proposed changes include:

* Added a new `zfs_deadman_failmode` module option which is
  used to dynamically control the behavior of the deadman.  It's
  loosely modeled after, but independant from, the pool failmode
  property.  It can be set to wait, continue, or panic.

    * wait     - Wait for the "hung" I/O (default)
    * continue - Attempt to recover from a "hung" I/O
    * panic    - Panic the system

* Added a new `zfs_deadman_ziotime_ms` module option which is
  analogous to `zfs_deadman_synctime_ms` except instead of
  applying to a pool TXG sync it applies to zio_wait().  A
  default value of 300s is used to define a "hung" zio.

* The ztest deadman thread has been re-enabled by default,
  aligned with the upstream OpenZFS code, and then extended
  to terminate the process when it takes significantly longer
  to complete than expected.

* The -G option was added to ztest to print the internal debug
  log when a fatal error is encountered.  This same option was
  previously added to zdb in commit fa603f82.  Update zloop.sh
  to unconditionally pass -G to obtain additional debugging.

* The FM_EREPORT_ZFS_DELAY event which was previously posted
  when the deadman detect a "hung" pool has been replaced by
  a new dedicated FM_EREPORT_ZFS_DEADMAN event.

* The proposed recovery logic attempts to restart a "hung"
  zio by calling zio_interrupt() on any outstanding leaf zios.
  We may want to further restrict this to zios in either the
  ZIO_STAGE_VDEV_IO_START or ZIO_STAGE_VDEV_IO_DONE stages.
  Calling zio_interrupt() is expected to only be useful for
  cases when an IO has been submitted to the physical device
  but for some reasonable the completion callback hasn't been
  called by the lower layers.  This shouldn't be possible but
  has been observed and may be caused by kernel/driver bugs.

* The 'zfs_deadman_synctime_ms' default value was reduced from
  1000s to 600s.

* Depending on how ztest fails there may be no cache file to
  move.  This should not be considered fatal, collect the logs
  which are available and carry on.

* Add deadman test cases for spa_deadman() and zio_wait().

* Increase default zfs_deadman_checktime_ms to 60s.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6999
2018-01-25 13:40:38 -08:00
Prakash Surya
2fe61a7ecc OpenZFS 8909 - 8585 can cause a use-after-free kernel panic
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: John Kennedy <jwk404@gmail.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Prakash Surya <prakash.surya@delphix.com>

PROBLEM
=======

There's a race condition that exists if `zil_free_lwb` races with either
`zil_commit_waiter_timeout` and/or `zil_lwb_flush_vdevs_done`.

Here's an example panic due to this bug:

    > ::status
    debugging crash dump vmcore.0 (64-bit) from ip-10-110-205-40
    operating system: 5.11 dlpx-5.2.2.0_2017-12-04-17-28-32b6ba51fb (i86pc)
    image uuid: 4af0edfb-e58e-6ed8-cafc-d3e9167c7513
    panic message:
    BAD TRAP: type=e (#pf Page fault) rp=ffffff0010555970 addr=60 occurred in module "zfs" due to a NULL pointer dereference
    dump content: kernel pages only

    > $c
    zio_shrink+0x12()
    zil_lwb_write_issue+0x30d(ffffff03dcd15cc0, ffffff03e0730e20)
    zil_commit_waiter_timeout+0xa2(ffffff03dcd15cc0, ffffff03d97ffcf8)
    zil_commit_waiter+0xf3(ffffff03dcd15cc0, ffffff03d97ffcf8)
    zil_commit+0x80(ffffff03dcd15cc0, 9a9)
    zfs_write+0xc34(ffffff03dc38b140, ffffff0010555e60, 40, ffffff03e00fb758, 0)
    fop_write+0x5b(ffffff03dc38b140, ffffff0010555e60, 40, ffffff03e00fb758, 0)
    write+0x250(42, fffffd7ff4832000, 2000)
    sys_syscall+0x177()

If there's an outstanding lwb that's in `zil_commit_waiter_timeout`
waiting to timeout, waiting on it's waiter's CV, we must be sure not to
call `zil_free_lwb`. If we end up calling `zil_free_lwb`, then that LWB
may be freed and can result in a use-after-free situation where the
stale lwb pointer stored in the `zil_commit_waiter_t` structure of the
thread waiting on the waiter's CV is used.

A similar situation can occur if an lwb is issued to disk, and thus in
the `LWB_STATE_ISSUED` state, and `zil_free_lwb` is called while the
disk is servicing that lwb. In this situation, the lwb will be freed by
`zil_free_lwb`, which will result in a use-after-free situation when the
lwb's zio completes, and `zil_lwb_flush_vdevs_done` is called.

This race condition is prevented in `zil_close` by calling `zil_commit`
before `zil_free_lwb` is called, which will ensure all outstanding (i.e.
all lwb's in the `LWB_STATE_OPEN` and/or `LWB_STATE_ISSUED` states)
reach the `LWB_STATE_DONE` state before the lwb's are freed
(`zil_commit` will not return untill all the lwb's are
`LWB_STATE_DONE`).

Further, this race condition is prevented in `zil_sync` by only calling
`zil_free_lwb` for lwb's that do not have their `lwb_buf` pointer set.
All lwb's not in the `LWB_STATE_DONE` state will have a non-null value
for this pointer; the pointer is only cleared in
`zil_lwb_flush_vdevs_done`, at which point the lwb's state will be
changed to `LWB_STATE_DONE`.

This race *is* present in `zil_suspend`, leading to this bug.

At first glance, it would appear as though this would not be true
because `zil_suspend` will call `zil_commit`, just like `zil_close`, but
the problem is that `zil_suspend` will set the zilog's `zl_suspend`
field prior to calling `zil_commit`. Further, in `zil_commit`, if
`zl_suspend` is set, `zil_commit` will take a special branch of logic
and use `txg_wait_synced` instead of performing the normal `zil_commit`
logic.

This call to `txg_wait_synced` might be good enough for the data to
reach disk safely before it returns, but it does not ensure that all
outstanding lwb's reach the `LWB_STATE_DONE` state before it returns.
This is because, if there's an lwb "stuck" in
`zil_commit_waiter_timeout`, waiting for it's lwb to timeout, it will
maintain a non-null value for it's `lwb_buf` field and thus `zil_sync`
will not free that lwb. Thus, even though the lwb's data is already on
disk, the lwb will be left lingering, waiting on the CV, and will
eventually timeout and be issued to disk even though the write is
unnecessary.

So, after `zil_commit` is called from `zil_suspend`, we incorrectly
assume that there are not outstanding lwb's, and proceed to free all
lwb's found on the zilog's lwb list. As a result, we free the lwb that
will later be used `zil_commit_waiter_timeout`.

SOLUTION
========

The solution to this, is to ensure all outstanding lwb's complete before
calling `zil_free_lwb` via `zil_destroy` in `zil_suspend`. This patch
accomplishes this goal by forcing the normal `zil_commit` logic when
called from `zil_sync`.

Now, `zil_suspend` will call `zil_commit_impl` which will always use the
normal logic of waiting/issuing lwb's to disk before it returns. As a
result, any lwb's outstanding when `zil_commit_impl` is called will be
guaranteed to reach the `LWB_STATE_DONE` state by the time it returns.

Further, no new lwb's will be created via `zil_commit` since the zilog's
`zl_suspend` flag will be set. This will force all new callers of
`zil_commit` to use `txg_wait_synced` instead of creating and issuing
new lwb's.

Thus, all lwb's left on the zilog's lwb list when `zil_destroy` is
called will be in the `LWB_STATE_DONE` state, and we'll avoid this race
condition.

OpenZFS-issue: https://www.illumos.org/issues/8909
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ece62b6f8d
Closes #6940
2017-12-28 10:18:04 -08:00
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
Prakash Surya
1ce23dcaff OpenZFS 8585 - improve batching done in zil_commit()
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Prakash Surya <prakash.surya@delphix.com>

Problem
=======

The current implementation of zil_commit() can introduce significant
latency, beyond what is inherent due to the latency of the underlying
storage. The additional latency comes from two main problems:

 1. When there's outstanding ZIL blocks being written (i.e. there's
    already a "writer thread" in progress), then any new calls to
    zil_commit() will block waiting for the currently oustanding ZIL
    blocks to complete. The blocks written for each "writer thread" is
    coined a "batch", and there can only ever be a single "batch" being
    written at a time. When a batch is being written, any new ZIL
    transactions will have to wait for the next batch to be written,
    which won't occur until the current batch finishes.

    As a result, the underlying storage may not be used as efficiently
    as possible. While "new" threads enter zil_commit() and are blocked
    waiting for the next batch, it's possible that the underlying
    storage isn't fully utilized by the current batch of ZIL blocks. In
    that case, it'd be better to allow these new threads to generate
    (and issue) a new ZIL block, such that it could be serviced by the
    underlying storage concurrently with the other ZIL blocks that are
    being serviced.

 2. Any call to zil_commit() must wait for all ZIL blocks in its "batch"
    to complete, prior to zil_commit() returning. The size of any given
    batch is proportional to the number of ZIL transaction in the queue
    at the time that the batch starts processing the queue; which
    doesn't occur until the previous batch completes. Thus, if there's a
    lot of transactions in the queue, the batch could be composed of
    many ZIL blocks, and each call to zil_commit() will have to wait for
    all of these writes to complete (even if the thread calling
    zil_commit() only cared about one of the transactions in the batch).

To further complicate the situation, these two issues result in the
following side effect:

 3. If a given batch takes longer to complete than normal, this results
    in larger batch sizes, which then take longer to complete and
    further drive up the latency of zil_commit(). This can occur for a
    number of reasons, including (but not limited to): transient changes
    in the workload, and storage latency irregularites.

Solution
========

The solution attempted by this change has the following goals:

 1. no on-disk changes; maintain current on-disk format.
 2. modify the "batch size" to be equal to the "ZIL block size".
 3. allow new batches to be generated and issued to disk, while there's
    already batches being serviced by the disk.
 4. allow zil_commit() to wait for as few ZIL blocks as possible.
 5. use as few ZIL blocks as possible, for the same amount of ZIL
    transactions, without introducing significant latency to any
    individual ZIL transaction. i.e. use fewer, but larger, ZIL blocks.

In theory, with these goals met, the new allgorithm will allow the
following improvements:

 1. new ZIL blocks can be generated and issued, while there's already
    oustanding ZIL blocks being serviced by the storage.
 2. the latency of zil_commit() should be proportional to the underlying
    storage latency, rather than the incoming synchronous workload.

Porting Notes
=============

Due to the changes made in commit 119a394ab0, the lifetime of an itx
structure differs than in OpenZFS. Specifically, the itx structure is
kept around until the data associated with the itx is considered to be
safe on disk; this is so that the itx's callback can be called after the
data is committed to stable storage. Since OpenZFS doesn't have this itx
callback mechanism, it's able to destroy the itx structure immediately
after the itx is committed to an lwb (before the lwb is written to
disk).

To support this difference, and to ensure the itx's callbacks can still
be called after the itx's data is on disk, a few changes had to be made:

  * A list of itxs was added to the lwb structure. This list contains
    all of the itxs that have been committed to the lwb, such that the
    callbacks for these itxs can be called from zil_lwb_flush_vdevs_done(),
    after the data for the itxs is committed to disk.

  * A list of itxs was added on the stack of the zil_process_commit_list()
    function; the "nolwb_itxs" list. In some circumstances, an itx may
    not be committed to an lwb (e.g. if allocating the "next" ZIL block
    on disk fails), so this list is used to keep track of which itxs
    fall into this state, such that their callbacks can be called after
    the ZIL's writer pipeline is "stalled".

  * The logic to actually call the itx's callback was moved into the
    zil_itx_destroy() function. Since all consumers of zil_itx_destroy()
    were effectively performing the same logic (i.e. if callback is
    non-null, call the callback), it seemed like useful code cleanup to
    consolidate this logic into a single function.

Additionally, the existing Linux tracepoint infrastructure dealing with
the ZIL's probes and structures had to be updated to reflect these code
changes. Specifically:

  * The "zil__cw1" and "zil__cw2" probes were removed, so they had to be
    removed from "trace_zil.h" as well.

  * Some of the zilog structure's fields were removed, which affected
    the tracepoint definitions of the structure.

  * New tracepoints had to be added for the following 3 new probes:
      * zil__process__commit__itx
      * zil__process__normal__itx
      * zil__commit__io__error

OpenZFS-issue: https://www.illumos.org/issues/8585
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/5d95a3a
Closes #6566
2017-12-05 09:39:16 -08:00
Tom Caputi
d4a72f2386 Sequential scrub and resilvers
Currently, scrubs and resilvers can take an extremely
long time to complete. This is largely due to the fact
that zfs scans process pools in logical order, as
determined by each block's bookmark. This makes sense
from a simplicity perspective, but blocks in zfs are
often scattered randomly across disks, particularly
due to zfs's copy-on-write mechanisms.

This patch improves performance by splitting scrubs
and resilvers into a metadata scanning phase and an IO
issuing phase. The metadata scan reads through the
structure of the pool and gathers an in-memory queue
of I/Os, sorted by size and offset on disk. The issuing
phase will then issue the scrub I/Os as sequentially as
possible, greatly improving performance.

This patch also updates and cleans up some of the scan
code which has not been updated in several years.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Authored-by: Alek Pinchuk <apinchuk@datto.com>
Authored-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #3625 
Closes #6256
2017-11-15 17:27:01 -08:00
Don Brady
1c27024e22 Undo c89 workarounds to match with upstream
With PR 5756 the zfs module now supports c99 and the
remaining past c89 workarounds can be undone.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #6816
2017-11-04 13:25:13 -07:00
Tom Caputi
4807c0badb Encryption patch follow-up
* PBKDF2 implementation changed to OpenSSL implementation.

* HKDF implementation moved to its own file and tests
  added to ensure correctness.

* Removed libzfs's now unnecessary dependency on libzpool
  and libicp.

* Ztest can now create and test encrypted datasets. This is
  currently disabled until issue #6526 is resolved, but
  otherwise functions as advertised.

* Several small bug fixes discovered after enabling ztest
  to run on encrypted datasets.

* Fixed coverity defects added by the encryption patch.

* Updated man pages for encrypted send / receive behavior.

* Fixed a bug where encrypted datasets could receive
  DRR_WRITE_EMBEDDED records.

* Minor code cleanups / consolidation.

Signed-off-by: Tom Caputi <tcaputi@datto.com>
2017-10-11 16:54:48 -04:00
Don Brady
d977122da9 Add corruption failure option to zinject(8)
Added a 'corrupt' error option that will flip a bit in the data
after a read operation.  This is useful for generating checksum
errors at the device layer (in a mirror config for example). It
is also used to validate the diagnosis of checksum errors from
the zfs diagnosis engine.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@intel.com>
Closes #6345
2017-08-14 15:17:15 -07:00
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
sanjeevbagewadi
21df134f4c zio_dva_throttle_done() should allow zinjected ZIO
If fault injection is enabled, the ZIO_FLAG_IO_RETRY could be set by
zio_handle_device_injection() to generate the FMA events and update
stats. Hence, ignore the flag and process such zios.

A better fix would be to add another flag in the zio_t to indicate that
the zio is failed because of a zinject rule. However, considering the
fact that we do this in debug bits, we could do with the crude check
using the global flag zio_injection_enabled which is set to 1 when
zinject records are added.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Sanjeev Bagewadi <sanjeev.bagewadi@gmail.com>
Closes #6383 
Closes #6384
2017-08-10 15:53:40 -07:00
Tony Hutter
6710381680 Only record zio->io_delay on reads and writes
While investigating https://github.com/zfsonlinux/zfs/issues/6425 I
noticed that ioctl ZIOs were not setting zio->io_delay correctly.  They
would set the start time in zio_vdev_io_start(), but never set the end
time in zio_vdev_io_done(), since ioctls skip it and go straight to
zio_done().  This was causing spurious "delayed IO" events to appear,
which would eventually get rate-limited and displayed as
"Missed events" messages in zed.

To get around the problem, this patch only sets zio->io_delay for read
and write ZIOs, since that's all we care about anyway.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #6425 
Closes #6440
2017-08-02 09:08:38 -07:00
Olaf Faaland
f43615d0cc Revert Fix vdev_probe() call wrt SCL_STATE_ALL
This reverts commit cc9c6bc, which has been causing intermittent
test failures on buildbot.  A correct fix for this locking issue
has been applied in a separate patch.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-07-25 12:24:42 -04:00
Brian Behlendorf
cc9c6bcb73 Fix vdev_probe() call outside SCL_STATE_ALL lock
When an IO fails then zio_vdev_io_done() can call vdev_probe()
to determine the health of the vdev.  This is safe as long as
the original zio was submitted with zio_wait() and holds the
SCL_STATE_ALL lock over the operation.

If zio_no_wait() was used then the done callback will submit
the probe IO outside the SCL_STATE_ALL lock and hit this
ASSERT in zio_create()

  ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));

Resolve the issue by only allowing vdev_probe() to be called
when there's a waiter indicating the caller is using zio_wait().
This assumes that caller is still holding SCL_STATE_ALL.

This issue isn't MMP specific but was surfaced when testing.
Without this patch it can be reproduced by running:

  zpool set multihost on <pool>
  zinject -d <vdev> -e io -T write -f 50 <pool> -L uber

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@intel.com>
Closes #745
Closes #6279
2017-07-13 13:54:10 -04:00
Giuseppe Di Natale
1b7c1e5ce9 OpenZFS 7578 - Fix/improve some aspects of ZIL writing
- After some ZIL changes 6 years ago zil_slog_limit got partially broken
due to zl_itx_list_sz not updated when async itx'es upgraded to sync.
Actually because of other changes about that time zl_itx_list_sz is not
really required to implement the functionality, so this patch removes
some unneeded broken code and variables.

 - Original idea of zil_slog_limit was to reduce chance of SLOG abuse by
single heavy logger, that increased latency for other (more latency critical)
loggers, by pushing heavy log out into the main pool instead of SLOG.  Beside
huge latency increase for heavy writers, this implementation caused double
write of all data, since the log records were explicitly prepared for SLOG.
Since we now have I/O scheduler, I've found it can be much more efficient
to reduce priority of heavy logger SLOG writes from ZIO_PRIORITY_SYNC_WRITE
to ZIO_PRIORITY_ASYNC_WRITE, while still leave them on SLOG.

 - Existing ZIL implementation had problem with space efficiency when it
has to write large chunks of data into log blocks of limited size.  In some
cases efficiency stopped to almost as low as 50%.  In case of ZIL stored on
spinning rust, that also reduced log write speed in half, since head had to
uselessly fly over allocated but not written areas.  This change improves
the situation by offloading problematic operations from z*_log_write() to
zil_lwb_commit(), which knows real situation of log blocks allocation and
can split large requests into pieces much more efficiently.  Also as side
effect it removes one of two data copy operations done by ZIL code WR_COPIED
case.

 - While there, untangle and unify code of z*_log_write() functions.
Also zfs_log_write() alike to zvol_log_write() can now handle writes crossing
block boundary, that may also improve efficiency if ZPL is made to do that.

Sponsored by:   iXsystems, Inc.

Authored by: Alexander Motin <mav@FreeBSD.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Steven Hartland <steven.hartland@multiplay.co.uk>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/7578
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/aeb13ac
Closes #6191
2017-06-09 09:15:37 -07:00
jxiong
24fa20340d Guarantee PAGESIZE alignment for large zio buffers
In current implementation, only zio buffers in 16KB and bigger are
guaranteed PAGESIZE alignment. This breaks Lustre since it assumes
that 'arc_buf_t::b_data' must be page aligned when zio buffers are
greater than or equal to PAGESIZE.

This patch will make the zio buffers to be PAGESIZE aligned when
the sizes are not less than PAGESIZE.

This change may cause a little bit memory waste but that should be
fine because after ABD is introduced, zio buffers are used to hold
data temporarily and live in memory for a short while.

Reviewed-by: Don Brady <don.brady@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jinshan Xiong <jinshan.xiong@gmail.com>
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Closes #6084
2017-05-02 10:04:30 -07:00
Gvozden Neskovic
84c07adadb Remove dependency on linear ABD
Wherever possible it's best to avoid depending on a linear ABD.
Update the code accordingly in the following areas.

- vdev_raidz
- zio, zio_checksum
- zfs_fm
- change abd_alloc_for_io() to use abd_alloc()

Reviewed-by: David Quigley <david.quigley@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #5668
2017-03-29 12:24:51 -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
Daniel Hoffman
9e2c3bb4b9 OpenZFS 7812 - Remove gender specific language
Authored by: Daniel Hoffman <dj.hoffman@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Steve Gonczi <steve.gonczi@delphix.com>
Reviewed by: Chris Williamson <chris.williamson@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

This change removes all gendered language that did not refer specifically
to an individual person or pet. The convention taken was to use
variations on "they" when referring to users and/or human beings, while
using "it" when referring to code, functions, and/or libraries.
Additionally, we took the liberty to fix up any whitespace issues that
were found in any files that were already being modified.

OpenZFS-issue: https://www.illumos.org/issues/7812
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ad626db
Closes #5822
2017-02-24 11:07:04 -08:00
George Melikov
298ec40b6d OpenZFS 7448 - ZFS doesn't notice when disk vdevs have no write cache
Authored by: Hans Rosenfeld <hans.rosenfeld@nexenta.com>
Reviewed by: Dan Fields <dan.fields@nexenta.com>
Reviewed by: Alek Pinchuk <alek.pinchuk@nexenta.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Reviewed-by: Don Brady <don.brady@intel.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/7448
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/295438b
Closes #5737
2017-02-04 09:23:50 -08:00
Brian Behlendorf
a32494d22a Fix suspend Godfather I/Os io_reexecute bits
After resuming a pool the godfather zio could have both the
ZIO_REEXECUTE_NOW and ZIO_REEXECUTE_SUSPEND bits set.  This
can occur if some child zios set ZIO_REEXECUTE_NOW while
other set ZIO_REEXECUTE_SUSPEND.  The godfather zio can
inherit both flags in zio_notify_parent().

The child zios which assigned the ZIO_REEXECUTE_SUSPEND flag
will be removed from the godfather's child list and added to
the spa->spa_suspend_zio_root child list.   While child zios
with the ZIO_REEXECUTE_NOW bit set remain being monitored
by the godfather zio.

When the godfather zio executes zio_done() the presence of
the ZIO_REEXECUTE_SUSPEND bit results in all io_reexecute
being cleared.  These child zios will then not be re-executed
and instead will be destroyed and lost.

The most straight forward way to address this situation is
to only clear the ZIO_REEXECUTE_SUSPEND bit and leave the
ZIO_REEXECUTE_NOW bit set.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: yuxiang <guo.yong33@zte.com.cn>
2017-01-28 12:13:34 -08:00
George Melikov
4ea3f86426 codebase style improvements for OpenZFS 6459 port 2017-01-22 13:25:40 -08:00
Don Brady
4e21fd060a OpenZFS 7303 - dynamic metaslab selection
This change introduces a new weighting algorithm to improve
metaslab selection. The new weighting algorithm relies on the
SPACEMAP_HISTOGRAM feature. As a result, the metaslab weight
now encodes the type of weighting algorithm used (size-based
vs segment-based).

Porting Notes: The metaslab allocation tracing code is conditionally
removed on linux (dependent on mdb debugger).

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Chris Siden <christopher.siden@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Pavel Zakharov pavel.zakharov@delphix.com
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Don Brady <don.brady@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Don Brady <don.brady@intel.com>

OpenZFS-issue: https://www.illumos.org/issues/7303
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d5190931bd
Closes #5404
2017-01-12 11:52:56 -08:00
George Melikov
e9aa730c49 OpenZFS 6328 - Fix cstyle errors in zfs codebase
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Jorgen Lundman <lundman@lundman.net>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/6328
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/9a686fb
Closes #5579
2017-01-12 09:42:11 -08:00
Brian Behlendorf
02730c333c Use cstyle -cpP in make cstyle check
Enable picky cstyle checks and resolve the new warnings.  The vast
majority of the changes needed were to handle minor issues with
whitespace formatting.  This patch contains no functional changes.

Non-whitespace changes are as follows:

* 8 times ; to { } in for/while loop
* fix missing ; in cmd/zed/agents/zfs_diagnosis.c
* comment (confim -> confirm)
* change endline , to ; in cmd/zpool/zpool_main.c
* a number of /* BEGIN CSTYLED */ /* END CSTYLED */ blocks
* /* CSTYLED */ markers
* change == 0 to !
* ulong to unsigned long in module/zfs/dsl_scan.c
* rearrangement of module_param lines in module/zfs/metaslab.c
* add { } block around statement after for_each_online_node

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5465
2016-12-12 10:46:26 -08:00
Brian Behlendorf
27f2b90d3e Revert "Disable zio_dva_throttle_enabled by default"
Enable zio_dva_throttle_enabled=1 by default. Subsequent
testing has been unable to reproduce the suspected regression.

Tested-by: kernelOfTruth kerneloftruth@gmail.com
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf behlendorf1@llnl.gov
Reverts #5335
Closes #5289
Closes #5457
2016-12-08 13:57:42 -07:00
David Quigley
a6255b7fce DLPX-44812 integrate EP-220 large memory scalability 2016-11-29 14:34:27 -08:00
Brian Behlendorf
34328f3cf8 Allow 16M zio buffers in user space
Only restrict the maximum zio alloc size to 32-bit kernel space.
The same virtual address space limitations don't apply to user
space.  This resolves a memory allocation failure in raidz_test
where it expects to be able to exercises all valid zio sizes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-11-07 10:26:17 -08:00
Brian Behlendorf
48d3eb40c7 Add TASKQID_INVALID
Add the TASKQID_INVALID macros and update callers to use the macro
instead of testing against 0.  There is no functional change
even though the functions in zfs_ctldir.c incorrectly used -1
instead of 0.

Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5347
2016-11-02 12:14:45 -07:00
Brian Behlendorf
76a87a902e Disable zio_dva_throttle_enabled by default
Until it can be determined definitively that a performance
regression wasn't introduced accidentally by 3dfb57a this
functionality is being disabled by default.  It can be re-
enabled by setting zio_dva_throttle_enabled=1.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5335 
Issue #5289
2016-10-26 09:13:43 -07:00
Brian Behlendorf
6d00b5e136 Fix unused variable
Accidentally introduced by 3dfb57a, when building with debugging
disabled several variables are unused.  Resolve this by wrapping
them in ASSERTV to remove them for non-debug builds.

Reviewed by: Don Brady <don.brady@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5284
2016-10-18 10:44:44 -07:00
Don Brady
3dfb57a35e OpenZFS 7090 - zfs should throttle allocations
OpenZFS 7090 - zfs should throttle allocations

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <paul.dagnelie@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Approved by: Matthew Ahrens <mahrens@delphix.com>
Ported-by: Don Brady <don.brady@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>

When write I/Os are issued, they are issued in block order but the ZIO
pipeline will drive them asynchronously through the allocation stage
which can result in blocks being allocated out-of-order. It would be
nice to preserve as much of the logical order as possible.

In addition, the allocations are equally scattered across all top-level
VDEVs but not all top-level VDEVs are created equally. The pipeline
should be able to detect devices that are more capable of handling
allocations and should allocate more blocks to those devices. This
allows for dynamic allocation distribution when devices are imbalanced
as fuller devices will tend to be slower than empty devices.

The change includes a new pool-wide allocation queue which would
throttle and order allocations in the ZIO pipeline. The queue would be
ordered by issued time and offset and would provide an initial amount of
allocation of work to each top-level vdev. The allocation logic utilizes
a reservation system to reserve allocations that will be performed by
the allocator. Once an allocation is successfully completed it's
scheduled on a given top-level vdev. Each top-level vdev maintains a
maximum number of allocations that it can handle (mg_alloc_queue_depth).
The pool-wide reserved allocations (top-levels * mg_alloc_queue_depth)
are distributed across the top-level vdevs metaslab groups and round
robin across all eligible metaslab groups to distribute the work. As
top-levels complete their work, they receive additional work from the
pool-wide allocation queue until the allocation queue is emptied.

OpenZFS-issue: https://www.illumos.org/issues/7090
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/4756c3d7
Closes #5258 

Porting Notes:
- Maintained minimal stack in zio_done
- Preserve linux-specific io sizes in zio_write_compress
- Added module params and documentation
- Updated to use optimize AVL cmp macros
2016-10-13 17:59:18 -07:00
Tony Hutter
3c67d83a8a OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported by: Tony Hutter <hutter2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/4185
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45818ee

Porting Notes:
This code is ported on top of the Illumos Crypto Framework code:

    b5e030c8db

The list of porting changes includes:

- Copied module/icp/include/sha2/sha2.h directly from illumos

- Removed from module/icp/algs/sha2/sha2.c:
	#pragma inline(SHA256Init, SHA384Init, SHA512Init)

- Added 'ctx' to lib/libzfs/libzfs_sendrecv.c:zio_checksum_SHA256() since
  it now takes in an extra parameter.

- Added CTASSERT() to assert.h from for module/zfs/edonr_zfs.c

- Added skein & edonr to libicp/Makefile.am

- Added sha512.S.  It was generated from sha512-x86_64.pl in Illumos.

- Updated ztest.c with new fletcher_4_*() args; used NULL for new CTX argument.

- In icp/algs/edonr/edonr_byteorder.h, Removed the #if defined(__linux) section
  to not #include the non-existant endian.h.

- In skein_test.c, renane NULL to 0 in "no test vector" array entries to get
  around a compiler warning.

- Fixup test files:
	- Rename <sys/varargs.h> -> <varargs.h>, <strings.h> -> <string.h>,
	- Remove <note.h> and define NOTE() as NOP.
	- Define u_longlong_t
	- Rename "#!/usr/bin/ksh" -> "#!/bin/ksh -p"
	- Rename NULL to 0 in "no test vector" array entries to get around a
	  compiler warning.
	- Remove "for isa in $($ISAINFO); do" stuff
	- Add/update Makefiles
	- Add some userspace headers like stdio.h/stdlib.h in places of
	  sys/types.h.

- EXPORT_SYMBOL *_Init/*_Update/*_Final... routines in ICP modules.

- Update scripts/zfs2zol-patch.sed

- include <sys/sha2.h> in sha2_impl.h

- Add sha2.h to include/sys/Makefile.am

- Add skein and edonr dirs to icp Makefile

- Add new checksums to zpool_get.cfg

- Move checksum switch block from zfs_secpolicy_setprop() to
  zfs_check_settable()

- Fix -Wuninitialized error in edonr_byteorder.h on PPC

- Fix stack frame size errors on ARM32
  	- Don't unroll loops in Skein on 32-bit to save stack space
  	- Add memory barriers in sha2.c on 32-bit to save stack space

- Add filetest_001_pos.ksh checksum sanity test

- Add option to write psudorandom data in file_write utility
2016-10-03 14:51:15 -07:00
Tom Caputi
c17bcf83da Enable raw writes to perform dedup with verification
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: David Quigley <david.quigley@intel.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Issue #5078
2016-09-13 09:59:04 -07:00
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
Brian Behlendorf
fcf64f45d9 Fix zdb crash with 4K-only devices
Here's the problem - on 4K native devices in userland on
Linux using O_DIRECT, buffers must be 4K aligned or I/O
will fail with EINVAL, causing zdb (and others) to coredump.
Since userland probably doesn't need optimized buffer caches,
we just force 4K alignment on everything.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #4479
2016-07-27 13:38:46 -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
Tony Hutter
26ef0cc7db OpenZFS 6531 - Provide mechanism to artificially limit disk performance
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Ported by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/6531
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/97e8130

Porting notes:
- Added new IO delay tracepoints, and moved common ZIO tracepoint macros
  to a new trace_common.h file.
- Used zio_delay_taskq() in place of OpenZFS's timeout_generic() function.
- Updated zinject man page
- Updated zpool_scrub test files
2016-05-26 10:11:51 -07:00
Tony Hutter
193a37cb24 Add -lhHpw options to "zpool iostat" for avg latency, histograms, & queues
Update the zfs module to collect statistics on average latencies, queue sizes,
and keep an internal histogram of all IO latencies.  Along with this, update
"zpool iostat" with some new options to print out the stats:

-l: Include average IO latencies stats:

 total_wait     disk_wait    syncq_wait    asyncq_wait  scrub
 read  write   read  write   read  write   read  write   wait
-----  -----  -----  -----  -----  -----  -----  -----  -----
    -   41ms      -    2ms      -   46ms      -    4ms      -
    -    5ms      -    1ms      -    1us      -    4ms      -
    -    5ms      -    1ms      -    1us      -    4ms      -
    -      -      -      -      -      -      -      -      -
    -   49ms      -    2ms      -   47ms      -      -      -
    -      -      -      -      -      -      -      -      -
    -    2ms      -    1ms      -      -      -    1ms      -
-----  -----  -----  -----  -----  -----  -----  -----  -----
  1ms    1ms    1ms  413us   16us   25us      -    5ms      -
  1ms    1ms    1ms  413us   16us   25us      -    5ms      -
  2ms    1ms    2ms  412us   26us   25us      -    5ms      -
    -    1ms      -  413us      -   25us      -    5ms      -
    -    1ms      -  460us      -   29us      -    5ms      -
196us    1ms  196us  370us    7us   23us      -    5ms      -
-----  -----  -----  -----  -----  -----  -----  -----  -----

-w: Print out latency histograms:

sdb           total           disk         sync_queue      async_queue
latency    read   write    read   write    read   write    read   write   scrub
-------  ------  ------  ------  ------  ------  ------  ------  ------  ------
1ns           0       0       0       0       0       0       0       0       0
...
33us          0       0       0       0       0       0       0       0       0
66us          0       0     107    2486       2     788      12      12       0
131us         2     797     359    4499      10     558     184     184       6
262us        22     801     264    1563      10     286     287     287      24
524us        87     575      71   52086      15    1063     136     136      92
1ms         152    1190       5   41292       4    1693     252     252     141
2ms         245    2018       0   50007       0    2322     371     371     220
4ms         189    7455      22  162957       0    3912    6726    6726     199
8ms         108    9461       0  102320       0    5775    2526    2526      86
17ms         23   11287       0   37142       0    8043    1813    1813      19
34ms          0   14725       0   24015       0   11732    3071    3071       0
67ms          0   23597       0    7914       0   18113    5025    5025       0
134ms         0   33798       0     254       0   25755    7326    7326       0
268ms         0   51780       0      12       0   41593   10002   10002       0
537ms         0   77808       0       0       0   64255   13120   13120       0
1s            0  105281       0       0       0   83805   20841   20841       0
2s            0   88248       0       0       0   73772   14006   14006       0
4s            0   47266       0       0       0   29783   17176   17176       0
9s            0   10460       0       0       0    4130    6295    6295       0
17s           0       0       0       0       0       0       0       0       0
34s           0       0       0       0       0       0       0       0       0
69s           0       0       0       0       0       0       0       0       0
137s          0       0       0       0       0       0       0       0       0
-------------------------------------------------------------------------------

-h: Help

-H: Scripted mode. Do not display headers, and separate fields by a single
    tab instead of arbitrary space.

-q: Include current number of entries in sync & async read/write queues,
    and scrub queue:

 syncq_read    syncq_write   asyncq_read  asyncq_write   scrubq_read
 pend  activ   pend  activ   pend  activ   pend  activ   pend  activ
-----  -----  -----  -----  -----  -----  -----  -----  -----  -----
    0      0      0      0     78     29      0      0      0      0
    0      0      0      0     78     29      0      0      0      0
    0      0      0      0      0      0      0      0      0      0
    -      -      -      -      -      -      -      -      -      -
    0      0      0      0      0      0      0      0      0      0
    -      -      -      -      -      -      -      -      -      -
    0      0      0      0      0      0      0      0      0      0
-----  -----  -----  -----  -----  -----  -----  -----  -----  -----
    0      0    227    394      0     19      0      0      0      0
    0      0    227    394      0     19      0      0      0      0
    0      0    108     98      0     19      0      0      0      0
    0      0     19     98      0      0      0      0      0      0
    0      0     78     98      0      0      0      0      0      0
    0      0     19     88      0      0      0      0      0      0
-----  -----  -----  -----  -----  -----  -----  -----  -----  -----

-p: Display numbers in parseable (exact) values.

Also, update iostat syntax to allow the user to specify specific vdevs
to show statistics for.  The three options for choosing pools/vdevs are:

Display a list of pools:
    zpool iostat ... [pool ...]

Display a list of vdevs from a specific pool:
    zpool iostat ... [pool vdev ...]

Display a list of vdevs from any pools:
    zpool iostat ... [vdev ...]

Lastly, allow zpool command "interval" value to be floating point:
    zpool iostat -v 0.5

Signed-off-by: Tony Hutter <hutter2@llnl.gov
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4433
2016-05-12 12:36:32 -07:00
Justin Gibbs
ee3a23b84e Illumos 5438 - zfs_blkptr_verify should continue after zfs_panic_recover
5438 zfs_blkptr_verify should continue after zfs_panic_recover
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Xin LI <delphij@freebsd.org>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5438
  https://github.com/illumos/illumos-gate/commit/5897eb4

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-01-12 13:54:05 -08:00
Matthew Ahrens
5511754b4f Illumos 6319 - assertion failed in zio_ddt_write: bp->blk_birth == txg
6319 assertion failed in zio_ddt_write: bp->blk_birth == txg
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/6319
  https://github.com/illumos/illumos-gate/commit/b39b744

Porting notes:
- Re-enabled ztest for CentOS test slaves.

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3449
2016-01-12 09:10:52 -08:00
Paul Dagnelie
fcff0f35bd Illumos 5960, 5925
5960 zfs recv should prefetch indirect blocks
5925 zfs receive -o origin=
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>

References:
  https://www.illumos.org/issues/5960
  https://www.illumos.org/issues/5925
  https://github.com/illumos/illumos-gate/commit/a2cdcdd

Porting notes:
- [lib/libzfs/libzfs_sendrecv.c]
  - b8864a2 Fix gcc cast warnings
  - 325f023 Add linux kernel device support
  - 5c3f61e Increase Linux pipe buffer size on 'zfs receive'
- [module/zfs/zfs_vnops.c]
  - 3558fd7 Prototype/structure update for Linux
  - c12e3a5 Restructure zfs_readdir() to fix regressions
- [module/zfs/zvol.c]
  - Function @zvol_map_block() isn't needed in ZoL
  - 9965059 Prefetch start and end of volumes
- [module/zfs/dmu.c]
  - Fixed ISO C90 - mixed declarations and code
  - Function dmu_prefetch() 'int i' is initialized before
    the following code block (c90 vs. c99)
- [module/zfs/dbuf.c]
  - fc5bb51 Fix stack dbuf_hold_impl()
  - 9b67f60 Illumos 4757, 4913
  - 34229a2 Reduce stack usage for recursive traverse_visitbp()
- [module/zfs/dmu_send.c]
  - Fixed ISO C90 - mixed declarations and code
  - b58986e Use large stacks when available
  - 241b541 Illumos 5959 - clean up per-dataset feature count code
  - 77aef6f Use vmem_alloc() for nvlists
  - 00b4602 Add linux kernel memory support

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-01-08 15:08:19 -08:00
Olaf Faaland
448d7aaabc Identify locks flagged by lockdep
When running a kernel with CONFIG_LOCKDEP=y, lockdep reports possible
recursive locking in some cases and possible circular locking dependency
in others, within the SPL and ZFS modules.

This patch uses a mutex type defined in SPL, MUTEX_NOLOCKDEP, to mark
such mutexes when they are initialized.  This mutex type causes
attempts to take or release those locks to be wrapped in lockdep_off()
and lockdep_on() calls to silence the dependency checker and allow the
use of lock_stats to examine contention.

For RW locks, it uses an analogous lock type, RW_NOLOCKDEP.

The goal is that these locks are ultimately changed back to type
MUTEX_DEFAULT or RW_DEFAULT, after the locks are annotated to reflect
their relationship (e.g. z_name_lock below) or any real problem with the
lock dependencies are fixed.

Some of the affected locks are:

tc_open_lock:
=============
This is an array of locks, all with same name, which txg_quiesce must
take all of in order to move txg to next state.  All default to the same
lockdep class, and so to lockdep appears recursive.

zp->z_name_lock:
================
In zfs_rmdir,
        dzp = znode for the directory (input to zfs_dirent_lock)
        zp  = znode for the entry being removed (output of zfs_dirent_lock)

zfs_rmdir()->zfs_dirent_lock() takes z_name_lock in dzp
zfs_rmdir() takes z_name_lock in zp

Since both dzp and zp are type znode_t, the locks have the same default
class, and lockdep considers it a possible recursive lock attempt.

l->l_rwlock:
============
zap_expand_leaf() sometimes creates two new zap leaf structures, via
these call paths:

zap_deref_leaf()->zap_get_leaf_byblk()->zap_leaf_open()
zap_expand_leaf()->zap_create_leaf()->zap_expand_leaf()->zap_create_leaf()

Because both zap_leaf_open() and zap_create_leaf() initialize
l->l_rwlock in their (separate) leaf structures, the lockdep class is
the same, and the linux kernel believes these might both be the same
lock, and emits a possible recursive lock warning.

Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3895
2015-12-22 10:21:33 -08:00
Brian Behlendorf
6fe53787f3 Fix vdev_queue_aggregate() deadlock
This deadlock may manifest itself in slightly different ways but
at the core it is caused by a memory allocation blocking on file-
system reclaim in the zio pipeline.  This is normally impossible
because zio_execute() disables filesystem reclaim by setting
PF_FSTRANS on the thread.  However, kmem cache allocations may
still indirectly block on file system reclaim while holding the
critical vq->vq_lock as shown below.

To resolve this issue zio_buf_alloc_flags() is introduced which
allocation flags to be passed.  This can then be used in
vdev_queue_aggregate() with KM_NOSLEEP when allocating the
aggregate IO buffer.  Since aggregating the IO is purely a
performance optimization we want this to either succeed or fail
quickly.  Trying too hard to allocate this memory under the
vq->vq_lock can negatively impact performance and result in
this deadlock.

* z_wr_iss
zio_vdev_io_start
  vdev_queue_io -> Takes vq->vq_lock
    vdev_queue_io_to_issue
      vdev_queue_aggregate
        zio_buf_alloc -> Waiting on spl_kmem_cache process

* z_wr_int
zio_vdev_io_done
  vdev_queue_io_done
    mutex_lock -> Waiting on vq->vq_lock held by z_wr_iss

* txg_sync
spa_sync
  dsl_pool_sync
    zio_wait -> Waiting on zio being handled by z_wr_int

* spl_kmem_cache
spl_cache_grow_work
  kv_alloc
    spl_vmalloc
      ...
      evict
        zpl_evict_inode
          zfs_inactive
            dmu_tx_wait
              txg_wait_open -> Waiting on txg_sync

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #3808
Closes #3867
2015-12-18 13:27:12 -08:00
Brian Behlendorf
b58986eebf Use large stacks when available
While stack size will vary by architecture it has historically defaulted to
8K on x86_64 systems.  However, as of Linux 3.15 the default thread stack
size was increased to 16K.  These kernels are now the default in most non-
enterprise distributions which means we no longer need to assume 8K stacks.

This patch takes advantage of that fact by appropriately reverting stack
conservation changes which were made to ensure stability.  Changes which
may have had a negative impact on performance for certain workloads.  This
also has the side effect of bringing the code slightly more in line with
upstream.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes #4059
2015-12-07 12:20:43 -08:00
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
Matthew Ahrens
c3520e7f1f Illumos 5818 - zfs {ref}compressratio is incorrect with 4k sector size
5818 zfs {ref}compressratio is incorrect with 4k sector size
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Approved by: Albert Lee <trisk@omniti.com>

References:
  https://www.illumos.org/issues/5818
  https://github.com/illumos/illumos-gate/commit/81cd5c5

Ported-by: Don Brady <don.brady@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3432
2015-06-10 16:24:01 -07:00
Matthew Ahrens
f1512ee61e Illumos 5027 - zfs large block support
5027 zfs large block support
Reviewed by: Alek Pinchuk <pinchuk.alek@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5027
  https://github.com/illumos/illumos-gate/commit/b515258

Porting Notes:

* Included in this patch is a tiny ISP2() cleanup in zio_init() from
Illumos 5255.

* Unlike the upstream Illumos commit this patch does not impose an
arbitrary 128K block size limit on volumes.  Volumes, like filesystems,
are limited by the zfs_max_recordsize=1M module option.

* By default the maximum record size is limited to 1M by the module
option zfs_max_recordsize.  This value may be safely increased up to
16M which is the largest block size supported by the on-disk format.
At the moment, 1M blocks clearly offer a significant performance
improvement but the benefits of going beyond this for the majority
of workloads are less clear.

* The illumos version of this patch increased DMU_MAX_ACCESS to 32M.
This was determined not to be large enough when using 16M blocks
because the zfs_make_xattrdir() function will fail (EFBIG) when
assigning a TX.  This was immediately observed under Linux because
all newly created files must have a security xattr created and
that was failing.  Therefore, we've set DMU_MAX_ACCESS to 64M.

* On 32-bit platforms a hard limit of 1M is set for blocks due
to the limited virtual address space.  We should be able to relax
this one the ABD patches are merged.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #354
2015-05-11 12:23:16 -07:00
Matthew Ahrens
63e3a8616b Illumos 5349 - verify that block pointer is plausible before reading
5349 verify that block pointer is plausible before reading
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Xin Li <delphij@FreeBSD.org>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References:
  https://www.illumos.org/issues/5349
  https://github.com/illumos/illumos-gate/commit/f63ab3d5

Porting notes:
* Several variable declarations were moved due to C style needs

Ported-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3373
2015-05-08 14:09:15 -07:00
Matthew Ahrens
7a3066ffdd Illumos 5348 - zio_checksum_error() only fills in info if ECKSUM
5348 zio_checksum_error() only fills in info if ECKSUM
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5348
  https://github.com/illumos/illumos-gate/commit/373dc1cf

Ported-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3372
2015-05-05 11:05:37 -07:00
George Wilson
98b254188a Illumos #5244 - zio pipeline callers should explicitly invoke next stage
5244 zio pipeline callers should explicitly invoke next stage
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Approved by: Gordon Ross <gwr@nexenta.com>

References:
  https://www.illumos.org/issues/5244
  https://github.com/illumos/illumos-gate/commit/738f37b

Porting Notes:

1. The unported "2932 support crash dumps to raidz, etc. pools"
   caused a merge conflict due to a copyright difference in
   module/zfs/vdev_raidz.c.
2. The unported "4128 disks in zpools never go away when pulled"
   and additional Linux-specific changes caused merge conflicts in
   module/zfs/vdev_disk.c.

Ported-by: Richard Yao <richard.yao@clusterhq.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2828
2015-04-30 15:07:47 -07:00
Matthew Ahrens
0f7d2a4b3d Illumus 5693 - ztest fails in dbuf_verify: buf[i] == 0, due to dedup and bp_override
5693 ztest fails in dbuf_verify: buf[i] == 0, due to dedup and bp_override
Reviewed by: George Wilson <george@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Bayard Bell <buffer.g.overflow@gmail.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5693
  https://github.com/illumos/illumos-gate/commit/7f7ace3

Ported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3231
2015-03-27 15:02:56 -07:00
Isaac Huang
e89bd69775 zio_injection_enabled should not be a module option
The zio_inject.c keeps zio_injection_enabled as a counter of
fault handlers, so it should not be exported to user space as
a module option.

Several EXPORT_SYMBOLs are moved from zio.c to zio_inject.c,
where the symbols are defined.

Signed-off-by: Isaac Huang <he.huang@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3199
2015-03-24 13:22:03 -07:00
Brian Behlendorf
3941503c0a Retire zio_cons()/zio_dest()
The zio_cons() constructor and zio_dest() destructor don't exist
in the upstream Illumos code.  They were introduced as a workaround
to avoid issue #2523.  Since this issue has now been resolved this
code is being reverted to bring ZoL back in sync with Illumos.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Issue #3063
2015-02-10 16:09:49 -08:00
Brian Behlendorf
6442f3cfe3 Retire zio_bulk_flags
Long ago the zio_bulk_flags module parameter was introduced to
facilitate debugging and profiling the zio_buf_caches.  Today
this code works well and there's no compelling reason to keep
this functionality.  In fact it's preferable to revert this so
the code is more consistent with other ZFS implementations.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Issue #3063
2015-02-10 16:08:49 -08:00
Brian Behlendorf
81971b137a Revert "SA spill block cache"
The SA spill_cache was originally introduced to avoid the need to
perform large kmem or vmem allocations.  Instead a small dedicated
cache of preallocated SA buffers was kept.

This solution was viable while the maximum block size was limited
to 128K.  But with the planned increase of the maximum block size
to 16M callers need to migrate to the zio_buf_alloc().  However,
they should be aware this interface is expected to change again
once the zio buffers are fully backed by scatter-gather lists.

Alternately, if the callers know these buffers will never be large
or be infrequently accessed they may kmem_alloc() or vmem_alloc()
the needed temporary space.

This change has the additional benegit of bringing the code back
inline with the upstream Illumos source.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:28 -08:00
Brian Behlendorf
285b29d959 Revert "Pre-allocate vdev I/O buffers"
Commit 86dd0fd added preallocated I/O buffers.  This is no longer
required after the recent kmem changes designed to make our memory
allocation interfaces behave more like those found on Illumos.  A
deadlock in this situation is no longer possible.

However, these allocations still have the potential to be expensive.
So a potential future optimization might be to perform then KM_NOSLEEP
so that they either succeed of fail quicky.  Either case is acceptable
here because we can safely abort the aggregation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:28 -08:00
Brian Behlendorf
79c76d5b65 Change KM_PUSHPAGE -> KM_SLEEP
By marking DMU transaction processing contexts with PF_FSTRANS
we can revert the KM_PUSHPAGE -> KM_SLEEP changes.  This brings
us back in line with upstream.  In some cases this means simply
swapping the flags back.  For others fnvlist_alloc() was replaced
by nvlist_alloc(..., KM_PUSHPAGE) and must be reverted back to
fnvlist_alloc() which assumes KM_SLEEP.

The one place KM_PUSHPAGE is kept is when allocating ARC buffers
which allows us to dip in to reserved memory.  This is again the
same as upstream.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:41:26 -08:00
Brian Behlendorf
efcd79a883 Retire KM_NODEBUG
Callers of kmem_alloc() which passed the KM_NODEBUG flag to suppress
the large allocation warning have been replaced by vmem_alloc() as
appropriate.  The updated vmem_alloc() call will not print a warning
regardless of the size of the allocation.

A careful reader will notice that not all callers have been changed
to vmem_alloc().  Some have only had the KM_NODEBUG flag removed.
This was possible because the default warning threshold has been
increased to 32k.  This is desirable because it minimizes the need
for Linux specific code changes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:40:32 -08:00
Brian Behlendorf
92119cc259 Mark IO pipeline with PF_FSTRANS
In order to avoid deadlocking in the IO pipeline it is critical that
pageout be avoided during direct memory reclaim.  This ensures that
the pipeline threads can always make forward progress and never end
up blocking on a DMU transaction.  For this very reason Linux now
provides the PF_FSTRANS flag which may be set in the process context.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 14:28:05 -08:00
Alex Reece
b02fe35d37 Illumos 4958 zdb trips assert on pools with ashift >= 0xe
4958 zdb trips assert on pools with ashift >= 0xe
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/4958
  https://github.com/illumos/illumos-gate/commit/2a104a5

Porting notes:

Keep the ZIO_FLAG_FASTWRITE define.  This is for a feature present
in Linux but not yet in *BSD.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2697
2014-10-23 15:30:32 -07:00
Brian Behlendorf
8878261fc9 Fix CPU_SEQID use in preemptible context
Commit e022864 introduced a regression for kernels which are built
with CONFIG_DEBUG_PREEMPT.  The use of CPU_SEQID in a preemptible
context causes zio_nowait() to trigger the BUG.  Since CPU_SEQID
is simply being used as a random index the usage here is safe. To
resolve the issue preempt is disable while calling CPU_SEQID.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #2769
2014-10-07 16:40:29 -07:00
Matthew Ahrens
e022864d19 Illumos 5176 - lock contention on godfather zio
5176 lock contention on godfather zio
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Alex Reece <alex.reece@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Reviewed by: Bayard Bell <Bayard.Bell@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/5176
  https://github.com/illumos/illumos-gate/commit/6f834bc

Porting notes:

Under Linux max_ncpus is defined as num_possible_cpus().  This is
largest number of cpu ids which might be available during the life
time of the system boot.  This value can be larger than the number
of present cpus if CONFIG_HOTPLUG_CPU is defined.

Ported by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2711
2014-10-07 11:24:24 -07:00
Matthew Ahrens
5dbd68a352 Illumos 4914 - zfs on-disk bookmark structure should be named *_phys_t
4914 zfs on-disk bookmark structure should be named *_phys_t

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Robert Mustacchi <rm@joyent.com>

References:
  https://www.illumos.org/issues/4914
  https://github.com/illumos/illumos-gate/commit/7802d7b

Porting notes:

There were a number of zfsonlinux-specific uses of zbookmark_t which
needed to be updated.  This should reduce the likelihood of further
problems like issue #2094 from occurring.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2558
2014-08-06 14:48:41 -07:00
Matthew Ahrens
fbeddd60b7 Illumos 4390 - I/O errors can corrupt space map when deleting fs/vol
4390 i/o errors when deleting filesystem/zvol can lead to space map corruption
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4390
  https://github.com/illumos/illumos-gate/commit/7fd05ac

Porting notes:

Previous stack-reduction efforts in traverse_visitb() caused a fair
number of un-mergable pieces of code.  This patch should reduce its
stack footprint a bit more.

The new local bptree_entry_phys_t in bptree_add() is dynamically-allocated
using kmem_zalloc() for the purpose of stack reduction.

The new global zfs_free_leak_on_eio has been defined as an integer
rather than a boolean_t as was the case with the related zfs_recover
global.  Also, zfs_free_leak_on_eio's definition has been inserted into
zfs_debug.c for consistency with the existing definition of zfs_recover.
Illumos placed it in spa_misc.c.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2545
2014-08-04 11:50:52 -07:00
Matthew Ahrens
9b67f60560 Illumos 4757, 4913
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4757
  https://www.illumos.org/issues/4913
  https://github.com/illumos/illumos-gate/commit/5d7b4d4

Porting notes:

For compatibility with the fastpath code the zio_done() function
needed to be updated.  Because embedded-data block pointers do
not require DVAs to be allocated the associated vdevs will not
be marked and therefore should not be unmarked.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2544
2014-08-01 14:28:05 -07:00
George Wilson
672692c7b7 Illumos 4754, 4755
4754 io issued to near-full luns even after setting noalloc threshold
4755 mg_alloc_failures is no longer needed

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4754
  https://www.illumos.org/issues/4755
  https://github.com/illumos/illumos-gate/commit/b6240e8

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2533
2014-07-30 10:30:05 -07:00
Matthew Ahrens
9bd274ddd8 Illumos #4374
4374 dn_free_ranges should use range_tree_t

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com
Reviewed by: Garrett D'Amore <garrett@damore.org>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4374
  https://github.com/illumos/illumos-gate/commit/bf16b11

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2531
2014-07-30 09:20:35 -07:00
Max Grossman
b0bc7a84d9 Illumos 4370, 4371
4370 avoid transmitting holes during zfs send
4371 DMU code clean up

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Garrett D'Amore <garrett@damore.org>a

References:
  https://www.illumos.org/issues/4370
  https://www.illumos.org/issues/4371
  https://github.com/illumos/illumos-gate/commit/43466aa

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2529
2014-07-28 14:29:58 -07:00
Brian Behlendorf
7f6884f419 Revert "Fix __zio_execute() asynchronous dispatch"
This reverts commit 91579709fc which
limited the asynchronous dispatch to kernel space.  We want to do
this for two reasons:

1) While we have slightly more headroom in user space excessively
   deep stacks have been observed while running ztest, see #2293.

2) Removing this conditional makes the pipeline behave consistently
   regardless of if it's executing in kernel space or user space.
   This way we're more likely to uncover subtle issues with ztest.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2384
2014-06-11 16:32:57 -07:00
Brian Behlendorf
6795a698f4 Use default slab types
We should not override the default memory type of the kmem cache.  This
was done previously to force certain objects which were slightly over
object size limit cut off in to KMC_KMEM caches for better performance.

The zfsonlinux/spl#356 patch slightly increases the default cut off
from 511 bytes 1024 bytes for x86_64.  This means there is long longer
a need to override the default for the caches.  And since the default
values are now being used the new spl_kmem_cache_slab_limit and
spl_kmem_cache_kmem_limit tunables will apply to all kmem caches.

The following is a list of caches that will be impacted:

                  | object size   | forced type   | default type
----------------- | ------------- | ------------- | --------------
dnode_t           | 936 bytes     | KMC_KMEM      | KMC_KMEM
zio_cache         | 1104 bytes    | *KMC_KMEM     | *KMC_VMEM
zio_link_cache    | 48 bytes      | KMC_KMEM      | KMC_KMEM
zio_vdev_cache    | 131088 bytes  | KMC_VMEM      | KMC_VMEM
zio_buf_512       | 512 bytes     | KMC_KMEM      | KMC_KMEM
zio_data_buf_512  | 512 bytes     | KMC_KMEM      | KMC_KMEM
zio_buf_1024      | 1024 bytes    | KMC_KMEM      | KMC_KMEM
zio_data_buf_1024 | 1024 bytes    | +KMC_VMEM     | +KMC_KMEM

* Cache memory type will change from KMC_KMEM to KMC_VMEM.
+ Cache memory type will change from KMC_VMEM to KMC_KMEM.

This patch removes another slight point of divergence between ZoL
and Illumos.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Closes #2337
2014-05-22 10:39:52 -07:00
Michael Kjorling
d1d7e2689d cstyle: Resolve C style issues
The vast majority of these changes are in Linux specific code.
They are the result of not having an automated style checker to
validate the code when it was originally written.  Others were
caused when the common code was slightly adjusted for Linux.

This patch contains no functional changes.  It only refreshes
the code to conform to style guide.

Everyone submitting patches for inclusion upstream should now
run 'make checkstyle' and resolve any warning prior to opening
a pull request.  The automated builders have been updated to
fail a build if when 'make checkstyle' detects an issue.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1821
2013-12-18 16:46:35 -08:00
Matthew Ahrens
e8b96c6007 Illumos #4045 write throttle & i/o scheduler performance work
4045 zfs write throttle & i/o scheduler performance work

1. The ZFS i/o scheduler (vdev_queue.c) now divides i/os into 5 classes: sync
read, sync write, async read, async write, and scrub/resilver.  The scheduler
issues a number of concurrent i/os from each class to the device.  Once a class
has been selected, an i/o is selected from this class using either an elevator
algorithem (async, scrub classes) or FIFO (sync classes).  The number of
concurrent async write i/os is tuned dynamically based on i/o load, to achieve
good sync i/o latency when there is not a high load of writes, and good write
throughput when there is.  See the block comment in vdev_queue.c (reproduced
below) for more details.

2. The write throttle (dsl_pool_tempreserve_space() and
txg_constrain_throughput()) is rewritten to produce much more consistent delays
when under constant load.  The new write throttle is based on the amount of
dirty data, rather than guesses about future performance of the system.  When
there is a lot of dirty data, each transaction (e.g. write() syscall) will be
delayed by the same small amount.  This eliminates the "brick wall of wait"
that the old write throttle could hit, causing all transactions to wait several
seconds until the next txg opens.  One of the keys to the new write throttle is
decrementing the amount of dirty data as i/o completes, rather than at the end
of spa_sync().  Note that the write throttle is only applied once the i/o
scheduler is issuing the maximum number of outstanding async writes.  See the
block comments in dsl_pool.c and above dmu_tx_delay() (reproduced below) for
more details.

This diff has several other effects, including:

 * the commonly-tuned global variable zfs_vdev_max_pending has been removed;
use per-class zfs_vdev_*_max_active values or zfs_vdev_max_active instead.

 * the size of each txg (meaning the amount of dirty data written, and thus the
time it takes to write out) is now controlled differently.  There is no longer
an explicit time goal; the primary determinant is amount of dirty data.
Systems that are under light or medium load will now often see that a txg is
always syncing, but the impact to performance (e.g. read latency) is minimal.
Tune zfs_dirty_data_max and zfs_dirty_data_sync to control this.

 * zio_taskq_batch_pct = 75 -- Only use 75% of all CPUs for compression,
checksum, etc.  This improves latency by not allowing these CPU-intensive tasks
to consume all CPU (on machines with at least 4 CPU's; the percentage is
rounded up).

--matt

APPENDIX: problems with the current i/o scheduler

The current ZFS i/o scheduler (vdev_queue.c) is deadline based.  The problem
with this is that if there are always i/os pending, then certain classes of
i/os can see very long delays.

For example, if there are always synchronous reads outstanding, then no async
writes will be serviced until they become "past due".  One symptom of this
situation is that each pass of the txg sync takes at least several seconds
(typically 3 seconds).

If many i/os become "past due" (their deadline is in the past), then we must
service all of these overdue i/os before any new i/os.  This happens when we
enqueue a batch of async writes for the txg sync, with deadlines 2.5 seconds in
the future.  If we can't complete all the i/os in 2.5 seconds (e.g. because
there were always reads pending), then these i/os will become past due.  Now we
must service all the "async" writes (which could be hundreds of megabytes)
before we service any reads, introducing considerable latency to synchronous
i/os (reads or ZIL writes).

Notes on porting to ZFS on Linux:

- zio_t gained new members io_physdone and io_phys_children.  Because
  object caches in the Linux port call the constructor only once at
  allocation time, objects may contain residual data when retrieved
  from the cache. Therefore zio_create() was updated to zero out the two
  new fields.

- vdev_mirror_pending() relied on the depth of the per-vdev pending queue
  (vq->vq_pending_tree) to select the least-busy leaf vdev to read from.
  This tree has been replaced by vq->vq_active_tree which is now used
  for the same purpose.

- vdev_queue_init() used the value of zfs_vdev_max_pending to determine
  the number of vdev I/O buffers to pre-allocate.  That global no longer
  exists, so we instead use the sum of the *_max_active values for each of
  the five I/O classes described above.

- The Illumos implementation of dmu_tx_delay() delays a transaction by
  sleeping in condition variable embedded in the thread
  (curthread->t_delay_cv).  We do not have an equivalent CV to use in
  Linux, so this change replaced the delay logic with a wrapper called
  zfs_sleep_until(). This wrapper could be adopted upstream and in other
  downstream ports to abstract away operating system-specific delay logic.

- These tunables are added as module parameters, and descriptions added
  to the zfs-module-parameters.5 man page.

  spa_asize_inflation
  zfs_deadman_synctime_ms
  zfs_vdev_max_active
  zfs_vdev_async_write_active_min_dirty_percent
  zfs_vdev_async_write_active_max_dirty_percent
  zfs_vdev_async_read_max_active
  zfs_vdev_async_read_min_active
  zfs_vdev_async_write_max_active
  zfs_vdev_async_write_min_active
  zfs_vdev_scrub_max_active
  zfs_vdev_scrub_min_active
  zfs_vdev_sync_read_max_active
  zfs_vdev_sync_read_min_active
  zfs_vdev_sync_write_max_active
  zfs_vdev_sync_write_min_active
  zfs_dirty_data_max_percent
  zfs_delay_min_dirty_percent
  zfs_dirty_data_max_max_percent
  zfs_dirty_data_max
  zfs_dirty_data_max_max
  zfs_dirty_data_sync
  zfs_delay_scale

  The latter four have type unsigned long, whereas they are uint64_t in
  Illumos.  This accommodates Linux's module_param() supported types, but
  means they may overflow on 32-bit architectures.

  The values zfs_dirty_data_max and zfs_dirty_data_max_max are the most
  likely to overflow on 32-bit systems, since they express physical RAM
  sizes in bytes.  In fact, Illumos initializes zfs_dirty_data_max_max to
  2^32 which does overflow. To resolve that, this port instead initializes
  it in arc_init() to 25% of physical RAM, and adds the tunable
  zfs_dirty_data_max_max_percent to override that percentage.  While this
  solution doesn't completely avoid the overflow issue, it should be a
  reasonable default for most systems, and the minority of affected
  systems can work around the issue by overriding the defaults.

- Fixed reversed logic in comment above zfs_delay_scale declaration.

- Clarified comments in vdev_queue.c regarding when per-queue minimums take
  effect.

- Replaced dmu_tx_write_limit in the dmu_tx kstat file
  with dmu_tx_dirty_delay and dmu_tx_dirty_over_max.  The first counts
  how many times a transaction has been delayed because the pool dirty
  data has exceeded zfs_delay_min_dirty_percent.  The latter counts how
  many times the pool dirty data has exceeded zfs_dirty_data_max (which
  we expect to never happen).

- The original patch would have regressed the bug fixed in
  zfsonlinux/zfs@c418410, which prevented users from setting the
  zfs_vdev_aggregation_limit tuning larger than SPA_MAXBLOCKSIZE.
  A similar fix is added to vdev_queue_aggregate().

- In vdev_queue_io_to_issue(), dynamically allocate 'zio_t search' on the
  heap instead of the stack.  In Linux we can't afford such large
  structures on the stack.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Ned Bass <bass6@llnl.gov>
Reviewed by: Brendan Gregg <brendan.gregg@joyent.com>
Approved by: Robert Mustacchi <rm@joyent.com>

References:
  http://www.illumos.org/issues/4045
  illumos/illumos-gate@69962b5647

Ported-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1913
2013-12-06 09:32:43 -08:00
George Wilson
ac72fac3ea Illumos #3954, #4080, #4081
3954 metaslabs continue to load even after hitting zfs_mg_alloc_failure limit
4080 zpool clear fails to clear pool
4081 need zfs_mg_noalloc_threshold
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/3954
  https://www.illumos.org/issues/4080
  https://www.illumos.org/issues/4081
  illumos/illumos-gate@22e30981d8

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
2013-11-05 12:25:01 -08:00
Matthew Ahrens
2883cad5b7 Illumos #3836
3836 zio_free() can be processed immediately in the common case
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/3836
  illumos/illumos-gate@9cb154a3c9

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
2013-11-05 12:14:56 -08:00
Matthew Ahrens
498877baf5 Illumos #3112, #3113, #3114
3112 ztest does not honor ZFS_DEBUG
3113 ztest should use watchpoints to protect frozen arc bufs
3114 some leaked nvlists in zfsdev_ioctl

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Amdur <Matt.Amdur@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References:
  https://www.illumos.org/issues/3112
  https://www.illumos.org/issues/3113
  https://www.illumos.org/issues/3114
  illumos/illumos-gate@cd1c8b85eb

The /proc/self/cmd watchpoint interface is specific to Solaris.
Therefore, the #3113 implementation was reworked to use the more
portable mprotect(2) system call.  When the pages are watched they
are marked read-only for protection.  Any write to the protected
address range immediately trigger a SIGSEGV.  The pages are marked
writable again when they are unwatched.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
2013-11-05 12:14:48 -08:00
George Wilson
03c6040bee Illumos #3236
3236 zio nop-write
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  illumos/illumos-gate@80901aea8e
  https://www.illumos.org/issues/3236

Porting Notes

1. This patch is being merged dispite an increased instance of
   https://www.illumos.org/issues/3113 being triggered by ztest.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1489
2013-11-05 12:14:21 -08:00
Matthew Ahrens
2e528b49f8 Illumos #3598
3598 want to dtrace when errors are generated in zfs
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/3598
  illumos/illumos-gate@be6fd75a69

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775

Porting notes:

1. include/sys/zfs_context.h has been modified to render some new
   macros inert until dtrace is available on Linux.

2. Linux-specific changes have been adapted to use SET_ERROR().

3. I'm NOT happy about this change.  It does nothing but ugly
   up the code under Linux.  Unfortunately we need to take it to
   avoid more merge conflicts in the future.  -Brian
2013-10-31 14:58:04 -07:00
Richard Yao
8c8417933f Fix order of function calls in zio_free_sync()
The resolution of a merge conflict when merging Illumos #3464 caused us
to invert the order couple of function calls in zio_free_sync() versus
what they are in Illumos.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
2013-10-29 15:06:18 -07:00
Matthew Ahrens
13fe019870 Illumos #3464
3464 zfs synctask code needs restructuring
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/3464
  illumos/illumos-gate@3b2aab1880

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1495
2013-09-04 16:01:24 -07:00
Brian Behlendorf
34e143323e Fix z_wr_iss_h zio_execute() import hang
Because we need to be more frugal about our stack usage under
Linux.  The __zio_execute() function was modified to re-dispatch
zios to a ZIO_TASKQ_ISSUE thread when we're in a context which
is known to be stack heavy.  Those two contexts are the sync
thread and what ever thread is performing spa initialization.

Unfortunately, this change introduced an unlikely bug which can
result in a zio being re-dispatched indefinitely and never being
executed.  If during spa initialization we handle a zio with
ZIO_PRIORITY_NOW it will be moved to the high priority queue.
When __zio_execute() is called again for the zio it will mis-
interpret the context and re-dispatch it again.  The system
will get stuck spinning re-dispatching the zio and making no
forward progress.

To fix this rare issue __zio_execute() has been updated not
to re-dispatch zios on either the ZIO_TASKQ_ISSUE or
ZIO_TASKQ_ISSUE_HIGH task queues.

In practice this issue was rarely reported and can usually
be fixed by rebooting the system and importing the pool again.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1455
2013-08-15 15:20:36 -07:00
Richard Yao
4edbd2f79a Remove zio_alloc_arena
We declare zio_alloc_arena using extern, but it does not appear to exist
anywhere in the code. This permits undefined behavior, so lets remove
it.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1614
2013-08-01 09:48:06 -07:00
Brian Behlendorf
bf89c19914 Log pool suspension warnings to the console
In the event that a pool gets suspended log this information to
the console.  This is critical information and we want to make
sure it gets logged.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1555
2013-07-10 15:15:52 -07:00
Shen Yan
8e07b99b2f Update zio.c
The cv_wait_io is used to account io time instead of cv_wait.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1566
2013-07-09 10:41:46 -07:00
George Wilson
294f68063b Illumos #3498 panic in arc_read()
3498 panic in arc_read(): !refcount_is_zero(&pbuf->b_hdr->b_refcnt)
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  illumos/illumos-gate@1b912ec710
  https://www.illumos.org/issues/3498

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1249
2013-07-02 13:34:31 -07:00
Cyril Plisko
29dee3ee9a Add zfs_sync_pass_* tunable parameters
Commit 55d85d5a8c (backport of
the upstream changes) replaced three hardcoded constants:

    #define SYNC_PASS_DEFERRED_FREE 2 /* defer frees after this pass */
    #define SYNC_PASS_DONT_COMPRESS 4 /* don't compress after this pass */
    #define SYNC_PASS_REWRITE       1 /* rewrite new bps after this pass */

with a tunable parameters:

    int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */
    int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */
    int zfs_sync_pass_rewrite = 2;       /* rewrite new bps starting in this pass */

This commit makes these tunables available as module parameters
in Linux.  They should only be used for performance analysis
because changing them can result in subtle and pathological
performance problems.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1562
2013-07-02 09:34:18 -07:00
Matthew Ahrens
df4474f92d Illumos #3805 arc shouldn't cache freed blocks
3805 arc shouldn't cache freed blocks
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Richard Elling <richard.elling@dey-sys.com>
Reviewed by: Will Andrews <will@firepipe.net>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  illumos/illumos-gate@6e6d5868f5
  https://www.illumos.org/issues/3805

ZFS should proactively evict freed blocks from the cache.

On dcenter, we saw that we were caching ~256GB of metadata, while the
pool only had <4GB of metadata on disk.  We were wasting about half the
system's RAM (252GB) on blocks that have been freed.

Even though these freed blocks will never be used again, and thus will
eventually be evicted, this causes us to use memory inefficiently for 2
reasons:

1. A block that is freed has no chance of being accessed again, but will
be kept in memory preferentially to a block that was accessed before it
(and is thus older) but has not been freed and thus has at least some
chance of being accessed again.

2. We partition the ARC into several buckets:
user data that has been accessed only once (MRU)
metadata that has been accessed only once (MRU)
user data that has been accessed more than once (MFU)
metadata that has been accessed more than once (MFU)

The user data vs metadata split is somewhat arbitrary, and the primary
control on how much memory is used to cache data vs metadata is to
simply try to keep the proportion the same as it has been in the past
(each bucket "evicts against" itself).  The secondary control is to
evict data before evicting metadata.

Because of this bucketing, we may end up with one bucket mostly
containing freed blocks that are very old, while another bucket has more
recently accessed, still-allocated blocks.  Data in the useful bucket
(with still-allocated blocks) may be evicted in preference to data in
the useless bucket (with old, freed blocks).

On dcenter, we saw that the MFU metadata bucket was 230MB, while the MFU
data bucket was 27GB and the MRU metadata bucket was 256GB.  However,
the vast majority of data in the MRU metadata bucket (256GB) was freed
blocks, and thus useless.  Meanwhile, the MFU metadata bucket (230MB)
was constantly evicting useful blocks that will be soon needed.

The problem of cache segmentation is a larger problem that needs more
investigation.  However, if we stop caching freed blocks, it should
reduce the impact of this more fundamental issue.

Ported-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1503
2013-06-20 09:55:52 -07:00
Madhav Suresh
c99c90015e Illumos #3006
3006 VERIFY[S,U,P] and ASSERT[S,U,P] frequently check if first
     argument is zero

Reviewed by Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by George Wilson <george.wilson@delphix.com>
Approved by Eric Schrock <eric.schrock@delphix.com>

References:
  illumos/illumos-gate@fb09f5aad4
  https://illumos.org/issues/3006

Requires:
  zfsonlinux/spl@1c6d149feb

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1509
2013-06-19 15:14:10 -07:00
Adam Leventhal
7ef5e54e2e Illumos #3581 spa_zio_taskq[ZIO_TYPE_FREE][ZIO_TASKQ_ISSUE]->tq_lock contention
3581 spa_zio_taskq[ZIO_TYPE_FREE][ZIO_TASKQ_ISSUE]->tq_lock is piping hot

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Gordon Ross <gordon.ross@nexenta.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  illumos/illumos-gate@ec94d32
  https://illumos.org/issues/3581

Notes for Linux port:

Earlier commit 08d08eb reduced contention on this taskq lock by simply
reducing the number of z_fr_iss threads from 100 to one-per-CPU.  We
also optimized the taskq implementation in zfsonlinux/spl@3c6ed54.
These changes significantly improved unlink performance to acceptable
levels.

This patch further reduces time spent spinning on this lock by
randomly dispatching the work items over multiple independent task
queues.  The Illumos ZFS developers stated that this lock contention
only arose after "3329 spa_sync() spends 10-20% of its time in
spa_free_sync_cb()" was landed.  It's not clear if 3329 affects the
Linux port or not.  I didn't see spa_free_sync_cb() show up in
oprofile sessions while unlinking large files, but I may just not
have used the right test case.

I tested unlinking a 1 TB of data with and without the patch and
didn't observe a meaningful difference in elapsed time.  However,
oprofile showed that the percent time spent in taskq_thread() was
reduced from about 16% to about 5%.  Aside from a possible slight
performance benefit this may be worth landing if only for the sake of
maintaining consistency with upstream.

Ported-by: Ned Bass <bass6@llnl.gov>
Closes #1327
2013-05-06 14:05:37 -07:00
George Wilson
55d85d5a8c Illumos #3329, #3330, #3331, #3335
3329 spa_sync() spends 10-20% of its time in spa_free_sync_cb()
3330 space_seg_t should have its own kmem_cache
3331 deferred frees should happen after sync_pass 1
3335 make SYNC_PASS_* constants tunable

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Approved by: Eric Schrock <eric.schrock@delphix.com>

References:
  illumos/illumos-gate@01f55e48fb
  https://www.illumos.org/issues/3329
  https://www.illumos.org/issues/3330
  https://www.illumos.org/issues/3331
  https://www.illumos.org/issues/3335

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-05-06 12:39:34 -07:00
George Wilson
5853fe790d Illumos #3306, #3321
3306 zdb should be able to issue reads in parallel
3321 'zpool reopen' command should be documented in the man
     page and help

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  illumos/illumos-gate@31d7e8fa33
  https://www.illumos.org/issues/3306
  https://www.illumos.org/issues/3321

The vdev_file.c implementation in this patch diverges significantly
from the upstream version.  For consistenty with the vdev_disk.c
code the upstream version leverages the Illumos bio interfaces.
This makes sense for Illumos but not for ZoL for two reasons.

1) The vdev_disk.c code in ZoL has been rewritten to use the
   Linux block device interfaces which differ significantly
   from those in Illumos.  Therefore, updating the vdev_file.c
   to use the Illumos interfaces doesn't get you consistency
   with vdev_disk.c.

2) Using the upstream patch as is would requiring implementing
   compatibility code for those Solaris block device interfaces
   in user and kernel space.  That additional complexity could
   lead to confusion and doesn't buy us anything.

For these reasons I've opted to simply move the existing vn_rdwr()
as is in to the taskq function.  This has the advantage of being
low risk and easy to understand.  Moving the vn_rdwr() function
in to its own taskq thread also neatly avoids the possibility of
a stack overflow.

Finally, because of the additional work which is being handled by
the free taskq the number of threads has been increased.  The
thread count under Illumos defaults to 100 but was decreased to 2
in commit 08d08e due to contention.  We increase it to 8 until
the contention can be address by porting Illumos #3581.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1354
2013-05-03 16:53:52 -07:00
George.Wilson
cc92e9d0c3 3246 ZFS I/O deadman thread
Reviewed by: Matt Ahrens <matthew.ahrens@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Christopher Siden <chris.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

NOTES: This patch has been reworked from the original in the
following ways to accomidate Linux ZFS implementation

*) Usage of the cyclic interface was replaced by the delayed taskq
   interface.  This avoids the need to implement new compatibility
   code and allows us to rely on the existing taskq implementation.

*) An extern for zfs_txg_synctime_ms was added to sys/dsl_pool.h
   because declaring externs in source files as was done in the
   original patch is just plain wrong.

*) Instead of panicing the system when the deadman triggers a
   zevent describing the blocked vdev and the first pending I/O
   is posted.  If the panic behavior is desired Linux provides
   other generic methods to panic the system when threads are
   observed to hang.

*) For reference, to delay zios by 30 seconds for testing you can
   use zinject as follows: 'zinject -d <vdev> -D30 <pool>'

References:
  illumos/illumos-gate@283b84606b
  https://www.illumos.org/issues/3246

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1396
2013-05-01 17:05:52 -07:00
Brian Behlendorf
5dc6af0eec Add zio_ddt_free()+ddt_phys_decref() error handling
The assumption in zio_ddt_free() is that ddt_phys_select() must
always find a match.  However, if that fails due to a damaged
DDT or some other reason the code will NULL dereference in
ddt_phys_decref().

While this should never happen it has been observed on various
platforms.  The result is that unless your willing to patch the
ZFS code the pool is inaccessible.  Therefore, we're choosing
to more gracefully handle this case rather than leave it fatal.

http://mail.opensolaris.org/pipermail/zfs-discuss/2012-February/050972.html

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1308
2013-03-19 13:01:01 -07:00
Eric Dillmann
9759c60f1a Illumos #3035 LZ4 compression support in ZFS and GRUB
3035 LZ4 compression support in ZFS and GRUB

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Christopher Siden <csiden@delphix.com>

References:
  illumos/illumos-gate@a6f561b4ae
  https://www.illumos.org/issues/3035
  http://wiki.illumos.org/display/illumos/LZ4+Compression+In+ZFS

This patch has been slightly modified from the upstream Illumos
version to be compatible with Linux.  Due to the very limited
stack space in the kernel a lz4 workspace kmem cache is used.
Since we are using gcc we are also able to take advantage of the
gcc optimized __builtin_ctz functions.

Support for GRUB has been dropped from this patch.  That code
is available but those changes will need to made to the upstream
GRUB package.

Lastly, several hunks of dead code were dropped for clarity.  They
include the functions real_LZ4_uncompress(), LZ4_compressBound()
and the Visual Studio specific hunks wrapped in _MSC_VER.

Ported-by: Eric Dillmann <eric@jave.fr>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1217
2013-01-29 09:28:20 -08:00
Brian Behlendorf
4cec9b2dc7 Only reduce __zio_execute() stack usage in kernel space
Related to 91579709fc we need to
be very careful about not overrunning the stack in kernel space.
However, in user space we're already allowing slightly larger
stacks so this stack usage optimization is not required there.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-09 10:34:35 -08:00
Brian Behlendorf
91579709fc Fix __zio_execute() asynchronous dispatch
To save valuable stack all zio's were made asynchronous when in the
tgx_sync_thread context or during pool initialization.  See commit
2fac4c2 for the original patch and motivation.

Unfortuantely, the changes to dsl_pool_sync_context() made by the
feature flags broke this logic causing in __zio_execute() to dispatch
itself infinitely when called during pool initialization.  This
commit refines the existing logic to specificly target only the two
cases we care about.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2013-01-08 10:35:43 -08:00