Commit Graph

293 Commits

Author SHA1 Message Date
Alek P
dcec0a12c8 port async unlinked drain from illumos-nexenta
This patch is an async implementation of the existing sync
zfs_unlinked_drain() function. This function is called at mount time and
is responsible for freeing znodes that we didn't get to freeing before.
We don't have to hold mounting of the dataset until the unlinked list is
fully drained as is done now. Since we can process the unlinked set
asynchronously this results in a better user experience when mounting a
dataset with entries in the unlinked set.

Reviewed by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes #8142
2019-02-12 10:41:15 -08:00
Serapheim Dimitropoulos
c853f382db Change target size of metaslabs from 256GB to 16GB
= Old behavior

For vdev sizes 100GB to 50TB we keep ~200 metaslabs per
vdev and the metaslab size grows from 512MB to 256GB.
For vdev's bigger than that we start increasing the
number of metaslabs until we hit the 128K limit.

= New Behavior

For vdev sizes 100GB to 3TB we keep ~200 metaslabs per
vdev and the metaslab size grows from 512MB to 16GB.
For vdev's bigger than that we start increasing the
number of metaslabs until we hit the 128K limit.

= Reasoning

The old behavior makes metaslabs grow in size when
the vdev range is between 3TB (ms_size 16GB) and
32PB (ms_size 256GB). Even though keeping the number
of metaslabs is good in terms of potential number of
I/Os per TXG, these bigger metaslabs take longer
to be loaded and after they are loaded they can
take up a lot of memory because of their range trees.

This change tries to put a boundary in memory and
loading time for the specific range of vdev sizes.

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8324
2019-01-25 16:38:27 -08:00
Brian Behlendorf
64bdf63f5c
ztest: split block reconstruction
Increase the default allowed number of reconstruction attempts.
There's not an exact right number for this setting.  It needs
to be set large enough to cover any realistic failure scenarios
and small enough to avoid stalling the IO pipeline and invoking
the dead man detection.

The current value of 256 was empirically determined to be too
low based on multi-day runs of ztest.  The fault injection code
would inject more damage than could be reconstructed given the
relatively small number of attempts.  However, in all observed
cases the block could be reconstructed using a slightly higher
limit.

Based on local testing increasing the default value to 4096 was
determined to strike the best balance.  Checking all combinations
takes less than 10s in the worst case, and has so far eliminated
the vast majority of false positives detected by ztest.  This
delay is roughly on par with how long retries may be performed
to a misbehaving HDD and was deemed to be reasonable.  Better to
err on the side of a brief delay rather than fail to reconstruct
the data.

Lastly, the -Y flag has been added to zdb to make it easy to try all
possible combinations when performing split block reconstruction.
For badly damaged blocks with 18 splits, they can be fully enumerated
within a few minutes.  This has been done to ensure permanent errors
are never incorrectly reported when ztest verifies the pool with zdb.

Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8271
2019-01-16 14:10:02 -08:00
Brian Behlendorf
6e91a72fe3
Disable 'zfs remap' command
The implementation of 'zfs remap' has proven to be problematic since
it modifies the objset (but not its logical contents) by dirtying
metadata without owning it.  The consequence of which is that
dmu_objset_remap_indirects() is vulnerable to certain races.

For example, if we are in the middle of receiving into the filesystem
while it is being remapped.  Then it is possible we could evict the
objset when the receive completes (see dsl_dataset_clone_swap_sync_impl,
or dmu_recv_end_sync), but dmu_objset_remap_indirects() may be still
using the objset.  The result of which would be a panic.

Extended runs of ztest(8) have exposed other possible races which
can occur when using 'zfs remap'.  Several of these have been fixed
but there may be others which have not yet been encountered and
diagnosed.

Furthermore, the ability to manually remap a filesystem is no longer
particularly useful now that the removal code can map large chunks.
Coupled with the fact that explaining what this command does and why
it may be useful requires a detailed understanding of the internals
of device removal.  These are details users should not be bothered
with.

Therefore, the 'zfs remap' command is being disabled but not entirely
removed.  It may be removed in the future or potentially reworked
to address the issues described above.  Since 'zfs remap' has never
been part of a tagged release its removal is expected to have
minimal impact.

The ZTS tests have been updated to continue to exercise the command
to prevent atrophy, but it has been removed entirely from ztest(8).

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8238
2019-01-15 15:46:58 -08:00
George Wilson
619f097693 OpenZFS 9102 - zfs should be able to initialize storage devices
PROBLEM
========

The first access to a block incurs a performance penalty on some platforms
(e.g. AWS's EBS, VMware VMDKs). Therefore we recommend that volumes are
"thick provisioned", where supported by the platform (VMware). This can
create a large delay in getting a new virtual machines up and running (or
adding storage to an existing Engine). If the thick provision step is
omitted, write performance will be suboptimal until all blocks on the LUN
have been written.

SOLUTION
=========

This feature introduces a way to 'initialize' the disks at install or in the
background to make sure we don't incur this first read penalty.

When an entire LUN is added to ZFS, we make all space available immediately,
and allow ZFS to find unallocated space and zero it out. This works with
concurrent writes to arbitrary offsets, ensuring that we don't zero out
something that has been (or is in the middle of being) written. This scheme
can also be applied to existing pools (affecting only free regions on the
vdev). Detailed design:
        - new subcommand:zpool initialize [-cs] <pool> [<vdev> ...]
                - start, suspend, or cancel initialization
        - Creates new open-context thread for each vdev
        - Thread iterates through all metaslabs in this vdev
        - Each metaslab:
                - select a metaslab
                - load the metaslab
                - mark the metaslab as being zeroed
                - walk all free ranges within that metaslab and translate
                  them to ranges on the leaf vdev
                - issue a "zeroing" I/O on the leaf vdev that corresponds to
                  a free range on the metaslab we're working on
                - continue until all free ranges for this metaslab have been
                  "zeroed"
                - reset/unmark the metaslab being zeroed
                - if more metaslabs exist, then repeat above tasks.
                - if no more metaslabs, then we're done.

        - progress for the initialization is stored on-disk in the vdev’s
          leaf zap object. The following information is stored:
                - the last offset that has been initialized
                - the state of the initialization process (i.e. active,
                  suspended, or canceled)
                - the start time for the initialization

        - progress is reported via the zpool status command and shows
          information for each of the vdevs that are initializing

Porting notes:
- Added zfs_initialize_value module parameter to set the pattern
  written by "zpool initialize".
- Added zfs_vdev_{initializing,removal}_{min,max}_active module options.

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Wren Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: loli10K <ezomori.nozomu@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Signed-off-by: Tim Chase <tim@chase2k.com>
Ported-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://www.illumos.org/issues/9102
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c3963210eb
Closes #8230
2019-01-07 10:37:26 -08:00
Tony Hutter
c66401fae0 Add enclosure_symlinks option to vdev_id
Add an 'enclosure_symlinks' option to vdev_id.conf.  This creates
consistently named symlinks to the enclosure devices (/dev/sg*) based
off the configuration in vdev_id.conf.  The enclosure symlinks show
up in /dev/by-enclosure/<prefix>-<channel><num>.  The links make it
make it easy to run sg_ses on a particular enclosure device.  The
enclosure links are created in addition to the normal
/dev/disk/by-vdev links.

'enclosure_symlinks' is only valid in sas_direct configurations.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Simon Guest <simon.guest@tesujimath.org>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #8194
2018-12-14 17:27:49 -08:00
Prakash Surya
53b1f5eac6 OpenZFS 9963 - Separate tunable for disabling ZIL vdev flush
Porting Notes:
* Add options to zfs-module-parameters(5) man page.
* zfs_nocacheflush move to vdev.c instead of vdev_disk.c, since
  the latter doesn't get built for user space.

Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: George Melikov <mail@gmelikov.ru>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9963
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f8fdf68125
Closes #8186
2018-12-07 11:06:29 -08:00
Brian Behlendorf
7c9a42921e
Detect IO errors during device removal
* Detect IO errors during device removal

While device removal cannot verify the checksums of individual
blocks during device removal, it can reasonably detect hard IO
errors from the leaf vdevs.  Failure to perform this error
checking can result in device removal completing successfully,
but moving no data which will permanently corrupt the pool.

Situation 1: faulted/degraded vdevs

In the configuration shown below, the removal of mirror-0 will
permanently corrupt the pool.  Device removal will preferentially
copy data from 'vdev1 -> vdev3' and from 'vdev2 -> vdev4'.  Which
in this case will result in nothing being copied since one vdev
in each of those groups in unavailable.  However, device removal
will complete successfully since all IO errors are ignored.

  tank                DEGRADED     0     0     0
    mirror-0          DEGRADED     0     0     0
      /var/tmp/vdev1  FAULTED      0     0     0  external fault
      /var/tmp/vdev2  ONLINE       0     0     0
    mirror-1          DEGRADED     0     0     0
      /var/tmp/vdev3  ONLINE       0     0     0
      /var/tmp/vdev4  FAULTED      0     0     0  external fault

This issue is resolved by updating the source child selection
logic to exclude unreadable leaf vdevs.  Additionally, unwritable
destination child vdevs which can never succeed are skipped to
prevent generating a large number of write IO errors.

Situation 2: individual hard IO errors

During removal if an unexpected hard IO error is encountered when
either reading or writing the child vdev the entire removal
operation is cancelled.  While it may be possible to reconstruct
the data after removal that cannot be guaranteed.  The only
strictly safe thing to do is to cancel the removal.

As a future improvement we may want to instead suspend the removal
process and allow the damaged region to be retried.  But that work
is left for another time, hard IO errors during the removal process
are expected to be exceptionally rare.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #6900
Closes #8161
2018-12-04 09:37:37 -08:00
Rich Ercolani
62ee31adce Fix typo in update to zfs-module-parameters(5)
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: bunder2015 <omfgbunder@gmail.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #8153
2018-11-26 10:23:58 -08:00
Tony Hutter
ad796b8a3b Add zpool status -s (slow I/Os) and -p (parseable)
This patch adds a new slow I/Os (-s) column to zpool status to show the
number of VDEV slow I/Os. This is the number of I/Os that didn't
complete in zio_slow_io_ms milliseconds. It also adds a new parsable
(-p) flag to display exact values.

 	NAME         STATE     READ WRITE CKSUM  SLOW
 	testpool     ONLINE       0     0     0     -
	  mirror-0   ONLINE       0     0     0     -
 	    loop0    ONLINE       0     0     0    20
 	    loop1    ONLINE       0     0     0     0

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #7756
Closes #6885
2018-11-08 16:47:24 -08:00
Richard Elling
6644e5bb6e Update zfs-events.5 with info from PSARC 2009/497
Update zfs-events.5 with info from PSARC 2009/497 regarding ereport fields.
Also updates ZIO_STAGE_* and ZIO_FLAG_* descriptions to match current source.

Reviewed by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #8057
2018-11-01 15:54:55 -07:00
Tom Caputi
80a91e7469 Defer new resilvers until the current one ends
Currently, if a resilver is triggered for any reason while an
existing one is running, zfs will immediately restart the existing
resilver from the beginning to include the new drive. This causes
problems for system administrators when a drive fails while another
is already resilvering. In this case, the optimal thing to do to
reduce risk of data loss is to wait for the current resilver to end
before immediately replacing the second failed drive, which allows
the system to operate with two incomplete drives for the minimum
amount of time.

This patch introduces the resilver_defer feature that essentially
does this for the admin without forcing them to wait and monitor
the resilver manually. The change requires an on-disk feature
since we must mark drives that are part of a deferred resilver in
the vdev config to ensure that we do not assume they are done
resilvering when an existing resilver completes.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: @mmaybee 
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7732
2018-10-18 21:06:18 -07:00
Matthew Ahrens
dfbe267503 OpenZFS 9617 - too-frequent TXG sync causes excessive write inflation
Porting notes:
* Renamed zfs_dirty_data_sync_pct to zfs_dirty_data_sync_percent and
  changed the type to be consistent with the other dirty module params.
* Updated zfs-module-parameters.5 accordingly.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9617
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7928f4ba
Closes #7976
2018-10-04 13:13:28 -07:00
Brian Behlendorf
1258bd778e
Refine split block reconstruction
Due to a flaw in 4589f3ae the number of unique combinations
could be calculated incorrectly.  This could result in the
random combinations reconstruction being used when it would
have been possible to check all combinations.

This change fixes the unique combinations calculation and
simplifies the reconstruction logic by maintaining a per-
segment list of unique copies.

The vdev_indirect_splits_damage() function was introduced
to validate both the enumeration and random reconstruction
logic with ztest.  It is implemented such it will never
make a known recoverable block unrecoverable.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #6900 
Closes #7934
2018-10-01 10:36:34 -07:00
DeHackEd
81155b296d Fix allocation_classes GUID in zpool-features(5)
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: DHE <git@dehacked.net>
Closes #7920
2018-09-18 08:59:47 -07:00
Don Brady
cc99f275a2 Pool allocation classes
Allocation Classes add the ability to have allocation classes in a
pool that are dedicated to serving specific block categories, such
as DDT data, metadata, and small file blocks. A pool can opt-in to
this feature by adding a 'special' or 'dedup' top-level VDEV.

Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Reviewed-by: Andreas Dilger <andreas.dilger@chamcloud.com>
Reviewed-by: DHE <git@dehacked.net>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Gregor Kopka <gregor@kopka.net>
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #5182
2018-09-05 18:33:36 -07:00
Tom Caputi
c3bd3fb4ac OpenZFS 9403 - assertion failed in arc_buf_destroy()
Assertion failed in arc_buf_destroy() when concurrently reading
block with checksum error.

Porting notes:
* The ability to zinject decompression errors has been added, but
  this only works at the zio_decompress() level, where we have all
  of the info we need to match against the user's zinject options.
* The decompress_fault test has been added to test the new zinject
  functionality
* We attempted to set zio_decompress_fail_fraction to (1 << 18) in
  ztest for further test coverage. Although this did uncover a few
  low priority issues, this unfortuantely also causes ztest to
  ASSERT in many locations where the code is working correctly since
  it is designed to fail on IO errors. Developers can manually set
  this variable with the '-o' option to find and debug issues.

Authored by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Matt Ahrens <mahrens@delphix.com>
Ported-by: Tom Caputi <tcaputi@datto.com>

OpenZFS-issue: https://illumos.org/issues/9403
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/fa98e487a9
Closes #7822
2018-08-29 11:33:33 -07:00
Toomas Soome
5fadb7fb0c OpenZFS 8906 - uts: illumos rootfs should support salted cksum
Porting notes:
* As of grub-2.02 these checksums are not supported.  However, as
  pointed out in #6501 there are alternatives such as EFISTUB which
  work and have no such restriction.  A warning was added to the
  checksum property section of the zfs.8 man page.

Authored by: Toomas Soome <tsoome@me.com>
Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/8906
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7dec52f
Closes #6501
Closes #7714
2018-07-27 08:35:28 -07:00
Matthew Ahrens
2e5dc449c1 OpenZFS 9337 - zfs get all is slow due to uncached metadata
This project's goal is to make read-heavy channel programs and zfs(1m)
administrative commands faster by caching all the metadata that they will
need in the dbuf layer. This will prevent the data from being evicted, so
that any future call to i.e. zfs get all won't have to go to disk (very
much). There are two parts:

The dbuf_metadata_cache. We identify what to put into the cache based on
the object type of each dbuf.  Caching objset properties os
{version,normalization,utf8only,casesensitivity} in the objset_t. The reason
these needed to be cached is that although they are queried frequently,
they aren't stored in a dbuf type which we can easily recognize and cache in
the dbuf layer; instead, we have to explicitly store them. There's already
existing infrastructure for maintaining cached properties in the objset
setup code, so I simply used that.

Performance Testing:

 - Disabled kmem_flags
 - Tuned dbuf_cache_max_bytes very low (128K)
 - Tuned zfs_arc_max very low (64M)

Created test pool with 400 filesystems, and 100 snapshots per filesystem.
Later on in testing, added 600 more filesystems (with no snapshots) to make
sure scaling didn't look different between snapshots and filesystems.

Results:

    | Test                   | Time (trunk / diff) | I/Os (trunk / diff) |
    +------------------------+---------------------+---------------------+
    | zpool import           |     0:05 / 0:06     |    12.9k / 12.9k    |
    | zfs get all (uncached) |     1:36 / 0:53     |    16.7k / 5.7k     |
    | zfs get all (cached)   |     1:36 / 0:51     |    16.0k / 6.0k     |

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Thomas Caputi <tcaputi@datto.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Alek Pinchuk <apinchuk@datto.com>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>

OpenZFS-issue: https://illumos.org/issues/9337
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7dec52f
Closes #7668
2018-07-12 10:49:27 -07:00
Don Brady
e4e94ca315 OpenZFS 9426 - metaslab size can exceed offset addressable by spacemap
Authored by: Don Brady <don.brady@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@joyent.com>

OpenZFS-issue: https://www.illumos.org/issues/9426
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f1c88afb1
Closes #7700
2018-07-11 15:55:48 -07:00
Serapheim Dimitropoulos
a7ed98d8b5 OpenZFS 9330 - stack overflow when creating a deeply nested dataset
Datasets that are deeply nested (~100 levels) are impractical. We just
put a limit of 50 levels to newly created datasets. Existing datasets
should work without a problem.

The problem can be seen by attempting to create a dataset using the -p
option with many levels:

    panic[cpu0]/thread=ffffff01cd282c20: BAD TRAP: type=8 (#df Double fault) rp=ffffffff

    fffffffffbc3aa60 unix:die+100 ()
    fffffffffbc3ab70 unix:trap+157d ()
    ffffff00083d7020 unix:_patch_xrstorq_rbx+196 ()
    ffffff00083d7050 zfs:dbuf_rele+2e ()
    ...
    ffffff00083d7080 zfs:dsl_dir_close+32 ()
    ffffff00083d70b0 zfs:dsl_dir_evict+30 ()
    ffffff00083d70d0 zfs:dbuf_evict_user+4a ()
    ffffff00083d7100 zfs:dbuf_rele_and_unlock+87 ()
    ffffff00083d7130 zfs:dbuf_rele+2e ()
    ... The block above repeats once per directory in the ...
    ... create -p command, working towards the root ...
    ffffff00083db9f0 zfs:dsl_dataset_drop_ref+19 ()
    ffffff00083dba20 zfs:dsl_dataset_rele+42 ()
    ffffff00083dba70 zfs:dmu_objset_prefetch+e4 ()
    ffffff00083dbaa0 zfs:findfunc+23 ()
    ffffff00083dbb80 zfs:dmu_objset_find_spa+38c ()
    ffffff00083dbbc0 zfs:dmu_objset_find+40 ()
    ffffff00083dbc20 zfs:zfs_ioc_snapshot_list_next+4b ()
    ffffff00083dbcc0 zfs:zfsdev_ioctl+347 ()
    ffffff00083dbd00 genunix:cdev_ioctl+45 ()
    ffffff00083dbd40 specfs:spec_ioctl+5a ()
    ffffff00083dbdc0 genunix:fop_ioctl+7b ()
    ffffff00083dbec0 genunix:ioctl+18e ()
    ffffff00083dbf10 unix:brand_sys_sysenter+1c9 ()

Porting notes:
* Added zfs_max_dataset_nesting module option with documentation.
* Updated zfs_rename_014_neg.ksh for Linux.
* Increase the zfs.sh stack warning to 15K.  Enough time has passed
  that 16K can be reasonably assumed to be the default value.  It
  was increased in the 3.15 kernel released in June of 2014.

Authored by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>

OpenZFS-issue: https://www.illumos.org/issues/9330
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/757a75a
Closes #7681
2018-07-09 13:02:50 -07:00
Serapheim Dimitropoulos
4d044c4c1d OpenZFS 9238 - ZFS Spacemap Encoding V2
Motivation
==========

The current space map encoding has the following disadvantages:
[1] Assuming 512 sector size each entry can represent at most 16MB for a segment.
    This makes the encoding very inefficient for large regions of space.
[2] As vdev-wide space maps have started to be used by new features (i.e.
    device removal, zpool checkpoint) we've started imposing limits in the
    vdevs that can be used with them based on the maximum addressable offset
    (currently 64PB for a top-level vdev).

New encoding
============

The layout can be found at space_map.h and it remains backwards compatible with
the old one. The introduced two-word entry format, besides extending the limits
imposed by the single-entry layout, also includes a vdev field and some extra
padding after its prefix.

The extra padding after the prefix should is reserved for future usage (e.g.
new prefixes for future encodings or new fields for flags). The new vdev field
not only makes the space maps more self-descriptive, but also opens the doors
for pool-wide space maps (expected to be used in the log spacemap project).

One final important note is that the number of bits used for vdevs is reduced
to 24 bits for blkptrs. That was decided as we don't know of any setups that
use more than 16M vdevs for the time being and we wanted to fit the vdev field
in the space map. In addition that gives us some extra bits in dva_t.

Other references:
=================

The new encoding is also discussed towards the end of the Log Space Map
presentation from 2017's OpenZFS summit.
Link: https://www.youtube.com/watch?v=jj2IxRkl5bQ

Authored by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <gwilson@zfsmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-commit: https://github.com/openzfs/openzfs/commit/90a56e6d
OpenZFS-issue: https://www.illumos.org/issues/9238
Closes #7665
2018-07-05 12:02:34 -07:00
Tim Chase
3be1eb29da Fix formatting in zpool-features(5)
The formatting of the features beginning with large_blocks was broken
when the zpool_checkpoint feature was added.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7658
2018-06-27 09:34:25 -07:00
Serapheim Dimitropoulos
d2734cce68 OpenZFS 9166 - zfs storage pool checkpoint
Details about the motivation of this feature and its usage can
be found in this blogpost:

    https://sdimitro.github.io/post/zpool-checkpoint/

A lightning talk of this feature can be found here:
https://www.youtube.com/watch?v=fPQA8K40jAM

Implementation details can be found in big block comment of
spa_checkpoint.c

Side-changes that are relevant to this commit but not explained
elsewhere:

* renames members of "struct metaslab trees to be shorter without
  losing meaning

* space_map_{alloc,truncate}() accept a block size as a
  parameter. The reason is that in the current state all space
  maps that we allocate through the DMU use a global tunable
  (space_map_blksz) which defauls to 4KB. This is ok for metaslab
  space maps in terms of bandwirdth since they are scattered all
  over the disk. But for other space maps this default is probably
  not what we want. Examples are device removal's vdev_obsolete_sm
  or vdev_chedkpoint_sm from this review. Both of these have a
  1:1 relationship with each vdev and could benefit from a bigger
  block size.

Porting notes:

* The part of dsl_scan_sync() which handles async destroys has
  been moved into the new dsl_process_async_destroys() function.

* Remove "VERIFY(!(flags & FWRITE))" in "kernel.c" so zhack can write
  to block device backed pools.

* ZTS:
  * Fix get_txg() in zpool_sync_001_pos due to "checkpoint_txg".

  * Don't use large dd block sizes on /dev/urandom under Linux in
    checkpoint_capacity.

  * Adopt Delphix-OS's setting of 4 (spa_asize_inflation =
    SPA_DVAS_PER_BP + 1) for the checkpoint_capacity test to speed
    its attempts to fill the pool

  * Create the base and nested pools with sync=disabled to speed up
    the "setup" phase.

  * Clear labels in test pool between checkpoint tests to avoid
    duplicate pool issues.

  * The import_rewind_device_replaced test has been marked as "known
    to fail" for the reasons listed in its DISCLAIMER.

  * New module parameters:

      zfs_spa_discard_memory_limit,
      zfs_remove_max_bytes_pause (not documented - debugging only)
      vdev_max_ms_count (formerly metaslabs_per_vdev)
      vdev_min_ms_count

Authored by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9166
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7159fdb8
Closes #7570
2018-06-26 10:07:42 -07:00
ajs124
a8577bdb32 Fix duplicate "fB" typo
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: bunder2015 <omfgbunder@gmail.com>
Signed-off-by: ajs124 <git@ajs124.de>
Closes #7649
2018-06-25 09:50:01 -07:00
John Gallagher
917f475fba Add tunables for channel programs
This patch adds tunables for modifying the maximum memory limit and
maximum instruction limit that can be specified when running a channel
program.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov
Reviewed-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
External-issue: LX-1085
Closes #7618
2018-06-15 15:10:42 -07:00
Brian Behlendorf
93ce2b4ca5 Update build system and packaging
Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.

Build system and packaging:
  * Renamed SPL_* autoconf m4 macros to ZFS_*.
  * Removed redundant SPL_* autoconf m4 macros.
  * Updated the RPM spec files to remove SPL package dependency.
  * The zfs package obsoletes the spl package, and the zfs-kmod
    package obsoletes the spl-kmod package.
  * The zfs-kmod-devel* packages were updated to add compatibility
    symlinks under /usr/src/spl-x.y.z until all dependent packages
    can be updated.  They will be removed in a future release.
  * Updated copy-builtin script for in-kernel builds.
  * Updated DKMS package to include the spl.ko.
  * Updated stale AUTHORS file to include all contributors.
  * Updated stale COPYRIGHT and included the SPL as an exception.
  * Renamed README.markdown to README.md
  * Renamed OPENSOLARIS.LICENSE to LICENSE.
  * Renamed DISCLAIMER to NOTICE.

Required code changes:
  * Removed redundant HAVE_SPL macro.
  * Removed _BOOT from nvpairs since it doesn't apply for Linux.
  * Initial header cleanup (removal of empty headers, refactoring).
  * Remove SPL repository clone/build from zimport.sh.
  * Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
    to build issues when forcing C99 compilation.
  * Replaced legacy ACCESS_ONCE with READ_ONCE.
  * Include needed headers for `current` and `EXPORT_SYMBOL`.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes #7556
2018-05-29 16:00:33 -07:00
Brian Behlendorf
1272941f49 Merge branch 'zfsonlinux/merge-spl'
Merge a minimal version of the zfsonlinux/spl repository in to the
zfsonlinux/zfs repository.  Care was taken to prevent file conflicts
when merging and to preserve the spl repository history.  The spl
kernel module remains under the GPLv2 license as documented by the
additional THIRDPARTYLICENSE.gplv2 file.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2018-05-29 14:57:55 -07:00
Brian Behlendorf
a91258913f Prepare SPL repo to merge with ZFS repo
This commit removes everything from the repository except the core
SPL implementation for Linux.  Those files which remain have been
moved to non-conflicting locations to facilitate the merge.
The README.md and associated files have been updated accordingly.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2018-05-29 14:51:39 -07:00
Matthew Ahrens
0dc2f70c5c OpenZFS 9486 - reduce memory used by device removal on fragmented pools
Device removal allocates a new location for each allocated segment on
the disk that's being removed.  Each allocation results in one entry in
the mapping table, which maps from old location + length to new
location.  When a fragmented disk is removed, this can result in a large
number of mapping entries, and thus a large amount of memory consumed by
the mapping table.  In the worst real-world cases, we've seen around 1GB
of RAM per 1TB of storage removed.

We can improve on this situation by allocating larger segments, which
span across both allocated and free regions of the device being removed.
By including free regions in the allocation (and thus mapping), we
reduce the number of mapping entries.  For example, if we have a 4K
allocation followed by 1K free and then 4K allocated, we would allocate
4+1+4 = 9KB, and then move the entire region (including allocated and
free parts).  In this case we used one mapping where previously we would
have used two, but often the ratio is much higher (up to 20:1 in
real-world use).  We then need to mark the regions that were free on the
removing device as free in the new locations, and also obsolete in the
mapping entry.

This method preserves the fragmentation of the removing device, rather
than consolidating its allocated space into a small number of chunks
where possible.  But it results in drastic reduction of memory used by
the mapping table - around 20x in the most-fragmented cases.

In the most fragmented real-world cases, this reduces memory used by the
mapping from ~1GB to ~50MB of RAM per 1TB of storage removed.  Less
fragmented cases will typically also see around 50-100MB of RAM per 1TB
of storage.

Porting notes:

* Add the following as module parameters:
    * zfs_condense_indirect_vdevs_enable
    * zfs_condense_max_obsolete_bytes

* Document the following module parameters:
   * zfs_condense_indirect_vdevs_enable
   * zfs_condense_max_obsolete_bytes
   * zfs_condense_min_mapping_bytes

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9486
OpenZFS-commit: https://github.com/ahrens/illumos/commit/07152e142e44c
External-issue: DLPX-57962
Closes #7536
2018-05-24 10:18:07 -07:00
Pavel Zakharov
6cb8e5306d OpenZFS 9075 - Improve ZFS pool import/load process and corrupted pool recovery
Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:

	7638 Refactor spa_load_impl into several functions
	8961 SPA load/import should tell us why it failed
	7277 zdb should be able to print zfs_dbgmsg's

To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.

The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.

The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.

When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.

This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.

With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
of data, this feature is for now restricted to a read-only import.

Porting notes (ZTS):
* Fix 'make dist' target in zpool_import

* The maximum path length allowed by tar is 99 characters.  Several
  of the new test cases exceeded this limit resulting in them not
  being included in the tarball.  Shorten the names slightly.

* Set/get tunables using accessor functions.

* Get last synced txg via the "zfs_txg_history" mechanism.

* Clear zinject handlers in cleanup for import_cache_device_replaced
  and import_rewind_device_replaced in order that the zpool can be
  exported if there is an error.

* Increase FILESIZE to 8G in zfs-test.sh to allow for a larger
  ext4 file system to be created on ZFS_DISK2.  Also, there's
  no need to partition ZFS_DISK2 at all.  The partitioning had
  already been disabled for multipath devices.  Among other things,
  the partitioning steals some space from the ext4 file system,
  makes it difficult to accurately calculate the paramters to
  parted and can make some of the tests fail.

* Increase FS_SIZE and FILE_SIZE in the zpool_import test
  configuration now that FILESIZE is larger.

* Write more data in order that device evacuation take lonnger in
  a couple tests.

* Use mkdir -p to avoid errors when the directory already exists.

* Remove use of sudo in import_rewind_config_changed.

Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9075
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/619c0123
Closes #7459
2018-05-08 21:35:27 -07:00
Paul Dagnelie
ca0845d59e OpenZFS 9256 - zfs send space estimation off by > 10% on some datasets
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

Porting Notes:
* Added tuning to man page.
* Test case changes dropped, default behavior unchanged.

OpenZFS-issue: https://www.illumos.org/issues/9256
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/32356b3c56
Closes #7470
2018-05-08 08:59:24 -07:00
Matthew Ahrens
964c2d69a9 OpenZFS 9236 - nuke spa_dbgmsg
We should use zfs_dbgmsg instead of spa_dbgmsg. Or at least,
metaslab_condense() should call zfs_dbgmsg because it's important and
rare enough to always log. It's possible that the message in
zio_dva_allocate() would be too high-frequency for zfs_dbgmsg.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

Patch Notes:
* Removed ZFS_DEBUG_SPA from zfs-module-parameters.5

OpenZFS-issue: https://www.illumos.org/issues/9236
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/cfaba7f668
Closes #7467
2018-04-30 10:19:48 -07:00
Matt Ahrens
d830d4795a OpenZFS 9280 - Assertion failure while running removal_with_ganging test with 4K devices
Authored by: Matt Ahrens <Matt.Ahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9280
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/243952c
Closes #7445
2018-04-17 10:44:50 -07:00
Brian Behlendorf
4589f3ae4c Optimize possible split block search space
Remove duplicate segment copies to minimize the possible search
space for reconstruction.  Once reduced an accurate assessment can
be made regarding the difficulty in reconstructing the block.

Also, ztest will now run zdb with
zfs_reconstruct_indirect_combinations_max set to 1000000 in an attempt
to avoid checksum errors.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6900
2018-04-14 12:22:43 -07:00
Matthew Ahrens
9e052db462 OpenZFS 9290 - device removal reduces redundancy of mirrors
Mirrors are supposed to provide redundancy in the face of whole-disk
failure and silent damage (e.g. some data on disk is not right, but ZFS
hasn't detected the whole device as being broken). However, the current
device removal implementation bypasses some of the mirror's redundancy.
Note that in no case is incorrect data returned, but we might get a
checksum error when we should have been able to find the right data.

There are two underlying problems:

1. When we remove a mirror device, we only read one side of the mirror.
Since we can't verify the checksum, this side may be silently bad, but
the good data is on the other side of the mirror (which we didn't read).
This can cause the removal to "bake in" the busted data – all copies of
the data in the new location are the same, busted version, while we left
the good version behind.

The fix for this is to read and copy both sides of the mirror. If the
old and new vdevs are mirrors, we will read both sides of the old
mirror, and write each copy to the corresponding side of the new mirror.
(If the old and new vdevs have a different number of children, we will
do this as best as possible.) Even though we aren't verifying checksums,
this ensures that as long as there's a good copy of the data, we'll have
a good copy after the removal, even if there's silent damage to one side
of the mirror. If we're removing a mirror that has some silent damage,
we'll have exactly the same damage in the new location (assuming that
the new location is also a mirror).

2. When we read from an indirect vdev that points to a mirror vdev, we
only consider one copy of the data. This can lead to reduced effective
redundancy, because we might read a bad copy of the data from one side
of the mirror, and not retry the other, good side of the mirror.

Note that the problem is not with the removal process, but rather after
the removal has completed (having copied correct data to both sides of
the mirror), if one side of the new mirror is silently damaged, we
encounter the problem when reading the relocated data via the indirect
vdev. Also note that the problem doesn't occur when ZFS knows that one
side of the mirror is bad, e.g. when a disk entirely fails or is
offlined.

The impact is that reads (from indirect vdevs that point to mirrors) may
return a checksum error even though the good data exists on one side of
the mirror, and scrub doesn't repair all data on the mirror (if some of
it is pointed to via an indirect vdev).

The fix for this is complicated by "split blocks" - one logical block
may be split into two (or more) pieces with each piece moved to a
different new location. In this case we need to read all versions of
each split (one from each side of the mirror), and figure out which
combination of versions results in the correct checksum, and then repair
the incorrect versions.

This ensures that we supply the same redundancy whether you use device
removal or not. For example, if a mirror has small silent errors on all
of its children, we can still reconstruct the correct data, as long as
those errors are at sufficiently-separated offsets (specifically,
separated by the largest block size - default of 128KB, but up to 16MB).

Porting notes:

* A new indirect vdev check was moved from dsl_scan_needs_resilver_cb()
  to dsl_scan_needs_resilver(), which was added to ZoL as part of the
  sequential scrub work.

* Passed NULL for zfs_ereport_post_checksum()'s zbookmark_phys_t
  parameter.  The extra parameter is unique to ZoL.

* When posting indirect checksum errors the ABD can be passed directly,
  zfs_ereport_post_checksum() is not yet ABD-aware in OpenZFS.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9290
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/591
Closes #6900
2018-04-14 12:21:39 -07:00
Matthew Ahrens
a1d477c24c OpenZFS 7614, 9064 - zfs device evacuation/removal
OpenZFS 7614 - zfs device evacuation/removal
OpenZFS 9064 - remove_mirror should wait for device removal to complete

This project allows top-level vdevs to be removed from the storage pool
with "zpool remove", reducing the total amount of storage in the pool.
This operation copies all allocated regions of the device to be removed
onto other devices, recording the mapping from old to new location.
After the removal is complete, read and free operations to the removed
(now "indirect") vdev must be remapped and performed at the new location
on disk.  The indirect mapping table is kept in memory whenever the pool
is loaded, so there is minimal performance overhead when doing operations
on the indirect vdev.

The size of the in-memory mapping table will be reduced when its entries
become "obsolete" because they are no longer used by any block pointers
in the pool.  An entry becomes obsolete when all the blocks that use
it are freed.  An entry can also become obsolete when all the snapshots
that reference it are deleted, and the block pointers that reference it
have been "remapped" in all filesystems/zvols (and clones).  Whenever an
indirect block is written, all the block pointers in it will be "remapped"
to their new (concrete) locations if possible.  This process can be
accelerated by using the "zfs remap" command to proactively rewrite all
indirect blocks that reference indirect (removed) vdevs.

Note that when a device is removed, we do not verify the checksum of
the data that is copied.  This makes the process much faster, but if it
were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be
possible to copy the wrong data, when we have the correct data on e.g.
the other side of the mirror.

At the moment, only mirrors and simple top-level vdevs can be removed
and no removal is allowed if any of the top-level vdevs are raidz.

Porting Notes:

* Avoid zero-sized kmem_alloc() in vdev_compact_children().

    The device evacuation code adds a dependency that
    vdev_compact_children() be able to properly empty the vdev_child
    array by setting it to NULL and zeroing vdev_children.  Under Linux,
    kmem_alloc() and related functions return a sentinel pointer rather
    than NULL for zero-sized allocations.

* Remove comment regarding "mpt" driver where zfs_remove_max_segment
  is initialized to SPA_MAXBLOCKSIZE.

  Change zfs_condense_indirect_commit_entry_delay_ticks to
  zfs_condense_indirect_commit_entry_delay_ms for consistency with
  most other tunables in which delays are specified in ms.

* ZTS changes:

    Use set_tunable rather than mdb
    Use zpool sync as appropriate
    Use sync_pool instead of sync
    Kill jobs during test_removal_with_operation to allow unmount/export
    Don't add non-disk names such as "mirror" or "raidz" to $DISKS
    Use $TEST_BASE_DIR instead of /tmp
    Increase HZ from 100 to 1000 which is more common on Linux

    removal_multiple_indirection.ksh
        Reduce iterations in order to not time out on the code
        coverage builders.

    removal_resume_export:
        Functionally, the test case is correct but there exists a race
        where the kernel thread hasn't been fully started yet and is
        not visible.  Wait for up to 1 second for the removal thread
        to be started before giving up on it.  Also, increase the
        amount of data copied in order that the removal not finish
        before the export has a chance to fail.

* MMP compatibility, the concept of concrete versus non-concrete devices
  has slightly changed the semantics of vdev_writeable().  Update
  mmp_random_leaf_impl() accordingly.

* Updated dbuf_remap() to handle the org.zfsonlinux:large_dnode pool
  feature which is not supported by OpenZFS.

* Added support for new vdev removal tracepoints.

* Test cases removal_with_zdb and removal_condense_export have been
  intentionally disabled.  When run manually they pass as intended,
  but when running in the automated test environment they produce
  unreliable results on the latest Fedora release.

  They may work better once the upstream pool import refectoring is
  merged into ZoL at which point they will be re-enabled.

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alex Reece <alex@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://www.illumos.org/issues/7614
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f539f1eb
Closes #6900
2018-04-14 12:16:17 -07:00
Brian Behlendorf
3b0d99289a
Fix 'zfs send/recv' hang with 16M blocks
When using 16MB blocks the send/recv queue's aren't quite big
enough.  This change leaves the default 16M queue size which a
good value for most pools.  But it additionally ensures that the
queue sizes are at least twice the allowed zfs_max_recordsize.

Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7365 
Closes #7404
2018-04-08 19:41:15 -07:00
Brian Behlendorf
de4f8d5d26
OpenZFS 9188 - increase size of dbuf cache to reduce indirect block decompression
With compressed ARC (bug 6950) we use up to 25% of our CPU to decompress
indirect blocks, under a workload of random cached reads. To reduce this
decompression cost, we would like to increase the size of the dbuf cache so
that more indirect blocks can be stored uncompressed.

If we are caching entire large files of recordsize=8K, the indirect blocks
use 1/64th as much memory as the data blocks (assuming they have the same
compression ratio). We suggest making the dbuf cache be 1/32nd of all memory,
so that in this scenario we should be able to keep all the indirect blocks
decompressed in the dbuf cache. (We want it to be more than the 1/64th that
the indirect blocks would use because we need to cache other stuff in the dbuf
cache as well.)

In real world workloads, this won't help as dramatically as the example above,
but we think it's still worth it because the risk of decreasing performance is
low. The potential negative performance impact is that we will be slightly
reducing the size of the ARC (by ~3%).

Porting Notes:
* Added modules options to zfs-module-parameters.5 man page.
* Preserved scaling based on target ARC size rather than max ARC size.

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9188
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/564
Upstream bug: DLPX-46942
Closes #7273
2018-03-13 10:52:48 -07:00
Tim Chase
02638a30ef Add zfs_scan_ignore_errors tunable
When it's set, a DTL range will be cleared even if its scan/scrub had
errors.  This allows to work around resilver/scrub upon import when the
pool has errors.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #7293
2018-03-13 10:43:14 -07:00
Tom Caputi
cf63739191 QAT support for AES-GCM
This patch adds support for acceleration of AES-GCM encryption
with Intel Quick Assist Technology.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chengfeix Zhu <chengfeix.zhu@intel.com>
Signed-off-by: Weigang Li <weigang.li@intel.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7282
2018-03-09 13:37:15 -08:00
Tony Hutter
80d52c3919 Change checksum & IO delay ratelimit values
Change checksum & IO delay ratelimit thresholds from 5/sec to 20/sec.
This allows zed to actually trigger if a bunch of these events arrive in
a short period of time (zed has a threshold of 10 events in 10 sec).
Previously, if you had, say, 100 checksum errors in 1 sec, it would get
ratelimited to 5/sec which wouldn't trigger zed to fault the drive.

Also, convert the checksum and IO delay thresholds to module params for
easy testing.

Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #7252
2018-03-04 17:34:51 -08:00
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
Nasf-Fan
9c5167d19f Project Quota on ZFS
Project quota is a new ZFS system space/object usage accounting
and enforcement mechanism. Similar as user/group quota, project
quota is another dimension of system quota. It bases on the new
object attribute - project ID.

Project ID is a numerical value to indicate to which project an
object belongs. An object only can belong to one project though
you (the object owner or privileged user) can change the object
project ID via 'chattr -p' or 'zfs project [-s] -p' explicitly.
The object also can inherit the project ID from its parent when
created if the parent has the project inherit flag (that can be
set via 'chattr +P' or 'zfs project -s [-p]').

By accounting the spaces/objects belong to the same project, we
can know how many spaces/objects used by the project. And if we
set the upper limit then we can control the spaces/objects that
are consumed by such project. It is useful when multiple groups
and users cooperate for the same project, or a user/group needs
to participate in multiple projects.

Support the following commands and functionalities:

zfs set projectquota@project
zfs set projectobjquota@project

zfs get projectquota@project
zfs get projectobjquota@project
zfs get projectused@project
zfs get projectobjused@project

zfs projectspace

zfs allow projectquota
zfs allow projectobjquota
zfs allow projectused
zfs allow projectobjused

zfs unallow projectquota
zfs unallow projectobjquota
zfs unallow projectused
zfs unallow projectobjused

chattr +/-P
chattr -p project_id
lsattr -p

This patch also supports tree quota based on the project quota via
"zfs project" commands set as following:
zfs project [-d|-r] <file|directory ...>
zfs project -C [-k] [-r] <file|directory ...>
zfs project -c [-0] [-d|-r] [-p id] <file|directory ...>
zfs project [-p id] [-r] [-s] <file|directory ...>

For "df [-i] $DIR" command, if we set INHERIT (project ID) flag on
the $DIR, then the proejct [obj]quota and [obj]used values for the
$DIR's project ID will be shown as the total/free (avail) resource.
Keep the same behavior as EXT4/XFS does.

Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by  Ned Bass <bass6@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fan Yong <fan.yong@intel.com>
TEST_ZIMPORT_POOLS="zol-0.6.1 zol-0.6.2 master"
Change-Id: Ib4f0544602e03fb61fd46a849d7ba51a6005693c
Closes #6290
2018-02-13 14:54:54 -08:00
Richard Elling
6b810d04bd Remove deprecated zfs_arc_p_aggressive_disable
zfs_arc_p_aggressive_disable is no more. This PR removes docs
and module parameters for zfs_arc_p_aggressive_disable.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Richard Elling <Richard.Elling@RichardElling.com>
Closes #7135
2018-02-07 11:54:20 -08:00
Tom Caputi
2b84817f66 Adjust ARC prefetch tunables to match docs
Currently, the ARC exposes 2 tunables (zfs_arc_min_prefetch_ms
and zfs_arc_min_prescient_prefetch_ms) which are documented
to be specified in milliseconds. However, the code actually
uses the values as though they were in seconds. This patch
adjusts the code to match the names and documentation of the
tunables.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7126
2018-02-05 16:57:53 -08:00
bunder2015
405ec516ab Fix zpool-features(5) large_block inconsistency
Large_blocks feature activation was not consistent with man page,
which erroneously stated that the feature was active when the
recordsize was increased past the stock 128KB.  It actually
becomes active when data is written to the dataset.

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: bunder2015 <omfgbunder@gmail.com>
Closes #6275 
Closes #7093
2018-01-29 15:10:32 -08:00
LOLi
63f88c12b4 Fix style issues in man pages and commands help
* Remove 'zfs snap' from zfs help message (OpenZFS sync)
* Update zfs(8) to suggest 'snap' can be used as an alias for 'snapshot'
* Enforce 80 columns limit in help messages
* Remove zfs_disable_dup_eviction from zfs-module-parameters(5)
* Expose zfs_scan_max_ext_gap as a kernel module parameter.

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #7087
2018-01-29 15:05:03 -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
Sean Eric Fagan
43cb30b3ce OpenZFS 8959 - Add notifications when a scrub is paused or resumed
Authored by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed by: Alek Pinchuk <pinchuk.alek@gmail.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

Porting Notes:
- Brought #defines in eventdefs.h in line with ZFS on Linux format.
- Updated zfs-events.5 with the new events.

OpenZFS-issue: https://www.illumos.org/issues/8959
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c862b93eea
Closes #7049
2018-01-17 10:31:00 -08:00
DeHackEd
d658b2caa9 Remove l2arc_nocompress from zfs-module-parameters(5)
Parameter was removed in d3c2ae1c08
(OpenZFS 6950 - ARC should cache compressed data)

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes #7043
2018-01-16 10:18:08 -08:00
George Amanakis
be54a13c3e Fix percentage styling in zfs-module-parameters.5
Replace "percent" with "%", add bold to default values.

Reviewed-by: bunder2015 <omfgbunder@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #7018
2018-01-09 11:51:11 -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
Simon Guest
993669a7bf vdev_id: new slot type ses
This extends vdev_id to support a new slot type, ses, for SCSI Enclosure
Services.  With slot type ses, the disk slot numbers are determined by
using the device slot number reported by sg_ses for the device with
matching SAS address, found by querying all available enclosures.

This is primarily of use on systems with a deficient driver omitting
support for bay_identifier in /sys/devices.  In my testing, I found that
the existing slot types of port and id were not stable across disk
replacement, so an alternative was required.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Simon Guest <simon.guest@tesujimath.org>
Closes #6956
2017-12-20 09:42:07 -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
abraunegg
ca85d69097 Update zfs module parameters man5
Update zfs module parameters man5 with missing parameter details
for multiple tunings.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Alex Braunegg <alex.braunegg@gmail.com>
Closes #6785
2017-10-30 13:15:10 -07:00
abraunegg
8fc533725f Update spl module parameters man5 with missing parameter details
Update spl module parameters man5 with the following missing parameter
details for spl_panic_halt.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alex Braunegg <alex.braunegg@gmail.com>
Closes #664
2017-10-27 15:46:34 -07:00
Brian Behlendorf
a032ac4b38 OpenZFS 8558, 8602 - lwp_create() returns EAGAIN
8558 lwp_create() returns EAGAIN on system with more than 80K ZFS filesystems

On a system with more than 80K ZFS filesystems, we've seen cases
where lwp_create() will start to fail by returning EAGAIN. The
problem being, for each of those 80K ZFS filesystems, a taskq will
be created for each dataset as part of the ZIL for each dataset.

Porting Notes:
- The new nomem taskq kstat was dropped.
- Added module options and documentation for new tunings
  zfs_zil_clean_taskq_nthr_pct, zfs_zil_clean_taskq_minalloc,
  zfs_zil_clean_taskq_maxalloc, and zfs_sync_taskq_batch_pct.

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/8558
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/216d772

8602 remove unused "dp_early_sync_tasks" field from "dsl_pool" structure

Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Authored by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/8602
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/2bcb545
Closes #6779
2017-10-26 12:57:53 -07:00
Alek P
01ff0d7540 Update the default for zfs_txg_history
It's often useful to have access to txg history for debugging
purposes. This patch changes the default from 0 to 100 TXGs
worth of history preserved.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Alek Pinchuk <apinchuk@datto.com>
Closes #6691
2017-09-29 15:58:52 -07:00
sckobras
d49d9c2bdc vdev_id: implement slot numbering by port id
With HPE hardware and hpsa-driven SAS adapters, only a single phy is
reported, but no individual per-port phys (ie. no phy* entry below
port_dir), which breaks topology detection in the current sas_handler
code. Instead, slot information can be derived directly from the port
number. This change implements a new slot keyword "port" similar to
"id" and "lun", and assumes a default phy/port of 0 if no individual
phy entry can be found. It allows to use the "sas_direct" topology with
current HPE Dxxxx and Apollo 45xx JBODs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Daniel Kobras <d.kobras@science-computing.de>
Closes #6484
2017-08-14 15:18:26 -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
Fabian-Gruenbichler
b58237e769 Man page fixes
* ztest.1 man page: fix typo
* zfs-module-parameters.5 man page: fix grammar

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Closes #6492
2017-08-10 15:45:25 -07:00
Fabian-Gruenbichler
945b7f1c63 spl-module-parameters.5 manpage: fix macro
There is no '.sh' macro in troff/groff/man, only '.SH' for section
headers. I assume .sp for a line break was intended here like
in the rest of the man page.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #643
2017-08-10 15:22:31 -07:00
Ned Bass
8740cf4a2f Add line info and SET_ERROR() to ZFS debug log
Redefine the SET_ERROR macro in terms of __dprintf() so the error
return codes get logged as both tracepoint events (if tracepoints are
enabled) and as ZFS debug log entries.  This also allows us to use
the same definition of SET_ERROR() in kernel and user space.

Define a new debug flag ZFS_DEBUG_SET_ERROR=512 that may be bitwise
or'd into zfs_flags. Setting this flag enables both dprintf() and
SET_ERROR() messages in the debug log. That is, setting
ZFS_DEBUG_SET_ERROR and ZFS_DEBUG_DPRINTF|ZFS_DEBUG_SET_ERROR are
equivalent (this was done for sake of simplicity). Leaving
ZFS_DEBUG_SET_ERROR unset suppresses the SET_ERROR() messages which
helps avoid cluttering up the logs.

To enable SET_ERROR() logging, run:

  echo 1 >   /sys/module/zfs/parameters/zfs_dbgmsg_enable
  echo 512 > /sys/module/zfs/parameters/zfs_flags

Remove the zfs_set_error_class tracepoints event class since
SET_ERROR() now uses __dprintf(). This sacrifices a bit of
granularity when selecting individual tracepoint events to enable but
it makes the code simpler.

Include file, function, and line number information in debug log
entries.  The information is now added to the message buffer in
__dprintf() and as a result the zfs_dprintf_class tracepoints event
class was changed from a 4 parameter interface to a single parameter.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #6400
2017-07-25 23:09:48 -07:00
Brian Behlendorf
9ff13dbe92 Fix zpool-features.5 indentation
The userobj_accounting feature described in the zpool-features.5
man page was incorrectly indented.  Fix it.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6402
2017-07-25 18:57:00 -07:00
Olaf Faaland
379ca9cf2b Multi-modifier protection (MMP)
Add multihost=on|off pool property to control MMP.  When enabled
a new thread writes uberblocks to the last slot in each label, at a
set frequency, to indicate to other hosts the pool is actively imported.
These uberblocks are the last synced uberblock with an updated
timestamp.  Property defaults to off.

During tryimport, find the "best" uberblock (newest txg and timestamp)
repeatedly, checking for change in the found uberblock.  Include the
results of the activity test in the config returned by tryimport.
These results are reported to user in "zpool import".

Allow the user to control the period between MMP writes, and the
duration of the activity test on import, via a new module parameter
zfs_multihost_interval.  The period is specified in milliseconds.  The
activity test duration is calculated from this value, and from the
mmp_delay in the "best" uberblock found initially.

Add a kstat interface to export statistics about Multiple Modifier
Protection (MMP) updates. Include the last synced txg number, the
timestamp, the delay since the last MMP update, the VDEV GUID, the VDEV
label that received the last MMP update, and the VDEV path.  Abbreviated
output below.

$ cat /proc/spl/kstat/zfs/mypool/multihost
31 0 0x01 10 880 105092382393521 105144180101111
txg   timestamp  mmp_delay   vdev_guid   vdev_label vdev_path
20468    261337  250274925   68396651780       3    /dev/sda
20468    261339  252023374   6267402363293     1    /dev/sdc
20468    261340  252000858   6698080955233     1    /dev/sdx
20468    261341  251980635   783892869810      2    /dev/sdy
20468    261342  253385953   8923255792467     3    /dev/sdd
20468    261344  253336622   042125143176      0    /dev/sdab
20468    261345  253310522   1200778101278     2    /dev/sde
20468    261346  253286429   0950576198362     2    /dev/sdt
20468    261347  253261545   96209817917       3    /dev/sds
20468    261349  253238188   8555725937673     3    /dev/sdb

Add a new tunable zfs_multihost_history to specify the number of MMP
updates to store history for. By default it is set to zero meaning that
no MMP statistics are stored.

When using ztest to generate activity, for automated tests of the MMP
function, some test functions interfere with the test.  For example, the
pool is exported to run zdb and then imported again.  Add a new ztest
function, "-M", to alter ztest behavior to prevent this.

Add new tests to verify the new functionality.  Tests provided by
Giuseppe Di Natale.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #745
Closes #6279
2017-07-13 13:54:00 -04:00
LOLi
cf8738d853 Add port of FreeBSD 'volmode' property
The volmode property may be set to control the visibility of ZVOL
block devices.

This allow switching ZVOL between three modes:
   full - existing fully functional behaviour (default)
   dev  - hide partitions on ZVOL block devices
   none - not exposing volumes outside ZFS

Additionally the new zvol_volmode module parameter can be used to
control the default behaviour.

This functionality can be used, for instance, on "backup" pools to
avoid cluttering /dev with unneeded zd* devices.

Original-patch-by: mav <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>

FreeBSD-commit: https://github.com/freebsd/freebsd/commit/dd28e6bb
Closes #1796 
Closes #3438 
Closes #6233
2017-07-12 13:05:37 -07:00
chrisrd
627791f3c0 Fix manual description of zfs_arc_dnode_limit
In arc_evict_state() we start pruning when arc_dnode_size >
arc_dnode_limit, i.e. arc_dnode_limit is a ceiling rather than a
floor.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Closes #6228
2017-06-14 13:23:02 -07:00
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
Brian Behlendorf
8fa5250f5d Default to zvol_request_async=0
Change the default ZVOL behavior so requests are handled asynchronously.
This behavior is functionally the same as in the zfs-0.6.4 release.

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #5902
2017-05-04 18:01:50 -04:00
Debabrata Banerjee
03b60eee78 Allow scaling of arc in proportion to pagecache
When multiple filesystems are in use, memory pressure causes arc_cache
to collapse to a minimum. Allow arc_cache to maintain proportional size
even when hit rates are disproportionate. We do this only via evictable
size from the kernel shrinker, thus it's only in effect under memory
pressure.

AKAMAI: zfs: CR 3695072
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Closes #6035
2017-05-02 15:50:49 -04:00
Chunwei Chen
692e55b8fe Reinstate zvol_taskq to fix aio on zvol
Commit 37f9dac removed the zvol_taskq for processing zvol requests.
This was removed as part of switching to make_request_fn and was
motivated by a concern at the time over dispatch latency.

However, this also made all bio request synchronous, and caused
serious performance issues as the bio submitter would wait for
every bio it submitted, effectively making the IO depth 1.

This patch reinstate zvol_taskq, and to make sure overlapped I/Os
are ordered properly, we take range lock in zvol_request, and pass
it along with bio to the I/O functions zvol_{write,discard,read}.

In order to facilitate benchmarks a zvol_request_sync module
option was added to switch between sync and async request handling.
For the moment, the default behavior is synchronous but this is
likely to change pending additional testing.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #5824
2017-04-26 13:54:40 -07:00
Tim Chase
e815485fe9 Update documentation for zfs_vdev_queue_depth_pct
It was documented as being related to zfs_vdev_async_max_active
when it is actually related to zfs_vdev_async_write_max_active.
Also, expand the documentation to describe the allocation throttle
which was introduced as part of OpenZFS 7090 in 3dfb57a.

Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #6064
2017-04-26 13:48:28 -07:00
bunder2015
603a178479 Fix typo in zfs-module-parameters man page
Fix typo in zfs-module-parameters man page

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Mike McQuaid <mike@mikemcquaid.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Reviewed-by: Jason Zaman <jason@perfinion.com>
Reviewed-by: Ned Bass <bass6@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Hajo Möller <dasjoe@gmail.com>
Reviewed-by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: DHE <git@dehacked.net>
Reviewed-by: Matthew Thode <prometheanfire@gentoo.org>
Reviewed-by: Thomas Caputi <tcaputi@datto.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: kernelOfTruth <kerneloftruth@gmail.com>
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: ilovezfs <ilovezfs@icloud.com>
Reviewed-by: @jwittlincohen
Reviewed-by: Jack Draak <jackdraak@gmail.com>
Reviewed-by: @ptx0
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: @Kokokokoka
Reviewed-by: @JCount <JCount@hush.ai>
Signed-off-by: bunder2015 <omfgbunder@gmail.com>
Closes #6054
2017-04-24 10:56:44 -07:00
DeHackEd
321204bec6 Typo in zfs-module-parameters(5)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes #6061
2017-04-24 10:34:37 -07:00
DHE
06226b5936 Increase zfs_vdev_async_write_min_active to 2
Resilver operations frequently cause only a small amount of dirty data
to be written to disk at a time, resulting in the IO scheduler to only
issue 1 write at a time to the resilvering disk. When it is rotational
media the drive will often travel past the next sector to be written
before receiving a write command from ZFS, significantly delaying the
write of the next sector.

Raise zfs_vdev_async_write_min_active so that drives are kept fed
during resilvering.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Issue #4825
Closes #5926
2017-04-14 14:03:44 -07:00
Debabrata Banerjee
66aca24730 SEEK_HOLE should not block on txg_wait_synced()
Force flushing of txg's can be painfully slow when competing for disk
IO, since this is a process meant to execute asynchronously. Optimize
this path via allowing data/hole seeking if the file is clean, but if
dirty fall back to old logic. This is a compromise to disabling the
feature entirely.

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: Debabrata Banerjee <dbanerje@akamai.com>
Closes #4306
Closes #5962
2017-04-13 10:51:20 -07:00
Giuseppe Di Natale
42db43e982 OpenZFS 2932 - support crash dumps to raidz, etc. pools
Authored by: Bill Pijewski <wdp@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/2932
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/810e43b
Closes #5984
Closes #5216
2017-04-10 10:24:17 -07:00
wli5
39ccc90967 Update documentation for new parameter "zfs_qat_disable"
Update documentation in zfs-module-parameters.5 for new
parameter "zfs_qat_disable" which was introduced by #5846.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Weigang Li <weigang.li@intel.com>
Closes #5914
2017-03-27 12:33:57 -07:00
Matthew Ahrens
c30e58c462 zfs_arc_num_sublists_per_state should be common to all multilists
The global tunable zfs_arc_num_sublists_per_state is used by the ARC and
the dbuf cache, and other users are planned. We should change this
tunable to be common to all multilists.  This tuning may be overridden
on a per-multilist basis.

Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #5764
2017-02-15 15:49:33 -08:00
David Quigley
bef78122e6 Add missing module_param for zfs_per_txg_dirty_frees_percent
When the code was added this tunable was not exposed via module params. Also it
was not documented. This patch changes the type from a uint32 to a ulong as
done with other percentage tunables and also documents it in the
zfs-module-parameters man page.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: David Quigley <david.quigley@intel.com>
Closes #5750
2017-02-07 09:44:03 -08:00
Tim Chase
b81a3ddc32 Update deadman operation to better align with upstream OpenZFS
The deadman in ZoL didn't behave quite as it did in upstream
OpenZFS.  In addition to the 2 purposes for which OpenZFS used the
zfs_deadman_synctime_ms parameter, ZoL also used it to determine how
frequently the deadman would fire once it has been triggered.

This patch adds the zfs_deadman_checktime_ms parameter to control how
frequently the subsequent checks are performed.

The deadman is now disabled for suspended pools.

As had been the case, unlike upstream OpenZFS, ZoL will not panic when
a hung IO is detected.

The module parameter documentation has been upated to include the new
parameter and to better describe the operation of the deadmen.
    
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #5695
2017-01-31 14:19:08 -08:00
Håkan Johansson
9ef3906a5a Minor man-page formatting fixes
fB -> \fB in zpool.8 (Properties -> cachefile)
\fN -> \fB in zfs-module-parameters.5 (zfs_dirty_data_max_max_percent)
Three | -> \fR|\fI fixes for arguments of diff and inherit in zfs.8.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Haakan T Johansson <f96hajo@chalmers.se>
Closes #5645
2017-01-24 09:09:02 -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
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
Chunwei Chen
493492559e Limit number of tasks shown in taskq proc
To prevent holding tq_lock for too long.

Before zfsonlinux/zfs@8e71ab9, hogging delay tasks and cat /proc/spl/taskq
would easily cause a lockup. While that bug has been fixed. It's probably
still a good idea to do this just in case task lists grow too large.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #586
2016-12-01 11:06:27 -07:00
DeHackEd
6146e17ebe Fix man page formatting in zfs-module-parameters
Bold and Normal codes were mixed up in a few places resulting in
bad highlighting.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes #5397
2016-11-14 17:03:57 -08:00
Romain Dolbeau
7f547f85fe Add parity generation/rebuild using AVX-512 for x86-64
avx512f should work on all AVX512 hardware, since it only uses
Foundation instructions.

avx512bw should be faster on hardware supporting the AVW512BW
extension. We can use full-width pshufb (instead of relying on the 256
bits AVX2 pshufb). As a side-effect, the code is also unrolled more.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.github@dolbeau.name>
Closes #5219
2016-11-02 12:40:23 -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
Romain Dolbeau
24cdeaf12e Fletcher4 algorithm implemented in pure NEON for Aarch64 / ARMv8 64 bits
This is not useful on micro-architecture with a weak NEON
implementation (only 64 bits); the native version is slower &
the byteswap barely faster than scalar.  On A53 or A57, it's
a small improvement on scalar but OK for byteswap.

Results from an A53 system:
0 0 0x01 -1 0 1499068294333000 1499101101878000
implementation   native         byteswap       
scalar           1008227510     755880264      
aarch64_neon     1198098720     1044818671     
fastest          aarch64_neon   aarch64_neon 

Results from a A57 system:
0 0 0x01 -1 0 4407214734807033 4407233933777404
implementation   native         byteswap       
scalar           2302071241     1124873346     
aarch64_neon     2542214946     2245570352     
fastest          aarch64_neon   aarch64_neon 

Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.dolbeau@atos.net>
Closes #5248
2016-10-21 10:55:49 -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
Brian Behlendorf
7515f8f63d Fix file permissions
The following new test cases need to have execute permissions set:

  userquota/groupspace_003_pos.ksh
  userquota/userquota_013_pos.ksh
  userquota/userspace_003_pos.ksh
  upgrade/upgrade_userobj_001_pos.ksh
  upgrade/setup.ksh
  upgrade/cleanup.ksh

The following source files accidentally were marked executable:

  lib/libzpool/kernel.c
  lib/libshare/nfs.c
  lib/libzfs/libzfs_dataset.c
  lib/libzfs/libzfs_util.c
  tests/zfs-tests/cmd/rm_lnkcnt_zero_file/rm_lnkcnt_zero_file.c
  tests/zfs-tests/cmd/dir_rd_update/dir_rd_update.c
  cmd/zed/zed_exec.c
  module/icp/core/kcf_sched.c
  module/zfs/dsl_pool.c
  module/zfs/arc.c
  module/nvpair/nvpair.c
  man/man5/zfs-module-parameters.5

Reviewed-by: GeLiXin <ge.lixin@zte.com.cn>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #5241
2016-10-08 14:57:56 -07:00
Jinshan Xiong
1de321e626 Add support for user/group dnode accounting & quota
This patch tracks dnode usage for each user/group in the
DMU_USER/GROUPUSED_OBJECT ZAPs. ZAP entries dedicated to dnode
accounting have the key prefixed with "obj-" followed by the UID/GID
in string format (as done for the block accounting).
A new SPA feature has been added for dnode accounting as well as
a new ZPL version. The SPA feature must be enabled in the pool
before upgrading the zfs filesystem. During the zfs version upgrade,
a "quotacheck" will be executed by marking all dnode as dirty.

ZoL-bug-id: https://github.com/zfsonlinux/zfs/issues/3500

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: Johann Lombardi <johann.lombardi@intel.com>
2016-10-07 09:45:13 -07:00
ilovezfs
125a406e24 OpenZFS 6585 - sha512, skein, and edonr have an unenforced dependency on extensible dataset
Authored by: ilovezfs <ilovezfs@icloud.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported by: Tony Hutter <hutter2@llnl.gov>

In any pool without the extensible dataset feature flag already enabled,
creating a dataset with dedup set to use one of the new checksums would
result in the following panic as soon as any data was added:

panic[cpu0]/thread=ffffff0006761c40: feature_get_refcount(spa, feature,
&refcount) != 48 (0x30 != 0x30), file: ../../common/fs/zfs/zfeature.c
line 390

Inpsection showed that feature->fi_feature was 7, which is the value of
SPA_FEATURE_EXTENSIBLE_DATASET in the spa_feature enum.  This commit
adds extensible dataset as a dependency for the sha512, edonr, and skein
feature flags, which prevents the panic.

OpenZFS-issue: https://www.illumos.org/issues/6585
OpenZFS-commit: 892586e8a1
Porting Notes:
This code was originally from Illumos, but I actually ported it from:
openzfsonosx/zfs@b62a652
2016-10-03 14:51:21 -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
Romain Dolbeau
62a65a654e Add parity generation/rebuild using 128-bits NEON for Aarch64
This re-use the framework established for SSE2, SSSE3 and
AVX2. However, GCC is using FP registers on Aarch64, so
unlike SSE/AVX2 we can't rely on the registers being left alone
between ASM statements. So instead, the NEON code uses
C variables and GCC extended ASM syntax. Note that since
the kernel explicitly disable vector registers, they
have to be locally re-enabled explicitly.

As we use the variable's number to define the symbolic
name, and GCC won't allow duplicate symbolic names,
numbers have to be unique. Even when the code is not
going to be used (e.g. the case for 4 registers when
using the macro with only 2). Only the actually used
variables should be declared, otherwise the build
will fails in debug mode.

This requires the replacement of the XOR(X,X) syntax
by a new ZERO(X) macro, which does the same thing but
without repeating the argument. And perhaps someday
there will be a machine where there is a more efficient
way to zero a register than XOR with itself. This affects
scalar, SSE2, SSSE3 and AVX2 as they need the new macro.

It's possible to write faster implementations (different
scheduling, different unrolling, interleaving NEON and
scalar, ...) for various cores, but this one has the
advantage of fitting in the current state of the code,
and thus is likely easier to review/check/merge.

The only difference between aarch64-neon and aarch64-neonx2
is that aarch64-neonx2 unroll some functions some more.

Reviewed-by: Gvozden Neskovic <neskovic@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.dolbeau@atos.net>
Closes #4801
2016-10-03 09:44:00 -07:00
Brian Behlendorf
9ea9e0b9a1 Enable ignore_hole_birth module option by default
Enable ignore_hole_birth by default until all known hole birth bugs
have been resolved and relevant test cases added.

Reviewed-by: Boris Protopopov <boris.protopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4809
Closes #5099
2016-09-16 14:05:30 -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
GeLiXin
9907cc1cc8 Add zfs_arc_meta_limit_percent tunable
ARC will evict meta buffers that exceed the arc_meta_limit. Before a further
investigating on whether we should take special protection on meta buffers,
this tunable make arc_meta_limit adjustable for different workloads.

People can set zfs_arc_meta_limit_percent to any value while insmod zfs.ko,
so some range check is added to guarantee a suitable arc_meta_limit.

Suggested by Tim Chase, zfs_arc_dnode_limit is changed to a percent-style
tunable as well.

Signed-off-by: GeLiXin <ge.lixin@zte.com.cn>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4957
2016-08-23 13:03:01 -07:00
Gvozden Neskovic
70b258fc96 Fletcher4 implementation using avx512f instruction set
Algorithm runs 8 parallel sums, consuming 8x uint32_t elements per
loop iteration. Size alignment of main fletcher4 methods is adjusted
accordingly. New implementation is called 'avx512f'.

Note: byteswap method can be implemented more efficiently when avx512bw hardware
becomes available. Currently, it is ~ 2x slower than native method.

Table shows result of full (native) fletcher4 calculation for different buffer size:

fletcher4   4KB     16KB    64KB    128KB   256KB   1MB     16MB
--------------------------------------------------------------------
[scalar]    1213    1228    1231    1231    1225    1200    1160
[sse2]      2374    2442    2459    2456    2462    2250    2220
[avx2]      4288    4753    4871    4893    4900    4050    3882
[avx512f]   5975    8445    9196    9221    9262    6307    5620

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4952
2016-08-16 14:11:14 -07:00
Rich Ercolani
6d836e6f8b Add tunable to ignore hole_birth
Adds a module option which disables the hole_birth optimization
which has been responsible for several recent bugs, including
issue #4050.

Original-patch: https://gist.github.com/pcd1193182/2c0cd47211f3aee623958b4698836c48
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4833
2016-08-15 09:52:56 -07:00
Tim Chase
25458cbef9 Limit the amount of dnode metadata in the ARC
Metadata-intensive workloads can cause the ARC to become permanently
filled with dnode_t objects as they're pinned by the VFS layer.
Subsequent data-intensive workloads may only benefit from about
25% of the potential ARC (arc_c_max - arc_meta_limit).

In order to help track metadata usage more precisely, the other_size
metadata arcstat has replaced with dbuf_size, dnode_size and bonus_size.

The new zfs_arc_dnode_limit tunable, which defaults to 10% of
zfs_arc_meta_limit, defines the minimum number of bytes which is desirable
to be consumed by dnodes.  Attempts to evict non-metadata will trigger
async prune tasks if the space used by dnodes exceeds this limit.

The new zfs_arc_dnode_reduce_percent tunable specifies the amount by
which the excess dnode space is attempted to be pruned as a percentage of
the amount by which zfs_arc_dnode_limit is being exceeded.  By default,
it tries to unpin 10% of the dnodes.

The problem of dnode metadata pinning was observed with the following
testing procedure (in this example, zfs_arc_max is set to 4GiB):

    - Create a large number of small files until arc_meta_used exceeds
      arc_meta_limit (3GiB with default tuning) and arc_prune
      starts increasing.

    - Create a 3GiB file with dd.  Observe arc_mata_used.  It will still
      be around 3GiB.

    - Repeatedly read the 3GiB file and observe arc_meta_limit as before.
      It will continue to stay around 3GiB.

With this modification, space for the 3GiB file is gradually made
available as subsequent demands on the ARC are made.  The previous behavior
can be restored by setting zfs_arc_dnode_limit to the same value as the
zfs_arc_meta_limit.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4345
Issue #4512
Issue #4773
Closes #4858
2016-07-25 15:26:38 -07:00
Gvozden Neskovic
c9187d867f Fixes and enhancements of SIMD raidz parity
- Implementation lock replaced with atomic variable

- Trailing whitespace is removed from user specified parameter, to enhance
experience when using commands that add newline, e.g. `echo`

- raidz_test: remove dependency on `getrusage()` and RUSAGE_THREAD, Issue #4813

- silence `cppcheck` in vdev_raidz, partial solution of Issue #1392

- Minor fixes and cleanups

- Enable use of original parity methods in [fastest] configuration.
New opaque original ops structure, representing native methods, is added
to supported raidz methods. Original parity methods are executed if selected
implementation has NULL fn pointer.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4813
Issue #1392
2016-07-19 16:43:07 -07:00
Tyler J. Stachecki
35a76a0366 Implementation of SSE optimized Fletcher-4
Builds off of 1eeb4562 (Implementation of AVX2 optimized Fletcher-4)
This commit adds another implementation of the Fletcher-4 algorithm.
It is automatically selected at module load if it benchmarks higher
than all other available implementations.

The module benchmark was also amended to analyze the performance of
the byteswap-ed version of Fletcher-4, as well as the non-byteswaped
version. The average performance of the two is used to select the
the fastest implementation available on the host system.

Adds a pair of fields to an existing zcommon module parameter:
-  zfs_fletcher_4_impl (str)
    "sse2"    - new SSE2 implementation if available
    "ssse3"   - new SSSE3 implementation if available

Signed-off-by: Tyler J. Stachecki <stachecki.tyler@gmail.com>
Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4789
2016-07-15 10:42:35 -07:00
Gvozden Neskovic
ae25d22235 Add RAID-Z routines for SSE2 instruction set, in x86_64 mode.
The patch covers low-end and older x86 CPUs.  Parity generation is
equivalent to SSSE3 implementation, but reconstruction is somewhat
slower.  Previous 'sse' implementation is renamed to 'ssse3' to
indicate highest instruction set used.

Benchmark results:
scalar_rec_p                    4    720476442
scalar_rec_q                    4    187462804
scalar_rec_r                    4    138996096
scalar_rec_pq                   4    140834951
scalar_rec_pr                   4    129332035
scalar_rec_qr                   4    81619194
scalar_rec_pqr                  4    53376668

sse2_rec_p                      4    2427757064
sse2_rec_q                      4    747120861
sse2_rec_r                      4    499871637
sse2_rec_pq                     4    522403710
sse2_rec_pr                     4    464632780
sse2_rec_qr                     4    319124434
sse2_rec_pqr                    4    205794190

ssse3_rec_p                     4    2519939444
ssse3_rec_q                     4    1003019289
ssse3_rec_r                     4    616428767
ssse3_rec_pq                    4    706326396
ssse3_rec_pr                    4    570493618
ssse3_rec_qr                    4    400185250
ssse3_rec_pqr                   4    377541245

original_rec_p                  4    691658568
original_rec_q                  4    195510948
original_rec_r                  4    26075538
original_rec_pq                 4    103087368
original_rec_pr                 4    15767058
original_rec_qr                 4    15513175
original_rec_pqr                4    10746357

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4783
2016-07-13 10:24:55 -07:00
Ned Bass
50c957f702 Implement large_dnode pool feature
Justification
-------------

This feature adds support for variable length dnodes. Our motivation is
to eliminate the overhead associated with using spill blocks.  Spill
blocks are used to store system attribute data (i.e. file metadata) that
does not fit in the dnode's bonus buffer. By allowing a larger bonus
buffer area the use of a spill block can be avoided.  Spill blocks
potentially incur an additional read I/O for every dnode in a dnode
block. As a worst case example, reading 32 dnodes from a 16k dnode block
and all of the spill blocks could issue 33 separate reads. Now suppose
those dnodes have size 1024 and therefore don't need spill blocks.  Then
the worst case number of blocks read is reduced to from 33 to two--one
per dnode block. In practice spill blocks may tend to be co-located on
disk with the dnode blocks so the reduction in I/O would not be this
drastic. In a badly fragmented pool, however, the improvement could be
significant.

ZFS-on-Linux systems that make heavy use of extended attributes would
benefit from this feature. In particular, ZFS-on-Linux supports the
xattr=sa dataset property which allows file extended attribute data
to be stored in the dnode bonus buffer as an alternative to the
traditional directory-based format. Workloads such as SELinux and the
Lustre distributed filesystem often store enough xattr data to force
spill bocks when xattr=sa is in effect. Large dnodes may therefore
provide a performance benefit to such systems.

Other use cases that may benefit from this feature include files with
large ACLs and symbolic links with long target names. Furthermore,
this feature may be desirable on other platforms in case future
applications or features are developed that could make use of a
larger bonus buffer area.

Implementation
--------------

The size of a dnode may be a multiple of 512 bytes up to the size of
a dnode block (currently 16384 bytes). A dn_extra_slots field was
added to the current on-disk dnode_phys_t structure to describe the
size of the physical dnode on disk. The 8 bits for this field were
taken from the zero filled dn_pad2 field. The field represents how
many "extra" dnode_phys_t slots a dnode consumes in its dnode block.
This convention results in a value of 0 for 512 byte dnodes which
preserves on-disk format compatibility with older software.

Similarly, the in-memory dnode_t structure has a new dn_num_slots field
to represent the total number of dnode_phys_t slots consumed on disk.
Thus dn->dn_num_slots is 1 greater than the corresponding
dnp->dn_extra_slots. This difference in convention was adopted
because, unlike on-disk structures, backward compatibility is not a
concern for in-memory objects, so we used a more natural way to
represent size for a dnode_t.

The default size for newly created dnodes is determined by the value of
a new "dnodesize" dataset property. By default the property is set to
"legacy" which is compatible with older software. Setting the property
to "auto" will allow the filesystem to choose the most suitable dnode
size. Currently this just sets the default dnode size to 1k, but future
code improvements could dynamically choose a size based on observed
workload patterns. Dnodes of varying sizes can coexist within the same
dataset and even within the same dnode block. For example, to enable
automatically-sized dnodes, run

 # zfs set dnodesize=auto tank/fish

The user can also specify literal values for the dnodesize property.
These are currently limited to powers of two from 1k to 16k. The
power-of-2 limitation is only for simplicity of the user interface.
Internally the implementation can handle any multiple of 512 up to 16k,
and consumers of the DMU API can specify any legal dnode value.

The size of a new dnode is determined at object allocation time and
stored as a new field in the znode in-memory structure. New DMU
interfaces are added to allow the consumer to specify the dnode size
that a newly allocated object should use. Existing interfaces are
unchanged to avoid having to update every call site and to preserve
compatibility with external consumers such as Lustre. The new
interfaces names are given below. The versions of these functions that
don't take a dnodesize parameter now just call the _dnsize() versions
with a dnodesize of 0, which means use the legacy dnode size.

New DMU interfaces:
  dmu_object_alloc_dnsize()
  dmu_object_claim_dnsize()
  dmu_object_reclaim_dnsize()

New ZAP interfaces:
  zap_create_dnsize()
  zap_create_norm_dnsize()
  zap_create_flags_dnsize()
  zap_create_claim_norm_dnsize()
  zap_create_link_dnsize()

The constant DN_MAX_BONUSLEN is renamed to DN_OLD_MAX_BONUSLEN. The
spa_maxdnodesize() function should be used to determine the maximum
bonus length for a pool.

These are a few noteworthy changes to key functions:

* The prototype for dnode_hold_impl() now takes a "slots" parameter.
  When the DNODE_MUST_BE_FREE flag is set, this parameter is used to
  ensure the hole at the specified object offset is large enough to
  hold the dnode being created. The slots parameter is also used
  to ensure a dnode does not span multiple dnode blocks. In both of
  these cases, if a failure occurs, ENOSPC is returned. Keep in mind,
  these failure cases are only possible when using DNODE_MUST_BE_FREE.

  If the DNODE_MUST_BE_ALLOCATED flag is set, "slots" must be 0.
  dnode_hold_impl() will check if the requested dnode is already
  consumed as an extra dnode slot by an large dnode, in which case
  it returns ENOENT.

* The function dmu_object_alloc() advances to the next dnode block
  if dnode_hold_impl() returns an error for a requested object.
  This is because the beginning of the next dnode block is the only
  location it can safely assume to either be a hole or a valid
  starting point for a dnode.

* dnode_next_offset_level() and other functions that iterate
  through dnode blocks may no longer use a simple array indexing
  scheme. These now use the current dnode's dn_num_slots field to
  advance to the next dnode in the block. This is to ensure we
  properly skip the current dnode's bonus area and don't interpret it
  as a valid dnode.

zdb
---
The zdb command was updated to display a dnode's size under the
"dnsize" column when the object is dumped.

For ZIL create log records, zdb will now display the slot count for
the object.

ztest
-----
Ztest chooses a random dnodesize for every newly created object. The
random distribution is more heavily weighted toward small dnodes to
better simulate real-world datasets.

Unused bonus buffer space is filled with non-zero values computed from
the object number, dataset id, offset, and generation number.  This
helps ensure that the dnode traversal code properly skips the interior
regions of large dnodes, and that these interior regions are not
overwritten by data belonging to other dnodes. A new test visits each
object in a dataset. It verifies that the actual dnode size matches what
was stored in the ztest block tag when it was created. It also verifies
that the unused bonus buffer space is filled with the expected data
patterns.

ZFS Test Suite
--------------
Added six new large dnode-specific tests, and integrated the dnodesize
property into existing tests for zfs allow and send/recv.

Send/Receive
------------
ZFS send streams for datasets containing large dnodes cannot be received
on pools that don't support the large_dnode feature. A send stream with
large dnodes sets a DMU_BACKUP_FEATURE_LARGE_DNODE flag which will be
unrecognized by an incompatible receiving pool so that the zfs receive
will fail gracefully.

While not implemented here, it may be possible to generate a
backward-compatible send stream from a dataset containing large
dnodes. The implementation may be tricky, however, because the send
object record for a large dnode would need to be resized to a 512
byte dnode, possibly kicking in a spill block in the process. This
means we would need to construct a new SA layout and possibly
register it in the SA layout object. The SA layout is normally just
sent as an ordinary object record. But if we are constructing new
layouts while generating the send stream we'd have to build the SA
layout object dynamically and send it at the end of the stream.

For sending and receiving between pools that do support large dnodes,
the drr_object send record type is extended with a new field to store
the dnode slot count. This field was repurposed from unused padding
in the structure.

ZIL Replay
----------
The dnode slot count is stored in the uppermost 8 bits of the lr_foid
field. The bits were unused as the object id is currently capped at
48 bits.

Resizing Dnodes
---------------
It should be possible to resize a dnode when it is dirtied if the
current dnodesize dataset property differs from the dnode's size, but
this functionality is not currently implemented. Clearly a dnode can
only grow if there are sufficient contiguous unused slots in the
dnode block, but it should always be possible to shrink a dnode.
Growing dnodes may be useful to reduce fragmentation in a pool with
many spill blocks in use. Shrinking dnodes may be useful to allow
sending a dataset to a pool that doesn't support the large_dnode
feature.

Feature Reference Counting
--------------------------
The reference count for the large_dnode pool feature tracks the
number of datasets that have ever contained a dnode of size larger
than 512 bytes. The first time a large dnode is created in a dataset
the dataset is converted to an extensible dataset. This is a one-way
operation and the only way to decrement the feature count is to
destroy the dataset, even if the dataset no longer contains any large
dnodes. The complexity of reference counting on a per-dnode basis was
too high, so we chose to track it on a per-dataset basis similarly to
the large_block feature.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3542
2016-06-24 13:13:21 -07:00
Gvozden Neskovic
ab9f4b0b82 SIMD implementation of vdev_raidz generate and reconstruct routines
This is a new implementation of RAIDZ1/2/3 routines using x86_64
scalar, SSE, and AVX2 instruction sets. Included are 3 parity
generation routines (P, PQ, and PQR) and 7 reconstruction routines,
for all RAIDZ level. On module load, a quick benchmark of supported
routines will select the fastest for each operation and they will
be used at runtime. Original implementation is still present and
can be selected via module parameter.

Patch contains:
- specialized gen/rec routines for all RAIDZ levels,
- new scalar raidz implementation (unrolled),
- two x86_64 SIMD implementations (SSE and AVX2 instructions sets),
- fastest routines selected on module load (benchmark).
- cmd/raidz_test - verify and benchmark all implementations
- added raidz_test to the ZFS Test Suite

New zfs module parameters:
- zfs_vdev_raidz_impl (str): selects the implementation to use. On
  module load, the parameter will only accept first 3 options, and
  the other implementations can be set once module is finished
  loading. Possible values for this option are:
    "fastest" - use the fastest math available
    "original" - use the original raidz code
    "scalar" - new scalar impl
    "sse" - new SSE impl if available
    "avx2" - new AVX2 impl if available

See contents of `/sys/module/zfs/parameters/zfs_vdev_raidz_impl` to
get the list of supported values. If an implementation is not supported
on the system, it will not be shown. Currently selected option is
enclosed in `[]`.

Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4328
2016-06-21 09:27:26 -07:00
Jinshan Xiong
1eeb4562a7 Implementation of AVX2 optimized Fletcher-4
New functionality:
- Preserves existing scalar implementation.
- Adds AVX2 optimized Fletcher-4 computation.
- Fastest routines selected on module load (benchmark).
- Test case for Fletcher-4 added to ztest.

New zcommon module parameters:
-  zfs_fletcher_4_impl (str): selects the implementation to use.
    "fastest" - use the fastest version available
    "cycle"   - cycle trough all available impl for ztest
    "scalar"  - use the original version
    "avx2"    - new AVX2 implementation if available

Performance comparison (Intel i7 CPU, 1MB data buffers):
- Scalar:  4216 MB/s
- AVX2:   14499 MB/s

See contents of `/sys/module/zcommon/parameters/zfs_fletcher_4_impl`
to get list of supported values. If an implementation is not supported
on the system, it will not be shown. Currently selected option is
enclosed in `[]`.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4330
2016-06-02 14:30:51 -07:00
DHE
8342673502 Improve zfs-module-parameters(5)
Various rewrites to the descriptions of module parameters. Corrects
spelling mistakes, makes descriptions them more user-friendly and
describes some ZFS quirks which should be understood before changing
parameter values.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4671
2016-05-23 11:08:45 -07:00
Richard Laager
1c0120832c Correct typo in spa_load_verify_metadata docs
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4471
2016-03-29 18:33:16 -07:00
smh
9f500936c8 FreeBSD r256956: Improve ZFS N-way mirror read performance by using load and locality information.
The existing algorithm selects a preferred leaf vdev based on offset of the zio
request modulo the number of members in the mirror. It assumes the devices are
of equal performance and that spreading the requests randomly over both drives
will be sufficient to saturate them. In practice this results in the leaf vdevs
being under utilized.

The new algorithm takes into the following additional factors:
* Load of the vdevs (number outstanding I/O requests)
* The locality of last queued I/O vs the new I/O request.

Within the locality calculation additional knowledge about the underlying vdev
is considered such as; is the device backing the vdev a rotating media device.

This results in performance increases across the board as well as significant
increases for predominantly streaming loads and for configurations which don't
have evenly performing devices.

The following are results from a setup with 3 Way Mirror with 2 x HD's and
1 x SSD from a basic test running multiple parrallel dd's.

With pre-fetch disabled (vfs.zfs.prefetch_disable=1):

== Stripe Balanced (default) ==
Read 15360MB using bs: 1048576, readers: 3, took 161 seconds @ 95 MB/s
== Load Balanced (zfslinux) ==
Read 15360MB using bs: 1048576, readers: 3, took 297 seconds @ 51 MB/s
== Load Balanced (locality freebsd) ==
Read 15360MB using bs: 1048576, readers: 3, took 54 seconds @ 284 MB/s

With pre-fetch enabled (vfs.zfs.prefetch_disable=0):

== Stripe Balanced (default) ==
Read 15360MB using bs: 1048576, readers: 3, took 91 seconds @ 168 MB/s
== Load Balanced (zfslinux) ==
Read 15360MB using bs: 1048576, readers: 3, took 108 seconds @ 142 MB/s
== Load Balanced (locality freebsd) ==
Read 15360MB using bs: 1048576, readers: 3, took 48 seconds @ 320 MB/s

In addition to the performance changes the code was also restructured, with
the help of Justin Gibbs, to provide a more logical flow which also ensures
vdevs loads are only calculated from the set of valid candidates.

The following additional sysctls where added to allow the administrator
to tune the behaviour of the load algorithm:
* vfs.zfs.vdev.mirror.rotating_inc
* vfs.zfs.vdev.mirror.rotating_seek_inc
* vfs.zfs.vdev.mirror.rotating_seek_offset
* vfs.zfs.vdev.mirror.non_rotating_inc
* vfs.zfs.vdev.mirror.non_rotating_seek_inc

These changes where based on work started by the zfsonlinux developers:
https://github.com/zfsonlinux/zfs/pull/1487

Reviewed by:	gibbs, mav, will
MFC after:	2 weeks
Sponsored by:	Multiplay

References:
  https://github.com/freebsd/freebsd@5c7a6f5d
  https://github.com/freebsd/freebsd@31b7f68d
  https://github.com/freebsd/freebsd@e186f564

Performance Testing:
  https://github.com/zfsonlinux/zfs/pull/4334#issuecomment-189057141

Porting notes:
- The tunables were adjusted to have ZoL-style names.
- The code was modified to use ZoL's vd_nonrot.
- Fixes were done to make cstyle.pl happy
- Merge conflicts were handled manually
- freebsd/freebsd@e186f564bc by my
  collegue Andriy Gapon has been included. It applied perfectly, but
  added a cstyle regression.
- This replaces 556011dbec entirely.
- A typo "IO'a" has been corrected to say "IO's"
- Descriptions of new tunables were added to man/man5/zfs-module-parameters.5.

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4334
2016-02-26 11:24:35 -08:00
Brian Behlendorf
8a09d5fd46 Add l2arc_max_block_size tunable
Set a limit for the largest compressed block which can be written
to an L2ARC device.  By default this limit is set to 16M so there
is no change in behavior.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #4323
2016-02-25 09:44:00 -08:00
Chunwei Chen
8f3b403a73 Allow kicking a taskq to spawn more threads
This patch add a module parameter spl_taskq_kick. When writing non-zero value
to it, it will scan all the taskq, if a taskq contains a task pending for more
than 5 seconds, it will be forced to spawn a new thread. This is use as an
emergency recovery from deadlock, not a general solution.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #529
2016-02-05 14:08:31 -08:00
kernelOfTruth
a966c5640e Reintroduce zfs_remove() synchronous deletes
Reintroduce a slightly adapted version of the Illumos logic for
synchronous unlinks.  The basic idea here is that only files
smaller than zfs_delete_blocks (20480) blocks should be deleted
synchronously.  Unlinking larger files should be handled
asynchronously to minimize impact to the caller.

To accomplish this iput() which is responsible for calling
zfs_znode_delete() on Linux is only called in the delete_now
path.  Otherwise zfs_async_iput() is used which allows the
last reference to be dropped by a taskq thread effectively
making the removal asynchronous.

Porting notes:
- Add zfs_delete_blocks module option for performance analysis.
  The default value is DMU_MAX_DELETEBLKCNT which is the same
  as upstream.  Reducing this value means that smaller files
  will be unlinked asynchronously like large files.
- All occurrences of zfsvfs changes to zsb.

Ported-by: KernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-01-26 15:26:02 -08:00
George Wilson
ba5ad9a48d Illumos 6251 - add tunable to disable free_bpobj processing
6251 - add tunable to disable free_bpobj processing
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Simon Klinkert <simon.klinkert@gmail.com>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Albert Lee <trisk@omniti.com>
Reviewed by: Xin Li <delphij@freebsd.org>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/6251
  https://github.com/illumos/illumos-gate/commit/139510f

Porting notes:
- Added as module option declaration.
- Added to zfs-module-parameters.5 man page.

Ported-by: Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-01-25 13:15:17 -08:00
Brian Behlendorf
d297a5a3a1 Add spl_kmem_cache_kmem_threads man page entry
The spl_kmem_cache_kmem_threads module option was accidentally
omitted from the documentation.  Add it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #512
2016-01-12 15:04:37 -08:00
Matthew Ahrens
7f60329a26 Illumos 5987 - zfs prefetch code needs work
5987 zfs prefetch code needs work
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Approved by: Gordon Ross <gordon.ross@nexenta.com>

References:
  https://www.illumos.org/issues/5987 zfs prefetch code needs work
  illumos/illumos-gate@cf6106c 5987 zfs prefetch code needs work

Porting notes:
- [module/zfs/dbuf.c]
  - 5f6d0b6 Handle block pointers with a corrupt logical size
- [module/zfs/dmu_zfetch.c]
  - c65aa5b Fix gcc missing parenthesis warnings
  - 428870f Update core ZFS code from build 121 to build 141.
  - 79c76d5 Change KM_PUSHPAGE -> KM_SLEEP
  - b8d06fc Switch KM_SLEEP to KM_PUSHPAGE
  - Account for ISO C90 - mixed declarations and code - warnings
  - Module parameters (new/changed):
    - Replaced zfetch_block_cap with zfetch_max_distance
      (Max bytes to prefetch per stream (default 8MB; 8 * 1024 * 1024))
    - Preserved zfs_prefetch_disable as 'int' for consistency with
      existing Linux module options.
- [include/sys/trace_arc.h]
  - Added new tracepoints
    - DEFINE_ARC_BUF_HDR_EVENT(zfs_arc__sync__wait__for__async);
    - DEFINE_ARC_BUF_HDR_EVENT(zfs_arc__demand__hit__predictive__prefetch);
- [man/man5/zfs-module-parameters.5]
  - Updated man page

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2016-01-12 09:02:33 -08:00
DHE
dcb6bed1df Make zio_taskq_batch_pct user configurable
Adds zio_taskq_batch_pct as an exported module parameter,
allowing users to modify it at module load time.

Signed-off-by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4110
2015-12-18 13:46:23 -08:00
Ned Bass
6b4e21c60e Man page white space and spelling corrections
Correct some misspelled words and grammatical errors, and remove
trailing white space in the man pages.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4115
2015-12-18 13:33:37 -08:00
Brian Behlendorf
9965059ab9 Prefetch start and end of volumes
When adding a zvol to the system prefetch zvol_prefetch_bytes from the
start and end of the volume.  Prefetching these regions of the volume is
desirable because they are likely to be accessed immediately by blkid(8),
the kernel scanning for a partition table, or another task which probes
the devices.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3659
2015-09-09 14:38:29 -07:00
Brian Behlendorf
3b36f8319d Add dbgmsg kstat
Internally ZFS keeps a small log to facilitate debugging.  By default
the log is disabled, to enable it set zfs_dbgmsg_enable=1.  The contents
of the log can be accessed by reading the /proc/spl/kstat/zfs/dbgmsg file.
Writing 0 to this proc file clears the log.

$ echo 1 >/sys/module/zfs/parameters/zfs_dbgmsg_enable
$ echo 0 >/proc/spl/kstat/zfs/dbgmsg
$ zpool import tank
$ cat /proc/spl/kstat/zfs/dbgmsg
1 0 0x01 -1 0 2492357525542 2525836565501
timestamp    message
1441141408   spa=tank async request task=1
1441141408   txg 70 open pool version 5000; software version 5000/5; ...
1441141409   spa=tank async request task=32
1441141409   txg 72 import pool version 5000; software version 5000/5; ...
1441141414   command: lt-zpool import tank

Note the zfs_dbgmsg() and dprintf() functions are both now mapped to
the same log.  As mentioned above the kernel debug log can be accessed
though the /proc/spl/kstat/zfs/dbgmsg kstat.  For user space consumers
log messages are immediately written to stdout after applying the
ZFS_DEBUG environment variable.

$ ZFS_DEBUG=on ./cmd/ztest/ztest -V

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #3728
2015-09-04 16:08:14 -07:00
Brian Behlendorf
0500e835af Support accessing .zfs/snapshot via NFS
This patch is based on the previous work done by @andrey-ve and
@yshui.  It triggers the automount by using kern_path() to traverse
to the known snapshout mount point.  Once the snapshot is mounted
NFS can access the contents of the snapshot.

Allowing NFS clients to access to the .zfs/snapshot directory would
normally mean that a root user on a client mounting an export with
'no_root_squash' would be able to use mkdir/rmdir/mv to manipulate
snapshots on the server.  To prevent configuration mistakes a
zfs_admin_snapshot module option was added which disables the
mkdir/rmdir/mv functionally.  System administators desiring this
functionally must explicitly enable it.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2797
Closes #1655
Closes #616
2015-09-04 13:23:53 -07:00
Richard Yao
37f9dac592 zvol processing should use struct bio
Internally, zvols are files exposed through the block device API. This
is intended to reduce overhead when things require block devices.
However, the ZoL zvol code emulates a traditional block device in that
it has a top half and a bottom half. This is an unnecessary source of
overhead that does not exist on any other OpenZFS platform does this.
This patch removes it. Early users of this patch reported double digit
performance gains in IOPS on zvols in the range of 50% to 80%.

Comments in the code suggest that the current implementation was done to
obtain IO merging from Linux's IO elevator. However, the DMU already
does write merging while arc_read() should implicitly merge read IOs
because only 1 thread is permitted to fetch the buffer into ARC. In
addition, commercial ZFSOnLinux distributions report that regular files
are more performant than zvols under the current implementation, and the
main consumers of zvols are VMs and iSCSI targets, which have their own
elevators to merge IOs.

Some minor refactoring allows us to register zfs_request() as our
->make_request() handler in place of the generic_make_request()
function. This eliminates the layer of code that broke IO requests on
zvols into a top half and a bottom half. This has several benefits:

1. No per zvol spinlocks.
2. No redundant IO elevator processing.
3. Interrupts are disabled only when actually necessary.
4. No redispatching of IOs when all taskq threads are busy.
5. Linux's page out routines will properly block.
6. Many autotools checks become obsolete.

An unfortunate consequence of eliminating the layer that
generic_make_request() is that we no longer calls the instrumentation
hooks for block IO accounting. Those hooks are GPL-exported, so we
cannot call them ourselves and consequently, we lose the ability to do
IO monitoring via iostat.  Since zvols are internally files mapped as
block devices, this should be okay. Anyone who is willing to accept the
performance penalty for the block IO layer's accounting could use the
loop device in between the zvol and its consumer. Alternatively, perf
and ftrace likely could be used. Also, tools like latencytop will still
work. Tools such as latencytop sometimes provide a better view of
performance bottlenecks than the traditional block IO accounting tools
do.

Lastly, if direct reclaim occurs during spacemap loading and swap is on
a zvol, this code will deadlock. That deadlock could already occur with
sync=always on zvols. Given that swap on zvols is not yet production
ready, this is not a blocker.

Signed-off-by: Richard Yao <ryao@gentoo.org>
2015-09-04 15:30:24 -04:00
Brian Behlendorf
6cde64351e Add spa_slop_shift module option
Allow for easy turning of a pools reserved free space.  Previous
versions of ZFS (v0.6.4 and earlier) held 1/64 of the pools capacity
in reserve.  Commits 3d45fdd and 0c60cc3 increased this to 1/32.
Setting spa_slop_shift=6 will restore the previous default setting.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3724
2015-09-02 09:30:18 -07:00
Andreas Buschmann
bba365cfc8 Add extra keyword 'slot' to vdev_id.conf
Add new keyword 'slot' to vdev_id.conf
This selects from where to get the slot number for a SAS/SATA disk
Needed to enable access to the physical position of a disk in a
Supermicro 2027R-AR24NV .

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Closes #3693
2015-08-30 10:03:56 -07:00
Brian Behlendorf
7e8bddd019 Update arc_memory_throttle() to check pageout
This brings the behavior of arc_memory_throttle() back in sync with
illumos.  The updated memory throttling policy roughly goes like this:

* Never throttle if more than 10% of memory is free.  This threshold
  is configurable with the zfs_arc_lotsfree_percent module option.

* Minimize any throttling of kswapd even when free memory is below
  the set threshold.  Allow it to write out pages as quickly as
  possible to help alleviate the memory pressure.

* Delay all other threads when free memory is below the set threshold
  in order to avoid compounding the memory pressure.  Buffers will be
  evicted from the ARC to reduce the issue.

The Linux specific zfs_arc_memory_throttle_disable module option has
been removed in favor of the existing zfs_arc_lotsfree_percent tuning.
Setting zfs_arc_lotsfree_percent=0 will have the same effect as
zfs_arc_memory_throttle_disable and it was therefore redundant.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3637
2015-07-30 11:52:12 -07:00
Brian Behlendorf
11f552fa90 Update arc_available_memory() to check freemem
While Linux doesn't provide detailed information about the state of
the VM it does provide us total free pages.  This information should
be incorporated in to the arc_available_memory() calculation rather
than solely relying on a signal from direct reclaim.  Conceptually
this brings arc_available_memory() back in sync with illumos.

It is also desirable that the target amount of free memory be tunable
on a system.  While the default values are expected to work well
for most workloads there may be cases where custom values are needed.
The zfs_arc_sys_free module option was added for this purpose.

zfs_arc_sys_free - The target number of bytes the ARC should leave
                   as free memory on the system.  This value can
                   checked in /proc/spl/kstat/zfs/arcstats and
                   setting this module option will override the
                   default value.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3637
2015-07-30 11:50:22 -07:00
Brian Behlendorf
6339c1b9dc Bound zvol_threads module option
The zvol_threads module option should be bounded to a reasonable
range.  The taskq must have at least 1 thread and shouldn't have
more than 1,024 at most.  The default value of 32 is a reasonable
default.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3614
2015-07-29 07:42:11 -07:00
Brian Behlendorf
62aa81a577 Add defclsyspri macro
Add a new defclsyspri macro which can be used to request the default
Linux scheduler priority.  Neither the minclsyspri or maxclsyspri map
to the default Linux kernel thread priority.  This makes it awkward to
create taskqs which run with the same priority as the rest of the kernel
threads on the system which can lead to performance issues.

All SPL callers which previously used minclsyspri or maxclsyspri have
been changed to use defclsyspri.  The vast majority of callers were
part of the test suite which won't have an external impact.  The few
places where it could impact performance the change was from maxclsyspri
to defclsyspri.  This makes it more likely the process will be scheduled
which may help performance.

To facilitate further performance analysis the spl_taskq_thread_priority
module option has been added.  When disabled (0) all newly created kernel
threads will use the default kernel thread priority.  When enabled (1)
the specified taskq priority will be used.  By default this value is
enabled (1).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-07-23 13:25:49 -07:00
Brian Behlendorf
728d6ae91e Reinstate zfs_arc_p_min_shift
Commit f521ce1 removed the minimum value for "arc_p" allowing it to
drop to zero or grow to "arc_c".  This was done to improve specific
workload which constantly dirties new "metadata" but also frequently
touches a "small" amount of mfu data (e.g. mkdir's).

This change may still be desirable but it needs to be re-investigated.
in the context of the recent ARC changes from upstream.  Therefore
this code is being restored to facilitate benchmarking.  By setting
"zfs_arc_p_min_shift=64" we easily compare the performance.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #3533
2015-07-23 09:42:32 -07:00
Colin Ian King
8f3439733f man: fix spelling mistakes in manual
A few minor mistakes than should be fixed:

zpool:
  compatability -> compatibility

zfs:
  accessable -> accessible
  availible  -> available

zfs-events:
  availible -> available

zfs-module-parameters:
  proceding -> proceeding

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3544
2015-07-01 10:58:31 -07:00
Brian Behlendorf
f7a973d99b Add TASKQ_DYNAMIC feature
Setting the TASKQ_DYNAMIC flag will create a taskq with dynamic
semantics.  Initially only a single worker thread will be created
to service tasks dispatched to the queue.  As additional threads
are needed they will be dynamically spawned up to the max number
specified by 'nthreads'.  When the threads are no longer needed,
because the taskq is empty, they will automatically terminate.

Due to the low cost of creating and destroying threads under Linux
by default new threads and spawned and terminated aggressively.
There are two modules options which can be tuned to adjust this
behavior if needed.

* spl_taskq_thread_sequential - The number of sequential tasks,
without interruption, which needed to be handled by a worker
thread before a new worker thread is spawned.  Default 4.

* spl_taskq_thread_dynamic - Provides the ability to completely
disable the use of dynamic taskqs on the system.  This is provided
for the purposes of debugging and troubleshooting.  Default 1
(enabled).

This behavior is fundamentally consistent with the dynamic taskq
implementation found in both illumos and FreeBSD.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #458
2015-06-24 15:14:18 -07:00
Etienne Dechamps
99b14de421 Make metaslab_aliquot a module parameter.
This seems generally useful. metaslab_aliquot is the ZFS allocation
granularity, which is roughly equivalent to what is called the stripe
size in traditional RAID arrays. It seems relevant to performance
tuning.

Signed-off-by: Etienne Dechamps <etienne@edechamps.fr>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-06-22 14:19:38 -07:00
Prakash Surya
ca0bf58d65 Illumos 5497 - lock contention on arcs_mtx
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Approved by: Dan McDonald <danmcd@omniti.com>

Porting notes and other significant code changes:

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

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

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

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

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

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

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

The following arcstats have been removed:

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

    l2_writes_hdr_miss

The following arcstats have been added:

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

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

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

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

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

The following module parameters have been added:

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

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

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

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

Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov
2015-06-11 10:27:25 -07:00
Turbo Fredriksson
d050c627b5 Improve on the ZFS events documentation
* Add information about the 'zpool events' command in zpool(8).
* More events and payloads defined in zfs-events(5).
* I/O Stages and I/O Flags sections added.
* Remove unused legacy "zio_deadline" payload define.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3467
2015-06-09 11:19:19 -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
Jerry Jelinek
788eb90c4c Illumos 3897 - zfs filesystem and snapshot limits
3897 zfs filesystem and snapshot limits
Author: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>

References:
  https://www.illumos.org/issues/3897
  https://github.com/illumos/illumos-gate/commit/a2afb61

Porting Notes:

dsl_dataset_snapshot_check(): reduce stack usage using kmem_alloc().

Ported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-04-28 16:22:51 -07:00
cburroughs
7008109646 align zfs_autoimport_disable manpage with reality
The default was changed in #2820.

Signed-off-by: cburroughs <chris.burroughs@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3341
2015-04-24 14:58:38 -07:00
Brian Behlendorf
74aa2ba259 Update zfs_pd_bytes_max default in zfs(8)
Commit b738bc5 should have updated the default value of zfs_pd_bytes_max
in the zfs(8) man page.  The correct default value is 50*1024*1024.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-03-31 11:55:28 -07:00
George Wilson
b738bc5a0f Illumos 5694 - traverse_prefetcher does not prefetch enough
5694 traverse_prefetcher does not prefetch enough
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Alex Reece <alex@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Bayard Bell <buffer.g.overflow@gmail.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/5694
  https://github.com/illumos/illumos-gate/commit/34d7ce05

Ported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3230
2015-03-27 15:02:50 -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
bc88866657 Fix arc_adjust_meta() behavior
The goal of this function is to evict enough meta data buffers from the
ARC in order to enforce the arc_meta_limit.  Achieving this is slightly
more complicated than it appears because it is common for data buffers
to have holds on meta data buffers.  In addition, dnode meta data buffers
will be held by the dnodes in the block preventing them from being freed.
This means we can't simply traverse the ARC and expect to always find
enough unheld meta data buffer to release.

Therefore, this function has been updated to make alternating passes
over the ARC releasing data buffers and then newly unheld meta data
buffers.  This ensures forward progress is maintained and arc_meta_used
will decrease.  Normally this is sufficient, but if required the ARC
will call the registered prune callbacks causing dentry and inodes to
be dropped from the VFS cache.  This will make dnode meta data buffers
available for reclaim.  The number of total restarts in limited by
zfs_arc_meta_adjust_restarts to prevent spinning in the rare case
where all meta data is pinned.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Issue #3160
2015-03-20 10:35:20 -07:00
Brian Behlendorf
2cbb06b561 Restructure per-filesystem reclaim
Originally when the ARC prune callback was introduced the idea was
to register a single callback for the ZPL.  The ARC could invoke this
call back if it needed the ZPL to drop dentries, inodes, or other
cache objects which might be pinning buffers in the ARC.  The ZPL
would iterate over all ZFS super blocks and perform the reclaim.

For the most part this design has worked well but due to limitations
in 2.6.35 and earlier kernels there were some problems.  This patch
is designed to address those issues.

1) iterate_supers_type() is not provided by all kernels which makes
it impossible to safely iterate over all zpl_fs_type filesystems in
a single callback.  The most straight forward and portable way to
resolve this is to register a callback per-filesystem during mount.
The arc_*_prune_callback() functions have always supported multiple
callbacks so this is functionally a very small change.

2) Commit 050d22b removed the non-portable shrink_dcache_memory()
and shrink_icache_memory() functions and didn't replace them with
equivalent functionality.  This meant that for Linux 3.1 and older
kernels the ARC had no mechanism to drop dentries and inodes from
the caches if needed.  This patch adds that missing functionality
by calling shrink_dcache_parent() to release dentries which may be
pinning inodes.  This will result in all unused cache entries being
dropped which is a bit heavy handed but it's the only interface
available for old kernels.

3) A zpl_drop_inode() callback is registered for kernels older than
2.6.35 which do not support the .evict_inode callback.  This ensures
that when the last reference on an inode is dropped it is immediately
removed from the cache.  If this isn't done than inode can end up on
the global unused LRU with no mechanism available to ZFS to drop them.
Since the ARC buffers are not dropped the hottest inodes can still
be recreated without performing disk IO.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Issue #3160
2015-03-20 10:35:20 -07:00
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
3018bffa9b Refine slab cache sizing
This change is designed to improve the memory utilization of
slabs by more carefully setting their size.  The way the code
currently works is problematic for slabs which contain large
objects (>1MB).  This is due to slabs being unconditionally
rounded up to a power of two which may result in unused space
at the end of the slab.

The reason the existing code rounds up every slab is because it
assumes it will backed by the buddy allocator.  Since the buddy
allocator can only performs power of two allocations this is
desirable because it avoids wasting any space.  However, this
logic breaks down if slab is backed by vmalloc() which operates
at a page level granularity.  In this case, the optimal thing to
do is calculate the minimum required slab size given certain
constraints (object size, alignment, objects/slab, etc).

Therefore, this patch reworks the spl_slab_size() function so
that it sizes KMC_KMEM slabs differently than KMC_VMEM slabs.
KMC_KMEM slabs are rounded up to the nearest power of two, and
KMC_VMEM slabs are allowed to be the minimum required size.

This change also reduces the default number of objects per slab.
This reduces how much memory a single cache object can pin, which
can result in significant memory saving for highly fragmented
caches.  But depending on the workload it may result in slabs
being allocated and freed more frequently.  In practice, this
has been shown to be a better default for most workloads.

Also the maximum slab size has been reduced to 4MB on 32-bit
systems.  Due to the limited virtual address space it's critical
the we be as frugal as possible.  A limit of 4M still lets us
reasonably comfortably allocate a limited number of 1MB objects.

Finally, the kmem:slab_small and kmem:slab_large SPLAT tests
were extended to provide better test coverage of various object
sizes and alignments.  Caches are created with random parameters
and their basic functionality is verified by allocating several
slabs worth of objects.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 13:55:09 -08:00
Brian Behlendorf
b1c3ae48a7 Update spl-module-parameters(5) man page
The spl-module-parameters(5) was not kept up to date.  Refresh
the man page so that it lists all the possible module options,
describes what the do, and justify why the default values are
set they way the are.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 13:55:09 -08:00
Brian Behlendorf
1a20496834 Make slab reclaim more aggressive
Many people have noticed that the kmem cache implementation is slow
to release its memory.  This patch makes the reclaim behavior more
aggressive by immediately freeing a slab once it is empty.  Unused
objects which are cached in the magazines will still prevent a slab
from being freed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 13:55:09 -08:00
Brian Behlendorf
c3eabc75b1 Refactor generic memory allocation interfaces
This patch achieves the following goals:

1. It replaces the preprocessor kmem flag to gfp flag mapping with
   proper translation logic. This eliminates the potential for
   surprises that were previously possible where kmem flags were
   mapped to gfp flags.

2. It maps vmem_alloc() allocations to kmem_alloc() for allocations
   sized less than or equal to the newly-added spl_kmem_alloc_max
   parameter.  This ensures that small allocations will not contend
   on a single global lock, large allocations can still be handled,
   and potentially limited virtual address space will not be squandered.
   This behavior is entirely different than under Illumos due to
   different memory management strategies employed by the respective
   kernels.  However, this functionally provides the semantics required.

3. The --disable-debug-kmem, --enable-debug-kmem (default), and
   --enable-debug-kmem-tracking allocators have been unified in to
   a single spl_kmem_alloc_impl() allocation function.  This was
   done to simplify the code and make it more maintainable.

4. Improve portability by exposing an implementation of the memory
   allocations functions that can be safely used in the same way
   they are used on Illumos.   Specifically, callers may safely
   use KM_SLEEP in contexts which perform filesystem IO.  This
   allows us to eliminate an entire class of Linux specific changes
   which were previously required to avoid deadlocking the system.

This change will be largely transparent to existing callers but there
are a few caveats:

1. Because the headers were refactored and extraneous includes removed
   callers may find they need to explicitly add additional #includes.
   In particular, kmem_cache.h must now be explicitly includes to
   access the SPL's kmem cache implementation.  This behavior is
   different from Illumos but it was done to avoid always masking
   the Linux slab functions when kmem.h is included.

2. Callers, like Lustre, which made assumptions about the definitions
   of KM_SLEEP, KM_NOSLEEP, and KM_PUSHPAGE will need to be updated.
   Other callers such as ZFS which did not will not require changes.

3. KM_PUSHPAGE is no longer overloaded to imply GFP_NOIO.  It retains
   its original meaning of allowing allocations to access reserved
   memory.  KM_PUSHPAGE callers can be converted back to KM_SLEEP.

4. The KM_NODEBUG flags has been retired and the default warning
   threshold increased to 32k.

5. The kmem_virt() functions has been removed.  For callers which
   need to distinguish between a physical and virtual address use
   is_vmalloc_addr().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2015-01-16 13:55:09 -08:00
Ned Bass
33b6dbbc51 Document zfs_flags module parameter
Add a table describing the debugging flags that can be set in the zfs_flags
module parameter.  Also change the module_param type to 'uint' so users aren't
shown a negative value. The updated man page text is reproduced below for
convenience.

zfs_flags (int)
            Set  additional debugging flags. The following flags may be
            bitwise-or'd together.

            +-------------------------------------------------------+
            |Value   Symbolic Name                                  |
            |        Description                                    |
            +-------------------------------------------------------+
            |    1   ZFS_DEBUG_DPRINTF                              |
            |        Enable dprintf entries in the debug log.       |
            +-------------------------------------------------------+
            |    2   ZFS_DEBUG_DBUF_VERIFY *                        |
            |        Enable extra dbuf verifications.               |
            +-------------------------------------------------------+
            |    4   ZFS_DEBUG_DNODE_VERIFY *                       |
            |        Enable extra dnode verifications.              |
            +-------------------------------------------------------+
            |    8   ZFS_DEBUG_SNAPNAMES                            |
            |        Enable snapshot name verification.             |
            +-------------------------------------------------------+
            |   16   ZFS_DEBUG_MODIFY                               |
            |        Check for illegally modified ARC buffers.      |
            +-------------------------------------------------------+
            |   32   ZFS_DEBUG_SPA                                  |
            |        Enable spa_dbgmsg entries in the debug log.    |
            +-------------------------------------------------------+
            |   64   ZFS_DEBUG_ZIO_FREE                             |
            |        Enable verification of block frees.            |
            +-------------------------------------------------------+
            |  128   ZFS_DEBUG_HISTOGRAM_VERIFY                     |
            |        Enable extra spacemap histogram verifications. |
            +-------------------------------------------------------+
            * Requires debug build.

            Default value: 0.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2988
2015-01-07 15:50:49 -08:00
Daniil Lunev
62bdd5eb7a Illumos 4924 - LZ4 Compression for metadata
Reviewed by Matthew Ahrens <mahrens@delphix.com>
Reviewed by Saso Kiselkov <skiselkov.ml@gmail.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>

References:
  https://github.com/illumos/illumos-gate/commit/b8289d2
  https://www.illumos.org/issues/3756

Porting notes:

The static function zfs_prop_activate_feature() was removed because
this change removes the only caller.  The function was not removed
from Illumos but instead left as dead code.  However, to keep gcc
happy it was removed from Linux and may be easily restored if needed.

Ported by: DHE <git@dehacked.net>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1540
2014-10-20 16:17:49 -07:00