Commit Graph

301 Commits

Author SHA1 Message Date
Allan Jude
65ad5d1165
spa.c: Replace VERIFY(nvlist_*(...) == 0) with fnvlist_* (#12678)
The fnvlist versions of the functions are fatal if they fail,
saving each call from having to include checking the result.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Allan Jude <allan@klarasystems.com>
2021-10-26 17:15:38 -06:00
Brian Behlendorf
6954c22f35
Use fallthrough macro
As of the Linux 5.9 kernel a fallthrough macro has been added which
should be used to anotate all intentional fallthrough paths.  Once
all of the kernel code paths have been updated to use fallthrough
the -Wimplicit-fallthrough option will because the default.  To
avoid warnings in the OpenZFS code base when this happens apply
the fallthrough macro.

Additional reading: https://lwn.net/Articles/794944/

Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #12441
2021-09-14 10:17:54 -06:00
Tony Nguyen
6bc61d22c4
Run arc_evict thread at higher priority
Run arc_evict thread at higher priority, nice=0, to give it more CPU
time which can improve performance for workload with high ARC evict
activities.

On mixed read/write and sequential read workloads, I've seen between
10-40% better performance.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Tony Nguyen <tony.nguyen@delphix.com>
Closes #12397
2021-08-10 11:36:26 -06:00
Mark Johnston
da27b8bc7f Initialize "autoreplace" in spa_ld_get_props()
spa_prop_find() may fail to find the specified property, in which case
it suppresses ENOENT from zap_lookup().  In this case, the return value
is left uninitialized, so spa_autoreplace was being initialized using an
uninitialized stack variable.

This was found using KMSAN.  It appears to be a regression from commit
9eb7b46ed0, which removed the initialization of "autoreplace" from the
definition.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes #12383
2021-07-26 11:53:47 -07:00
Alexander Motin
1b50749ce9
Optimize allocation throttling
Remove mc_lock use from metaslab_class_throttle_*().  The math there
is based on refcounts and so atomic, so the only race possible there
is between zfs_refcount_count() and zfs_refcount_add().  But in most
cases metaslab_class_throttle_reserve() is called with the allocator
lock held, which covers the race.  In cases where the lock is not
held, GANG_ALLOCATION() or METASLAB_MUST_RESERVE are set, and so we
do not use zfs_refcount_count().  And even if we assume some other
non-existing scenario, the worst that may happen from this race is
few more I/Os get to allocation earlier, that is not a problem.

Move locks and data of different allocators into different cache
lines to avoid false sharing.  Group spa_alloc_* arrays together
into single array of aligned struct spa_alloc spa_allocs.  Align
struct metaslab_class_allocator.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12314
2021-07-21 06:40:36 -06:00
Brian Behlendorf
88a4833039
Update cache file when setting compatibility property
Unlike most other properties the 'compatibility' property is stored
in the pool config object and not the DMU_OT_POOL_PROPS object.

This had the advantage that the compatibility information is available
without needing to fully import the pool (it can be read with zdb).
However, this means we need to make sure to update both the copy of
the config in the MOS and the cache file.  This wasn't being done.

This commit adds a call to spa_async_request() to ensure the copy of
the config in the cache file gets updated as well as the one stored
in the pool.  This same change is made for the 'comment' property
which suffers from the same inconsistency.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Colm Buckley <colm@tuatha.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #12261 
Closes #12276
2021-06-24 14:30:02 -07:00
Rich Ercolani
8e739b2c9f
Annotated dprintf as printf-like
ZFS loves using %llu for uint64_t, but that requires a cast to not 
be noisy - which is even done in many, though not all, places.
Also a couple places used %u for uint64_t, which were promoted
to %llu. 

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #12233
2021-06-22 21:53:45 -07:00
Alexander Motin
29274c9f6d
Optimize small random numbers generation
In all places except two spa_get_random() is used for small values,
and the consumers do not require well seeded high quality values.
Switch those two exceptions directly to random_get_pseudo_bytes()
and optimize spa_get_random(), renaming it to random_in_range(),
since it is not related to SPA or ZFS in general.

On FreeBSD directly map random_in_range() to new prng32_bounded() KPI
added in FreeBSD 13.  On Linux and in user-space just reduce the type
used to uint32_t to avoid more expensive 64bit division.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12183
2021-06-22 17:35:23 -06:00
Alexander Motin
7457b024ba
Scale worker threads and taskqs with number of CPUs
While use of dynamic taskqs allows to reduce number of idle threads,
hardcoded 8 taskqs of each kind is a big overkill for small systems,
complicating CPU scheduling, increasing I/O reorder, etc, while
providing no real locking benefits, just not needed there.

On another side, 12*8 worker threads per kind are able to overload
almost any system nowadays.  For example, pool of several fast SSDs
with SHA256 checksum makes system barely responsive during scrub, or
with dedup enabled barely responsive during large file deletion.

To address both problems this patch introduces ZTI_SCALE macro, alike
to ZTI_BATCH, but with multiple taskqs, depending on number of CPUs,
to be used in places where lock scalability is needed, while request
ordering is not so much.  The code is made to create new taskq for
~6 worker threads (less for small systems, but more for very large)
up to 80% of CPU cores (previous 75% was not good for rounding down).
Both number of threads and threads per taskq are now tunable in case
somebody really wants to use all of system power for ZFS.

While obviously some benchmarks show small peak performance reduction
(not so big really, especially on systems with SMT, where use of the
second threads does not give as much performance as the first ones),
they also show dramatic latency reduction and much more smooth user-
space operation in case of high CPU usage by ZFS.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #11966
2021-05-14 09:13:53 -07:00
pstef
458f82319a
Balance parentheses in parameter descriptions
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Piotr Paweł Stefaniak <pstef@freebsd.org>
Closes #11882
2021-04-11 16:35:07 -07:00
Andrea Gelmini
bf169e9f15 Fix various typos
Correct an assortment of typos throughout the code base.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #11774
2021-04-02 18:52:15 -07:00
Colm
658fb8020f
Add "compatibility" property for zpool feature sets
Property to allow sets of features to be specified; for compatibility
with specific versions / releases / external systems. Influences
the behavior of 'zpool upgrade' and 'zpool create'. Initial man
page changes and test cases included.

Brief synopsis:

zpool create -o compatibility=off|legacy|file[,file...] pool vdev...

compatibility = off : disable compatibility mode (enable all features)
compatibility = legacy : request that no features be enabled
compatibility = file[,file...] : read features from specified files.
Only features present in *all* files will be enabled on the
resulting pool. Filenames may be absolute, or relative to
/etc/zfs/compatibility.d or /usr/share/zfs/compatibility.d (/etc
checked first).

Only affects zpool create, zpool upgrade and zpool status.

ABI changes in libzfs:

* New function "zpool_load_compat" to load and parse compat sets.
* Add "zpool_compat_status_t" typedef for compatibility parse status.
* Add ZPOOL_PROP_COMPATIBILITY to the pool properties enum
* Add ZPOOL_STATUS_COMPATIBILITY_ERR to the pool status enum

An initial set of base compatibility sets are included in
cmd/zpool/compatibility.d, and the Makefile for cmd/zpool is
modified to install these in $pkgdatadir/compatibility.d and to
create symbolic links to a reasonable set of aliases.

Reviewed-by: ericloewe
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Colm Buckley <colm@tuatha.org>
Closes #11468
2021-02-17 21:30:45 -08:00
Will Andrews
f4f50a7048
spa_export_common: refactor common exit points
Create a common exit point for spa_export_common (a very long 
function), which avoids missing steps on failure.  This work
is helpful for the planned forced pool export changes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Will Andrews <will@firepipe.net>
Closes #11514
2021-01-25 15:04:11 -08:00
Matthew Ahrens
aa755b3549
Set aside a metaslab for ZIL blocks
Mixing ZIL and normal allocations has several problems:

1. The ZIL allocations are allocated, written to disk, and then a few
seconds later freed.  This leaves behind holes (free segments) where the
ZIL blocks used to be, which increases fragmentation, which negatively
impacts performance.

2. When under moderate load, ZIL allocations are of 128KB.  If the pool
is fairly fragmented, there may not be many free chunks of that size.
This causes ZFS to load more metaslabs to locate free segments of 128KB
or more.  The loading happens synchronously (from zil_commit()), and can
take around a second even if the metaslab's spacemap is cached in the
ARC.  All concurrent synchronous operations on this filesystem must wait
while the metaslab is loading.  This can cause a significant performance
impact.

3. If the pool is very fragmented, there may be zero free chunks of
128KB or more.  In this case, the ZIL falls back to txg_wait_synced(),
which has an enormous performance impact.

These problems can be eliminated by using a dedicated log device
("slog"), even one with the same performance characteristics as the
normal devices.

This change sets aside one metaslab from each top-level vdev that is
preferentially used for ZIL allocations (vdev_log_mg,
spa_embedded_log_class).  From an allocation perspective, this is
similar to having a dedicated log device, and it eliminates the
above-mentioned performance problems.

Log (ZIL) blocks can be allocated from the following locations.  Each
one is tried in order until the allocation succeeds:
1. dedicated log vdevs, aka "slog" (spa_log_class)
2. embedded slog metaslabs (spa_embedded_log_class)
3. other metaslabs in normal vdevs (spa_normal_class)

The space required for the embedded slog metaslabs is usually between
0.5% and 1.0% of the pool, and comes out of the existing 3.2% of "slop"
space that is not available for user data.

On an all-ssd system with 4TB storage, 87% fragmentation, 60% capacity,
and recordsize=8k, testing shows a ~50% performance increase on random
8k sync writes.  On even more fragmented systems (which hit problem #3
above and call txg_wait_synced()), the performance improvement can be
arbitrarily large (>100x).

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11389
2021-01-21 15:12:54 -08:00
Alexander Motin
f8020c9363
Make metaslab class rotor and aliquot per-allocator.
Metaslab rotor and aliquot are used to distribute workload between
vdevs while keeping some locality for logically adjacent blocks.  Once
multiple allocators were introduced to separate allocation of different
objects it does not make much sense for different allocators to write
into different metaslabs of the same metaslab group (vdev) same time,
competing for its resources.  This change makes each allocator choose
metaslab group independently, colliding with others only sporadically.

Test including simultaneous write into 4 files with recordsize of 4KB
on a striped pool of 30 disks on a system with 40 logical cores show
reduction of vdev queue lock contention from 54 to 27% due to better
load distribution.  Unfortunately it won't help much ZVOLs yet since
only one dataset/ZVOL is synced at a time, and so for the most part
only one allocator is used, but it may improve later.

While there, to reduce the number of pointer dereferences change
per-allocator storage for metaslab classes and groups from several
separate malloc()'s to variable length arrays at the ends of the
original class and group structures.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #11288
2020-12-15 10:55:44 -08:00
Paul Dagnelie
60a4c7d2a2
Implement memory and CPU hotplug
ZFS currently doesn't react to hotplugging cpu or memory into the 
system in any way. This patch changes that by adding logic to the ARC 
that allows the system to take advantage of new memory that is added 
for caching purposes. It also adds logic to the taskq infrastructure 
to support dynamically expanding the number of threads allocated to a 
taskq.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Ahrens <matthew.ahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #11212
2020-12-10 14:09:23 -08:00
Ryan Moeller
0aacde2e9a
FreeBSD: notify userspace when a vdev is removed
This is needed for zfsd to autoreplace vdevs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11260
2020-12-02 10:20:02 -08:00
Brian Behlendorf
b2255edcc0
Distributed Spare (dRAID) Feature
This patch adds a new top-level vdev type called dRAID, which stands
for Distributed parity RAID.  This pool configuration allows all dRAID
vdevs to participate when rebuilding to a distributed hot spare device.
This can substantially reduce the total time required to restore full
parity to pool with a failed device.

A dRAID pool can be created using the new top-level `draid` type.
Like `raidz`, the desired redundancy is specified after the type:
`draid[1,2,3]`.  No additional information is required to create the
pool and reasonable default values will be chosen based on the number
of child vdevs in the dRAID vdev.

    zpool create <pool> draid[1,2,3] <vdevs...>

Unlike raidz, additional optional dRAID configuration values can be
provided as part of the draid type as colon separated values. This
allows administrators to fully specify a layout for either performance
or capacity reasons.  The supported options include:

    zpool create <pool> \
        draid[<parity>][:<data>d][:<children>c][:<spares>s] \
        <vdevs...>

    - draid[parity]       - Parity level (default 1)
    - draid[:<data>d]     - Data devices per group (default 8)
    - draid[:<children>c] - Expected number of child vdevs
    - draid[:<spares>s]   - Distributed hot spares (default 0)

Abbreviated example `zpool status` output for a 68 disk dRAID pool
with two distributed spares using special allocation classes.

```
  pool: tank
 state: ONLINE
config:

    NAME                  STATE     READ WRITE CKSUM
    slag7                 ONLINE       0     0     0
      draid2:8d:68c:2s-0  ONLINE       0     0     0
        L0                ONLINE       0     0     0
        L1                ONLINE       0     0     0
        ...
        U25               ONLINE       0     0     0
        U26               ONLINE       0     0     0
        spare-53          ONLINE       0     0     0
          U27             ONLINE       0     0     0
          draid2-0-0      ONLINE       0     0     0
        U28               ONLINE       0     0     0
        U29               ONLINE       0     0     0
        ...
        U42               ONLINE       0     0     0
        U43               ONLINE       0     0     0
    special
      mirror-1            ONLINE       0     0     0
        L5                ONLINE       0     0     0
        U5                ONLINE       0     0     0
      mirror-2            ONLINE       0     0     0
        L6                ONLINE       0     0     0
        U6                ONLINE       0     0     0
    spares
      draid2-0-0          INUSE     currently in use
      draid2-0-1          AVAIL
```

When adding test coverage for the new dRAID vdev type the following
options were added to the ztest command.  These options are leverages
by zloop.sh to test a wide range of dRAID configurations.

    -K draid|raidz|random - kind of RAID to test
    -D <value>            - dRAID data drives per group
    -S <value>            - dRAID distributed hot spares
    -R <value>            - RAID parity (raidz or dRAID)

The zpool_create, zpool_import, redundancy, replacement and fault
test groups have all been updated provide test coverage for the
dRAID feature.

Co-authored-by: Isaac Huang <he.huang@intel.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Co-authored-by: Don Brady <don.brady@delphix.com>
Co-authored-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mmaybee@cray.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10102
2020-11-13 13:51:51 -08:00
Brian Behlendorf
d0249a4bd0
Replace ZFS on Linux references with OpenZFS
This change updates the documentation to refer to the project
as OpenZFS instead ZFS on Linux.  Web links have been updated
to refer to https://github.com/openzfs/zfs.  The extraneous
zfsonlinux.org web links in the ZED and SPL sources have been
dropped.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11007
2020-10-08 20:10:13 -07:00
Ryan Moeller
4d55ea811d
Throw const on some strings
In C, const indicates to the reader that mutation will not occur.
It can also serve as a hint about ownership.

Add const in a few places where it makes sense.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #10997
2020-10-02 17:44:10 -07:00
George Wilson
c494aa7f57
vdev_ashift should only be set once
== Motivation and Context

The new vdev ashift optimization prevents the removal of devices when
a zfs configuration is comprised of disks which have different logical
and physical block sizes. This is caused because we set 'spa_min_ashift'
in vdev_open and then later call 'vdev_ashift_optimize'. This would
result in an inconsistency between spa's ashift calculations and that
of the top-level vdev.

In addition, the optimization logical ignores the overridden ashift
value that would be provided by '-o ashift=<val>'.

== Description

This change reworks the vdev ashift optimization so that it's only
set the first time the device is configured. It still allows the
physical and logical ahsift values to be set every time the device
is opened but those values are only consulted on first open.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-Issue: DLPX-71831
Closes #10932
2020-09-18 12:13:47 -07:00
Pavel Snajdr
c95625769d Fix stack frame size: spa_livelist_delete_cb()
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes #10879
2020-09-15 15:55:03 -07:00
Matthew Macy
7432d29760
FreeBSD: reduce priority of ZIO_TASKQ_ISSUE writes by a larger value
On FreeBSD, if priorities divided by four (RQ_PPQ) are equal then
a difference between them is insignificant. In other words,
incrementing pri by only one as on Linux is insufficient.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10872
2020-09-04 11:13:27 -07:00
Don Brady
4f07282786
Avoid posting duplicate zpool events
Duplicate io and checksum ereport events can misrepresent that 
things are worse than they seem. Ideally the zpool events and the 
corresponding vdev stat error counts in a zpool status should be 
for unique errors -- not the same error being counted over and over. 
This can be demonstrated in a simple example. With a single bad 
block in a datafile and just 5 reads of the file we end up with a 
degraded vdev, even though there is only one unique error in the pool.

The proposed solution to the above issue, is to eliminate duplicates 
when posting events and when updating vdev error stats. We now save 
recent error events of interest when posting events so that we can 
easily check for duplicates when posting an error. 

Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #10861
2020-09-04 10:34:28 -07:00
Matthew Ahrens
3808032489
nowait synctask must succeed
If a `zfs_space_check_t` other than `ZFS_SPACE_CHECK_NONE` is used with
`dsl_sync_task_nowait()`, the sync task may fail due to ENOSPC.
However, there is no way to notice or communicate this failure, so it's
extremely difficult to use this functionality correctly, and in fact
almost all callers use `ZFS_SPACE_CHECK_NONE`.

This commit removes the `zfs_space_check_t` argument from
`dsl_sync_task_nowait()`, and always uses `ZFS_SPACE_CHECK_NONE`.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10855
2020-09-04 10:29:39 -07:00
Toomas Soome
1144586b57
zio_ereport_post() and zio_ereport_start() return values are ignored
use (void) to silence analyzers.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Toomas Soome <tsoome@me.com>
Closes #10857
2020-08-31 19:35:11 -07:00
Ryan Moeller
a2f944a140
zpool: Change base URL for ZFS messages to openzfs-docs
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10820
2020-08-26 21:43:06 -07:00
Ryan Moeller
6fe3498ca3
Import vdev ashift optimization from FreeBSD
Many modern devices use physical allocation units that are much
larger than the minimum logical allocation size accessible by
external commands. Two prevalent examples of this are 512e disk
drives (512b logical sector, 4K physical sector) and flash devices
(512b logical sector, 4K or larger allocation block size, and 128k
or larger erase block size). Operations that modify less than the
physical sector size result in a costly read-modify-write or garbage
collection sequence on these devices.

Simply exporting the true physical sector of the device to ZFS would
yield optimal performance, but has two serious drawbacks:

 1. Existing pools created with devices that have different logical
    and physical block sizes, but were configured to use the logical
    block size (e.g. because the OS version used for pool construction
    reported the logical block size instead of the physical block
    size) will suddenly find that the vdev allocation size has
    increased. This can be easily tolerated for active members of
    the array, but ZFS would prevent replacement of a vdev with
    another identical device because it now appears that the smaller
    allocation size required by the pool is not supported by the new
    device.

 2. The device's physical block size may be too large to be supported
    by ZFS. The optimal allocation size for the vdev may be quite
    large. For example, a RAID controller may export a vdev that
    requires read-modify-write cycles unless accessed using 64k
    aligned/sized requests. ZFS currently has an 8k minimum block
    size limit.

Reporting both the logical and physical allocation sizes for vdevs
solves these problems. A device may be used so long as the logical
block size is compatible with the configuration. By comparing the
logical and physical block sizes, new configurations can be optimized
and administrators can be notified of any existing pools that are
sub-optimal.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Macy <mmacy@freebsd.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10619
2020-08-21 12:53:17 -07:00
Richard Laager
eaa25f1a8e
Remove GRUB restrictions
The GRUB restrictions are based around the pool's bootfs property.
Given the current situation where GRUB is not staying current with
OpenZFS pool features, having either a non-ZFS /boot or a separate
pool with limited features are pretty much the only long-term answers
for GRUB support.  Only the second case matters in this context.  For
the restrictions to be useful, the bootfs property would have to be set
on the boot pool, because that is where we need the restrictions, as
that is the pool that GRUB reads from. The documentation for bootfs
describes it as pointing to the root pool. That's also how it's used in
the initramfs. ZFS does not allow setting bootfs to point to a dataset
in another pool. (If it did, it'd be difficult-to-impossible to enforce
these restrictions cross-pool). Accordingly, bootfs is pretty much
useless for GRUB scenarios moving forward.

Even for users who have only one pool, the existing restrictions for
GRUB are incomplete. They don't prevent you from enabling the
unsupported checksums, for example. For that reason, I have ripped out
all the GRUB restrictions.

A little longer-term, I think extending the proposed features=portable
system to define a features=grub is a much more useful approach. The
user could set that on the boot pool at creation, and things would
Just Work.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes #8627
2020-08-17 23:12:39 -07:00
Matthew Ahrens
d87676a9fa
Fix i/o error handling of livelists and zap iteration
Pool-wide metadata is stored in the MOS (Meta Object Set).  This
metadata is stored in triplicate, in addition to any pool-level
reduncancy (e.g. RAIDZ).  However, if all 3+ copies of this metadata are
not available, we can still get EIO/ECKSUM when reading from the MOS.
If we encounter such an error in syncing context, we have typically
already committed to making a change that we now can't do because of the
corrupt/missing metadata.  We typically "handle" this with a `VERIFY()`
or `zfs_panic_recover()`.  This prevents the system from continuing on
in an undefined state, while minimizing the amount of error-handling
code.

However, there are some code paths that ignore these i/o errors, or
`ASSERT()` that they don't happen.  Since assertions are disabled on
non-debug builds, they effectively ignore them as well.  This can lead
to ZFS continuing on in an incorrect state, potentially leading to
on-disk inconsistencies.

This commit adds handling for these i/o errors on MOS metadata,
typically with a `VERIFY()`:

* Handle error return from `zap_cursor_retrieve()` in 4 places in
`dsl_deadlist.c`.

* Handle error return from `zap_contains()` in `dsl_dir_hold_obj()`.
Turns out this call isn't necessary because we can always call
`zap_lookup()`.

* Handle error return from `zap_lookup()` in `dsl_fs_ss_limit_check()`.

* Handle error return from `zap_remove()` in `dsl_dir_rename_sync()`.

* Handle error return from `zap_lookup()` in
`dsl_dir_remove_livelist()`.

* Handle error return from `dsl_process_sub_livelist()` in
`spa_livelist_delete_cb()`.

Additionally:

* Augment the internal history log message for `zfs destroy` to note
which method is used (e.g. bptree, livelist, or, synchronous) and the
mintxg.

* Correct a comment in `dbuf_init()`.

* Correct indentation in `dsl_dir_remove_livelist()`.

Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10643
2020-08-05 10:22:09 -07:00
Serapheim Dimitropoulos
843e9ca2e1
Introduce names for ZTHRs
When debugging issues or generally analyzing the runtime of
a system it would be nice to be able to tell the different
ZTHRs running by name rather than having to analyze their
stack.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10630
2020-07-29 09:43:33 -07:00
Alexander Motin
1743c737f5
Fix LOR between dp_config_rwlock and spa_props_lock
Our QE team during automated API testing hit deadlock in ZFS, caused
by lock order reversal.  From one side dsl_sync_task_sync() locks
dp_config_rwlock as writer and calls spa_sync_props(), which waits
for spa_props_lock.  From another spa_prop_get() locks spa_props_lock
and then calls dsl_pool_config_enter(), trying to lock dp_config_rwlock
as reader.

This patch makes spa_prop_get() lock dp_config_rwlock before
spa_props_lock, making the order consistent.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #10553
2020-07-14 12:21:57 -07:00
Brian Behlendorf
9a49d3f3d3
Add device rebuild feature
The device_rebuild feature enables sequential reconstruction when
resilvering.  Mirror vdevs can be rebuilt in LBA order which may
more quickly restore redundancy depending on the pools average block
size, overall fragmentation and the performance characteristics
of the devices.  However, block checksums cannot be verified
as part of the rebuild thus a scrub is automatically started after
the sequential resilver completes.

The new '-s' option has been added to the `zpool attach` and
`zpool replace` command to request sequential reconstruction
instead of healing reconstruction when resilvering.

    zpool attach -s <pool> <existing vdev> <new vdev>
    zpool replace -s <pool> <old vdev> <new vdev>

The `zpool status` output has been updated to report the progress
of sequential resilvering in the same way as healing resilvering.
The one notable difference is that multiple sequential resilvers
may be in progress as long as they're operating on different
top-level vdevs.

The `zpool wait -t resilver` command was extended to wait on
sequential resilvers.  From this perspective they are no different
than healing resilvers.

Sequential resilvers cannot be supported for RAIDZ, but are
compatible with the dRAID feature being developed.

As part of this change the resilver_restart_* tests were moved
in to the functional/replacement directory.  Additionally, the
replacement tests were renamed and extended to verify both
resilvering and rebuilding.

Original-patch-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: John Poduska <jpoduska@datto.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10349
2020-07-03 11:05:50 -07:00
Arvind Sankar
65c7cc49bf Mark functions as static
Mark functions used only in the same translation unit as static. This
only includes functions that do not have a prototype in a header file
either.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470
2020-06-18 12:20:38 -07:00
George Amanakis
b7654bd794
Trim L2ARC
The l2arc_evict() function is responsible for evicting buffers which
reference the next bytes of the L2ARC device to be overwritten. Teach
this function to additionally TRIM that vdev space before it is
overwritten if the device has been filled with data. This is done by
vdev_trim_simple() which trims by issuing a new type of TRIM,
TRIM_TYPE_SIMPLE.

We also implement a "Trim Ahead" feature. It is a zfs module parameter,
expressed in % of the current write size. This trims ahead of the
current write size. A minimum of 64MB will be trimmed. The default is 0
which disables TRIM on L2ARC as it can put significant stress to
underlying storage devices. To enable TRIM on L2ARC we set
l2arc_trim_ahead > 0.

We also implement TRIM of the whole cache device upon addition to a
pool, pool creation or when the header of the device is invalid upon
importing a pool or onlining a cache device. This is dependent on
l2arc_trim_ahead > 0. TRIM of the whole device is done with
TRIM_TYPE_MANUAL so that its status can be monitored by zpool status -t.
We save the TRIM state for the whole device and the time of completion
on-disk in the header, and restore these upon L2ARC rebuild so that
zpool status -t can correctly report them. Whole device TRIM is done
asynchronously so that the user can export of the pool or remove the
cache device while it is trimming (ie if it is too slow).

We do not TRIM the whole device if persistent L2ARC has been disabled by
l2arc_rebuild_enabled = 0 because we may not want to lose all cached
buffers (eg we may want to import the pool with
l2arc_rebuild_enabled = 0 only once because of memory pressure). If
persistent L2ARC has been disabled by setting the module parameter
l2arc_rebuild_blocks_min_l2size to a value greater than the size of the
cache device then the whole device is trimmed upon creation or import of
a pool if l2arc_trim_ahead > 0.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam D. Moss <c@yotes.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #9713
Closes #9789 
Closes #10224
2020-06-09 10:15:08 -07:00
Jorgen Lundman
c9e319faae
Replace sprintf()->snprintf() and strcpy()->strlcpy()
The strcpy() and sprintf() functions are deprecated on some platforms.
Care is needed to ensure correct size is used.  If some platforms
miss snprintf, we can add a #define to sprintf, likewise strlcpy().

The biggest change is adding a size parameter to zfs_id_to_fuidstr().

The various *_impl_get() functions are only used on linux and have
not yet been updated.

Reviewed by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes #10400
2020-06-07 11:42:12 -07:00
George Amanakis
1b664952ae
Enable splitting mirrors with indirect vdevs
When a top-level vdev is removed from a pool it is converted to an
indirect vdev. Until now splitting such mirrored pools was not possible
with zpool split. This patch enables handling of indirect vdevs and
splitting of those pools with zpool split.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10283
2020-05-06 10:32:28 -07:00
Matthew Ahrens
32d805c3e2
Use a struct to organize metaslab-group-allocator fields
Each metaslab group (of which there is one per top-level vdev) has
several (4, by default) "metaslab group allocators".  Each "allocator"
has its own metaslab that it prefers to allocate from (the "primary"
allocator), and each can perform allocations concurrently with the other
allocators.  In addition to the primary metaslab, there are several
other fields that need to be tracked separately for each allocator.
These are currently stored as several arrays in the metaslab_group_t,
each array indexed by allocator number.

This change organizes all the metaslab-group-allocator-specific fields
into a new struct, metaslab_group_allocator_t.  The metaslab_group_t now
needs only one array indexed by the allocator number - which contains
the metaslab_group_allocator_t's.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10213
2020-04-22 10:26:56 -07:00
George Amanakis
77f6826b83
Persistent L2ARC
This commit makes the L2ARC persistent across reboots. We implement
a light-weight persistent L2ARC metadata structure that allows L2ARC
contents to be recovered after a reboot. This significantly eases the
impact a reboot has on read performance on systems with large caches.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Saso Kiselkov <skiselkov@gmail.com>
Co-authored-by: Jorgen Lundman <lundman@lundman.net>
Co-authored-by: George Amanakis <gamanakis@gmail.com>
Ported-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #925 
Closes #1823 
Closes #2672 
Closes #3744 
Closes #9582
2020-04-10 10:33:35 -07:00
Matthew Macy
8b27e08ed8
Add separate field for indicating that spa is in middle of split
By default it's not possible to open a device already owned by an
active vdev. It's necessary to make an exception to this for vdev
split. The FreeBSD platform code will make an exception if
spa_is splitting is set to to true.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10178
2020-04-09 09:59:31 -07:00
Brian Behlendorf
2288d41968
Add trim support to zpool wait
Manual trims fall into the category of long-running pool activities
which people might want to wait synchronously for. This change adds
support to 'zpool wait' for waiting for manual trim operations to
complete. It also adds a '-w' flag to 'zpool trim' which can be used to
turn 'zpool trim' into a synchronous operation.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
Closes #10071
2020-03-04 15:07:11 -08:00
Matthew Ahrens
9cdf7b1f6b
Improve zfs destroy performance with zio_t-free zio_free()
When "zfs destroy" is run, it completes quickly, and in the background
we locate the blocks to free and free them.  This background activity
can be observed with `zpool get freeing` and `zpool wait -t free ...`.

This background activity is processed by a single thread (the spa_sync
thread) which calls zio_free() on each of the blocks to free.  With even
modest storage performance, the CPU consumption of zio_free() can be the
performance bottleneck.

Performance of zio_free() can be improved by not actually creating a
zio_t in the common case (non-dedup, non-gang), instead calling
metaslab_free() directly.  This avoids the CPU cost of allocating the
zio_t, and more importantly the cost of adding and later removing this
zio_t from the parent zio's child list.

The result is that performance of background freeing more than doubles,
from 0.6 million blocks per second to 1.3 million blocks per second.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10034
2020-02-28 14:49:44 -08:00
Matthew Ahrens
ec21397127
async zvol minor node creation interferes with receive
When we finish a zfs receive, dmu_recv_end_sync() calls
zvol_create_minors(async=TRUE).  This kicks off some other threads that
create the minor device nodes (in /dev/zvol/poolname/...).  These async
threads call zvol_prefetch_minors_impl() and zvol_create_minor(), which
both call dmu_objset_own(), which puts a "long hold" on the dataset.
Since the zvol minor node creation is asynchronous, this can happen
after the `ZFS_IOC_RECV[_NEW]` ioctl and `zfs receive` process have
completed.

After the first receive ioctl has completed, userland may attempt to do
another receive into the same dataset (e.g. the next incremental
stream).  This second receive and the asynchronous minor node creation
can interfere with one another in several different ways, because they
both require exclusive access to the dataset:

1. When the second receive is finishing up, dmu_recv_end_check() does
dsl_dataset_handoff_check(), which can fail with EBUSY if the async
minor node creation already has a "long hold" on this dataset.  This
causes the 2nd receive to fail.

2. The async udev rule can fail if zvol_id and/or systemd-udevd try to
open the device while the the second receive's async attempt at minor
node creation owns the dataset (via zvol_prefetch_minors_impl).  This
causes the minor node (/dev/zd*) to exist, but the udev-generated
/dev/zvol/... to not exist.

3. The async minor node creation can silently fail with EBUSY if the
first receive's zvol_create_minor() trys to own the dataset while the
second receive's zvol_prefetch_minors_impl already owns the dataset.

To address these problems, this change synchronously creates the minor
node.  To avoid the lock ordering problems that the asynchrony was
introduced to fix (see #3681), we create the minor nodes from open
context, with no locks held, rather than from syncing contex as was
originally done.

Implementation notes:

We generally do not need to traverse children or prefetch anything (e.g.
when running the recv, snapshot, create, or clone subcommands of zfs).
We only need recursion when importing/opening a pool and when loading
encryption keys.  The existing recursive, asynchronous, prefetching code
is preserved for use in these cases.

Channel programs may need to create zvol minor nodes, when creating a
snapshot of a zvol with the snapdev property set.  We figure out what
snapshots are created when running the LUA program in syncing context.
In this case we need to remember what snapshots were created, and then
try to create their minor nodes from open context, after the LUA code
has completed.

There are additional zvol use cases that asynchronously own the dataset,
which can cause similar problems.  E.g. changing the volmode or snapdev
properties.  These are less problematic because they are not recursive
and don't touch datasets that are not involved in the operation, there
is still potential for interference with subsequent operations.  In the
future, these cases should be similarly converted to create the zvol
minor node synchronously from open context.

The async tasks of removing and renaming minors do not own the objset,
so they do not have this problem.  However, it may make sense to also
convert these operations to happen synchronously from open context, in
the future.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-65948
Closes #7863
Closes #9885
2020-02-03 09:33:14 -08:00
loli10K
c24fa4b19a Fix "zpool add -n" for dedup, special and log devices
For dedup, special and log devices "zpool add -n" does not print
correctly their vdev type:

~# zpool add -n pool dedup /tmp/dedup special /tmp/special log /tmp/log
would update 'pool' to the following configuration:
	pool
	  /tmp/normal
	  /tmp/dedup
	  /tmp/special
	  /tmp/log

This could lead storage administrators to modify their ZFS pools to
unexpected and unintended vdev configurations.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #9783 
Closes #9390
2020-01-06 15:40:06 -08:00
Matthew Macy
2a8ba608d3 Replace ASSERTV macro with compiler annotation
Remove the ASSERTV macro and handle suppressing unused 
compiler warnings for variables only in ASSERTs using the 
__attribute__((unused)) compiler annotation.  The annotation
is understood by both gcc and clang.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9671
2019-12-05 12:37:00 -08:00
jwpoduska
3c819a2c7d Prevent unnecessary resilver restarts
If a device is participating in an active resilver, then it will have a
non-empty DTL. Operations like vdev_{open,reopen,probe}() can cause the
resilver to be restarted (or deferred to be restarted later), which is
unnecessary if the DTL is still covered by the current scan range. This
is similar to the logic in vdev_dtl_should_excise() where the DTL can
only be excised if it's max txg is in the resilvered range.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Signed-off-by: John Poduska <jpoduska@datto.com>
Issue #840 
Closes #9155
Closes #9378
Closes #9551
Closes #9588
2019-11-27 10:15:01 -08:00
Matthew Macy
da92d5cbb3 Add zfs_file_* interface, remove vnodes
Provide a common zfs_file_* interface which can be implemented on all 
platforms to perform normal file access from either the kernel module
or the libzpool library.

This allows all non-portable vnode_t usage in the common code to be 
replaced by the new portable zfs_file_t.  The associated vnode and
kobj compatibility functions, types, and macros have been removed
from the SPL.  Moving forward, vnodes should only be used in platform
specific code when provided by the native operating system.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9556
2019-11-21 09:32:57 -08:00
Matthew Macy
4a22ba5be0 Minor spa portability fixes
- FreeBSD's rootpool import code uses spa_config_parse
- Move the zvol_create_minors call out from under the
  spa_namespace_lock in spa_import. It isn't needed and it causes
  a lock order reversal on FreeBSD.

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9499
2019-10-28 09:51:53 -07:00
loli10K
715c996d3b Fix pool creation with feature@allocation_classes disabled
When "feature@allocation_classes" is not enabled on the pool no vdev
with "special" or "dedup" allocation type should be allowed to exist in
the vdev tree.

Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #9427 
Closes #9429
2019-10-10 16:39:41 -07:00
Paul Dagnelie
ca5777793e Reduce loaded range tree memory usage
This patch implements a new tree structure for ZFS, and uses it to 
store range trees more efficiently.

The new structure is approximately a B-tree, though there are some 
small differences from the usual characterizations. The tree has core 
nodes and leaf nodes; each contain data elements, which the elements 
in the core nodes acting as separators between its children. The 
difference between core and leaf nodes is that the core nodes have an 
array of children, while leaf nodes don't. Every node in the tree may 
be only partially full; in most cases, they are all at least 50% full 
(in terms of element count) except for the root node, which can be 
less full. Underfull nodes will steal from their neighbors or merge to 
remain full enough, while overfull nodes will split in two. The data 
elements are contained in tree-controlled buffers; they are copied 
into these on insertion, and overwritten on deletion. This means that 
the elements are not independently allocated, which reduces overhead, 
but also means they can't be shared between trees (and also that 
pointers to them are only valid until a side-effectful tree operation 
occurs). The overhead varies based on how dense the tree is, but is 
usually on the order of about 50% of the element size; the per-node 
overheads are very small, and so don't make a significant difference. 
The trees can accept arbitrary records; they accept a size and a 
comparator to allow them to be used for a variety of purposes.

The new trees replace the AVL trees used in the range trees today. 
Currently, the range_seg_t structure contains three 8 byte integers 
of payload and two 24 byte avl_tree_node_ts to handle its storage in 
both an offset-sorted tree and a size-sorted tree (total size: 64 
bytes). In the new model, the range seg structures are usually two 4 
byte integers, but a separate one needs to exist for the size-sorted 
and offset-sorted tree. Between the raw size, the 50% overhead, and 
the double storage, the new btrees are expected to use 8*1.5*2 = 24 
bytes per record, or 33.3% as much memory as the AVL trees (this is 
for the purposes of storing metaslab range trees; for other purposes, 
like scrubs, they use ~50% as much memory).

We reduced the size of the payload in the range segments by teaching 
range trees about starting offsets and shifts; since metaslabs have a 
fixed starting offset, and they all operate in terms of disk sectors, 
we can store the ranges using 4-byte integers as long as the size of 
the metaslab divided by the sector size is less than 2^32. For 512-byte
sectors, this is a 2^41 (or 2TB) metaslab, which with the default
settings corresponds to a 256PB disk. 4k sector disks can handle 
metaslabs up to 2^46 bytes, or 2^63 byte disks. Since we do not 
anticipate disks of this size in the near future, there should be 
almost no cases where metaslabs need 64-byte integers to store their 
ranges. We do still have the capability to store 64-byte integer ranges 
to account for cases where we are storing per-vdev (or per-dnode) trees, 
which could reasonably go above the limits discussed. We also do not 
store fill information in the compact version of the node, since it 
is only used for sorted scrub.

We also optimized the metaslab loading process in various other ways
to offset some inefficiencies in the btree model. While individual
operations (find, insert, remove_from) are faster for the btree than 
they are for the avl tree, remove usually requires a find operation, 
while in the AVL tree model the element itself suffices. Some clever 
changes actually caused an overall speedup in metaslab loading; we use 
approximately 40% less cpu to load metaslabs in our tests on Illumos.

Another memory and performance optimization was achieved by changing 
what is stored in the size-sorted trees. When a disk is heavily 
fragmented, the df algorithm used by default in ZFS will almost always 
find a number of small regions in its initial cursor-based search; it 
will usually only fall back to the size-sorted tree to find larger 
regions. If we increase the size of the cursor-based search slightly, 
and don't store segments that are smaller than a tunable size floor 
in the size-sorted tree, we can further cut memory usage down to 
below 20% of what the AVL trees store. This also results in further 
reductions in CPU time spent loading metaslabs.

The 16KiB size floor was chosen because it results in substantial memory 
usage reduction while not usually resulting in situations where we can't 
find an appropriate chunk with the cursor and are forced to use an 
oversized chunk from the size-sorted tree. In addition, even if we do 
have to use an oversized chunk from the size-sorted tree, the chunk 
would be too small to use for ZIL allocations, so it isn't as big of a 
loss as it might otherwise be. And often, more small allocations will 
follow the initial one, and the cursor search will now find the 
remainder of the chunk we didn't use all of and use it for subsequent 
allocations. Practical testing has shown little or no change in 
fragmentation as a result of this change.

If the size-sorted tree becomes empty while the offset sorted one still 
has entries, it will load all the entries from the offset sorted tree 
and disregard the size floor until it is unloaded again. This operation 
occurs rarely with the default setting, only on incredibly thoroughly 
fragmented pools.

There are some other small changes to zdb to teach it to handle btrees, 
but nothing major.
                                           
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed by: Sebastien Roy seb@delphix.com
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #9181
2019-10-09 10:36:03 -07:00
loli10K
b24771a8c9 Prevent gcc -Werror=maybe-uninitialized warnings in spa_wait_common()
This commit fixes the following build failure detected on Debian9
(GCC 6.3.0):

     CC [M]  module/zfs/spa.o
   module/zfs/spa.c: In function ‘spa_wait_common.part.31’:
   module/zfs/spa.c:9468:6: error: ‘in_progress’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
      if (!in_progress || spa->spa_waiters_cancel || error)
         ^
   cc1: all warnings being treated as errors

Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #9326
2019-09-16 10:46:02 -07:00
John Gallagher
e60e158eff Add subcommand to wait for background zfs activity to complete
Currently the best way to wait for the completion of a long-running
operation in a pool, like a scrub or device removal, is to poll 'zpool
status' and parse its output, which is neither efficient nor convenient.

This change adds a 'wait' subcommand to the zpool command. When invoked,
'zpool wait' will block until a specified type of background activity
completes. Currently, this subcommand can wait for any of the following:

 - Scrubs or resilvers to complete
 - Devices to initialized
 - Devices to be replaced
 - Devices to be removed
 - Checkpoints to be discarded
 - Background freeing to complete

For example, a scrub that is in progress could be waited for by running

    zpool wait -t scrub <pool>

This also adds a -w flag to the attach, checkpoint, initialize, replace,
remove, and scrub subcommands. When used, this flag makes the operations
kicked off by these subcommands synchronous instead of asynchronous.

This functionality is implemented using a new ioctl. The type of
activity to wait for is provided as input to the ioctl, and the ioctl
blocks until all activity of that type has completed. An ioctl was used
over other methods of kernel-userspace communiction primarily for the
sake of portability.

Porting Notes:
This is ported from Delphix OS change DLPX-44432. The following changes
were made while porting:

 - Added ZoL-style ioctl input declaration.
 - Reorganized error handling in zpool_initialize in libzfs to integrate
   better with changes made for TRIM support.
 - Fixed check for whether a checkpoint discard is in progress.
   Previously it also waited if the pool had a checkpoint, instead of
   just if a checkpoint was being discarded.
 - Exposed zfs_initialize_chunk_size as a ZoL-style tunable.
 - Updated more existing tests to make use of new 'zpool wait'
   functionality, tests that don't exist in Delphix OS.
 - Used existing ZoL tunable zfs_scan_suspend_progress, together with
   zinject, in place of a new tunable zfs_scan_max_blks_per_txg.
 - Added support for a non-integral interval argument to zpool wait.

Future work:
ZoL has support for trimming devices, which Delphix OS does not. In the
future, 'zpool wait' could be extended to add the ability to wait for
trim operations to complete.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
Closes #9162
2019-09-13 18:09:06 -07:00
Matthew Macy
74756182d2 Enable compiler to typecheck logging
Annotate spa logging declarations with printflike
Workaround gcc bug (non disable-able warning) by
replacing "" with " "

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9316
2019-09-12 13:28:26 -07:00
Brian Behlendorf
25f06d677a
Fix /etc/hostid on root pool deadlock
Accidentally introduced by dc04a8c which now takes the SCL_VDEV lock
as a reader in zfs_blkptr_verify().  A deadlock can occur if the
/etc/hostid file resides on a dataset in the same pool.  This is
because reading the /etc/hostid file may occur while the caller is
holding the SCL_VDEV lock as a writer.  For example, to perform a
`zpool attach` as shown in the abbreviated stack below.

To resolve the issue we cache the system's hostid when initializing
the spa_t, or when modifying the multihost property.  The cached
value is then relied upon for subsequent accesses.

Call Trace:
    spa_config_enter+0x1e8/0x350 [zfs]
    zfs_blkptr_verify+0x33c/0x4f0 [zfs] <--- trying read lock
    zio_read+0x6c/0x140 [zfs]
    ...
    vfs_read+0xfc/0x1e0
    kernel_read+0x50/0x90
    ...
    spa_get_hostid+0x1c/0x38 [zfs]
    spa_config_generate+0x1a0/0x610 [zfs]
    vdev_label_init+0xa0/0xc80 [zfs]
    vdev_create+0x98/0xe0 [zfs]
    spa_vdev_attach+0x14c/0xb40 [zfs] <--- grabbed write lock

Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9256 
Closes #9285
2019-09-10 13:42:30 -07:00
Matthew Macy
03fdcb9adc Make module tunables cross platform
Adds ZFS_MODULE_PARAM to abstract module parameter
setting to operating systems other than Linux.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes #9230
2019-09-05 14:49:49 -07:00
George Wilson
1e52716257 maxinflight can overflow in spa_load_verify_cb()
When running on larger memory systems, we can overflow the value of
maxinflight. This can result in maxinflight having a value of 0 causing
the system to hang.

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes #9272
2019-09-02 19:17:51 -07:00
Andrea Gelmini
e1cfd73f7f Fix typos in module/zfs/
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #9240
2019-09-02 17:56:41 -07:00
Paul Dagnelie
f09fda5071 Cap metaslab memory usage
On systems with large amounts of storage and high fragmentation, a huge 
amount of space can be used by storing metaslab range trees. Since 
metaslabs are only unloaded during a txg sync, and only if they have 
been inactive for 8 txgs, it is possible to get into a state where all 
of the system's memory is consumed by range trees and metaslabs, and 
txgs cannot sync. While ZFS knows how to evict ARC data when needed, 
it has no such mechanism for range tree data. This can result in boot 
hangs for some system configurations.

First, we add the ability to unload metaslabs outside of syncing 
context. Second, we store a multilist of all loaded metaslabs, sorted 
by their selection txg, so we can quickly identify the oldest 
metaslabs.  We use a multilist to reduce lock contention during heavy 
write workloads. Finally, we add logic that will unload a metaslab 
when we're loading a new metaslab, if we're using more than a certain 
fraction of the available memory on range trees.

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #9128
2019-08-16 09:08:21 -06:00
George Wilson
c8242a96ba spa_load_verify() may consume too much memory
When a pool is imported it will scan the pool to verify the integrity 
of the data and metadata. The amount it scans will depend on the 
import flags provided. On systems with small amounts of memory or 
when importing a pool from the crash kernel, it's possible for 
spa_load_verify to issue too many I/Os that it consumes all the memory 
of the system resulting in an OOM message or a hang.

To prevent this, we limit the amount of memory that the initial pool
scan can consume. This change will, by default, use 1/16th of the ARC
for scan I/Os to prevent running the system out of memory during import.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: George Wilson george.wilson@delphix.com
External-issue: DLPX-65237
External-issue: DLPX-65238
Closes #9146
2019-08-13 08:11:57 -06:00
Sara Hartse
37f03da8ba Fast Clone Deletion
Deleting a clone requires finding blocks are clone-only, not shared
with the snapshot. This was done by traversing the entire block tree
which results in a large performance penalty for sparsely
written clones.

This is new method keeps track of clone blocks when they are
modified in a "Livelist" so that, when it’s time to delete,
the clone-specific blocks are already at hand.

We see performance improvements because now deletion work is
proportional to the number of clone-modified blocks, not the size
of the original dataset.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Sara Hartse <sara.hartse@delphix.com>
Closes #8416
2019-07-26 10:54:14 -07:00
Serapheim Dimitropoulos
43a8536260 Race condition between spa async threads and export
In the past we've seen multiple race conditions that have
to do with open-context threads async threads and concurrent
calls to spa_export()/spa_destroy() (including the one
referenced in issue #9015).

This patch ensures that only one thread can execute the
main body of spa_export_common() at a time, with subsequent
threads returning with a new error code created just for
this situation, eliminating this way any race condition
bugs introduced by concurrent calls to this function.

Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #9015 
Closes #9044
2019-07-18 13:02:33 -07:00
Serapheim Dimitropoulos
93e28d661e Log Spacemap Project
= Motivation

At Delphix we've seen a lot of customer systems where fragmentation
is over 75% and random writes take a performance hit because a lot
of time is spend on I/Os that update on-disk space accounting metadata.
Specifically, we seen cases where 20% to 40% of sync time is spend
after sync pass 1 and ~30% of the I/Os on the system is spent updating
spacemaps.

The problem is that these pools have existed long enough that we've
touched almost every metaslab at least once, and random writes
scatter frees across all metaslabs every TXG, thus appending to
their spacemaps and resulting in many I/Os. To give an example,
assuming that every VDEV has 200 metaslabs and our writes fit within
a single spacemap block (generally 4K) we have 200 I/Os. Then if we
assume 2 levels of indirection, we need 400 additional I/Os and
since we are talking about metadata for which we keep 2 extra copies
for redundancy we need to triple that number, leading to a total of
1800 I/Os per VDEV every TXG.

We could try and decrease the number of metaslabs so we have less
I/Os per TXG but then each metaslab would cover a wider range on
disk and thus would take more time to be loaded in memory from disk.
In addition, after it's loaded, it's range tree would consume more
memory.

Another idea would be to just increase the spacemap block size
which would allow us to fit more entries within an I/O block
resulting in fewer I/Os per metaslab and a speedup in loading time.
The problem is still that we don't deal with the number of I/Os
going up as the number of metaslabs is increasing and the fact
is that we generally write a lot to a few metaslabs and a little
to the rest of them. Thus, just increasing the block size would
actually waste bandwidth because we won't be utilizing our bigger
block size.

= About this patch

This patch introduces the Log Spacemap project which provides the
solution to the above problem while taking into account all the
aforementioned tradeoffs. The details on how it achieves that can
be found in the references sections below and in the code (see
Big Theory Statement in spa_log_spacemap.c).

Even though the change is fairly constraint within the metaslab
and lower-level SPA codepaths, there is a side-change that is
user-facing. The change is that VDEV IDs from VDEV holes will no
longer be reused. To give some background and reasoning for this,
when a log device is removed and its VDEV structure was replaced
with a hole (or was compacted; if at the end of the vdev array),
its vdev_id could be reused by devices added after that. Now
with the pool-wide space maps recording the vdev ID, this behavior
can cause problems (e.g. is this entry referring to a segment in
the new vdev or the removed log?). Thus, to simplify things the
ID reuse behavior is gone and now vdev IDs for top-level vdevs
are truly unique within a pool.

= Testing

The illumos implementation of this feature has been used internally
for a year and has been in production for ~6 months. For this patch
specifically there don't seem to be any regressions introduced to
ZTS and I have been running zloop for a week without any related
problems.

= Performance Analysis (Linux Specific)

All performance results and analysis for illumos can be found in
the links of the references. Redoing the same experiments in Linux
gave similar results. Below are the specifics of the Linux run.

After the pool reached stable state the percentage of the time
spent in pass 1 per TXG was 64% on average for the stock bits
while the log spacemap bits stayed at 95% during the experiment
(graph: sdimitro.github.io/img/linux-lsm/PercOfSyncInPassOne.png).

Sync times per TXG were 37.6 seconds on average for the stock
bits and 22.7 seconds for the log spacemap bits (related graph:
sdimitro.github.io/img/linux-lsm/SyncTimePerTXG.png). As a result
the log spacemap bits were able to push more TXGs, which is also
the reason why all graphs quantified per TXG have more entries for
the log spacemap bits.

Another interesting aspect in terms of txg syncs is that the stock
bits had 22% of their TXGs reach sync pass 7, 55% reach sync pass 8,
and 20% reach 9. The log space map bits reached sync pass 4 in 79%
of their TXGs, sync pass 7 in 19%, and sync pass 8 at 1%. This
emphasizes the fact that not only we spend less time on metadata
but we also iterate less times to convergence in spa_sync() dirtying
objects.
[related graphs:
stock- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGStock.png
lsm- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGLSM.png]

Finally, the improvement in IOPs that the userland gains from the
change is approximately 40%. There is a consistent win in IOPS as
you can see from the graphs below but the absolute amount of
improvement that the log spacemap gives varies within each minute
interval.
sdimitro.github.io/img/linux-lsm/StockVsLog3Days.png
sdimitro.github.io/img/linux-lsm/StockVsLog10Hours.png

= Porting to Other Platforms

For people that want to port this commit to other platforms below
is a list of ZoL commits that this patch depends on:

Make zdb results for checkpoint tests consistent
db587941c5

Update vdev_is_spacemap_addressable() for new spacemap encoding
419ba59145

Simplify spa_sync by breaking it up to smaller functions
8dc2197b7b

Factor metaslab_load_wait() in metaslab_load()
b194fab0fb

Rename range_tree_verify to range_tree_verify_not_present
df72b8bebe

Change target size of metaslabs from 256GB to 16GB
c853f382db

zdb -L should skip leak detection altogether
21e7cf5da8

vs_alloc can underflow in L2ARC vdevs
7558997d2f

Simplify log vdev removal code
6c926f426a

Get rid of space_map_update() for ms_synced_length
425d3237ee

Introduce auxiliary metaslab histograms
928e8ad47d

Error path in metaslab_load_impl() forgets to drop ms_sync_lock
8eef997679

= References

Background, Motivation, and Internals of the Feature
- OpenZFS 2017 Presentation:
youtu.be/jj2IxRkl5bQ
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemaps-project

Flushing Algorithm Internals & Performance Results
(Illumos Specific)
- Blogpost:
sdimitro.github.io/post/zfs-lsm-flushing/
- OpenZFS 2018 Presentation:
youtu.be/x6D2dHRjkxw
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemap-flushing-algorithm

Upstream Delphix Issues:
DLPX-51539, DLPX-59659, DLPX-57783, DLPX-61438, DLPX-41227, DLPX-59320
DLPX-63385

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8442
2019-07-16 10:11:49 -07:00
Matthew Ahrens
050d720c43 Remove dedupditto functionality
If dedup is in use, the `dedupditto` property can be set, causing ZFS to
keep an extra copy of data that is referenced many times (>100x).  The
idea was that this data is more important than other data and thus we
want to be really sure that it is not lost if the disk experiences a
small amount of random corruption.

ZFS (and system administrators) rely on the pool-level redundancy to
protect their data (e.g. mirroring or RAIDZ).  Since the user/sysadmin
doesn't have control over what data will be offered extra redundancy by
dedupditto, this extra redundancy is not very useful.  The bulk of the
data is still vulnerable to loss based on the pool-level redundancy.
For example, if particle strikes corrupt 0.1% of blocks, you will either
be saved by mirror/raidz, or you will be sad.  This is true even if
dedupditto saved another 0.01% of blocks from being corrupted.

Therefore, the dedupditto functionality is rarely enabled (i.e. the
property is rarely set), and it fulfills its promise of increased
redundancy even more rarely.

Additionally, this feature does not work as advertised (on existing
releases), because scrub/resilver did not repair the extra (dedupditto)
copy (see https://github.com/zfsonlinux/zfs/pull/8270).

In summary, this seldom-used feature doesn't work, and even if it did it
wouldn't provide useful data protection.  It has a non-trivial
maintenance burden (again see https://github.com/zfsonlinux/zfs/pull/8270).

We should remove the dedupditto functionality.  For backwards
compatibility with the existing CLI, "zpool set dedupditto" will still
"succeed" (exit code zero), but won't have any effect.  For backwards
compatibility with existing pools that had dedupditto enabled at some
point, the code will still be able to understand dedupditto blocks and
free them when appropriate.  However, ZFS won't write any new dedupditto
blocks.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Issue #8270 
Closes #8310
2019-06-19 14:54:02 -07:00
Paul Dagnelie
30af21b025 Implement Redacted Send/Receive
Redacted send/receive allows users to send subsets of their data to 
a target system. One possible use case for this feature is to not 
transmit sensitive information to a data warehousing, test/dev, or 
analytics environment. Another is to save space by not replicating 
unimportant data within a given dataset, for example in backup tools 
like zrepl.

Redacted send/receive is a three-stage process. First, a clone (or 
clones) is made of the snapshot to be sent to the target. In this 
clone (or clones), all unnecessary or unwanted data is removed or
modified. This clone is then snapshotted to create the "redaction 
snapshot" (or snapshots). Second, the new zfs redact command is used 
to create a redaction bookmark. The redaction bookmark stores the 
list of blocks in a snapshot that were modified by the redaction 
snapshot(s). Finally, the redaction bookmark is passed as a parameter 
to zfs send. When sending to the snapshot that was redacted, the
redaction bookmark is used to filter out blocks that contain sensitive 
or unwanted information, and those blocks are not included in the send 
stream.  When sending from the redaction bookmark, the blocks it 
contains are considered as candidate blocks in addition to those 
blocks in the destination snapshot that were modified since the 
creation_txg of the redaction bookmark.  This step is necessary to 
allow the target to rehydrate data in the case where some blocks are 
accidentally or unnecessarily modified in the redaction snapshot.

The changes to bookmarks to enable fast space estimation involve 
adding deadlists to bookmarks. There is also logic to manage the 
life cycles of these deadlists.

The new size estimation process operates in cases where previously 
an accurate estimate could not be provided. In those cases, a send 
is performed where no data blocks are read, reducing the runtime 
significantly and providing a byte-accurate size estimate.

Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Chris Williamson <chris.williamson@delphix.com>
Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #7958
2019-06-19 09:48:12 -07:00
Olaf Faaland
ca95f70dff zpool import progress kstat
When an import requires a long MMP activity check, or when the user
requests pool recovery, the import make take a long time.  The user may
not know why, or be able to tell whether the import is progressing or is
hung.

Add a kstat which lists all imports currently being processed by the
kernel (currently only one at a time is possible, but the kstat allows
for more than one).  The kstat is /proc/spl/kstat/zfs/import_progress.

The kstat contents are as follows:
pool_guid         load_state multihost_secs  max_txg pool_name
16667015954387398 3          15              0       tank3

load_state: the value of spa_load_state
multihost_secs:  seconds until the end of the multihost activity
                 check; if over, or none required, this is 0
max_txg: current spa_load_max_txg, if rewind is occurring

This could be used by outside tools, such as a pacemaker resource agent,
to report import progress, or as a part of manual troubleshooting.  The
zpool import subcommand could also be modified to report this
information.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #8696
2019-05-09 10:08:05 -07:00
Tom Caputi
fa24166074 Add feature check for 'zpool resilver' command
The 'zpool resilver' command requires that the resilver_defer
feature is active on the pool. Unfortunately, the check for
this was left out of the original patch. This commit simply
corrects this so that the command properly returns an error
in this case.

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8700
2019-05-02 16:42:31 -07:00
Richard Laager
fcf21f8fcb Update a comment to match the code
GRUB supports large_blocks.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes #8626
2019-04-16 10:02:33 -07:00
Matthew Ahrens
944a37248a predictive prefetch disabled on new pools until export/reboot
When a pool is initially created (by `zpool create`), predictive
prefetch is inadvertently disabled, until the pool is export/import-ed,
or the machine is rebooted.

When device removal was introduced, we added some code to disable
predictive prefetching until indirect vdevs have been loaded.  This
resulted in the "default state" of prefetch being disabled, until we
proactively enable it after indirect vdevs are loaded.  Unfortunately
this resulted in a few bugs where in some code paths we neglect to
enable predictive prefetch.  The first of these was fixed by
20507534d4

This commit fixes another case where we also need to explicitly enable
predictive prefetch, when the pool is initially created.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #8577
2019-04-05 10:12:02 -07:00
Brian Behlendorf
1b939560be
Add TRIM support
UNMAP/TRIM support is a frequently-requested feature to help
prevent performance from degrading on SSDs and on various other
SAN-like storage back-ends.  By issuing UNMAP/TRIM commands for
sectors which are no longer allocated the underlying device can
often more efficiently manage itself.

This TRIM implementation is modeled on the `zpool initialize`
feature which writes a pattern to all unallocated space in the
pool.  The new `zpool trim` command uses the same vdev_xlate()
code to calculate what sectors are unallocated, the same per-
vdev TRIM thread model and locking, and the same basic CLI for
a consistent user experience.  The core difference is that
instead of writing a pattern it will issue UNMAP/TRIM commands
for those extents.

The zio pipeline was updated to accommodate this by adding a new
ZIO_TYPE_TRIM type and associated spa taskq.  This new type makes
is straight forward to add the platform specific TRIM/UNMAP calls
to vdev_disk.c and vdev_file.c.  These new ZIO_TYPE_TRIM zios are
handled largely the same way as ZIO_TYPE_READs or ZIO_TYPE_WRITEs.
This makes it possible to largely avoid changing the pipieline,
one exception is that TRIM zio's may exceed the 16M block size
limit since they contain no data.

In addition to the manual `zpool trim` command, a background
automatic TRIM was added and is controlled by the 'autotrim'
property.  It relies on the exact same infrastructure as the
manual TRIM.  However, instead of relying on the extents in a
metaslab's ms_allocatable range tree, a ms_trim tree is kept
per metaslab.  When 'autotrim=on', ranges added back to the
ms_allocatable tree are also added to the ms_free tree.  The
ms_free tree is then periodically consumed by an autotrim
thread which systematically walks a top level vdev's metaslabs.

Since the automatic TRIM will skip ranges it considers too small
there is value in occasionally running a full `zpool trim`.  This
may occur when the freed blocks are small and not enough time
was allowed to aggregate them.  An automatic TRIM and a manual
`zpool trim` may be run concurrently, in which case the automatic
TRIM will yield to the manual TRIM.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Contributions-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Contributions-by: Tim Chase <tim@chase2k.com>
Contributions-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8419 
Closes #598
2019-03-29 09:13:20 -07:00
Roman Strashkin
234234ca4d Panic when running 'zpool split'
Added missing remove of detachable VDEV from txg's DTL list
to avoid use-after-free for the split VDEV

Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Closes #5565 
Closes #7856
2019-03-22 13:11:36 -07:00
Olaf Faaland
060f0226e6 MMP interval and fail_intervals in uberblock
When Multihost is enabled, and a pool is imported, uberblock writes
include ub_mmp_delay to allow an importing node to calculate the
duration of an activity test.  This value, is not enough information.

If zfs_multihost_fail_intervals > 0 on the node with the pool imported,
the safe minimum duration of the activity test is well defined, but does
not depend on ub_mmp_delay:

zfs_multihost_fail_intervals * zfs_multihost_interval

and if zfs_multihost_fail_intervals == 0 on that node, there is no such
well defined safe duration, but the importing host cannot tell whether
mmp_delay is high due to I/O delays, or due to a very large
zfs_multihost_interval setting on the host which last imported the pool.
As a result, it may use a far longer period for the activity test than
is necessary.

This patch renames ub_mmp_sequence to ub_mmp_config and uses it to
record the zfs_multihost_interval and zfs_multihost_fail_intervals
values, as well as the mmp sequence.  This allows a shorter activity
test duration to be calculated by the importing host in most situations.
These values are also added to the multihost_history kstat records.

It calculates the activity test duration differently depending on
whether the new fields are present or not; for importing pools with
only ub_mmp_delay, it uses

(zfs_multihost_interval + ub_mmp_delay) * zfs_multihost_import_intervals

Which results in an activity test duration less sensitive to the leaf
count.

In addition, it makes a few other improvements:
* It updates the "sequence" part of ub_mmp_config when MMP writes
  in between syncs occur.  This allows an importing host to detect MMP
  on the remote host sooner, when the pool is idle, as it is not limited
  to the granularity of ub_timestamp (1 second).
* It issues writes immediately when zfs_multihost_interval is changed
  so remote hosts see the updated value as soon as possible.
* It fixes a bug where setting zfs_multihost_fail_intervals = 1 results
  in immediate pool suspension.
* Update tests to verify activity check duration is based on recorded
  tunable values, not tunable values on importing host.
* Update tests to verify the expected number of uberblocks have valid
  MMP fields - fail_intervals, mmp_interval, mmp_seq (sequence number),
  that sequence number is incrementing, and that uberblock values match
  tunable settings.

Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #7842
2019-03-21 12:47:57 -07:00
Tom Caputi
f00ab3f22c Detect and prevent mixed raw and non-raw sends
Currently, there is an issue in the raw receive code where
raw receives are allowed to happen on top of previously
non-raw received datasets. This is a problem because the
source-side dataset doesn't know about how the blocks on
the destination were encrypted. As a result, any MAC in
the objset's checksum-of-MACs tree that is a parent of both
blocks encrypted on the source and blocks encrypted by the
destination will be incorrect. This will result in
authentication errors when we decrypt the dataset.

This patch fixes this issue by adding a new check to the
raw receive code. The code now maintains an "IVset guid",
which acts as an identifier for the set of IVs used to
encrypt a given snapshot. When a snapshot is raw received,
the destination snapshot will take this value from the
DRR_BEGIN payload. Non-raw receives and normal "zfs snap"
operations will cause ZFS to generate a new IVset guid.
When a raw incremental stream is received, ZFS will check
that the "from" IVset guid in the stream matches that of
the "from" destination snapshot. If they do not match, the
code will error out the receive, preventing the problem.

This patch requires an on-disk format change to add the
IVset guids to snapshots and bookmarks. As a result, this
patch has errata handling and a tunable to help affected
users resolve the issue with as little interruption as
possible.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8308
2019-03-13 11:00:43 -07:00
Serapheim Dimitropoulos
8dc2197b7b Simplify spa_sync by breaking it up to smaller functions
The point of this refactoring is to break the high-level conceptual 
steps of spa_sync() to their own helper functions. In general large 
functions can enhance readability if structured well, but in this
case the amount of conceptual steps taken could use the help of 
helper functions.

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8293
2019-01-18 09:50:16 -08:00
Serapheim Dimitropoulos
61c3391acc Serialize ZTHR operations to eliminate races
Adds a new lock for serializing operations on zthrs.
The commit also includes some code cleanup and
refactoring.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8229
2019-01-13 10:09:46 -08:00
George Wilson
c10d37dd9f zfs initialize performance enhancements
PROBLEM
========

When invoking "zpool initialize" on a pool the command will
create a thread to initialize each disk. Unfortunately, it does
this serially across many transaction groups which can result
in commands taking a long time to return to the user and may
appear hung. The same thing is true when trying to suspend/cancel
the operation.

SOLUTION
=========

This change refactors the way we invoke the initialize interface
to ensure we can start or stop the intialization in just a few
transaction groups.

When stopping or cancelling a vdev initialization perform it
in two phases.  First signal each vdev initialization thread
that it should exit, then after all threads have been signaled
wait for them to exit.

On a pool with 40 leaf vdevs this reduces the vdev initialize
stop/cancel time from ~10 minutes to under a second.  The reason
for this is spa_vdev_initialize() no longer needs to wait on
multiple full TXGs per leaf vdev being stopped.

This commit additionally adds some missing checks for the passed
"initialize_vdevs" input nvlist.  The contents of the user provided
input "initialize_vdevs" nvlist must be validated to ensure all
values are uint64s.  This is done in zfs_ioc_pool_initialize() in
order to keep all of these checks in a single location.

Updated the innvl and outnvl comments to match the formatting used
for all other new sytle ioctls.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes #8230
2019-01-07 11:03:08 -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
Serapheim Dimitropoulos
9b2266e3d8 OpenZFS 9682 - page fault in dsl_async_clone_destroy() while opening pool
Authored by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/9682
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/ade2c82828
Closes #8037
2018-10-19 12:06:21 -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
Brian Behlendorf
27f80e85c2 Improved error handling for extreme rewinds
The vdev_checkpoint_sm_object(), vdev_obsolete_sm_object(), and
vdev_obsolete_counts_are_precise() functions assume that the
only way a zap_lookup() can fail is if the requested entry is
missing.  While this is the most common cause, it's not the only
cause.  Attemping to access a damaged ZAP will result in other
errors.

The most likely scenario for accessing a damaged ZAP is during
an extreme rewind pool import.  Under these conditions the pool
is expected to contain damaged objects and the import code was
updated to handle this gracefully.  Getting an ECKSUM error from
these ZAPs after the pool in import a far less likely, therefore
the behavior for call paths was not modified.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7809
Closes #7921
2018-10-12 11:24:04 -07:00
Tom Caputi
52ce99dd61 Refcounted DSL Crypto Key Mappings
Since native ZFS encryption was merged, we have been fighting
against a series of bugs that come down to the same problem: Key
mappings (which must be present during all I/O operations) are
created and destroyed based on dataset ownership, but I/Os can
have traditionally been allowed to "leak" into the next txg after
the dataset is disowned.

In the past we have attempted to solve this problem by trying to
ensure that datasets are disowned ater all I/O is finished by
calling txg_wait_synced(), but we have repeatedly found edge cases
that need to be squashed and code paths that might incur a high
number of txg syncs. This patch attempts to resolve this issue
differently, by adding a reference to the key mapping for each txg
it is dirtied in. By doing so, we can remove many of the
unnecessary calls to txg_wait_synced() we have added in the past
and ensure we don't need to deal with this problem in the future.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7949
2018-10-03 09:47:11 -07:00
Jerry Jelinek
f65fbee1e7 OpenZFS 9700 - ZFS resilvered mirror does not balance reads
Authored by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Matthew Ahrens <mahrens@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9700
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/82f63c3c
Closes #7973
2018-10-02 16:18:24 -07:00
Tim Schumacher
424fd7c3e0 Prefix all refcount functions with zfs_
Recent changes in the Linux kernel made it necessary to prefix
the refcount_add() function with zfs_ due to a name collision.

To bring the other functions in line with that and to avoid future
collisions, prefix the other refcount functions as well.

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes #7963
2018-10-01 10:42:05 -07:00
Roman Strashkin
733b5722b4 zpool split can create a corrupted pool
Added vdev_resilver_needed() check to verify VDEVs are fully
synced, so that after split the new pool will not be corrupted.

Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Closes #7865
Closes #7881
2018-09-12 18:14:42 -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
Serapheim Dimitropoulos
a448a2557e Introduce read/write kstats per dataset
The following patch introduces a few statistics on reads and writes
grouped by dataset. These statistics are implemented as kstats
(backed by aggregate sums for performance) and can be retrieved by
using the dataset objset ID number. The motivation for this change is
to provide some preliminary analytics on dataset usage/performance.

Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #7705
2018-08-20 09:52:37 -07:00
Tom Caputi
1fff937a4c Check encrypted dataset + embedded recv earlier
This patch fixes a bug where attempting to receive a send stream
with embedded data into an encrypted dataset would not cleanup
that dataset when the error was reached. The check was moved into
dmu_recv_begin_check(), preventing this issue.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #7650
2018-08-15 09:49:19 -07:00
Paul Dagnelie
492f64e941 OpenZFS 9112 - Improve allocation performance on high-end systems
Overview
========

We parallelize the allocation process by creating the concept of
"allocators". There are a certain number of allocators per metaslab
group, defined by the value of a tunable at pool open time.  Each
allocator for a given metaslab group has up to 2 active metaslabs; one
"primary", and one "secondary". The primary and secondary weight mean
the same thing they did in in the pre-allocator world; primary metaslabs
are used for most allocations, secondary metaslabs are used for ditto
blocks being allocated in the same metaslab group.  There is also the
CLAIM weight, which has been separated out from the other weights, but
that is less important to understanding the patch.  The active metaslabs
for each allocator are moved from their normal place in the metaslab
tree for the group to the back of the tree. This way, they will not be
selected for use by other allocators searching for new metaslabs unless
all the passive metaslabs are unsuitable for allocations.  If that does
happen, the allocators will "steal" from each other to ensure that IOs
don't fail until there is truly no space left to perform allocations.

In addition, the alloc queue for each metaslab group has been broken
into a separate queue for each allocator. We don't want to dramatically
increase the number of inflight IOs on low-end systems, because it can
significantly increase txg times. On the other hand, we want to ensure
that there are enough IOs for each allocator to allow for good
coalescing before sending the IOs to the disk.  As a result, we take a
compromise path; each allocator's alloc queue max depth starts at a
certain value for every txg. Every time an IO completes, we increase the
max depth. This should hopefully provide a good balance between the two
failure modes, while not dramatically increasing complexity.

We also parallelize the spa_alloc_tree and spa_alloc_lock, which cause
very similar contention when selecting IOs to allocate. This
parallelization uses the same allocator scheme as metaslab selection.

Performance Results
===================

Performance improvements from this change can vary significantly based
on the number of CPUs in the system, whether or not the system has a
NUMA architecture, the speed of the drives, the values for the various
tunables, and the workload being performed. For an fio async sequential
write workload on a 24 core NUMA system with 256 GB of RAM and 8 128 GB
SSDs, there is a roughly 25% performance improvement.

Future Work
===========

Analysis of the performance of the system with this patch applied shows
that a significant new bottleneck is the vdev disk queues, which also
need to be parallelized.  Prototyping of this change has occurred, and
there was a performance improvement, but more work needs to be done
before its stability has been verified and it is ready to be upstreamed.

Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Alexander Motin <mav@FreeBSD.org>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>

Porting Notes:
* Fix reservation test failures by increasing tolerance.

OpenZFS-issue: https://illumos.org/issues/9112
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3f3cc3c3
Closes #7682
2018-07-31 10:52:33 -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
Matthew Ahrens
af43029484 Remove suffix from zio taskq names
For zio taskq's which have multiple instances (e.g. z_rd_int_0,
z_rd_int_1, etc), each one has a unique name (the _0, _1, _2 suffix).
This makes performance analysis more difficult, because by default,
`perf` includes the thread name (which is the same as the taskq name) in
the stack trace.  This means that we get 8 different stacks, all of
which are doing the same thing, but are executed from different taskq's.

We should remove the suffix of the taskq name, so that all the
read-interrupt threads are named z_rd_int.

Note that we already support multiple taskq's with the same name.  This
happens when there are multiple pools.  In this case the taskq has a
different tq_instance, which shows up in /proc/spl/taskq-all.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #7646
2018-06-20 14:07:50 -07:00
Pavel Zakharov
8a393be353 OpenZFS 9235 - rename zpool_rewind_policy_t to zpool_load_policy_t
We want to be able to pass various settings during import/open of a
pool, which are not only related to rewind. Instead of adding a new
policy and duplicate a bunch of code, we should just rename
rewind_policy to a more generic term like load_policy.

For instance, we'd like to set spa->spa_import_flags from the nvlist,
rather from a flags parameter passed to spa_import as in some cases we
want those flags not only for the import case, but also for the open
case. One such flag could be ZFS_IMPORT_MISSING_LOG (as used in zdb)
which would allow zfs to open a pool when logs are missing.

Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://illumos.org/issues/9235
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d2b1e44
Closes #7532
2018-06-04 14:54:20 -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
Pavel Zakharov
db7d07e14b OpenZFS 9191 - dump vdev tree to zfs_dbgmsg when spa load fails due to missing log devices
Add vdev_print_tree() in spa_check_for_missing_logs() when some log
devices are missing to ease debugging

Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
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/9191
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c5c02e5
Closes #7531
2018-05-14 14:30:52 -04:00
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
Pavel Zakharov
afd2f7b711 OpenZFS 8962 - zdb should work on non-idle pools
Currently `zdb` consistently fails to examine non-idle pools as it
fails during the `spa_load()` process. The main problem seems to be
that `spa_load_verify()` fails as can be seen below:

    $ sudo zdb -d -G dcenter
    zdb: can't open 'dcenter': I/O error

    ZFS_DBGMSG(zdb):
    spa_open_common: opening dcenter
    spa_load(dcenter): LOADING
    disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
    spa_load(dcenter): using uberblock with txg=40824950
    spa_load(dcenter): UNLOADING
    spa_load(dcenter): RELOADING
    spa_load(dcenter): LOADING
    disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
    spa_load(dcenter): using uberblock with txg=40824952
    spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
    spa_load(dcenter): UNLOADING

This change makes `spa_load_verify()` a dryrun when ran from
`zdb`. This is done by creating a global flag in zfs and then setting
it in `zdb`.

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: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/8962
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/180ad792
Closes #7459
2018-05-08 21:32:57 -07:00
Pavel Zakharov
4a0ee12af8 OpenZFS 8961 - SPA load/import should tell us why it failed
Problem
=======

When we fail to open or import a storage pool, we typically don't
get any additional diagnostic information, just "no pool found" or
"can not import".

While there may be no additional user-consumable information, we should
at least make this situation easier to debug/diagnose for developers
and support.  For example, we could start by using `zfs_dbgmsg()`
to log each thing that we try when importing, and which things
failed. E.g. "tried uberblock of txg X from label Y of device Z". Also,
we could log each of the stages that we go through in `spa_load_impl()`.

Solution
========

Following the cleanup to `spa_load_impl()`, debug messages have been
added to every point of failure in that function. Additionally,
debug messages have been added to strategic places, such as
`vdev_disk_open()`.

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: Dan McDonald <danmcd@joyent.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/8961
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/418079e0
Closes #7459
2018-05-08 21:30:10 -07:00
Brian Behlendorf
c02c1becce
ZTS: Re-enable MMP tests
Commit 7fab6361 inadvertently disabled the MMP test cases by creating
and not removing an /etc/hostid file in the new zpool_split_props test
case.  When the file exists the ZTS skips the entire MMP test group
rather than modify what may be a system which is already configured.
Update the test case to remove the file.

Additionally, because the MMP tests were disabled a regression slipped
in as part of commit 9eb7b46ed0.  Fix it.

Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7514
2018-05-07 21:08:33 -07:00
Pavel Zakharov
9eb7b46ed0 OpenZFS 7638 - Refactor spa_load_impl into several functions
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/7638
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/1fd3785ff6
Closes #7437
2018-04-16 12:24:23 -07:00
Serapheim Dimitropoulos
9d5b524597 OpenZFS 9079 - race condition in starting and ending condensing thread for indirect vdevs
The timeline of the race condition is the following:

[1] Thread A is about to finish condesing the first vdev in
    spa_condense_indirect_thread(), so it calls the
    spa_condense_indirect_complete_sync() sync task which sets
    the spa_condensing_indirect field to NULL. Waiting for the
    sync task to finish, thread A sleeps until the txg is done.
    When this happens, thread A will acquire spa_async_lock and
    set spa_condense_thread to NULL.

[2] While thread A waits for the txg to finish, thread B which is
    running spa_sync() checks whether it should condense the
    second vdev in vdev_indirect_should_condense() by checking the
    spa_condensing_indirect field which was set to NULL by
    spa_condense_indirect_thread() from thread A. So it goes on
    and tries to spawn a new condensing thread in
    spa_condense_indirect_start_sync() and the aforementioned
    assertions fails because thread A has not set spa_condense_thread
    to NULL (which is basically the last thing it does before returning).

The main issue here is that we rely on both spa_condensing_indirect
and spa_condense_thread to signify whether a condensing thread is
running. Ideally we would only use one throughout the codebase. In
addition, for managing spa_condense_thread we currently use
spa_async_lock which basically tights condensing to scrubing when
it comes to pausing and resuming those actions during spa export.

This commit introduces the ZTHR infrastructure, which is basically
threads created during spa_load()/spa_create() and exist until we
export or destroy the pool. ZTHRs sleep the majority of the time,
until they are notified to wake up and do some predefined type of work.

In the context of the current bug, a zthr to does the condensing of
indirect mappings replacing the older code that used bare kthreads.
When a pool is created, the condensing zthr is spawned but sleeps
right away, until it is awaken by a signal from spa_sync(). If an
existing pool is loaded, the condensing zthr looks if there is
anything to condense before going to sleep, in case we were condensing
mappings in the pool before it got exported.

The benefits of this solution are the following:
- The current bug is fixed
- spa_condensing_indirect is the sole indicator of whether we are
  currently condensing or not
- condensing is more decoupled from the spa_async_thread related
  functionality.

As a final note, this commit also sets up the path on upstreaming
other features that use the ZTHR code like zpool checkpoint and
fast clone deletion.

Authored by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Ported-by: Tim Chase <tim@chase2k.com>

OpenZFS-issue: https://illumos.org/issues/9079
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3dc606ee
Closes #6900
2018-04-14 12:23:53 -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