Commit Graph

201 Commits

Author SHA1 Message Date
Brian Behlendorf
b9ec4a15e5
Verify embedded blkptr's in arc_read()
The block pointer verification check in arc_read() should also
cover embedded block pointers.  While highly unlikely, accessing
a damaged block pointer can result in panic.  To further harden
the code extend the existing check to include embedded block
pointers and add a comment explaining the rational for this
sanity check.  Lastly, correct a flaw in zfs_blkptr_verify()
so the error count is checked even when checking a untrusted
config to verify the non-pool-specific portions of a block
pointer.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #12535
2021-09-09 19:02:07 -06:00
Paul Dagnelie
c634320e51
Compressed receive with different ashift can result in incorrect PSIZE on disk
We round up the psize to the nearest multiple of the asize or to the
lsize, whichever is smaller. Once that's done, we allocate a new
buffer of the appropriate size, zero the tail, and copy the data
into it. This adds a small performance cost to these kinds of writes,
but fixes the bookkeeping problems.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Matthew Ahrens <matthew.ahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #12522
Closes #8462
2021-09-08 13:52:28 -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
Alexander
23c13c7e80
A few fixes of callback typecasting (for the upcoming ClangCFI)
* zio: avoid callback typecasting
* zil: avoid zil_itxg_clean() callback typecasting
* zpl: decouple zpl_readpage() into two separate callbacks
* nvpair: explicitly declare callbacks for xdr_array()
* linux/zfs_nvops: don't use external iput() as a callback
* zcp_synctask: don't use fnvlist_free() as a callback
* zvol: don't use ops->zv_free() as a callback for taskq_dispatch()

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Closes #12260
2021-07-20 08:03:33 -06:00
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
George Amanakis
9ffcaa370a
Avoid deadlock when removing L2ARC devices under I/O
In case we have I/O and try to remove an L2ARC device a deadlock might
occur. arc_read()->zio_read()->zfs_blkptr_verify() waits for SCL_VDEV
to be dropped while holding the hash_lock. However, spa_l2cache_load()
holds SCL_ALL and waits for the hash_lock in l2arc_evict().

Fix this by moving zfs_blkptr_verify() to the top top arc_read() before
the hash_lock is taken. Verify the block pointer and return a checksum
error if damaged rather than halting the system, by using
BLK_VERIFY_LOG instead of BLK_VERIFY_HALT.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #12054
2021-06-16 18:17:42 -06:00
Mateusz Guzik
309c32c954
Combine zio caches if possible
This deduplicates 2 sets of caches which use the same allocation size.

Memory savings fluctuate a lot, one sample result is FreeBSD running
"make buildworld" saving ~180MB RAM in reduced page count associated
with zio caches.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11877
2021-04-17 12:36:04 -07:00
Paul Zuchowski
f2286383d0
Fix crash in zio_done error reporting
Fix NULL pointer dereference when reporting
checksum error for gang block in zio_done.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes #11872
Closes #11896
2021-04-16 11:00:53 -07:00
Matthew Ahrens
2b56a63457
Use a helper function to clarify gang block size
For gang blocks, `DVA_GET_ASIZE()` is the total space allocated for the
gang DVA including its children BP's.  The space allocated at each DVA's
vdev/offset is `vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE)`.

This commit makes this relationship more clear by using a helper
function, `vdev_gang_header_asize()`, for the space allocated at the
gang block's vdev/offset.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11744
2021-03-26 11:19:35 -07:00
Matthew Ahrens
330c6c0523
Clean up RAIDZ/DRAID ereport code
The RAIDZ and DRAID code is responsible for reporting checksum errors on
their child vdevs.  Checksum errors represent events where a disk
returned data or parity that should have been correct, but was not.  In
other words, these are instances of silent data corruption.  The
checksum errors show up in the vdev stats (and thus `zpool status`'s
CKSUM column), and in the event log (`zpool events`).

Note, this is in contrast with the more common "noisy" errors where a
disk goes offline, in which case ZFS knows that the disk is bad and
doesn't try to read it, or the device returns an error on the requested
read or write operation.

RAIDZ/DRAID generate checksum errors via three code paths:

1. When RAIDZ/DRAID reconstructs a damaged block, checksum errors are
reported on any children whose data was not used during the
reconstruction.  This is handled in `raidz_reconstruct()`.  This is the
most common type of RAIDZ/DRAID checksum error.

2. When RAIDZ/DRAID is not able to reconstruct a damaged block, that
means that the data has been lost.  The zio fails and an error is
returned to the consumer (e.g. the read(2) system call).  This would
happen if, for example, three different disks in a RAIDZ2 group are
silently damaged.  Since the damage is silent, it isn't possible to know
which three disks are damaged, so a checksum error is reported against
every child that returned data or parity for this read.  (For DRAID,
typically only one "group" of children is involved in each io.)  This
case is handled in `vdev_raidz_cksum_finish()`. This is the next most
common type of RAIDZ/DRAID checksum error.

3. If RAIDZ/DRAID is not able to reconstruct a damaged block (like in
case 2), but there happens to be additional copies of this block due to
"ditto blocks" (i.e. multiple DVA's in this blkptr_t), and one of those
copies is good, then RAIDZ/DRAID compares each sector of the data or
parity that it retrieved with the good data from the other DVA, and if
they differ then it reports a checksum error on this child.  This
differs from case 2 in that the checksum error is reported on only the
subset of children that actually have bad data or parity.  This case
happens very rarely, since normally only metadata has ditto blocks.  If
the silent damage is extensive, there will be many instances of case 2,
and the pool will likely be unrecoverable.

The code for handling case 3 is considerably more complicated than the
other cases, for two reasons:

1. It needs to run after the main raidz read logic has completed.  The
data RAIDZ read needs to be preserved until after the alternate DVA has
been read, which necessitates refcounts and callbacks managed by the
non-raidz-specific zio layer.

2. It's nontrivial to map the sections of data read by RAIDZ to the
correct data.  For example, the correct data does not include the parity
information, so the parity must be recalculated based on the correct
data, and then compared to the parity that was read from the RAIDZ
children.

Due to the complexity of case 3, the rareness of hitting it, and the
minimal benefit it provides above case 2, this commit removes the code
for case 3.  These types of errors will now be handled the same as case
2, i.e. the checksum error will be reported against all children that
returned data or parity.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11735
2021-03-19 16:22:10 -07:00
Don Brady
03e02e5b56
Checksum errors may not be counted
Fix regression seen in issue #11545 where checksum errors 
where not being counted or showing up in a zpool event.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #11609
2021-02-19 22:33:15 -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
Matthew Ahrens
e2af2acce3
allow callers to allocate and provide the abd_t struct
The `abd_get_offset_*()` routines create an abd_t that references
another abd_t, and doesn't allocate any pages/buffers of its own.  In
some workloads, these routines may be called frequently, to create many
abd_t's representing small pieces of a single large abd_t.  In
particular, the upcoming RAIDZ Expansion project makes heavy use of
these routines.

This commit adds the ability for the caller to allocate and provide the
abd_t struct to a variant of `abd_get_offset_*()`.  This eliminates the
cost of allocating the abd_t and performing the accounting associated
with it (`abdstat_struct_size`).  The RAIDZ/DRAID code uses this for
the `rc_abd`, which references the zio's abd.  The upcoming RAIDZ
Expansion project will leverage this infrastructure to increase
performance of reads post-expansion by around 50%.

Additionally, some of the interfaces around creating and destroying
abd_t's are cleaned up.  Most significantly, the distinction between
`abd_put()` and `abd_free()` is eliminated; all types of abd_t's are
now disposed of with `abd_free()`.

Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #8853 
Closes #11439
2021-01-20 11:24:37 -08:00
Matthew Ahrens
be5c6d9653
Only examine best metaslabs on each vdev
On a system with very high fragmentation, we may need to do lots of gang
allocations (e.g. most indirect block allocations (~50KB) may need to
gang). Before failing a "normal" allocation and resorting to ganging, we
try every metaslab.  This has the impact of loading every metaslab (not
a huge deal since we now typically keep all metaslabs loaded), and also
iterating over every metaslab for every failing allocation. If there are
many metaslabs (more than the typical ~200, e.g. due to vdev expansion
or very large vdevs), the CPU cost of this iteration can be very
impactful.  This iteration is done with the mg_lock held, creating long
hold times and high lock contention for concurrent allocations,
ultimately causing long txg sync times and poor application performance.

To address this, this commit changes the behavior of "normal" (not
try_hard, not ZIL) allocations.  These will now only examine the 100
best metaslabs (as determined by their ms_weight).  If none of these
have a large enough free segment, then the allocation will fail and
we'll fall back on ganging.

To accomplish this, we will now (normally) gang before doing a
`try_hard` allocation.  Non-try_hard allocations will only examine the
100 best metaslabs of each vdev.  In summary, we will first try normal
allocation.  If that fails then we will do a gang allocation.  If that
fails then we will do a "try hard" gang allocation.  If that fails then
we will have a multi-layer gang block.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11327
2020-12-16 14:40:05 -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
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
Mateusz Guzik
18ca574f0a
G/C data_alloc_arena
It is a leftover from illumos always set to NULL and introducing a
spurious difference between zio_buf and zio_data_buf.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11188
2020-11-11 17:11:32 -08:00
Mateusz Guzik
09eb36ce3d
Introduce CPU_SEQID_UNSTABLE
Current CPU_SEQID users don't care about possibly changing CPU ID, but
enclose it within kpreempt disable/enable in order to fend off warnings
from Linux's CONFIG_DEBUG_PREEMPT.

There is no need to do it. The expected way to get CPU ID while allowing
for migration is to use raw_smp_processor_id.

In order to make this future-proof this patch keeps CPU_SEQID as is and
introduces CPU_SEQID_UNSTABLE instead, to make it clear that consumers
explicitly want this behavior.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Closes #11142
2020-11-02 11:51:12 -08:00
Ryan Moeller
76d04993a6
Update references to nonexistent man pages in code
Refer to the correct section or alternative for FreeBSD and Linux.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11132
2020-10-30 08:55:59 -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
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
Michael Niewöhner
10b3c7f5e4 Add zstd support to zfs
This PR adds two new compression types, based on ZStandard:

- zstd: A basic ZStandard compression algorithm Available compression.
  Levels for zstd are zstd-1 through zstd-19, where the compression
  increases with every level, but speed decreases.

- zstd-fast: A faster version of the ZStandard compression algorithm
  zstd-fast is basically a "negative" level of zstd. The compression
  decreases with every level, but speed increases.

  Available compression levels for zstd-fast:
   - zstd-fast-1 through zstd-fast-10
   - zstd-fast-20 through zstd-fast-100 (in increments of 10)
   - zstd-fast-500 and zstd-fast-1000

For more information check the man page.

Implementation details:

Rather than treat each level of zstd as a different algorithm (as was
done historically with gzip), the block pointer `enum zio_compress`
value is simply zstd for all levels, including zstd-fast, since they all
use the same decompression function.

The compress= property (a 64bit unsigned integer) uses the lower 7 bits
to store the compression algorithm (matching the number of bits used in
a block pointer, as the 8th bit was borrowed for embedded block
pointers).  The upper bits are used to store the compression level.

It is necessary to be able to determine what compression level was used
when later reading a block back, so the concept used in LZ4, where the
first 32bits of the on-disk value are the size of the compressed data
(since the allocation is rounded up to the nearest ashift), was
extended, and we store the version of ZSTD and the level as well as the
compressed size. This value is returned when decompressing a block, so
that if the block needs to be recompressed (L2ARC, nop-write, etc), that
the same parameters will be used to result in the matching checksum.

All of the internal ZFS code ( `arc_buf_hdr_t`, `objset_t`,
`zio_prop_t`, etc.) uses the separated _compress and _complevel
variables.  Only the properties ZAP contains the combined/bit-shifted
value. The combined value is split when the compression_changed_cb()
callback is called, and sets both objset members (os_compress and
os_complevel).

The userspace tools all use the combined/bit-shifted value.

Additional notes:

zdb can now also decode the ZSTD compression header (flag -Z) and
inspect the size, version and compression level saved in that header.
For each record, if it is ZSTD compressed, the parameters of the decoded
compression header get printed.

ZSTD is included with all current tests and new tests are added
as-needed.

Per-dataset feature flags now get activated when the property is set.
If a compression algorithm requires a feature flag, zfs activates the
feature when the property is set, rather than waiting for the first
block to be born.  This is currently only used by zstd but can be
extended as needed.

Portions-Sponsored-By: The FreeBSD Foundation
Co-authored-by: Allan Jude <allanjude@freebsd.org>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Co-authored-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Co-authored-by: Michael Niewöhner <foss@mniewoehner.de>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Allan Jude <allanjude@freebsd.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Closes #6247
Closes #9024
Closes #10277
Closes #10278
2020-08-20 10:30:06 -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
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
Matthew Ahrens
3f38797338
Compile cityhash code into libzfs
Make the cityhash code compile into libzfs, in preparation for the new
"zstream" command.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10152
2020-03-27 09:11:22 -07:00
Brian Behlendorf
f49db9b504
zio: dprintf_bp() if errors > 0 in zfs_blkptr_verify()
Also dprintf_bp() in case BLK_VERIFY_HALT of zfs_blkptr_verify_log()
since dprintf_bp() in zfs_blkptr_verify() will never be executed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Justin Keogh <commits@v6y.net>
Closes #10086
2020-03-04 15:08:41 -08:00
Matthew Ahrens
b3212d2fa6
Improve performance of zio_taskq_member
__zio_execute() calls zio_taskq_member() to determine if we are running
in a zio interrupt taskq, in which case we may need to switch to
processing this zio in a zio issue taskq.  The call to
zio_taskq_member() can become a performance bottleneck when we are
processing a high rate of zio's.

zio_taskq_member() calls taskq_member() on each of the zio interrupt
taskqs, of which there are 21.  This is slow because each call to
taskq_member() does tsd_get(taskq_tsd), which on Linux is relatively
slow.

This commit improves the performance of zio_taskq_member() by having it
cache the value of tsd_get(taskq_tsd), reducing the number of those
calls to 1/21th of the current behavior.

In a test case running `zfs send -c >/dev/null` of a filesystem with
small blocks (average 2.5KB/block), zio_taskq_member() was using 6.7% of
one CPU, and with this change it is reduced to 1.3%.  Overall time to
perform the `zfs send` reduced by 10% (~150,000 block/sec to ~165,000
blocks/sec).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10070
2020-03-03 10:29:38 -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
Paul Zuchowski
bc67cba7c0
Fix zdb -R with 'b' flag
zdb -R :b fails due to the indirect block being compressed,
and the 'b' and 'd' flag not working in tandem when specified.
Fix the flag parsing code and create a zfs test for zdb -R
block display.  Also fix the zio flags where the dotted notation
for the vdev portion of DVA (i.e. 0.0:offset:length) fails.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Zuchowski <pzuchowski@datto.com>
Closes #9640
Closes #9729
2020-02-10 14:00:05 -08:00
Matthew Macy
d3c1e45b7a Re-consolidate zio_delay_interrupt
With recent SPL changes there is no longer any need for a per
platform version.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9860
2020-01-21 15:04:13 -08:00
Matthew Macy
3c502d3b75 Exclude data from cores unconditionally and metadata conditionally
This change allows us to align the code dump logic across platforms.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9691
2019-12-09 12:29:56 -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
Prakash Surya
e5d1c27e30 Enable use of DTRACE_PROBE* macros in "spl" module
This change modifies some of the infrastructure for enabling the use of
the DTRACE_PROBE* macros, such that we can use tehm in the "spl" module.

Currently, when the DTRACE_PROBE* macros are used, they get expanded to
create new functions, and these dynamically generated functions become
part of the "zfs" module.

Since the "spl" module does not depend on the "zfs" module, the use of
DTRACE_PROBE* in the "spl" module would result in undefined symbols
being used in the "spl" module. Specifically, DTRACE_PROBE* would turn
into a function call, and the function being called would be a symbol
only contained in the "zfs" module; which results in a linker and/or
runtime error.

Thus, this change adds the necessary logic to the "spl" module, to
mirror the tracing functionality available to the "zfs" module. After
this change, we'll have a "trace_zfs.h" header file which defines the
probes available only to the "zfs" module, and a "trace_spl.h" header
file which defines the probes available only to the "spl" module.

Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #9525
2019-11-01 13:13:43 -07:00
Matthew Macy
c324701332 Move zio_delay_interrupt to platform code
FreeBSD has its own implementation as do other platforms.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9439
2019-10-13 19:15:27 -07:00
Matthew Macy
d66620681d OpenZFS restructuring - move linux tracing code to platform directories
Move Linux specific tracing headers and source to platform directories
and update the build system.

Reviewed-by: Allan Jude <allanjude@freebsd.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #9290
2019-09-11 14:25:53 -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
Paul Dagnelie
dc04a8c757 Prevent race in blkptr_verify against device removal
When we check the vdev of the blkptr in zfs_blkptr_verify, we can run 
into a race condition where that vdev is temporarily unavailable. This 
happens when a device removal operation and the old vdev_t has been 
removed from the array, but the new indirect vdev has not yet been 
inserted.

We hold the spa_config_lock while doing our sensitive verification. 
To ensure that we don't deadlock, we only grab the lock if we don't 
have config_writer held. In addition, I had to const the tags of the 
refcounts and the spa_config_lock arguments.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #9112
2019-08-13 21:24:43 -06:00
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
George Wilson
681a85cb01 nopwrites on dmu_sync-ed blocks can result in a panic
After device removal, performing nopwrites on a dmu_sync-ed block
will result in a panic. This panic can show up in two ways:
1. an attempt to issue an IOCTL in vdev_indirect_io_start()
2. a failed comparison of zio->io_bp and zio->io_bp_orig in
   zio_done()
To resolve both of these panics, nopwrites of blocks on indirect
vdevs should be ignored and new allocations should be performed on
concrete vdevs.

Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
Closes #8957
2019-06-28 12:40:23 -07:00
loli10K
746d4a451e Fix bp_embedded_type enum definition
With the addition of BP_EMBEDDED_TYPE_REDACTED in 30af21b0 a couple of
codepaths make wrong assumptions and could potentially result in errors.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes #8951
2019-06-24 18:02:17 -07:00
Matthew Ahrens
accd6d9dc4 dedup=verify doesn't clear the blkptr's dedup flag
The logic to handle strong checksum collisions where the data doesn't
match is incorrect. It is not clearing the dedup bit of the blkptr,
which can cause a panic later in zio_ddt_free() due to the dedup table
not matching what is in the blkptr.

Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-48097
Closes #8936
2019-06-20 18:30:40 -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
Matthew Ahrens
be89734a29 compress metadata in later sync passes
Starting in sync pass 5 (zfs_sync_pass_dont_compress), we disable
compression (including of metadata).  Ostensibly this helps the sync
passes to converge (i.e. for a sync pass to not need to allocate
anything because it is 100% overwrites).

However, in practice it increases the average number of sync passes,
because when we turn compression off, a lot of block's size will change
and thus we have to re-allocate (not overwrite) them.  It also increases
the number of 128KB allocations (e.g. for indirect blocks and spacemaps)
because these will not be compressed.  The 128K allocations are
especially detrimental to performance on highly fragmented systems,
which may have very few free segments of this size, and may need to load
new metaslabs to satisfy 128K allocations.

We should increase zfs_sync_pass_dont_compress.  In practice on a highly
fragmented system we see a few 5-pass txg's, a tiny number of 6-pass
txg's, and no txg's with more than 6 passes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-63431
Closes #8892
2019-06-13 13:10:18 -07:00
Matthew Ahrens
5662fd5794 single-chunk scatter ABDs can be treated as linear
Scatter ABD's are allocated from a number of pages.  In contrast to
linear ABD's, these pages are disjoint in the kernel's virtual address
space, so they can't be accessed as a contiguous buffer.  Therefore
routines that need a linear buffer (e.g. abd_borrow_buf() and friends)
must allocate a separate linear buffer (with zio_buf_alloc()), and copy
the contents of the pages to/from the linear buffer.  This can have a
measurable performance overhead on some workloads.

https://github.com/zfsonlinux/zfs/commit/87c25d567fb7969b44c7d8af63990e
("abd_alloc should use scatter for >1K allocations") increased the use
of scatter ABD's, specifically switching 1.5K through 4K (inclusive)
buffers from linear to scatter.  For workloads that access blocks whose
compressed sizes are in this range, that commit introduced an additional
copy into the read code path.  For example, the
sequential_reads_arc_cached tests in the test suite were reduced by
around 5% (this is doing reads of 8K-logical blocks, compressed to 3K,
which are cached in the ARC).

This commit treats single-chunk scattered buffers as linear buffers,
because they are contiguous in the kernel's virtual address space.

All single-page (4K) ABD's can be represented this way.  Some multi-page
ABD's can also be represented this way, if we were able to allocate a
single "chunk" (higher-order "page" which represents a power-of-2 series
of physically-contiguous pages).  This is often the case for 2-page (8K)
ABD's.

Representing a single-entry scatter ABD as a linear ABD has the
performance advantage of avoiding the copy (and allocation) in
abd_borrow_buf_copy / abd_return_buf_copy.  A performance increase of
around 5% has been observed for ARC-cached reads (of small blocks which
can take advantage of this), fixing the regression introduced by
87c25d567.

Note that this optimization is only possible because all physical memory
is always mapped into the kernel's address space.  This is not the case
for HIGHMEM pages, so the optimization can not be made on 32-bit
systems.

Reviewed-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #8580
2019-06-11 09:02:31 -07:00
Sara Hartse
a887d653b3 Restrict kstats and print real pointers
There are several places where we use zfs_dbgmsg and %p to
print pointers. In the Linux kernel, these values obfuscated
to prevent information leaks which means the pointers aren't
very useful for debugging crash dumps. We decided to restrict
the permissions of dbgmsg (and some other kstats while we were
at it) and print pointers with %px in zfs_dbgmsg as well as
spl_dumpstack

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Signed-off-by: sara hartse <sara.hartse@delphix.com>
Closes #8467 
Closes #8476
2019-04-04 18:57:06 -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
Tony Hutter
2bbec1c910 Make zpool status counters match error events count
The number of IO and checksum events should match the number of errors
seen in zpool status.  Previously there was a mismatch between the
two counts because zpool status would only count unrecovered errors,
while zpool events would get an event for *all* errors (recovered or
not).  This lead to situations where disks could be faulted for
"too many errors", while at the same time showing zero errors in zpool
status.

This fixes the zpool status error counters to increment at the same
times we post the error events.

Reviewed-by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #4851 
Closes #7817
2019-03-14 18:21:53 -07:00
Sara Hartse
f545b6ae00 Delay injection can cause indefinitely hung zios
If we hit the (NSEC_TO_TICK(diff) == 0) condition in
zio_delay_interrupt, zio_interrupt is never called and the
zio does not progress.

Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: sara hartse <sara.hartse@delphix.com>
Closes #8404
2019-02-15 14:44:56 -08:00
Tim Chase
638dd5f44e zio_deadman_impl() fix and enhancement
Add the zio_deadman_log_all tunable to print all zios in
zio_deadman_impl().  Also, in all cases, display the depth of the
zio relative to the original parent zio.  This is meant to be used by
developers to gain diagnostic information for hangs which don't involve
fully set-up zio trees or are otherwise stuck or hung in an early stage.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #8362
2019-02-15 12:44:24 -08:00