Commit Graph

736 Commits

Author SHA1 Message Date
наб c52612ba03 zed.8: don't pretend an unprivileged user could change the script owner
And add a note on /why/ ZEDLETs need to be owned by root

Quoth chown(2), Linux man-pages project:
  Only a privileged process (Linux: one with the CAP_CHOWN capability)
  may change the owner of a file.

Quoth chown(2), FreeBSD:
     [EPERM]  The operation would change the ownership,
              but the effective user ID is not the super-user.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11834
2021-04-07 14:51:06 -07:00
наб ed519ad495 zed: purge all mentions of a configuration file
There simply isn't a need for one, since the flags the daemon takes
are all short (mostly just toggles) and administrative in nature,
and are therefore better served by the age-old tradition of sourcing an
environment file and preparing the cmdline in the init-specific handler
itself, if needed at all

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11834
2021-04-07 14:50:52 -07:00
наб 57a1214e3a
zpool-features.5: remove "booting not possible with this feature"s
The exact limitations on what features are supported when booting
vary considerably depending on the environment.  In order to minimize
confusion avoid categorical statements which assume GRUB2 is being 
used.  The supported GRUB2 features are covered earlier in this man 
page for easy reference.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11842
2021-04-06 12:39:54 -07:00
George Melikov d35708b187
man: fix wrong .Xr macros usages
In addition, html doc will have working hyperlinks.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes #11845
2021-04-06 12:27:40 -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
наб 73218f41b4 zed: allow limiting concurrent jobs
200ms time-out is relatively long, but if we already hit the cap,
then we'll likely be able to spawn multiple new jobs when we wake up

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11807
2021-04-02 16:30:53 -07:00
наб ca2ce9c50b zed: use separate reaper thread and collect ZEDLETs asynchronously
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11807
2021-04-02 16:30:08 -07:00
Ryan Moeller 032a213e2e Don't scale zfs_zevent_len_max by CPU count
The lower bound for this scaling to too low and the upper bound is too
high.  Use a fixed default length of 512 instead, which is a reasonable
value on any system.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11822
2021-04-01 08:45:04 -07:00
наб 0c2eb3f540
fsck.zfs: implement 4/8 exit codes as suggested in manpage
Update the fsck.zfs helper to bubble up some already-known-about 
errors if they are detected in the pool.

health=degraded => 4/"Filesystem errors left uncorrected"
health=faulted && dataset in /etc/fstab => 8/"Operational error"
pool not found => 8/"Operational error"
everything else => 0

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11806
2021-03-31 10:49:56 -07:00
наб 38280c3526
zed: reap child after killing on time-out
When a child process is killed waitpid() must be called on the
pid the reap the zombie process.

Update BUGS section to reflect reality by replacing "zedlets
aren't time limited with "zedlets can be interrupted".

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11769 
Closes #11798
2021-03-26 14:21:00 -07:00
Ryan Moeller 0ab84bff55
Fix typo in zgenhostid.8
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11770
2021-03-19 22:39:42 -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
gldisater 07dff5cffe
Hold and release permissions exist
The man page was missing these two permissions.
Add the missing permissions to the man page. 

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jeremy Faulkner <gldisater@gldis.ca>
Closes #11727
2021-03-16 15:01:21 -07:00
Don Brady dd0b5c8559
Reference_tracking_enable should be a module param
To make use of zfs_refcount_held tunable it should be a module 
parameter in open-zfs.  Also, since the macros will auto-generate OS 
specific tunables, removed the existing zfs_refcount_held reference 
in module/os/freebsd/zfs/sysctl_os.c.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes #11753
2021-03-16 14:56:17 -07:00
Martin Matuška b8fa03efbc
Fix whitespace introduced in ecc277cff
The manual page change in ecc277c has introduced whitespace on
line ends.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes #11722
2021-03-11 19:42:04 -08:00
manfromafar ecc277cff7
Clarify compressed zfs send/recv behavior
Docs for send and receive do not explain behavior when sending a 
compressed stream then receiving on a host that overrides compression 
with -o compress=value.

The data from the send stream is written as it was from the send is 
the compressed form but the compression algorithm set on the receiver 
is the overridden version which causes some confusion as to what 
algorithm was actually used.

Updated man docs to clarify behavior

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed By: Allan Jude <allanjude@freebsd.org>
Signed-off-by: manfromafar <manfromafar@outlook.com>
Closes #11690
2021-03-07 09:39:16 -08:00
Brian Behlendorf 1dfc82a14e
Linux: increase max nvlist_src size
On Linux increase the maximum allowed size of the src nvlist which
can be passed to the /dev/zfs ioctl.  Originally, this was set
to a maximum of KMALLOC_MAX_SIZE (4M) because it was kmalloc'd.
Since that time it's been converted to a vmalloc so that's no
longer a hard limit, and it's desirable for `zfs send/recv` to
allow larger nvlists so more snapshots can be sent at once.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6572
Closes #11638
2021-02-24 09:57:18 -08:00
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
Brian Behlendorf d66f017c17
zfs-list.8: clarify listing snapshots
Clarify how to include snapshots in the `zpool list` output by
referencing the full name of the `listsnapshots` pool property,
and the `zpool list -t snapshot` option.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11562
Closes #11565
2021-02-04 09:56:28 -08:00
Allan Jude 393e69241e
Add zdb -r <dataset> <object-id | file> <output>
While you can use zdb -R poolname vdev:offset:[<lsize>/]<psize>[:flags] 
to extract individual DVAs from a vdev, it would be handy for be able 
copy an entire file out of the pool.

Given a file or object number, add support to copy the contents to a 
file. Useful for debugging and recovery.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes #11027
2021-01-27 21:36:01 -08:00
Alan Somers dfb44c500e
Fix a man page link in zfs-program.8
zfs-program.8 has an orphan link, fix it.

https://svnweb.freebsd.org/base?view=revision&revision=360080

Obtained from: FreeBSD
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes #11529
2021-01-26 16:17:11 -08:00
наб 8887760aef
zfsprops.8: fix mispluralisation in "Default values is"
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11509
2021-01-24 15:57:51 -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 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
Ryan Moeller 4b6e2a5a33
Add -u option to 'zfs create'
Add -u option to 'zfs create' that prevents file system from being
automatically mounted. This is similar to the 'zfs receive -u'.

Authored by: pjd <pjd@FreeBSD.org>
FreeBSD-commit: freebsd/freebsd@35c58230e2

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Ported-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11254
2020-12-04 14:01:42 -08:00
melak 766e06695f
Fix trivial typo in zfs-diff.8
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tamas TEVESZ <ice@extreme.hu>
Closes #11268 
Closes #11272
2020-12-03 10:18:26 -08:00
Alexander Motin 6f5aac3ca0
Reduce latency effects of non-interactive I/O
Investigating influence of scrub (especially sequential) on random read
latency I've noticed that on some HDDs single 4KB read may take up to 4
seconds!  Deeper investigation shown that many HDDs heavily prioritize
sequential reads even when those are submitted with queue depth of 1.

This patch addresses the latency from two sides:
 - by using _min_active queue depths for non-interactive requests while
   the interactive request(s) are active and few requests after;
 - by throttling it further if no interactive requests has completed
   while configured amount of non-interactive did.

While there, I've also modified vdev_queue_class_to_issue() to give
more chances to schedule at least _min_active requests to the lowest
priorities.  It should reduce starvation if several non-interactive
processes are running same time with some interactive and I think should
make possible setting of zfs_vdev_max_active to as low as 1.

I've benchmarked this change with 4KB random reads from ZVOL with 16KB
block size on newly written non-fragmented pool.  On fragmented pool I
also saw improvements, but not so dramatic.  Below are log2 histograms
of the random read latency in milliseconds for different devices:

4 2x mirror vdevs of SATA HDD WDC WD20EFRX-68EUZN0 before:
0, 0, 2,  1,  12,  21,  19,  18, 10, 15, 17, 21
after:
0, 0, 0, 24, 101, 195, 419, 250, 47,  4,  0,  0
, that means maximum latency reduction from 2s to 500ms.

4 2x mirror vdevs of SATA HDD WDC WD80EFZX-68UW8N0 before:
0, 0,  2,  31,  38,  28,  18,  12, 17, 20, 24, 10, 3
after:
0, 0, 55, 247, 455, 470, 412, 181, 36,  0,  0,  0, 0
, i.e. from 4s to 250ms.

1 SAS HDD SEAGATE ST14000NM0048 before:
0,  0,  29,   70, 107,   45,  27, 1, 0, 0, 1, 4, 19
after:
1, 29, 681, 1261, 676, 1633,  67, 1, 0, 0, 0, 0,  0
, i.e. from 4s to 125ms.

1 SAS SSD SEAGATE XS3840TE70014 before (microseconds):
0, 0, 0, 0, 0, 0, 0, 0,  70, 18343, 82548, 618
after:
0, 0, 0, 0, 0, 0, 0, 0, 283, 92351, 34844,  90

I've also measured scrub time during the test and on idle pools.  On
idle fragmented pool I've measured scrub getting few percent faster
due to use of QD3 instead of QD2 before.  On idle non-fragmented pool
I've measured no difference.  On busy non-fragmented pool I've measured
scrub time increase about 1.5-1.7x, while IOPS increase reached 5-9x.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #11166
2020-11-24 09:26:42 -08:00
наб fd654e412e zpool(8): fix pool-wi[sd]e typo
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11202
2020-11-16 09:26:16 -08:00
Érico Rolim 9c4b6dbb31 zgenhostid: accept hostid arguments equal to zero.
A common usage pattern for zgenhostid, including in the ZFS dracut
module, is running it as:

  zgenhostid $(hostid)

However, zgenhostid only accepted hostid arguments greater than 0, which
meant that, when the output of hostid(1) was "00000000", zgenhostid
would error out, even though 0 is a possible return value for the
gethostid(3) function used by hostid(1):

- On current musl libc, gethostid(3) is a stub that always returns 0.
- On glibc, gethostid(3) will return 0 if /etc/hostid exists but is
  smaller than 4 bytes.

In these cases, it makes more sense for zgenhostid to treat a value of 0
as other parts of the zfs codebase do, meaning that a hostid value
couldn't be determined; therefore, it should attempt to generate a
random value to write into /etc/hostid.

The manpage and usage output have been updated to reflect this.

Whitespace has also been fixed in the usage output.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Georgy Yakovlev <gyakovlev@gentoo.org>
Reviewed-by: Andrew J. Hesford <ajh@sideband.org>
Signed-off-by: Érico Rolim <erico.erc@gmail.com>
Closes #11174
Closes #11189
2020-11-14 17:20:54 -08:00
Matthew Ahrens d66aab7c08
Assertion failure when logging large output of channel program
The output of ZFS channel programs is logged on-disk in the zpool
history, and printed by `zpool history -i`.  Channel programs can use
10MB of memory by default, and up to 100MB by using the `zfs program -m`
flag.  Therefore their output can be up to some fraction of 100MB.

In addition to being somewhat wasteful of the limited space reserved for
the pool history (which for large pools is 1GB), in extreme cases this
can result in a failure of `ASSERT(length <= DMU_MAX_ACCESS);` in
`dmu_buf_hold_array_by_dnode()`.

This commit limits the output size that will be logged to 1MB.  Larger
outputs will not be logged, instead a entry will be logged indicating
the size of the omitted output.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #11194
2020-11-14 10:17:16 -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
наб b60ae3a5dc
zpoolprops.8: clarify vdev expansion rules
Remove reference to EFI(?), explain that the new space
is beyond the GPT for whole-disk vdevs, and add section noting how it
behaves with partition vdevs in terms of how the user is most likely to
encounter it ‒ the previous phrasing was confusing
and seemed to indicate that "zpool online -e" will be able to claim

  GPT[whatever, ZFS, free space, whatever]

into

  GPT[whatever, ZFS, whatever]
but that's not the case, as it'll only be able to do so after manually
resizing the ZFS partition to include the free space beforehand, i.e.:
  GPT[whatever, ZFS, free space, whatever]
  GPT[whatever, [ZFS + free space], potentially left-overs, whatever]
  # zpool online -e
  GPT[whatever, ZFS, whatever]

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11158
2020-11-10 12:48:26 -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
xtouqh 1e36af8c7b
Properly format NAME subsection of zfs/zpool subcommands
Use proper names (i.e. zfs-allow and zpool-add) in NAME subsections
of zfs/zpool subcommands instead of current "pretty-printed" ones as
makewhatis utilities (or some implementations of it, namely the one
from mandoc suite used in FreeBSD) look not only at the document title
but also in NAME subsection, adding zfs(8)/zpool(8) to search results
which is not correct. (Common sense and other utilities splitting
subcommands in multiple man pages, e.g. git, do the same.)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: xtouqh <xtouqh@hotmail.com>
Closes #11086
2020-10-22 11:28:10 -07:00
Ryan Moeller 2aaab887bb
arcstat: Add -a and -p options from FreeNAS
Added -a option to automatically print all valid statistics.
Added -p option to suppress scaling of printed data.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Authored by: Nick Principe <32284693+powernap@users.noreply.github.com>
Ported-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11090
2020-10-21 14:09:14 -07:00
Ryan Moeller 485b50bb9e
Cross-platform acltype
The acltype property is currently hidden on FreeBSD and does not
reflect the NFSv4 style ZFS ACLs used on the platform.  This makes it
difficult to observe that a pool imported from FreeBSD on Linux has a
different type of ACL that is being ignored, and vice versa.

Add an nfsv4 acltype and expose the property on FreeBSD.

Make the default acltype nfsv4 on FreeBSD.

Setting acltype to an unhanded style is treated the same as setting
it to off.  The ACLs will not be removed, but they will be ignored.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10520
2020-10-13 21:25:48 -07:00
Ryan Moeller 7dfc56d866
Expose zfetch_max_idistance tunable
FreeBSD had this value tunable before the switch to the new OpenZFS.
The tunable name has changed, breaking legacy compat.

Restore legacy compat for this tunable, properly expose the tunable
with the new name on all platforms, and document it in
zfs-module-parameters(5).

While here, clean up the documentation for zfetch_max_distance a bit.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11038
2020-10-13 09:32:34 -07:00
Richard Elling e9527d44e6
Add zpool_influxdb command
A zpool_influxdb command is introduced to ease the collection
of zpool statistics into the InfluxDB time-series database.
Examples are given on how to integrate with the telegraf
statistics aggregator, a companion to influxdb.

Finally, a grafana dashboard template is included to show
how pool latency distributions can be visualized in a
ZFS + telegraf + influxdb  + grafana environment.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Elling <Richard.Elling@RichardElling.com>
Closes #10786
2020-10-09 09:29:21 -07:00
Ryan Moeller b7ab7ae241
Linux: Initialize zp in zfs_setattr_dir
The value of zp is used without having been initialized under some
conditions.  Initialize the pointer to NULL.

Add a regression test case using chown in acl/posix.  However, this is
not enough because the setup sets xattr=sa, which means zfs_setattr_dir
will not be called.  Create a second group of acl tests in acl/posix-sa
duplicating the acl/posix tests with symlinks, and remove xattr=sa from
the original acl/posix tests.  This provides more coverage for the
default xattr=on code.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10043
Closes #11025
2020-10-09 09:27:14 -07:00
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
grodik 53245fe337 Note that keys must be loaded for 'zpool remove'
The error returned by `zpool remove` when the encryption keys aren't
loaded isn't very helpful.  Furthermore, the man pages make no
mention that the keys need to be loaded. This change doesn't resolve
the error message but it does update the man page to mention this
requirement.

Authored-by: grodik <pat@litke.dev>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10939
Closes #10948
2020-09-28 16:11:57 -07:00
Allan Jude cf2667759f
zfs userspace: use zfs_path_to_zhandle so argument can be a path
Change zfs userspace subcommand to use zfs_path_to_zhandle() so that
the provided dataset can be a path (/usr) or a dataset (rpool/usr).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes #8915
2020-09-25 14:37:10 -07:00
George Amanakis 37b00fb039
Update documentation of l2arc_mfuonly
with regard to evicted_l2_eligibile_mru. Even if l2arc_mfuonly is
enabled, this is not reflected in evicted_l2_eligible_mru as this
information is useful for deciding whether to toggle l2arc_mfuonly
depending on the current workload.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10945
2020-09-21 09:26:24 -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
Ryan Moeller 7ead2be3d2
Rename acltype=posixacl to acltype=posix
Prefer acltype=off|posix, retaining the old names as aliases.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10918
2020-09-16 12:26:06 -07:00
Georgy Yakovlev 9cc177baa0
cmd/zgenhostid: replace with simple c implementation
It was discovered that dracut scripts and zgenhostid
always generate little-endian /etc/hostid.

This commit provides simple endianess-aware binary
and updates the scripts to use it.

New features include:
 -f flag to force overwrite.
 -o flag to write to different file (for dracut)
 accepting both 0x01234567 and 01234567 values as input

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>
Closes #10887 
Closes #10925
2020-09-16 12:25:12 -07:00
наб 5797d7cc4c
zpoolprops.8: fix raidz par[i]ty typo
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #10923
2020-09-15 15:43:42 -07:00
George Amanakis 085321621e
Add L2ARC arcstats for MFU/MRU buffers and buffer content type
Currently the ARC state (MFU/MRU) of cached L2ARC buffer and their
content type is unknown. Knowing this information may prove beneficial
in adjusting the L2ARC caching policy.

This commit adds L2ARC arcstats that display the aligned size
(in bytes) of L2ARC buffers according to their content type
(data/metadata) and according to their ARC state (MRU/MFU or
prefetch). It also expands the existing evict_l2_eligible arcstat to
differentiate between MFU and MRU buffers.

L2ARC caches buffers from the MRU and MFU lists of ARC. Upon caching a
buffer, its ARC state (MRU/MFU) is stored in the L2 header
(b_arcs_state). The l2_m{f,r}u_asize arcstats reflect the aligned size
(in bytes) of L2ARC buffers according to their ARC state (based on
b_arcs_state). We also account for the case where an L2ARC and ARC
cached MRU or MRU_ghost buffer transitions to MFU. The l2_prefetch_asize
reflects the alinged size (in bytes) of L2ARC buffers that were cached
while they had the prefetch flag set in ARC. This is dynamically updated
as the prefetch flag of L2ARC buffers changes.

When buffers are evicted from ARC, if they are determined to be L2ARC
eligible then their logical size is recorded in
evict_l2_eligible_m{r,f}u arcstats according to their ARC state upon
eviction.

Persistent L2ARC:
When committing an L2ARC buffer to a log block (L2ARC metadata) its
b_arcs_state and prefetch flag is also stored. If the buffer changes
its arcstate or prefetch flag this is reflected in the above arcstats.
However, the L2ARC metadata cannot currently be updated to reflect this
change.
Example: L2ARC caches an MRU buffer. L2ARC metadata and arcstats count
this as an MRU buffer. The buffer transitions to MFU. The arcstats are
updated to reflect this. Upon pool re-import or on/offlining the L2ARC
device the arcstats are cleared and the buffer will now be counted as an
MRU buffer, as the L2ARC metadata were not updated.

Bug fix:
- If l2arc_noprefetch is set, arc_read_done clears the L2CACHE flag of
  an ARC buffer. However, prefetches may be issued in a way that
  arc_read_done() is bypassed. Instead, move the related code in
  l2arc_write_eligible() to account for those cases too.

Also add a test and update manpages for l2arc_mfuonly module parameter,
and update the manpages and code comments for l2arc_noprefetch.
Move persist_l2arc tests to l2arc.

Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10743
2020-09-14 10:10:44 -07:00
George Amanakis feb3a7eef1
Introduce ZFS module parameter l2arc_mfuonly
In certain workloads it may be beneficial to reduce wear of L2ARC
devices by not caching MRU metadata and data into L2ARC. This commit
introduces a new tunable l2arc_mfuonly for this purpose.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10710
2020-09-08 11:44:37 -07:00
Ryan Moeller 3ec88ab205 man: Cross-reference zfs-load-key(8) for ENCRYPTION mention
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Submitted-by: Harry Schmalzbauer
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10866
2020-09-04 10:53:59 -07:00
Ryan Moeller 782b1c1249 man: Add `zfs rename -r` to zfs-rename(8) SYNOPSIS
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10866
2020-09-04 10:53:22 -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
Ryan Moeller 7b4e27232d
Add 'zfs rename -u' to rename without remounting
Allow to rename file systems without remounting if it is possible.
It is possible for file systems with 'mountpoint' property set to
'legacy' or 'none' - we don't have to change mount directory for them.
Currently such file systems are unmounted on rename and not even
mounted back.

This introduces layering violation, as we need to update
'f_mntfromname' field in statfs structure related to mountpoint (for
the dataset we are renaming and all its children).

In my opinion it is worth it, as it allow to update FreeBSD in even
cleaner way - in ZFS-only configuration root file system is ZFS file
system with 'mountpoint' property set to 'legacy'. If root dataset is
named system/rootfs, we can snapshot it (system/rootfs@upgrade), clone
it (system/oldrootfs), update FreeBSD and if it doesn't boot we can
boot back from system/oldrootfs and rename it back to system/rootfs
while it is mounted as /. Before it was not possible, because
unmounting / was not possible.

Authored by: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported by: Matt Macy <mmacy@freebsd.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10839
2020-09-01 16:14:16 -07:00
John-Mark Gurney 770269ef3a
Add the Xr's to the SEE ALSO as well
There are a ton of zfs-* and zpool-* man pages. This adds them to 
the SEE ALSO section so that people can more quickly look through 
what all the options are, now that the pages have been split.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: John-Mark Gurney <jmg@funkthat.com>
Closes #10589
2020-08-26 22:29:00 -07:00
Alexander Motin 523e1295fe
Introduce limit on size of L2ARC headers
Since L2ARC buffers are not evicted on memory pressure, too large
amount of headers on system with irrationally large L2ARC can render
it slow or even unusable.  This change limits L2ARC writes and
rebuild if unevictable L2ARC-only headers reach dangerous level.

While there, call arc_adapt() on L2ARC rebuild, so that it could
properly grow arc_c, reflecting potentially significant ARC size
increase and avoiding slow growth with hopeless eviction attempts
later when "overflow" is detected.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reported-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes #10765
2020-08-25 14:33:36 -07:00
Ryan Moeller b596585fd9
man: Canonicalize .TH usage
* Use all caps for document title.
* Remove section name as it can be inferred from the section number.
* Name "OpenZFS" as the document source.
* Bump modification date.

While here, fixed trailing whitespace reported by igor.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10792
2020-08-24 21:25:28 -07:00
Chris McDonough 07ce8961e5
Improve documentation of zpool import -d/-c vs -s
Specify that, by default, zpool import uses the libblkid
cache on Linux and geom on FreeBSD, and only scans when
-d/-s is provided.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Signed-off-by: Chris McDonough <chrism@plope.com>
Closes #7656
Closes #10771
2020-08-23 21:18:30 -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
Ryan Moeller 6706552ea6
Remove hard coded "Linux" OS from manpages
The recommended practice for `.Os` on FreeBSD is to not specify any
arguments.  The correct OS name is used automatically.

Oddly enough, on the Linux distro I tested this on (CentOS 7), the man
pager defaulted to displaying "BSD" as the OS rather than "Linux".  To
accommodate this, tack " Linux" back on in an install hook on Linux.
This is much simpler than removing it for FreeBSD when vendored in the
base system.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10760
2020-08-21 11:55:47 -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
Ryan Moeller 009cc8e884
Make zc_nvlist_src_size limit tunable
We limit the size of nvlists passed to the kernel so a user cannot make
the kernel do an unreasonably large allocation.  On FreeBSD this limit
was 128 kiB, which turns out to be a bit too small when doing some
operations involving a large number of datasets or snapshots, for
example replication.

Make this limit tunable, with a platform-specific auto default.
Linux keeps its limit at KMALLOC_MAX_SIZE. FreeBSD uses 1/4 of the
system limit on user wired memory, which allows it to scale depending
on system configuration.

Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Issue #6572 
Closes #10706
2020-08-18 09:33:55 -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 994de7e4b7
Remove KMC_KMEM and KMC_VMEM
`KMC_KMEM` and `KMC_VMEM` are now unused since all SPL-implemented
caches are `KMC_KVMEM`.

KMC_KMEM: Given the default value of `spl_kmem_cache_kmem_limit`, we
don't use kmalloc to back the SPL caches, instead we use kvmalloc
(KMC_KVMEM).  The flag, module parameter, /proc entries, and associated
code are removed.

KMC_VMEM: This flag is not used, and kvmalloc() is always preferable to
vmalloc().  The flag, /proc entries, and associated code are removed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10673
2020-08-17 16:04:28 -07:00
Matthew Ahrens 3442c2a02d
Revise ARC shrinker algorithm
The ARC shrinker callback `arc_shrinker_count/_scan()` is invoked by the
kernel's shrinker mechanism when the system is running low on free
pages.  This happens via 2 code paths:

1. "direct reclaim": The system is attempting to allocate a page, but we
are low on memory.  The ARC shrinker callback is invoked from the
page-allocation code path.

2. "indirect reclaim": kswapd notices that there aren't many free pages,
so it invokes the ARC shrinker callback.

In both cases, the kernel's shrinker code requests that the ARC shrinker
callback release some of its cache, and then it measures how many pages
were released.  However, it's measurement of released pages does not
include pages that are freed via `__free_pages()`, which is how the ARC
releases memory (via `abd_free_chunks()`).  Rather, the kernel shrinker
code is looking for pages to be placed on the lists of reclaimable pages
(which is separate from actually-free pages).

Because the kernel shrinker code doesn't detect that the ARC has
released pages, it may call the ARC shrinker callback many times,
resulting in the ARC "collapsing" down to `arc_c_min`.  This has several
negative impacts:

1. ZFS doesn't use RAM to cache data effectively.

2. In the direct reclaim case, a single page allocation may wait a long
time (e.g. more than a minute) while we evict the entire ARC.

3. Even with the improvements made in 67c0f0dedc ("ARC shrinking blocks
reads/writes"), occasionally `arc_size` may stay above `arc_c` for the
entire time of the ARC collapse, thus blocking ZFS read/write operations
in `arc_get_data_impl()`.

To address these issues, this commit limits the ways that the ARC
shrinker callback can be used by the kernel shrinker code, and mitigates
the impact of arc_is_overflowing() on ZFS read/write operations.

With this commit:

1. We limit the amount of data that can be reclaimed from the ARC via
the "direct reclaim" shrinker.  This limits the amount of time it takes
to allocate a single page.

2. We do not allow the ARC to shrink via kswapd (indirect reclaim).
Instead we rely on `arc_evict_zthr` to monitor free memory and reduce
the ARC target size to keep sufficient free memory in the system.  Note
that we can't simply rely on limiting the amount that we reclaim at once
(as for the direct reclaim case), because kswapd's "boosted" logic can
invoke the callback an unlimited number of times (see
`balance_pgdat()`).

3. When `arc_is_overflowing()` and we want to allocate memory,
`arc_get_data_impl()` will wait only for a multiple of the requested
amount of data to be evicted, rather than waiting for the ARC to no
longer be overflowing.  This allows ZFS reads/writes to make progress
even while the ARC is overflowing, while also ensuring that the eviction
thread makes progress towards reducing the total amount of memory used
by the ARC.

4. The amount of memory that the ARC always tries to keep free for the
rest of the system, `arc_sys_free` is increased.

5. Now that the shrinker callback is able to provide feedback to the
kernel's shrinker code about our progress, we can safely enable
the kswapd hook. This will allow the arc to receive notifications
when memory pressure is first detected by the kernel. We also
re-enable the appropriate kstats to track these callbacks.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10600
2020-07-31 21:10:52 -07:00
Ryan Moeller 8348fac30c
Limit dbuf cache sizes based only on ARC target size by default
Set the initial max sizes to ULONG_MAX to allow the caches to grow
with the ARC.

Recalculate the metadata cache size on demand so it can adapt, too.

Update descriptions in zfs-module-parameters(5).

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10563 
Closes #10610
2020-07-24 20:38:48 -07:00
tony-zfs 02fced3067
Add support to decode a resume token
Adding a new subcommand to zstream called token. This
now allows users to decode a resume token to retrieve the toname
field. This can be useful for tools that need this information.
The syntax works as follows zstream token <resume_token>.

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Paul Zuchowski <pzuchowski@datto.com>
Signed-off-by: Tony Perkins <tperkins@datto.com>
Closes #10558
2020-07-23 17:44:03 -07:00
Matthew Ahrens 6774931dfa
Extend zdb to print inconsistencies in livelists and metaslabs
Livelists and spacemaps are data structures that are logs of allocations
and frees.  Livelists entries are block pointers (blkptr_t). Spacemaps
entries are ranges of numbers, most often used as to track
allocated/freed regions of metaslabs/vdevs.

These data structures can become self-inconsistent, for example if a
block or range can be "double allocated" (two allocation records without
an intervening free) or "double freed" (two free records without an
intervening allocation).

ZDB (as well as zfs running in the kernel) can detect these
inconsistencies when loading livelists and metaslab.  However, it
generally halts processing when the error is detected.

When analyzing an on-disk problem, we often want to know the entire set
of inconsistencies, which is not possible with the current behavior.
This commit adds a new flag, `zdb -y`, which analyzes the livelist and
metaslab data structures and displays all of their inconsistencies.
Note that this is different from the leak detection performed by
`zdb -b`, which checks for inconsistencies between the spacemaps and the
tree of block pointers, but assumes the spacemaps are self-consistent.

The specific checks added are:

Verify livelists by iterating through each sublivelists and:
- report leftover FREEs
- report double ALLOCs and double FREEs
- record leftover ALLOCs together with their TXG [see Cross Check]

Verify spacemaps by iterating over each metaslab and:
- iterate over spacemap and then the metaslab's entries in the
  spacemap log, then report any double FREEs and double ALLOCs

Verify that livelists are consistenet with spacemaps.  The space
referenced by livelists (after using the FREE's to cancel out
corresponding ALLOCs) should be allocated, according to the spacemaps.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
External-issue: DLPX-66031
Closes #10515
2020-07-14 17:51:05 -07:00
Arvind Sankar 38e2e9ce83 Centralize variable substitution
A bunch of places need to edit files to incorporate the configured paths
i.e. bindir, sbindir etc. Move this logic into a common file.

Create arc_summary by copying arc_summary[23] as appropriate at build
time instead of install time.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10559
2020-07-14 17:33:44 -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
Matthew Ahrens 7b232e9354
arcstat: add 'avail', fix 'free'
The meaning of the `free` field is currently `zfs_arc_sys_free`, which
is the target amount of memory to leave free for the system, and is
constant after booting.

This commit changes the meaning of `free` to arc_free_memory(), the
amount of memory that the ARC considers to be free.

It also adds a new arcstat field `avail`, which tracks
`arc_available_memory()`.

Since `avail` can be negative, it also updates the arcstat script to
pretty-print negative values.

example output:

  $ arcstat -f time,miss,arcsz,c,grow,need,free,avail 1
      time  miss  arcsz     c  grow  need  free  avail
  15:03:02   39K   114G  114G     0     0  2.4G  407M
  15:03:03   42K   114G  114G     0     0  2.1G  120M
  15:03:04   40K   114G  114G     0     0  1.8G  -177M
  15:03:05   24K   113G  112G     0     0  1.7G  -269M
  15:03:06   29K   111G  110G     0     0  1.6G  -385M
  15:03:07   27K   110G  108G     0     0  1.4G  -535M
  15:03:08   13K   108G  108G     0     0  2.2G  239M
  15:03:09   33K   107G  107G     0     0  1.3G  -639M
  15:03:10   16K   105G  102G     0     0  2.6G  704M
  15:03:11  7.2K   102G  102G     0     0  5.1G  3.1G
  15:03:12   42K   103G  102G     0     0  4.8G  2.8G

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10494
2020-06-26 18:05:28 -07:00
Arvind Sankar 6b99fc0620 Fixes for make dist
Reduce the usage of EXTRA_DIST. If files are conditionally included in
_SOURCES, _HEADERS etc, automake is smart enough to dist all files that
could possibly be included, but this does not apply to EXTRA_DIST,
resulting in make dist depending on the configuration.

Add some files that were missing altogether in various Makefile's.

The changes to disted files in this commit (excluding deleted files):

+./cmd/zed/agents/README.md
+./etc/init.d/README.md
+./lib/libspl/os/freebsd/getexecname.c
+./lib/libspl/os/freebsd/gethostid.c
+./lib/libspl/os/freebsd/getmntany.c
+./lib/libspl/os/freebsd/mnttab.c
-./lib/libzfs/libzfs_core.pc
-./lib/libzfs/libzfs.pc
+./lib/libzfs/os/freebsd/libzfs_compat.c
+./lib/libzfs/os/freebsd/libzfs_fsshare.c
+./lib/libzfs/os/freebsd/libzfs_ioctl_compat.c
+./lib/libzfs/os/freebsd/libzfs_zmount.c
+./lib/libzutil/os/freebsd/zutil_compat.c
+./lib/libzutil/os/freebsd/zutil_device_path_os.c
+./lib/libzutil/os/freebsd/zutil_import_os.c
+./module/lua/README.zfs
+./module/os/linux/spl/README.md
+./tests/README.md
+./tests/zfs-tests/tests/functional/cli_root/zfs_clone/zfs_clone_rm_nested.ksh
+./tests/zfs-tests/tests/functional/cli_root/zfs_send/zfs_send_encrypted_unloaded.ksh
+./tests/zfs-tests/tests/functional/inheritance/README.config
+./tests/zfs-tests/tests/functional/inheritance/README.state
+./tests/zfs-tests/tests/functional/rsend/rsend_016_neg.ksh
+./tests/zfs-tests/tests/perf/fio/sequential_readwrite.fio

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10501
2020-06-26 14:20:02 -07:00
Jorgen Lundman 68301ba20e
zed additional features
This commit adds two features to zed, that macOS desires. The first
is that when you unload the kernel module, zed would enter into a
cpubusy loop calling zfs_events_next() repeatedly. We now look for
ENODEV, returned by kernel, so zed can exit gracefully.

Second feature is -I (idle) (alas -P persist was taken) is for the
deamon to;

1; if started without ZFS kernel module, stick around waiting for it.
2; if kernel module is unloaded, go back to 1.

This is due to daemons in macOS is started by launchctl, and is
expected to stick around.

Currently, the busy loop only exists when errno is ENODEV. This is
to ensure that functionality that upstream expects is not changed.
It did not care about errors before, and it still does not. (with the
exception of ENODEV).

However, it is probably better that all errors
(ERESTART notwithstanding) exits the loop, and the issues complaining
about zed taking all CPU will go away.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes #10476
2020-06-22 09:53:34 -07:00
adilger f734301d22
linux: add basic fallocate(mode=0/2) compatibility
Implement semi-compatible functionality for mode=0 (preallocation)
and mode=FALLOC_FL_KEEP_SIZE (preallocation beyond EOF) for ZPL.

Since ZFS does COW and snapshots, preallocating blocks for a file
cannot guarantee that writes to the file will not run out of space.
Even if the first overwrite was guaranteed, it would not handle any
later overwrite of blocks due to COW, so strict compliance is futile.
Instead, make a best-effort check that at least enough free space is
currently available in the pool (with a bit of margin), then create
a sparse file of the requested size and continue on with life.

This does not handle all cases (e.g. several fallocate() calls before
writing into the files when the filesystem is nearly full), which
would require a more complex mechanism to be implemented, probably
based on a modified version of dmu_prealloc(), but is usable as-is.

A new module option zfs_fallocate_reserve_percent is used to control
the reserve margin for any single fallocate call.  By default, this
is 110% of the requested preallocation size, so an additional 10% of
available space is reserved for overhead to allow the application a
good chance of finishing the write when the fallocate() succeeds.
If the heuristics of this basic fallocate implementation are not
desirable, the old non-functional behavior of returning EOPNOTSUPP
for calls can be restored by setting zfs_fallocate_reserve_percent=0.

The parameter of zfs_statvfs() is changed to take an inode instead
of a dentry, since no dentry is available in zfs_fallocate_common().

A few tests from @behlendorf cover basic fallocate functionality.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Issue #326
Closes #10408
2020-06-18 11:22:11 -07:00
Grischa Zengel 059f7c20e3
man.8: Add bookmark to list of types
While checking bash_completion I missed bookmark as type.

```
# zfs get type zpool2#b
NAME      PROPERTY  VALUE     SOURCE
zpool2#b  type      bookmark  -
```

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Grischa Zengel <github.zfsonlinux@zengel.info>
Closes #10419
2020-06-10 17:53:07 -07:00
Matthew Ahrens f66434268c
Remove unnecessary references to slavery
The horrible effects of human slavery continue to impact society.  The
casual use of the term "slave" in computer software is an unnecessary
reference to a painful human experience.

This commit removes all possible references to the term "slave".

Implementation notes:

The zpool.d/slaves script is renamed to dm-deps, which uses the same
terminology as `dmsetup deps`.

References to the `/sys/class/block/$dev/slaves` directory remain.  This
directory name is determined by the Linux kernel.  Although
`dmsetup deps` provides the same information, it unfortunately requires
elevated privileges, whereas the `/sys/...` directory is world-readable.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10435
2020-06-10 17:07:59 -07:00
Andrea Gelmini dd4bc569b9
Fix typos
Correct various typos in the comments and tests.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes #10423
2020-06-09 21:24:09 -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
felixdoerre 501a1511ae
mount: use the mount syscall directly
Allow zfs datasets to be mounted on Linux without relying on the
invocation of an external processes.  This is the same behavior
which is implemented for FreeBSD.

Use of the libmount library was originally considered because it 
provides functionality to properly lock and update the /etc/mtab 
file.  However, these days /etc/mtab is typically a symlink to 
/proc/self/mounts so there's nothing to updated.  Therefore, we
call mount(2) directly and avoid any additional dependencies. 

If required the legacy behavior can be enabled by setting the 
ZFS_MOUNT_HELPER environment variable.  This may be needed in
environments where SELinux in enabled and the zfs binary does  
not have mount permission.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Felix Dörre <felix@dogcraft.de>
#10294
2020-05-20 18:02:41 -07:00
Paul Dagnelie de4f06c275
Small program that converts a dataset id and an object id to a path
Small program that converts a dataset id and an object id to a path

Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #10204
2020-05-20 10:05:33 -07:00
AJ Jordan 5a04b17717 Fix up arcstat(1) to match our version
Turns out the illumos manpage, which is what this originates from, was
written for the original Perl version of the utility which is not the
version in the OpenZFS tree. *That* version originates from a Python
rewrite that was done for FreeNAS. So fix up the manpage to match what
we actually ship (and fix a few typos in the process).

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: AJ Jordan <alex@strugee.net>
Closes #10288
2020-05-11 16:22:48 -07:00
AJ Jordan ac806a2559 Import the arcstat(1m) manpage from illumos
And move it from section 1m to section 1 for consistency.

Imported from illumos commit f34d737f.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: AJ Jordan <alex@strugee.net>
Closes #10288
2020-05-11 16:22:18 -07:00
George Amanakis 657fd33bcf
Improvements on persistent L2ARC
Functional changes:

We implement refcounts of log blocks and their aligned size on the
cache device along with two corresponding arcstats. The refcounts are
reflected in the header of the device and provide valuable information
as to whether log blocks are accounted for correctly. These are
dynamically adjusted as log blocks are committed/evicted. zdb also uses
this information in the device header and compares it to the
corresponding values as reported by dump_l2arc_log_blocks() which
emulates l2arc_rebuild(). If the refcounts saved in the device header
report higher values, zdb exits with an error. For this feature to work
correctly there should be no active writes on the device. This is also
employed in the tests of persistent L2ARC. We extend the structure of
the cache device header by adding the two new variables mirroring the
refcounts after the existing variables to preserve backward
compatibility in terms of persistent L2ARC.

1) a new arcstat "l2_log_blk_asize" and refcount "l2ad_lb_asize" which
   reflect the total aligned size of log blocks on the device. This is
   also reflected in the header of the cache device as "dh_lb_asize".
2) a new arcstat "l2arc_log_blk_count" and refcount "l2ad_lb_count"
   which reflect the total number of L2ARC log blocks present on cache
   devices.  It is also reflected in the header of the cache device as
   "dh_lb_count".

In l2arc_rebuild_vdev() if the amount of committed log entries in a log
block is 0 and the device header is valid we update the device header.
This will facilitate trimming of the whole device in this case when
TRIM for L2ARC is implemented.

Improve loop protection in l2arc_rebuild() by using the starting offset
of the payload of each log block instead of the starting offset of the
log block.

If the zio in l2arc_write_buffers() fails, restore the lbps array in the
header of the device to its previous state in l2arc_write_done().

If l2arc_rebuild() ends the rebuild process without restoring any L2ARC
log blocks in ARC and without any other error, this means that the lbps
array in the header is pointing to non-existent or invalid log blocks.
Reset the device header in this case.

In l2arc_rebuild() change the zfs_dbgmsg messages to
spa_history_log_internal() making them user visible with zpool history
command.

Non-functional changes:

Make the first test in persistent L2ARC use `zdb -lll` to increase
coverage in `zdb.c`.

Rename psize with asize when referring to log blocks, since
L2ARC_SET_PSIZE stores the vdev aligned size for log blocks. Also
rename dh_log_blk_entries to dh_log_entries to make it clear that
it is a mirror of l2ad_log_entries. Added comments for both changes.

Fix inaccurate comments for example in l2arc_log_blk_restore().

Add asserts at the end in l2arc_evict() and l2arc_write_buffers().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes #10228
2020-05-07 16:34:03 -07:00
Paul B. Henson 7bf3e1fa0f OpenZFS 3254 - add support in zfs for aclmode=restricted
Authored-by: Paul B. Henson <henson@acm.org>
Reviewed by: Albert Lee <trisk@nexenta.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Paul B. Henson <henson@acm.org>

OpenZFS-issue: https://www.illumos.org/issues/3254
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/71dbfc287c
Closes #10266
2020-04-30 11:23:59 -07:00
Paul B. Henson a1af567bb6 OpenZFS 742 - Resurrect the ZFS "aclmode" property OpenZFS 664 - Umask masking "deny" ACL entries OpenZFS 279 - Bug in the new ACL (post-PSARC/2010/029) semantics
Porting notes:
* Updated zfs_acl_chmod to take 'boolean_t isdir' as first parameter
  rather than 'zfsvfs_t *zfsvfs'
* zfs man pages changes mixed between zfs and new zfsprops man pages

Reviewed by: Aram Hvrneanu <aram@nexenta.com>
Reviewed by: Gordon Ross <gwr@nexenta.com>
Reviewed by: Robert Gordon <rbg@openrbg.com>
Reviewed by: Mark.Maybee@oracle.com
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@nexenta.com>
Ported-by: Paul B. Henson <henson@acm.org>

OpenZFS-issue: https://www.illumos.org/issues/742
OpenZFS-issue: https://www.illumos.org/issues/664
OpenZFS-issue: https://www.illumos.org/issues/279
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/a3c49ce110
Closes #10266
2020-04-30 11:22:45 -07:00
alex 47c9299fcc
zfs_create: round up volume size to multiple of bs
Round up the volume size requested in `zfs create -V size` to the next
higher multiple of the volblocksize. Updates the man page and adds a
test to verify the new behavior.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reported-by: puffi <puffi@users.noreply.github.com>
Signed-off-by: Alex John <alex@stty.io>
Closes #8541 
Closes #10196
2020-04-24 19:04:34 -07:00
Matthew Ahrens 196bee4cfd
Remove deduplicated send/receive code
Deduplicated send streams (i.e. `zfs send -D` and `zfs receive` of such
streams) are deprecated.  Deduplicated send streams can be received by
first converting them to non-deduplicated with the `zstream redup`
command.

This commit removes the code for sending and receiving deduplicated send
streams.  `zfs send -D` will now print a warning, ignore the `-D` flag,
and generate a regular (non-deduplicated) send stream.  `zfs receive` of
a deduplicated send stream will print an error message and fail.

The resulting code simplification (especially in the kernel's support
for receiving dedup streams) should help enable future performance
enhancements.

Several new tests are added which leverage `zstream redup`.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #7887
Issue #10117
Issue #10156
Closes #10212
2020-04-23 10:06:57 -07:00
Matthew Ahrens c618f87cd2
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated.  To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.

The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand.  The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.

The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.

Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)

For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).

For WRITE_BYREF records, we change them to WRITE records.  We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file.  This is why the stream can not be a pipe.  The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).

This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`).  A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124 
Closes #10156
2020-04-10 10:39:55 -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
Paul Dagnelie 5a42ef04fd
Add 'zfs wait' command
Add a mechanism to wait for delete queue to drain.

When doing redacted send/recv, many workflows involve deleting files 
that contain sensitive data. Because of the way zfs handles file 
deletions, snapshots taken quickly after a rm operation can sometimes 
still contain the file in question, especially if the file is very 
large. This can result in issues for redacted send/recv users who 
expect the deleted files to be redacted in the send streams, and not 
appear in their clones.

This change duplicates much of the zpool wait related logic into a 
zfs wait command, which can be used to wait until the internal
deleteq has been drained.  Additional wait activities may be added 
in the future. 

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Gallagher <john.gallagher@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes #9707
2020-04-01 10:02:06 -07:00
Ryan Moeller 9a51738b60
Let default arc_c_max be platform dependent
Linux changed the default max ARC size to 1/2 of physical memory to
deal with shortcomings of the Linux SLUB allocator.  Other platforms
do not require the same logic.

Implement an arc_default_max() function to determine a default max ARC
size in platform code.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10155
2020-03-27 09:14:46 -07:00
Matthew Ahrens 652bdc9b0e
Deprecate deduplicated send streams
Dedup send can only deduplicate over the set of blocks in the send
command being invoked, and it does not take advantage of the dedup table
to do so. This is a very common misconception among not only users, but
developers, and makes the feature seem more useful than it is. As a
result, many users are using the feature but not getting any benefit
from it.

Dedup send requires a nontrivial expenditure of memory and CPU to
operate, especially if the dataset(s) being sent is (are) not already
using a dedup-strength checksum.

Dedup send adds developer burden. It expands the test matrix when
developing new features, causing bugs in released code, and delaying
development efforts by forcing more testing to be done.

As a result, we are deprecating the use of `zfs send -D` and receiving
of such streams.  This change adds a warning to the man page, and also
prints the warning whenever dedup send or receive are used.

In a future release, we plan to:
1. remove the kernel code for generating deduplicated streams
2. make `zfs send -D` generate regular, non-deduplicated streams
3. remove the kernel code for receiving deduplicated streams
4. make `zfs receive` of deduplicated streams process them in userland
   to "re-duplicate" them, so that they can still be received.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #7887 
Closes #10117
2020-03-18 13:31:10 -07:00
Mariusz Zaborski a57d3d45d6
Add option for forcible unmounting dataset while receiving snapshot.
Currently when the dataset is in use we can't receive snapshots.

    zfs send test/1@asd | zfs recv -FM test/2
    cannot unmount '/test/2': Device busy

This commits add option 'M' which attempts to forcibly unmount the
dataset.  Thanks to this we can enforce receiving snapshots in a
single step.

Note that this functionality is not supported on Linux because the
VFS will prevent active mounted filesystems from being unmounted,
even with the force option.  This is the intended VFS behavior.

Test cases were added to verify the expected behavior based on
the platform.

Discussed-with: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allanjude@freebsd.org>
External-issue: https://reviews.freebsd.org/D22306
Closes #9904
2020-03-17 10:08:32 -07:00
Matthew Ahrens 7261fc2e81
Improve zfs receive performance by batching writes
For each WRITE record in the stream, `zfs receive` creates a DMU
transaction (`dmu_tx_create()`) and writes this block's data into the
object.  If per-block overheads (as opposed to per-byte overheads)
dominate performance (as is often the case with small recordsize), the
per-dmu-transaction overheads can be significant.  For example, in some
workloads the `receieve_writer` thread is 100% on CPU, and more than
half of its CPU time is in these per-tx routines (e.g.
dmu_tx_hold_write, dmu_tx_assign, dmu_tx_commit).

To improve performance of `zfs receive`, this commit batches WRITE
records which are to nearby offsets of the same object, and uses one DMU
transaction to write them all.  By default the batch size is 1MB, which
for recordsize=8K reduces the number of DMU transactions by 128x for
full send streams (incrementals will depend on how "clumpy" the changed
blocks are).

This commit improves the performance of `dd if=stream | zfs recv`
from 78,800 blocks/sec to 98,100 blocks/sec (25% improvement).

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10099
2020-03-16 11:51:56 -07:00
Ryan Moeller f5f6fb03b7
Change default to overlay=on
Filesystems allow overlay mounts by default on FreeBSD and Linux.

Respect the native convention by switching the default to overlay=on,
while retaining the option to turn the property off for compatibility
with other operating systems' conventions.

Update documentation and tests accordingly.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10030
2020-03-06 09:28:19 -08:00
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
Mariusz Zaborski 89adffb7bc
Add notice that forcefully unmount is not supported on Linux
The Linux VFS will never allow a filesystem which is in use to
be unmounted.  This behavior differs from other platforms like
FreeBSD which allow a filesystem to be force unmounted.  This 
will result in errors being returned to applications actively
using the filesystem.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <oshogbo@vexillium.org>
Closes #10013
2020-02-18 13:36:23 -08:00
Richard Laager f244846462
Prefer org.openzfs for features and properties
Moving forward, we wish to use org.openzfs (no dash) rather than
org.open-zfs or org.zfsonlinux for feature GUIDs and property names.
The existing feature GUIDs cannot be changed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Closes #10003
2020-02-18 09:36:50 -08:00
InsanePrawn ecbbdac799 Systemd mount generator: Generate noauto units; add control properties
This commit refactors the systemd mount generators and makes the
following major changes:

- The generator now generates units for datasets marked canmount=noauto,
  too. These units are NOT WantedBy local-fs.target.
  If there are multiple noauto datasets for a path, no noauto unit will
  be created. Datasets with canmount=on are prioritized.

- Introduces handling of new user properties which are now included in
  the zfs-list.cache files:
    - org.openzfs.systemd:requires:
      List of units to require for this mount unit
    - org.openzfs.systemd:requires-mounts-for:
      List of mounts to require by this mount unit
    - org.openzfs.systemd:before:
      List of units to order after this mount unit
    - org.openzfs.systemd:after:
      List of units to order before this mount unit
    - org.openzfs.systemd:wanted-by:
      List of units to add a Wants dependency on this mount unit to
    - org.openzfs.systemd:required-by:
      List of units to add a Requires dependency on this mount unit to
    - org.openzfs.systemd:nofail:
      Toggles between a wants and a requires dependency.
    - org.openzfs.systemd:ignore:
      Do not generate a mount unit for this dataset.

  Consult the updated man page for detailed documentation.

- Restructures and extends the zfs-mount-generator(8) man page with the
  above properties, information on unit ordering and a license header.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Antonio Russo <antonio.e.russo@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: InsanePrawn <insane.prawny@gmail.com>
Closes #9649
2020-02-14 15:32:55 -08:00
Jason King 13b5a4d5c0
Support setting user properties in a channel program
This adds support for setting user properties in a
zfs channel program by adding 'zfs.sync.set_prop'
and 'zfs.check.set_prop' to the ZFS LUA API.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Co-authored-by: Sara Hartse <sara.hartse@delphix.com>
Contributions-by: Jason King <jason.king@joyent.com>
Signed-off-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Jason King <jason.king@joyent.com>
Closes #9950
2020-02-14 13:41:42 -08:00
Matthew Ahrens 4fe3a842bb
Remove limit on number of async zio_frees of non-dedup blocks
The module parameter zfs_async_block_max_blocks limits the number of
blocks that can be freed by the background freeing of filesystems and
snapshots (from "zfs destroy"), in one TXG.  This is useful when freeing
dedup blocks, becuase each zio_free() of a dedup block can require an
i/o to read the relevant part of the dedup table (DDT), and will also
dirty that block.

zfs_async_block_max_blocks is set to 100,000 by default.  For the more
typical case where dedup is not used, this can have a negative
performance impact on the rate of background freeing (from "zfs
destroy").  For example, with recordsize=8k, and TXG's syncing once
every 5 seconds, we can free only 160MB of data per second, which may be
much less than the rate we can write data.

This change increases zfs_async_block_max_blocks to be unlimited by
default.  To address the dedup freeing issue, a new tunable is
introduced, zfs_max_async_dedup_frees, which limits the number of
zio_free()'s of dedup blocks done by background destroys, per txg.  The
default is 100,000 free's (same as the old zfs_async_block_max_blocks
default).

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10000
2020-02-14 08:39:46 -08:00