ZFS_READONLY represents the "DOS R/O" attribute.
When that flag is set, we should behave as if write access
were not granted by anything in the ACL. In particular:
We _must_ allow writes after opening the file r/w, then
setting the DOS R/O attribute, and writing some more.
(Similar to how you can write after fchmod(fd, 0444).)
Restore these semantics which were lost on FreeBSD when refactoring
zfs_write. To my knowledge Linux does not actually expose this flag,
but we'll need it to eventually so I've added the supporting checks.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11693
When populating a ZIL destination buffer ensure it is always
zeroed before its contents are constructed.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tom Caputi <caputit1@tcnj.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11687
Even when supplied with an abd to abd_get_offset_struct(), the call
to abd_get_offset_impl() can allocate a different abd. Ensure to
call abd_fini_struct() on the abd that is not used.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#11683
Wire up the --enable-debug flag for configure to the FreeBSD module
build. Add --enable-invariants.
The running FreeBSD kernel config is used to detect whether to enable
INVARIANTS if not explicitly specified with --enable-invariants or
--disable-invariants.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11678
The spl_kmem_alloc showed up in some flamegraphs in a single-threaded
4k sync write workload at 85k IOPS on an
Intel(R) Xeon(R) Silver 4215 CPU @ 2.50GHz.
Certainly not a huge win but I believe the change is clean and
easy to maintain down the road.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes#11666
This value does work as expected, and is documented in the manpage.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jake Howard <git@theorangeone.net>
Closes#11670
When a device which is actively trimming or initializing becomes
FAULTED, and therefore no longer writable, cancel the active
TRIM or initialization. When the device is merely taken offline
with `zpool offline` then stop the operation but do not cancel it.
When the device is brought back online the operation will be
resumed if possible.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Vipin Kumar Verma <vipin.verma@hpe.com>
Signed-off-by: Srikanth N S <srikanth.nagasubbaraoseetharaman@hpe.com>
Closes#11588
The function has three similar pieces of code: for read-behind pages,
requested pages and read-ahead pages. All three pieces had an
assert to ensure that the page is not mapped. Later the assert was
relaxed to require that the page is not mapped for writing. But that
was done in two places out of three. This change fixes the third piece,
read-ahead.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Closes#11654
After 35ec517 it has become possible to import ZFS pools witn an
active org.illumos:edonr feature on FreeBSD, leading to a panic.
In addition, "zpool status" reported all pools without edonr
as upgradable and "zpool upgrade -v" reported edonr in the list
of upgradable features.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes#11653
The struct bio member bi_disk was moved underneath a new member named
bi_bdev. So all attempts to reference bio->bi_disk need to now become
bio->bi_bdev->bd_disk.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#11639
The metaslab_disable() call may block waiting for a txg sync.
Therefore it's important that vdev_rebuild_thread release the
SCL_CONFIG read lock it is holding before this call. Failure
to do so can result in the txg_sync thread getting blocked
waiting for this lock which results in a deadlock.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewd-by: Srikanth N S <srikanth.nagasubbaraoseetharaman@hpe.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11647
Calling vdev_free() only requires the we acquire the spa config
SCL_STATE_ALL locks, not the SCL_ALL locks. In particular, we need
need to avoid taking the SCL_CONFIG lock (included in SCL_ALL) as a
writer since this can lead to a deadlock. The txg_sync_thread() may
block in spa_txg_history_init_io() when taking the SCL_CONFIG lock
as a reading when it detects there's a pending writer.
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11585
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#6572Closes#11638
This change modifies the behavior of how we determine how much slop
space to use in the pool, such that now it has an upper limit. The
default upper limit is 128G, but is configurable via a tunable.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes#11023
This prevents a panic after a SLOG add/removal on the root pool followed
by a zpool scrub.
When a SLOG is removed, a hole takes its place - the vdev_ops for a hole
is vdev_hole_ops, which defines the handler functions of vdev_op_hold
and vdev_op_rele as NULL.
This bug has been reported in illumos and FreeBSD, a different trigger
in the FreeBSD report though.
Credit for this patch goes to Patrick Mooney <pmooney@pfmooney.com>
Obtained from: illumos-gate commit: c65bd18728f34725
External-issue: https://www.illumos.org/issues/12981
External-issue: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252396
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Wing <rob.fx907@gmail.com>
Closes#11623
Making uio_impl.h the common header interface between Linux and FreeBSD
so both OS's can share a common header file. This also helps reduce code
duplication for zfs_uio_t for each OS.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11622
Fix regression seen in issue #11545 where checksum errors
where not being counted or showing up in a zpool event.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#11609
First, the crypto request completion handler contains a bug in that it
fails to reset fs_done correctly after the request is completed. This
is only a problem for asynchronous drivers. Second, some hardware
drivers have input constraints which ZFS does not satisfy. For
instance, ccp(4) apparently requires the AAD length for AES-GCM to be a
multiple of the cipher block size, and with qat(4) the AES-GCM AAD
length may not be longer than 240 bytes. FreeBSD's generic crypto
framework doesn't have a mechanism to automatically fall back to a
software implementation if a hardware driver cannot process a request,
and ZFS does not tolerate such errors.
The plan is to implement such a fallback mechanism, but with FreeBSD
13.0 approaching we should simply disable the use hardware drivers for
now.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#11612
Remove function that become unused after refactoring in
e2af2acce3.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Libby <rlibby@FreeBSD.org>
Closes#11614
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
Rather than conditionally compiling out the edonr code for FreeBSD
update zfs_mod_supported_feature() to indicate this feature is
unsupported. This ensures that all spa features are defined on
every platform, even if they are not supported.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11605
Issue #11468
zfs_znode_update_vfs is a more platform-agnostic name than
zfs_inode_update. Besides that, the function's prototype is moved to
include/sys/zfs_znode.h as the function is also used in common code.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ka Ho Ng <khng300@gmail.com>
Sponsored by: The FreeBSD Foundation
Closes#11580
The first time through the loop prevdb and prevhdl are NULL. They
are then both set, but only prevdb is checked. Add an ASSERT to
make it clear that prevhdl must be set when prevdb is.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Kleber <klebertarcisio@yahoo.com.br>
Closes#10754Closes#11575
3d40b65 refactored zfs_vnops.c, which shared much code verbatim between
Linux and BSD. After a successful write, the suid/sgid bits are reset,
and the mode to be written is stored in newmode. On Linux, this was
propagated to both the in-memory inode and znode, which is then updated
with sa_update.
3d40b65 accidentally removed the initialization of newmode, which
happened to occur on the same line as the inode update (which has been
moved out of the function).
The uninitialized newmode can be saved to disk, leading to a crash on
stat() of that file, in addition to a merely incorrect file mode.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes#11474Closes#11576
Expand the comments to make it clear exactly what is guaranteed
by dmu_tx_assign() and txg_hold_open(). Additionally, update
the comment which refers to txg_exit() when it should reference
txg_rele_to_sync().
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Christian Schwarz <me@cschwarz.com>
Closes#11521
ABD's currently track their parent/child relationship. This applies to
`abd_get_offset()` and `abd_borrow_buf()`. However, nothing depends on
knowing this relationship, it's only used for consistency checks to
verify that we are not destroying an ABD that's still in use. When we
are creating/destroying ABD's frequently, the performance impact of
maintaining these data structures (in particular the atomic
increment/decrement operations) can be measurable.
This commit removes this verification code on production builds, but
keeps it when ZFS_DEBUG is set.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11535
I originally applied a fix in #11539 to fix a parent's child references
when a gang ABD is free'd. However, I did not take into account
abd_gang_add_gang(). We still need to make sure to update the child
references in this function as well. In order to resolve this I removed
decreasing the gang ABD's size in abd_free_gang() as well as moved back
the original placeent of zfs_refcount_remove_many() in abd_free().
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11542
`__vdev_disk_physio()` uses `abd_nr_pages_off()` to allocate a bio with
a sufficient number of iovec's to process this zio (i.e.
`nr_iovecs`/`bi_max_vecs`). If there are not enough iovec's in the bio,
then additional bio's will be allocated. However, this is a sub-optimal
code path. In particular, it requires several abd calls (to
`abd_nr_pages_off()` and `abd_bio_map_off()`) which will have to walk
the constituents of the ABD (the pages or the gang children) because
they are looking for offsets > 0.
For gang ABD's, `abd_nr_pages_off()` returns the number of iovec's
needed for the first constituent, rather than the sum of all
constituents (within the requested range). This always under-estimates
the required number of iovec's, which causes us to always need several
bio's. The end result is that `__vdev_disk_physio()` is usually O(n^2)
for gang ABD's (and occasionally O(n^3), when more than 16 bio's are
needed).
This commit fixes `abd_nr_pages_off()`'s handling of gang ABD's, to
correctly determine how many iovec's are needed, by adding up the number
of iovec's for each of the gang children in the requested range.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11536
If we do not write any buffers to the cache device and the evict hand
has not advanced do not update the cache device header.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#11522Closes#11537
Moving the call to zfs_refcount_remove_many() in abd_free() to be called
before any of the ABD free variants are called. This is necessary
because abd_free_gang() adjusts the abd_size for the gang ABD. If the
parent's child references are removed after free'ing the gang ABD the
refcount is not adjusted correctly for the parent's children.
I also removed some stray abd_put() in comments and changed
abd_free_gang_abd() -> abd_free_gang().
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11539
Before a hash table was added on top of the nvlist code, there were
cases where the nvlist allocation was changed from fnvlist_alloc()
to nvlist_alloc() to avoid expensive NV_UNIQUE_NAME checks. Now
this is no longer necessary. These changes should be reverted to be
consistent with other code. There are some cases where this change
will also reduce the number of iterations.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mark Maybee <mark.maybee@delphix.com>
Closes#11464
There is a race condition in zfs_zrele_async when we are checking if
we would be the one to evict an inode. This can lead to a txg sync
deadlock.
Instead of calling into iput directly, we attempt to perform the atomic
decrement ourselves, unless that would set the i_count value to zero.
In that case, we dispatch a call to iput to run later, to prevent a
deadlock from occurring.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#11527Closes#11530
The runtime of vdev_validate is dominated by the disk accesses in
vdev_label_read_config. Speed it up by validating all vdevs in
parallel using a taskq.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes#11470
This is similar to what we already do in vdev_geom_read_config.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes#11470
metaslab_init is the slowest part of importing a mature pool, and it
must be repeated hundreds of times for each top-level vdev. But its
speed is dominated by a few serialized disk accesses. That can lead to
import times of > 1 hour for pools with many top-level vdevs on spinny
disks.
Speed up the import by using a taskqueue to parallelize vdev_load across
all top-level vdevs.
This also requires adding mutex protection to
metaslab_class_t.mc_historgram. The mc_histogram fields were
unprotected when that code was first written in "Illumos 4976-4984 -
metaslab improvements" (OpenZFS
f3a7f6610f). The lock wasn't added until
3dfb57a35e, though it's unclear exactly
which fields it's supposed to protect. In any case, it wasn't until
vdev_load was parallelized that any code attempted concurrent access to
those fields.
Sponsored by: Axcient
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes#11470
In order for cppcheck to perform a proper analysis it needs to be
aware of how the sources are compiled (source files, include
paths/files, extra defines, etc). All the needed information is
available from the Makefiles and can be leveraged with a generic
cppcheck Makefile target. So let's add one.
Additional minor changes:
* Removing the cppcheck-suppressions.txt file. With cppcheck 2.3
and these changes it appears to no longer be needed. Some inline
suppressions were also removed since they appear not to be
needed. We can add them back if it turns out they're needed
for older versions of cppcheck.
* Added the ax_count_cpus m4 macro to detect at configure time how
many processors are available in order to run multiple cppcheck
jobs. This value is also now used as a replacement for nproc
when executing the kernel interface checks.
* "PHONY =" line moved in to the Rules.am file which is included
at the top of all Makefile.am's. This is just convenient becase
it allows us to use the += syntax to add phony targets.
* One upside of this integration worth mentioning is it now allows
`make cppcheck` to be run in any directory to check that subtree.
* For the moment, cppcheck is not run against the FreeBSD specific
kernel sources. The cppcheck-FreeBSD target will need to be
implemented and testing on FreeBSD to support this.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11508
Identical condition and return expression 'rc', return value is
always 0.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11508
The ASSERT that the passed pointer isn't NULL appears after the
pointer has already been dereferenced. Remove the redundant check.
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11508
When scrubbing, (non-sequential) resilvering, or correcting a checksum
error using RAIDZ parity, ZFS should heal any incorrect RAIDZ parity by
overwriting it. For example, if P disks are silently corrupted (P being
the number of failures tolerated; e.g. RAIDZ2 has P=2), `zpool scrub`
should detect and heal all the bad state on these disks, including
parity. This way if there is a subsequent failure we are fully
protected.
With RAIDZ2 or RAIDZ3, a block can have silent damage to a parity
sector, and also damage (silent or known) to a data sector. In this
case the parity should be healed but it is not.
The problem can be noticed by scrubbing the pool twice. Assuming there
was no damage concurrent with the scrubs, the first scrub should fix all
silent damage, and the second scrub should be "clean" (`zpool status`
should not report checksum errors on any disks). If the bug is
encountered, then the second scrub will repair the silently-damaged
parity that the first scrub failed to repair, and these checksum errors
will be reported after the second scrub. Since the first scrub repaired
all the damaged data, the bug can not be encountered during the second
scrub, so subsequent scrubs (more than two) are not necessary.
The root cause of the problem is some code that was inadvertently added
to `raidz_parity_verify()` by the DRAID changes. The incorrect code
causes the parity healing to be aborted if there is damaged data
(`rc_error != 0`) or the data disk is not present (`!rc_tried`). These
checks are not necessary, because we only call `raidz_parity_verify()`
if we have the correct data (which may have been reconstructed using
parity, and which was verified by the checksum).
This commit fixes the problem by removing the incorrect checks in
`raidz_parity_verify()`.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#11489Closes#11510
Create a common exit point for spa_export_common (a very long
function), which avoids missing steps on failure. This work
is helpful for the planned forced pool export changes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Will Andrews <will@firepipe.net>
Closes#11514
Like any other thread created by thread_create() we need to call
thread_exit() to properly clean it up. In particular, this ensures the
tsd hash for the thread is cleared.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#11512
Fix two minor errors reported by cppcheck:
In module/zfs/abd.c (abd_get_offset_impl), add non-NULL
assertion to prevent NULL dereference warning.
In module/zfs/arc.c (l2arc_write_buffers), change 'try'
variable to 'pass' to avoid C++ reserved word.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Colm Buckley <colm@tuatha.org>
Closes#11507
Follow up for commit 624222a, value asserted <= SPA_OLD_MAXBLOCKSIZE
instead of SPA_MAXBLOCKSIZE as it should be after the previous change.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#11501
Set VIRF_MOUNTPOINT flag on snapshot mountpoint.
Authored-by: Mateusz Guzik <mjg@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11458
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
As part of commit 1c2358c1 the custom uio_prefaultpages() code
was removed in favor of using the generic kernel provided
iov_iter_fault_in_readable() interface. Unfortunately, it
turns out that up until the Linux 4.7 kernel the function would
only ever fault in the first iovec of the iov_iter. The result
being uiomove_iov() may hang waiting for the page.
This commit effectively restores the custom uio_prefaultpages()
pages code for Linux 4.9 and earlier kernels which contain the
troublesome version of iov_iter_fault_in_readable().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#11463Closes#11484
In FreeBSD the struct uio was just a typedef to uio_t. In order to
extend this struct, outside of the definition for the struct uio, the
struct uio has been embedded inside of a uio_t struct.
Also renamed all the uio_* interfaces to be zfs_uio_* to make it clear
this is a ZFS interface.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Brian Atkinson <batkinson@lanl.gov>
Closes#11438
The `abd_get_offset_*()` routines create an abd_t that references
another abd_t, and doesn't allocate any pages/buffers of its own. In
some workloads, these routines may be called frequently, to create many
abd_t's representing small pieces of a single large abd_t. In
particular, the upcoming RAIDZ Expansion project makes heavy use of
these routines.
This commit adds the ability for the caller to allocate and provide the
abd_t struct to a variant of `abd_get_offset_*()`. This eliminates the
cost of allocating the abd_t and performing the accounting associated
with it (`abdstat_struct_size`). The RAIDZ/DRAID code uses this for
the `rc_abd`, which references the zio's abd. The upcoming RAIDZ
Expansion project will leverage this infrastructure to increase
performance of reads post-expansion by around 50%.
Additionally, some of the interfaces around creating and destroying
abd_t's are cleaned up. Most significantly, the distinction between
`abd_put()` and `abd_free()` is eliminated; all types of abd_t's are
now disposed of with `abd_free()`.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #8853Closes#11439
