This allows reads/writes caused by accesses to mmap files to be
accounted correctly in the per-dataset kstats for both Linux and
FreeBSD.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Signed-off-by: Matthias Blankertz <matthias@blankertz.org>
Closes#12994Closes#13044
Raw receiving a snapshot back to the originating dataset is currently
impossible because of user accounting being present in the originating
dataset.
One solution would be resetting user accounting when raw receiving on
the receiving dataset. However, to recalculate it we would have to dirty
all dnodes, which may not be preferable on big datasets.
Instead, we rely on the os_phys flag
OBJSET_FLAG_USERACCOUNTING_COMPLETE to indicate that user accounting is
incomplete when raw receiving. Thus, on the next mount of the receiving
dataset the local mac protecting user accounting is zeroed out.
The flag is then cleared when user accounting of the raw received
snapshot is calculated.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#12981Closes#10523Closes#11221Closes#11294Closes#12594
Issue #11300
When using the two argument version of submit_bio() in kernel's prior
to 4.8 the first argument should be specified. It's used by block
dump to report the bio direction.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Finix Yan <yancw@info2soft.com>
Closes#13006
Linux 5.17 sees a rename from complete_and_exit()
to kthread complete_and_exit()
Upstream commit cead18552660702a4a46f58e65188fe5f36e9dfe
("exit: Rename complete_and_exit to kthread_complete_and_exit")
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12989
For us, I think it's always just FALLOC_FL_PUNCH_HOLE with a fake
mustache on.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12975
add_disk went from void to must-check int return.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12975
First open locking changes were correctly applied to zvol_geom_open but
incorrectly applied to zvol_cdev_open, causing spa_namespace_lock to be
held indefinitely.
Make the first open locking in zvol_cdev_open match zvol_geom_open.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#13016
These are the changes for FreeBSD corresponding to the changes made for
Linux in #12863, see that PR for details.
Changes from #12863 are applied for zvol_geom_open and zvol_cdev_open
on FreeBSD. This also adds a check for the zvol dying which we had
in zvol_geom_open but was missing in zvol_cdev_open. The check causes
the open to fail early with ENXIO when we are in the middle of changing
volmode.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#12934
Fix from https://github.com/openzfs/zfs/pull/12844#discussion_r774179413
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12905
sc.nr_to_scan is an input to super_cache_clean (via
shrinker->scan_objects), used to set the number of objects to scan
in the various caches. However super_cache_scan also modifies
sc.nr_to_scan, so when used in a loop we need to reset
sc.nr_to_scan back to our desired nr_to_scan for the next
iteration.
Issue discovered and solution suggested by
Tenzin Lhakhang @tlhakhan.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Issue #12433Closes#12908
When performing I/O on FreeBSD using a file based vdev ensure all
errors encountered when reading/writing are propagated through the
zio pipeline.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12904
When restructuring the zvol_open() logic for the Linux 5.13 kernel
a lock inversion was accidentally introduced. In the updated code
the spa_namespace_lock is now taken before the zv_suspend_lock
allowing the following scenario to occur:
down_read <=== waiting for zv_suspend_lock
zvol_open <=== holds spa_namespace_lock
__blkdev_get
blkdev_get_by_dev
blkdev_open
...
mutex_lock <== waiting for spa_namespace_lock
spa_open_common
spa_open
dsl_pool_hold
dmu_objset_hold_flags
dmu_objset_hold
dsl_prop_get
dsl_prop_get_integer
zvol_create_minor
dmu_recv_end
zfs_ioc_recv_impl <=== holds zv_suspend_lock via zvol_suspend()
zfs_ioc_recv
...
This commit resolves the issue by moving the acquisition of the
spa_namespace_lock back to after the zv_suspend_lock which restores
the original ordering.
Additionally, as part of this change the error exit paths were
simplified where possible.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12863
A recent commit to FreeBSD changed the type of
vop_readdir_args.a_cookies to a uint64_t**. There is no functional
impact to ZFS because ZFS only uses 32-bit cookies, which will be
zero-extended to 64-bits by the existing code.
b214fcceac
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Alan Somers <asomers@gmail.com>
Closes#12874
va_seq was actually a thin veil over va_gen, so z_gen is a more
appropriate value than z_seq to populate the field with.
Drop the unnecessary compat obfuscation and provide the correct
file generation number.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <freqlabs@freebsd.org>
Closes#12851
- To avoid a use-after-free, zfsvfs->z_log needs to be loaded after the
teardown lock is acquired with ZFS_ENTER().
- Avoid leaking vnode locks in zfs_rename_relock() and zfs_rename_()
when the ZFS_ENTER() macros forces an early return.
Refactor the rename implementation so that ZFS_ENTER() can be used
safely. As a bonus, this lets us use the ZFS_VERIFY_ZP() macro instead
of open-coding its implementation.
Reported-by: Peter Holm <pho@FreeBSD.org>
Tested-by: Peter Holm <pho@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Sponsored-by: The FreeBSD Foundation
Closes#12717
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes#12748
We have to hold the teardown lock while dereferencing zfsvfs->z_os and,
I believe, when committing to the ZIL.
Note that jumping to the "out" label, "error" is always non-zero.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#12704
The objset object is reallocated during certain dataset operations, such
as rollbacks, so the objset pointer must be loaded after acquiring the
teardown lock.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#12704
The definition of struct blkcg_gq was moved into blk-cgroup.h, which is
a header that's been in Linux since 2015. This is used by
vdev_blkg_tryget() in module/os/linux/zfs/vdev_disk.c. Since the kernel
for CentOS 7 and similar-generation releases doesn't have this header,
its inclusion is guarded by a configure test.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
This change adds a confiugre check to determine if bio_set_dev is a
helper macro or not. If not, then the attempt to override its internal
call to bio_associate_blkg(), with a macro definition to our own
version, is no longer possible, as the compiler won't use it when
compiling the new inline function replacement implemented in the header.
This change also creates a new vdev_bio_set_dev() function that performs
the same work, and also performs the work implemented in
vdev_bio_associate_blkg(), as it is the only thing calling that function
in our code. Our custom vdev_bio_associate_blkg() is now only compiled
if the bio_set_dev() is a macro in the Linux headers.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
The iov_iter->type member was renamed iov_iter->iter_type. However,
while looking into this, realized that in 2018 a iov_iter_type(*iov)
accessor function was introduced. So if that is present, use it,
otherwise fall back to trying the existing behavior of directly
accessing type from iov_iter.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
The return type for the submit_bio member of struct
block_device_operations was changed to no longer return a value.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12819
Due to a possible lock inversion the zvol open call path on Linux
needs to be able to retry in the case where the spa_namespace_lock
cannot be acquired.
For Linux 5.12 an older kernel this was accomplished by returning
-ERESTARTSYS from zvol_open() to request that blkdev_get() drop
the bdev->bd_mutex lock, reaquire it, then call the open callback
again. However, as of the 5.13 kernel this behavior was removed.
Therefore, for 5.12 and older kernels we preserved the existing
retry logic, but for 5.13 and newer kernels we retry internally in
zvol_open(). This should always succeed except in the case where
a pool's vdev are layed on zvols, in which case it may fail. To
handle this case vdev_disk_open() has been updated to retry when
opening a device when -ERESTARTSYS is returned.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #12301Closes#12759
Instead, linux/pagemap.h offers a number of folio-specific functions to
be called instead. In this case, module/os/linux/zfs/zfs_vnops_os.c
wants to call wait_on_page_bit(pp, PG_writeback). This gets replaced
with folio_wait_bit(folio_page(pp), PG_writeback). This change modifies
the code to conditionally compile that if configure identifies th
presence of the folio_wait_bit() function.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12800
The submit_bio() prototype has changed again. The version is 5.16
still only expects a single argument but the return type has changed
to void. Since we never used the returned value before update the
configure check to detect both single arg versions.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12725
As of the Linux 5.9 kernel a fallthrough macro has been added which
should be used to anotate all intentional fallthrough paths. Once
all of the kernel code paths have been updated to use fallthrough
the -Wimplicit-fallthrough option will because the default. To
avoid warnings in the OpenZFS code base when this happens apply
the fallthrough macro.
Additional reading: https://lwn.net/Articles/794944/
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12441
Kernel commits
332f606b32b6 ovl: enable RCU'd ->get_acl()
0cad6246621b vfs: add rcu argument to ->get_acl() callback
Added compatibility code to detect the new ->get_acl() interface
and correctly handle the case where the new rcu argument is set.
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12548
We attempt to remove an existing SA xattr when setting a dir xattr, but
this only makes sense if the znode has been upgraded to the SA format.
Otherwise, we will hit an assert in zfs_sa_get_xattr.
Make sure this is an SA znode before attempting to remove the SA xattr.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#12514
Linux 4.11 added a new statx system call that allows us to expose crtime
as btime. We do this by caching crtime in the znode to match how atime,
ctime and mtime are cached in the inode.
statx also introduced a new way of reporting whether the immutable,
append and nodump bits have been set. It adds support for reporting
compression and encryption, but the semantics on other filesystems is
not just to report compression/encryption, but to allow it to be turned
on/off at the file level. We do not support that.
We could implement semantics where we refuse to allow user modification
of the bit, but we would need to do a dnode_hold() in zfs_znode_alloc()
to find out encryption/compression information. That would introduce
locking that will have a minor (although unmeasured) performance cost.
It also would be inferior to zdb, which reports far more detailed
information. We therefore omit reporting of encryption/compression
through statx in favor of recommending that users interested in such
information use zdb.
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes#8507
When a header is allocated for full overwrite it is a waste of time
to allocate b_pabd/b_rabd for it, since arc_write() will free them
without ever being touched. If it is a read or a partial overwrite
then arc_read() and arc_hdr_decrypt() allocate them explicitly.
Reduced memory allocation in user threads also reduces ARC eviction
throttling there, proportionally increasing it in ZIO threads, that
is not good. To minimize or even avoid it introduce ARC allocation
reserve, allowing certain arc_get_data_abd() callers to allocate a
bit longer in situations where user threads will already throttle.
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12398
Before OpenZFS 2.0, trying to set the FreeBSD sysctl vfs.zfs.arc_max
to a disallowed value would return an error.
Since the switch, it instead only generates WARN_IF_TUNING_IGNORED
Keep the ability to set the sysctl's specifically to 0, even though
that is less than the minimum, because some tests depend on this.
Also lost, was the ability to set vfs.zfs.arc_max to a value less
than the default vfs.zfs.arc_min at boot time. Restore this as well.
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#12161
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Martin Matuska <mm@FreeBSD.org>
Co-authored-by: Konstantin Belousov <kib@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
External-issue: https://reviews.freebsd.org/D31207Closes#12442
The /proc/diskstats accounting needs to be explicitly enabled
for block devices which do not use multi-queue.
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12440Closes#12066
CpaDcGeneratefooter function that obtain the checksum code
does not support the CPA_DC_STATELESS mode. So we get the
adler32 chencksum of the end of the zlib from dc_results.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chengfei Zhu <chengfeix.zhu@intel.com>
Signed-off-by: hedong.zhang <h_d_zhang@163.com>
Closes#12343
We have a tunable which permits one to disable the use of unmapped I/O
for the buffer cache. Respect it in ZFS as well. This is useful for
KMSAN, which cannot easily maintain shadow state for unmapped pages.
No functional change intended, as unmapped I/O is permitted by default
and there's no real reason to disable it in practice except for
debugging.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#12446
Kernel 5.14 introduced a change where set_page_dirty of
struct address_space_operations is no longer implicitly set to
__set_page_dirty_buffers(), which ended up resulting in a NULL
pointer deref in the kernel when it is attempted to be called.
This change sets .set_page_dirty in the structure to
__set_page_dirty_nobuffers(), which was introduced with the
related patch set. The breaking change was introduce in commit
0af573780b0b13fceb7fabd49dc1b073cee9a507 to torvalds/linux.git.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#12427
In Linux 5.14, blk_alloc_queue is no longer exported, and its usage
has been superseded by blk_alloc_disk, which returns a gendisk struct
from which we can still retrieve the struct request_queue* that is
needed in the one place where it is used. This also replaces the call
to alloc_disk(minors), and minors is now set via struct member
assignment.
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Coleman Kane <ckane@colemankane.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12362Closes#12409
Since errors returned by zvol_create_minor_impl() are ignored by the
common code, it is more convenient to ignore make_dev_s() errors there.
It allows, for example, to get device created for the zvol after later
rename instead of having it further stuck in half-created state.
zvol_rename_minor() already ignores those errors.
While there, switch from MAXPHYS to maxphys in FreeBSD 13+.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12375
* zio: avoid callback typecasting
* zil: avoid zil_itxg_clean() callback typecasting
* zpl: decouple zpl_readpage() into two separate callbacks
* nvpair: explicitly declare callbacks for xdr_array()
* linux/zfs_nvops: don't use external iput() as a callback
* zcp_synctask: don't use fnvlist_free() as a callback
* zvol: don't use ops->zv_free() as a callback for taskq_dispatch()
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Closes#12260
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12378
arc_evict_hdr() returns number of evicted bytes in scope of specific
state. For ghost states it does not mean the amount of really freed
memory, but the logical buffer size. It is correct for the eviction
process, but not for waking up threads waiting for ARC size reduction,
as added in "Revise ARC shrinker algorithm" commit, causing premature
wakeups while ARC is still overflowed, allowing even bigger overflow,
plus processing overhead when next allocation will also get blocked,
probably also for too short time.
To fix that make arc_evict_hdr() also return the amount of really
freed memory, which for the ghost states is only the header, and use
it to update arc_evict_count instead. Originally I was thinking to
not return it at all, since arc_get_data_impl() does not account for
the headers, but decided that some slow allocation progress is better
than long waits, reaching on my tests up to 100ms.
To reduce negative latency effects of long time periods when reclaim
thread can free little real memory, start reclamation process earlier,
before we actually reached the overflow threshold, when we have to
throttle new allocations. We can also do it without taking global
arc_evict_lock, reducing the contention.
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12279
Callers of zfs_file_get and zfs_file_put can corrupt the reference
counts for the file structure resulting in a panic or a soft lockup.
When zfs send/recv runs, it will add a reference count to the
open file, and begin to send or recv the stream. If the file descriptor
is closed, then when dmu_recv_stream() or dmu_send() return we will
call zfs_file_put to remove the reference we placed on the file
structure. Unfortunately, because zfs_file_put() uses the file
descriptor to lookup the file structure, it may end up finding that
the file descriptor table no longer contains the file struct, thus
leaking the file structure. Or it might end up finding a file
descriptor for a different file and blindly updating its reference
counts. Other failure modes probably exists.
This change reworks the zfs_file_[get|put] interface to not rely
on the file descriptor but instead pass the zfs_file_t pointer around.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Co-authored-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-issue: DLPX-76119
Closes#12299
Many FreeBSD disk drivers support "unmapped" I/O mode, when data
buffer represented not with a virtually contiguous KVA-mapped address
range, but with a list of physical memory pages. Originally it was
designed to do I/O from buffers without KVA mapping (unmapped). But
moving virtual addresses out of equation allows us to operate even
non-contiguous data buffers with one condition: all buffer discon-
tinuities must be aligned to memory page borders.
Doing I/O to capable GEOM device this patch traverses through non-
linear ABD buffers, validating the chunks borders. If the condition
is met, it supplies GEOM with the list of original physical memory
pages instead of copying the data into temporary contiguous buffer.
On capable hardware on pools with ashift=12 and default ABD chunk of
4KB it should handle all the I/O without additional memory copying.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12320