Commit Graph

8995 Commits

Author SHA1 Message Date
Alexander Motin
602b5dca7b Fix read errors race after block cloning
Investigating read errors triggering panic fixed in #16042 I've
found that we have a race in a sync process between the moment
dirty record for cloned block is removed and the moment dbuf is
destroyed.  If dmu_buf_hold_array_by_dnode() take a hold on a
cloned dbuf before it is synced/destroyed, then dbuf_read_impl()
may see it still in DB_NOFILL state, but without the dirty record.
Such case is not an error, but equivalent to DB_UNCACHED, since
the dbuf block pointer is already updated by dbuf_write_ready().
Unfortunately it is impossible to safely change the dbuf state
to DB_UNCACHED there, since there may already be another cloning
in progress, that dropped dbuf lock before creating a new dirty
record, protected only by the range lock.

Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Robert Evans <evansr@google.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #16052
2024-04-19 10:13:38 -07:00
Alexander Motin
d5fb6abd36 Improve dbuf_read() error reporting
Previous code reported non-ZIO errors only via return value, but
not via parent ZIO.  It could cause NULL-dereference panics due
to dmu_buf_hold_array_by_dnode() ignoring the return value,
relying solely on parent ZIO status.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reported by:	Ameer Hamza <ahamza@ixsystems.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #16042
2024-04-19 10:13:38 -07:00
Alexander Motin
39993c3dfe BRT: Check pool clone stats in more tests
This should allow to catch some leaks, if those happen.

While there fix some cosmetic issues.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #16007
2024-04-19 10:13:38 -07:00
Alexander Motin
e3c1c9153f BRT: Fix tests to work on non-empty pools
It should not normally happen, but if it does, better to not fail
everything for no good reason, or it may be hard to debug.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #16007
2024-04-19 10:13:38 -07:00
Alexander Motin
2ea370a4e3 BRT: Fix holes cloning.
- When reading L0 block pointers handle buffers without ones and
without dirty records as a holes.  Those appear when dnode size
was increased, but the end was never written, so there are no new
indirection levels to store the pointers.  It makes no sense to
return EAGAIN here, since sync won't create new indirection levels
until there will be actual writes.
 - When cloning blocks set destination hole logical birth time
to the current TXG.  Otherwise if we are cloning over existing
data, newly created holes may not be properly replicated later.
Use BP_SET_BIRTH() when possible to not replicate its logic.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #15994
Closes #16007
2024-04-19 10:13:38 -07:00
Alexander Motin
3e91a9c525 BRT: Skip getting length in brt_entry_lookup()
Unlike DDT, where ZAP values may have different lengths due to
compression, all BRT entries are identical 8-byte counters.  It
does not make sense to first fetch the length only to assert it.
zap_lookup_uint64() is specifically designed to work with counters
of different size and should return error if something odd found.
Calling it straight allows to save some measurable CPU time.

Reviewed-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15950
2024-04-19 10:13:38 -07:00
Alexander Motin
c94f730078 BRT: Make BRT block sizes configurable
Similar to DDT make BRT data and indirect block sizes configurable
via module parameters.  I am not sure what would be the best yet,
but similar to DDT 4KB blocks kill all chances of compression on
vdev with ashift=12 or more, that on my tests reaches 3x.

While here, fix documentation for respective DDT parameters.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15967
2024-04-19 10:13:38 -07:00
Alexander Motin
457e62d7ca BRT: Relax brt_pending_apply() locking
Since brt_pending_apply() is running in syncing context, no other
brt_pending_tree accesses are possible for the TXG.  We don't need
to acquire brt_pending_lock here.

Reviewed-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15955
2024-04-19 10:13:38 -07:00
Alexander Motin
19bf54b764 ZAP: Massively switch to _by_dnode() interfaces
Before this change ZAP called dnode_hold() for almost every block
access, that was clearly visible in profiler under heavy load, such
as BRT.  This patch makes it always hold the dnode reference between
zap_lockdir() and zap_unlockdir().  It allows to avoid most of dnode
operations between those.  It also adds several new _by_dnode() APIs
to ZAP and uses them in BRT code.  Also adds dmu_prefetch_by_dnode()
variant and uses it in the ZAP code.

After this there remains only one call to dmu_buf_dnode_enter(),
which seems to be unneeded.  So remove the call and the functions.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15951
2024-04-19 10:13:38 -07:00
Alexander Motin
fdd8c0aea1 BRT: Skip duplicate BRT prefetches
If there is a pending entry for this block, then we've already
issued BRT prefetch for it within this TXG, so don't do it again.
BRT vdev lookup and following zap_prefetch_uint64() call can be
pretty expensive and should be avoided when not necessary.

Reviewed-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15941
2024-04-19 10:13:38 -07:00
Alexander Motin
dced953b62 ZAP: Some cleanups/micro-optimizations
- Remove custom zap_memset(), use regular memset().
- Use PANIC() instead of opaque cmn_err(CE_PANIC).
- Provide entry parameter to zap_leaf_rehash_entry().
- Reduce branching in zap_leaf_array_create() inner loop.
- Remove signedness where it should not be.

Should be no function changes.

Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15976
2024-04-19 10:13:38 -07:00
Alexander Motin
f7c1db6366 BRT: Change brt_pending_tree sorting order
It does not look important how exactly brt_pending_tree is sorted.
When cloning large file, it is quite likely that all of its blocks
have identical physical birth times, so comparing them first does
not provide useful entropy, while accesses additional cache line.
In most cases combination of vdev and offset provides unique result
and physical birth time comparison is not even needed.  Meanwhile,
when traversing the tree inside brt_pending_apply(), it can be
beneficial for dbuf cache and CPU cache hits to group processing
by vdev and so by the per-VDEV BRT ZAPs.

Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15954
2024-04-19 10:13:38 -07:00
Alexander Motin
fa5de0c5cd Update resume token at object receive.
Before this change resume token was updated only on data receive.
Usually it is enough to resume replication without much overlap.
But we've got a report of a curios case, where replication source
was traversed with recursive grep, which through enabled atime
modified every object without modifying any data.  It produced
several gigabytes of replication traffic without a single data
write and so without a single resume point.

While the resume token was not designed to resume from an object,
I've found that the send implementation always sends object before
any data. So by requesting resume from offset 0 we are effectively
resuming from the object, followed (or not) by the data at offset
0, just as we need it.

Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15927
2024-04-19 10:13:38 -07:00
Alexander Motin
793a2cff2a Linux: Cleanup taskq threads spawn/exit
This changes taskq_thread_should_stop() to limit maximum exit rate
for idle threads to one per 5 seconds.  I believe the previous one
was broken, not allowing any thread exits for tasks arriving more
than one at a time and so completing while others are running.

Also while there:
 - Remove taskq_thread_spawn() calls on task allocation errors.
 - Remove extra taskq_thread_should_stop() call.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15873
2024-04-19 10:13:38 -07:00
Alexander Motin
fdd97e0093 Refactor dmu_prefetch().
- Split dmu_prefetch_dnode() from dmu_prefetch() into a separate
function.  It is quite inconvenient to read the code where len = 0
means dnode prefetch instead indirect/data prefetch.  One function
doing both has no benefits, since the code paths are independent.
 - Improve dmu_prefetch() handling of long block ranges.  Instead
of limiting L0 data length to prefetch for to dmu_prefetch_max,
make dmu_prefetch_max limit the actual amount of prefetch at the
specified level, and, if there is more, prefetch all the rest at
higher indirection level.  It should improve random access times
within the prefetched range of any length, reducing importance of
specific dmu_prefetch_max value.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15076
2024-04-19 10:13:38 -07:00
Alexander Motin
3b8817db96 ZIL: Update Linux tracing after #15635
While picking parts from #14909 I've missed Linux tracing specific
ones, that went unnoticed in default configurations, but breaks the
build in some.

Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15730
2024-04-19 10:13:38 -07:00
Alexander Motin
25ea8ce94b ZIL: Improve next log block size prediction
Track history in context of bursts, not individual log blocks. It
allows to not blow away all the history by single large burst of
many block, and same time allows optimizations covering multiple
blocks in a burst and even predicted following burst.  For each
burst account its optimal block size and minimal first block size.
Use that statistics from the last 8 bursts to predict first block
size of the next burst.

Remove predefined set of block sizes. Allocate any size we see fit,
multiple of 4KB, as required by ZIL now.  With compression enabled
by default, ZFS already writes pretty random block sizes, so this
should not surprise space allocator any more.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15635
2024-04-19 10:13:38 -07:00
Alexander Motin
8b1a132de7 ZIO: Optimize zio_flush()
- Generalize vdev_nowritecache handling by traversing through the
VDEV tree and skipping children ZIOs where not supported.
 - Remove intermediate zio_null() in case of several VDEV children.
 - Remove children handling from zio_ioctl().  There are no other
use cases for this code beside DKIOCFLUSHWRITECACHED, and would there
be, I doubt they would so straightforward apply to all VDEV children.

Comparing to removed previous optimization this should improve cases
of redundant ZILs/SLOGs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15515
2024-04-19 10:13:38 -07:00
Alexander Motin
7ea8331009 ZIL: Detect single-threaded workloads
... by checking that previous block is fully written and flushed.
It allows to skip commit delays since we can give up on aggregation
in that case.  This removes zil_min_commit_timeout parameter, since
for single-threaded workloads it is not needed at all, while on very
fast devices even some multi-threaded workloads may get detected as
single-threaded and still bypass the wait.  To give multi-threaded
workloads more aggregation chances increase zfs_commit_timeout_pct
from 5 to 10%, as they should suffer less from additional latency.

Also single-threaded workloads detection allows in perspective better
prediction of the next block size.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15381
2024-04-19 10:13:38 -07:00
Rob N
3c5f354a8c zvol_os: fix compile with blk-mq on Linux 4.x
99741bde5 accesses a cached blk-mq hardware context through the mq_hctx
field of struct request. However, this field did not exist until 5.0.
Before that, the private function blk_mq_map_queue() was used to dig it
out of broader queue context. This commit detects this situation, and
handles it with a poor-man's simulation of that function.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16069
2024-04-17 10:10:24 -07:00
Rob N
5c0fe099ec zvol_os: fix build on Linux <3.13
99741bde5 introduced zvol_num_taskqs, but put it behind the HAVE_BLK_MQ
define, preventing builds on versions of Linux that don't have it
(<3.13, incl EL7).

Nothing about it seems dependent on blk-mq, so this just moves it out
from behind that define and so fixes the build.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Ameer Hamza <ahamza@ixsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16062
2024-04-17 10:10:24 -07:00
Ameer Hamza
5fc134ff2f zvol: use multiple taskq
Currently, zvol uses a single taskq, resulting in throughput bottleneck
under heavy load due to lock contention on the single taskq. This patch
addresses the performance bottleneck under heavy load conditions by
utilizing multiple taskqs, thus mitigating lock contention. The number
of taskqs scale dynamically based on the available CPUs in the system,
as illustrated below:

                taskq   total
cpus    taskqs  threads threads
------- ------- ------- -------
1       1       32       32
2       1       32       32
4       1       32       32
8       2       16       32
16      3       11       33
32      5       7        35
64      8       8        64
128     11      12       132
256     16      16       256

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #15992
2024-04-17 10:10:24 -07:00
Rob Norris
7ad2616d37 vdev_disk: fix alignment check when buffer has non-zero starting offset
If a linear buffer spans multiple pages, and the first page has a
non-zero starting offset, the checker would not include the offset, and
so would think there was an alignment gap at the end of the first page,
rather than at the start.

That is, for a 16K buffer spread across five pages with an initial 512B
offset:

    [.XXXXXXX][XXXXXXXX][XXXXXXXX][XXXXXXXX][XXXXXXX.]

It would be interpreted as:

    [XXXXXXX.][XXXXXXXX]...

And be rejected as misaligned.

Since it's already a linear ABD, the "linearising" copy would just reuse
the buffer as-is, and the second check would failing, tripping the
VERIFY in vdev_disk_io_rw().

This commit fixes all this by including the offset in the check for
end-of-page alignment.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
(cherry picked from commit 1bf649cb0a)
2024-04-12 08:53:48 -07:00
Rob N
d0d9dccc61 vdev_disk: ensure trim errors are returned immediately
After 08fd5ccc3, the discard issuing code was organised such that if
requesting an async discard or secure erase failed before the IO was
issued (that is, calling __blkdev_issue_discard() returned an error),
the failed zio would never be executed, resulting in txg_sync hanging
forever waiting for IO to finish.

This commit fixes that by immediately executing a failed zio on error.
To handle the successful synchronous op case, we fake an async op by,
when not using an asynchronous submission method, queuing the successful
result zio as part of the discard handler.

Since it was hard to understand the differences between discard and
secure erase, and sync and async, across different kernel versions, I've
commented and reorganised the code a bit to try and make everything more
contained and linear.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
(cherry picked from commit ba9f587a77)
2024-04-11 12:25:40 -07:00
Rob Norris
28520cad25 vdev_disk: don't touch vbio after its handed off to the kernel
After IO is unplugged, it may complete immediately and vbio_completion
be called on interrupt context. That may interrupt or deschedule our
task. If its the last bio, the vbio will be freed. Then, we get
rescheduled, and try to write to freed memory through vbio->.

This patch just removes the the cleanup, and the corresponding assert.
These were leftovers from a previous iteration of vbio_submit() and were
always "belt and suspenders" ops anyway, never strictly required.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc
Reported-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
(cherry picked from commit 917ff75e95)
2024-04-08 10:13:55 -07:00
Robert Evans
deb7a84231 Fix corruption caused by mmap flushing problems
1) Make mmap flushes synchronous. Linux may skip flushing dirty pages
   already in writeback unless data-integrity sync is requested.

2) Change zfs_putpage to use TXG_WAIT. Otherwise dirty pages may be
   skipped due to DMU pushing back on TX assign.

3) Add missing mmap flush when doing block cloning.

4) While here, pass errors from putpage to writepage/writepages.

This change fixes corruption edge cases, but unfortunately adds
synchronous ZIL flushes for dirty mmap pages to llseek and bclone
operations. It may be possible to avoid these sync writes later
but would need more tricky refactoring of the writeback code.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Robert Evans <evansr@google.com>
Closes #15933 
Closes #16019
2024-03-29 17:10:04 -07:00
Rob Norris
eebf00bee9 vdev_disk: default to classic submission for 2.2.x
We don't want to change to brand-new code in the middle of a stable
series, but we want it available to test for people running into page
splitting issues.

This commits make zfs_vdev_disk_classic=1 the default, and updates the
documentation to better explain what's going on.

Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
2024-03-28 13:29:46 -07:00
Rob Norris
d0b3be763f abd_iter_page: don't use compound heads on Linux <4.5
Before 4.5 (specifically, torvalds/linux@ddc58f2), head and tail pages
in a compound page were refcounted separately. This means that using the
head page without taking a reference to it could see it cleaned up later
before we're finished with it. Specifically, bio_add_page() would take a
reference, and drop its reference after the bio completion callback
returns.

If the zio is executed immediately from the completion callback, this is
usually ok, as any data is referenced through the tail page referenced
by the ABD, and so becomes "live" that way. If there's a delay in zio
execution (high load, error injection), then the head page can be freed,
along with any dirty flags or other indicators that the underlying
memory is used. Later, when the zio completes and that memory is
accessed, its either unmapped and an unhandled fault takes down the
entire system, or it is mapped and we end up messing around in someone
else's memory. Both of these are very bad.

The solution on these older kernels is to take a reference to the head
page when we use it, and release it when we're done. There's not really
a sensible way under our current structure to do this; the "best" would
be to keep a list of head page references in the ABD, and release them
when the ABD is freed.

Since this additional overhead is totally unnecessary on 4.5+, where
head and tail pages share refcounts, I've opted to simply not use the
compound head in ABD page iteration there. This is theoretically less
efficient (though cleaning up head page references would add overhead),
but its safe, and we still get the other benefits of not mapping pages
before adding them to a bio and not mis-splitting pages.

There doesn't appear to be an obvious symbol name or config option we
can match on to discover this behaviour in configure (and the mm/page
APIs have changed a lot since then anyway), so I've gone with a simple
version check.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit c6be6ce175)
2024-03-28 13:29:46 -07:00
Rob Norris
cb599d27ed vdev_disk: use bio_chain() to submit multiple BIOs
Simplifies our code a lot, so we don't have to wait for each and
reassemble them.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit 72fd834c47)
2024-03-28 13:29:46 -07:00
Rob Norris
af3a5bb40d vdev_disk: add module parameter to select BIO submission method
This makes the submission method selectable at module load time via the
`zfs_vdev_disk_classic` parameter, allowing this change to be backported
to 2.2 safely, and disabled in favour of the "classic" submission method
if new problems come up.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit df2169d141)
2024-03-28 13:29:46 -07:00
Rob Norris
51c2bd0def vdev_disk: rewrite BIO filling machinery to avoid split pages
This commit tackles a number of issues in the way BIOs (`struct bio`)
are constructed for submission to the Linux block layer.

The kernel has a hard upper limit on the number of pages/segments that
can be added to a BIO, as well as a separate limit for each device
(related to its queue depth and other scheduling characteristics).

ZFS counts the number of memory pages in the request ABD
(`abd_nr_pages_off()`, and then uses that as the number of segments to
put into the BIO, up to the hard upper limit. If it requires more than
the limit, it will create multiple BIOs.

Leaving aside the fact that page count method is wrong (see below), not
limiting to the device segment max means that the device driver will
need to split the BIO in half. This is alone is not necessarily a
problem, but it interacts with another issue to cause a much larger
problem.

The kernel function to add a segment to a BIO (`bio_add_page()`) takes a
`struct page` pointer, and offset+len within it. `struct page` can
represent a run of contiguous memory pages (known as a "compound page").
In can be of arbitrary length.

The ZFS functions that count ABD pages and load them into the BIO
(`abd_nr_pages_off()`, `bio_map()` and `abd_bio_map_off()`) will never
consider a page to be more than `PAGE_SIZE` (4K), even if the `struct
page` is for multiple pages. In this case, it will load the same `struct
page` into the BIO multiple times, with the offset adjusted each time.

With a sufficiently large ABD, this can easily lead to the BIO being
entirely filled much earlier than it could have been. This is also
further contributes to the problem caused by the incorrect segment limit
calculation, as its much easier to go past the device limit, and so
require a split.

Again, this is not a problem on its own.

The logic for "never submit more than `PAGE_SIZE`" is actually a little
more subtle. It will actually never submit a buffer that crosses a 4K
page boundary.

In practice, this is fine, as most ABDs are scattered, that is a list of
complete 4K pages, and so are loaded in as such.

Linear ABDs are typically allocated from slabs, and for small sizes they
are frequently not aligned to page boundaries. For example, a 12K
allocation can span four pages, eg:

     -- 4K -- -- 4K -- -- 4K -- -- 4K --
    |        |        |        |        |
          :## ######## ######## ######:    [1K, 4K, 4K, 3K]

Such an allocation would be loaded into a BIO as you see:

    [1K, 4K, 4K, 3K]

This tends not to be a problem in practice, because even if the BIO were
filled and needed to be split, each half would still have either a start
or end aligned to the logical block size of the device (assuming 4K at
least).

---

In ideal circumstances, these shortcomings don't cause any particular
problems. Its when they start to interact with other ZFS features that
things get interesting.

Aggregation will create a "gang" ABD, which is simply a list of other
ABDs. Iterating over a gang ABD is just iterating over each ABD within
it in turn.

Because the segments are simply loaded in order, we can end up with
uneven segments either side of the "gap" between the two ABDs. For
example, two 12K ABDs might be aggregated and then loaded as:

    [1K, 4K, 4K, 3K, 2K, 4K, 4K, 2K]

Should a split occur, each individual BIO can end up either having an
start or end offset that is not aligned to the logical block size, which
some drivers (eg SCSI) will reject. However, this tends not to happen
because the default aggregation limit usually keeps the BIO small enough
to not require more than one split, and most pages are actually full 4K
pages, so hitting an uneven gap is very rare anyway.

If the pool is under particular memory pressure, then an IO can be
broken down into a "gang block", a 512-byte block composed of a header
and up to three block pointers. Each points to a fragment of the
original write, or in turn, another gang block, breaking the original
data up over and over until space can be found in the pool for each of
them.

Each gang header is a separate 512-byte memory allocation from a slab,
that needs to be written down to disk. When the gang header is added to
the BIO, its a single 512-byte segment.

Pulling all this together, consider a large aggregated write of gang
blocks. This results a BIO containing lots of 512-byte segments. Given
our tendency to overfill the BIO, a split is likely, and most possible
split points will yield a pair of BIOs that are misaligned. Drivers that
care, like the SCSI driver, will reject them.

---

This commit is a substantial refactor and rewrite of much of `vdev_disk`
to sort all this out.

`vdev_bio_max_segs()` now returns the ideal maximum size for the device,
if available. There's also a tuneable `zfs_vdev_disk_max_segs` to
override this, to assist with testing.

We scan the ABD up front to count the number of pages within it, and to
confirm that if we submitted all those pages to one or more BIOs, it
could be split at any point with creating a misaligned BIO.  If the
pages in the BIO are not usable (as in any of the above situations), the
ABD is linearised, and then checked again. This is the same technique
used in `vdev_geom` on FreeBSD, adjusted for Linux's variable page size
and allocator quirks.

`vbio_t` is a cleanup and enhancement of the old `dio_request_t`. The
idea is simply that it can hold all the state needed to create, submit
and return multiple BIOs, including all the refcounts, the ABD copy if
it was needed, and so on. Apart from what I hope is a clearer interface,
the major difference is that because we know how many BIOs we'll need up
front, we don't need the old overflow logic that would grow the BIO
array, throw away all the old work and restart. We can get it right from
the start.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit 06a196020e)
2024-03-28 13:29:46 -07:00
Rob Norris
03ff875e09 vdev_disk: make read/write IO function configurable
This is just setting up for the next couple of commits, which will add a
new IO function and a parameter to select it.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit c4a13ba483)
2024-03-28 13:29:46 -07:00
Rob Norris
13b5348848 vdev_disk: reorganise vdev_disk_io_start
Light reshuffle to make it a bit more linear to read and get rid of a
bunch of args that aren't needed in all cases.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit 867178ae1d)
2024-03-28 13:29:46 -07:00
Rob Norris
4820185031 vdev_disk: rename existing functions to vdev_classic_*
This is just renaming the existing functions we're about to replace and
grouping them together to make the next commits easier to follow.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit f3b85d706b)
2024-03-28 13:29:46 -07:00
Rob Norris
52a2af6fd1 abd: add page iterator
The regular ABD iterators yield data buffers, so they have to map and
unmap pages into kernel memory. If the caller only wants to count
chunks, or can use page pointers directly, then the map/unmap is just
unnecessary overhead.

This adds adb_iterate_page_func, which yields unmapped struct page
instead.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit 390b448726)
2024-03-28 13:29:46 -07:00
Rob Norris
220bb7341e linux 5.4 compat: page_size()
Before 5.4 we have to do a little math.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588
(cherry picked from commit df04efe321)
2024-03-28 13:29:46 -07:00
Rob N
58211157bf Linux 6.8 compat: use splice_copy_file_range() for fallback
Linux 6.8 removes generic_copy_file_range(), which had been reduced to a
simple wrapper around splice_copy_file_range(). Detect that function
directly and use it if generic_ is not available.

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #15930
Closes #15931
(cherry picked from commit ef08a4d406)
2024-03-21 09:35:17 -07:00
Tony Hutter
c883088df8 Tag zfs-2.2.3
META file and changelog updated.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
2024-02-21 09:26:51 -08:00
Alexander Motin
c0c4866f8a dmu: Allow buffer fills to fail
When ZFS overwrites a whole block, it does not bother to read the
old content from disk. It is a good optimization, but if the buffer
fill fails due to page fault or something else, the buffer ends up
corrupted, neither keeping old content, nor getting the new one.

On FreeBSD this is additionally complicated by page faults being
blocked by VFS layer, always returning EFAULT on attempt to write
from mmap()'ed but not yet cached address range.  Normally it is
not a big problem, since after original failure VFS will retry the
write after reading the required data.  The problem becomes worse
in specific case when somebody tries to write into a file its own
mmap()'ed content from the same location.  In that situation the
only copy of the data is getting corrupted on the page fault and
the following retries only fixate the status quo.  Block cloning
makes this issue easier to reproduce, since it does not read the
old data, unlike traditional file copy, that may work by chance.

This patch provides the fill status to dmu_buf_fill_done(), that
in case of error can destroy the corrupted buffer as if no write
happened.  One more complication in case of block cloning is that
if error is possible during fill, dmu_buf_will_fill() must read
the data via fall-back to dmu_buf_will_dirty().  It is required
to allow in case of error restoring the buffer to a state after
the cloning, not not before it, that would happen if we just call
dbuf_undirty().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #15665
2024-02-20 15:53:02 -08:00
Tony Hutter
b62fd2cef9 ZTS: Skip cross-fs bclone tests if FreeBSD < 14.0
Skip cross filesystem block cloning tests on FreeBSD if running
less than version 14.0.  Cross filesystem copy_file_range() was
added in FreeBSD 14.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #15901
2024-02-16 09:33:26 -08:00
Tony Hutter
d92fbe2150 [zfs-2.2.3] ZTS: Use correct bclone module param name on FreeBSD
The bclone module names are not prefixed with 'zfs' on FreeBSD.
This was causing test failues.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
2024-02-16 09:33:05 -08:00
Bi11
a4978d2605 zdb: Fix false leak report for BRT objects
Fix a misreport in 'zdb -d' where it falsely marked
BRT objects as leaked.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Yuxin Wang <yuxinwang9999@gmail.com>
Closes #15882
2024-02-12 17:03:17 -08:00
Dex Wood
a6f6c881ff Add Ntfy notification support to ZED
This commit adds the zed_notify_ntfy() function and hooks it
into zed_notify(). This will allow ZED to send notifications
to ntfy.sh or a self-hosted Ntfy service, which can be received
on a desktop or mobile device. It is configured with ZED_NTFY_TOPIC,
ZED_NTFY_URL, and ZED_NTFY_ACCESS_TOKEN variables in zed.rc.

Reviewed-by: @classabbyamp
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Dex Wood <slash2314@gmail.com>
Closes #15584
2024-02-12 14:32:11 -08:00
Bi11
fc3d34bd08 BRT: Fix slop space calculation with block cloning
Similar to deduplication, the size of data duplicated by block cloning
should not be included in the slop space calculation.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Yuxin Wang <yuxinwang9999@gmail.com>
Closes #15874
2024-02-12 14:04:27 -08:00
Rob N
36116b4612 zfs list: add '-t fs' and '-t vol' options (#15883)
Because "filesystem" and "volume" are just too long!

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #15864
(cherry picked from commit a5a725440b)
2024-02-12 14:04:27 -08:00
Tony Hutter
b699dacb4a [zfs-2.2.3] Enable zfs_bclone_enabled on cp_files tests
cp_files_002_pos uses BRT, so enable block cloning in setup/cleanup.
This is only something we need to do in zfs-2.2.3, since 2.2.x ships
with block cloning disabled by default.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
2024-02-12 14:04:21 -08:00
the-Chain-Warden-thresh
d22bf6a9bd LUA: Backport CVE-2020-24370's patch
CVE-2020-24370 is a security vulnerability in lua. Although the CVE
description in CVE-2020-24370 said that this CVE only affected lua
5.4.0, according to lua this CVE actually existed since lua 5.2. The
root cause of this CVE is the negation overflow that occurs when you
try to take the negative of 0x80000000. Thus, this CVE also exists in
openzfs. Try to backport the fix to the lua in openzfs since the
original fix is for 5.4 and several functions have been changed.

https://github.com/advisories/GHSA-gfr4-c37g-mm3v
https://nvd.nist.gov/vuln/detail/CVE-2020-24370
https://www.lua.org/bugs.html#5.4.0-11
https://github.com/lua/lua/commit/a585eae6e7ada1ca9271607a4f48dfb1786

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: ChenHao Lu <18302010006@fudan.edu.cn>
Closes #15847
2024-02-08 15:22:16 -08:00
Cameron Harr
40e20d808c Add 'zpool status -e' flag to see unhealthy vdevs
When very large pools are present, it can be laborious to find
reasons for why a pool is degraded and/or where an unhealthy vdev
is. This option filters out vdevs that are ONLINE and with no errors
to make it easier to see where the issues are. Root and parents of
unhealthy vdevs will always be printed.

Testing:
ZFS errors and drive failures for multiple vdevs were simulated with
zinject.

Sample vdev listings with '-e' option
- All vdevs healthy
    NAME        STATE     READ WRITE CKSUM
    iron5       ONLINE       0     0     0

- ZFS errors
    NAME        STATE     READ WRITE CKSUM
    iron5       ONLINE       0     0     0
      raidz2-5  ONLINE       1     0     0
        L23     ONLINE       1     0     0
        L24     ONLINE       1     0     0
        L37     ONLINE       1     0     0

- Vdev faulted
    NAME        STATE     READ WRITE CKSUM
    iron5       DEGRADED     0     0     0
      raidz2-6  DEGRADED     0     0     0
        L67     FAULTED      0     0     0  too many errors

- Vdev faults and data errors
    NAME        STATE     READ WRITE CKSUM
    iron5       DEGRADED     0     0     0
      raidz2-1  DEGRADED     0     0     0
        L2      FAULTED      0     0     0  too many errors
      raidz2-5  ONLINE       1     0     0
        L23     ONLINE       1     0     0
        L24     ONLINE       1     0     0
        L37     ONLINE       1     0     0
      raidz2-6  DEGRADED     0     0     0
        L67     FAULTED      0     0     0  too many errors

- Vdev missing
    NAME        STATE     READ WRITE CKSUM
    iron5       DEGRADED     0     0     0
      raidz2-6  DEGRADED     0     0     0
        L67     UNAVAIL      3     1     0

- Slow devices when -s provided with -e
    NAME        STATE     READ WRITE CKSUM  SLOW
    iron5       DEGRADED     0     0     0     -
      raidz2-5  DEGRADED     0     0     0     -
        L10     FAULTED      0     0     0     0  external device fault
        L51     ONLINE       0     0     0    14

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Cameron Harr <harr1@llnl.gov>
Closes #15769
2024-02-08 15:22:16 -08:00
Mauricio Faria de Oliveira
9bb8d26bd5 zed: fix typo in variable ZED_POWER_OFF_ENCLO*US*RE_SLOT_ON_FAULT
Replace ENCLO_US_RE with ENCLO_SU_RE in the name of the variable.

Note this changes the user-visible string in zed.rc, thus might
break current users with the wrong string, but it's ~2 months
since zfs-2.2.0 tag is out, thus should not be widespread yet.

Mechanical change:

    $ grep -rl ZED_POWER_OFF_ENCLOUSRE_SLOT_ON_FAULT
    cmd/zed/zed.d/zed.rc
    cmd/zed/zed.d/statechange-slot_off.sh

    $ sed -i 's/ZED_POWER_OFF_ENCLOUSRE_SLOT_ON_FAULT/<linebreak>
                ZED_POWER_OFF_ENCLOSURE_SLOT_ON_FAULT/g' \
      cmd/zed/zed.d/zed.rc \
      cmd/zed/zed.d/statechange-slot_off.sh

    $ grep -rl ZED_POWER_OFF_ENCLOUSRE_SLOT_ON_FAULT
    $

Fixes 11fbcacf37
("zed: Add zedlet to power off slot when drive is faulted")

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Closes #15651
2024-02-08 15:22:16 -08:00
Umer Saleem
08fd5ccc38 Improve performance for zpool trim on linux
On Linux, ZFS uses blkdev_issue_discard in vdev_disk_io_trim to issue
trim command which is synchronous.

This commit updates vdev_disk_io_trim to use __blkdev_issue_discard,
which is asynchronous. Unfortunately there isn't any asynchronous
version for blkdev_issue_secure_erase, so performance of secure trim
will still suffer.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Umer Saleem <usaleem@ixsystems.com>
Closes #15843
2024-02-06 12:58:55 -08:00