With some pathological access patterns it is possible to make ZFS
accumulate almost unlimited amount of speculative prefetch ZIOs.
Combined with linear ABD allocations in RAIDZ code, it appears to
be possible to exhaust system KVA, triggering kernel panic.
Address this by introducing a system-wide counter of active prefetch
requests and blocking prefetch distance doubling per stream hits if
the number of active requests is higher that ~6% of ARC size.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14516
During snapshot deletion ZFS may issue several reads for each deadlist
to merge them into next snapshot's or pool's bpobj. Number of the dead
lists increases with number of snapshots. On HDD pools it may take
significant time during which sync thread is blocked.
This patch introduces prescient prefetch of required blocks for up to
128 deadlists ahead. Tests show reduction of time required to delete
dataset with 720 snapshots with randomly overwritten file on wide HDD
pool from 75-85 to 22-28 seconds.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Issue #14276Closes#14402
On FreeBSD this reduces this structure size from 64 to 56 bytes.
dnode_handle_t respectively reduces from 72 to 64 bytes. It sounds
like a waste to need 72 bytes to be able to relocate 808 bytes of
dnode_t, which relocation on FreeBSD is not even supported.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14317
I've noticed that some of those counters are used in hot paths like
dnode_hold_impl(), and results of this change is visible in profiler.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#14198
It is protected by z_hold_locks, so we do not need more serialization,
simple integer math should be fine.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#14196
Microzap on-disk format does not include a hash tree, expecting one to
be built in RAM during mzap_open(). The built tree is linked to DMU
user buffer, freed when original DMU buffer is dropped from cache. I've
found that workloads accessing many large directories and having active
eviction from DMU cache spend significant amount of time building and
then destroying the trees. I've also found that for each 64 byte mzap
element additional 64 byte tree element is allocated, that is a waste
of memory and CPU caches.
Improve memory efficiency of the hash tree by switching from AVL-tree
to B-tree. It allows to save 24 bytes per element just on pointers.
Save 32 bits on mze_hash by storing only upper 32 bits since lower 32
bits are always zero for microzaps. Save 16 bits on mze_chunkid, since
microzap can never have so many elements. Respectively with the 16 bits
there can be no more than 16 bits of collision differentiators. As
result, struct mzap_ent now drops from 48 (rounded to 64) to 8 bytes.
Tune B-trees for small data. Reduce BTREE_CORE_ELEMS from 128 to 126
to allow struct zfs_btree_core in case of 8 byte elements to pack into
2KB instead of 4KB. Aside of the microzaps it should also help 32bit
range trees. Allow custom B-tree leaf size to reduce memmove() time.
Split zap_name_alloc() into zap_name_alloc() and zap_name_init_str().
It allows to not waste time allocating/freeing memory when processing
multiple names in a loop during mzap_open().
Together on a pool with 10K directories of 1800 files each and DMU
cache limited to 128MB this reduces time of `find . -name zzz` by 41%
from 7.63s to 4.47s, and saves additional ~30% of CPU time on the DMU
cache reclamation.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14039
(cherry picked from commit 9dcdee7889)
The zio returned from arc_write() in dmu_objset_sync() uses
zio_nowait(). However we may reach the end of dsl_dataset_sync()
which checks if we need to activate features in the filesystem
without knowing if that zio has even run through the ZIO pipeline yet.
In that case we will flag features to be activated in
dsl_dataset_block_born() but dsl_dataset_sync() has already
completed its run and those features will not actually be activated.
Mitigate this by moving the feature activation code in
dsl_dataset_sync_done(). Also add new ASSERTs in
dsl_scan_visitbp() checking if a block contradicts any filesystem
flags.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#13816
Open files, which aren't present in the snapshot, which is being
roll-backed to, need to disappear from the visible VFS image of
the dataset.
Kernel provides d_drop function to drop invalid entry from
the dcache, but inode can be referenced by dentry multiple dentries.
The introduced zpl_d_drop_aliases function walks and invalidates
all aliases of an inode.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
Closes#9600Closes#14070
Currently, additional/extra copies are created for metadata in
addition to the redundancy provided by the pool(mirror/raidz/draid),
due to this 2 times more space is utilized per inode and this decreases
the total number of inodes that can be created in the filesystem. By
setting redundant_metadata to none, no additional copies of metadata
are created, hence can reduce the space consumed by the additional
metadata copies and increase the total number of inodes that can be
created in the filesystem. Additionally, this can improve file create
performance due to the reduced amount of metadata which needs
to be written.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Signed-off-by: Akash B <akash-b@hpe.com>
Closes#13680
Original Log Size Limit implementation blocked all writes in case of
limit reached until the TXG is committed and the log is freed. It
caused huge delays and following speed spikes in application writes.
This implementation instead smoothly throttles writes, using exactly
the same mechanism as used for dirty data.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: jxdking <lostking2008@hotmail.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Issue #12284Closes#13476
This reverts commit 34dbc618f5. While this
change resolved the lock contention observed for certain workloads, it
inadventantly reduced the maximum hash inserts/removes per second. This
appears to be due to the slightly higher acquisition cost of a rwlock vs
a mutex.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
- Some optimizations for bqueue enqueue/dequeue.
- Added a fix to prevent deadlock when both bqueue_enqueue_impl()
and bqueue_dequeue() waits for signal to be triggered.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#13855
These are used by userspace, so should live in a public header
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#12116
When iterating through children physical ashifts for vdev, prefer
ones above the maximum logical ashift, that we can actually use,
but within the administrator defined maximum.
When selecting top-level vdev ashift, do not set it to the defined
maximum in case physical ashift is even higher, but just ignore one.
Using the maximum does not prevent misaligned writes, but reduces
space efficiency. Since ZFS tries to write data sequentially and
aggregates the writes, in many cases large misanigned writes may be
not as bad as the space penalty otherwise.
Allow internal physical ashifts for vdevs higher than SHIFT_MAX.
May be one day allocator or aggregation could benefit from that.
Reduce zfs_vdev_max_auto_ashift default from 16 (64KB) to 14 (16KB),
so that ZFS may still use bigger ashifts up to SHIFT_MAX (64KB),
but only if it really has to or explicitly told to, but not as an
"optimization".
There are some read-intensive NVMe SSDs that report Preferred Write
Alignment of 64KB, and attempt to build RAIDZ2 of those leads to a
space inefficiency that can't be justified. Instead these changes
make ZFS fall back to logical ashift of 12 (4KB) by default and
only warn user that it may be suboptimal for performance.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#13798
zfs_wrlog_data_max
The upper limit of TX_WRITE log data. Once it is reached,
write operation is blocked, until log data is cleared out
after txg sync. It only counts TX_WRITE log with WR_COPIED
or WR_NEED_COPY.
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: jxdking <lostking2008@hotmail.com>
Closes#12284
Use dp_dirty_pertxg[] for txg_kick(), instead of dp_dirty_total in
original code. Extra parameter "txg" is added for txg_kick(), thus it
knows which txg to kick. Also txg_kick() call is moved from
dsl_pool_need_dirty_delay() to dsl_pool_dirty_space() so that we can
know the txg number assigned for txg_kick().
Some unnecessary code regarding dp_dirty_total in txg_sync_thread() is
also cleaned up.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: jxdking <lostking2008@hotmail.com>
Closes#12274
- Some optimizations for bqueue enqueue/dequeue.
- Added a fix to prevent deadlock when both bqueue_enqueue_impl()
and bqueue_dequeue() waits for signal to be triggered.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes#13855
Without this patch, the
ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf));
at the beginning of dbuf_assign_arcbuf can panic
if the object type is a DMU_OT_NEWTYPE that has
DMU_OT_METADATA set.
While we're at it, fix DMU_OT_IS_ENCRYPTED as well.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Christian Schwarz <christian.schwarz@nutanix.com>
Closes#13842
Add physical device size/capacity only for physical devices in
'zpool list -v' instead of displaying "-" in the SIZE column.
This would make it easier to see the individual device capacity and
to determine which spares are large enough to replace which devices.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Dipak Ghosh <dipak.ghosh@hpe.com>
Signed-off-by: Akash B <akash-b@hpe.com>
Closes#12561Closes#13106
Special allocation class or dedup vdevs may have roughly the same
performance as L2ARC vdevs. Introduce a new tunable to exclude those
buffers from being cacheable on L2ARC.
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#11761Closes#12285
Users were seeing floods of `config_sync` events when autoexpand was
enabled. This happened because all "disk status change" udev events
invoke the autoexpand codepath, which calls zpool_relabel_disk(),
which in turn cause another "disk status change" event to happen,
in a feedback loop. Note that "disk status change" happens every time
a user calls close() on a block device.
This commit breaks the feedback loop by only allowing an autoexpand
to happen if the disk actually changed size.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes: #7132Closes: #7366Closes#13729
Restructure the code in zfs_log_xvattr() to use a lr_attr_end
structure when accessing lr_attr_t elements located after the
variable sized array. This makes the code more understandable
and resolves the accessing beyond the end of the field warnings.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13528Closes#13575
It may happen that scan bookmark points to a block that was turned
into a part of a big hole. In such case dsl_scan_visitbp() may skip
it and dsl_scan_check_resume() will not be called for it. As result
new scan suspend won't be possible until the end of the object, that
may take hours if the object is a multi-terabyte ZVOL on a slow HDD
pool, stretching TXG to all that time, creating all sorts of problems.
This patch changes the resume condition to any greater or equal block,
so even if we miss the bookmarked block, the next one we find will
delete the bookmark, allowing new suspend.
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Block statistics calculation during scrub I/O issue in case of sorted
scrub accounted ditto blocks several times. Embedded blocks on other
side were not accounted at all. This change moves the accounting from
issue to scan stage, that fixes both problems and also allows to avoid
pool-wide locking and the lock contention it created.
Since this statistics is quite specific and is not even exposed now
anywhere, disable its calculation by default to not waste CPU time.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13579
- Introduce first element offset within a leaf. It allows to reduce
by ~50% average memmove() size when adding/removing elements. If the
added/removed element is in the first half of the leaf, we may shift
elements before it and adjust the bth_first instead of moving more
elements after it.
- Use memcpy() instead of memmove() when we know there is no overlap.
- Switch from uint64_t to uint32_t. It does not limit anything,
but 32-bit arches should appreciate it greatly in hot paths.
- Store leaf capacity in struct btree to avoid 64-bit divisions.
- Adjust zfs_btree_insert_into_leaf() to always result in balanced
leaves after splitting, no matter where the new element was inserted.
Not that we care about it much, but it should also allow B-trees with
as little as two elements per leaf instead of 4 previously.
When scrubbing pool of 12 SSDs, storing 1.5TB of 4KB zvol blocks this
reduces amount of time spent in memmove() inside the scan thread from
13.7% to 5.7% and total scrub time by ~15 seconds out of 9 minutes.
It should also reduce spacemaps load time, but I haven't measured it.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13582
- Reduce size and comparison complexity of q_exts_by_size B-tree.
Previous code used two 64-bit divisions and many other operations to
compare two B-tree elements. It created enormous overhead. This
implementation moves the math to the upper level and stores the score
in the B-tree elements themselves. Since all that we need to store in
that B-tree is the extent score and offset, those can fit into single
8 byte value instead of 24 bytes of q_exts_by_addr element and can be
compared with single operation.
- Better decouple secondary tree logic from main range_tree by moving
rt_btree_ops and related functions into dsl_scan.c as ext_size_ops.
Those functions are very small to worry about the code duplication and
range_tree does not need to know details such as rt_btree_compare.
- Instead of accounting number of pending bytes per pool, that needs
atomic on global variable per block, account the number of non-empty
per-vdev queues, that change much more rarely.
- When extent scan is interrupted by TXG end, continue it in the next
TXG instead of selecting next best extent. It allows to avoid leaving
one truncated (and so likely not the best any more) extent each TXG.
On top of some other optimizations this saves about 1.5 minutes out of
10 to scrub pool of 12 SSDs, storing 1.5TB of 4KB zvol blocks.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <caputit1@tcnj.edu>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13576
- Make prefetch distance adaptive: up to 4MB prefetch doubles for
every, hit same as before, but after that it grows by 1/8 every time
the prefetch read does not complete in time to satisfy the demand.
My tests show that 4MB is sufficient for wide NVMe pool to saturate
single reader thread at 2.5GB/s, while new 64MB maximum allows the
same thread to reach 1.5GB/s on wide HDD pool. Further distance
increase may increase speed even more, but less dramatic and with
higher latency.
- Allow early reuse of inactive prefetch streams: streams that never
saw hits can be reused immediately if there is a demand, while others
can be reused after 1s of inactivity, starting with the oldest. After
2s of inactivity streams are deleted to free resources same as before.
This allows by several times increase strided read performance on HDD
pool in presence of simultaneous random reads, previously filling the
zfetch_max_streams limit for seconds and so blocking most of prefetch.
- Always issue intermediate indirect block reads with SYNC priority.
Each of those reads if delayed for longer may delay up to 1024 other
block prefetches, that may be not good for wide pools.
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#13452
Previous flushing algorithm limited only total number of log blocks to
the minimum of 256K and 4x number of metaslabs in the pool. As result,
system with 1500 disks with 1000 metaslabs each, touching several new
metaslabs each TXG could grow spacemap log to huge size without much
benefits. We've observed one of such systems importing pool for about
45 minutes.
This patch improves the situation from five sides:
- By limiting maximum period for each metaslab to be flushed to 1000
TXGs, that effectively limits maximum number of per-TXG spacemap logs
to load to the same number.
- By making flushing more smooth via accounting number of metaslabs
that were touched after the last flush and actually need another flush,
not just ms_unflushed_txg bump.
- By applying zfs_unflushed_log_block_pct to the number of metaslabs
that were touched after the last flush, not all metaslabs in the pool.
- By aggressively prefetching per-TXG spacemap logs up to 16 TXGs in
advance, making log spacemap load process for wide HDD pool CPU-bound,
accelerating it by many times.
- By reducing zfs_unflushed_log_block_max from 256K to 128K, reducing
single-threaded by nature log processing time from ~10 to ~5 minutes.
As further optimization we could skip bumping ms_unflushed_txg for
metaslabs not touched since the last flush, but that would be an
incompatible change, requiring new pool feature.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12789
Use error thresholds from policy to control whether to scrub data
and/or metadata. If threshold is set to UINT64_MAX, then caller
probably does not care about result and we may skip that part.
By default import neither set the data error threshold nor read
the error counter, so skip the data scrub for faster import.
Metadata are still scrubbed and fail if even single error found.
While there just for symmetry return number of metadata errors in
case threshold is not set to zero and we haven't reached it.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#13022
It is wrong for arc_write_ready() to use zfs_abd_scatter_enabled to
decide whether to reallocate/copy the buffer, because the answer is
OS-specific and depends on the buffer size. Instead of that use
abd_size_alloc_linear(), moved into public header.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12425
The only reason for spa_config_*() to use refcount instead of simple
non-atomic (thanks to scl_lock) variable for scl_count is tracking,
hard disabled for the last 8 years. Switch to simple int scl_count
reduces the lock hold time by avoiding atomic, plus makes structure
fit into single cache line, reducing the locks contention.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes#12287
As of the Linux 5.19 kernel an identically named zap_flags_t typedef
is declared in the include/linux/mm_types.h linux header. Sadly,
the inclusion of this header cannot be easily avoided. To resolve
the conflict a #define is used to remap the name in the OpenZFS
sources when building against the Linux kernel.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13515
This was breaking the kmod port build on FreeBSD with Clang 13.
Use the same trick as we do for ASSERT() to make DNODE_VERIFY() use
its parameter at compile time without actually using it at run time
in non-debug builds.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#13507
Holding a dbuf is a common operation which can become highly contended
in dbuf_find() when acquiring the dbuf hash mutex. This is particularly
true on Linux when reading/writing volumes since by default up to 32
threads from the zvol_taskq may be taking a hold of the same dbuf.
This should also be observable on FreeBSD as long as there are enough
processes accessing the volume concurrently.
This is further aggregrated by the fact that only the block id will
be unique when calculating the dbuf hash for a single volume. The
objset id, object id, and level will be the same for data blocks.
This has been observed to result in a somehwat less than uniform hash
distribution and a longer than expected max hash chain depth (~20)
on a large memory system (256 GB) using volumes.
This commit improves the siutation by switching the hash mutex to
an rwlock to allow concurrent lookups, and increasing DBUF_RWLOCKS
from 2048 to 8192 to further reduce the odds of a hash collision.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13405
The only zdb utility require to read metaslab-related data during
read-only pool import because of spacemaps validation. Add global
variable which will allow zdb read spacemaps in case of readonly
import mode.
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Fedor Uporov <fuporov.vstack@gmail.com>
Closes#9095Closes#12687
When unlinking multiple files from a pool at 100% capacity, it was
possible for ENOSPC to be returned after the first unlink. e.g.
rm -f /mnt/fs/test1.0.0 /mnt/fs/test1.1.0 /mnt/fs/test1.2.0
rm: cannot remove '/mnt/fs/test1.1.0': No space left on device
rm: cannot remove '/mnt/fs/test1.2.0': No space left on device
After waiting for the pending deferred frees from the first unlink to
be processed the remaining files can then be unlinked. This is caused
by the quota limit in dsl_dir_tempreserve_impl() being temporarily
decreased to the allocatable pool capacity less any deferred free
space.
This is resolved using the existing mechanism of returning ERESTART
when over quota as long as we know enough space will shortly be
available after processing the pending deferred frees.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <freqlabs@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13172
For kernel to send snapshot mount/unmount events to zed.
For kernel to send symlink creates/removes on zvol plumbing.
(/dev/run/dsk/zvol/$pool/$zvol -> /dev/diskX)
If zed misses the ENODEV, all errors after are EINVAL. Treat any error
as kernel module failure.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#12416
When the eviction thread goes to shrink an ARC state, it allocates a set
of marker buffers used to hold its place in the state's sublists.
This can be problematic in low memory conditions, since
1) the allocation can be substantial, as we allocate NCPU markers;
2) on at least FreeBSD, page reclamation can block in
arc_wait_for_eviction()
In particular, in stress tests it's possible to hit a deadlock on
FreeBSD when the number of free pages is very low, wherein the system is
waiting for the page daemon to reclaim memory, the page daemon is
waiting for the ARC eviction thread to finish, and the ARC eviction
thread is blocked waiting for more memory.
Try to reduce the likelihood of such deadlocks by pre-allocating markers
for the eviction thread at ARC initialization time. When evicting
buffers from an ARC state, check to see if the current thread is the ARC
eviction thread, and use the pre-allocated markers for that purpose
rather than dynamically allocating them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: George Amanakis <gamanakis@gmail.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes#12985
Verify that all empty sectors are zero filled before using them to
calculate parity. Failure to do so can result in incorrect parity
columns being generated and written to disk if the contents of an
empty sector are non-zero. This was possible because the checksum
only protects the data portions of the buffer, not the empty sector
padding.
This issue has been addressed by updating raidz_parity_verify() to
check that all dRAID empty sectors are zero filled. Any sectors
which are non-zero will be fixed, repair IO issued, and a checksum
error logged. They can then be safely used to verify the parity.
This specific type of damage is unlikely to occur since it requires
a disk to have silently returned bad data, for an empty sector, while
performing a scrub. However, if a pool were to have been damaged
in this way, scrubbing the pool with this change applied will repair
both the empty sector and parity columns as long as the data checksum
is valid. Checksum errors will be reported in the `zpool status`
output for any repairs which are made.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#12857
When using lseek(2) to report data/holes memory mapped regions of
the file were ignored. This could result in incorrect results.
To handle this zfs_holey_common() was updated to asynchronously
writeback any dirty mmap(2) regions prior to reporting holes.
Additionally, while not strictly required, the dn_struct_rwlock is
now held over the dirty check to prevent the dnode structure from
changing. This ensures that a clean dnode can't be dirtied before
the data/hole is located. The range lock is now also taken to
ensure the call cannot race with zfs_write().
Furthermore, the code was refactored to provide a dnode_is_dirty()
helper function which checks the dnode for any dirty records to
determine its dirtiness.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #11900Closes#12724
prng32_bounded() is available to kernel only on FreeBSD 13+.
Call inline random_get_pseudo_bytes() with correct pointer type.
To be consistent, apply to Linux as well.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Martin Matuska <mm@FreeBSD.org>
Closes#12282
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
It turns out that layouts of union bitfields are a pain, and the
current code results in an inconsistent layout between BE and LE
systems, leading to zstd-active datasets on one erroring out on
the other.
Switch everyone over to the LE layout, and add compatibility code
to read both.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#12008Closes#12022
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
Instead of clearing stats inside arc_buf_alloc_impl() do it inside
arc_hdr_alloc() and arc_release(). It fixes statistics being wiped
every time a new dbuf is filled from the ARC.
Remove b_l1hdr.b_l2_hits. L2ARC hits are accounted at b_l2hdr.b_hits.
Since the hits are accounted under hash lock, replace atomics with
simple increments.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12422
Use atomic_load_64() for zfs_refcount_count() to prevent torn reads
on 32-bit platforms. On 64-bit ones it should not change anything.
When built with ZFS_DEBUG but running without tracking enabled use
atomics instead of mutexes same as for builds without ZFS_DEBUG.
Since rc_tracked can't change live we can check it without lock.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#12420
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