CodeQL's cpp/constant-comparison query from its security-and-extended
query set reported 4 instances where we have comparions that always
evaluate the same way.
In `draid_config_by_type()`, we have an early `if (nparity == 0)` check
that returns `EINVAL`, making a later `if (nparity == 0 || nparity >
VDEV_DRAID_MAXPARITY)` partially redundant. The later check prints an
error message when parity is 0, but the early check does not. This is
not useful feedback, so we move the later check to the place where the
early check runs to replace the early check.
In `perform_thread_merge()`, we return when `num_threads == 0`. After
that block, we do `if (num_threads > 0) {`, which will always be true.
We remove the `if` statement.
In `sa_modify_attrs()`, we have a loop condition that is `k != 2`, but
at the end of the loop, we have `if (k == 0 && hdl->sa_spill)` followed
by an else that does a break. The result is that k != 2 will never be
evaluated when it is false. We drop the comparison.
In `zap_leaf_array_read()`, we have a for loop condition that is `i <
ZAP_LEAF_ARRAY_BYTES && len > 0`. However, that loop itself is in a loop
that is `while (len > 0)` and while the value of len is decremented
inside the loop, when `len == 0`, it will return, such that `len > 0`
inside the loop condition will always be true. We drop that part of the
condition.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14575
Clang's static analyzer reports that if a `blkid == DMU_SPILL_BLKID` is
passed, then we can have a NULL pointer dereference when either
->dn_have_spill or `DNODE_FLAG_SPILL_BLKPTR` is not set. This should not
happen. We add an `ASSERT()` to suppress reports about NULL pointer
dereferences.
Originally, I wanted to use one or two IMPLY statements on
pre-conditions before the call to `dbuf_findbp()`, but Clang's static
analyzer did not understand it.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14575
Clang's static analyzer pointed out that we can have a NULL pointer
dereference if we ever attempt to split a vdev that has only 1 child. If
that happens, we are left with zero children, but then try to access a
non-existent child. Calling vdev_split() on a vdev with only 1 child
should be impossible due to how the code is structured. If this ever
happens, it would be best to stop execution immediately even in a
production environment to allow for the best possible chance of recovery
by an expert, so we use `VERIFY3U()` instead of `ASSERT3U()`.
Unfortunately, while that defensive assertion will prevent execution
from ever reaching the NULL pointer dereference, Clang's static analyzer
does not realize that, so we add an `ASSERT()` to inform it of this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14575
Clang's static analyzer reports a possible NULL pointer dereference in
abd_get_size() when called from vdev_draid_map_alloc_write() called from
vdev_draid_map_alloc_row() and vdc->vdc_nparity == 0. This should be
impossible, so we add an assertion to silence the defect report.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14575
Traditionally ARC adaptation was limited to MRU/MFU distribution. But
for years people with metadata-centric workload demanded mechanisms to
also manage data/metadata distribution, that in original ZFS was just
a FIFO. As result ZFS effectively got separate states for data and
metadata, minimum and maximum metadata limits etc, but it all required
manual tuning, was not adaptive and in its heart remained a bad FIFO.
This change removes most of existing eviction logic, rewriting it from
scratch. This makes MRU/MFU adaptation individual for data and meta-
data, same as the distribution between data and metadata themselves.
Since most of required states separation was already done, it only
required to make arcs_size state field specific per data/metadata.
The adaptation logic is still based on previous concept of ghost hits,
just now it balances ARC capacity between 4 states: MRU data, MRU
metadata, MFU data and MFU metadata. To simplify arc_c changes instead
of arc_p measured in bytes, this code uses 3 variable arc_meta, arc_pd
and arc_pm, representing ARC balance between metadata and data, MRU and
MFU for data, and MRU and MFU for metadata respectively as 32-bit fixed
point fractions. Since we care about the math result only when need to
evict, this moves all the logic from arc_adapt() to arc_evict(), that
reduces per-block overhead, since per-block operations are limited to
stats collection, now moved from arc_adapt() to arc_access() and using
cheaper wmsums. This also allows to remove ugly ARC_HDR_DO_ADAPT flag
from many places.
This change also removes number of metadata specific tunables, part of
which were actually not functioning correctly, since not all metadata
are equal and some (like L2ARC headers) are not really evictable.
Instead it introduced single opaque knob zfs_arc_meta_balance, tuning
ARC's reaction on ghost hits, allowing administrator give more or less
preference to metadata without setting strict limits.
Some of old code parts like arc_evict_meta() are just removed, because
since introduction of ABD ARC they really make no sense: only headers
referenced by small number of buffers are not evictable, and they are
really not evictable no matter what this code do. Instead just call
arc_prune_async() if too much metadata appear not evictable.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14359
Otherwise, we can get a deadlock that looks like this:
1. fsync() grabs spa_config_enter(zilog->zl_spa, SCL_STATE, lwb,
RW_READER) as part of zil_lwb_write_issue() . It then blocks on the
txg_sync when a flush fails from a drive power cycling.
2. The txg_sync then blocks on the pool suspending due to the loss of
too many disks.
3. zpool clear then blocks on spa_config_enter(spa, SCL_STATE |
SCL_L2ARC | SCL_ZIO, spa, RW_WRITER) because it is a writer.
The disks cannot be brought online due to fsync() holding that lock and
the user gets upset since fsync() is uninterruptibly blocked inside the
kernel.
We need to grab the lock for vdev_lookup_top(), but we do not need to
hold it while there is outstanding IO.
This fixes a regression introduced by
1ce23dcaff.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Sponsored-By: Wasabi Technology, Inc.
Closes#14519
The intent is that this is like ENOTSUP, but specifically for when
something can't be done because we have no support for the requested
crypto parameters; eg unlocking a dataset or receiving a stream
encrypted with a suite we don't support.
Its not intended to be recoverable without upgrading ZFS itself.
If the request could be made to work by enabling a feature or modifying
some other configuration item, then some other code should be used.
load-key: In the future we might have more crypto suites (ie new values
for the `encryption` property. Right now trying to load a key on such
a future crypto suite will look up suite parameters off the end of the
crypto table, resulting in misbehaviour and/or crashes (or, with debug
enabled, trip the assertion in `zio_crypt_key_unwrap`).
Instead, lets check the value we got from the dataset, and if we can't
handle it, abort early.
recv: When receiving a raw stream encrypted with an unknown crypto
suite, `zfs recv` would report a generic `invalid backup stream`
(EINVAL). While technically correct, its not super helpful, so lets
ship a more specific error code and message.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#14577
by placing the most common use case (no special vdevs) first and avoid
allocating new variables.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#14494Closes#14563
dc5c8006f6 was recently merged to prefetch
up to 128 deadlists. Unfortunately, a loop was missing an increment,
such that it will prefetch all deadlists. The performance properties of
that patch probably should be re-evaluated.
This was caught by CodeQL's cpp/constant-comparison check in an
experimental branch where I am testing the security-and-extended
queries. It complained about the `i < 128` part of the loop condition
always evaluating to the same thing. The standard CodeQL configuration
we use missed this because it does not include that check.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14573
The skeleton file module/icp/include/generic_impl.c can be used for
iterating over different implementations of algorithms.
It is used by SHA256, SHA512 and BLAKE3 currently.
The Solaris SHA2 implementation got replaced with a version which is
based on public domain code of cppcrypto v0.10.
These assembly files are taken from current openssl master:
- sha256-x86_64.S: x64, SSSE3, AVX, AVX2, SHA-NI (x86_64)
- sha512-x86_64.S: x64, AVX, AVX2 (x86_64)
- sha256-armv7.S: ARMv7, NEON, ARMv8-CE (arm)
- sha512-armv7.S: ARMv7, NEON (arm)
- sha256-armv8.S: ARMv7, NEON, ARMv8-CE (aarch64)
- sha512-armv8.S: ARMv7, ARMv8-CE (aarch64)
- sha256-ppc.S: Generic PPC64 LE/BE (ppc64)
- sha512-ppc.S: Generic PPC64 LE/BE (ppc64)
- sha256-p8.S: Power8 ISA Version 2.07 LE/BE (ppc64)
- sha512-p8.S: Power8 ISA Version 2.07 LE/BE (ppc64)
Tested-by: Rich Ercolani <rincebrain@gmail.com>
Tested-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13741
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
openzfsonwindows/openzfs#206 found that it is possible to trip
`VERIFY(list_is_empty(&lwb->lwb_itxs))` when a `zil_commit()` is delayed
by the scheduler long enough for a parallel `zil_suspend()` operation to
exit `zil_commit_impl()`. This is a data race. To prevent this, we
introduce a `zilog->zl_suspend_lock` rwlock to ensure that all
outstanding `zil_commit()` operations finish before `zil_suspend()`
begins and that subsequent operations fallback to `txg_wait_synced()`
after `zil_suspend()` has begun.
On `PREEMPT_RT` Linux kernels, the `rw_enter()` implementation suffers
from writer starvation. This means that a ZIL intensive system can delay
`zil_suspend()` indefinitely. This is a pre-existing problem that
affects everything that uses rw locks, so it needs to be addressed in
the SPL. However, builds against `PREEMPT_RT` Linux kernels are
currently broken due to a GPL symbol issue (#11097), so we can safely
disregard that issue for now.
Reported-by: Arun KV <arun.kv@datacore.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14514
I forgot to remove the corresponding kmem_free() from zfs_kmod_fini() in
9a14ce43c3. Clang's static analyzer did
not complain, but the Coverity scan that was run after the patch was
merged did.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reported-by: Coverity (CID-1535275)
Closes#14556
We tripped `ASSERT(error == ENOENT || error == EEXIST || error ==
EALREADY)` in `zil_lwb_commit()` at Klara when doing robustness testing
of ZIL against drive power cycles.
That assertion presumably exists because when this code was written, the
only errors expected from here were EIO, ENOENT, EEXIST and EALREADY,
with EIO having its own handling before the assertion. However, upon
doing a manual depth first search traversal of the source tree, it turns
out that a large number of unexpected errors are possible here. In
theory, EINVAL and ENOSPC can come from dnode_hold_impl(). However, most
unexpected errors originate in the block layer and come to us from
zio_wait() in various ways. One way is ->zl_get_data() -> dmu_buf_hold()
-> dbuf_read() -> zio_wait().
From vdev_disk.c on Linux alone, zio_wait() can return the unexpected
errors ENXIO, ENOTSUP, EOPNOTSUPP, ETIMEDOUT, ENOSPC, ENOLINK,
EREMOTEIO, EBADE, ENODATA, EILSEQ and ENOMEM
This was only observed after what have been likely over 1000 test
iterations, so we do not expect to reproduce this again to find out what
the error code was. However, circumstantial evidence suggests that the
error was ENXIO.
When ENXIO or any other unexpected error occurs, the `fsync()` or
equivalent operation that called zil_commit() will return success, when
in fact, dirty data has not been committed to stable storage. This is a
violation of the Single UNIX Specification.
The code should be able to handle this and any other unknown error by
calling `txg_wait_synced()`. In addition to changing the code to call
txg_wait_synced() on unexpected errors instead of returning, we modify
it to print information about unexpected errors to dmesg.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Sponsored-By: Wasabi Technology, Inc.
Closes#14532
Clang's static analyzer claims that dereferencing ds in
dmu_objset_create_impl_dnstats() could cause a NULL pointer dereference
when a previous NULL check confirms that it is NULL. It is only NULL on
the MOS, for which dmu_objset_userused_enabled(os) should always return
false, so ds will never be dereferenced when it is NULL. We add an
assertion to suppress this warning.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14470
Clang's static analyzer claims that dbuf_hold_copy() will have a NULL
pointer dereference in data->b_data when called by dbuf_hold_impl().
This is impossible because data is dr->dt.dl.dr_data, which is non-NULL
whenever db->db_level == 0, which is always the case whenever
dbuf_hold_impl() calls dbuf_hold_copy(). We add an assertion to suppress
the complaint.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14470
This avoids a call to kmem_alloc() during module load. It also
suppresses a defect report from Clang's static analyzer that claims that
we will have a NULL pointer dereference in zfsdev_state_init() because
it does not understand that this has already been allocated in
zfs_kmod_init().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14470
Clang's static analyzer points out that when IS_SA_BONUSTYPE(type) is
true and .sa_length is 0 for an attribute, we have a NULL pointer
dereference. We suppress this with an IMPLY() statement.
This was also identified by Coverity.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reported-by: Coverity (CID-1017954)
Closes#14470
Clang's static analyzer informs us of multiple NULL pointer dereferences
involving zio_checksum_error_impl().
The first is a NULL pointer dereference if bp is NULL and ci->ci_flags &
ZCHECKSUM_FLAG_EMBEDDED is false, but bp is NULL implies that
ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED is true, so we add an IMPLY()
statement to suppress the report.
The second and third are identical, and are duplicated because while the
NULL pointer dereference occurs in zio_checksum_gang_verifier(), it is
called by zio_checksum_error_impl() and there is a report for each of
the two functions. The reports state that when bp is NULL, ci->ci_flags
& ZCHECKSUM_FLAG_EMBEDDED is true and checksum is not
ZIO_CHECKSUM_LABEL, we also have a NULL pointer dereference. bp is NULL
should imply that checksum == ZIO_CHECKSUM_LABEL, so we add an IMPLY()
statement to suppress the second report. The two reports are
functionally identical.
A fourth variation of this was also reported by Coverity. It occurs when
checksum == ZIO_CHECKSUM_ZILOG2.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reported-by: Coverity (CID-1524672)
Closes#14470
Commit 34ce4c4 made zfeature_active() non-static. This is not required.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#14546
Hole detection in the zio compression code allows us to
opportunistically skip compression on holes. We can go a step further
by not doing memory allocations on holes either.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Sponsored-by: Wasabi Technology, Inc.
Closes#14500
In the case of a regular compilation, the compiler
raises a warning for a dsl_deadlist_merge function, that
the stack size is to large. In debug build this can
generate an error.
Move large structures to heap.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes#14524
Otherwise the dataset may be freed after the last dmu_buf_rele() leading
to a panic.
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#14522Closes#14523
Clang's static analyzer correctly identified a NULL pointer dereference
in zio_ready() when ZIO_FLAG_NODATA has been set on a zio that is
missing a block pointer. The NULL pointer dereference occurs because we
have logic intended to disable ZIO_FLAG_NODATA when it has been set on a
gang block.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14469
When dn->dn_bonus == NULL, dmu_bonus_hold_by_dnode() will unlock its
read lock on dn->dn_struct_rwlock and grab a write lock. This can be
micro-optimized by calling rw_tryupgrade().
Linux will not benefit from this since it does not support rwlock
upgrades, but FreeBSD will.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14517
With commit 34ce4c42f applied, there is no need for eee9362a7.
Revert that aside from the test. All tests introduced in those commits
pass.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes#14502
spa_sync() currently grabs the write lock due to an old hack that is
documented by a comment:
We need the write lock here because, for aux vdevs,
calling vdev_config_dirty() modifies sav_config.
This is ugly and will become unnecessary when we
eliminate the aux vdev wart by integrating all vdevs
into the root vdev tree.
This has lead to deadlocks in rare edge cases from holding the write
lock. We can reduce incidence of these deadlocks by not grabbing the
write lock on pools without auxillary vdevs.
Sponsored-By: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Closes#14282
Add handling to dmu_object_next for the case where *objectp == 0.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#14479
Clang's static analyzer incorrectly complains about an undefined value
here when lr->lr_common.lrc_txtype == TX_SYMLINK and txtype ==
TX_CREATE. This is impossible, because of this line:
txtype = (lr->lr_common.lrc_txtype & ~TX_CI((uint64_t)0x1 << 63));
Changing the code to compare against txtype suppresses the report.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14472
As of the 4.13 kernel filemap_range_has_page() can be used to
check if there is a page mapped in a given file range. When
available this interface should be used which eliminates the
need for the zp->z_is_mapped boolean.
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14493
strlcat() is supposed to be given the length of the destination buffer,
including the existing contents. Unfortunately, I had been overzealous
when I wrote a51288aabb, since I gave it
the length of the destination buffer, minus the existing contents. This
likely caused a regression on large strings.
On the topic of being overzealous, the use of strlcat() in
dmu_send_estimate_fast() was unnecessary because recv_clone_name is a
fixed length string. We continue using strlcat() mostly as defensive
programming, in case the string length is ever changed, even though it
is unnecessary.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14476
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
Debugging reported NULL de-reference panic in dnode_hold_impl() I found
that for certain types of errors arc_read() may only return error code,
but not properly report it via done and pio arguments. Lack of done
calls may result in reference and/or memory leaks in higher level code.
Lack of error reporting via pio may result in unnoticed errors there.
For example, dbuf_read(), where dbuf_read_impl() ignores arc_read()
return, relies completely on the pio mechanism and missed the errors.
This patch makes arc_read() to always call done callback and always
propagate errors to parent zio, if either is provided.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes#14454
The PVS Studio 2016 FreeBSD kernel report stated:
\contrib\opensolaris\uts\common\fs\zfs\spa.c (1341): error V595: The 'spa->spa_spares.sav_vdevs' pointer was utilized before it was verified against nullptr. Check lines: 1341, 1342.
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\spa.c (1355): error V595: The 'spa->spa_l2cache.sav_vdevs' pointer was utilized before it was verified against nullptr. Check lines: 1355, 1357.
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\spa.c (1398): error V595: The 'spa->spa_spares.sav_vdevs' pointer was utilized before it was verified against nullptr. Check lines: 1398, 1408.
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\spa.c (1583): error V595: The 'oldvdevs' pointer was utilized before it was verified against nullptr. Check lines: 1583, 1595.
In practice, all of these uses were safe because a NULL pointer
implied a 0 vdev count, which kept us from iterating over vdevs.
However, rearranging the code to check the pointer first is not a
terrible micro-optimization and makes it more readable, so let us
do that.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14456
Encrypted blocks can not have 3 DVAs, because they use the space of the
3rd DVA for the IV+salt. zio_write_gang_block() takes this into
account, setting `gbh_copies` to no more than 2 in this case. Gang
members BP's do not have the X (encrypted) bit set (nor do they have the
DMU level and type fields set), because encryption is not handled at
this level. The gang block is reassembled, and then encryption (and
compression) are handled.
To check if this gang block is encrypted, the code in
zio_write_gang_block() checks `pio->io_bp`. This is normally fine,
because the block that's being ganged is typically the encrypted BP.
The problem is that if there is "recursive ganging", where a gang member
is itself a gang block, then when zio_write_gang_block() is called to
create a gang block for a gang member, `pio->io_bp` is the gang member's
BP, which doesn't have the X bit set, so the number of DVA's is not
restricted to 2. It should instead be looking at the the "gang leader",
i.e. the top-level gang block, to determine how many DVA's can be used,
to avoid a "NDVA's inversion" (where a child has more DVA's than its
parent).
gang leader BP: X (encrypted) bit set, 2 DVA's, IV+salt in 3rd DVA's
space:
```
DVA[0]=<1:...:100400> DVA[1]=<0:...:100400> salt=... iv=...
[L0 ZFS plain file] fletcher4 uncompressed encrypted LE
gang unique double size=100000L/100000P birth=... fill=1 cksum=...
```
leader's GBH contains a BP with gang bit set and 3 DVA's:
```
DVA[0]=<1:...:55600> DVA[1]=<0:...:55600>
[L0 unallocated] fletcher4 uncompressed unencrypted LE
contiguous unique double size=55600L/55600P birth=... fill=0 cksum=...
DVA[0]=<1:...:55600> DVA[1]=<0:...:55600>
[L0 unallocated] fletcher4 uncompressed unencrypted LE
contiguous unique double size=55600L/55600P birth=... fill=0 cksum=...
DVA[0]=<1:...:55600> DVA[1]=<0:...:55600> DVA[2]=<1:...:200>
[L0 unallocated] fletcher4 uncompressed unencrypted LE
gang unique double size=55400L/55400P birth=... fill=0 cksum=...
```
On nondebug bits, having the 3rd DVA in the gang block works for the
most part, because it's true that all 3 DVA's are available in the gang
member BP (in the GBH). However, for accounting purposes, gang block
DVA's ASIZE include all the space allocated below them, i.e. the
512-byte gang block header (GBH) as well as the gang members below that.
We see that above where the gang leader BP is 1MB logical (and after
compression: 0x`100000P`), but the ASIZE of each DVA is 2 sectors (1KB)
more than 1MB (0x`100400`).
Since thre are 3 copies of a block below it, we increment the ATIME of
the 3rd DVA of the gang leader by the space used by the 3rd DVA of the
child (1 sector, in this case). But there isn't really a 3rd DVA of the
parent; the salt is stored in place of the 3rd DVA's ASIZE.
So when zio_write_gang_member_ready() increments the parent's BP's
`DVA[2]`'s ASIZE, it's actually incrementing the parent's salt. When we
later try to read the encrypted recursively-ganged block, the salt
doesn't match what we used to write it, so MAC verification fails and we
get an EIO.
```
zio_encrypt(): encrypted 515/2/0/403 salt: 25 25 bb 9d ad d6 cd 89
zio_decrypt(): decrypting 515/2/0/403 salt: 26 25 bb 9d ad d6 cd 89
```
This commit addresses the problem by not increasing the number of copies
of the GBH beyond 2 (even for non-encrypted blocks). This simplifies
the logic while maintaining the ability to traverse all metadata
(including gang blocks) even if one copy is lost. (Note that 3 copies
of the GBH will still be created if requested, e.g. for `copies=3` or
MOS blocks.) Additionally, the code that increments the parent's DVA's
ASIZE is made to check the parent DVA's NDVAS even on nondebug bits. So
if there's a similar bug in the future, it will cause a panic when
trying to write, rather than corrupting the parent BP and causing an
error when reading.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Caused-by: #14356Closes#14440Closes#14413
When testing distributed rebuild performance with more capable
hardware it was observed than increasing the zfs_rebuild_vdev_limit
to 64M reduced the rebuild time by 17%. Beyond 64MB there was
some improvement (~2%) but it was not significant when weighed
against the increased memory usage. Memory usage is capped at 1/4
of arc_c_max.
Additionally, vr_bytes_inflight_max has been moved so it's updated
per-metaslab to allow the size to be adjust while a rebuild is
running.
Reviewed-by: Akash B <akash-b@hpe.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14428
For HDD based pools the default zfs_scan_vdev_limit of 4M
per-vdev can significantly limit the maximum scrub performance.
Increasing the default to 16M can double the scrub speed from
80 MB/s per disk to 160 MB/s per disk.
This does increase the memory footprint during scrub/resilver
but given the performance win this is a reasonable trade off.
Memory usage is capped at 1/4 of arc_c_max. Note that number
of outstanding I/Os has not changed and is still limited by
zfs_vdev_scrub_max_active.
Reviewed-by: Akash B <akash-b@hpe.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14428
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
When resilvering the estimated time remaining is calculated using
the average issue rate over the current pass. Where the current
pass starts when a scan was started, or restarted, if the pool
was exported/imported.
For dRAID pools in particular this can result in wildly optimistic
estimates since the issue rate will be very high while scanning
when non-degraded regions of the pool are scanned. Once repair
I/O starts being issued performance drops to a realistic number
but the estimated performance is still significantly skewed.
To address this we redefine a pass such that it starts after a
scanning phase completes so the issue rate is more reflective of
recent performance. Additionally, the zfs_scan_report_txgs
module option can be set to reset the pass statistics more often.
Reviewed-by: Akash B <akash-b@hpe.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#14410
Despite all optimizations, tests on actual hardware show that FreeBSD
kernel can't sleep for less then ~2us. Similar tests on Linux show
~50us delay at least from nanosleep() (haven't tested inside kernel).
It means that on very fast log device ZIL may not be able to satisfy
zfs_commit_timeout_pct block commit timeout, increasing log latency
more than desired.
Handle that by introduction of zil_min_commit_timeout parameter,
specifying minimal timeout value where additional delays to aggregate
writes may be skipped. Also skip delays if the LWB is more than 7/8
full, that often happens if I/O sizes are constant and match one of
LWB sizes. Both things are applied only if there were no already
outstanding log blocks, that may indicate single-threaded workload,
that by definition can not benefit from the commit delays.
While there, add short time moving average to zl_last_lwb_latency to
make it more stable.
Tests of single-threaded 4KB writes to NVDIMM SLOG on FreeBSD show IOPS
increase by 9% instead of expected 5%. For zfs_commit_timeout_pct of
1 there IOPS increase by 5.5% instead of expected 1%.
Reviewed-by: Allan Jude <allan@klarasystems.com>
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#14418
If we receive a DRR_FREEOBJECTS as the first entry in an object range,
this might end up producing a hole if the freed objects were the
only existing objects in the block.
If the txg starts syncing before we've processed any following
DRR_OBJECT records, this leads to a possible race where the backing
arc_buf_t gets its psize set to 0 in the arc_write_ready() callback
while still being referenced from a dirty record in the open txg.
To prevent this, we insert a txg_wait_synced call if the first
record in the range was a DRR_FREEOBJECTS that actually
resulted in one or more freed objects.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: David Hedberg <david.hedberg@findity.com>
Sponsored by: Findity AB
Closes#11893Closes#14358
In the zstream code, Coverity reported:
"The argument could be controlled by an attacker, who could invoke the
function with arbitrary values (for example, a very high or negative
buffer size)."
It did not report this in the kernel. This is likely because the
userspace code stored this in an int before passing it into the
allocator, while the kernel code stored it in a uint32_t.
However, this did reveal a potentially real problem. On 32-bit systems
and systems with only 4GB of physical memory or less in general, it is
possible to pass a large enough value that the system will hang. Even
worse, on Linux systems, the kernel memory allocator is not able to
support allocations up to the maximum 4GB allocation size that this
allows.
This had already been limited in userspace to 64MB by
`ZFS_SENDRECV_MAX_NVLIST`, but we need a hard limit in the kernel to
protect systems. After some discussion, we settle on 256MB as a hard
upper limit. Attempting to receive a stream that requires more memory
than that will result in E2BIG being returned to user space.
Reported-by: Coverity (CID-1529836)
Reported-by: Coverity (CID-1529837)
Reported-by: Coverity (CID-1529838)
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14285
Introduce four new vdev properties:
checksum_n
checksum_t
io_n
io_t
These properties can be used for configuring the thresholds of zed's
diagnosis engine and are interpeted as <N> events in T <seconds>.
When this property is set to a non-default value on a top-level vdev,
those thresholds will also apply to its leaf vdevs. This behavior can be
overridden by explicitly setting the property on the leaf vdev.
Note that, these properties do not persist across vdev replacement. For
this reason, it is advisable to set the property on the top-level vdev
instead of the leaf vdev.
The default values for zed's diagnosis engine (10 events, 600 seconds)
remains unchanged.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Rob Wing <rob.wing@klarasystems.com>
Sponsored-by: Seagate Technology LLC
Closes#13805
In 2016, the authors of PVS Studio ran it on the FreeBSD kernel, which
identified a number of bugs / cleanup opportunities in the FreeBSD ZFS kernel
code. A few of them persist to the present day:
https://reviews.freebsd.org/D5245
Note that the scan was done against
freebsd/freebsd-src@46763fd4ca.
In particular, we have the following in free_blocks():
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\dnode_sync.c (174): error V547: Expression '__left >= __right' is always true. Unsigned type value is always >= 0.
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\dnode_sync.c (171): error V634: The priority of the '*' operation is higher than that of the '<<' operation. It's possible that parentheses should be used in the expression.
\sys\cddl\contrib\opensolaris\uts\common\fs\zfs\dnode_sync.c (175): error V547: Expression '__left >= __right' is always true. Unsigned type value is always >= 0.
A couple of assertions accidentally typecast the arguments they check to
unsigned in such a way that the result is always true. Also, parentheses
are missing around `1<<epbs` in `(db->db_blkid * 1<<epbs)`. This works
out to be okay due to multiplication not caring what order of operations
we use, but it is better to fix it to be `(db->db_blkid << epbs)`.
A few of the function local variables probably never should have been
32-bit in the first place, so we make them 64-bit. We also replace the
existing assertions with additional assertions to ensure that 64-bit
unsigned arithmetic is safe.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14407
When zfs_file_read returns error, resid may be uninitialized.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes#14404
This is only ever used with unsigned data, so the type itself should be
unsigned. Also, PVS Studio's 2016 FreeBSD kernel report correctly
identified the following assertion as always being true, so we can drop
it:
ASSERT3U(dd->dd_space_towrite[i & TXG_MASK], >=, 0);
The reason it was always true is because it would do casts to give us
unsigned comparisons. This could have been fixed by switching to
`ASSERT3S()`, but upon inspection, it turned out that this variable
never should have been allowed to be signed in the first place.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14408
Use the saved property index instead of looking it up once per DSL
directory when traversing up towards the root.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Sponsored-by: The FreeBSD Foundation
Closes#14397
Reported-by: KMSAN
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Reviewed-by: Akash B <akash-b@hpe.com>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Sponsored-by: The FreeBSD Foundation
Closes#14397
I recently gained the ability to run Clang's static analyzer on the
linux kernel modules via a few hacks. This extended coverage to code
that was previously missed since Clang's static analyzer only looked at
code that we built in userspace. Running it against the Linux kernel
modules built from my local branch produced a total of 72 reports
against my local branch. Of those, 50 were reports of logic errors and
22 were reports of dead code. Since we already had cleaned up all of
the previous dead code reports, I felt it would be a good next step to
clean up these dead code reports. Clang did a further breakdown of the
dead code reports into:
Dead assignment 15
Dead increment 2
Dead nested assignment 5
The benefit of cleaning these up, especially in the case of dead nested
assignment, is that they can expose places where our error handling is
incorrect. A number of them were fairly straight forward. However
several were not:
In vdev_disk_physio_completion(), not only were we not using the return
value from the static function vdev_disk_dio_put(), but nothing used it,
so I changed it to return void and removed the existing (void) cast in
the other area where we call it in addition to no longer storing it to a
stack value.
In FSE_createDTable(), the function is dead code. Its helper function
FSE_freeDTable() is also dead code, as are the CPP definitions in
`module/zstd/include/zstd_compat_wrapper.h`. We just delete it all.
In zfs_zevent_wait(), we have an optimization opportunity. cv_wait_sig()
returns 0 if there are waiting signals and 1 if there are none. The
Linux SPL version literally returns `signal_pending(current) ? 0 : 1)`
and FreeBSD implements the same semantics, we can just do
`!cv_wait_sig()` in place of `signal_pending(current)` to avoid
unnecessarily calling it again.
zfs_setattr() on FreeBSD version did not have error handling issue
because the code was removed entirely from FreeBSD version. The error is
from updating the attribute directory's files. After some thought, I
decided to propapage errors on it to userspace.
In zfs_secpolicy_tmp_snapshot(), we ignore a lack of permission from the
first check in favor of checking three other permissions. I assume this
is intentional.
In zfs_create_fs(), the return value of zap_update() was not checked
despite setting an important version number. I see no backward
compatibility reason to permit failures, so we add an assertion to catch
failures. Interestingly, Linux is still using ASSERT(error == 0) from
OpenSolaris while FreeBSD has switched to the improved ASSERT0(error)
from illumos, although illumos has yet to adopt it here. ASSERT(error ==
0) was used on Linux while ASSERT0(error) was used on FreeBSD since the
entire file needs conversion and that should be the subject of
another patch.
dnode_move()'s issue was caused by us not having implemented
POINTER_IS_VALID() on Linux. We have a stub in
`include/os/linux/spl/sys/kmem_cache.h` for it, when it really should be
in `include/os/linux/spl/sys/kmem.h` to be consistent with
Illumos/OpenSolaris. FreeBSD put both `POINTER_IS_VALID()` and
`POINTER_INVALIDATE()` in `include/os/freebsd/spl/sys/kmem.h`, so we
copy what it did.
Whenever a report was in platform-specific code, I checked the FreeBSD
version to see if it also applied to FreeBSD, but it was only relevant a
few times.
Lastly, the patch that enabled Clang's static analyzer to be run on the
Linux kernel modules needs more work before it can be put into a PR. I
plan to do that in the future as part of the on-going static analysis
work that I am doing.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14380
There is an external assembly declaration extension in GNU C that glibc
uses when building with ieee128 floating point support on ppc64le.
Marking that as volatile makes no sense, so the build breaks.
It does not make sense to only mark this as volatile on Linux, since if
do not want the compiler reordering things on Linux, we do not want the
compiler reordering things on any other platform, so we stop treating
Linux specially and just manually inline the CPP macro so that we can
eliminate it. This should fix the build on ppc64le.
Tested-by: @gyakovlev
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14308Closes#14384
