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
This has been filed as llvm/llvm-project#60694. Switching from a copy
through a C pointer dereference to an explicit memcpy() is a workaround
that prevents a false positive.
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
gmac_init_ctx() duplicates most of the code in gcm_int_ctx() while
it just needs to set its own IV length and AAD tag length.
Introduce gcm_init_ctx_impl() which handles the GCM and GMAC
differences while reusing the duplicated code.
While here, fix a flaw where the AVX implementation would accept a
context using a byte swapped key schedule which it could not
handle. Also constify the IV and AAD pointers passed to
gcm_init{,_avx}().
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#14529
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
The assert is enabled when DEBUG_VFS_LOCKS kernel option is set.
The exact panic is:
panic: condition seqc_in_modify(_vp->v_seqc) not met
It happens because seqc protocol is not followed for ZIL replay.
But we actually do not need to make any namecache calls at that stage,
because the namecache use is not enabled until after the replay is
completed.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Closes#14566
An IBM POWER7 system with Power ISA 2.06 tried to execute
zfs_sha256_power8() - which should only be run on ISA 2.07
machines.
The detection is implemented via the zfs_isa207_available() call,
but this check was not used.
This pull request will fix this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Low-power <msl0000023508@gmail.com>
Closes#14576
This is needed because of a possible error path where zfs_vnode_forget()
is called. That function calls vgone() and vput(), the former requires
the vnode to be exclusively locked and the latter expects it to be
locked.
It should be safe to lock the vnode as early as possible because it is
not yet visible, so there is no interaction with other locks.
While here, remove a tautological assignment to 'vp'.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Closes#14565
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 recent 4c5fec01a4 commit caused
Coverity to report that ASSERT3U(algotype, >=, SHA256_MECH_INFO_TYPE);
is always true. That is because the signed algotype and signed
SHA256_MECH_INFO_TYPE values were cast to unsigned types. To fix this,
we switch the assertions to use ASSERT3S(), which retains the signedness
of the original values for the comparison.
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>
Reported-by: Coverity (CID-1535300)
Closes#14573
Make sure all SHA2 transform function has wrappers
For ASMABI to work, it is required the calling convention
is consistent.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Joergen Lundman <lundman@lundman.net>
Closes#14569
- instead of ".section .rodata" we should use SECTION_STATIC
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
This commit changes the BLAKE3 implementation handling and
also the calls to it from the ztest command.
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
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
We had three sha2.h headers in different places.
The FreeBSD version, the Linux version and the generic solaris version.
The only assembly used for acceleration was some old x86-64 openssl
implementation for sha256 within the icp module.
For FreeBSD the whole SHA2 files of FreeBSD were copied into OpenZFS,
these files got removed also.
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
After 89cd2197b9 was merged, Clang's
static analyzer began complaining about a dead assignment in
`zfs_fillpage()`. Upon inspection, I noticed that the dead assignment
was because we are not using the calculated io_len that we should use to
avoid asking the DMU to read past the end of a file. This should result
in `dmu_buf_hold_array_by_dnode()` calling `zfs_panic_recover()`.
This issue predates 89cd2197b9, but its
simplification of zfs_fillpage() eliminated the only use of the
assignment to io_len, which made Clang's static analyzer complain about
the issue.
Also, as a precaution, we add an assertion that io_offset < i_size. If
this ever fails, bad things will happen. Otherwise, we are blindly
trusting the kernel not to give us invalid offsets. We continue to
blindly trust it on non-debug kernels.
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#14534
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
xxhash.c was not being compiled, so when FreeBSD's kernel
switched to a newer version of ZSTD a few weeks ago, out-of-tree ZFS
failed to build
Sync module/Makefile.bsd with FreeBSD's sys/modules/zfs/Makefile
And restore the alphabetical sort in a number of places
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Sponsored-by: Klara, Inc.
Closes#14508
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
The recently merged f58e513f74 was
intended to zero sensitive data before exit from encryption
functions to harden the code against theoretical information
leaks. Unfortunately, the method by which it did that is
optimized away by the compiler, so some information still leaks. This
was confirmed by counting function calls in disassembly.
After studying how the OpenBSD, FreeBSD and Linux kernels handle this,
and looking at our disassembly, I decided on a two-factor approach to
protect us from compiler dead store elimination passes.
The first factor is to stop trying to inline gcm_clear_ctx(). GCC does
not actually inline it in the first place, and testing suggests that
dead store elimination passes appear to become more powerful in a bad
way when inlining is forced, so we recognize that and move
gcm_clear_ctx() to a C file.
The second factor is to implement an explicit_memset() function based on
the technique used by `secure_zero_memory()` in FreeBSD's blake2
implementation, which coincidentally is functionally identical to the
one used by Linux. The source for this appears to be a LLVM bug:
https://llvm.org/bugs/show_bug.cgi?id=15495
Unlike both FreeBSD and Linux, we explicitly avoid the inline keyword,
based on my observations that GCC's dead store elimination pass becomes
more powerful when inlining is forced, under the assumption that it will
be equally powerful when the compiler does decide to inline function
calls.
Disassembly of GCC's output confirms that all 6 memset() calls are
executed with this patch applied.
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#14544
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
During a mount, zpl_mount_impl(), uses sget() with the callback
zpl_test_super() to find a super_block with a matching objset,
stored in z_os. It does so without taking the teardown lock on
the zfsvfs.
The problem is that operations like rollback will replace the
z_os. And, there is a window where the objset in the rollback
is freed, but z_os still points to it. Then, a mount like
operation, for instance a clone, can reallocate that exact same
pointer and zpl_test_super() will then match the super_block
associated with the rollback as opposed to the clone.
This fix tests for a match and if so, takes the teardown lock
before doing the final match test.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Poduska <jpoduska@datto.com>
Closes#14518
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
Currently the temporary buffer in which decryption takes place
isn't cleared on context destruction. Further in some routines we
fail to call gcm_clear_ctx() on error exit. Both flaws may result
in leaking sensitive data.
We follow best practices and zero out the plaintext buffer before
freeing the memory holding it. Also move all cleanup into
gcm_clear_ctx() and call it on any context destruction.
The performance impact should be negligible.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#14528
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
When a page is faulted in for memory mapped I/O the page lock
may be dropped before it has been read and marked up to date.
If a buffered read encounters such a page in mappedread() it
must wait until the page has been updated. Failure to do so
will result in a panic on debug builds and incorrect data on
production builds.
The critical part of this change is in mappedread() where pages
which are not up to date are now handled. Additionally, it
includes the following simplifications.
- zfs_getpage() and zfs_fillpage() could be passed an array of
pages. This could be more efficient if it was used but in
practice only a single page was ever provided. These
interfaces were simplified to acknowledge that.
- update_pages() was modified to correctly set the PG_error bit
on a page when it cannot be read by dmu_read().
- Setting PG_error and PG_uptodate was moved to zfs_fillpage()
from zpl_readpage_common(). This is consistent with the
handling in update_pages() and mappedread().
- Minor additional refactoring to comments and variable
declarations to improve readability.
- Add a test case to exercise concurrent buffered, direct,
and mmap IO to the same file.
- Reduce the mmap_sync test case default run time.
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13608Closes#14498
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
Under certain loads, the following panic is hit:
panic: page fault
KDB: stack backtrace:
#0 0xffffffff805db025 at kdb_backtrace+0x65
#1 0xffffffff8058e86f at vpanic+0x17f
#2 0xffffffff8058e6e3 at panic+0x43
#3 0xffffffff808adc15 at trap_fatal+0x385
#4 0xffffffff808adc6f at trap_pfault+0x4f
#5 0xffffffff80886da8 at calltrap+0x8
#6 0xffffffff80669186 at vgonel+0x186
#7 0xffffffff80669841 at vgone+0x31
#8 0xffffffff8065806d at vfs_hash_insert+0x26d
#9 0xffffffff81a39069 at sfs_vgetx+0x149
#10 0xffffffff81a39c54 at zfsctl_snapdir_lookup+0x1e4
#11 0xffffffff8065a28c at lookup+0x45c
#12 0xffffffff806594b9 at namei+0x259
#13 0xffffffff80676a33 at kern_statat+0xf3
#14 0xffffffff8067712f at sys_fstatat+0x2f
#15 0xffffffff808ae50c at amd64_syscall+0x10c
#16 0xffffffff808876bb at fast_syscall_common+0xf8
The page fault occurs because vgonel() will call VOP_CLOSE() for active
vnodes. For this reason, define vop_close for zfsctl_ops_snapshot. While
here, define vop_open for consistency.
After adding the necessary vop, the bug progresses to the following
panic:
panic: VERIFY3(vrecycle(vp) == 1) failed (0 == 1)
cpuid = 17
KDB: stack backtrace:
#0 0xffffffff805e29c5 at kdb_backtrace+0x65
#1 0xffffffff8059620f at vpanic+0x17f
#2 0xffffffff81a27f4a at spl_panic+0x3a
#3 0xffffffff81a3a4d0 at zfsctl_snapshot_inactive+0x40
#4 0xffffffff8066fdee at vinactivef+0xde
#5 0xffffffff80670b8a at vgonel+0x1ea
#6 0xffffffff806711e1 at vgone+0x31
#7 0xffffffff8065fa0d at vfs_hash_insert+0x26d
#8 0xffffffff81a39069 at sfs_vgetx+0x149
#9 0xffffffff81a39c54 at zfsctl_snapdir_lookup+0x1e4
#10 0xffffffff80661c2c at lookup+0x45c
#11 0xffffffff80660e59 at namei+0x259
#12 0xffffffff8067e3d3 at kern_statat+0xf3
#13 0xffffffff8067eacf at sys_fstatat+0x2f
#14 0xffffffff808b5ecc at amd64_syscall+0x10c
#15 0xffffffff8088f07b at fast_syscall_common+0xf8
This is caused by a race condition that can occur when allocating a new
vnode and adding that vnode to the vfs hash. If the newly created vnode
loses the race when being inserted into the vfs hash, it will not be
recycled as its usecount is greater than zero, hitting the above
assertion.
Fix this by dropping the assertion.
FreeBSD-issue: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=252700
Reviewed-by: Andriy Gapon <avg@FreeBSD.org>
Reviewed-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Alek Pinchuk <apinchuk@axcient.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Rob Wing <rob.wing@klarasystems.com>
Co-authored-by: Rob Wing <rob.wing@klarasystems.com>
Submitted-by: Klara, Inc.
Sponsored-by: rsync.net
Closes#14501
When jail.conf set the nopersist flag during startup, it was
incorrectly destroying the per-jail ZFS settings.
Reported-by: Martin Matuska <mm@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Sponsored-by: Modirum MDPay
Sponsored-by: Klara, Inc.
Closes#14509
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
