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
Unfortunately, even after e79b6807, I still, much more rarely,
tripped asserts when playing with many ctldir mounts at once.
Since this appears to happen if we dispatched twice too fast, just
ignore it. We don't actually need to do anything if someone already
started doing it for us.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes#14462
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
We've had cases where we trigger an OOM despite having memory freely
available on the system. For example, here, we had about 21GB free:
kernel: Node 0 Normal: 2418758*4kB (UME) 1549533*8kB (UE) 0*16kB
0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB =
22071296kB
The problem being, all the memory is in 4K and 8K contiguous regions,
but the allocation request was for a 16K contiguous region:
kernel: SafeExecutors-4 invoked oom-killer:
gfp_mask=0x42dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO),
order=2, oom_score_adj=0
The offending allocation came from this call trace:
kernel: Call Trace:
kernel: dump_stack+0x57/0x7a
kernel: dump_header+0x4f/0x1e1
kernel: oom_kill_process.cold.33+0xb/0x10
kernel: out_of_memory+0x1ad/0x490
kernel: __alloc_pages_slowpath+0xd55/0xe40
kernel: __alloc_pages_nodemask+0x2df/0x330
kernel: kmalloc_large_node+0x42/0x90
kernel: __kmalloc_node+0x25a/0x320
kernel: ? spl_kmem_free_impl+0x21/0x30 [spl]
kernel: spl_kmem_alloc_impl+0xa5/0x100 [spl]
kernel: spl_kmem_zalloc+0x19/0x20 [spl]
kernel: zfsdev_ioctl+0x2b/0xe0 [zfs]
kernel: do_vfs_ioctl+0xa9/0x640
kernel: ? __audit_syscall_entry+0xdd/0x130
kernel: ksys_ioctl+0x67/0x90
kernel: __x64_sys_ioctl+0x1a/0x20
kernel: do_syscall_64+0x5e/0x200
kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9
kernel: RIP: 0033:0x7fdca3674317
The problem is, for each ioctl that ZFS makes, it has to allocate a
zfs_cmd_t structure, which is 13744 bytes in size (on my system):
sdb> sizeof zfs_cmd
(size_t)13744
This size, coupled with the fact that we currently allocate it with
kmem_zalloc, means we need a 16K contiguous region of memory to satisfy
the request.
The solution taken by this change, is to use "vmem" instead of "kmem" to
do the allocation, such that we don't necessarily need a contiguous 16K
memory region to satisfy the allocation.
Arguably, a better solution would be not to require such a large
allocation to begin with (e.g. reduce the size of the zfs_cmd_t
structure), but that'd be a much larger change than this "one liner".
Thus, I've opted for this approach for now; we can always circle back
and attempt to reduce the size of the structure in the future.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes#14474
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
Clang's static analyzer pointed out that if alloc_pages >= nr_pages
before the loop, the value of page will be undefined and will be used
anyway. This should not be possible, but as cleanup, we add an
assertion. We also recognize that the local variables should be unsigned
in the first place, so we make them unsigned. This is not enough to
avoid the need for the assertion, since there is still the case that
alloc_pages == nr_pages and nr_pages == 0, which the assertion
implicitly checks.
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
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
`dsl_dir_activity_in_progress()` can call `zfs_get_temporary_prop()` with
the forth value set to NULL, which will pass NULL to `strcpy()` when
there is a match
Clang's static analyzer caught this with the help of CodeChecker for
Cross Translation Unit analysis.
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
The remaining changes needed to make the assembly files work
with macOS.
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#14451
Pull in d40f55cd950919d7eac951b122668e55e33e5202 from upstream
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes#14439
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
Linux 6.2 changes the second argument of the set_acl operation to be a
"struct dentry *" rather than a "struct inode *". The inode* parameter
is still available as dentry->d_inode, so adjust the call to the _impl
function call to dereference and pass that pointer to it.
Also document that the get_acl -> get_inode_acl member name change from
commit 884a693 was an API change also introduced in Linux 6.2.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes#14415
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
The .align directive used to align storage locations is
ambiguous. On some platforms and assemblers it takes a byte count,
on others the argument is interpreted as a shift value. The current
usage expects the first interpretation.
Replace it with the unambiguous .balign directive which always
expects a byte count, regardless of platform and assembler.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#14422
The .size directive used by the SET_SIZE C macro uses the special
dot symbol to calculate the size of a function. The dot symbol
refers to the current address, so for the calculation to be
meaningful the SET_SIZE macro must be placed immediately after the
end of the function the size is calculated for.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes#14422
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
In original code, zfs_znode_dmu_fini is called in zfs_rmnode without
zfs_znode_hold_enter. It seems to assume it's ok to do so when the znode
is unlinked. However this assumption is not correct, as zfs_zget can be
called by NFS through zpl_fh_to_dentry as pointed out by Christian in
https://github.com/openzfs/zfs/pull/12767, which could result in a
use-after-free bug.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#12767Closes#14364
Add new macro ASMABI used by Windows to change
calling API to "sysv_abi".
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes#14228
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
