sites and installing a hook at the kernel's trap handler. The fasttrap code
will emulate the overwritten instruction in some common cases, but otherwise
copies it out into some scratch space in the traced process' address space
and ensures that it's executed after returning from the trap.
In Solaris and illumos, this (per-thread) scratch space comes from some
reserved space in TLS, accessible via the fs segment register. This
approach is somewhat unappealing on FreeBSD since it would require some
modifications to rtld and jemalloc (for static TLS) to ensure that TLS is
executable, and would thus introduce dependencies on their implementation
details. I think it would also be impossible to safely trace static binaries
compiled without these modifications.
This change implements the functionality in a different way, by having
fasttrap map pages into the target process' address space on demand. Each
page is divided into 64-byte chunks for use by individual threads, and
fasttrap's process descriptor struct has been extended to keep track of
any scratch space allocated for the corresponding process.
With this change it's possible to trace all libc functions in a program,
e.g. with
pid$target:libc.so.*::entry {@[probefunc] = count();}
Previously this would generally cause the victim process to crash, as
tracing memcpy on amd64 requires the functionality described above.
Tested by: Prashanth Kumar <pra_udupi@yahoo.co.in> (earlier version)
MFC after: 6 weeks
this is due to a wrong dereference of a vnode when it's not locked and
can be (potentially) recycled. 'sdvp' cannot be locked on zfs_rename()
entry point because the VFS can't be sure that this scenario is
LOR-free (it might violate the parent->child lock acquisition rule).
Dereference 'tdvp' instead, which is already locked on entry, and access
'sdvp' fields only when it's safe, i.e. under ZFS_ENTER scope.
While at it, remove the usage of VOP_REALVP, as long as this is a NOP
on FreeBSD.
Discussed with: avg
Reviewed by: pjd
New ZFS property volmode and sysctl vfs.zfs.vol.mode allow switching ZVOL
between three modes:
geom -- existing fully functional behavior (default);
dev -- exposing volumes only as raw disk device file in devfs;
none -- not exposing volumes outside ZFS.
The "dev" mode is less functional (can't be partitioned, mounted, etc),
but it is faster, and in some scenarios with untrusted consumers safer.
It can be useful for NAS, VM block storages, etc.
The "none" mode may be convenient for backup servers, etc. that don't
need direct data access.
Due to the way ZVOL is integrated with main ZFS code, those property
and sysctl are checked only during pool import and volume creation.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
3580 Want zvols to return volblocksize when queried for physical block size
illumos/illumos-gate@a0b60564df
It is irrelevant for FreeBSD, just reducing diff.
It is an adapted merge from the vendor branch of:
701 UNMAP support for COMSTAR (in part related to ZFS)
2130 zvol DKIOCFREE uses nested DMU transactions
4248 dtrace(1M) should never create DOF with empty probes section
4249 Only probes from the first DTrace object file will be included
Illumos Revision: 4a20ab41aadcb81c53e72fc65886e964e9add59
Reference:
https://www.illumos.org/issues/4248https://www.illumos.org/issues/4249
Obtained from: Illumos
MFC after: 1 month
To reduce the diff struct pcu.cnt field was not renamed, so
PCPU_OP(cnt.field) is still used. pc_cnt and pcpu are also used in
kvm(3) and vmstat(8). The goal was to not affect externally used KPI.
Bump __FreeBSD_version_ in case some out-of-tree module/code relies on the
the global cnt variable.
Exp-run revealed no ports using it directly.
No objection from: arch@
Sponsored by: EMC / Isilon Storage Division
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.
MFC after: 3 weeks
so there is no reason to assert that we won't hit an error. Instead,
just return that error to caller and have the upper layer handle it.
Obtained from: FreeNAS
Reported by: rodrigc
Reviewed by: Matthew Ahrens
MFC after: 2 weeks
that this is done for SDT probes. This fixes the syscall/tst.args.d test,
which was failing because mmap(2)'s sixth argument wasn't available to the
probe.
MFC after: 2 weeks
illumos/illumos-gate@6fb4854bed
This fixes the tst.resize1.d and tst.resize2.d DTrace tests, which have
been failing since r261122 since they were causing dtrace(1) to attempt to
allocate and use large amounts of memory, and get killed by the OOM killer
as a result.
MFC after: 1 month
upstream DTrace code. It indicates that the kernel memory allocator need not
attempt to satisfy non-blocking allocations in low-memory conditions. This
has no direct equivalent in the malloc(9) flags, so it is just defined to 0
for now.
4574 get_clones_stat does not call zap_count in non-debug kernel
zap_count(...) is never called in non-DEBUG kernel.
As result "count" variable is always 0, and "goto fail" is always
reached. This means get_clones_stat function never makes up list
of clones for "clones" properties.
MFC after: 2 weeks
This is done to ensure that visited object IDs are always increasing.
Also, pass correct object ID to prefetch_dnode_metadata for
os_groupused_dnode.
Without this change we would hit an assert if traversal was paused on
a GROUPUSED object, which is unlikely but possible.
Apparently the same change was independently developed by Deplhix.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
MFC after: 10 days
Sponsored by: HybridCluster
The bug was introduced in r256956 "Improve ZFS N-way mirror read
performance".
The code in vdev_mirror_dva_select erroneously considers already
tried DVAs for the next attempt. Thus, it is possible that a failing DVA
would be retried forever.
As a secondary effect, if the attempts fail with checksum error, then
checksum error reports are accumulated until the original request
ultimately fails or succeeds. But because retrying is going on indefinitely
the cheksum reports accumulation will effectively be a memory leak.
Reviewed by: gibbs
MFC after: 13 days
Sponsored by: HybridCluster
If we prematurely free the name buffer and it gets quickly recycled,
then zfs_rename may see data from another lookup or even unmapped memory
via cn_nameptr.
MFC after: 6 days
Sponsored by: HybridCluster
The bug was introduced in r256956 "Improve ZFS N-way mirror read
performance".
The code in vdev_mirror_dva_select erroneously considers already
tried DVAs for the next attempt. Thus, it is possible that a failing DVA
would be retried forever.
As a secondary effect, if the attempts fail with checksum error, then
checksum error reports are accumulated until the original request
ultimately fails or succeeds. But because retrying is going on indefinitely
the cheksum reports accumulation will effectively be a memory leak.
Reviewed by: gibbs
MFC after: 13 days
Sponsored by: HybridCluster
Otherwise we could run into the following deadlock.
A thread has a transaction open and assigned to a transaction group.
That would prevent the transaction group from be quiesced and synced.
The thread is blocked in getnewvnode_reserve waiting for a vnode to
a be reclaimed. vnlru thread is blocked trying to enter ZFS VOP because
a filesystem is suspended by an ongoing rollback or receive operation.
In its turn the operation is waiting for the current transaction group
to be synced.
zfs_zget is always used outside of active transactions, but zfs_mknode
is always used in a transaction context. Thus, we hoist
getnewvnode_reserve from zfs_mknode to its callers.
While there, assert that ZFS always calls getnewvnode while having
a vnode reserved.
Reported by: adrian
Tested by: adrian
MFC after: 17 days
Sponsored by: HybridCluster
When we encounter an I/O error on a piece of metadata while deleting
a file system or zvol, we don't update the bptree_entry_phys_t's
bookmark. This would lead to double free of bp's which will lead to
space map corruption.
Instead of tolerating and allowing the corruption, panic immediately.
See Illumos #4390 for more details.
4391 panic system rather than corrupting pool if we hit bug 4390
Illumos/illumos-gate@8b36997aa2
MFC after: 2 weeks
4370 avoid transmitting holes during zfs send
4371 DMU code clean up
illumos/illumos-gate@43466aae47
NOTE: Make sure the boot code is updated if a zpool upgrade is
done on boot zpool.
MFC after: 2 weeks
(Note: this change is not applicable to FreeBSD and the file
is not included in build. It's integrated for completeness).
4128 disks in zpools never go away when pulled
illumos/illumos-gate@39cddb10a3
MFC after: 2 weeks
3306 zdb should be able to issue reads in parallel
3321 'zpool reopen' command should be documented in the man page
and help message
illumos/illumos-gate@31d7e8fa33
FreeBSD porting notes: the kernel part of this changeset depends
on Solaris buf(9S) interfaces and are not really applicable for
our use. vdev_disk.c is patched as-is to reduce diverge from
upstream, but vdev_file.c is left intact.
MFC after: 2 weeks
aggregation IDs, as is done in the upstream illumos code. This still
requires some FreeBSD-specific code, as our vmem API is not identical to the
one in illumos.
Submitted by: Mike Ma <mikemandarine@gmail.com>
4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool
features
illumos/illumos-gate@2acef22db7
MFC after: 2 weeks
4168 ztest assertion failure in dbuf_undirty
4169 verbatim import causes zdb to segfa
4170 zhack leaves pool in ACTIVE state
illumos/illumos-gate@7fdd916c47
MFC after: 2 weeks
