Reviewed by: Bayard Bell <buffer.g.overflow@gmail.com>
Reviewed by: Alek Pinchuk <alek@nexenta.com>
Reviewed by: Simon Klinkert <simon.klinkert@gmail.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Matthew Ahrens <mahrens@delphix.com>
illumos/illumos-gate@46e1baa6cfhttps://www.illumos.org/issues/5911
Sometimes ZFS appears to hang while deleting a file. It is actually
making slow progress at the file deletion, but other operations
(administrative and writes via the data path) "hang" until the file
removal completes, which can take a long time if the file has many
blocks. The deletion (or most of it) happens in a single txg, and the
sync thread spends most of its time reading indirect blocks via this
stack trace:
swtch+0x141()
cv_wait+0x70()
zio_wait+0x5b()
dbuf_read+0x2c0()
free_children+0x50()
free_children+0x12a()
free_children+0x12a()
free_children+0x12a()
dnode_sync_free_range_impl+0xdf()
dnode_sync_free_range+0x52()
range_tree_vacate+0x65()
dnode_sync+0x1d8()
dmu_objset_sync_dnodes+0x77()
dmu_objset_sync+0x19f()
dsl_dataset_sync+0x51()
dsl_pool_sync+0x9a()
spa_sync+0x2ff()
txg_sync_thread+0x21f()
thread_start+8()
One way to reproduce the problem is if we are over the arc_meta_limit,
e.g. because lots of indirect blocks are pinned because we have L0
dbufs under them. It could be that most of the L1 indirects are cached,
in which case when dmu_free_long_range_impl() calls dmu_tx_hold_free(),
it will complete very quickly. This allows dmu_free_long_range_impl() to
put many (perhaps all of its) transactions in the same TXG. However,
dmu_free_long_range_impl() calls dnode_evict_dbufs (and
dnode_free_range()), which removes the L0 dbufs, thus reducing the hold
count on the L1 indirect blocks above it, allowing them to be evicted.
Because we are over the arc_meta_limit(), these L1 blocks will be
evicted ASAP. Thus when we get to syncing context, the L1 indirects are
no longer cached and must be read in.
Obtained from: illumos
MFC after: 15 days
Do that only when when fast inline versions are available.
At the moment that can be the case only in the kernel and not for all
platforms.
The original code uses the binary search and that's kept as a fallback.
This is a micro optimization.
Differential Revision: https://reviews.freebsd.org/D2839
Reviewed by: delphij, mahrens, mav
MFC after: 17 days
o Provide an extensive set of assertions for input array of pages.
o Remove now duplicate assertions from different pagers.
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
The problem is that when inline versions of flsl and flsll are not
available, then libkern.h must be included for their declarations
in kernel sources.
The fix would be trivial, but I would like to figure out first if
it even makes sense to use the libkern provided implementations.
Reported by: bz
Pointyhat to: avg
b_size is a logical size of a buffer in memory, b_asize is its physical
size that accounts for possible compression.
Currently the latter is the best approximation for the allocated, on-disk
size.
L2ARC TRIM support was committed a few weeks before L2ARC compression
was imported, so originally the code was correct, because b_size was
the size.
Further thoughts. Given that the cache device is being overwritten
in a circular fashion it is not clear if a TRIM per each evicted L2ARC
buffer has any benefits.
Maybe it would be sufficient to issue a single trim request for the whole
device when it is loaded, e.g. after a bootup, or when it is unloaded, e.g.
before a shutdown. At least as long as L2ARC is not persistent across
reboots.
Discussed with: smh
MFC after: 19 says
This is a micro optimization.
The upstream code uses the binary search.
Differential Revision: https://reviews.freebsd.org/D2839
Reviewed by: delphij, mav
MFC after: 15 days
5946 zfs_ioc_space_snaps must check that firstsnap and lastsnap refer to snapshots
5945 zfs_ioc_send_space must ensure that fromsnap refers to a snapshot
Reviewed by: Steven Hartland <killing@multiplay.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Gordon Ross <gordon.ross@nexenta.com>
illumos/illumos-gate@24218bebb4
Note that the upstream commit is modified during MFV: in the upstream
the check is done by inspecting ds_is_snapshot field while in FreeBSD
we call dsl_dataset_is_snapshot().
This is because illumos/illumos-gate@bc9014e6a8
(r277428 in vendor-sys/illumos) is not MFV-ed yet.
MFC after: 10 days
Currently there is no good reason to mangle the userland API.
The change was introduced in eac1d566b4,
r279437. Also see https://reviews.freebsd.org/D1881.
I am still convinced that nv should not have introduced intentionally
conflicting API.
Discussed with: rstone
X-MFC with: r279437
Sponsored by: ClusterHQ
Nothing stops a parallel unmount to suceed before the given call to
dounmount() checks and locks the covered vnode. Prevent dounmount()
from acting on the freed (although type-stable) memory by changing the
interface to require the mount point to be referenced. dounmount()
consumes the reference on return, regardless of the sucessfull or
erronous result.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
- this should fail early unless the force flag is set
- if the force flag is set then any local modifications including
snapshots should be undone
See: https://www.illumos.org/issues/5912
See: https://reviews.csiden.org/r/220/
Reviewed by: mahrens, Paul Dagnelie <pcd@delphix.com>
MFC after: 15 days
Sponsored by: ClusterHQ
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
This allows to ensure that we do not write to a file that was opened
for reading only or vice versa.
Also, use the correct capability in in zfs_ioc_send_new().
Differential Revision: https://reviews.freebsd.org/D2382
Reviewed by: delphij
MFC after: 17 days
Sponsored by: ClusterHQ
At present zfs_domount() acquires a reference on the filesystem's root vnode
and that reference is kept until zfs_umount.
The latter calls vflush(rootrefs = 1) to dispose of the extra reference.
There is no explanation of why that reference is kept - what problem it
solves or what behavior it improves.
Also, that logic is FreeBSD specific.
There is one real problem with that reference, though.
zfs recv -F may receive a full, non-incremental stream to a mounted filesystem.
In that case the received root object is likely to have a different z_gen
attribute value. Because of that, zfs_rezget will leave the previous root znode
and vnode disassociated from the actual object (z_sa_hdl == NULL).
Thus, future calls to VFS_ROOT() -> zfs_root() will produce a new vnode-znode
pair, while the old one will be kept alive by the outstanding reference.
So, the outstanding reference will not actually be for the new root vnode
(or, more precisely, vnodes - because a root vnode may be recycled and a newer
one can be created).
As a result, when vflush(rootrefs = 1) s called there will be two problems:
- a leaked reference on the old root vnode preventing a graceful unmount
- insufficient references on the actual root vnode leading to a crash upon
access to the vnode after it is destroyed by vgone() + vdrop()
The second issue will actually override the first one.
Differential Revision: https://reviews.freebsd.org/D2353
Reviewed by: delphij, kib, smh
MFC after: 17 days
In traverse_visitbp(), the input argument dnp is modified in the middle
to point to a temporary buffer. Originally this doesn't matter, because
no user of TRAVERSE_POST dereferences it. However, in fbeddd6 a piece of
code is added dereferencing dnp after the modification, creating a possible
bug.
We fix this by creating a new local variable cdnp for the DMU_OT_DNODE case,
so we don't modify the input argument. Also we introduce different local
variables in the DMU_OT_OBJSET case to prevent confusion between the input
argument.
Obtained from: zfsonlinux (a585f2f844ed3d4270221fed88f5e494eb55d932)
MFC after: 2 weeks
Sponsored by: Multiplay
The old comment in zfs_rezget explains what situation the code handles,
the new comment also describes how the situation can arise.
Also, re-join a line that became sufficiently shorti some time ago.
Differential Revision: https://reviews.freebsd.org/D2352
Reviewed by: delphij, smh
MFC after: 12 days
/dev/zfs always has per-open data, so when it is missing the file
descriptor is for some other file. Returning ENOENT in this case
is confusing as a variety of other conditions (like a missing dataset)
may result in the same error. It's better to consistently return
EBADF for any problems with the file descriptor.
Note that zfs_onexit_fd_hold() is used with 'automatic cleanup fd'
- when that fd is closed, typically because a process is terminated,
some cleanup action is taken by ZFS driver. E.g. a temporary
snapshot hold is released.
Perhaps, it would even be worthwhile changing devfs_get_cdevpriv()
to return EBADF if there is no associated data.
Differential Revision: https://reviews.freebsd.org/D2370
Reviewed by: delphij, smh
MFC after: 12 days
skip 10, rather than 9, frames. This appears to work quite well in
practice on the BeagleBone Black, so remove a comment about the value
being bogus and replace it with a slightly less negative one. However,
the number of frames to skip is quite sensitive to details of the timer
and interrupt handling paths, so this is necessarily fragile -- but no
more so than on x86.
Sponsored by: DARPA, AFRL
It would previously call into some unfinished Solaris compatibility code and
return without actually calling panic(9). The compatibility code is
unneeded, however, so just remove it and have dtrace_panic() call vpanic(9)
directly.
Differential Revision: https://reviews.freebsd.org/D2349
Reviewed by: avg
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
Passing "-x lazyload" to dtrace -G during compilation causes dtrace(1) to
not link drti.o into the output object file, so the USDT probes are not created
during process startup. Instead, dtrace(1) will automatically discover and
create probes on the process' behalf when attaching.
Differential Revision: https://reviews.freebsd.org/D2203
Reviewed by: rpaulo
MFC after: 1 month
Even on Illumos, with its much larger KVA, ZFS ARC steps back if KVA usage
reaches certain threshold (3/4 on i386 or 16/17 otherwise). FreeBSD has
even less KVA, but had no such limit on archs with direct map as amd64.
As result, on machines with a lot of RAM, during load with very small user-
space memory pressure, such as `zfs send`, it was possible to reach state,
when there is enough both physical RAM and KVA (I've seen up to 25-30%),
but no continuous KVA range to allocate even single 128KB I/O request.
Address this situation from two sides:
- restore KVA usage limitations in a way the most close to Illumos;
- introduce new requirement for KVA fragmentation, specifying that we
should have at least one sequential KVA range of zfs_max_recordsize bytes.
Experiments show that first limitation done alone is not sufficient. On
machine with 64GB of RAM it is sometimes needed to drop up to half of ARC
size to get at leats one 1MB KVA chunk. Statically limiting ARC to half
of KVA/RAM is too strict, so second limitation makes it to work in cycles:
accumulate trash up to certain critical mass, do massive spring-cleaning,
and then start littering again. :)
MFC after: 1 month
This adds an upper bound, dtrace_ustackdepth_max, to the number of frames
traversed when computing the userland stack depth. Some programs - notably
firefox - are otherwise able to trigger an infinite loop in
dtrace_getustack_common(), causing a panic.
MFC after: 1 week
traps do appear in the regular call stack, rather than only in a special
trap frame, so we don't need to inject the trap-frame $pc into a returned
stack trace in DTrace.
MFC after: 3 days
Sponsored by: DARPA, AFRL
skip using the DTrace 'profile' provider on ARM. This causes stack traces
to skip various driver-and callout-related things as they do on x86, where
the likewise arbitrary values are '6' (32-bit) and '10' (64-bit) for
similar sorts of reasons.
MFC after: 3 days
Sponsored by: DARPA, AFRL
If zvol_geom_start is called with a BIO_DELETE from a thread which can
sleep it queues it for later processing by the zvol_geom_worker. The
zvol_geom_worker didn't have a delete case so would simply loose the bio
hence preventing the original caller from every completing. In addition
an other unknown types would suffer the same fate.
Allow zvol_geom_worker to process BIO_DELETE's via zvol_strategy and
return unsupported for all unknown bio types.
MFC after: 2 weeks
Sponsored by: Multiplay
emulate the instructions used in function entry and exit.
For function entry ARM will use a push instruction to push up to 16
registers to the stack. While we don't expect all 16 to be used we need to
handle any combination the compiler may generate, even if it doesn't make
sense (e.g. pushing the program counter).
On function return we will either have a pop or branch instruction. The
former is similar to the push instruction, but with care to make sure we
update the stack pointer and program counter correctly in the cases they
are either in the list of registers or not. For branch we need to take the
24-bit offset, sign-extend it, and add that number of 4-byte words to the
program counter. Care needs to be taken as, due to historical reasons, the
address the branch is relative to is not the current instruction, but 8
bytes later.
This allows us to use the following probes on ARM boards:
dtrace -n 'fbt::malloc:entry { stack() }'
and
dtrace -n 'fbt:🆓return { stack() }'
Differential Revision: https://reviews.freebsd.org/D2007
Reviewed by: gnn, rpaulo
Sponsored by: ABT Systems Ltd
expected to return the data in the memory location pointed at by target
after the operation. The FreeBSD atomic functions previously used return
either 0 or 1 to indicate if the comparison succeeded or not respectively.
With this change these functions only support ARMv6 and later are supported
by these functions.
Sponsored by: ABT Systems Ltd
dtrace is able to display a stack trace similar to the one below.
# dtrace -p 603 -n 'tcp:kernel::receive { stack(); }'
0 70 :receive
kernel`ip_input+0x140
kernel`netisr_dispatch_src+0xb8
kernel`ether_demux+0x1c4
kernel`ether_nh_input+0x3a8
kernel`netisr_dispatch_src+0xb8
kernel`ether_input+0x60
kernel`cpsw_intr_rx+0xac
kernel`intr_event_execute_handlers+0x128
kernel`ithread_loop+0xb4
kernel`fork_exit+0x84
kernel`swi_exit
kernel`swi_exit
Tested by: gnn
Sponsored by: ABT Systems Ltd
cannot happen on FreeBSD. r278136 overlooked the fact that a destructor
registered with devfs_set_cdevpriv(9) is invoked even in the case of an
error.
X-MFC-With: r278136
This allows dtrace to monitor the calls to txg_quiesce which can be really
helpful.
Also standardise __noinline order for arc_kmem_reap_now.
Sponsored by: Multiplay
ZFS already commits outstanding data every zfs_txg_timeout seconds, so these
syncs are unnecessarily intrusive.
Submitted by: gibbs
Sponsored by: Spectra Logic
MFSpectraBSD: 1105759 on 2014/12/11
Since allow_mounted is a FreeBSD-specific change, default to B_TRUE, then
locally check for the magic bit. Unconditionally check allow_mounted below.
Convert the setting of allow_mounted to an explicit boolean.
MFC after: 1 week
Sponsored by: Spectra Logic
MFSpectraBSD: 672578 (in part) on 2013/07/19
This is primarily for developer/debugging use; it enables built-in tagged
tracking of refcounts inside ZFS. It can only be enabled from the loader,
since it modifies how in-core state is managed. Default remains disabled.
MFC after: 1 week
Sponsored by: Spectra Logic
Remove the unnecessary #ifdef _KERNEL, which did not differ in the true or
false cases. Actually set the value of to_free before using it.
MFC after: 1 week
Sponsored by: Spectra Logic
dsl_dir_transfer_space() is mostly called after dsl_dir_diduse_space(),
which already calls dmu_buf_will_dirty() for the same dbuf and tx, so
its duplicate call in those cases will change nothing, only spend time.
Skipping this call by four times reduces time spent in dbuf_write_done()
and descendants, updating dataset statistics with several congested lock
acquisitions. When rewriting 8K zvol blocks at 1GB/s rate, this reduces
CPU time spent inside dbuf_write_done(), according to profiling, from 45%
of 683K samples to 18% of 422K.
MFC after: 2 weeks
A number of entries that can be present in the spa config shouldn't be saved
to disk so add a method to ensure this is case. Without this if the last
caller to vdev_config_generate requested stats then we can end up in the
cache file.
Also only skip a none writable pool in the cache file generation if its
active. This prevents unavailable pools incorrectly getting removed from
cache file.
Tested by: delphij
MFC after: 2 weeks
Sponsored by: Multiplay
Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.
Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.
MFC after: 1 month
Sponsored by: Multiplay
Previous throttling implementation approached problem from the wrong side.
It significantly limited useful delaying of TRIM requests and aggregation
potential, while not so much controlled TRIM burstiness under heavy load.
With this change random 4K write benchmarks (probably the worst case for
TRIM) show me IOPS increase by 20%, average latency reduction by 30%, peak
TRIM bursts reduction by 3 times and same peak TRIM map size (memory usage).
Also the new logic does not force map size down so heavily, really allowing
to keep deleted data for 32 TXG or 30 seconds under moderate load. It was
practically impossible with old throttling logic, which pushed map down to
only 64 segments.
Reviewed by: smh
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
New segment at the list head may block all TRIM requests until txg of that
segment can be processed. On my random I/O tests this change reduce peak
TRIM list length from 650 to 450 segments. Hopefully it should reduce TRIM
burstiness when list processing is unblocked.
MFC after: 2 weeks
On FreeBSD gethrtime() implemented via getnanouptime(), that has 1ms (1/hz)
precision. It makes primary sort key (timestamp) collision very possible.
In such situations sorting by secondary key of LBA is much more reasonable
then by totally meaningless zio pointer value.
With this change on multi-threaded synchronous ZVOL read I've measured 10%
throughput increase and average latency reduction.
MFC after: 2 weeks
When pools are unavailable their vdevs are also unavailable which means
that vdev_max_asize remains at the default zero. This default was being
used to calculate vs_esize resulting in a negative number as vdev_asize >
vdev_max_asize, which caused zpool list -v to display 16.0E for EXPANDSZ
of these vdevs.
It's redundant at the moment since it can be obtained from the trapframe
on the architectures where DTrace is supported, but this won't be the case
with ARM.
Resizing a ZFS ZVOL with debug enabled would result in a panic due to
recursion on dp_config_rwlock.
The upstream change "3464 zfs synctask code needs restructuring" changed
zvol_set_volsize to avoid the recursion on dp_config_rwlock, but this was
missed when originally merged in by r248571 due to significant differences
in our codebases in this area.
These changes also relied on bring in changes from upstream:
3557 dumpvp_size is not updated correctly when a dump zvol's size is
changed, which where also not present.
In order to help prevent future issues in this area a direct comparison
and diff minimisation from current upstream version (b515258) of zvol.c.
Differential Revision: https://reviews.freebsd.org/D1302
MFC after: 1 month
X-MFC-With: r276063 & r276066
Sponsored by: Multiplay
Use #define zfsdev_state_lock spa_namespace_lock instead of replacing all
zfsdev_state_lock with spa_namespace_lock to minimise changes from upstream.
Differential Revision: D1302
MFC after: 1 month
X-MFC-With r276063
Sponsored by: Multiplay
Also correct as per style(9) on the use of #ifdef comments.
This is a no-op change as pre-cursor to a full cleanup and merge with
upstream zvol changes.
Sponsored by: Multiplay
kernel does not panic with zfs_panic_recover.
Illumos issue:
5438 zfs_blkptr_verify should continue after zfs_panic_recover
Reported by: Coverity
CID: 1232014
As of r270383, the dbuf_compare comparator compares the dbuf
attributes in the following order:
db_level (indirect level)
db_blkid (block number)
db_state (current state)
the address of the element
Because db_state is being considered before the element's state,
changing of db_state would affect balancedness of the AVL tree,
even when the address of element compares differently. For
instance, in dbuf_create, db_state may be altered after the
node is inserted into the AVL tree and may break AVL tree
balancedness.
Instead of using db_state as a comparision critera (introduced
in r270383), consider it only when we are doing a lookup, that
is one of the two dbuf pointers contains DB_SEARCH.
Illumos issue:
5422 preserve AVL invariants in dn_dbufs
MFC after: 2 weeks
into namecache, to avoid cache trashing when doing large operations.
E.g., tar archive extraction is not usually followed by access to many
of the files created.
Right now, each VOP_LOOKUP() implementation explicitely knowns about
this quirk and tests for both MAKEENTRY flag presence and op != CREATE
to make the call to cache_enter(). Centralize the handling of the
quirk into VFS, by deciding to cache only by MAKEENTRY flag in VOP.
VFS now sets NOCACHE flag for CREATE namei() calls.
Note that the change in semantic is backward-compatible and could be
merged to the stable branch, and is compatible with non-changed
third-party filesystems which correctly handle MAKEENTRY.
Suggested by: Chris Torek <torek@pi-coral.com>
Reviewed by: mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Convert ARC flags to use enum. Previously, public flags are defined in
arc.h and private flags are defined in arc.c which can lead to confusion
and programming errors.
Consistently use 'hdr' (when referencing arc_buf_hdr_t) instead of 'buf'
or 'ab' because arc_buf_t are often named 'buf' as well.
Illumos issue:
5369 arc flags should be an enum
5370 consistent arc_buf_hdr_t naming scheme
MFC after: 2 weeks
Remove "dbuf phys" db->db_data pointer aliases.
Use function accessors that cast db->db_data to the appropriate
"phys" type, removing the need for clients of the dmu buf user
API to keep properly typed pointer aliases to db->db_data in order
to conveniently access their data.
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_leaf.c:
In zap_leaf() and zap_leaf_byteswap, now that the pointer alias
field l_phys has been removed, use the db_data field in an on
stack dmu_buf_t to point to the leaf's phys data.
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c:
Remove the db_user_data_ptr_ptr field from dbuf and all logic
to maintain it.
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dir.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_micro.c:
Modify the DMU buf user API to remove the ability to specify
a db_data aliasing pointer (db_user_data_ptr_ptr).
cddl/contrib/opensolaris/cmd/zdb/zdb.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_diff.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_objset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_tx.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_bookmark.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_deadlist.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_deleg.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dir.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_pool.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_synctask.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_userhold.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_history.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_leaf.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zap_micro.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dataset.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dir.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_impl.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h:
Create and use the new "phys data" accessor functions
dsl_dir_phys(), dsl_dataset_phys(), zap_m_phys(),
zap_f_phys(), and zap_leaf_phys().
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dataset.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dsl_dir.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_impl.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zap_leaf.h:
Remove now unused "phys pointer" aliases to db->db_data
from clients of the DMU buf user API.
Illumos issue:
5314 Remove "dbuf phys" db->db_data pointer aliases in ZFS
MFC after: 2 weeks
In addition to r273158, make the code in spa_sync() that checks if the
current TXG is a no-op TXG less fragile.
Illumos issue:
5347 idle pool may run itself out of space
MFC after: 2 weeks
Add a loader tunable, vfs.zfs.arc_meta_min, which controls how much metadata
ZFS should keep in ARC at minimum.
In arc_evict(), when doing recycle, take more factors into account by
applying the following policy:
1. If no evictable data, evict metadata;
2. If no evictable metadata, evict data;
3. If we hit arc_meta_limit, evict metadata;
4. If we haven't hit arc_meta_min, evict data;
5* (Illumos only, not present in new FreeBSD code, yet) evict the oldest
cached element from data and metadata.
(FreeBSD) evict the data type specified by caller, which is the
existing behavior.
Note that because of our splitted locks (implemented in r205231 to improve
scalability by reducing lock contention), implementing the fifth Illumos
behavior will not be cheap, so for now just implement the 1-4 and fall back
to current behavior for 5.
Illumos issue:
5368 ARC should cache more metadata
MFC after: 2 months (assuming we didn't found better solution)
Expose arc_meta_limit, et al via kstats.
Note that as a result, vfs.zfs.arc_meta_used is removed.
The existing vfs.zfs.arc_meta_limit sysctl/tunable is retained
with a SYSCTL_PROC wrapper.
Illumos ZFS issues:
3561 arc_meta_limit should be exposed via kstats
Relnotes: yes
MFC after: 2 weeks
Verify that the block pointer is structurally valid, before attempting to
read it in. It can only be invalid in the case of a ZFS bug, but this
change will help identify such bugs in a more transparent way, by
panic'ing with a relevant message, rather than indexing off the end of an
array or something.
Illumos issue:
5349 verify that block pointer is plausible before reading
MFC after: 2 weeks
Reduce scrub activities when system there is enough dirty data, namely when
dirty data is more than zfs_vdev_async_write_active_min_dirty_percent (once
we start to increase the number of concurrent async writes).
While there also correct rounding error which would make scrub end up
pausing for (zfs_txg_timeout + 1) seconds instead of the desired
zfs_txg_timeout seconds.
Illumos issue:
5351 scrub goes for an extra second each txg
5352 scrub should pause when there is some dirty data
MFC after: 2 weeks
If zio_checksum_error() returns other than ECKSUM (e.g. EINVAL), it does not
fill in the "zio_bad_cksum_t *info" parameter. Caller should not attempt to
use it in this case.
Illumos issue:
5348 zio_checksum_error() only fills in info if ECKSUM
MFC after: 2 weeks
If a dnode has a spill block and there is an error while accessing
a data block then traverse_dnode() loses information about that error
and returns a status of visiting the spill block.
This issue is discovered by Spectra Logic.
Illumos issue:
5311 traverse_dnode may report success when it should not
Original author: gibbs
MFC after: 2 weeks
When importing a pool, don't assume that the passed pool configuration
at vdev_load is always vaild. It's possible that a stale configuration
that comes with extra vdevs, where metaslab_init() would fail because
of lower layer returns error.
Change the code to make metaslab_init() handle and return errors from
lower layer and pass it back to upper layer and handle it there.
Illumos issue:
5213 panic in metaslab_init due to space_map_open returning ENXIO
MFC after: 2 weeks
In the old days callout(9) had 1 tick precision and that was inadequate
for some uses, e.g. DTrace profile module, so we had to emulate cyclic
API and behavior. Now we can directly use callout(9) in the very few
places where cyclic was used.
Differential Revision: https://reviews.freebsd.org/D1161
Reviewed by: gnn, jhb, markj
MFC after: 2 weeks
In dsl_dataset_hold_obj() we used zap_contains(.., DS_FIELD_LARGE_BLOCKS)
to determine whether the extensible (zapifyed) dataset have large blocks.
The code expects the result be either 0 (found) or ENOENT (not found),
however reused the variable 'err' which later code expects to be 0.
Fix this by adopting similar code construct that is used later for
DS_FIELD_BOOKMARK_NAMES, which uses a temporary variable zaperr to catch
errors from zap_* rountines.
Reported by: Peter J. Creath (on FreeNAS; FreeNAS bug #6848)
Illumos issue: 5393 spurious failures from dsl_dataset_hold_obj()
Reviewed by: mahrens
Sponsored by: iXsystems, Inc.
X-MFC with: r274337
It is implemented for LUNs backed by ZVOLs in "dev" mode and files.
GEOM has no such API, so for LUNs backed by raw devices all LBAs will
be reported as mapped/unknown.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
In file included from cddl/contrib/opensolaris/common/ctf/ctf_create.c:31:
In file included from sys/cddl/contrib/opensolaris/uts/common/sys/sysmacros.h:34:
sys/cddl/contrib/opensolaris/uts/common/sys/isa_defs.h:334:9: warning: '_ILP32' macro redefined [-Wmacro-redefined]
#define _ILP32
^
<built-in>:26:9: note: previous definition is here
#define _ILP32 1
^
1 warning generated.
This is because clang 3.5.0 started predefining _ILP32 and __ILP32__ for
the i386 arch. (Earlier versions already predefined _LP64 and __LP64__
for the x86_64 arch.)
Reviewed by: emaste, avg, smh, delphij, markj
Differential Revision: https://reviews.freebsd.org/D1187
This rounding up was lost in a mismerge of illumos code.
See r268075 MFV r267565.
After that commit zio_compress_data() no longer performs any compressed
size adjustment, so it needs to be done externally. On FreeBSD we round
up the size using vdev_ashift rather than SPA_MINBLOCKSIZE so that 4KB
devices are properly supported.
Additionally, zero out the buffer tail only if compression succeeds.
The compression is considered successful if the size of compressed
data after rounding up to account for the vdev ashift is less than the
original data size. It does not make sense to have the data compressed
if all the savings are lost to rounding up.
With the new zio_compress_data() it could have been possible that the
rounded compressed size would be greater than the original size and thus
we could zero beyond the allocated buffer if the zeroing code was kept
at the original place.
Discussed with: delphij, gibbs
MFC after: 2 weeks
X-MFC with: r274627
Size of physical ZIOs must never be implicitly adjusted, it's
a responsibility of a caller to make sure that such a ZIO has proper offset
and size.
Discussed with: delphij, gibbs
MFC after: 2 weeks
After r265152 TRIM requests are ZIO_TYPE_FREE instead of ZIO_TYPE_IOCTL
this meant file backed vdevs to attempted to process the ZIO as a write
causing a panic.
We now disable TRIM on file backed vdevs and ASSERT the ZIO types supported
by each vdev type to ensure we explicity support the ZIO type being
processed.
Also ensure that TRIM on init is not procesed for devices which declare they
didn't support TRIM via vdev_notrim.
PR: 195061, 194976, 191573
Sponsored by: Multiplay
have both kern_open() and kern_openat(); change the callers to use
kern_openat().
This removes one (sometimes two) levels of indirection and
consolidates arguments checks.
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
ZFS large block support.
Please note that booting from datasets that have recordsize greater
than 128KB is not supported (but it's Okay to enable the feature on
the pool). This *may* remain unchanged because of memory constraint.
Limited safety belt is provided for mounted root filesystem but use
caution is advised.
Illumos issue:
5027 zfs large block support
MFC after: 1 month
We have observed that arc_release() can be called concurrently with a
l2arc in-flight write.
Also, we have observed that arc_hdr_destroy() can be called from
arc_write_done() for a zio with ZIO_FLAG_IO_REWRITE flag in similar
circumstances.
Previously the l2arc headers would be freed while leaking their
associated compression buffers. Now the buffers are placed on
l2arc_free_on_write list for delayed freeing. This is similar to what
was already done to arc buffers that were supposed to be freed
concurrently with in-flight writes of those buffers.
In addition to fixing the discovered leaks this change also adds some
protective code to assert that a compression buffer associated with a
l2arc header is never leaked.
A new kstat l2_cdata_free_on_write is added. It keeps a count of
delayed compression buffer frees which previously would have been leaks.
Tested by: Vitalij Satanivskij <satan@ukr.net> et al
Requested by: many
MFC after: 2 weeks
Sponsored by: HybridCluster / ClusterHQ
For ZVOL-backed LUNs this allows to inform initiators if storage's used or
available spaces get above/below the configured thresholds.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
crash.sh script attached to FreeNAS bug 4109:
https://bugs.freenas.org/issues/4109
Three are in the snapshot layer:
a) AVG explains in his notes: https://wiki.freebsd.org/AvgVfsSolarisVsFreeBSD
"VOP_INACTIVE must not do any destructive actions to a vnode
and its filesystem node, nor invalidate them in any way."
gfs_vop_inactive and zfsctl_snapshot_inactive did just that. In
OpenSolaris VOP_INACTIVE is much closer to FreeBSD's VOP_RECLAIM.
Rename & move them to gfs_vop_reclaim and zfsctl_snapshot_reclaim
and merge in the requisite vnode_destroy from zfsctl_common_reclaim.
b) gfs_lookup_dot and various zfsctl functions do not honor the
FreeBSD VFS convention of only locking from the root downward. When
looking up ".." the convention is to drop the current leaf vnode lock before
acquiring the directory vnode and then subsequently re-acquiring the lock on the
leaf vnode. This fixes that in all the places that our exercised by crash.sh.
c) The snapshot may already be unmounted when the directory vnode is reclaimed.
Check for this case and return.
One in the common layer:
d) Callers of traverse expect the reference to the vnode passed in to be
maintained. Don't release it.
This last one may be an unclear contract. There may in fact be some callers that
do expect the reference to be dropped on success in addition to callers that
expect it to be released. In this case a further audit of the callers is needed
and a consensus on the correct behavior.
PR: 184677
Submitted by: kmacy
Reviewed by: delphij, will, avg
MFC after: 2 weeks
Sponsored by: iXsystems
* Use a constant to define the number of stack frames in a probe exception.
* Only allow function symbols in powerpc64 ('.' prefixed)
* Set the fbtp_roffset for return probes, so the correct dtrace_probe call is
made.
MFC after: 1 week
- Wrong integer type was specified.
- Wrong or missing "access" specifier. The "access" specifier
sometimes included the SYSCTL type, which it should not, except for
procedural SYSCTL nodes.
- Logical OR where binary OR was expected.
- Properly assert the "access" argument passed to all SYSCTL macros,
using the CTASSERT macro. This applies to both static- and dynamically
created SYSCTLs.
- Properly assert the the data type for both static and dynamic
SYSCTLs. In the case of static SYSCTLs we only assert that the data
pointed to by the SYSCTL data pointer has the correct size, hence
there is no easy way to assert types in the C language outside a
C-function.
- Rewrote some code which doesn't pass a constant "access" specifier
when creating dynamic SYSCTL nodes, which is now a requirement.
- Updated "EXAMPLES" section in SYSCTL manual page.
MFC after: 3 days
Sponsored by: Mellanox Technologies
in userland rename in-kernel getenv()/setenv() to kern_setenv()/kern_getenv().
This fixes a namespace collision with libc symbols.
Submitted by: kmacy
Tested by: make universe
When processing async destroys ZFS would leak space every txg timeout
(5 seconds by default), if no writes occurred, until the pool is totally
full. At this point it would be unfixable without a pool recreation.
In addition if the machine was rebooted with the pool in this situation
would fail to import on boot, hanging indefinitely, as the import process
requires the ability to write data to the pool. Any attempts to query the
pool status during the hung import would not return as the import holds
the pool lock.
The only way to import such a pool would be to specify -o readonly=on
to the zpool import.
zdb -bb <pool> can be used to check for "deferred free" size which is where
this lost space will be counted.
MFC after: 3 days
Sponsored by: Multiplay
Without this change the accounting of L2ARC usage would be wrong and
give 16EB free space because the number became negative and overflows.
Obtained from: FreeNAS (issue #6239)
MFC after: 2 weeks
controls how much fraction, 1/2^arc_shrink_shift, should be reclaimed
when there is memory pressure.
Submitted by: Richard Kojedzinszky <krichy at tvnetwork.hu>
MFC after: 2 weeks
Refactor the code and stop restore_object from creating two transactions.
Illumos issue:
3693 restore_object uses at least two transactions to restore an object
MFC after: 2 weeks
FreeBSD has ARC_BUFC_NUMMETADATALISTS metadata lists and ARC_BUFC_NUMDATALISTS
data lists (currently both are 16) while illumos has just a single list
of each kind.
headroom determines how much data is scanned on a single list
during each run of the l2arc feed thread.
Because FreeBSD has more lists we proportionally decrease the limit.
Reviewed by: Brendan Gregg (earlier version)
MFC after: 2 weeks
Sponsored by: HybridCluster
FreeBSD has ARC_BUFC_NUMMETADATALISTS metadata lists and ARC_BUFC_NUMDATALISTS
data lists (currently both are 16) while illumos has just a single list
of each kind.
L2ARC_WRITE_SIZE determines the default value of l2arc_write_max which
defines limits on how much data is scanned and written to a cache device
during each run of the l2arc feed thread. The limits are applied on the
per buffer list basis.
Because FreeBSD has more lists we proportionally reduce the limits.
Reviewed by: Brendan Gregg (earlier version)
MFC after: 2 weeks
Sponsored by: HybridCluster
Don't inherit flags other than DS_FLAG_CI_DATASET and DS_FLAG_INCONSISTENT
when cloning. This prevents DS_FLAG_DEFER_DESTROY being inherited from a
clone that is marked for deferred destroy, which causes snapshots of the
clone being destroyed when getting a hold or clone.
Illumos issue:
5150 zfs clone of a defer_destroy snapshot causes strangeness
MFC after: 1 week
Add tunable for number of metaslabs per vdev
(vfs.zfs.vdev.metaslabs_per_vdev). The default remains
at 200.
Illumos issue:
5161 add tunable for number of metaslabs per vdev
MFC after: 2 weeks
In arc_kmem_reap_now(), reap range_seg_cache too to reclaim memory in
response of memory pressure.
Illumos issue:
5163 arc should reap range_seg_cache
MFC after: 1 week
Make space_map_truncate() always do space_map_reallocate(). Without
this, setting space_map_max_blksz would cause panic for existing pool,
as dmu_objset_set_blocksize would fail if the object have multiple blocks.
Illumos issues:
5164 space_map_max_blksz causes panic, does not work
5165 zdb fails assertion when run on pool with recently-enabled
spacemap_histogram feature
MFC after: 2 weeks
Remove previously added kmem methods in favour of defines which
allow diff minimisation between upstream code base.
Rebalance ARC free target to be vm_pageout_wakeup_thresh by default
which eliminates issue where ARC gets minimised instead of balancing
with VM pageout. The restores the target point prior to r270759.
Bring in missing upstream only changes which move unused code to
further eliminate code differences.
Add additional DTRACE probe to aid monitoring of ARC behaviour.
Enable upstream i386 code paths on platforms which don't define
UMA_MD_SMALL_ALLOC.
Fix mixture of byte an page values in arc_memory_throttle i386 code
path value assignment of available_memory.
PR: 187594
Review: D702
Reviewed by: avg
MFC after: 1 week
X-MFC-With: r270759 & r270861
Sponsored by: Multiplay
When performing snapshot renames we could deadlock due to the locking
in zvol_rename_minors. In order to avoid this use the same workaround
as zvol_open in zvol_rename_minors.
Add missing zvol_rename_minors to dsl_dataset_promote_sync.
Protect against invalid index into zv_name in zvol_remove_minors.
Replace zvol_remove_minor calls with zvol_remove_minors to ensure
any potential children are also renamed.
Don't fail zvol_create_minors if zvol_create_minor returns EEXIST.
Restore the valid pool check in zfs_ioc_destroy_snaps to ensure we
don't call zvol_remove_minors when zfs_unmount_snap fails.
PR: 193803
MFC after: 1 week
Sponsored by: Multiplay
This fix addresses only issues with the pynfs reports, none of these
issues are know to create problems for extant real clients.
Submitted by: Bart Hsiao <bart.hsiao@gmail.com>
Reworked by: myself
Reviewed by: rmacklem
Approved by: rmacklem
Sponsored by: QNAP Systems Inc.
This is checked for in the zfs_snapshot_004_neg STF/ATF test (currently
still in projects/zfsd rather than head).
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c:
- zfsvfs_create(): Check whether the objset name fits into
statfs.f_mntfromname, and return ENAMETOOLONG if not. Although
the filesystem can be unmounted via the umount(8) command, any
interface that relies on iterating on statfs (e.g. libzfs) will
fail to find the filesystem by its objset name, and thus assume
it's not mounted. This causes "zfs unmount", "zfs destroy",
etc. to fail on these filesystems, whether or not -f is passed.
MFC after: 1 month
Sponsored by: Spectra Logic
MFSpectraBSD: 974872 on 2013/08/09
This is primarily only of interest to ZFS developers, but it makes it
easier to get additional debugging.
Submitted by: gibbs
MFC after: 1 month
Sponsored by: Spectra Logic
MFSpectraBSD: 517074 on 2011/12/15 (by will), 662343 on 2013/03/20 (by gibbs)
If bpobj_space() returned non-zero here, the sublist would have been
left open, along with the bonus buffer hold it requires. This call
does not invoke any calls to bpobj_close() itself.
This bug doesn't have any known vector, but was found on inspection.
MFC after: 1 week
Sponsored by: Spectra Logic
Affects: All ZFS versions starting 21 May 2010 (illumos cde58dbc)
MFSpectraBSD: r1050998 on 2014/03/26
Summary:
Fix the stack tracing for dtrace/powerpc by using the trapexit/asttrapexit
return address sentinels instead of checking within the kernel address space.
As part of this, I had to add new inline functions. FBT traces the kernel, so
we have to have special case handling for this, since a trap will create a full
new trap frame, and there's no way to pass around the 'real' stack. I handle
this by special-casing 'aframes == 0' with the trap frame. If aframes counts
out to the trap frame, then assume we're looking for the full kernel trap frame,
so switch to the real stack pointer.
Test Plan: Tested on powerpc64
Reviewers: rpaulo, markj, nwhitehorn
Reviewed By: markj, nwhitehorn
Differential Revision: https://reviews.freebsd.org/D788
MFC after: 3 week
Relnotes: Yes
* vfs.zfs.vdev.async_write_active_min_dirty_percent
* vfs.zfs.vdev.async_write_active_max_dirty_percent
Added validation of min / max for ZFS sysctl
* vfs.zfs.dirty_data_max_percent
MFC after: 3 days
Correctly report hole at end of file.
When asked to find a hole, the DMU sees that there are no holes in the
object, and returns ESRCH. The ZPL interprets this as "no holes before
the end of the file", and therefore inserts the "virtual hole" at the
end of the file. Because DMU and ZPL have different ideas of where the
end of an object/file is, we will end up returning the end of file,
which is generally larger, instead of returning the end of object.
The fix is to handle the "virtual hole" in the DMU. If no hole is found,
the DMU will return a hole at the end of the file, rather than an error.
Illumos issue:
5139 SEEK_HOLE failed to report a hole at end of file
MFC after: 1 week
In zil_claim, don't issue warning if we get EBUSY (inconsistent) when
opening an objset, instead, ignore it silently.
Illumos issue:
5140 message about "%recv could not be opened" is printed when booting after crash
MFC after: 1 week
Add a new tunable/sysctl, vfs.zfs.free_max_blocks, which can be used to
limit how many blocks can be free'ed before a new transaction group is
created. The default is no limit (infinite), but we should probably have
a lower default, e.g. 100,000.
With this limit, we can guard against the case where ZFS could run out of
memory when destroying large numbers of blocks in a single transaction
group, as the entire DDT needs to be brought into memory.
Illumos issue:
5138 add tunable for maximum number of blocks freed in one txg
MFC after: 2 weeks
Enforce 4K as smallest indirect block size (previously the smallest
indirect block size was 1K but that was never used).
This makes some space estimates more accurate and uses less memory
for some data structures.
Illumos issue:
5141 zfs minimum indirect block size is 4K
MFC after: 2 weeks
In dnode_sync(), do dnode_increase_indirection() before processing
the dn_next_nblkptr.
Illumos issue:
5117 space map reallocation can cause corruption
MFC after: 3 days
Also restore kmem_used() check for i386 as it has KVA limits that the raw
page counts above don't consider
PR: 187594
Reviewed by: peter
X-MFC-With: r270759
Review: D700
Sponsored by: Multiplay
Prior to this change we triggered ARC reclaim when kmem usage passed 3/4
of the total available, as indicated by vmem_size(kmem_arena, VMEM_ALLOC).
This could lead large amounts of unused RAM e.g. on a 192GB machine with
ARC the only major RAM consumer, 40GB of RAM would remain unused.
The old method has also been seen to result in extreme RAM usage under
certain loads, causing poor performance and stalls.
We now trigger ARC reclaim when the number of free pages drops below the
value defined by the new sysctl vfs.zfs.arc_free_target, which defaults
to the value of vm.v_free_target.
Credit to Karl Denninger for the original patch on which this update was
based.
PR: 191510 and 187594
Tested by: dteske
MFC after: 1 week
Relnotes: yes
Sponsored by: Multiplay
tracepoints would continue to generate traps, which would be ignored but
could consume noticeable amounts of CPU if, say, all functions in the kernel
were instrumented.
X-MFC-With: r270067
duplicating the entire implementation for both x86 and powerpc. This makes
it easier to add support for other architectures and has no functional
impact.
Phabric: D613
Reviewed by: gnn, jhibbits, rpaulo
Tested by: jhibbits (powerpc)
MFC after: 2 weeks
In vdev_get_stats, check that the vdev is not a hole before computing the
fragmentation. This fixes a panic when removing log device.
Illumos issue:
5049 panic when removing log device
Author: Alex Reece <alex@delphix.com>
MFC after: 2 weeks
Encode CPU's number by XOR'ing the CPU ID against the 64-bit cpu_ticks().
Reviewed by: mav, gibbs
Differential Revision: https://phabric.freebsd.org/D521
MFC after: 2 weeks
In dnode_children_t, use C99's "[]" idiom for declaring the variable
sized array dnc_children at the end of the structure.
This prevents the compiler from mistakenly optimizing away accesses
beyond the array's defined size.
Illumos issue:
5038 Remove "old-style" flexible array usage in ZFS.
Author: Justin T. Gibbs <justing@spectralogic.com>
MFC after: 2 weeks
This prevents recursion of vdev_queue_io_done as per r265321 but
using a different method as recommended on the openzfs list.
We now use zio_interrupt(zio) and return ZIO_PIPELINE_STOP instead
of returning ZIO_PIPELINE_CONTINUE from vdev_*_io_start methods.
zio_vdev_io_start now ASSERTS the that vdev_op_io_start returns
ZIO_PIPELINE_STOP to ensure future changes don't reintroduce
ZIO_PIPELINE_CONTINUE returns.
Cleanup flow in vdev_geom_io_start while I'm here.
Also fix some cases not using SET_ERROR(..)
MFC after: 2 weeks
X-MFC-With: r265321
