future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.
The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.
The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).
Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho
Introduce a new KPI that verifies if the page cache is empty for a
specified vm_object. This KPI does not make assumptions about the
locking in order to be used also for building assertions at init and
destroy time.
It is mostly used to hide implementation details of the page cache.
Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: alc (vm_radix based version)
Tested by: flo, pho, jhb, davide
the pid provider on a kernel compiled with INVARIANTS.
sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c:
In fasttrap_probe_pid(), attempts to write to the
address space of the thread that fired the probe
must be performed with the process of the thread
held. Use _PHOLD() to ensure this is the case.
In fasttrap_probe_pid(), use proc_write_regs() instead
of calling set_regs() directly. proc_write_regs()
performs invariant checks to verify the calling
environment of set_regs(). PROC_LOCK()/UNLOCK() around
the call to proc_write_regs() so that it's invariants
are satisfied.
Sponsored by: Spectra Logic Corporation
Reviewed by: gnn, rpaulo
MFC after: 1 week
necessary because we already use parenthesis in zfs_cv_init().
This fixes a long standing bug where there would be an extra ")" at the
end of the string. This extra parenthesis would show up in the WCHAN of
the process (top, stty status, etc.).
- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.
- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.
- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.
- The cap_getrights(2) syscall is renamed to cap_rights_get(2).
- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.
- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).
- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.
- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.
- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:
CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.
Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).
Added CAP_SYMLINKAT:
- Allow for symlinkat(2).
Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).
Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.
Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.
Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.
Removed CAP_MAPEXEC.
CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.
Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).
Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.
CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).
CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).
Added convinient defines:
#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE
#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)
Added defines for backward API compatibility:
#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)
Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib
Import a fix tighten assertion on SPA versions from vendor (Illumos).
Illumos ZFS issue:
3543 Feature flags causes assertion in spa.c to miss certain cases
MFC after: 2 weeks
Merge new read-only zfs properties from vendor (illumos)
Illumos ZFS issues:
3588 provide zfs properties for logical (uncompressed) space used and
referenced
References:
https://www.illumos.org/issues/3588
MFC after: 2 weeks
in r247265 (ZFS deadman thread). Both new utilities now support the old
kernel and new kernel properly detects old utilities.
For future backwards compatibility, the vfs.zfs.version.ioctl read-only
sysctl has been introduced. With this sysctl zfs utilities will be able
to detect the ioctl interface version of the currently loaded zfs module.
As a side effect, the zfs utilities between r247265 and this revision don't
support the old kernel module. If you are using HEAD newer or equal than
r247265, install the new kernel module (or whole kernel) first.
MFC after: 10 days
Merge the ZFS I/O deadman thread from vendor (illumos).
This feature panics the system on hanging ZFS I/O, helps debugging
and resumes failed service.
The panic behavior can be controlled with the loader-only tunables:
vfs.zfs.deadman_enabled (enable or disable panic on stalled ZFS I/O)
vfs.zfs.deadman_synctime (expiration time for stalled ZFS I/O)
By default, ZFS I/O deadman is enabled by default on amd64 and i386
excluding virtual guest machines.
Illumos ZFS issues:
3246 ZFS I/O deadman thread
References:
https://www.illumos.org/issues/3246
MFC after: 2 weeks
process that has crashed.
sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c:
In fasttrap_pid_disable(), we cannot PHOLD the proc
structure for a process that no longer exists, but
we still have other, fasttrap specific, state that
must be cleaned up for probes that existed in the
dead process. Instead of returning early if the
process related to our probes isn't found,
conditionalize the locking and carry on with a NULL
proc pointer. The rest of the fasttrap code already
understands that a NULL proc is possible and does
the right things in this case.
Sponsored by: Spectra Logic Corporation
Reviewed by: rpaulo, gnn
MFC after: 1 week
Fixes several problems if working with read-only pools.
Changed code originaly introduced in onnv-gate 13061:bda0decf867b
Contains changes up to illumos-gate 13700:4bc0783f6064
PR: kern/175897
Suggested by: avg
MFC after: 2 weeks
Import vendor bugfixes regarding SA rounding, header size and layout.
This was already partially fixed by avg.
Illumos ZFS issues:
3512 rounding discrepancy in sa_find_sizes()
3513 mismatch between SA header size and layout
References:
https://www.illumos.org/issues/3512https://www.illumos.org/issues/3513
MFC after: 2 weeks
* Illumos zfs issue #3035 [1] LZ4 compression support in ZFS.
LZ4 is a new high-speed BSD-licensed compression algorithm created
by Yann Collet that delivers very high compression and decompression
performance compared to lzjb (>50% faster on compression, >80% faster
on decompression and around 3x faster on compression of incompressible
data), while giving better compression ratio [1].
This version of LZ4 corresponds to upstream's [2] revision 85.
Please note that for obvious reasons this is not backward read
compatible. This means once a pool have LZ4 compressed data, these
data can no longer be read by older ZFS implementations.
Local changes:
- On-stack hash table disabled and using kernel slab allocator
instead, at this time. This requires larger kernel thread stack
for zio workers. This may change in the future should we adjusted
the zio workers' thread stack size.
- likely and unlikely will be undefined if they are already defined,
this is required for i386 XEN build.
- Removed De Bruijn sequence based __builtin_ctz family of builtins
in favor of the latter. Both GCC and clang supports these builtins.
- Changed the way the LZ4 code detects endianness.
- Manual pages modifications to mention the feature based on Illumos
counterpart.
- Boot loader changes to make it support LZ4 decompression.
[1] https://www.illumos.org/issues/3035
[2] http://code.google.com/p/lz4/source/list
Obtained from: Illumos (13921:9d721847e469)
Tested on: FreeBSD/amd64
MFC after: 1 month
A special gfs vnode corresponds to that object.
A regular zfs vnode must not be returned.
This should be upstreamed.
Reported by: pluknet
Submitted by: rmacklem
Tested by: pluknet
MFC after: 10 days
Now they are split into two pairs: page_hold/page_unhold for mappedread
and page_busy/page_unbusy for update_pages.
For mappedread we simply hold a page that is to be used as a source if it
is resident and valid (and not busy). This is sufficient since we are
only doing page -> user buffer copying. There is no page <-> backing
storage I/O involved.
update_pages is now better split to properly handle the putpages case
(page -> arc) and the regular write case (arc -> page).
For the latter we use complete protocol of marking an object with
paging-in-progress and marking a page with io_start (busy count).
Also, in this case we remove the write bit from all page mappings and
clear dirty bits of the pages, the former is needed to ensure that the
latter does the right thing.
Additionally we update a page if it is cached instead of just freeing it
as was done before. This needs to be verified.
A minor detail: ZFS-backed pages should always be either fully valid
or fully invalid. Assert this and use simpler API that does not deal
with sub-page blocks.
Reviewed by: kib
MFC after: 26 days
- there is no such flag in Solaris and derivatives
- the flag was added in an unrelated change
- the flag is not used
The proper way to allocate zeroed out memory is to use kmem_zalloc.
MFC after: 3 days
This should allow the kernel linker to easily detect a situation
when the module is present both in a kernel and in a preloaded file
(zfs.ko).
Reviewed by: jhb
MFC after: 5 days
It seems that old ZFS versions (v15) completely omit "vdev_children"
property when there is a single child.
Reported by: jase
Tested by: jase
MFC after: 1 week
the underlying zap_count() to return no errors. However, it is possible
that the pool reaches to such a state where zap_count would return error,
leading to panics when a pool is imported.
This commit changes the ddt_zap_count to return error returned from
zap_count and handle the error appropriately. With this change, it's now
possible to let zpool rollback damaged transaction groups and import the
pool.
Obtained from: ZFS on Linux github (e8fd45a0f9)
MFC after: 1 month
- Use spinlock_enter()/spinlock_exit() to prevent a thread holding a
debug lock from being preempted to prevent other threads waiting
on that lock from starvation.
- Handle the possibility of CPU migration in between the fetch of curcpu
and the call to spinlock_enter() by saving curcpu in a local variable.
- Use memory barriers to prevent reordering of loads and stores of the
data protected by the lock outside of the critical section
- Eliminate false sharing of the locks by moving them into the structures
that they protect and aligning them to a cacheline boundary.
- Record the owning thread in the lock to make debugging future problems
easier.
Reviewed by: rpaulo (initial version)
MFC after: 2 weeks
initialisation to be enabled (1) / disabled (0) defaults to enabled.
This is useful for devices which have a slow trim speed and are either
new or have otherwise already been wiped e.g. secure erase.
PR: kern/173116
Submitted by: Steven Hartland
Approved by: pjd (mentor)
making range consolidation much more effective particularly for small
deletes.
This reduces memory used by the free map as well as reducing the number
of bio requests down to geom required to process all deletes.
In tests this achieved a factor of 10 reduction of trim ranges / geom
call downs.
While I'm here correct the description of zio_vdev_io_start.
PR: kern/173254
Submitted by: Steven Hartland
Approved by: pjd (mentor)
Also, make it explicit that V_XATTRDIR is not properly supported in gfs
code yet.
The bad code was plain incorrect: (a) it spoiled handling of v_usecount
reaching zero and (b) it leaked v_holdcnt.
The ugly code employs potentially unsafe locking tricks.
Ideally we should separate vnode lifecycle and gfs node lifecycle.
A gfs node should have its own reference count where its child nodes
should be accounted.
PR: kern/151111
Reviewed by: kib
MFC after: 13 days
Introduce a new dataset aclmode setting "restricted" to protect ACL's
being destroyed or corrupted by a drive-by chmod.
illumos-gate 13889:a67716f16746
3254 add support in zfs for aclmode=restricted
References:
https://www.illumos.org/issues/3254
MFC after: 2 weeks
Import the zio nop-write improvement from Illumos. To reduce I/O,
nop-write omits overwriting data if the checksum (cryptographically
secure) of new data matches the checksum of existing data.
It also saves space if snapshots are in use.
It currently works only on datasets with enabled compression, disabled
deduplication and sha256 checksums.
IllumOS 13887:196932ec9e6a and 13888:7204b3392a58
3236 zio nop-write
References:
https://www.illumos.org/issues/3236
MFC after: 2 weeks
* There is no need for the delayed destruction of znodes via taskqueue,
now that we do not need to fear recursion from getnewvnode into
zfs_inactive and zfs_freebsd_reclaim, thus making znode/vnode state
machine a bit simpler.
* More complete porting of zfs_inactive from Solaris VFS model to FreeBSD
vop_inactive and vop_reclaim model. All destructive actions are done
in zfs_freebsd_reclaim.
This allows to simplify zfs_zget logic.
* Allow zfs_zget to return a doomed vnode if the current thread already
has an exclusive lock on the vnode.
* Clean up Solaris-isms like bailing out of reclaim/inactive on certain
values of v_usecount (aka v_count) or directly messing with this counter.
* Do not clear z_vnode while znode is still accessible.
z_vnode should be cleared only after zfs_znode_dmu_fini.
Otherwise zfs_zget may get an effectively half-deconstructed znode.
This allows to simplify zfs_zget logic further.
The above changes fix at least two known/reported problems:
o An indefinite wait in the following code path:
vgone -> VOP_RECLAIM -> zfs_freebsd_reclaim -> vnode_destroy_vobject ->
put_pages -> zfs_write -> zil_commit -> zfs_zget
This happened because vgone marks a vnode as VI_DOOMED before calling
VOP_RECLAIM, but zfs_zget would not return a doomed vnode under any
circumstances.
The fix in this change is not complete as it won't fix a deadlock between
two threads doing VOP_RECLAIM where one thread is in zil_commit trying to
zfs_zget a znode/vnode being reclaimed by the other thread, which would be
blocked trying to enter zil_commit. This type of deadlock has not been
reported as of now.
o An indefinite wait in the unmount path caused by a znode "falling through
the cracks" in inactive+reclaim. This would happen if the znode is unlinked
while its vnode is still active.
To Do: pass locking flags parameter to zfs_zget, so that the zfs-vfs
glue code doesn't have to re-lock a vnode but could ask for proper locking
from the very start. This would also allow for the higher level code to
obtain a doomed vnode when it is expected/requested. Or to avoid blocking
when it is not allowed (see zil_commit example above).
ffs_vgetf seems like a good source of inspiration.
Tested by: Willem Jan Withagen <wjw@digiware.nl>
MFC after: 6 weeks
... otherwise zfs_getpages would mostly be called with one page at a time.
It is expected that ZFS VOP_BMAP is only called from vnode_pager_haspage.
Since ZFS files can have variable block sizes and also because we don't
really know if any given blocks are consecutive, we can not really report
any additional blocks behind or ahead of a given block. Since physical
block numbers do not make sense for ZFS, we do not do any real translation
and thus pass back blk = lblk. The net effect is that vnode_pager_haspage
knows that the block exists and that the pages backed by the block can be
accessed. vnode_pager_haspage may be wrong about the exact count of the
pages backed by the block, because of a variable block size, which
vnode_pager_haspage doesn't really know - it only knows max block size in
a filesystem. So pages from multiple blocks can be passed to zfs_getpages,
but that is expected and correctly handled.
vnode_pager should not call zfs_bmap for any other reason, because ZFS
implements VOP_PUTPAGES and thus vnode_pager_generic_getpages is not used.
vfs_cluster code vfs_bio code should not be called for ZFS, because ZFS does
not use buffer cache layer.
Also, ZFS does not use vn_bmap_seekhole, it has its prviate mechanism for
working with holes.
The above list should cover all the current calls to VOP_BMAP.
Reviewed by: kib
MFC after: 6 weeks
