The current code is written on top of GFS, a library with the generic
support for writing filesystems, which was ported from illumos.
Because of significant differences between illumos VFS and FreeBSD
VFS models, both the GFS and zfsctl code were heavily modified to
work on FreeBSD. Nonetheless, they still contain quite a few ugly
hacks and bugs.
This is a reimplementation of the zfsctl code where the VFS-specific
bits are written from scratch and only the code that interacts with
the rest of ZFS is reused.
Some highlights.
We use two types of nodes, static and on-demand. The static nodes
are used for permanent directories like .zfs, .zfs/snapshot, etc. The
on-demand nodes are used for ephemeral directories that act as snapshot
mount points.
Initially only static nodes are created. Their vnodes are instantiated
when they are looked up. The on-demand nodes and vnodes are instantiated
as needed and the nodes are destroyed as soon as the corresponding
vnodes are reclaimed.
We also try very hard to ensure that uncovered snapshot vnodes do not
linger. They are supposed to become inactive as soon as they are
uncovered and we try to recycle them immediately.
When a filesystem is unmounted all snapshots under .zfs are unmounted
first, then all vnodes are flushed and finally the static .zfs nodes
are destroyed.
There are some changes outside of zfsctl code too.
z_ctldir is never used directly (as it is an opaque pointer),
zfsctl_root() has to be used instead. The function returns a locked
vnode now, so it accepts a lock flags parameter. The function can
also fail now, e.g. during force unmounting, whereas previously it
was infallible.
zfsctl_root_lookup() is retired, instead of it VOP_LOOKUP() on the .zfs
vnode (obtained with zfsctl_root) is used.
Some ideas are picked from an independent work by will.
Reviewed by: asomers, smh
MFC after: 1 month
Relnotes: maybe
Differential Revision: https://reviews.freebsd.org/D7421
It was a temporary change to ease an import of native atomic_cas primitives.
Instead, atomic_fcmpset was devised with different semantics. See r311168.
longer used. More precisely, they are always zero because the code that
decremented and incremented them no longer exists.
Bump __FreeBSD_version to mark this change.
Reviewed by: kib, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8583
not remove user-space visible fields from vm_cnt or all of the references to
cached pages from comments. Those changes will come later.)
Reviewed by: kib, markj
Tested by: pho
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8497
Our shim for Solaris random_get_bytes() uses read_random(), that looks
reasonable, since it guaranties reliably seeded random data. On the other
side Solaris random_get_pseudo_bytes() does not provide this guarantie,
and its original Solaris implementation is equivalent to our arc4rand(),
using software crypto without stressing slower hardware RNG.
ZFS POSIX Layer is originally written for Solaris VFS which is very
different from FreeBSD VFS. Most importantly many things that FreeBSD VFS
manages on behalf of all filesystems are implemented in ZPL in a different
way.
Thus, ZPL contains code that is redundant on FreeBSD or duplicates VFS
functionality or, in the worst cases, badly interacts / interferes
with VFS.
The most prominent problem is a deadlock caused by the lock order reversal
of vnode locks that may happen with concurrent zfs_rename() and lookup().
The deadlock is a result of zfs_rename() not observing the vnode locking
contract expected by VFS.
This commit removes all ZPL internal locking that protects parent-child
relationships of filesystem nodes. These relationships are protected
by vnode locks and the code is changed to take advantage of that fact
and to properly interact with VFS.
Removal of the internal locking allowed all ZPL dmu_tx_assign calls to
use TXG_WAIT mode.
Another victim, disputable perhaps, is ZFS support for filesystems with
mixed case sensitivity. That support is not provided by the OS anyway,
so in ZFS it was a buch of dead code.
To do:
- replace ZFS_ENTER mechanism with VFS managed / visible mechanism
- replace zfs_zget with zfs_vget[f] as much as possible
- get rid of not really useful now zfs_freebsd_* adapters
- more cleanups of unneeded / unused code
- fix / replace .zfs support
PR: 209158
Reported by: many
Tested by: many (thank you all!)
MFC after: 5 days
Sponsored by: HybridCluster / ClusterHQ
Differential Revision: https://reviews.freebsd.org/D6533
mp_maxid or CPU_FOREACH() as appropriate. This fixes a number of places in
the kernel that assumed CPU IDs are dense in [0, mp_ncpus) and would try,
for example, to run tasks on CPUs that did not exist or to allocate too
few buffers on systems with sparse CPU IDs in which there are holes in the
range and mp_maxid > mp_ncpus. Such circumstances generally occur on
systems with SMT, but on which SMT is disabled. This patch restores system
operation at least on POWER8 systems configured in this way.
There are a number of other places in the kernel with potential problems
in these situations, but where sparse CPU IDs are not currently known
to occur, mostly in the ARM machine-dependent code. These will be fixed
in a follow-up commit after the stable/11 branch.
PR: kern/210106
Reviewed by: jhb
Approved by: re (glebius)
This apparently puts ARC back under the limits after the vnode pressure
rework in r291244, in particular due to the kmem exhaustion.
Based on patch by: mckusick
Reviewed by: avg, mckusick
Tested by: allanjude, madpilot
Sponsored by: The FreeBSD Foundation
Approved by: re (gjb)
This commit partially reverts r273641 which introduced the leak.
It did so to accomodate for some consumers of traverse() that expected
the starting vnode to stay as-is. But that introduced the leak in the
case when a mounted filesystem was found and its root vnode was
returned.
r299914 removed the troublesome consumers and now there is no reason to
keep the starting vnode. So, now the new rules are:
- if there is no mounted filesystem, then nothing is changed
- otherwise the starting vnode is always released
- the root vnode of the mounted filesystem is returned locked and
referenced in the case of success
MFC after: 5 weeks
X-MFC after: r299914
* Remove excessive references on a snapshot mountpoint vnode.
zfsctl_snapdir_lookup() called VN_HOLD() on a vnode returned from
zfsctl_snapshot_mknode() and the latter also had a call to VN_HOLD()
on the same vnode.
On top of that gfs_dir_create() already returns the vnode with the
use count of 1 (set in getnewvnode).
So there was 3 references on the vnode.
* mount_snapshot() should keep a reference to a covered vnode.
That reference is owned by the mountpoint (mounted snapshot filesystem).
* Remove cryptic manipulations of a covered vnode in zfs_umount().
FreeBSD dounmount() already does the right thing and releases the covered
vnode.
PR: 207464
Reported by: dustinwenz@ebureau.com
Tested by: Howard Powell <hpowell@lighthouseinstruments.com>
MFC after: 3 weeks
On FreeBSD VFS_HOLD/VN_RELE were mapped to MNT_REF/MNT_REL that
manipulate mnt_ref. But the job of properly maintaining the reference
count is already automatically performed by insmntque(9) and
delmntque(9). So, in effect all ZFS vnodes referenced the corresponding
mountpoint twice.
That was completely harmless, but we want to be very explicit about what
FreeBSD VFS APIs are used, because illumos VFS_HOLD and FreeBSD MNT_REF
provide quite different guarantees with respect to the held vfs_t /
mountpoint. On illumos VFS_HOLD is sufficient to guarantee that
vfs_t.vfs_data stays valid. On the other hand, on FreeBSD MNT_REF does
*not* provide the same guarantee about mnt_data. We have to use
vfs_busy() to get that guarantee.
Thus, the calls to VFS_HOLD/VFS_RELE on vnode init and fini are removed.
VFS_HOLD calls are replaced with vfs_busy in the ioctl handlers.
And because vfs_busy has a richer interface that can not be dumbed down
in all cases it's better to explicitly use it rather than trying to mask
it behind VFS_HOLD.
This change fixes a panic that could result from a race between
zfs_umount() and zfs_ioc_rollback(). We observed a case where
zfsvfs_free() tried to destroy data that zfsvfs_teardown() was still
using. That happened because there was nothing to prevent unmounting of
a ZFS filesystem that was in between zfs_suspend_fs() and
zfs_resume_fs().
Reviewed by: kib, smh
MFC after: 3 weeks
Sponsored by: ClusterHQ
Differential Revision: https://reviews.freebsd.org/D2794
6672 arc_reclaim_thread() should use gethrtime() instead of ddi_get_lbolt()
6673 want a macro to convert seconds to nanoseconds and vice-versa
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Eli Rosenthal <eli.rosenthal@delphix.com>
illumos/illumos-gate@a8f6344fa0
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Prakash Surya <prakash.surya@delphix.com>
illumos/illumos-gate@97e8130957
This is the final step required allowing to compile and to run RISC-V
kernel and userland from HEAD.
RISC-V is a completely open ISA that is freely available to academia
and industry.
Thanks to all the people involved! Special thanks to Andrew Turner,
David Chisnall, Ed Maste, Konstantin Belousov, John Baldwin and
Arun Thomas for their help.
Thanks to Robert Watson for organizing this project.
This project sponsored by UK Higher Education Innovation Fund (HEIF5) and
DARPA CTSRD project at the University of Cambridge Computer Laboratory.
FreeBSD/RISC-V project home: https://wiki.freebsd.org/riscv
Reviewed by: andrew, emaste, kib
Relnotes: Yes
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D4982
- Add
nvlist_{add,get,take,move,exists,free}_{number,bool,string,nvlist,
descriptor} functions.
- Add support for (un)packing arrays.
- Add the nvl_array_next field to the nvlist structure.
If an array is added by the nvlist_{move,add}_nvlist_array function
this field will contains next element in the array.
- Add the nitems field to the nvpair and nvpair_header structure.
This field contains number of elements in the array.
- Add special flag (NV_FLAG_IN_ARRAY) which is set if nvlist is a part of
an array.
- Add special type (NV_TYPE_NVLIST_ARRAY_NEXT).This type is used only
on packing/unpacking.
- Add new API for traversing arrays (nvlist_get_array_next).
- Add the nvlist_get_pararr function which combines the
nvlist_get_array_next and nvlist_get_parent functions. If nvlist is in
the array it will return next element from array. If nvlist is last
element in array or it isn't in array it will return his
container (parent). This function should simplify traveling over nvlist.
- Add tests for new features.
- Add documentation for new functions.
- Add my copyright.
- Regenerate the sys/cddl/compat/opensolaris/sys/nvpair.h file.
PR: 191083
Reviewed by: allanjude (doc)
Approved by: pjd (mentor)
arc_state_t stats and differentiate between "data" and "metadata"
Reviewed by: Basil Crow <basil.crow@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Bayard Bell <bayard.bell@nexenta.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Prakash Surya <prakash.surya@delphix.com>
illumos/illumos-gate@4076b1bf41
This change refactors the existing create_thread() function to be more
generic. It replaces almost all of its arguments by a callback that can
be used to extract the thread ID and copy it out to the right place, but
also to perform additional initialization steps, such as setting the
trapframe. This also makes the difference between thr_new() and
thr_create() more clear in my opinion.
This function is going to be used by the CloudABI compatibility layer.
It looks like the OpenSolaris compatibility framework already provides a
function called thread_create(). Rename this function to
do_thread_create() and use a macro to deal with the namespacing
conflict. A similar approach is already used for thread_exit().
MFC after: 1 month
Previously several places were doing it on its own, partially
incorrectly (e.g. without the filedesc locked) or even actively harmful
by populating jdir or assigning rootvnode without vrefing it.
Reviewed by: kib
Currently there is no good reason to mangle the userland API.
The change was introduced in eac1d566b46edef765754203bef22c75c1699966,
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
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
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
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
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
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
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
nanouptime() instead of getnanouptime(). nanouptime(9) provides more
precise result at expense of being slower.
In r269223, gethrtime() is used as creation time of dbuf, which in turn
acts as portion of lookup key to maintain AVL invariant where there can
not be duplicate items. Before this change, gethrtime() have preferred
better execution time by sacrificing precision, which may lead to panic
on busy systems with:
panic: avl_find() succeeded inside avl_add()
Reported by: allanjude, mav
PR: kern/192284
MFC after: 11 days
X-MFC-with: r269223
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
