sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl s

sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

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sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

vfs: add the concept of vnode state transitions

To quote from a comment above vput_final:
<quote>
* XXX Some filesystems pass in an exclusively locked vnode and strongly depend
* on the lock being h

vfs: add the concept of vnode state transitions

To quote from a comment above vput_final:
<quote>
* XXX Some filesystems pass in an exclusively locked vnode and strongly depend
* on the lock being held all the way until VOP_INACTIVE. This in particular
* happens with UFS which adds half-constructed vnodes to the hash, where they
* can be found by other code.
</quote>

As is there is no mechanism which allows filesystems to denote that a
vnode is fully initialized, consequently problems like the above are
only found the hard way(tm).

Add rudimentary support for state transitions, which in particular allow
to assert the vnode is not legally unlocked until its fate is decided
(either construction finishes or vgone is called to abort it).

The new field lands in a 1-byte hole, thus it does not grow the struct.

Bump __FreeBSD_version to 1400077

Reviewed by: kib (previous version)
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D37759

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nullfs: hash insertion without vnode lock upgrade

Use the hash lock to serialize instead.

This enables shared-locked ".." lookups.

Reviewed by: markj
Tested by: pho (previous version)
Differential

nullfs: hash insertion without vnode lock upgrade

Use the hash lock to serialize instead.

This enables shared-locked ".." lookups.

Reviewed by: markj
Tested by: pho (previous version)
Differential Revision: https://reviews.freebsd.org/D34466

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insmntque1(): remove useless arguments

Also remove once-used functions to clean up after failed insmntque1(),
which were destructor callbacks in previous life.

Reviewed by: markj
Tested by: pho
Spo

insmntque1(): remove useless arguments

Also remove once-used functions to clean up after failed insmntque1(),
which were destructor callbacks in previous life.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D34071

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Revert b58ca5df0bb7 ("vfs: remove the now unused insmntque1")

I was somehow convinced that insmntque calls insmntque1 with a NULL
destructor. Unfortunately this worked well enough to not immediately

Revert b58ca5df0bb7 ("vfs: remove the now unused insmntque1")

I was somehow convinced that insmntque calls insmntque1 with a NULL
destructor. Unfortunately this worked well enough to not immediately
blow up in simple testing.

Keep not using the destructor in previously patched filesystems though
as it avoids unnecessary casts.

Noted by: kib
Reported by: pho

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nullfs: ansify fs/nullfs/null_subr.c

nullfs: stop using insmntque1

It adds nothing of value over insmntque.

vfs: add v_irflag accessors

Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D27793

VMIO reads: enable for nullfs upper vnode if the lower vnode supports it.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D2

VMIO reads: enable for nullfs upper vnode if the lower vnode supports it.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D25968

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Fix up various vnode-related asserts which did not dump the used vnode

Fix a bug in r357199.

Around a generic call to null_nodeget(), there is nothing that would
prevent the unmount of the nullfs mp until we process to the
insmntque1() point. Calculate the VV_ROOT fla

Fix a bug in r357199.

Around a generic call to null_nodeget(), there is nothing that would
prevent the unmount of the nullfs mp until we process to the
insmntque1() point. Calculate the VV_ROOT flag after insmntque1() to
not access mp->mnt_data before we have an exclusively locked vnode
from this mount point on the mp vnode list.

Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Save lower root vnode in nullfs mnt data instead of upper.

Nullfs needs to know the root vnode of the lower fs during the
operation. Currently it caches the upper vnode of it, which is also
the roo

Save lower root vnode in nullfs mnt data instead of upper.

Nullfs needs to know the root vnode of the lower fs during the
operation. Currently it caches the upper vnode of it, which is also
the root of the nullfs mount. On unmount, nullfs calls vflush() with
rootrefs == 1, and aborts non-forced unmount if there are any more
vnodes instantiated during vflush(). This means that the reference to
the root vnode after failed non-forced unmount could be lost and
nullm_rootvp points to the freed memory.

Fix it by storing the reference for lower vnode instead, which is kept
intact during vflush(). nullfs_root() now instantiates the upper
vnode of lower root. Care about VV_ROOT flag in null_nodeget().

Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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vfs: introduce v_irflag and make v_type smaller

The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
part

vfs: introduce v_irflag and make v_type smaller

The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by: kib, jeff
Differential Revision: https://reviews.freebsd.org/D22715

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nullfs: locklessly check for entries in null_hashget

During random sampling over poudriere -j 104 over 10% of calls returned NULL.

nullfs: lock the vnode with LK_SHARED in null_vptocnp

null_nodeget which follows almost always finds the target vnode in the hash,
avoiding insmntque1 altogether. Should it be needed, it already che

nullfs: lock the vnode with LK_SHARED in null_vptocnp

null_nodeget which follows almost always finds the target vnode in the hash,
avoiding insmntque1 altogether. Should it be needed, it already checks if the
lock needs to be upgraded.

Reviewed by: kib
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20244

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sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

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Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

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Change the getnewvnode(9) tag for nullfs from "null" to "nullfs".
It's more consistent, and besides, the "null" alone looks weird.

MFC after: 1 month

Convert nullfs hash lock from a mutex to an rwlock.

- Fix nullfs vnode reference leak in nullfs_reclaim_lowervp(). The
null_hashget() obtains the reference on the nullfs vnode, which must
be dropped.

- Fix a wart which existed from the introduct

- Fix nullfs vnode reference leak in nullfs_reclaim_lowervp(). The
null_hashget() obtains the reference on the nullfs vnode, which must
be dropped.

- Fix a wart which existed from the introduction of the nullfs
caching, do not unlock lower vnode in the nullfs_reclaim_lowervp().
It should be innocent, but now it is also formally safe. Inform the
nullfs_reclaim() about this using the NULLV_NOUNLOCK flag set on
nullfs inode.

- Add a callback to the upper filesystems for the lower vnode
unlinking. When inactivating a nullfs vnode, check if the lower
vnode was unlinked, indicated by nullfs flag NULLV_DROP or VV_NOSYNC
on the lower vnode, and reclaim upper vnode if so. This allows
nullfs to purge cached vnodes for the unlinked lower vnode, avoiding
excessive caching.

Reported by: G??ran L??wkrantz <goran.lowkrantz@ismobile.com>
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

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The current default size of the nullfs hash table used to lookup the
existing nullfs vnode by the lower vnode is only 16 slots. Since the
default mode for the nullfs is to cache the vnodes, hash has

The current default size of the nullfs hash table used to lookup the
existing nullfs vnode by the lower vnode is only 16 slots. Since the
default mode for the nullfs is to cache the vnodes, hash has extremely
huge chains.

Size the nullfs hashtbl based on the current value of
desiredvnodes. Use vfs_hash_index() to calculate the hash bucket for a
given vnode.

Pointy hat to: kib
Diagnosed and reviewed by: peter
Tested by: peter, pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 5 days

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Fix reversed condition in the assertion.

Pointy hat to: kib
MFC after: 13 days

Add the "nocache" nullfs mount option, which disables the caching of
the free nullfs vnodes, switching nullfs behaviour to pre-r240285.
The option is mostly intended as the last-resort when higher pr

Add the "nocache" nullfs mount option, which disables the caching of
the free nullfs vnodes, switching nullfs behaviour to pre-r240285.
The option is mostly intended as the last-resort when higher pressure
on the vnode cache due to doubling of the vnode counts is not
desirable.

Note that disabling the cache costs more than 2x wall time in the
metadata-hungry scenarious. The default is "cache".

Tested and benchmarked by: pho (previous version)
MFC after: 2 weeks

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Remove the check and panic for an impossible condition. The NULL
lowervp vnode v_vnlock would cause panic due to NULL pointer
dereference much earlier.

MFC after: 1 week