devfs_allocv(): style

(cherry picked from commit 6d79564fe341c8dbf09405cae1a0a76460aaf8aa)

cdevpriv(9): add iterator

(cherry picked from commit d3efbe0132b24e8660df836905cda7662f85a154)

kcmp(2): implement for devfs files

(cherry picked from commit 5c41d888de1aba0e82531fb6df4cc3b6989d37bd)

devfs: add integrity asserts for cdevp_list

It's possible for misuse of cdev KPIs or for bugs in devfs itself to
result in e.g. a cdev object's container being freed while still on the
global list u

devfs: add integrity asserts for cdevp_list

It's possible for misuse of cdev KPIs or for bugs in devfs itself to
result in e.g. a cdev object's container being freed while still on the
global list used to populate each devfs mount; see PR 273418 for a
recent example.

Since a node may be marked inactive well before it is reaped from the
list, add a new flag solely to track list membership, and employ it in
some basic list integrity assertions to catch bad actors.

Discussed with: kib, mjg

(cherry picked from commit 67864268da53b792836f13be10299de8cd62997e)

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

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

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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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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vfs: always retain path buffer after lookup

This removes some of the complexity needed to maintain HASBUF and
allows for removing injecting SAVENAME by filesystems.

Reviewed by: kib (previous versi

vfs: always retain path buffer after lookup

This removes some of the complexity needed to maintain HASBUF and
allows for removing injecting SAVENAME by filesystems.

Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D36542

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Retire clone_drain_lock

It is only ever xlocked in drain_dev_clone_events and the only consumer of
that routine does not need it -- eventhandler code already makes sure the
relevant callback is no l

Retire clone_drain_lock

It is only ever xlocked in drain_dev_clone_events and the only consumer of
that routine does not need it -- eventhandler code already makes sure the
relevant callback is no longer running.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D36268

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fs: fix a few common typos in source code comments

- s/quadradically/quadratically/
- s/persistant/persistent/

Obtained from: NetBSD
MFC after: 3 days

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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devfs: stop using insmntque1

It adds nothing of value over insmntque.

vfs: add vop_stdadd_writecount_nomsync

This avoids needing to inspect the mount point every time.

Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D33125

vfs: remove thread argument from VOP_STAT

and fo_stat.

vfs: remove cn_thread

It is always curthread.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D32453

devfs: Avoid comparison with an uninitialized var in devfs_fp_check()

devvn_refthread() will initialize *devp only if it succeeds, so check for
success before comparing with fp->f_data. Other devvn

devfs: Avoid comparison with an uninitialized var in devfs_fp_check()

devvn_refthread() will initialize *devp only if it succeeds, so check for
success before comparing with fp->f_data. Other devvn_refthread()
callers are careful to do this.

Reported by: KMSAN
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30068

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devfs: fix use count leak when using TIOCSCTTY

by matching devfs_ctty_ref

Fixes: 3b44443626603f65 ("devfs: rework si_usecount to track opens")

devfs: rework si_usecount to track opens

This removes a lot of special casing from the VFS layer.

Reviewed by: kib (previous version)
Tested by: pho (previous version)
Differential Revision: https:

devfs: rework si_usecount to track opens

This removes a lot of special casing from the VFS layer.

Reviewed by: kib (previous version)
Tested by: pho (previous version)
Differential Revision: https://reviews.freebsd.org/D25612

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devfs: save on spurious relocking for devfs_populate

Tested by: pho

devfs: use cheaper lockmgr entry points

Tested by: pho

devfs: use vget_prep/vget_finish

Tested by: pho

vfs: remove the obsolete privused argument from vaccess

This brings argument count down to 6, which is passable without the
stack on amd64.

devfs: fix a vnode use-after-free in devfs_ioctl

The vnode to be replaced was read with a shared lock, meaning 2 racing threads
can find the same one.

While here clean it up a little bit.

vfs: track sequential reads and writes separately

For software like PostgreSQL and SQLite that sometimes reads sequentially
while also writing sequentially some distance behind with interleaved
sysc

vfs: track sequential reads and writes separately

For software like PostgreSQL and SQLite that sometimes reads sequentially
while also writing sequentially some distance behind with interleaved
syscalls on the same fd, performance is better on UFS if we do
sequential access heuristics separately for reads and writes.

Patch originally by Andrew Gierth in 2008, updated and proposed by me with
his permission.

Reviewed by: mjg, kib, tmunro
Approved by: mjg (mentor)
Obtained from: Andrew Gierth <[email protected]>
Differential Revision: https://reviews.freebsd.org/D25024

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