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

Remove /^#include\s+<sys/cdefs.h>.*$\n\s+__FBSDID\("\$FreeBSD\$"\);\n/

spdx: The BSD-2-Clause-NetBSD identifier is obsolete, drop -NetBSD

The SPDX folks have obsoleted the BSD-2-Clause-NetBSD 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

tmpfs: add missing vop_fplookup ops to tmpfs_fifoop_entries

Reported by: gbe
PR: 270917

tmpfs: add vop_stdadd_writecount_nomsync to fifo vnode ops

Reported by: yasu
Fixes: 3ffcfa599e29686c ("vfs: add vop_stdadd_writecount_nomsync")

tmpfs: restore atime updates for reads from page cache.

Split TMPFS_NODE_ACCCESSED bit into dedicated byte that can be updated
atomically without locks or (locked) atomics.

tn_update_getattr() change also contains unrelated bug fix.

Reported by: lwhsu
PR: 249362
Reviewed by: markj (previous version)
Discussed with: mjg
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D26451

vfs: flatten vop vectors

This eliminates the following loop from all VOP calls:

while(vop != NULL && \
vop->vop_spare2 == NULL && vop->vop_bypass == NULL)
vop = vop->vop_default;

Reviewed by: jeff
Tesetd by: pho
Differential Revision: https://reviews.freebsd.org/D22738

tmpfs: ignore tmpfs_set_status() if mount point is read-only.

In particular, this fixes atimes still changing for ro tmpfs.
tmpfs_set_status() gains tmpfs_mount * argument.

Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D19737

Rework pathconf handling for FIFOs.

On the one hand, FIFOs should respect other variables not supported by
the fifofs vnode operation (such as _PC_NAME_MAX, _PC_LINK_MAX, etc.).
These values are fs-specific and must come from a fs-specific method.
On the other hand, filesystems that support FIFOs are required to
support _PC_PIPE_BUF on directory vnodes that can contain FIFOs.
Given this latter requirement, once the fs-specific VOP_PATHCONF
method supports _PC_PIPE_BUF for directories, it is also suitable for
FIFOs permitting a single VOP_PATHCONF method to be used for both
FIFOs and non-FIFOs.

To that end, retire all of the FIFO-specific pathconf methods from
filesystems and change FIFO-specific vnode operation switches to use
the existing fs-specific VOP_PATHCONF method. For fifofs, set it's
VOP_PATHCONF to VOP_PANIC since it should no longer be used.

While here, move _PC_PIPE_BUF handling out of vop_stdpathconf() so that
only filesystems supporting FIFOs will report a value. In addition,
only report a valid _PC_PIPE_BUF for directories and FIFOs.

Discussed with: bde
Reviewed by: kib (part of a larger patch)
MFC after: 1 month
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D12572

Fix file missed in r326607.

sys/fs: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

Remove unused header.

Use tmpfs_print for tmpfs FIFOs.

Reviewed by: kib (part of a larger patch)

Lock tmpfs node tn_status updates done under the shared vnode lock.

If tmpfs vnode is only shared locked, tn_status field still needs
updates to note the access time modification. Use the same locking
scheme as for UFS, protect tn_status with the node interlock + shared
vnode lock.

Fix nearby style.

Noted and reviewed by: mjg
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Remove dead code.

Fifos overwrite file ops vector, and fifo VOP_KQFILTER is VOP_PANIC().

Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Remove code separator lines which do not conform to style(9).

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Reflect license change of NetBSD code.

Obtained from: NetBSD
MFC after: 3 days

Space/style cleanups after last set of commits.

Approved by: re (tmpfs blanket)

Staticify most of fifo/vn operations, they should not
be directly exposed outside.

Approved by: re (tmpfs blanket)

MFp4: Add tmpfs, an efficient memory file system.

Please note that, this is currently considered as an
experimental feature so there could be some rough
edges. Consult http://wiki.freebsd.org/TMPFS for
more information.

For now, connect tmpfs to build on i386 and amd64
architectures only. Please let us know if you have
success with other platforms.

This work was developed by Julio M. Merino Vidal
for NetBSD as a SoC project; Rohit Jalan ported it
from NetBSD to FreeBSD. Howard Su and Glen Leeder
are worked on it to continue this effort.

Obtained from: NetBSD via p4
Submitted by: Howard Su (with some minor changes)
Approved by: re (kensmith)