kcmp(2): implement for vnode files

Reviewed by: brooks, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D43518

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 $FreeBSD$: one-line .h pattern

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

Revert "VFS: Remove VV_READLINK flag" and "fdescfs: improve linrdlnk mount option"

This reverts commits 4a402dfe0bc44770c9eac6e58a501e4805e29413 and
3bffa2262328e4ff1737516f176107f607e7bc76.

The fi

Revert "VFS: Remove VV_READLINK flag" and "fdescfs: improve linrdlnk mount option"

This reverts commits 4a402dfe0bc44770c9eac6e58a501e4805e29413 and
3bffa2262328e4ff1737516f176107f607e7bc76.

The fix will be implemented in somewhat different manner. The semantic
adjustment is incompatible with linuxolator expectations.

Reported and reviewed by: dchagin
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D40969

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vfs: use __enum_uint8 for vtype and vstate

This whacks hackery around only reading v_type once.

Bump __FreeBSD_version to 1400093

vfs: list enums on separate lines

Requested by: kib

VFS: Remove VV_READLINK flag

since its only reason to exist is removed.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://revie

VFS: Remove VV_READLINK flag

since its only reason to exist is removed.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D40700

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vfs: Rename vfs_emptydir() to vn_dir_check_empty()

No functional change. While here, adapt comments to style(9).

Reviewed by: kib
MFC after: 1 week

vfs: vn_dir_next_dirent(): Simplify interface and harden

Simplify the old interface (one less argument, simpler termination test)
and add documentation about it. Add more sanity checks (mostly under

vfs: vn_dir_next_dirent(): Simplify interface and harden

Simplify the old interface (one less argument, simpler termination test)
and add documentation about it. Add more sanity checks (mostly under
INVARIANTS, but also in the general case to prevent infinite
loops). Drop the explicit test on minimum directory entry size (without
INVARIANTS).

Deal with the impacts in callers (dirent_exists() and vop_stdvptocnp()).
dirent_exists() has been simplified a bit, preserving the exact same
semantics but for the return code whose meaning has been reversed (0 now
means the entry exists, ENOENT that it doesn't and other values are
genuine errors). While here, suppress gratuitous casts of malloc return
values.

vn_dir_next_dirent() has been tested by a 'make -j4 buildkernel' with a
temporary modification to the VFS cache causing vn_vptocnp() to always
call VOP_VPTOCNP() and finally vop_stdvptocnp() (observed with temporary
debug counters).

Export new _GENERIC_MINDIRSIZ and _GENERIC_MAXDIRSIZ on __BSD_VISIBLE,
and GENERIC_MINDIRSIZ and GENERIC_MAXDIRSIZ on _KERNEL.

Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D39764

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vfs: Export get_next_dirent() as vn_dir_next_dirent()

Move internal-to-'vfs_default.c' get_next_dirent() to 'vfs_vnops.c' and
export it for use by other parts of the VFS. This is a preparatory
chang

vfs: Export get_next_dirent() as vn_dir_next_dirent()

Move internal-to-'vfs_default.c' get_next_dirent() to 'vfs_vnops.c' and
export it for use by other parts of the VFS. This is a preparatory
change for using it in vfs_emptydir().

No functional change.

Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D39755

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DEBUG_VFS_LOCKS: use witness if available

The assert_vop_locked messages are ignored, and file/line information
is not too useful. Fixing this without changing both witness and VFS
asserts KPIs is n

DEBUG_VFS_LOCKS: use witness if available

The assert_vop_locked messages are ignored, and file/line information
is not too useful. Fixing this without changing both witness and VFS
asserts KPIs is not possible.

Reviewed by: markj (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39464

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vn_lock_pair(): allow to request shared locking

If either of vnodes is shared locked, lock must not be recursed.

Requested by: rmacklem
Reviewed by: markj, rmacklem
Tested by: pho
Sponsored by: The

vn_lock_pair(): allow to request shared locking

If either of vnodes is shared locked, lock must not be recursed.

Requested by: rmacklem
Reviewed by: markj, rmacklem
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39444

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vfs: more informative panic for missing fplookup ops

vfs: validate that vop vectors provide all or none fplookup vops

In order to prevent later susprises.

vfs: retire KERN_VNODE

It got disabled in 2003:

commit acb18acfec97aa7fe26ff48f80a5c3f89c9b542d
Author: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Sun Feb 23 18:09:05 2003 +0000

Bracket the k

vfs: retire KERN_VNODE

It got disabled in 2003:

commit acb18acfec97aa7fe26ff48f80a5c3f89c9b542d
Author: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Sun Feb 23 18:09:05 2003 +0000

Bracket the kern.vnode sysctl in #ifdef notyet because it results
in massive locking issues on diskless systems.

It is also not clear that this sysctl is non-dangerous in its
requirements for locked down memory on large RAM systems.

There does not seem to be practical use for it and the disabled routine
does not work anyway.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D39127

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vfs: add vn_getsize

getattr is very expensive and in important cases only gets called to get
the size. This can be optimized with a dedicated routine which obtains
that statistic.

As a step towards

vfs: add vn_getsize

getattr is very expensive and in important cases only gets called to get
the size. This can be optimized with a dedicated routine which obtains
that statistic.

As a step towards that goal make size-only consumers use a dedicated
routine.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D37885

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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: use designated initializers for the typename array

While here prefix with v for better consistency with the vnode stuff.

Reviewed by: kib (previous version)
Differential Revision: https://revi

vfs: use designated initializers for the typename array

While here prefix with v for better consistency with the vnode stuff.

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

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Add vn_path_to_global_path_hardlink

This is similar to vn_path_to_global_path but allows for regular files
which may not be present in the cache.

Reviewed by: mjg, kib
Tested by: pho

Add VV_CROSSLOCK vnode flag to avoid cross-mount lookup LOR

When a lookup operation crosses into a new mountpoint, the mountpoint
must first be busied before the root vnode can be locked. When a
fil

Add VV_CROSSLOCK vnode flag to avoid cross-mount lookup LOR

When a lookup operation crosses into a new mountpoint, the mountpoint
must first be busied before the root vnode can be locked. When a
filesystem is unmounted, the vnode covered by the mountpoint must
first be locked, and then the busy count for the mountpoint drained.
Ordinarily, these two operations work fine if executed concurrently,
but with a stacked filesystem the root vnode may in fact use the
same lock as the covered vnode. By design, this will always be
the case for unionfs (with either the upper or lower root vnode
depending on mount options), and can also be the case for nullfs
if the target and mount point are the same (which admittedly is
very unlikely in practice).

In this case, we have LOR. The lookup path holds the mountpoint
busy while waiting on what is effectively the covered vnode lock,
while a concurrent unmount holds the covered vnode lock and waits
for the mountpoint's busy count to drain.

Attempt to resolve this LOR by allowing the stacked filesystem
to specify a new flag, VV_CROSSLOCK, on a covered vnode as necessary.
Upon observing this flag, the vfs_lookup() will leave the covered
vnode lock held while crossing into the mountpoint. Employ this flag
for unionfs with the caveat that it can't be used for '-o below' mounts
until other unionfs locking issues are resolved.

Reported by: pho
Tested by: pho
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D35054

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cache: add cache_assert_no_entries

Add vn_rlimit_fsizex() and vn_rlimit_fsizex_res()

The vn_rlimit_fsizex() function:
- checks that the write does not exceed RLIMIT_FSIZE limit and fs
maximum supported file size
- truncates write l

Add vn_rlimit_fsizex() and vn_rlimit_fsizex_res()

The vn_rlimit_fsizex() function:
- checks that the write does not exceed RLIMIT_FSIZE limit and fs
maximum supported file size
- truncates write length if it exceeds the RLIMIT_FSIZE or max file size,
but there are some bytes to write
- sends SIGXFSZ if RLIMIT_FSIZE would be exceed otherwise

POSIX mandates the truncated write in case when some bytes can be
written but whole write request fails the RLIMIT_FSIZE check.

The function is supposed to be used from VOP_WRITE()s. Due to
pecularity in the VFS generic write syscall layer, uio_resid must
correctly reflect the written amount (noted by markj). Provide the dual
vn_rlimit_fsizex_res() function to correct uio_resid after the clamp
done in vn_rlimit_fsizex() on VOP_WRITE() return.

PR: 164793
Reviewed by: asomers, jah, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D36625

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Add vn_rlimit_trunc()

Reviewed by: asomers, jah, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D36625

vfs: indent V_VALID_FLAGS with a tab

Requested by: kib

vfs: introduce V_PCATCH to stop abusing PCATCH