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/

deadfs: consistently return EOPNOTSUPP for fplookup vops

vn_open(): If the vnode is reclaimed during open(2), do not return error.

Most future operations on the returned file descriptor will fail
anyway, and application should be ready to handle that fail

vn_open(): If the vnode is reclaimed during open(2), do not return error.

Most future operations on the returned file descriptor will fail
anyway, and application should be ready to handle that failures. Not
forcing it to understand the transient failure mode on open, which is
implementation-specific, should make us less special without loss of
reporting of errors.

Suggested by: chs
Reviewed by: chs, mckusick
Tested by: pho
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

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cache: add symlink support to lockless lookup

Reviewed by: kib (previous version)
Tested by: pho (previous version)
Differential Revision: https://reviews.freebsd.org/D27488

cache: fix vexec panic when racing against vgone

Use of dead_vnodeops would result in a panic instead of returning the intended
EOPNOTSUPP error.

While here make sure to abort, not just try to retu

cache: fix vexec panic when racing against vgone

Use of dead_vnodeops would result in a panic instead of returning the intended
EOPNOTSUPP error.

While here make sure to abort, not just try to return a partial result.
The former allows the regular lookup to restart from scratch, while the latter
makes it stuck with an unusable vnode.

Reported by: kevans

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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;

Revie

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

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Switch to use shared vnode locks for text files during image activation.

kern_execve() locks text vnode exclusive to be able to set and clear
VV_TEXT flag. VV_TEXT is mutually exclusive with the v_w

Switch to use shared vnode locks for text files during image activation.

kern_execve() locks text vnode exclusive to be able to set and clear
VV_TEXT flag. VV_TEXT is mutually exclusive with the v_writecount > 0
condition.

The change removes VV_TEXT, replacing it with the condition
v_writecount <= -1, and puts v_writecount under the vnode interlock.
Each text reference decrements v_writecount. To clear the text
reference when the segment is unmapped, it is recorded in the
vm_map_entry backed by the text file as MAP_ENTRY_VN_TEXT flag, and
v_writecount is incremented on the map entry removal

The operations like VOP_ADD_WRITECOUNT() and VOP_SET_TEXT() check that
v_writecount does not contradict the desired change. vn_writecheck()
is now racy and its use was eliminated everywhere except access.
Atomic check for writeability and increment of v_writecount is
performed by the VOP. vn_truncate() now increments v_writecount
around VOP_SETATTR() call, lack of which is arguably a bug on its own.

nullfs bypasses v_writecount to the lower vnode always, so nullfs
vnode has its own v_writecount correct, and lower vnode gets all
references, since object->handle is always lower vnode.

On the text vnode' vm object dealloc, the v_writecount value is reset
to zero, and deadfs vop_unset_text short-circuit the operation.
Reclamation of lowervp always reclaims all nullfs vnodes referencing
lowervp first, so no stray references are left.

Reviewed by: markj, trasz
Tested by: mjg, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D19923

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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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Style changes for deadfs:
- ANSIfy VOPs.
- Remove trivial comments.
- Remove ARGSUSED.
- Remove copies of the vop_XXX_args structure definitions in comments.

Sponsored by: The FreeBSD Foundation
MFC

Style changes for deadfs:
- ANSIfy VOPs.
- Remove trivial comments.
- Remove ARGSUSED.
- Remove copies of the vop_XXX_args structure definitions in comments.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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When vnode bypass cannot be performed on the cdev file descriptor for
read/write/poll/ioctl, call standard vnode filedescriptor fop. This
restores the special handling for terminals by calling the d

When vnode bypass cannot be performed on the cdev file descriptor for
read/write/poll/ioctl, call standard vnode filedescriptor fop. This
restores the special handling for terminals by calling the deadfs VOP,
instead of always returning ENXIO for destroyed devices or revoked
terminals.

Since destroyed (and not revoked) device would use devfs_specops VOP
vector, make dead_read/write/poll non-static and fill VOP table with
pointers to the functions, to instead of VOP_PANIC.

Noted and reviewed by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Change the deadfs poll VOP to return POLLIN|POLLRDNORM if the caller
is interested in i/o state. Return POLLNVAL for invalid bits, similar
to poll_no_poll(). Note that POLLOUT must not be returned,

Change the deadfs poll VOP to return POLLIN|POLLRDNORM if the caller
is interested in i/o state. Return POLLNVAL for invalid bits, similar
to poll_no_poll(). Note that POLLOUT must not be returned, since
POLLHUP is set.

Noted and reviewed by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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The deadfs VOPs for vop_ioctl and vop_bmap call itself recursively,
which is an elaborate way to cause kernel panic. Change the VOPs
implementation to return EBADF for a reclaimed vnode.

While the c

The deadfs VOPs for vop_ioctl and vop_bmap call itself recursively,
which is an elaborate way to cause kernel panic. Change the VOPs
implementation to return EBADF for a reclaimed vnode.

While the calls to vop_bmap should not reach deadfs, it is indeed
possible for vop_ioctl, because the VOP locking protocol is to pass
the vnode to VOP unlocked. The actual panic was observed when ioctl
was called on procfs filedescriptor which pointed to an exited
process.

Reported by: zont
Tested by: pho
MFC after: 1 week

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MFC r206093:
Add function vop_rename_fail(9) that performs needed cleanup for locks
and references of the VOP_RENAME(9) arguments. Use vop_rename_fail()
in deadfs_rename().

Add function vop_rename_fail(9) that performs needed cleanup for locks
and references of the VOP_RENAME(9) arguments. Use vop_rename_fail()
in deadfs_rename().

Tested by: Mikolaj Golub
MFC after: 1

Add function vop_rename_fail(9) that performs needed cleanup for locks
and references of the VOP_RENAME(9) arguments. Use vop_rename_fail()
in deadfs_rename().

Tested by: Mikolaj Golub
MFC after: 1 week

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Add a simple VOP_VPTOCNP implementation for deadfs which returns EBADF.

Reviewed by: arch
Approved by: kib

Below is slightly edited description of the LOR by Tor Egge:

--------------------------
[Deadlock] is caused by a lock order reversal in vfs_lookup(), where
[some] process is trying to lock a direct

Below is slightly edited description of the LOR by Tor Egge:

--------------------------
[Deadlock] is caused by a lock order reversal in vfs_lookup(), where
[some] process is trying to lock a directory vnode, that is the parent
directory of covered vnode) while holding an exclusive vnode lock on
covering vnode.

A simplified scenario:

root fs var fs
/ A / (/var) D
/var B /log (/var/log) E
vfs lock C vfs lock F

Within each file system, the lock order is clear: C->A->B and F->D->E

When traversing across mounts, the system can choose between two lock orders,
but everything must then follow that lock order:

L1: C->A->B
|
+->F->D->E

L2: F->D->E
|
+->C->A->B

The lookup() process for namei("/var") mixes those two lock orders:

VOP_LOOKUP() obtains B while A is held
vfs_busy() obtains a shared lock on F while A and B are held (follows L1,
violates L2)
vput() releases lock on B
VOP_UNLOCK() releases lock on A
VFS_ROOT() obtains lock on D while shared lock on F is held
vfs_unbusy() releases shared lock on F
vn_lock() obtains lock on A while D is held (violates L1, follows L2)

dounmount() follows L1 (B is locked while F is drained).

Without unmount activity, vfs_busy() will always succeed without blocking
and the deadlock isn't triggered (the system behaves as if L2 is followed).

With unmount, you can get 4 processes in a deadlock:

p1: holds D, want A (in lookup())
p2: holds shared lock on F, want D (in VFS_ROOT())
p3: holds B, want drain lock on F (in dounmount())
p4: holds A, want B (in VOP_LOOKUP())

You can have more than one instance of p2.

The reversal was introduced in revision 1.81 of src/sys/kern/vfs_lookup.c and
MFCed to revision 1.80.2.1, probably to avoid a cascade of vnode locks when nfs
servers are dead (VFS_ROOT() just hangs) spreading to the root fs root vnode.

- Tor Egge

To fix the LOR, ups@ noted that when crossing the mount point, ni_dvp
is actually not used by the callers of namei. Thus, placeholder deadfs
vnode vp_crossmp is introduced that is filled into ni_dvp.

Idea by: ups
Reviewed by: tegge, ups, jeff, rwatson (mac interaction)
Tested by: Peter Holm
MFC after: 2 weeks

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- Deadfs should not use the std GETWRITEMOUNT routine. Add one that always
returns NULL.

MFC After: 1 week

- Deadfs may now use the standard vop lock, get rid of dead_lock().
- We no longer have to take the XLOCK state into consideration in any
routines.

Sponsored by: Isilon Systems, Inc.

Introduce vx_wait{l}() and use it instead of home-rolled versions.

Whitespace in vop_vector{} initializations.

Change the generated VOP_ macro implementations to improve type checking
and KASSERT coverage.

After this check there is only one "nasty" cast in this code but there
is a KASSERT to protect against

Change the generated VOP_ macro implementations to improve type checking
and KASSERT coverage.

After this check there is only one "nasty" cast in this code but there
is a KASSERT to protect against the wrong argument structure behind
that cast.

Un-inlining the meat of VOP_FOO() saves 35kB of text segment on a typical
kernel with no change in performance.

We also now run the checking and tracing on VOP's which have been layered
by nullfs, umapfs, deadfs or unionfs.

Add new (non-inline) VOP_FOO_AP() functions which take a "struct
foo_args" argument and does everything the VOP_FOO() macros
used to do with checks and debugging code.

Add KASSERT to VOP_FOO_AP() check for argument type being
correct.

Slim down VOP_FOO() inline functions to just stuff arguments
into the struct foo_args and call VOP_FOO_AP().

Put function pointer to VOP_FOO_AP() into vop_foo_desc structure
and make VCALL() use it instead of the current offsetoff() hack.

Retire vcall() which implemented the offsetoff()

Make deadfs and unionfs use VOP_FOO_AP() calls instead of
VCALL(), we know which specific call we want already.

Remove unneeded arguments to VCALL() in nullfs and umapfs bypass
functions.

Remove unused vdesc_offset and VOFFSET().

Generally improve style/readability of the generated code.

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/* -> /*- for copyright notices, minor format tweaks as necessary

Back when VOP_* was introduced, we did not have new-style struct
initializations but we did have lofty goals and big ideals.

Adjust to more contemporary circumstances and gain type checking.

Repla

Back when VOP_* was introduced, we did not have new-style struct
initializations but we did have lofty goals and big ideals.

Adjust to more contemporary circumstances and gain type checking.

Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.

Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.

Give coda correct prototypes and function definitions for
all vop_()s.

Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.

Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.

Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.

Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.

Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.

Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)

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