vfs/procfs: Add kqueue support

This patch is mostly derived from tmpfs.

With kqueue support implemented, poll() now works with the files on this
pseudo filesystem. For example, poll() would report

vfs/procfs: Add kqueue support

This patch is mostly derived from tmpfs.

With kqueue support implemented, poll() now works with the files on this
pseudo filesystem. For example, poll() would report POLLIN instead of
timing out, and this makes less(1) work correctly.

Reviewed-by: dillon

show more ...

vfs/procfs: Whitespace and style fixes

kernel - Normalize the vx_*() vnode interface

* The vx_*() vnode interface is used for initial allocations, reclaims,
and terminations.

Normalize all use cases to prevent the mixing together of

kernel - Normalize the vx_*() vnode interface

* The vx_*() vnode interface is used for initial allocations, reclaims,
and terminations.

Normalize all use cases to prevent the mixing together of the vx_*()
API and the vn_*() API. For example, vx_lock() should not be paired
with vn_unlock(), and so forth.

* Integrate an update-counter mechanism into the vx_*() API, assert
reasonability.

* Change vfs_cache.c to use an int update counter instead of a long.
The vfs_cache code can't quite use the spin-lock update counter API
yet.

Use proper atomics for load and store.

* Implement VOP_GETATTR_QUICK, meant to be a 'quick' version of
VOP_GETATTR() that only retrieves information related to permissions
and ownership. This will be fast-pathed in a later commit.

* Implement vx_downgrade() to convert an exclusive vx_lock into an
exclusive vn_lock (for vnodes). Adjust all use cases in the
getnewvnode() path.

* Remove unnecessary locks in tmpfs_getattr() and don't use
any in tmpfs_getattr_quick().

* Remove unnecessary locks in hammer2_vop_getattr() and don't use
any in hammer2_vop_getattr_quick()

show more ...

kernel - Fix first-lwp access race vs process creation

* It is possible for a process to be looked up before its primary
lwp is installed. Make sure this doesn't crash the kernel.

kernel: Cleanup <sys/uio.h> issues.

The iovec_free() inline very complicates this header inclusion. The
NULL check is not always seen from <sys/_null.h>. Luckily only three
kernel sources needs

kernel: Cleanup <sys/uio.h> issues.

The iovec_free() inline very complicates this header inclusion. The
NULL check is not always seen from <sys/_null.h>. Luckily only three
kernel sources needs it: kern_subr.c, sys_generic.c and uipc_syscalls.c.
Also just a single dev/drm source makes use of 'struct uio'.
* Include <sys/uio.h> explicitly first in drm_fops.c to avoid kfree()
macro override in drm compat layer.
* Use <sys/_uio.h> where only enums and struct uio is needed, but ensure
that userland will not include it for possible later <sys/user.h> use.
* Stop using <sys/vnode.h> as shortcut for uiomove*() prototypes. The
uiomove*() family functions possibly transfer data across kernel/user
space boundary. This header presence explicitly mark sources as such.
* Prefer to add <sys/uio.h> after <sys/systm.h>, but before <sys/proc.h>
and definitely before <sys/malloc.h> (except for 3 mentioned sources).
This will allow to remove <sys/malloc.h> from <sys/uio.h> later on.
* Adjust <sys/user.h> to use component headers instead of <sys/uio.h>.

While there, use opportunity for a minimal whitespace cleanup.

No functional differences observed in compiler intermediates.

show more ...

kernel: Remove numerous #include <sys/thread2.h>.

Most of them were added when we converted spl*() calls to
crit_enter()/crit_exit(), almost 14 years ago. We can now
remove a good chunk of them agai

kernel: Remove numerous #include <sys/thread2.h>.

Most of them were added when we converted spl*() calls to
crit_enter()/crit_exit(), almost 14 years ago. We can now
remove a good chunk of them again for where crit_*() are
no longer used.

I had to adjust some files that were relying on thread2.h
or headers that it includes coming in via other headers
that it was removed from.

show more ...

kernel - Fix SMP race in procfs

* procfs was not locking its pid hash table. Implement a per-slot
spinlock. The hash is populated only for pid directories that are
pushed into (e.g. ls /proc/<

kernel - Fix SMP race in procfs

* procfs was not locking its pid hash table. Implement a per-slot
spinlock. The hash is populated only for pid directories that are
pushed into (e.g. ls /proc/<pid> vs ls /proc).

* Fixes a fairly rare crash that can only occur when procfs is used
heavily.

show more ...

procfs - Fix blocked lock condition

* Two procfs races can result in a lock being blocked forever. Rip out
the old single-variable global procfs lock and per-node lock and replace
with a normal

procfs - Fix blocked lock condition

* Two procfs races can result in a lock being blocked forever. Rip out
the old single-variable global procfs lock and per-node lock and replace
with a normal lockmgr lock.

* The original lock existed from a time when all of procfs was wrapped with
a global lock. This is no longer the case.

show more ...

kernel - proc_token removal pass stage 1/2

* Remove proc_token use from all subsystems except kern/kern_proc.c.

* The token had become mostly useless in these subsystems now that process
locking

kernel - proc_token removal pass stage 1/2

* Remove proc_token use from all subsystems except kern/kern_proc.c.

* The token had become mostly useless in these subsystems now that process
locking is more fine-grained. Do the final wipe of proc_token except for
allproc/zombproc list use in kern_proc.c

show more ...

kernel - Rewrite vnode ref-counting code to improve performance

* Rewrite the vnode ref-counting code and modify operation to not
immediately VOP_INACTIVE a vnode when its refs drops to 0. By
d

kernel - Rewrite vnode ref-counting code to improve performance

* Rewrite the vnode ref-counting code and modify operation to not
immediately VOP_INACTIVE a vnode when its refs drops to 0. By
doing so we avoid cycling vnodes through exclusive locks when
temporarily accessing them (such as in a path lookup). Shared
locks can be used throughout.

* Track active/inactive vnodes a bit differently, keep track of
the number of vnodes that are still active but have zero refs,
and rewrite the vnode freeing code to use the new statistics
to deactivate cached vnodes.

show more ...

Correct BSD License clause numbering from 1-2-4 to 1-2-3.

Apparently everyone's doing it:
http://svnweb.freebsd.org/base?view=revision&revision=251069

Submitted-by: "Eitan Adler" <lists at eitanadl

Correct BSD License clause numbering from 1-2-4 to 1-2-3.

Apparently everyone's doing it:
http://svnweb.freebsd.org/base?view=revision&revision=251069

Submitted-by: "Eitan Adler" <lists at eitanadler.com>

show more ...

Remove advertising clause from all that isn't contrib or userland bin.

By: Eitan Adler <lists@eitanadler.com>

Merge branches 'hammer2' and 'master' of ssh://crater.dragonflybsd.org/repository/git/dragonfly into hammer2

kernel/procfs: Remove some unneeded parentheses.

Merge branches 'hammer2' and 'master' of ssh://crater.dragonflybsd.org/repository/git/dragonfly into hammer2

Kernel - Fix numerous procfs/ptrace issues

* Fix interactions during exec and exit. This should fix truss
(bug 2313).

* Reset p_* fields related to tracing on last procfs close for the
process.

kernel: Replace all usage of MALLOC()/FREE() with kmalloc()/kfree().

Initial import of binutils 2.22 on the new vendor branch

Future versions of binutils will also reside on this branch rather
than continuing to create new binutils branches for each new version.

Merge branch 'master' of /repository/git/dragonfly

kernel - Try to fix procfs readdir race

* procfs_allocvp() may have a pfs/vnode race which the vget() may not
completely address. For now make sure we can't race a vnode teardown
when attemptin

kernel - Try to fix procfs readdir race

* procfs_allocvp() may have a pfs/vnode race which the vget() may not
completely address. For now make sure we can't race a vnode teardown
when attempting to acquire a vnode with vget().

show more ...

kernel - Attempt to make procfs MPSAFE (3)

* More fixes to silly bugs. Well, I did say 'attempt' :-)

kernel - Attempt to make procfs MPSAFE (2)

* Disallow access to processes which are trying to exit.

kernel - Attempt to make procfs MPSAFE

* pfs_pfind() now acquires the p->p_token in addition to its PHOLD().

* Replace PRELE()'s with pfs_pdone() which releases the token along
with PRELE()

* Do

kernel - Attempt to make procfs MPSAFE

* pfs_pfind() now acquires the p->p_token in addition to its PHOLD().

* Replace PRELE()'s with pfs_pdone() which releases the token along
with PRELE()

* Double-check the validity of nch's passed to cache_fullpath(). This
probably still needs work.

Reported-by: swildner

show more ...

Fix a bug in linprocfs and hold lwps to prevent a race condition.

Linprocfs rolls its own prototype for procfs_domem. The function was
changed to take a struct lwp *, but neither the private protot

Fix a bug in linprocfs and hold lwps to prevent a race condition.

Linprocfs rolls its own prototype for procfs_domem. The function was
changed to take a struct lwp *, but neither the private prototype, nor
the procfs_domem call were changed accordingly. As a result any access
to the linprocfs process memory file resulted in a panic.

Procfs and linprocs perform potentially blocking calls, so HOLD and
RELE the lwps so that they can't be destroyed while procfs is blocked.

show more ...

Use SYSREF to reference count struct vnode. v_usecount is now
v_sysref(.refcnt). v_holdcnt is now v_auxrefs. SYSREF's termination state
(using a negative reference count from -0x40000000+) now pla

Use SYSREF to reference count struct vnode. v_usecount is now
v_sysref(.refcnt). v_holdcnt is now v_auxrefs. SYSREF's termination state
(using a negative reference count from -0x40000000+) now places the vnode in
a VCACHED or VFREE state and deactivates it. The vnode is now assigned a
64 bit unique id via SYSREF.

vhold() (which manipulates v_auxrefs) no longer reactivates a vnode and
is explicitly used only to track references from auxillary structures
and references to prevent premature destruction of the vnode. vdrop()
will now only move a vnode from VCACHED to VFREE on the 1->0 transition
of v_auxrefs if the vnode is in a termination state.

vref() will now panic if used on a vnode in a termination state. vget()
must now be used to explicitly reactivate a vnode. These requirements
existed before but are now explicitly asserted.

vlrureclaim() and allocvnode() should now interact a bit better. In
particular, vlrureclaim() will do a better job of finding vnodes to flush
and transition from VCACHED to VFREE, and allocvnode() will do a better
job finding vnodes to reuse without getting blocked by a flush.

allocvnode now uses a real VX lock to sequence vnodes into VRECLAIMED. All
vnode special state processing now uses a VX lock.

Vnodes are now able to be slowly returned to the memory pool when
kern.maxvnodes is reduced at run time.

Various initialization elements have been moved to CTOR/DTOR and are
no longer in the critical path, improving performance. However, since
SYSREF uses atomic_cmpset_int() (aka cmpxchgl), which reduces performance
somewhat, overall performance tends to be about the same.

show more ...