Use FEATURE() macro to advertise aio availability.

When asked to use kqueue, AIO stores its internal state in the
`kn_sdata' member of the newly registered knote. The problem is that
this member is overwritten by a call to kevent(2) with the EV_ADD f

When asked to use kqueue, AIO stores its internal state in the
`kn_sdata' member of the newly registered knote. The problem is that
this member is overwritten by a call to kevent(2) with the EV_ADD flag,
targetted at the same kevent/knote. For instance, a userland application
may set the pointer to NULL, leading to a panic.

A testcase was provided by the submitter.

PR: kern/118911
Submitted by: MOROHOSHI Akihiko <moro@remus.dti.ne.jp>
MFC after: 1 day

show more ...

VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread

VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>

show more ...

vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and

vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>

show more ...

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it t

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

show more ...

Destroy the kaio_mtx on the freeing the struct kaioinfo in the
aio_proc_rundown.

Do not allow for zero-length read to be passed to the fo_read file method
by aio.

Reported and tested by: Peter Holm

Destroy the kaio_mtx on the freeing the struct kaioinfo in the
aio_proc_rundown.

Do not allow for zero-length read to be passed to the fo_read file method
by aio.

Reported and tested by: Peter Holm
Approved by: re (kensmith)

show more ...

Remove unused variable.

- Move rusage from being per-process in struct pstats to per-thread in
td_ru. This removes the requirement for per-process synchronization in
statclock() and mi_switch(). This was previously

- Move rusage from being per-process in struct pstats to per-thread in
td_ru. This removes the requirement for per-process synchronization in
statclock() and mi_switch(). This was previously supported by
sched_lock which is going away. All modifications to rusage are now
done in the context of the owning thread. reads proceed without locks.
- Aggregate exiting threads rusage in thread_exit() such that the exiting
thread's rusage is not lost.
- Provide a new routine, rufetch() to fetch an aggregate of all rusage
structures from all threads in a process. This routine must be used
in any place requiring a rusage from a process prior to it's exit. The
exited process's rusage is still available via p_ru.
- Aggregate tick statistics only on demand via rufetch() or when a thread
exits. Tick statistics are kept in the thread and protected by sched_lock
until it exits.

Initial patch by: attilio
Reviewed by: attilio, bde (some objections), arch (mostly silent)

show more ...

Further system call comment cleanup:

- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove n

Further system call comment cleanup:

- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove no-op comments consisting solely of the function name, the word
"syscall", or the system call name.
- Add punctuation.
- Re-wrap some comments.

show more ...

Merge posix4/* into normal kernel hierarchy.

Reviewed by: glanced at by jhb
Approved by: silence on -arch@ and -standards@

MFP4 (with some minor changes):

Implement the linux_io_* syscalls (AIO). They are only enabled if the native
AIO code is available (either compiled in to the kernel or as a module) at
the time the f

MFP4 (with some minor changes):

Implement the linux_io_* syscalls (AIO). They are only enabled if the native
AIO code is available (either compiled in to the kernel or as a module) at
the time the functions are used. If the AIO stuff is not available there
will be a ENOSYS.

From the submitter:
---snip---
DESIGN NOTES:

1. Linux permits a process to own multiple AIO queues (distinguished by
"context"), but FreeBSD creates only one single AIO queue per process.
My code maintains a request queue (STAILQ of queue(3)) per "context",
and throws all AIO requests of all contexts owned by a process into
the single FreeBSD per-process AIO queue.

When the process calls io_destroy(2), io_getevents(2), io_submit(2) and
io_cancel(2), my code can pick out requests owned by the specified context
from the single FreeBSD per-process AIO queue according to the per-context
request queues maintained by my code.

2. The request queue maintained by my code stores contrast information between
Linux IO control blocks (struct linux_iocb) and FreeBSD IO control blocks
(struct aiocb). FreeBSD IO control block actually exists in userland memory
space, required by FreeBSD native aio_XXXXXX(2).

3. It is quite troubling that the function io_getevents() of libaio-0.3.105
needs to use Linux-specific "struct aio_ring", which is a partial mirror
of context in user space. I would rather take the address of context in
kernel as the context ID, but the io_getevents() of libaio forces me to
take the address of the "ring" in user space as the context ID.

To my surprise, one comment line in the file "io_getevents.c" of
libaio-0.3.105 reads:

Ben will hate me for this

REFERENCE:

1. Linux kernel source code: http://www.kernel.org/pub/linux/kernel/v2.6/
(include/linux/aio_abi.h, fs/aio.c)

2. Linux manual pages: http://www.kernel.org/pub/linux/docs/manpages/
(io_setup(2), io_destroy(2), io_getevents(2), io_submit(2), io_cancel(2))

3. Linux Scalability Effort: http://lse.sourceforge.net/io/aio.html
The design notes: http://lse.sourceforge.net/io/aionotes.txt

4. The package libaio, both source and binary:
http://rpmfind.net/linux/rpm2html/search.php?query=libaio
Simple transparent interface to Linux AIO system calls.

5. Libaio-oracle: http://oss.oracle.com/projects/libaio-oracle/
POSIX AIO implementation based on Linux AIO system calls (depending on
libaio).
---snip---

Submitted by: Li, Xiao <intron@intron.ac>

show more ...

hide kqueue_register from public view, and replace it w/ kqfd_register...
this eliminates a possible race in aio registering a kevent..

Remove call to fdfree() for the AIO daemons to prevent kernel panics
with linprocfs. This call is not needed since file descriptor sharing
was removed in v1.125.

Reviewed by: alc, davidxu, ambrisko

Remove call to fdfree() for the AIO daemons to prevent kernel panics
with linprocfs. This call is not needed since file descriptor sharing
was removed in v1.125.

Reviewed by: alc, davidxu, ambrisko
MFC after: 3 days

show more ...

- Change process_exec function handlers prototype to include struct
image_params arg.
- Change struct image_params to include struct sysentvec pointer and
initialize it.
- Change all consumers of

- Change process_exec function handlers prototype to include struct
image_params arg.
- Change struct image_params to include struct sysentvec pointer and
initialize it.
- Change all consumers of process_exit/process_exec eventhandlers to
new prototypes (includes splitting up into distinct exec/exit functions).
- Add eventhandler to userret.

Sponsored by: Google SoC 2006
Submitted by: rdivacky
Parts suggested by: jhb (on hackers@)

show more ...

Make lio ident more consistant with aio ident.

Use a dedicated mutex to protect aio queues, the movation is to reduce
lock contention with other parts.

1. Move code for scanning pending I/O from aio_fsync to aio_aqueue,
it has less overhead.
2. Avoid scheduling task if maximum number of I/O threads is reached.

Implement aio_fsync() syscall.

1. Remove aio entry from lists earlier in aio_free_entry,
so other threads can not see it if we unlock the proc
lock (this can happen in knlist_delete). Don't do wakeup,
it is not necessary

1. Remove aio entry from lists earlier in aio_free_entry,
so other threads can not see it if we unlock the proc
lock (this can happen in knlist_delete). Don't do wakeup,
it is not necessary.

2. Decrease kaio_buffer_count in biohelper rather than
doing it in aio_bio_done_notify.

3. In aio_bio_done_notify, don't send notification if KAIO_RUNDOWN
was set, because the process is already in single thread mode.

4. Use assignment to initialize aiothreadflags.

5. AIOCBLIST_RUNDOWN is not useful, axe the code using it.

6. use LIO_NOP instead of zero.

show more ...

If block size is zero, use normal file operations to do I/O,
this eliminates a divided-by-zero fault.

Recommended by: phk

Just like dofilewrite(), call bwillwrite before fo_write.

return final error code in aio_return rather than a hardcoded 0.

in aio_aqueue, store same return code into job->_aiocb_private.error.
in aio_return, unlock proc lock before suword.

Add locking annotation and comments about socket, pipe, fifo problem.
Temporarily fix a locking problem for socket I/O.

Er, rescure a deleted comment line.