linux-toradex.git/include/linux/aio.h, branch v3.14.3

aio: Kill ki_dtor

2013-07-30T15:53:12+00:00

sock_aio_dtor() is dead code - and stuff that does need to do cleanup
can simply do it before calling aio_complete().

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Cc: Theodore Ts'o 
Signed-off-by: Benjamin LaHaise

aio: Kill ki_users

2013-07-30T15:53:12+00:00

The kiocb refcount is only needed for cancellation - to ensure a kiocb
isn't freed while a ki_cancel callback is running. But if we restrict
ki_cancel callbacks to not block (which they currently don't), we can
simply drop the refcount.

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Cc: Theodore Ts'o 
Signed-off-by: Benjamin LaHaise

aio: Kill unneeded kiocb members

2013-07-30T15:53:12+00:00

The old aio retry infrastucture needed to save the various arguments to
to aio operations. But with the retry infrastructure gone, we can trim
struct kiocb quite a bit.

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Cc: Theodore Ts'o 
Signed-off-by: Benjamin LaHaise

aio: Kill aio_rw_vect_retry()

2013-07-30T15:53:12+00:00

This code doesn't serve any purpose anymore, since the aio retry
infrastructure has been removed.

This change should be safe because aio_read/write are also used for
synchronous IO, and called from do_sync_read()/do_sync_write() - and
there's no looping done in the sync case (the read and write syscalls).

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Signed-off-by: Benjamin LaHaise

aio: io_cancel() no longer returns the io_event

2013-07-30T15:53:11+00:00

Originally, io_event() was documented to return the io_event if
cancellation succeeded - the io_event wouldn't be delivered via the ring
buffer like it normally would.

But this isn't what the implementation was actually doing; the only
driver implementing cancellation, the usb gadget code, never returned an
io_event in its cancel function. And aio_complete() was recently changed
to no longer suppress event delivery if the kiocb had been cancelled.

This gets rid of the unused io_event argument to kiocb_cancel() and
kiocb->ki_cancel(), and changes io_cancel() to return -EINPROGRESS if
kiocb->ki_cancel() returned success.

Also tweak the refcounting in kiocb_cancel() to make more sense.

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Signed-off-by: Benjamin LaHaise

aio: kill ki_retry

2013-05-08T02:46:02+00:00

Thanks to Zach Brown's work to rip out the retry infrastructure, we don't
need this anymore - ki_retry was only called right after the kiocb was
initialized.

This also refactors and trims some duplicated code, as well as cleaning up
the refcounting/error handling a bit.

[akpm@linux-foundation.org: use fmode_t in aio_run_iocb()]
[akpm@linux-foundation.org: fix file_start_write/file_end_write tests]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Reviewed-by: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aio: kill ki_key

2013-05-08T02:41:50+00:00

ki_key wasn't actually used for anything previously - it was always 0.
Drop it to trim struct kiocb a bit.

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Reviewed-by: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aio: kill batch allocation

2013-05-08T01:38:29+00:00

Previously, allocating a kiocb required touching quite a few global
(well, per kioctx) cachelines...  so batching up allocation to amortize
those was worthwhile.  But we've gotten rid of some of those, and in
another couple of patches kiocb allocation won't require writing to any
shared cachelines, so that means we can just rip this code out.

Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Reviewed-by: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aio: use cancellation list lazily

2013-05-08T01:38:29+00:00

Cancelling kiocbs requires adding them to a per kioctx linked list,
which is one of the few things we need to take the kioctx lock for in
the fast path.  But most kiocbs can't be cancelled - so if we just do
this lazily, we can avoid quite a bit of locking overhead.

While we're at it, instead of using a flag bit switch to using ki_cancel
itself to indicate that a kiocb has been cancelled/completed.  This lets
us get rid of ki_flags entirely.

[akpm@linux-foundation.org: remove buggy BUG()]
Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Reviewed-by: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aio: make aio_put_req() lockless

2013-05-08T01:38:28+00:00

Freeing a kiocb needed to touch the kioctx for three things:

 * Pull it off the reqs_active list
 * Decrementing reqs_active
 * Issuing a wakeup, if the kioctx was in the process of being freed.

This patch moves these to aio_complete(), for a couple reasons:

 * aio_complete() already has to issue the wakeup, so if we drop the
   kioctx refcount before aio_complete does its wakeup we don't have to
   do it twice.
 * aio_complete currently has to take the kioctx lock, so it makes sense
   for it to pull the kiocb off the reqs_active list too.
 * A later patch is going to change reqs_active to include unreaped
   completions - this will mean allocating a kiocb doesn't have to look
   at the ringbuffer. So taking the decrement of reqs_active out of
   kiocb_free() is useful prep work for that patch.

This doesn't really affect cancellation, since existing (usb) code that
implements a cancel function still calls aio_complete() - we just have
to make sure that aio_complete does the necessary teardown for cancelled
kiocbs.

It does affect code paths where we free kiocbs that were never
submitted; they need to decrement reqs_active and pull the kiocb off the
reqs_active list.  This occurs in two places: kiocb_batch_free(), which
is going away in a later patch, and the error path in io_submit_one.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Kent Overstreet 
Cc: Zach Brown 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Rusty Russell 
Cc: Jens Axboe 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Acked-by: Jeff Moyer 
Cc: Al Viro 
Cc: Benjamin LaHaise 
Reviewed-by: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds