linux.git/fs/aio.c, branch v2.6.34

aio: remove unused field

2009-12-16T15:20:13+00:00

Don't know the reason, but it appears ki_wait field of iocb never gets used.

Signed-off-by: Shaohua Li 
Cc: Jeff Moyer 
Cc: Benjamin LaHaise 
Cc: Zach Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: move bdi/address_space unplug functions to backing-dev.h

2009-10-29T12:59:26+00:00

There's nothing block related about them, the backing device
is used by things like NFS etc as well. This gets rid of the
need to protect such calls by CONFIG_BLOCK.

Signed-off-by: Jens Axboe

aio: implement request batching

2009-10-28T08:29:25+00:00

Hi,

Some workloads issue batches of small I/O, and the performance is poor
due to the call to blk_run_address_space for every single iocb.  Nathan
Roberts pointed this out, and suggested that by deferring this call
until all I/Os in the iocb array are submitted to the block layer, we
can realize some impressive performance gains (up to 30% for sequential
4k reads in batches of 16).

Signed-off-by: Jeff Moyer 
Signed-off-by: Jens Axboe

aio.c: move EXPORT* macros to line after function

2009-09-23T14:39:29+00:00

As mentioned in Documentation/CodingStyle, move EXPORT* macro's
to the line immediately after the closing function brace line.

Also, move the __initcall() similarly.

Signed-off-by: H Hartley Sweeten 
Cc: Zach Brown 
Cc: Benjamin LaHaise 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move use_mm/unuse_mm from aio.c to mm/

2009-09-22T14:17:42+00:00

Anyone who wants to do copy to/from user from a kernel thread, needs
use_mm (like what fs/aio has).  Move that into mm/, to make reusing and
exporting easier down the line, and make aio use it.  Next intended user,
besides aio, will be vhost-net.

Acked-by: Andrea Arcangeli 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

eventfd: revised interface and cleanups

2009-07-01T01:55:58+00:00

Change the eventfd interface to de-couple the eventfd memory context, from
the file pointer instance.

Without such change, there is no clean way to racely free handle the
POLLHUP event sent when the last instance of the file* goes away.  Also,
now the internal eventfd APIs are using the eventfd context instead of the
file*.

This patch is required by KVM's IRQfd code, which is still under
development.

Signed-off-by: Davide Libenzi 
Cc: Gregory Haskins 
Cc: Rusty Russell 
Cc: Benjamin LaHaise 
Cc: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

aio: lookup_ioctx can return the wrong value when looking up a bogus context

2009-03-19T22:57:18+00:00

The libaio test harness turned up a problem whereby lookup_ioctx on a
bogus io context was returning the 1 valid io context from the list
(harness/cases/3.p).

Because of that, an extra put_iocontext was done, and when the process
exited, it hit a BUG_ON in the put_iocontext macro called from exit_aio
(since we expect a users count of 1 and instead get 0).

The problem was introduced by "aio: make the lookup_ioctx() lockless"
(commit abf137dd7712132ee56d5b3143c2ff61a72a5faa).

Thanks to Zach for pointing out that hlist_for_each_entry_rcu will not
return with a NULL tpos at the end of the loop, even if the entry was
not found.

Signed-off-by: Jeff Moyer 
Acked-by: Zach Brown 
Acked-by: Jens Axboe 
Cc: Benjamin LaHaise 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

eventfd: remove fput() call from possible IRQ context

2009-03-19T22:57:18+00:00

Remove a source of fput() call from inside IRQ context.  Myself, like Eric,
wasn't able to reproduce an fput() call from IRQ context, but Jeff said he was
able to, with the attached test program.  Independently from this, the bug is
conceptually there, so we might be better off fixing it.  This patch adds an
optimization similar to the one we already do on ->ki_filp, on ->ki_eventfd.
Playing with ->f_count directly is not pretty in general, but the alternative
here would be to add a brand new delayed fput() infrastructure, that I'm not
sure is worth it.

Signed-off-by: Davide Libenzi 
Cc: Benjamin LaHaise 
Cc: Trond Myklebust 
Cc: Eric Dumazet 
Signed-off-by: Jeff Moyer 
Cc: Zach Brown 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[CVE-2009-0029] System call wrappers part 16

2009-01-14T13:15:25+00:00

Signed-off-by: Heiko Carstens

aio: make the lookup_ioctx() lockless

2008-12-29T07:29:50+00:00

The mm->ioctx_list is currently protected by a reader-writer lock,
so we always grab that lock on the read side for doing ioctx
lookups. As the workload is extremely reader biased, turn this into
an rcu hlist so we can make lookup_ioctx() lockless. Get rid of
the rwlock and use a spinlock for providing update side exclusion.

There's usually only 1 entry on this list, so it doesn't make sense
to look into fancier data structures.

Reviewed-by: Jeff Moyer 
Signed-off-by: Jens Axboe