linux.git/include/uapi/linux/aio_abi.h, branch v6.12.80

aio: Comment use of IOCB_FLAG_IOPRIO aio flag

2018-11-20T02:03:43+00:00

Comment the use of the IOCB_FLAG_IOPRIO aio flag similarly to the
IOCB_FLAG_RESFD flag.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Damien Le Moal 
Signed-off-by: Jens Axboe

aio: implement IOCB_CMD_POLL

2018-08-06T08:24:33+00:00

Simple one-shot poll through the io_submit() interface.  To poll for
a file descriptor the application should submit an iocb of type
IOCB_CMD_POLL.  It will poll the fd for the events specified in the
the first 32 bits of the aio_buf field of the iocb.

Unlike poll or epoll without EPOLLONESHOT this interface always works
in one shot mode, that is once the iocb is completed, it will have to be
resubmitted.

Signed-off-by: Christoph Hellwig 
Tested-by: Avi Kivity

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-07-22T19:04:51+00:00

Pull vfs fixes from Al Viro:
 "Fix several places that screw up cleanups after failures halfway
  through opening a file (one open-coding filp_clone_open() and getting
  it wrong, two misusing alloc_file()). That part is -stable fodder from
  the 'work.open' branch.

  And Christoph's regression fix for uapi breakage in aio series;
  include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel
  definition of sigset_t, the reason for doing so in the first place had
  been bogus - there's no need to expose struct __aio_sigset in
  aio_abi.h at all"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: don't expose __aio_sigset in uapi
  ocxlflash_getfile(): fix double-iput() on alloc_file() failures
  cxl_getfile(): fix double-iput() on alloc_file() failures
  drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()

aio: don't expose __aio_sigset in uapi

2018-07-18T03:26:58+00:00

glibc uses a different defintion of sigset_t than the kernel does,
and the current version would pull in both.  To fix this just do not
expose the type at all - this somewhat mirrors pselect() where we
do not even have a type for the magic sigmask argument, but just
use pointer arithmetics.

Fixes: 7a074e96 ("aio: implement io_pgetevents")
Signed-off-by: Christoph Hellwig 
Reported-by: Adrian Reber 
Signed-off-by: Al Viro

aio: mark __aio_sigset::sigmask const

2018-06-29T13:51:57+00:00

io_pgetevents() will not change the signal mask.  Mark it const to make
it clear and to reduce the need for casts in user code.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Avi Kivity 
Signed-off-by: Al Viro 
[hch: reapply the patch that got incorrectly reverted]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Linus Torvalds

Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL

2018-06-28T17:40:47+00:00

The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Linus Torvalds

aio: mark __aio_sigset::sigmask const

2018-06-15T00:06:19+00:00

io_pgetevents() will not change the signal mask. Mark it const
to make it clear and to reduce the need for casts in user code.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Avi Kivity 
Signed-off-by: Al Viro

fs: Add aio iopriority support

2018-05-31T14:50:55+00:00

This is the per-I/O equivalent of the ioprio_set system call.

When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the
newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field.

This patch depends on block: add ioprio_check_cap function.

Signed-off-by: Adam Manzanares 
Reviewed-by: Jeff Moyer 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Al Viro

aio: implement IOCB_CMD_POLL

2018-05-26T07:16:44+00:00

Simple one-shot poll through the io_submit() interface.  To poll for
a file descriptor the application should submit an iocb of type
IOCB_CMD_POLL.  It will poll the fd for the events specified in the
the first 32 bits of the aio_buf field of the iocb.

Unlike poll or epoll without EPOLLONESHOT this interface always works
in one shot mode, that is once the iocb is completed, it will have to be
resubmitted.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong

aio: implement io_pgetevents

2018-05-02T17:57:24+00:00

This is the io_getevents equivalent of ppoll/pselect and allows to
properly mix signals and aio completions (especially with IOCB_CMD_POLL)
and atomically executes the following sequence:

	sigset_t origmask;

	pthread_sigmask(SIG_SETMASK, &sigmask, &origmask);
	ret = io_getevents(ctx, min_nr, nr, events, timeout);
	pthread_sigmask(SIG_SETMASK, &origmask, NULL);

Note that unlike many other signal related calls we do not pass a sigmask
size, as that would get us to 7 arguments, which aren't easily supported
by the syscall infrastructure.  It seems a lot less painful to just add a
new syscall variant in the unlikely case we're going to increase the
sigset size.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Darrick J. Wong