tree 10a7b6f647945c63f17c6d55c346e84d99130ac3
parent 9830f4be159b29399d107bffb99e0132bc5aedd4
author Goldwyn Rodrigues <rgoldwyn@suse.com> 1497960343 -0500
committer Jens Axboe <axboe@kernel.dk> 1497964323 -0600

fs: Introduce RWF_NOWAIT and FMODE_AIO_NOWAIT

RWF_NOWAIT informs kernel to bail out if an AIO request will block
for reasons such as file allocations, or a writeback triggered,
or would block while allocating requests while performing
direct I/O.

RWF_NOWAIT is translated to IOCB_NOWAIT for iocb->ki_flags.

FMODE_AIO_NOWAIT is a flag which identifies the file opened is capable
of returning -EAGAIN if the AIO call will block. This must be set by
supporting filesystems in the ->open() call.

Filesystems xfs, btrfs and ext4 would be supported in the following patches.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>