On Tue, Jun 20, 2017 at 01:24:28AM +0100, Al Viro wrote: > On Mon, Jun 19, 2017 at 05:36:05PM -0600, Jens Axboe wrote: > > On 06/19/2017 05:34 PM, Al Viro wrote: > > > On Mon, Jun 19, 2017 at 05:15:16PM -0600, Jens Axboe wrote: > > >> On 06/19/2017 10:33 AM, Goldwyn Rodrigues wrote: > > >>> Jens, > > >>> > > >>> As Christoph suggested, I am sending the patches against the block > > >>> tree for merge since the block layer changes had the most conflicts. > > >>> My tree is at https://github.com/goldwynr/linux/tree/nowait-block > > >> > > >> I can merge it for 4.13, but I need Al to be happy with it first. > > > > > > FWIW, it's really a matter of who gets more conflicts - I'm OK with the > > > general shape of that code and it could go through either tree (or both, > > > for that matter, if an immutable branch is promised). > > > > I'm still hopeful that the write hint patchset will make it as well, > > which will definitely conflict with this. So if you don't mind, I'd > > like to queue it through the block tree. The block for-4.x/ branches > > are not rebased. > > Fine by me; the only problem I see there at the moment is with ext4 and > xfs ->read_iter() not buggering off on nowait (xfs one has > xfs_ilock(ip, XFS_IOLOCK_SHARED); > done before it gets to generic_file_read_iter()). Something like the patch below should take care of the XFS, free feel to fold. diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index e159eb381d9f..c74847f71b3d 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -216,7 +216,11 @@ xfs_file_dio_aio_read( file_accessed(iocb->ki_filp); - xfs_ilock(ip, XFS_IOLOCK_SHARED); + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + xfs_ilock(ip, XFS_IOLOCK_SHARED); + } ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL); xfs_iunlock(ip, XFS_IOLOCK_SHARED); @@ -237,7 +241,11 @@ xfs_file_dax_read( if (!count) return 0; /* skip atime */ - xfs_ilock(ip, XFS_IOLOCK_SHARED); + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + xfs_ilock(ip, XFS_IOLOCK_SHARED); + } ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops); xfs_iunlock(ip, XFS_IOLOCK_SHARED);
