From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 1/3] xfs: add RWF_NONBLOCK support Date: Wed, 1 Oct 2014 23:04:52 +0200 Message-ID: <1412197494-7655-2-git-send-email-hch@lst.de> References: <1412197494-7655-1-git-send-email-hch@lst.de> Cc: linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com To: Milosz Tanski Return-path: Received: from casper.infradead.org ([85.118.1.10]:53050 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbaJAVCa (ORCPT ); Wed, 1 Oct 2014 17:02:30 -0400 In-Reply-To: <1412197494-7655-1-git-send-email-hch@lst.de> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Add support for non-blocking reads. The guts are handled by the generic code, the only addition is a non-blocking variant of xfs_rw_ilock. Signed-off-by: Christoph Hellwig --- fs/xfs/xfs_file.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index cf61271..f9efffc 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -61,6 +61,23 @@ xfs_rw_ilock( xfs_ilock(ip, type); } +static inline bool +xfs_rw_ilock_nowait( + struct xfs_inode *ip, + int type) +{ + if (type & XFS_IOLOCK_EXCL) { + if (!mutex_trylock(&VFS_I(ip)->i_mutex)) + return false; + } + if (!xfs_ilock_nowait(ip, type)) { + mutex_unlock(&VFS_I(ip)->i_mutex); + return false; + } + + return true; +} + static inline void xfs_rw_iunlock( struct xfs_inode *ip, @@ -246,10 +263,6 @@ xfs_file_read_iter( XFS_STATS_INC(xs_read_calls); - /* XXX: need a non-blocking iolock helper, shouldn't be too hard */ - if (iocb->ki_rwflags & RWF_NONBLOCK) - return -EAGAIN; - if (unlikely(file->f_flags & O_DIRECT)) ioflags |= XFS_IO_ISDIRECT; if (file->f_mode & FMODE_NOCMTIME) @@ -287,7 +300,14 @@ xfs_file_read_iter( * This allows the normal direct IO case of no page cache pages to * proceeed concurrently without serialisation. */ - xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + if (iocb->ki_rwflags & RWF_NONBLOCK) { + if (ioflags & XFS_IO_ISDIRECT) + return -EAGAIN; + if (!xfs_rw_ilock_nowait(ip, XFS_IOLOCK_SHARED)) + return -EAGAIN; + } else { + xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + } if ((ioflags & XFS_IO_ISDIRECT) && inode->i_mapping->nrpages) { xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); xfs_rw_ilock(ip, XFS_IOLOCK_EXCL); -- 1.9.1