From f09738638d3bae6501e8e160c66233832d8c280f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 5 Sep 2005 08:22:52 +1000 Subject: [PATCH] [XFS] Delay direct I/O completion to a workqueue This is nessecary because aio+dio completions may happen from irq context but we need process context for converting unwritten extents. We also queue regular direct I/O completions to workqueue for regularity, there's only one queue_work call per syscall. SGI-PV: 934766 SGI-Modid: xfs-linux:xfs-kern:196857a Signed-off-by: Christoph Hellwig Signed-off-by: Nathan Scott --- fs/xfs/linux-2.6/xfs_aops.c | 74 +++++++++++++++++++++++++++++---------------- fs/xfs/linux-2.6/xfs_lrw.c | 3 -- 2 files changed, 48 insertions(+), 29 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index ed98c7a..2add9a8 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -126,7 +126,7 @@ xfs_destroy_ioend( /* * Issue transactions to convert a buffer range from unwritten - * to written extents (buffered IO). + * to written extents. */ STATIC void xfs_end_bio_unwritten( @@ -191,29 +191,6 @@ linvfs_unwritten_done( end_buffer_async_write(bh, uptodate); } -/* - * Issue transactions to convert a buffer range from unwritten - * to written extents (direct IO). - */ -STATIC void -linvfs_unwritten_convert_direct( - struct kiocb *iocb, - loff_t offset, - ssize_t size, - void *private) -{ - struct inode *inode = iocb->ki_filp->f_dentry->d_inode; - ASSERT(!private || inode == (struct inode *)private); - - /* private indicates an unwritten extent lay beneath this IO */ - if (private && size > 0) { - vnode_t *vp = LINVFS_GET_VP(inode); - int error; - - VOP_BMAP(vp, offset, size, BMAPI_UNWRITTEN, NULL, NULL, error); - } -} - STATIC int xfs_map_blocks( struct inode *inode, @@ -1045,6 +1022,44 @@ linvfs_get_blocks_direct( create, 1, BMAPI_WRITE|BMAPI_DIRECT); } +STATIC void +linvfs_end_io_direct( + struct kiocb *iocb, + loff_t offset, + ssize_t size, + void *private) +{ + xfs_ioend_t *ioend = iocb->private; + + /* + * Non-NULL private data means we need to issue a transaction to + * convert a range from unwritten to written extents. This needs + * to happen from process contect but aio+dio I/O completion + * happens from irq context so we need to defer it to a workqueue. + * This is not nessecary for synchronous direct I/O, but we do + * it anyway to keep the code uniform and simpler. + * + * The core direct I/O code might be changed to always call the + * completion handler in the future, in which case all this can + * go away. + */ + if (private && size > 0) { + ioend->io_offset = offset; + ioend->io_size = size; + xfs_finish_ioend(ioend); + } else { + ASSERT(size >= 0); + xfs_destroy_ioend(ioend); + } + + /* + * blockdev_direct_IO can return an error even afer the I/O + * completion handler was called. Thus we need to protect + * against double-freeing. + */ + iocb->private = NULL; +} + STATIC ssize_t linvfs_direct_IO( int rw, @@ -1059,16 +1074,23 @@ linvfs_direct_IO( xfs_iomap_t iomap; int maps = 1; int error; + ssize_t ret; VOP_BMAP(vp, offset, 0, BMAPI_DEVICE, &iomap, &maps, error); if (error) return -error; - return blockdev_direct_IO_own_locking(rw, iocb, inode, + iocb->private = xfs_alloc_ioend(inode); + + ret = blockdev_direct_IO_own_locking(rw, iocb, inode, iomap.iomap_target->pbr_bdev, iov, offset, nr_segs, linvfs_get_blocks_direct, - linvfs_unwritten_convert_direct); + linvfs_end_io_direct); + + if (unlikely(ret <= 0 && iocb->private)) + xfs_destroy_ioend(iocb->private); + return ret; } diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c index acab58c..3b5fabe 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.c +++ b/fs/xfs/linux-2.6/xfs_lrw.c @@ -660,9 +660,6 @@ xfs_write( (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ? mp->m_rtdev_targp : mp->m_ddev_targp; - if (ioflags & IO_ISAIO) - return XFS_ERROR(-ENOSYS); - if ((pos & target->pbr_smask) || (count & target->pbr_smask)) return XFS_ERROR(-EINVAL); -- 1.8.2.3