From patchwork Tue Jun 22 12:21:45 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 56468 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 2ECA3B6F11 for ; Tue, 22 Jun 2010 22:31:18 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755437Ab0FVMbP (ORCPT ); Tue, 22 Jun 2010 08:31:15 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:46250 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158Ab0FVMbN (ORCPT ); Tue, 22 Jun 2010 08:31:13 -0400 Received: from hch by bombadil.infradead.org with local (Exim 4.72 #1 (Red Hat Linux)) id 1OR2dF-0004wI-3a; Tue, 22 Jun 2010 12:31:13 +0000 Message-Id: <20100622123113.011371666@bombadil.infradead.org> User-Agent: quilt/0.47-1 Date: Tue, 22 Jun 2010 08:21:45 -0400 From: Christoph Hellwig To: linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org Subject: [PATCH 1/2] direct-io: move aio_complete into ->end_io References: <20100622122144.302857146@bombadil.infradead.org> Content-Disposition: inline; filename=direct-io-unwritten-fix X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Filesystems with unwritten extent support must not complete an AIO request until the transaction to convert the extent has been commited. That means the aio_complete calls needs to be moved into the ->end_io callback so that the filesystem can control when to call it exactly. This makes a bit of a mess out of dio_complete and the ->end_io callback prototype even more complicated. In addition ->end_io is now called with i_alloc_sem held for DIO_LOCKING filesystems. The only filesystem that has both and ->end_io callback and sets DIO_LOCKING is ext4, which doesn't appear to do anything that could deadlock with i_alloc_sem in ->end_io. Signed-off-by: Christoph Hellwig --- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-2.6/fs/direct-io.c =================================================================== --- linux-2.6.orig/fs/direct-io.c 2010-06-22 09:48:37.239004298 +0200 +++ linux-2.6/fs/direct-io.c 2010-06-22 11:54:42.281003878 +0200 @@ -218,7 +218,7 @@ static struct page *dio_get_page(struct * filesystems can use it to hold additional state between get_block calls and * dio_complete. */ -static int dio_complete(struct dio *dio, loff_t offset, int ret) +static int dio_complete(struct dio *dio, loff_t offset, int ret, bool is_async) { ssize_t transferred = 0; @@ -239,14 +239,6 @@ static int dio_complete(struct dio *dio, transferred = dio->i_size - offset; } - if (dio->end_io && dio->result) - dio->end_io(dio->iocb, offset, transferred, - dio->map_bh.b_private); - - if (dio->flags & DIO_LOCKING) - /* lockdep: non-owner release */ - up_read_non_owner(&dio->inode->i_alloc_sem); - if (ret == 0) ret = dio->page_errors; if (ret == 0) @@ -254,6 +246,17 @@ static int dio_complete(struct dio *dio, if (ret == 0) ret = transferred; + if (dio->end_io && dio->result) { + dio->end_io(dio->iocb, offset, transferred, + dio->map_bh.b_private, ret, is_async); + } else if (is_async) { + aio_complete(dio->iocb, ret, 0); + } + + if (dio->flags & DIO_LOCKING) + /* lockdep: non-owner release */ + up_read_non_owner(&dio->inode->i_alloc_sem); + return ret; } @@ -277,8 +280,7 @@ static void dio_bio_end_aio(struct bio * spin_unlock_irqrestore(&dio->bio_lock, flags); if (remaining == 0) { - int ret = dio_complete(dio, dio->iocb->ki_pos, 0); - aio_complete(dio->iocb, ret, 0); + dio_complete(dio, dio->iocb->ki_pos, 0, true); kfree(dio); } } @@ -1126,7 +1128,7 @@ direct_io_worker(int rw, struct kiocb *i spin_unlock_irqrestore(&dio->bio_lock, flags); if (ret2 == 0) { - ret = dio_complete(dio, offset, ret); + ret = dio_complete(dio, offset, ret, false); kfree(dio); } else BUG_ON(ret != -EIOCBQUEUED); Index: linux-2.6/fs/ext4/inode.c =================================================================== --- linux-2.6.orig/fs/ext4/inode.c 2010-06-22 09:48:37.249004508 +0200 +++ linux-2.6/fs/ext4/inode.c 2010-06-22 12:18:45.883255381 +0200 @@ -3775,7 +3775,8 @@ static ext4_io_end_t *ext4_init_io_end ( } static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, - ssize_t size, void *private) + ssize_t size, void *private, int ret, + bool is_async) { ext4_io_end_t *io_end = iocb->private; struct workqueue_struct *wq; @@ -3784,7 +3785,7 @@ static void ext4_end_io_dio(struct kiocb /* if not async direct IO or dio with 0 bytes write, just return */ if (!io_end || !size) - return; + goto out; ext_debug("ext4_end_io_dio(): io_end 0x%p" "for inode %lu, iocb 0x%p, offset %llu, size %llu\n", @@ -3795,7 +3796,7 @@ static void ext4_end_io_dio(struct kiocb if (io_end->flag != EXT4_IO_UNWRITTEN){ ext4_free_io_end(io_end); iocb->private = NULL; - return; + goto out; } io_end->offset = offset; @@ -3812,6 +3813,9 @@ static void ext4_end_io_dio(struct kiocb list_add_tail(&io_end->list, &ei->i_completed_io_list); spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); iocb->private = NULL; +out: + if (is_async) + aio_complete(iocb, ret, 0); } static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate) Index: linux-2.6/fs/ocfs2/aops.c =================================================================== --- linux-2.6.orig/fs/ocfs2/aops.c 2010-06-22 09:48:37.259012749 +0200 +++ linux-2.6/fs/ocfs2/aops.c 2010-06-22 12:19:03.931005757 +0200 @@ -609,7 +609,9 @@ bail: static void ocfs2_dio_end_io(struct kiocb *iocb, loff_t offset, ssize_t bytes, - void *private) + void *private, + int ret, + bool is_async) { struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; int level; @@ -623,6 +625,9 @@ static void ocfs2_dio_end_io(struct kioc if (!level) up_read(&inode->i_alloc_sem); ocfs2_rw_unlock(inode, level); + + if (is_async) + aio_complete(iocb, ret, 0); } /* Index: linux-2.6/fs/xfs/linux-2.6/xfs_aops.c =================================================================== --- linux-2.6.orig/fs/xfs/linux-2.6/xfs_aops.c 2010-06-22 09:48:37.268012190 +0200 +++ linux-2.6/fs/xfs/linux-2.6/xfs_aops.c 2010-06-22 14:05:02.522005722 +0200 @@ -1599,7 +1599,9 @@ xfs_end_io_direct( struct kiocb *iocb, loff_t offset, ssize_t size, - void *private) + void *private, + int ret, + bool is_async) { xfs_ioend_t *ioend = iocb->private; @@ -1645,6 +1647,9 @@ xfs_end_io_direct( * against double-freeing. */ iocb->private = NULL; + + if (is_async) + aio_complete(iocb, ret, 0); } STATIC ssize_t Index: linux-2.6/fs/xfs/linux-2.6/xfs_aops.h =================================================================== --- linux-2.6.orig/fs/xfs/linux-2.6/xfs_aops.h 2010-06-22 09:48:37.278274238 +0200 +++ linux-2.6/fs/xfs/linux-2.6/xfs_aops.h 2010-06-22 09:49:12.388034051 +0200 @@ -37,6 +37,8 @@ typedef struct xfs_ioend { size_t io_size; /* size of the extent */ xfs_off_t io_offset; /* offset in the file */ struct work_struct io_work; /* xfsdatad work queue */ + struct kiocb *io_iocb; + int io_result; } xfs_ioend_t; extern const struct address_space_operations xfs_address_space_operations; Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2010-06-22 09:49:07.188253984 +0200 +++ linux-2.6/include/linux/fs.h 2010-06-22 10:34:10.128005975 +0200 @@ -415,7 +415,8 @@ struct buffer_head; typedef int (get_block_t)(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, - ssize_t bytes, void *private); + ssize_t bytes, void *private, int ret, + bool is_async); /* * Attribute flags. These should be or-ed together to figure out what