From 721259bce2851893155c6cb88a3f8ecb106b348c Mon Sep 17 00:00:00 2001 From: Lachlan McIlroy Date: Thu, 7 Sep 2006 14:27:05 +1000 Subject: [PATCH] [XFS] Fix ABBA deadlock between i_mutex and iolock. Avoid calling __blockdev_direct_IO for the DIO_OWN_LOCKING case for direct I/O reads since it drops and reacquires the i_mutex while holding the iolock and this violates the locking order. SGI-PV: 955696 SGI-Modid: xfs-linux-melb:xfs-kern:26898a Signed-off-by: Lachlan McIlroy Signed-off-by: David Chatterton --- fs/xfs/linux-2.6/xfs_aops.c | 18 +++++++++++++----- fs/xfs/linux-2.6/xfs_lrw.c | 11 ++++++----- 2 files changed, 19 insertions(+), 10 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index c40f81b..34dcb43 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1390,11 +1390,19 @@ xfs_vm_direct_IO( iocb->private = xfs_alloc_ioend(inode, IOMAP_UNWRITTEN); - ret = blockdev_direct_IO_own_locking(rw, iocb, inode, - iomap.iomap_target->bt_bdev, - iov, offset, nr_segs, - xfs_get_blocks_direct, - xfs_end_io_direct); + if (rw == WRITE) { + ret = blockdev_direct_IO_own_locking(rw, iocb, inode, + iomap.iomap_target->bt_bdev, + iov, offset, nr_segs, + xfs_get_blocks_direct, + xfs_end_io_direct); + } else { + ret = blockdev_direct_IO_no_locking(rw, iocb, inode, + iomap.iomap_target->bt_bdev, + iov, offset, nr_segs, + xfs_get_blocks_direct, + xfs_end_io_direct); + } if (unlikely(ret <= 0 && iocb->private)) xfs_destroy_ioend(iocb->private); diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c index 5d9cfd9..110c038 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.c +++ b/fs/xfs/linux-2.6/xfs_lrw.c @@ -264,7 +264,9 @@ xfs_read( dmflags, &locktype); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); - goto unlock_mutex; + if (unlikely(ioflags & IO_ISDIRECT)) + mutex_unlock(&inode->i_mutex); + return ret; } } @@ -272,6 +274,9 @@ xfs_read( bhv_vop_flushinval_pages(vp, ctooff(offtoct(*offset)), -1, FI_REMAPF_LOCKED); + if (unlikely(ioflags & IO_ISDIRECT)) + mutex_unlock(&inode->i_mutex); + xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore, (void *)iovp, segs, *offset, ioflags); ret = __generic_file_aio_read(iocb, iovp, segs, offset); @@ -281,10 +286,6 @@ xfs_read( XFS_STATS_ADD(xs_read_bytes, ret); xfs_iunlock(ip, XFS_IOLOCK_SHARED); - -unlock_mutex: - if (unlikely(ioflags & IO_ISDIRECT)) - mutex_unlock(&inode->i_mutex); return ret; } -- 2.7.4