From c32676eea19ce29cb74dba0f97b085e83f6b8915 Mon Sep 17 00:00:00 2001 From: David Chinner Date: Thu, 19 Jul 2007 16:28:58 +1000 Subject: [XFS] Fix inode size update before data write in xfs_setattr When changing the file size by a truncate() call, we log the change in the inode size. However, we do not flush any outstanding data that might not have been written to disk, thereby violating the data/inode size update order. This can leave files full of NULLs on crash. Hence if we are truncating the file, flush any unwritten data that may lie between the curret on disk inode size and the new inode size that is being logged to ensure that ordering is preserved. SGI-PV: 966308 SGI-Modid: xfs-linux-melb:xfs-kern:29174a Signed-off-by: David Chinner Signed-off-by: Christoph Hellwig Signed-off-by: Tim Shimmin --- fs/xfs/xfs_vnodeops.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c index 401cb00a55d6..1a5ad8cd97b0 100644 --- a/fs/xfs/xfs_vnodeops.c +++ b/fs/xfs/xfs_vnodeops.c @@ -589,7 +589,30 @@ xfs_setattr( code = xfs_igrow_start(ip, vap->va_size, credp); } xfs_iunlock(ip, XFS_ILOCK_EXCL); - vn_iowait(vp); /* wait for the completion of any pending DIOs */ + + /* + * We are going to log the inode size change in this + * transaction so any previous writes that are beyond the on + * disk EOF and the new EOF that have not been written out need + * to be written here. If we do not write the data out, we + * expose ourselves to the null files problem. + * + * Only flush from the on disk size to the smaller of the in + * memory file size or the new size as that's the range we + * really care about here and prevents waiting for other data + * not within the range we care about here. + */ + if (!code && + (ip->i_size != ip->i_d.di_size) && + (vap->va_size > ip->i_d.di_size)) { + code = bhv_vop_flush_pages(XFS_ITOV(ip), + ip->i_d.di_size, vap->va_size, + XFS_B_ASYNC, FI_NONE); + } + + /* wait for all I/O to complete */ + vn_iowait(vp); + if (!code) code = xfs_itruncate_data(ip, vap->va_size); if (code) { -- cgit v1.2.3