From: Bob Peterson Date: Thu, 16 Mar 2017 19:29:13 +0000 (-0400) Subject: GFS2: Temporarily zero i_no_addr when creating a dinode X-Git-Tag: v4.12-rc1~88^2~6 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=cc963a11b67b796c25c5b827b25d2bcc92ce1779;p=karo-tx-linux.git GFS2: Temporarily zero i_no_addr when creating a dinode Before this patch i_no_addr was not initialized until after the return from allocating its block. That meant the i_no_addr was temporarily uninitialized storage. Ordinarily that's not a concern, but if inplace_reserve can't find space, it can call try_rgrp_unlink which references i_no_addr as a block to avoid. That can result in unpredictable behavior. More importantly, the trace point in gfs2_alloc_blocks references ip->i_no_addr before it is set, which is misleading when reading the kernel traces. This patch makes it look like the new dinode block was assigned in the name of inode 0 rather than a random inode that's completely unrelated. Signed-off-by: Bob Peterson --- diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index e279c3ce27be..4f405d43a86b 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -667,6 +667,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry, ip->i_height = 0; ip->i_depth = 0; ip->i_entries = 0; + ip->i_no_addr = 0; /* Temporarily zero until real addr is assigned */ switch(mode & S_IFMT) { case S_IFREG: