From 4455ca6223cc59cbc0a75f4be8bce9e84cc0d6b8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 4 Mar 2011 14:28:10 -0500 Subject: [PATCH] clear RCU on all failure exits from link_path_walk() Signed-off-by: Al Viro --- fs/namei.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index d29f91e8ff3d..f09887a45831 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1405,8 +1405,9 @@ static int link_path_walk(const char *name, struct nameidata *nd) * parent relationships. */ if (unlikely(type != LAST_NORM)) { - if (handle_dots(nd, type)) - return -ECHILD; + err = handle_dots(nd, type); + if (err) + goto return_err; continue; } @@ -1441,8 +1442,9 @@ static int link_path_walk(const char *name, struct nameidata *nd) if (lookup_flags & LOOKUP_PARENT) goto lookup_parent; if (unlikely(type != LAST_NORM)) { - if (handle_dots(nd, type)) - return -ECHILD; + err = handle_dots(nd, type); + if (err) + goto return_err; return 0; } err = do_lookup(nd, &this, &next, &inode); @@ -1475,6 +1477,12 @@ static int link_path_walk(const char *name, struct nameidata *nd) if (!(nd->flags & LOOKUP_RCU)) path_put(&nd->path); return_err: + if (nd->flags & LOOKUP_RCU) { + nd->flags &= ~LOOKUP_RCU; + nd->root.mnt = NULL; + rcu_read_unlock(); + br_read_unlock(vfsmount_lock); + } return err; } @@ -1585,16 +1593,10 @@ static int path_lookupat(int dfd, const char *name, retval = link_path_walk(name, nd); if (nd->flags & LOOKUP_RCU) { - /* RCU dangling. Cancel it. */ - if (!retval) { - if (nameidata_drop_rcu_last(nd)) - retval = -ECHILD; - } else { - nd->flags &= ~LOOKUP_RCU; - nd->root.mnt = NULL; - rcu_read_unlock(); - br_read_unlock(vfsmount_lock); - } + /* went all way through without dropping RCU */ + BUG_ON(retval); + if (nameidata_drop_rcu_last(nd)) + retval = -ECHILD; } if (!retval)