From b67f04e53c2968bad8783b4321a7ec2e1f325d86 Mon Sep 17 00:00:00 2001 From: green Date: Fri, 16 Jan 2004 16:31:01 +0000 Subject: Fix an upper-vnode leak created in revision 1.52. When an upper-layer file has been removed, it should be purged from the cache, but it need not be removed from the directory stack causing corruption; instead, it will simply be removed once the last references and holds on it are dropped at the end of the unlink/rmdir system calls, and the normal !UN_CACHED VOP_INACTIVE() handler for unionfs finishes it off. This is easily reproduced by repeated "echo >file; rm file" on a unionfs mount. Strangely, "echo -n >file; rm file" didn't make it happen. --- sys/fs/unionfs/union_subr.c | 27 +++++++++++---------------- sys/fs/unionfs/union_vnops.c | 5 ++--- 2 files changed, 13 insertions(+), 19 deletions(-) (limited to 'sys') diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c index 896a5b9..fab061a 100644 --- a/sys/fs/unionfs/union_subr.c +++ b/sys/fs/unionfs/union_subr.c @@ -1155,38 +1155,33 @@ union_vn_close(vp, fmode, cred, td) return (VOP_CLOSE(vp, fmode, cred, td)); } -#if 0 - /* * union_removed_upper: * - * called with union_node unlocked. XXX + * An upper-only file/directory has been removed; un-cache it so + * that unionfs vnode gets reclaimed and the last uppervp reference + * disappears. + * + * Called with union_node unlocked. */ void union_removed_upper(un) struct union_node *un; { - struct thread *td = curthread; /* XXX */ - struct vnode **vpp; - - /* - * Do not set the uppervp to NULLVP. If lowervp is NULLVP, - * union node will have neither uppervp nor lowervp. We remove - * the union node from cache, so that it will not be referrenced. - */ - union_newupper(un, NULLVP); - if (un->un_dircache != NULL) - union_dircache_free(un); + struct thread *td = curthread; if (un->un_flags & UN_CACHED) { + int hash = UNION_HASH(un->un_uppervp, un->un_lowervp); + + while (union_list_lock(hash)) + continue; un->un_flags &= ~UN_CACHED; LIST_REMOVE(un, un_cache); + union_list_unlock(hash); } } -#endif - /* * Determine whether a whiteout is needed * during a remove/rmdir operation. diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c index be7b28c..603acd1 100644 --- a/sys/fs/unionfs/union_vnops.c +++ b/sys/fs/unionfs/union_vnops.c @@ -1225,11 +1225,8 @@ union_remove(ap) if (union_dowhiteout(un, cnp->cn_cred, td)) cnp->cn_flags |= DOWHITEOUT; error = VOP_REMOVE(upperdvp, uppervp, cnp); -#if 0 - /* XXX */ if (!error) union_removed_upper(un); -#endif union_unlock_upper(uppervp, td); } else { error = union_mkwhiteout( @@ -1542,6 +1539,8 @@ union_rmdir(ap) if (union_dowhiteout(un, cnp->cn_cred, td)) cnp->cn_flags |= DOWHITEOUT; error = VOP_RMDIR(upperdvp, uppervp, ap->a_cnp); + if (!error) + union_removed_upper(un); union_unlock_upper(uppervp, td); } else { error = union_mkwhiteout( -- cgit v1.1