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Fix an upper-vnode leak created in revision 1.52. When an upper-layer

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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.
This commit is contained in:
Brian Feldman 2004-01-16 16:31:01 +00:00
parent 33b53e37dc
commit 016344807a
2 changed files with 13 additions and 19 deletions
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27
sys/fs/unionfs/union_subr.c
View File

@ -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.

5
sys/fs/unionfs/union_vnops.c
View File

@ -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(