diff options
Diffstat (limited to 'libdiskfs/node-nrele.c')
-rw-r--r-- | libdiskfs/node-nrele.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/libdiskfs/node-nrele.c b/libdiskfs/node-nrele.c new file mode 100644 index 00000000..9dbc5d8c --- /dev/null +++ b/libdiskfs/node-nrele.c @@ -0,0 +1,65 @@ +/* + Copyright (C) 1999 Free Software Foundation, Inc. + Written by Thomas Bushnell, BSG. + + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */ + +#include "priv.h" + +/* Release a hard reference on NP. If NP is locked by anyone, then + this cannot be the last hard reference (because you must hold a + hard reference in order to hold the lock). If this is the last + hard reference and there are no links, then request soft references + to be dropped. */ +void +diskfs_nrele (struct node *np) +{ + int tried_drop_softrefs = 0; + + loop: + spin_lock (&diskfs_node_refcnt_lock); + assert (np->references); + np->references--; + if (np->references + np->light_references == 0) + { + mutex_lock (&np->lock); + diskfs_drop_node (np); + } + else if (np->references == 0) + { + mutex_lock (&np->lock); + spin_unlock (&diskfs_node_refcnt_lock); + diskfs_lost_hardrefs (np); + if (!np->dn_stat.st_nlink && !tried_drop_softrefs) + { + /* Same issue here as in nput; see that for explanation */ + spin_lock (&diskfs_node_refcnt_lock); + np->references++; + spin_unlock (&diskfs_node_refcnt_lock); + + diskfs_try_dropping_softrefs (np); + tried_drop_softrefs = 1; + + /* Now we can drop the reference back... */ + mutex_unlock (&np->lock); + goto loop; + } + mutex_unlock (&np->lock); + } + else + spin_unlock (&diskfs_node_refcnt_lock); +} |