From c16eed2cb64089bf7d958db0fe85352f4ceefb4d Mon Sep 17 00:00:00 2001 From: Justus Winter <4winter@informatik.uni-hamburg.de> Date: Wed, 14 May 2014 11:19:35 +0200 Subject: libdiskfs: lock-less reference counting of nodes * libdiskfs/diskfs.h (struct node): Use refcounts_t for reference counting. (diskfs_node_refcnt_lock): Remove. (diskfs_node_norefs,diskfs_drop_node): Change comments accordingly. * libdiskfs/init-init.c: Adjust accordingly. * libdiskfs/node-drop.c: Likewise. * libdiskfs/node-make.c: Likewise. * libdiskfs/node-nput.c: Likewise. * libdiskfs/node-nputl.c: Likewise. * libdiskfs/node-nref.c: Likewise. * libdiskfs/node-nrefl.c: Likewise. * libdiskfs/node-nrele.c: Likewise. * libdiskfs/node-nrelel.c: Likewise. * ext2fs/inode.c: Likewise. * fatfs/inode.c: Likewise. * isofs/inode.c: Likewise. * tmpfs/node.c: Likewise. * doc/hurd.texi: Likewise. --- isofs/inode.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'isofs/inode.c') diff --git a/isofs/inode.c b/isofs/inode.c index 905d75c5..e79ebddb 100644 --- a/isofs/inode.c +++ b/isofs/inode.c @@ -60,7 +60,6 @@ struct node_cache static int node_cache_size = 0; static int node_cache_alloced = 0; struct node_cache *node_cache = 0; -/* nodecache_lock must be acquired before diskfs_node_refcnt_lock. */ static pthread_rwlock_t nodecache_lock = PTHREAD_RWLOCK_INITIALIZER; /* Forward */ @@ -564,14 +563,10 @@ diskfs_try_dropping_softrefs (struct node *np) /* Check if someone reacquired a reference through the node_cache. */ - unsigned int references; - pthread_spin_lock (&diskfs_node_refcnt_lock); - references = np->references; - pthread_spin_unlock (&diskfs_node_refcnt_lock); - - /* An additional reference is acquired by libdiskfs across calls - to diskfs_try_dropping_softrefs. */ - if (references > 1) + struct references result; + refcounts_references (&np->refcounts, &result); + + if (result.hard > 0) { /* A reference was reacquired through a hash table lookup. It's fine, we didn't touch anything yet. */ -- cgit v1.2.3