diff options
| -rw-r--r-- | trans/fakeroot.c | 71 |
1 files changed, 50 insertions, 21 deletions
diff --git a/trans/fakeroot.c b/trans/fakeroot.c index 12331047..eff52258 100644 --- a/trans/fakeroot.c +++ b/trans/fakeroot.c @@ -128,6 +128,31 @@ void netfs_node_norefs (struct node *np) { assert (np->nn->np == np); + mach_port_deallocate (mach_task_self (), np->nn->file); + mach_port_deallocate (mach_task_self (), np->nn->idport); + free (np->nn); + free (np); +} + +/* This is the cleanup function we install in netfs_protid_class. If + the associated nodes reference count would also drop to zero, and + the node has no faked attributes, we destroy it as well. */ +static void +fakeroot_netfs_release_protid (void *cookie) +{ + struct node *np = ((struct protid *) cookie)->po->np; + assert (np->nn->np == np); + + pthread_mutex_lock (&idport_ihash_lock); + pthread_mutex_lock (&np->lock); + + assert ((np->nn->faked & FAKE_REFERENCE) == 0); + + /* Check if someone else reacquired a reference to the node besides + ours that is about to be dropped. */ + if (np->references > 1) + goto out; + if (np->nn->faked != 0 && netfs_validate_stat (np, 0) == 0 && np->nn_stat.st_nlink > 0) { @@ -139,30 +164,24 @@ netfs_node_norefs (struct node *np) until this fakeroot filesystem dies. One easy solution would be to scan nodes with references=1 for st_nlink=0 at some convenient time, periodically or in syncfs. */ - if ((np->nn->faked & FAKE_REFERENCE) == 0) - { - np->nn->faked |= FAKE_REFERENCE; - ++np->references; - } - pthread_mutex_unlock (&np->lock); - return; - } - pthread_spin_unlock (&netfs_node_refcnt_lock); /* Avoid deadlock. */ - pthread_mutex_lock (&idport_ihash_lock); - pthread_spin_lock (&netfs_node_refcnt_lock); - /* Previous holder of this lock might have just got a reference. */ - if (np->references > 0) - { - pthread_mutex_unlock (&idport_ihash_lock); - return; + /* Keep a fake reference. */ + netfs_nref (np); + + /* Set the FAKE_REFERENCE flag so that we can properly + account for that fake reference. */ + np->nn->faked |= FAKE_REFERENCE; + + /* We keep our node. */ + goto out; } + hurd_ihash_locp_remove (&idport_ihash, np->nn->idport_locp); + + out: + pthread_mutex_unlock (&np->lock); + netfs_release_protid (cookie); pthread_mutex_unlock (&idport_ihash_lock); - mach_port_deallocate (mach_task_self (), np->nn->file); - mach_port_deallocate (mach_task_self (), np->nn->idport); - free (np->nn); - free (np); } /* Given an existing node, make sure it has NEWMODES in its openmodes. @@ -326,7 +345,14 @@ netfs_S_dir_lookup (struct protid *diruser, pthread_mutex_lock (&np->lock); err = check_openmodes (np->nn, (flags & (O_RDWR|O_EXEC)), file); if (!err) - netfs_nref (np); + { + /* If the looked-up file carries a fake reference, we + use that and clear the FAKE_REFERENCE flag. */ + if (np->nn->faked & FAKE_REFERENCE) + np->nn->faked &= ~FAKE_REFERENCE; + else + netfs_nref (np); + } pthread_mutex_unlock (&np->lock); pthread_mutex_unlock (&idport_ihash_lock); } @@ -957,6 +983,9 @@ any user to open nodes regardless of permissions as is done for root." }; task_get_bootstrap_port (mach_task_self (), &bootstrap); netfs_init (); + /* Install our own clean routine. */ + netfs_protid_class->clean_routine = fakeroot_netfs_release_protid; + /* Get our underlying node (we presume it's a directory) and use that to make the root node of the filesystem. */ err = new_node (netfs_startup (bootstrap, O_READ), MACH_PORT_NULL, 0, O_READ, |