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From 0f6a5081d875051e1b6275096d25332e66f0458c Mon Sep 17 00:00:00 2001
From: Flavio Cruz <flaviocruz@gmail.com>
Date: Sun, 14 Feb 2016 18:37:16 -0500
Subject: [PATCH hurd 2/2] libdiskfs: fix and improve locking in nrefs/nput.
* libnetfs/node-nput.c: Do not unlock the node since it will be unlocked
later.
* libnetfs/node-nrele.c: Do not lock the node twice if not needed.
---
libdiskfs/node-nput.c | 1 -
libdiskfs/node-nrele.c | 8 ++++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/libdiskfs/node-nput.c b/libdiskfs/node-nput.c
index d23c103..d59769b 100644
--- a/libdiskfs/node-nput.c
+++ b/libdiskfs/node-nput.c
@@ -56,7 +56,6 @@ diskfs_nput (struct node *np)
hold a weak reference ourselves. */
diskfs_try_dropping_softrefs (np);
}
- pthread_mutex_unlock (&np->lock);
}
/* Finally get rid of our reference. */
diff --git a/libdiskfs/node-nrele.c b/libdiskfs/node-nrele.c
index d962846..a96d134 100644
--- a/libdiskfs/node-nrele.c
+++ b/libdiskfs/node-nrele.c
@@ -28,6 +28,7 @@
void
diskfs_nrele (struct node *np)
{
+ int locked = FALSE;
struct references result;
/* While we call the diskfs_try_dropping_softrefs, we need to hold
@@ -37,6 +38,7 @@ diskfs_nrele (struct node *np)
if (result.hard == 0)
{
+ locked = TRUE;
pthread_mutex_lock (&np->lock);
diskfs_lost_hardrefs (np);
if (!np->dn_stat.st_nlink)
@@ -49,7 +51,6 @@ diskfs_nrele (struct node *np)
hold a weak reference ourselves. */
diskfs_try_dropping_softrefs (np);
}
- pthread_mutex_unlock (&np->lock);
}
/* Finally get rid of our reference. */
@@ -57,7 +58,10 @@ diskfs_nrele (struct node *np)
if (result.hard == 0 && result.weak == 0)
{
- pthread_mutex_lock (&np->lock);
+ if (! locked)
+ pthread_mutex_lock (&np->lock);
diskfs_drop_node (np);
}
+ else if (locked)
+ pthread_mutex_unlock (&np->lock);
}
--
2.1.4
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