[PATCH 20/38] union-mount: Free union dirs on removal from dcache

From: Valerie Aurora
Date: Fri Jun 25 2010 - 15:11:22 EST


If a dentry is removed from dentry cache because its usage count drops
to zero, the union_dirs in its union stack are freed too.
---
fs/dcache.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 54ff5a3..ce54dc5 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -34,6 +34,7 @@
#include <linux/fs_struct.h>
#include <linux/hardirq.h>
#include "internal.h"
+#include "union.h"

int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
@@ -175,6 +176,7 @@ static struct dentry *d_kill(struct dentry *dentry)
dentry_stat.nr_dentry--; /* For d_free, below */
/*drops the locks, at that point nobody can reach this dentry */
dentry_iput(dentry);
+ d_free_unions(dentry);
if (IS_ROOT(dentry))
parent = NULL;
else
@@ -696,6 +698,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
iput(inode);
}

+ d_free_unions(dentry);
d_free(dentry);

/* finished when we fall off the top of the tree,
@@ -1535,6 +1538,7 @@ void d_delete(struct dentry * dentry)
isdir = S_ISDIR(dentry->d_inode->i_mode);
if (atomic_read(&dentry->d_count) == 1) {
dentry_iput(dentry);
+ d_free_unions(dentry);
fsnotify_nameremove(dentry, isdir);
return;
}
@@ -1545,6 +1549,13 @@ void d_delete(struct dentry * dentry)
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);

+ /*
+ * Remove any associated unions. While someone still has this
+ * directory open (ref count > 0), we could not have deleted
+ * it unless it was empty, and therefore has no references to
+ * directories below it. So we don't need the unions.
+ */
+ d_free_unions(dentry);
fsnotify_nameremove(dentry, isdir);
}
EXPORT_SYMBOL(d_delete);
--
1.6.3.3

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