[PATCH] VFS: Fix an error in unused dentry counting
With Vasily Averin <vvs@sw.ru>
Fix an error in unused dentry counting in shrink_dcache_for_umount_subtree()
in which the count is modified without the dcache_lock held.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Vasily Averin <vvs@sw.ru>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/dcache.c b/fs/dcache.c
index a5b76b6..fd4a428 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -557,6 +557,7 @@
static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
{
struct dentry *parent;
+ unsigned detached = 0;
BUG_ON(!IS_ROOT(dentry));
@@ -621,7 +622,7 @@
atomic_dec(&parent->d_count);
list_del(&dentry->d_u.d_child);
- dentry_stat.nr_dentry--; /* For d_free, below */
+ detached++;
inode = dentry->d_inode;
if (inode) {
@@ -639,7 +640,7 @@
* otherwise we ascend to the parent and move to the
* next sibling if there is one */
if (!parent)
- return;
+ goto out;
dentry = parent;
@@ -648,6 +649,11 @@
dentry = list_entry(dentry->d_subdirs.next,
struct dentry, d_u.d_child);
}
+out:
+ /* several dentries were freed, need to correct nr_dentry */
+ spin_lock(&dcache_lock);
+ dentry_stat.nr_dentry -= detached;
+ spin_unlock(&dcache_lock);
}
/*