fs: dcache scale dentry refcount

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 8c8afc716b98..18aee04a8411 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -280,7 +280,7 @@ static int remove_file(struct dentry *parent, char *name)
         spin_lock(&dcache_lock);
         spin_lock(&tmp->d_lock);
         if (!(d_unhashed(tmp) && tmp->d_inode)) {
-                dget_locked(tmp);
+                dget_locked_dlock(tmp);
                 __d_drop(tmp);
                 spin_unlock(&tmp->d_lock);
                 spin_unlock(&dcache_lock);
diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index f99bddc01716..fe4b242f0094 100644
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -456,7 +456,7 @@ static int remove_file(struct dentry *parent, char *name)
         spin_lock(&dcache_lock);
         spin_lock(&tmp->d_lock);
         if (!(d_unhashed(tmp) && tmp->d_inode)) {
-                dget_locked(tmp);
+                dget_locked_dlock(tmp);
                 __d_drop(tmp);
                 spin_unlock(&tmp->d_lock);
                 spin_unlock(&dcache_lock);