NFS: Remove BKL from NFS lookup code

All dentry-related operations are already BKL-safe, since they are
protected by the VFS locking. No extra locks should be needed in the NFS
code.

In the case of nfs_revalidate_inode(), we're only doing an attribute
update (protected by the inode->i_lock).
In the case of nfs_lookup(), we're instantiating a new dentry, so there
should be no contention possible until after we call d_materialise_unique.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 5ae8ee6..60da755 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -777,7 +777,6 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
        struct nfs_fattr fattr;
 
        parent = dget_parent(dentry);
-       lock_kernel();
        dir = parent->d_inode;
        nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
        inode = dentry->d_inode;
@@ -815,7 +814,6 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
 
        nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
  out_valid:
-       unlock_kernel();
        dput(parent);
        dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
                        __func__, dentry->d_parent->d_name.name,
@@ -834,7 +832,6 @@ out_zap_parent:
                shrink_dcache_parent(dentry);
        }
        d_drop(dentry);
-       unlock_kernel();
        dput(parent);
        dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
                        __func__, dentry->d_parent->d_name.name,
@@ -921,8 +918,6 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
        res = ERR_PTR(-ENOMEM);
        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
 
-       lock_kernel();
-
        /*
         * If we're doing an exclusive create, optimize away the lookup
         * but don't hash the dentry.
@@ -930,7 +925,7 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
        if (nfs_is_exclusive_create(dir, nd)) {
                d_instantiate(dentry, NULL);
                res = NULL;
-               goto out_unlock;
+               goto out;
        }
 
        parent = dentry->d_parent;
@@ -958,8 +953,6 @@ no_entry:
        nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
 out_unblock_sillyrename:
        nfs_unblock_sillyrename(parent);
-out_unlock:
-       unlock_kernel();
 out:
        return res;
 }