Commit fc0f684c authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent fc81af53

fs/nfs/dir.c

+1 −8
Original line number Diff line number Diff line
@@ -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;

}

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