Commit 669c0580 authored by Anna Schumaker's avatar Anna Schumaker Committed by Trond Myklebust
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NFS: Shortcut lookup revalidations if we have a directory delegation 



Holding a directory delegation means we know that nobody else has
modified the directory on the server, so we can take a few revalidation
shortcuts.

Signed-off-by: default avatarAnna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 2da21167

fs/nfs/delegation.h

+5 −0
Original line number Diff line number Diff line
@@ -130,6 +130,11 @@ static inline void nfs_request_directory_delegation(struct inode *inode) 
		set_bit(NFS_INO_REQ_DIR_DELEG, &NFS_I(inode)->flags);

}



static inline bool nfs_have_directory_delegation(struct inode *inode)

{

	return S_ISDIR(inode->i_mode) && nfs_have_delegated_attributes(inode);

}



int nfs4_delegation_hash_alloc(struct nfs_server *server);



#endif

fs/nfs/dir.c

+19 −0
Original line number Diff line number Diff line
@@ -1515,6 +1515,15 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry, 
		return 0;

	if (!nfs_dentry_verify_change(dir, dentry))

		return 0;



	/*

	 * If we have a directory delegation then we don't need to revalidate

	 * the directory. The delegation will either get recalled or we will

	 * receive a notification when it changes.

	 */

	if (nfs_have_directory_delegation(dir))

		return 0;



	/* Revalidate nfsi->cache_change_attribute before we declare a match */

	if (nfs_mapping_need_revalidate_inode(dir)) {

		if (rcu_walk)
@@ -2207,6 +2216,13 @@ int nfs_atomic_open(struct inode *dir, struct dentry *dentry, 
}

EXPORT_SYMBOL_GPL(nfs_atomic_open);



static int

nfs_lookup_revalidate_delegated_parent(struct inode *dir, struct dentry *dentry,

				       struct inode *inode)

{

	return nfs_lookup_revalidate_done(dir, dentry, inode, 1);

}



static int

nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name,

		       struct dentry *dentry, unsigned int flags)
@@ -2234,6 +2250,9 @@ nfs4_lookup_revalidate(struct inode *dir, const struct qstr *name, 
	if (nfs_verifier_is_delegated(dentry))

		return nfs_lookup_revalidate_delegated(dir, dentry, inode);



	if (nfs_have_directory_delegation(dir))

		return nfs_lookup_revalidate_delegated_parent(dir, dentry, inode);



	/* NFS only supports OPEN on regular files */

	if (!S_ISREG(inode->i_mode))

		goto full_reval;

fs/nfs/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -1389,6 +1389,9 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode) 
		status = pnfs_sync_inode(inode, false);

		if (status)

			goto out;

	} else if (nfs_have_directory_delegation(inode)) {

		status = 0;

		goto out;

	}



	status = -ENOMEM;