Commit e93a5e93 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Add support for application leases underpinned by a delegation 



If the NFSv4 client already holds a delegation for a file, then we can
support application leases (i.e. fcntl(fd, F_SETLEASE,...)) because the
underlying delegation guarantees that the file is not being modified on
the server by another client in a way that might conflict with the lease
guarantees.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 6b4befc0

fs/nfs/nfs4_fs.h

+2 −1
Original line number Diff line number Diff line
@@ -323,7 +323,8 @@ extern int update_open_stateid(struct nfs4_state *state, 
				const nfs4_stateid *open_stateid,

				const nfs4_stateid *deleg_stateid,

				fmode_t fmode);



extern int nfs4_proc_setlease(struct file *file, long arg,

			      struct file_lock **lease, void **priv);

extern int nfs4_proc_get_lease_time(struct nfs_client *clp,

		struct nfs_fsinfo *fsinfo);

extern void nfs4_update_changeattr(struct inode *dir,

fs/nfs/nfs4file.c

+7 −1
Original line number Diff line number Diff line
@@ -435,6 +435,12 @@ void nfs42_ssc_unregister_ops(void) 
}

#endif /* CONFIG_NFS_V4_2 */



static int nfs4_setlease(struct file *file, long arg, struct file_lock **lease,

			 void **priv)

{

	return nfs4_proc_setlease(file, arg, lease, priv);

}



const struct file_operations nfs4_file_operations = {

	.read_iter	= nfs_file_read,

	.write_iter	= nfs_file_write,
@@ -448,7 +454,7 @@ const struct file_operations nfs4_file_operations = { 
	.splice_read	= generic_file_splice_read,

	.splice_write	= iter_file_splice_write,

	.check_flags	= nfs_check_flags,

	.setlease	= simple_nosetlease,

	.setlease	= nfs4_setlease,

#ifdef CONFIG_NFS_V4_2

	.copy_file_range = nfs4_copy_file_range,

	.llseek		= nfs4_file_llseek,

fs/nfs/nfs4proc.c

+37 −0
Original line number Diff line number Diff line
@@ -7438,6 +7438,43 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) 
	return nfs4_retry_setlk(state, cmd, request);

}



static int nfs4_delete_lease(struct file *file, void **priv)

{

	return generic_setlease(file, F_UNLCK, NULL, priv);

}



static int nfs4_add_lease(struct file *file, long arg, struct file_lock **lease,

			  void **priv)

{

	struct inode *inode = file_inode(file);

	fmode_t type = arg == F_RDLCK ? FMODE_READ : FMODE_WRITE;

	int ret;



	/* No delegation, no lease */

	if (!nfs4_have_delegation(inode, type))

		return -ENOLCK;

	ret = generic_setlease(file, arg, lease, priv);

	if (ret || nfs4_have_delegation(inode, type))

		return ret;

	/* We raced with a delegation return */

	nfs4_delete_lease(file, priv);

	return -ENOLCK;

}



int nfs4_proc_setlease(struct file *file, long arg, struct file_lock **lease,

		       void **priv)

{

	switch (arg) {

	case F_RDLCK:

	case F_WRLCK:

		return nfs4_add_lease(file, arg, lease, priv);

	case F_UNLCK:

		return nfs4_delete_lease(file, priv);

	default:

		return -EINVAL;

	}

}



int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid)

{

	struct nfs_server *server = NFS_SERVER(state->inode);