nfs4proc.c

Linux Kernel 2.6.9 for OMAP1710

	};
	struct nfs_openargs o_arg = {
		.fh             = NFS_FH(dir),
		.open_flags	= flags,
		.name           = name,
		.server         = server,
		.bitmask = server->attr_bitmask,
		.claim = NFS4_OPEN_CLAIM_NULL,
	};
	struct nfs_openres o_res = {
		.f_attr         = &f_attr,
		.server         = server,
	};
	struct rpc_message msg = {
		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN],
		.rpc_argp       = &o_arg,
		.rpc_resp       = &o_res,
		.rpc_cred	= cred,
	};

	/* Protect against reboot recovery conflicts */
	down_read(&clp->cl_sem);
	status = -ENOMEM;
	if (!(sp = nfs4_get_state_owner(server, cred))) {
		dprintk("nfs4_do_open: nfs4_get_state_owner failed!\n");
		goto out_err;
	}
	if (flags & O_EXCL) {
		u32 *p = (u32 *) o_arg.u.verifier.data;
		p[0] = jiffies;
		p[1] = current->pid;
	} else
		o_arg.u.attrs = sattr;
	/* Serialization for the sequence id */
	down(&sp->so_sema);
	o_arg.seqid = sp->so_seqid;
	o_arg.id = sp->so_id;
	o_arg.clientid = clp->cl_clientid,

	status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
	nfs4_increment_seqid(status, sp);
	if (status)
		goto out_err;
	update_changeattr(dir, &o_res.cinfo);
	if(o_res.rflags & NFS4_OPEN_RESULT_CONFIRM) {
		status = _nfs4_proc_open_confirm(server->client, &o_res.fh,
				sp, &o_res.stateid);
		if (status != 0)
			goto out_err;
	}
	if (!(f_attr.valid & NFS_ATTR_FATTR)) {
		status = server->rpc_ops->getattr(server, &o_res.fh, &f_attr);
		if (status < 0)
			goto out_err;
	}

	status = -ENOMEM;
	inode = nfs_fhget(dir->i_sb, &o_res.fh, &f_attr);
	if (!inode)
		goto out_err;
	state = nfs4_get_open_state(inode, sp);
	if (!state)
		goto out_err;
	memcpy(&state->stateid, &o_res.stateid, sizeof(state->stateid));
	spin_lock(&inode->i_lock);
	if (flags & FMODE_READ)
		state->nreaders++;
	if (flags & FMODE_WRITE)
		state->nwriters++;
	state->state |= flags & (FMODE_READ|FMODE_WRITE);
	spin_unlock(&inode->i_lock);
	if (o_res.delegation_type != 0)
		nfs_inode_set_delegation(inode, cred, &o_res);
	up(&sp->so_sema);
	nfs4_put_state_owner(sp);
	up_read(&clp->cl_sem);
	*res = state;
	return 0;
out_err:
	if (sp != NULL) {
		if (state != NULL)
			nfs4_put_open_state(state);
		up(&sp->so_sema);
		nfs4_put_state_owner(sp);
	}
	/* Note: clp->cl_sem must be released before nfs4_put_open_state()! */
	up_read(&clp->cl_sem);
	if (inode != NULL)
		iput(inode);
	*res = NULL;
	return status;
}


struct nfs4_state *nfs4_do_open(struct inode *dir, struct qstr *name, int flags, struct iattr *sattr, struct rpc_cred *cred)
{
	struct nfs4_exception exception = { };
	struct nfs4_state *res;
	int status;

	do {
		status = _nfs4_do_open(dir, name, flags, sattr, cred, &res);
		if (status == 0)
			break;
		/* NOTE: BAD_SEQID means the server and client disagree about the
		 * book-keeping w.r.t. state-changing operations
		 * (OPEN/CLOSE/LOCK/LOCKU...)
		 * It is actually a sign of a bug on the client or on the server.
		 *
		 * If we receive a BAD_SEQID error in the particular case of
		 * doing an OPEN, we assume that nfs4_increment_seqid() will
		 * have unhashed the old state_owner for us, and that we can
		 * therefore safely retry using a new one. We should still warn
		 * the user though...
		 */
		if (status == -NFS4ERR_BAD_SEQID) {
			printk(KERN_WARNING "NFS: v4 server returned a bad sequence-id error!\n");
			exception.retry = 1;
			continue;
		}
		res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(dir),
					status, &exception));
	} while (exception.retry);
	return res;
}

static int _nfs4_do_setattr(struct nfs_server *server, struct nfs_fattr *fattr,
                struct nfs_fh *fhandle, struct iattr *sattr,
                struct nfs4_state *state)
{
        struct nfs_setattrargs  arg = {
                .fh             = fhandle,
                .iap            = sattr,
		.server		= server,
		.bitmask = server->attr_bitmask,
        };
        struct nfs_setattrres  res = {
		.fattr		= fattr,
		.server		= server,
        };
        struct rpc_message msg = {
                .rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
                .rpc_argp       = &arg,
                .rpc_resp       = &res,
        };

        fattr->valid = 0;

	if (sattr->ia_valid & ATTR_SIZE)
		nfs4_copy_stateid(&arg.stateid, state, NULL);
	else
		memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));

	return rpc_call_sync(server->client, &msg, 0);
}

int nfs4_do_setattr(struct nfs_server *server, struct nfs_fattr *fattr,
                struct nfs_fh *fhandle, struct iattr *sattr,
                struct nfs4_state *state)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(server,
				_nfs4_do_setattr(server, fattr, fhandle, sattr,
					state),
				&exception);
	} while (exception.retry);
	return err;
}

/* 
 * It is possible for data to be read/written from a mem-mapped file 
 * after the sys_close call (which hits the vfs layer as a flush).
 * This means that we can't safely call nfsv4 close on a file until 
 * the inode is cleared. This in turn means that we are not good
 * NFSv4 citizens - we do not indicate to the server to update the file's 
 * share state even when we are done with one of the three share 
 * stateid's in the inode.
 *
 * NOTE: Caller must be holding the sp->so_owner semaphore!
 */
static int _nfs4_do_close(struct inode *inode, struct nfs4_state *state) 
{
	struct nfs4_state_owner *sp = state->owner;
	int status = 0;
	struct nfs_closeargs arg = {
		.fh		= NFS_FH(inode),
	};
	struct nfs_closeres res;
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_CLOSE],
		.rpc_argp	= &arg,
		.rpc_resp	= &res,
	};

	if (test_bit(NFS_DELEGATED_STATE, &state->flags))
		return 0;
	memcpy(&arg.stateid, &state->stateid, sizeof(arg.stateid));
	/* Serialization for the sequence id */
	arg.seqid = sp->so_seqid,
	status = rpc_call_sync(NFS_SERVER(inode)->client, &msg, RPC_TASK_NOINTR);

        /* hmm. we are done with the inode, and in the process of freeing
	 * the state_owner. we keep this around to process errors
	 */
	nfs4_increment_seqid(status, sp);
	if (!status)
		memcpy(&state->stateid, &res.stateid, sizeof(state->stateid));

	return status;
}

int nfs4_do_close(struct inode *inode, struct nfs4_state *state) 
{
	struct nfs_server *server = NFS_SERVER(state->inode);
	struct nfs4_exception exception = { };
	int err;
	do {
		err = _nfs4_do_close(inode, state);
		switch (err) {
			case -NFS4ERR_STALE_STATEID:
			case -NFS4ERR_EXPIRED:
				nfs4_schedule_state_recovery(server->nfs4_state);
				err = 0;
			default:
				state->state = 0;
		}
		err = nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_do_downgrade(struct inode *inode, struct nfs4_state *state, mode_t mode) 
{
	struct nfs4_state_owner *sp = state->owner;
	int status = 0;
	struct nfs_closeargs arg = {
		.fh		= NFS_FH(inode),
		.seqid		= sp->so_seqid,
		.open_flags	= mode,
	};
	struct nfs_closeres res;
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE],
		.rpc_argp	= &arg,
		.rpc_resp	= &res,
	};

	if (test_bit(NFS_DELEGATED_STATE, &state->flags))
		return 0;
	memcpy(&arg.stateid, &state->stateid, sizeof(arg.stateid));
	status = rpc_call_sync(NFS_SERVER(inode)->client, &msg, RPC_TASK_NOINTR);
	nfs4_increment_seqid(status, sp);
	if (!status)
		memcpy(&state->stateid, &res.stateid, sizeof(state->stateid));

	return status;
}

int nfs4_do_downgrade(struct inode *inode, struct nfs4_state *state, mode_t mode) 
{
	struct nfs_server *server = NFS_SERVER(state->inode);
	struct nfs4_exception exception = { };
	int err;
	do {
		err = _nfs4_do_downgrade(inode, state, mode);
		switch (err) {
			case -NFS4ERR_STALE_STATEID:
			case -NFS4ERR_EXPIRED:
				nfs4_schedule_state_recovery(server->nfs4_state);
				err = 0;
			default:
				state->state = mode;
		}
		err = nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

struct inode *
nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	struct iattr attr;
	struct rpc_cred *cred;
	struct nfs4_state *state;

	if (nd->flags & LOOKUP_CREATE) {
		attr.ia_mode = nd->intent.open.create_mode;
		attr.ia_valid = ATTR_MODE;
		if (!IS_POSIXACL(dir))
			attr.ia_mode &= ~current->fs->umask;
	} else {
		attr.ia_valid = 0;
		BUG_ON(nd->intent.open.flags & O_CREAT);
	}

	cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
	state = nfs4_do_open(dir, &dentry->d_name, nd->intent.open.flags, &attr, cred);
	put_rpccred(cred);
	if (IS_ERR(state))
		return (struct inode *)state;
	return state->inode;
}

int
nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags)
{
	struct rpc_cred *cred;
	struct nfs4_state *state;
	struct inode *inode;

	cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
	state = nfs4_open_delegated(dentry->d_inode, openflags, cred);
	if (IS_ERR(state))
		state = nfs4_do_open(dir, &dentry->d_name, openflags, NULL, cred);
	put_rpccred(cred);
	if (state == ERR_PTR(-ENOENT) && dentry->d_inode == 0)
		return 1;
	if (IS_ERR(state))
		return 0;
	inode = state->inode;
	if (inode == dentry->d_inode) {
		iput(inode);
		return 1;
	}
	d_drop(dentry);
	nfs4_close_state(state, openflags);
	iput(inode);
	return 0;
}


static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
{
	struct nfs4_server_caps_res res = {};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SERVER_CAPS],
		.rpc_argp = fhandle,
		.rpc_resp = &res,
	};
	int status;

	status = rpc_call_sync(server->client, &msg, 0);
	if (status == 0) {
		memcpy(server->attr_bitmask, res.attr_bitmask, sizeof(server->attr_bitmask));
		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL)
			server->caps |= NFS_CAP_ACLS;
		if (res.has_links != 0)
			server->caps |= NFS_CAP_HARDLINKS;
		if (res.has_symlinks != 0)
			server->caps |= NFS_CAP_SYMLINKS;
		server->acl_bitmask = res.acl_bitmask;
	}
	return status;
}

static int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(server,
				_nfs4_server_capabilities(server, fhandle),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
		struct nfs_fsinfo *info)
{
	struct nfs_fattr *	fattr = info->fattr;
	struct nfs4_lookup_root_arg args = {
		.bitmask = nfs4_fattr_bitmap,
	};
	struct nfs4_lookup_res res = {
		.server = server,
		.fattr = fattr,
		.fh = fhandle,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP_ROOT],
		.rpc_argp = &args,
		.rpc_resp = &res,
	};
	fattr->valid = 0;
	return rpc_call_sync(server->client, &msg, 0);
}

static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
		struct nfs_fsinfo *info)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(server,
				_nfs4_lookup_root(server, fhandle, info),
				&exception);
	} while (exception.retry);
	return err;
}

static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
		struct nfs_fsinfo *info)
{
	struct nfs_fattr *	fattr = info->fattr;
	unsigned char *		p;
	struct qstr		q;
	struct nfs4_lookup_arg args = {
		.dir_fh = fhandle,
		.name = &q,
		.bitmask = nfs4_fattr_bitmap,
	};
	struct nfs4_lookup_res res = {
		.server = server,
		.fattr = fattr,
		.fh = fhandle,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP],
		.rpc_argp = &args,
		.rpc_resp = &res,
	};
	int status;

	/*
	 * Now we do a separate LOOKUP for each component of the mount path.
	 * The LOOKUPs are done separately so that we can conveniently
	 * catch an ERR_WRONGSEC if it occurs along the way...
	 */
	status = nfs4_lookup_root(server, fhandle, info);
	if (status)
		goto out;

	p = server->mnt_path;
	for (;;) {
		struct nfs4_exception exception = { };

		while (*p == '/')
			p++;
		if (!*p)
			break;
		q.name = p;
		while (*p && (*p != '/'))
			p++;
		q.len = p - q.name;

		do {
			fattr->valid = 0;
			status = nfs4_handle_exception(server,
					rpc_call_sync(server->client, &msg, 0),
					&exception);
		} while (exception.retry);
		if (status == 0)
			continue;
		if (status == -ENOENT) {
			printk(KERN_NOTICE "NFS: mount path %s does not exist!\n", server->mnt_path);
			printk(KERN_NOTICE "NFS: suggestion: try mounting '/' instead.\n");
		}
		break;
	}
	if (status == 0)
		status = nfs4_server_capabilities(server, fhandle);
	if (status == 0)
		status = nfs4_do_fsinfo(server, fhandle, info);
out:
	return status;
}

static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs4_getattr_arg args = {
		.fh = fhandle,
		.bitmask = server->attr_bitmask,
	};
	struct nfs4_getattr_res res = {
		.fattr = fattr,
		.server = server,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETATTR],
		.rpc_argp = &args,
		.rpc_resp = &res,
	};
	
	fattr->valid = 0;
	return rpc_call_sync(server->client, &msg, 0);
}