nfs4proc.c

Linux Kernel 2.6.9 for OMAP1710

static int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(server,
				_nfs4_proc_getattr(server, fhandle, fattr),
				&exception);
	} while (exception.retry);
	return err;
}

/* 
 * The file is not closed if it is opened due to the a request to change
 * the size of the file. The open call will not be needed once the
 * VFS layer lookup-intents are implemented.
 *
 * Close is called when the inode is destroyed.
 * If we haven't opened the file for O_WRONLY, we
 * need to in the size_change case to obtain a stateid.
 *
 * Got race?
 * Because OPEN is always done by name in nfsv4, it is
 * possible that we opened a different file by the same
 * name.  We can recognize this race condition, but we
 * can't do anything about it besides returning an error.
 *
 * This will be fixed with VFS changes (lookup-intent).
 */
static int
nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
		  struct iattr *sattr)
{
	struct inode *		inode = dentry->d_inode;
	int			size_change = sattr->ia_valid & ATTR_SIZE;
	struct nfs4_state	*state = NULL;
	int need_iput = 0;
	int status;

	fattr->valid = 0;
	
	if (size_change) {
		struct rpc_cred *cred = rpcauth_lookupcred(NFS_SERVER(inode)->client->cl_auth, 0);
		state = nfs4_find_state(inode, cred, FMODE_WRITE);
		if (state == NULL) {
			state = nfs4_open_delegated(dentry->d_inode,
					FMODE_WRITE, cred);
			if (IS_ERR(state))
				state = nfs4_do_open(dentry->d_parent->d_inode,
						&dentry->d_name, FMODE_WRITE,
						NULL, cred);
			need_iput = 1;
		}
		put_rpccred(cred);
		if (IS_ERR(state))
			return PTR_ERR(state);

		if (state->inode != inode) {
			printk(KERN_WARNING "nfs: raced in setattr (%p != %p), returning -EIO\n", inode, state->inode);
			status = -EIO;
			goto out;
		}
	}
	status = nfs4_do_setattr(NFS_SERVER(inode), fattr,
			NFS_FH(inode), sattr, state);
out:
	if (state) {
		inode = state->inode;
		nfs4_close_state(state, FMODE_WRITE);
		if (need_iput)
			iput(inode);
	}
	return status;
}

static int _nfs4_proc_lookup(struct inode *dir, struct qstr *name,
		struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	int		       status;
	struct nfs_server *server = NFS_SERVER(dir);
	struct nfs4_lookup_arg args = {
		.bitmask = server->attr_bitmask,
		.dir_fh = NFS_FH(dir),
		.name = name,
	};
	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,
	};
	
	fattr->valid = 0;
	
	dprintk("NFS call  lookup %s\n", name->name);
	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	dprintk("NFS reply lookup: %d\n", status);
	return status;
}

static int nfs4_proc_lookup(struct inode *dir, struct qstr *name, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(dir),
				_nfs4_proc_lookup(dir, name, fhandle, fattr),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
{
	struct nfs4_accessargs args = {
		.fh = NFS_FH(inode),
	};
	struct nfs4_accessres res = { 0 };
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ACCESS],
		.rpc_argp = &args,
		.rpc_resp = &res,
		.rpc_cred = entry->cred,
	};
	int mode = entry->mask;
	int status;

	/*
	 * Determine which access bits we want to ask for...
	 */
	if (mode & MAY_READ)
		args.access |= NFS4_ACCESS_READ;
	if (S_ISDIR(inode->i_mode)) {
		if (mode & MAY_WRITE)
			args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE;
		if (mode & MAY_EXEC)
			args.access |= NFS4_ACCESS_LOOKUP;
	} else {
		if (mode & MAY_WRITE)
			args.access |= NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND;
		if (mode & MAY_EXEC)
			args.access |= NFS4_ACCESS_EXECUTE;
	}
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
	if (!status) {
		entry->mask = 0;
		if (res.access & NFS4_ACCESS_READ)
			entry->mask |= MAY_READ;
		if (res.access & (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE))
			entry->mask |= MAY_WRITE;
		if (res.access & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE))
			entry->mask |= MAY_EXEC;
	}
	return status;
}

static int nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(inode),
				_nfs4_proc_access(inode, entry),
				&exception);
	} while (exception.retry);
	return err;
}

/*
 * TODO: For the time being, we don't try to get any attributes
 * along with any of the zero-copy operations READ, READDIR,
 * READLINK, WRITE.
 *
 * In the case of the first three, we want to put the GETATTR
 * after the read-type operation -- this is because it is hard
 * to predict the length of a GETATTR response in v4, and thus
 * align the READ data correctly.  This means that the GETATTR
 * may end up partially falling into the page cache, and we should
 * shift it into the 'tail' of the xdr_buf before processing.
 * To do this efficiently, we need to know the total length
 * of data received, which doesn't seem to be available outside
 * of the RPC layer.
 *
 * In the case of WRITE, we also want to put the GETATTR after
 * the operation -- in this case because we want to make sure
 * we get the post-operation mtime and size.  This means that
 * we can't use xdr_encode_pages() as written: we need a variant
 * of it which would leave room in the 'tail' iovec.
 *
 * Both of these changes to the XDR layer would in fact be quite
 * minor, but I decided to leave them for a subsequent patch.
 */
static int _nfs4_proc_readlink(struct inode *inode, struct page *page,
		unsigned int pgbase, unsigned int pglen)
{
	struct nfs4_readlink args = {
		.fh       = NFS_FH(inode),
		.pgbase	  = pgbase,
		.pglen    = pglen,
		.pages    = &page,
	};
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READLINK],
		.rpc_argp = &args,
		.rpc_resp = NULL,
	};

	return rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
}

static int nfs4_proc_readlink(struct inode *inode, struct page *page,
		unsigned int pgbase, unsigned int pglen)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(inode),
				_nfs4_proc_readlink(inode, page, pgbase, pglen),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_read(struct nfs_read_data *rdata)
{
	int flags = rdata->flags;
	struct inode *inode = rdata->inode;
	struct nfs_fattr *fattr = rdata->res.fattr;
	struct nfs_server *server = NFS_SERVER(inode);
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_READ],
		.rpc_argp	= &rdata->args,
		.rpc_resp	= &rdata->res,
		.rpc_cred	= rdata->cred,
	};
	unsigned long timestamp = jiffies;
	int status;

	dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
			(long long) rdata->args.offset);

	fattr->valid = 0;
	status = rpc_call_sync(server->client, &msg, flags);
	if (!status)
		renew_lease(server, timestamp);
	dprintk("NFS reply read: %d\n", status);
	return status;
}

static int nfs4_proc_read(struct nfs_read_data *rdata)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(rdata->inode),
				_nfs4_proc_read(rdata),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_write(struct nfs_write_data *wdata)
{
	int rpcflags = wdata->flags;
	struct inode *inode = wdata->inode;
	struct nfs_fattr *fattr = wdata->res.fattr;
	struct nfs_server *server = NFS_SERVER(inode);
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_WRITE],
		.rpc_argp	= &wdata->args,
		.rpc_resp	= &wdata->res,
		.rpc_cred	= wdata->cred,
	};
	int status;

	dprintk("NFS call  write %d @ %Ld\n", wdata->args.count,
			(long long) wdata->args.offset);

	fattr->valid = 0;
	status = rpc_call_sync(server->client, &msg, rpcflags);
	dprintk("NFS reply write: %d\n", status);
	return status;
}

static int nfs4_proc_write(struct nfs_write_data *wdata)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(wdata->inode),
				_nfs4_proc_write(wdata),
				&exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_commit(struct nfs_write_data *cdata)
{
	struct inode *inode = cdata->inode;
	struct nfs_fattr *fattr = cdata->res.fattr;
	struct nfs_server *server = NFS_SERVER(inode);
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_COMMIT],
		.rpc_argp	= &cdata->args,
		.rpc_resp	= &cdata->res,
		.rpc_cred	= cdata->cred,
	};
	int status;

	dprintk("NFS call  commit %d @ %Ld\n", cdata->args.count,
			(long long) cdata->args.offset);

	fattr->valid = 0;
	status = rpc_call_sync(server->client, &msg, 0);
	dprintk("NFS reply commit: %d\n", status);
	return status;
}

static int nfs4_proc_commit(struct nfs_write_data *cdata)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(cdata->inode),
				_nfs4_proc_commit(cdata),
				&exception);
	} while (exception.retry);
	return err;
}

/*
 * Got race?
 * We will need to arrange for the VFS layer to provide an atomic open.
 * Until then, this create/open method is prone to inefficiency and race
 * conditions due to the lookup, create, and open VFS calls from sys_open()
 * placed on the wire.
 *
 * Given the above sorry state of affairs, I'm simply sending an OPEN.
 * The file will be opened again in the subsequent VFS open call
 * (nfs4_proc_file_open).
 *
 * The open for read will just hang around to be used by any process that
 * opens the file O_RDONLY. This will all be resolved with the VFS changes.
 */

static struct inode *
nfs4_proc_create(struct inode *dir, struct qstr *name, struct iattr *sattr,
                 int flags)
{
	struct inode *inode;
	struct nfs4_state *state = NULL;
	struct rpc_cred *cred;

	cred = rpcauth_lookupcred(NFS_SERVER(dir)->client->cl_auth, 0);
	state = nfs4_do_open(dir, name, flags, sattr, cred);
	put_rpccred(cred);
	if (!IS_ERR(state)) {
		inode = state->inode;
		if (flags & O_EXCL) {
			struct nfs_fattr fattr;
			int status;
			status = nfs4_do_setattr(NFS_SERVER(dir), &fattr,
			                     NFS_FH(inode), sattr, state);
			if (status != 0) {
				nfs4_close_state(state, flags);
				iput(inode);
				inode = ERR_PTR(status);
			}
		}
	} else
		inode = (struct inode *)state;
	return inode;
}

static int _nfs4_proc_remove(struct inode *dir, struct qstr *name)
{
	struct nfs4_remove_arg args = {
		.fh = NFS_FH(dir),
		.name = name,
	};
	struct nfs4_change_info	res;
	struct rpc_message msg = {
		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_REMOVE],
		.rpc_argp	= &args,
		.rpc_resp	= &res,
	};
	int			status;

	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	if (status == 0)
		update_changeattr(dir, &res);
	return status;
}

static int nfs4_proc_remove(struct inode *dir, struct qstr *name)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(dir),
				_nfs4_proc_remove(dir, name),
				&exception);
	} while (exception.retry);
	return err;
}

struct unlink_desc {
	struct nfs4_remove_arg	args;
	struct nfs4_change_info	res;
};

static int nfs4_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir,
		struct qstr *name)
{
	struct unlink_desc *up;

	up = (struct unlink_desc *) kmalloc(sizeof(*up), GFP_KERNEL);
	if (!up)
		return -ENOMEM;
	
	up->args.fh = NFS_FH(dir->d_inode);
	up->args.name = name;
	
	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE];
	msg->rpc_argp = &up->args;
	msg->rpc_resp = &up->res;
	return 0;
}

static int nfs4_proc_unlink_done(struct dentry *dir, struct rpc_task *task)
{
	struct rpc_message *msg = &task->tk_msg;
	struct unlink_desc *up;
	
	if (msg->rpc_resp != NULL) {
		up = container_of(msg->rpc_resp, struct unlink_desc, res);
		update_changeattr(dir->d_inode, &up->res);
		kfree(up);
		msg->rpc_resp = NULL;
		msg->rpc_argp = NULL;
	}
	return 0;
}

static int _nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,
		struct inode *new_dir, struct qstr *new_name)
{
	struct nfs4_rename_arg arg = {
		.old_dir = NFS_FH(old_dir),
		.new_dir = NFS_FH(new_dir),
		.old_name = old_name,
		.new_name = new_name,
	};
	struct nfs4_rename_res res = { };
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RENAME],
		.rpc_argp = &arg,
		.rpc_resp = &res,
	};
	int			status;
	
	status = rpc_call_sync(NFS_CLIENT(old_dir), &msg, 0);

	if (!status) {
		update_changeattr(old_dir, &res.old_cinfo);
		update_changeattr(new_dir, &res.new_cinfo);
	}
	return status;
}

static int nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,
		struct inode *new_dir, struct qstr *new_name)
{
	struct nfs4_exception exception = { };
	int err;
	do {
		err = nfs4_handle_exception(NFS_SERVER(old_dir),
				_nfs4_proc_rename(old_dir, old_name,
					new_dir, new_name),
				&exception);
	} while (exception.retry);
	return err;
}