nfs4proc.c

linux 内核源代码

		nfs_post_op_update_inode(dir, o_res->dir_attr);
	} else
		nfs_refresh_inode(dir, o_res->dir_attr);
	if(o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
		status = _nfs4_proc_open_confirm(data);
		if (status != 0)
			return status;
	}
	if (!(o_res->f_attr->valid & NFS_ATTR_FATTR))
		_nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr);
	return 0;
}

static int nfs4_recover_expired_lease(struct nfs_server *server)
{
	struct nfs_client *clp = server->nfs_client;
	int ret;

	for (;;) {
		ret = nfs4_wait_clnt_recover(server->client, clp);
		if (ret != 0)
			return ret;
		if (!test_and_clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
			break;
		nfs4_schedule_state_recovery(clp);
	}
	return 0;
}

/*
 * OPEN_EXPIRED:
 * 	reclaim state on the server after a network partition.
 * 	Assumes caller holds the appropriate lock
 */
static int _nfs4_open_expired(struct nfs_open_context *ctx, struct nfs4_state *state)
{
	struct nfs4_opendata *opendata;
	int ret;

	opendata = nfs4_open_recoverdata_alloc(ctx, state);
	if (IS_ERR(opendata))
		return PTR_ERR(opendata);
	ret = nfs4_open_recover(opendata, state);
	if (ret == -ESTALE) {
		/* Invalidate the state owner so we don't ever use it again */
		nfs4_drop_state_owner(state->owner);
		d_drop(ctx->path.dentry);
	}
	nfs4_opendata_put(opendata);
	return ret;
}

static inline int nfs4_do_open_expired(struct nfs_open_context *ctx, struct nfs4_state *state)
{
	struct nfs_server *server = NFS_SERVER(state->inode);
	struct nfs4_exception exception = { };
	int err;

	do {
		err = _nfs4_open_expired(ctx, state);
		if (err == -NFS4ERR_DELAY)
			nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
	struct nfs_open_context *ctx;
	int ret;

	ctx = nfs4_state_find_open_context(state);
	if (IS_ERR(ctx))
		return PTR_ERR(ctx);
	ret = nfs4_do_open_expired(ctx, state);
	put_nfs_open_context(ctx);
	return ret;
}

/*
 * on an EXCLUSIVE create, the server should send back a bitmask with FATTR4-*
 * fields corresponding to attributes that were used to store the verifier.
 * Make sure we clobber those fields in the later setattr call
 */
static inline void nfs4_exclusive_attrset(struct nfs4_opendata *opendata, struct iattr *sattr)
{
	if ((opendata->o_res.attrset[1] & FATTR4_WORD1_TIME_ACCESS) &&
	    !(sattr->ia_valid & ATTR_ATIME_SET))
		sattr->ia_valid |= ATTR_ATIME;

	if ((opendata->o_res.attrset[1] & FATTR4_WORD1_TIME_MODIFY) &&
	    !(sattr->ia_valid & ATTR_MTIME_SET))
		sattr->ia_valid |= ATTR_MTIME;
}

/*
 * Returns a referenced nfs4_state
 */
static int _nfs4_do_open(struct inode *dir, struct path *path, int flags, struct iattr *sattr, struct rpc_cred *cred, struct nfs4_state **res)
{
	struct nfs4_state_owner  *sp;
	struct nfs4_state     *state = NULL;
	struct nfs_server       *server = NFS_SERVER(dir);
	struct nfs_client *clp = server->nfs_client;
	struct nfs4_opendata *opendata;
	int status;

	/* Protect against reboot recovery conflicts */
	status = -ENOMEM;
	if (!(sp = nfs4_get_state_owner(server, cred))) {
		dprintk("nfs4_do_open: nfs4_get_state_owner failed!\n");
		goto out_err;
	}
	status = nfs4_recover_expired_lease(server);
	if (status != 0)
		goto err_put_state_owner;
	if (path->dentry->d_inode != NULL)
		nfs4_return_incompatible_delegation(path->dentry->d_inode, flags & (FMODE_READ|FMODE_WRITE));
	down_read(&clp->cl_sem);
	status = -ENOMEM;
	opendata = nfs4_opendata_alloc(path, sp, flags, sattr);
	if (opendata == NULL)
		goto err_release_rwsem;

	if (path->dentry->d_inode != NULL)
		opendata->state = nfs4_get_open_state(path->dentry->d_inode, sp);

	status = _nfs4_proc_open(opendata);
	if (status != 0)
		goto err_opendata_put;

	if (opendata->o_arg.open_flags & O_EXCL)
		nfs4_exclusive_attrset(opendata, sattr);

	state = nfs4_opendata_to_nfs4_state(opendata);
	status = PTR_ERR(state);
	if (IS_ERR(state))
		goto err_opendata_put;
	nfs4_opendata_put(opendata);
	nfs4_put_state_owner(sp);
	up_read(&clp->cl_sem);
	*res = state;
	return 0;
err_opendata_put:
	nfs4_opendata_put(opendata);
err_release_rwsem:
	up_read(&clp->cl_sem);
err_put_state_owner:
	nfs4_put_state_owner(sp);
out_err:
	*res = NULL;
	return status;
}


static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, 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, path, 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 nfs_increment_open_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 %s "
					" returned a bad sequence-id error!\n",
					NFS_SERVER(dir)->nfs_client->cl_hostname);
			exception.retry = 1;
			continue;
		}
		/*
		 * BAD_STATEID on OPEN means that the server cancelled our
		 * state before it received the OPEN_CONFIRM.
		 * Recover by retrying the request as per the discussion
		 * on Page 181 of RFC3530.
		 */
		if (status == -NFS4ERR_BAD_STATEID) {
			exception.retry = 1;
			continue;
		}
		if (status == -EAGAIN) {
			/* We must have found a delegation */
			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 inode *inode, struct nfs_fattr *fattr,
                struct iattr *sattr, struct nfs4_state *state)
{
	struct nfs_server *server = NFS_SERVER(inode);
        struct nfs_setattrargs  arg = {
                .fh             = NFS_FH(inode),
                .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,
        };
	unsigned long timestamp = jiffies;
	int status;

	nfs_fattr_init(fattr);

	if (nfs4_copy_delegation_stateid(&arg.stateid, inode)) {
		/* Use that stateid */
	} else if (state != NULL) {
		msg.rpc_cred = state->owner->so_cred;
		nfs4_copy_stateid(&arg.stateid, state, current->files);
	} else
		memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));

	status = rpc_call_sync(server->client, &msg, 0);
	if (status == 0 && state != NULL)
		renew_lease(server, timestamp);
	return status;
}

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

struct nfs4_closedata {
	struct path path;
	struct inode *inode;
	struct nfs4_state *state;
	struct nfs_closeargs arg;
	struct nfs_closeres res;
	struct nfs_fattr fattr;
	unsigned long timestamp;
};

static void nfs4_free_closedata(void *data)
{
	struct nfs4_closedata *calldata = data;
	struct nfs4_state_owner *sp = calldata->state->owner;

	nfs4_put_open_state(calldata->state);
	nfs_free_seqid(calldata->arg.seqid);
	nfs4_put_state_owner(sp);
	dput(calldata->path.dentry);
	mntput(calldata->path.mnt);
	kfree(calldata);
}

static void nfs4_close_done(struct rpc_task *task, void *data)
{
	struct nfs4_closedata *calldata = data;
	struct nfs4_state *state = calldata->state;
	struct nfs_server *server = NFS_SERVER(calldata->inode);

	if (RPC_ASSASSINATED(task))
		return;
        /* hmm. we are done with the inode, and in the process of freeing
	 * the state_owner. we keep this around to process errors
	 */
	nfs_increment_open_seqid(task->tk_status, calldata->arg.seqid);
	switch (task->tk_status) {
		case 0:
			nfs_set_open_stateid(state, &calldata->res.stateid, 0);
			renew_lease(server, calldata->timestamp);
			break;
		case -NFS4ERR_STALE_STATEID:
		case -NFS4ERR_EXPIRED:
			break;
		default:
			if (nfs4_async_handle_error(task, server) == -EAGAIN) {
				rpc_restart_call(task);
				return;
			}
	}
	nfs_refresh_inode(calldata->inode, calldata->res.fattr);
}

static void nfs4_close_prepare(struct rpc_task *task, void *data)
{
	struct nfs4_closedata *calldata = data;
	struct nfs4_state *state = calldata->state;
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE],
		.rpc_argp = &calldata->arg,
		.rpc_resp = &calldata->res,
		.rpc_cred = state->owner->so_cred,
	};
	int clear_rd, clear_wr, clear_rdwr;

	if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
		return;

	clear_rd = clear_wr = clear_rdwr = 0;
	spin_lock(&state->owner->so_lock);
	/* Calculate the change in open mode */
	if (state->n_rdwr == 0) {
		if (state->n_rdonly == 0) {
			clear_rd |= test_and_clear_bit(NFS_O_RDONLY_STATE, &state->flags);
			clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags);
		}
		if (state->n_wronly == 0) {
			clear_wr |= test_and_clear_bit(NFS_O_WRONLY_STATE, &state->flags);
			clear_rdwr |= test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags);
		}
	}
	spin_unlock(&state->owner->so_lock);
	if (!clear_rd && !clear_wr && !clear_rdwr) {
		/* Note: exit _without_ calling nfs4_close_done */
		task->tk_action = NULL;
		return;
	}
	nfs_fattr_init(calldata->res.fattr);
	if (test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0) {
		msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE];
		calldata->arg.open_flags = FMODE_READ;
	} else if (test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0) {
		msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE];
		calldata->arg.open_flags = FMODE_WRITE;
	}
	calldata->timestamp = jiffies;
	rpc_call_setup(task, &msg, 0);
}

static const struct rpc_call_ops nfs4_close_ops = {
	.rpc_call_prepare = nfs4_close_prepare,
	.rpc_call_done = nfs4_close_done,
	.rpc_release = nfs4_free_closedata,
};

/* 
 * 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!
 */
int nfs4_do_close(struct path *path, struct nfs4_state *state, int wait)
{
	struct nfs_server *server = NFS_SERVER(state->inode);
	struct nfs4_closedata *calldata;
	struct nfs4_state_owner *sp = state->owner;
	struct rpc_task *task;
	int status = -ENOMEM;

	calldata = kmalloc(sizeof(*calldata), GFP_KERNEL);
	if (calldata == NULL)
		goto out;
	calldata->inode = state->inode;
	calldata->state = state;
	calldata->arg.fh = NFS_FH(state->inode);
	calldata->arg.stateid = &state->open_stateid;
	/* Serialization for the sequence id */
	calldata->arg.seqid = nfs_alloc_seqid(&state->owner->so_seqid);
	if (calldata->arg.seqid == NULL)
		goto out_free_calldata;
	calldata->arg.bitmask = server->attr_bitmask;
	calldata->res.fattr = &calldata->fattr;
	calldata->res.server = server;
	calldata->path.mnt = mntget(path->mnt);
	calldata->path.dentry = dget(path->dentry);

	task = rpc_run_task(server->client, RPC_TASK_ASYNC, &nfs4_close_ops, calldata);
	if (IS_ERR(task))
		return PTR_ERR(task);
	status = 0;
	if (wait)
		status = rpc_wait_for_completion_task(task);
	rpc_put_task(task);
	return status;
out_free_calldata:
	kfree(calldata);
out:
	nfs4_put_open_state(state);
	nfs4_put_state_owner(sp);
	return status;
}

static int nfs4_intent_set_file(struct nameidata *nd, struct path *path, struct nfs4_state *state)
{
	struct file *filp;
	int ret;

	/* If the open_intent is for execute, we have an extra check to make */
	if (nd->intent.open.flags & FMODE_EXEC) {
		ret = nfs_may_open(state->inode,
				state->owner->so_cred,
				nd->intent.open.flags);
		if (ret < 0)
			goto out_close;
	}
	filp = lookup_instantiate_filp(nd, path->dentry, NULL);
	if (!IS_ERR(filp)) {
		struct nfs_open_context *ctx;
		ctx = nfs_file_open_context(filp);
		ctx->state = state;
		return 0;
	}
	ret = PTR_ERR(filp);
out_close:
	nfs4_close_sync(path, state, nd->intent.open.flags);
	return ret;
}

struct dentry *
nfs4_atomic_open(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	struct dentry *parent;
	struct path path = {
		.mnt = nd->mnt,
		.dentry = dentry,
	};
	struct iattr attr;
	struct rpc_cred *cred;
	struct nfs4_state *state;
	struct dentry *res;

	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_CLIENT(dir)->cl_auth, 0);
	if (IS_ERR(cred))
		return (struct dentry *)cred;
	parent = dentry->d_parent;
	/* Protect against concurrent sillydeletes */
	nfs_block_sillyrename(parent);