nfs3proc.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *  linux/fs/nfs/nfs3proc.c
 *
 *  Client-side NFSv3 procedures stubs.
 *
 *  Copyright (C) 1997, Olaf Kirch
 */

#include <linux/mm.h>
#include <linux/utsname.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/lockd/bind.h>
#include <linux/smp_lock.h>

#define NFSDBG_FACILITY		NFSDBG_PROC

extern struct rpc_procinfo nfs3_procedures[];

/* A wrapper to handle the EJUKEBOX error message */
static int
nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
{
	sigset_t oldset;
	int res;
	rpc_clnt_sigmask(clnt, &oldset);
	do {
		res = rpc_call_sync(clnt, msg, flags);
		if (res != -EJUKEBOX)
			break;
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(NFS_JUKEBOX_RETRY_TIME);
		res = -ERESTARTSYS;
	} while (!signalled());
	rpc_clnt_sigunmask(clnt, &oldset);
	return res;
}

static inline int
nfs3_rpc_call_wrapper(struct rpc_clnt *clnt, u32 proc, void *argp, void *resp, int flags)
{
	struct rpc_message msg = {
		.rpc_proc	= &nfs3_procedures[proc],
		.rpc_argp	= argp,
		.rpc_resp	= resp,
	};
	return nfs3_rpc_wrapper(clnt, &msg, flags);
}

#define rpc_call(clnt, proc, argp, resp, flags) \
		nfs3_rpc_call_wrapper(clnt, proc, argp, resp, flags)
#define rpc_call_sync(clnt, msg, flags) \
		nfs3_rpc_wrapper(clnt, msg, flags)

static int
nfs3_async_handle_jukebox(struct rpc_task *task)
{
	if (task->tk_status != -EJUKEBOX)
		return 0;
	task->tk_status = 0;
	rpc_restart_call(task);
	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
	return 1;
}

/*
 * Bare-bones access to getattr: this is for nfs_read_super.
 */
static int
nfs3_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
		   struct nfs_fsinfo *info)
{
	int	status;

	dprintk("%s: call  fsinfo\n", __FUNCTION__);
	info->fattr->valid = 0;
	status = rpc_call(server->client_sys, NFS3PROC_FSINFO, fhandle, info, 0);
	dprintk("%s: reply fsinfo %d\n", __FUNCTION__, status);
	if (!(info->fattr->valid & NFS_ATTR_FATTR)) {
		status = rpc_call(server->client_sys, NFS3PROC_GETATTR, fhandle, info->fattr, 0);
		dprintk("%s: reply getattr %d\n", __FUNCTION__, status);
	}
	return status;
}

/*
 * One function for each procedure in the NFS protocol.
 */
static int
nfs3_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
		struct nfs_fattr *fattr)
{
	int	status;

	dprintk("NFS call  getattr\n");
	fattr->valid = 0;
	status = rpc_call(server->client, NFS3PROC_GETATTR,
			  fhandle, fattr, 0);
	dprintk("NFS reply getattr\n");
	return status;
}

static int
nfs3_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
			struct iattr *sattr)
{
	struct inode *inode = dentry->d_inode;
	struct nfs3_sattrargs	arg = {
		.fh		= NFS_FH(inode),
		.sattr		= sattr,
	};
	int	status;

	dprintk("NFS call  setattr\n");
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFS3PROC_SETATTR, &arg, fattr, 0);
	dprintk("NFS reply setattr\n");
	return status;
}

static int
nfs3_proc_lookup(struct inode *dir, struct qstr *name,
		 struct nfs_fh *fhandle, struct nfs_fattr *fattr)
{
	struct nfs_fattr	dir_attr;
	struct nfs3_diropargs	arg = {
		.fh		= NFS_FH(dir),
		.name		= name->name,
		.len		= name->len
	};
	struct nfs3_diropres	res = {
		.dir_attr	= &dir_attr,
		.fh		= fhandle,
		.fattr		= fattr
	};
	int			status;

	dprintk("NFS call  lookup %s\n", name->name);
	dir_attr.valid = 0;
	fattr->valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFS3PROC_LOOKUP, &arg, &res, 0);
	if (status >= 0 && !(fattr->valid & NFS_ATTR_FATTR))
		status = rpc_call(NFS_CLIENT(dir), NFS3PROC_GETATTR,
			 fhandle, fattr, 0);
	dprintk("NFS reply lookup: %d\n", status);
	if (status >= 0)
		status = nfs_refresh_inode(dir, &dir_attr);
	return status;
}

static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
{
	struct nfs_fattr	fattr;
	struct nfs3_accessargs	arg = {
		.fh		= NFS_FH(inode),
	};
	struct nfs3_accessres	res = {
		.fattr		= &fattr,
	};
	struct rpc_message msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_ACCESS],
		.rpc_argp	= &arg,
		.rpc_resp	= &res,
		.rpc_cred	= entry->cred
	};
	int mode = entry->mask;
	int status;

	dprintk("NFS call  access\n");
	fattr.valid = 0;

	if (mode & MAY_READ)
		arg.access |= NFS3_ACCESS_READ;
	if (S_ISDIR(inode->i_mode)) {
		if (mode & MAY_WRITE)
			arg.access |= NFS3_ACCESS_MODIFY | NFS3_ACCESS_EXTEND | NFS3_ACCESS_DELETE;
		if (mode & MAY_EXEC)
			arg.access |= NFS3_ACCESS_LOOKUP;
	} else {
		if (mode & MAY_WRITE)
			arg.access |= NFS3_ACCESS_MODIFY | NFS3_ACCESS_EXTEND;
		if (mode & MAY_EXEC)
			arg.access |= NFS3_ACCESS_EXECUTE;
	}
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
	nfs_refresh_inode(inode, &fattr);
	if (status == 0) {
		entry->mask = 0;
		if (res.access & NFS3_ACCESS_READ)
			entry->mask |= MAY_READ;
		if (res.access & (NFS3_ACCESS_MODIFY | NFS3_ACCESS_EXTEND | NFS3_ACCESS_DELETE))
			entry->mask |= MAY_WRITE;
		if (res.access & (NFS3_ACCESS_LOOKUP|NFS3_ACCESS_EXECUTE))
			entry->mask |= MAY_EXEC;
	}
	dprintk("NFS reply access, status = %d\n", status);
	return status;
}

static int nfs3_proc_readlink(struct inode *inode, struct page *page,
		unsigned int pgbase, unsigned int pglen)
{
	struct nfs_fattr	fattr;
	struct nfs3_readlinkargs args = {
		.fh		= NFS_FH(inode),
		.pgbase		= pgbase,
		.pglen		= pglen,
		.pages		= &page
	};
	int			status;

	dprintk("NFS call  readlink\n");
	fattr.valid = 0;
	status = rpc_call(NFS_CLIENT(inode), NFS3PROC_READLINK,
			  &args, &fattr, 0);
	nfs_refresh_inode(inode, &fattr);
	dprintk("NFS reply readlink: %d\n", status);
	return status;
}

static int nfs3_proc_read(struct nfs_read_data *rdata)
{
	int			flags = rdata->flags;
	struct inode *		inode = rdata->inode;
	struct nfs_fattr *	fattr = rdata->res.fattr;
	struct rpc_message	msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_READ],
		.rpc_argp	= &rdata->args,
		.rpc_resp	= &rdata->res,
		.rpc_cred	= rdata->cred,
	};
	int			status;

	dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
			(long long) rdata->args.offset);
	fattr->valid = 0;
	status = rpc_call_sync(NFS_CLIENT(inode), &msg, flags);
	if (status >= 0)
		nfs_refresh_inode(inode, fattr);
	dprintk("NFS reply read: %d\n", status);
	return status;
}

static int nfs3_proc_write(struct nfs_write_data *wdata)
{
	int			rpcflags = wdata->flags;
	struct inode *		inode = wdata->inode;
	struct nfs_fattr *	fattr = wdata->res.fattr;
	struct rpc_message	msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_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(NFS_CLIENT(inode), &msg, rpcflags);
	if (status >= 0)
		nfs_refresh_inode(inode, fattr);
	dprintk("NFS reply write: %d\n", status);
	return status < 0? status : wdata->res.count;
}

static int nfs3_proc_commit(struct nfs_write_data *cdata)
{
	struct inode *		inode = cdata->inode;
	struct nfs_fattr *	fattr = cdata->res.fattr;
	struct rpc_message	msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_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(NFS_CLIENT(inode), &msg, 0);
	if (status >= 0)
		nfs_refresh_inode(inode, fattr);
	dprintk("NFS reply commit: %d\n", status);
	return status;
}

/*
 * Create a regular file.
 * For now, we don't implement O_EXCL.
 */
static struct inode *
nfs3_proc_create(struct inode *dir, struct qstr *name, struct iattr *sattr,
		 int flags)
{
	struct nfs_fh		fhandle;
	struct nfs_fattr	fattr;
	struct nfs_fattr	dir_attr;
	struct nfs3_createargs	arg = {
		.fh		= NFS_FH(dir),
		.name		= name->name,
		.len		= name->len,
		.sattr		= sattr,
	};
	struct nfs3_diropres	res = {
		.dir_attr	= &dir_attr,
		.fh		= &fhandle,
		.fattr		= &fattr
	};
	int			status;

	dprintk("NFS call  create %s\n", name->name);
	arg.createmode = NFS3_CREATE_UNCHECKED;
	if (flags & O_EXCL) {
		arg.createmode  = NFS3_CREATE_EXCLUSIVE;
		arg.verifier[0] = jiffies;
		arg.verifier[1] = current->pid;
	}

again:
	dir_attr.valid = 0;
	fattr.valid = 0;
	status = rpc_call(NFS_CLIENT(dir), NFS3PROC_CREATE, &arg, &res, 0);
	nfs_refresh_inode(dir, &dir_attr);

	/* If the server doesn't support the exclusive creation semantics,
	 * try again with simple 'guarded' mode. */
	if (status == NFSERR_NOTSUPP) {
		switch (arg.createmode) {
			case NFS3_CREATE_EXCLUSIVE:
				arg.createmode = NFS3_CREATE_GUARDED;
				break;

			case NFS3_CREATE_GUARDED:
				arg.createmode = NFS3_CREATE_UNCHECKED;
				break;

			case NFS3_CREATE_UNCHECKED:
				goto exit;
		}
		goto again;
	}

exit:
	dprintk("NFS reply create: %d\n", status);

	if (status != 0)
		goto out;
	if (fhandle.size == 0 || !(fattr.valid & NFS_ATTR_FATTR)) {
		status = nfs3_proc_lookup(dir, name, &fhandle, &fattr);
		if (status != 0)
			goto out;
	}

	/* When we created the file with exclusive semantics, make
	 * sure we set the attributes afterwards. */
	if (arg.createmode == NFS3_CREATE_EXCLUSIVE) {
		struct nfs3_sattrargs	arg = {
			.fh		= &fhandle,
			.sattr		= sattr,
		};
		dprintk("NFS call  setattr (post-create)\n");

		if (!(sattr->ia_valid & ATTR_ATIME_SET))
			sattr->ia_valid |= ATTR_ATIME;
		if (!(sattr->ia_valid & ATTR_MTIME_SET))
			sattr->ia_valid |= ATTR_MTIME;

		/* Note: we could use a guarded setattr here, but I'm
		 * not sure this buys us anything (and I'd have
		 * to revamp the NFSv3 XDR code) */
		fattr.valid = 0;
		status = rpc_call(NFS_CLIENT(dir), NFS3PROC_SETATTR,
						&arg, &fattr, 0);
		dprintk("NFS reply setattr (post-create): %d\n", status);
	}
	if (status == 0) {
		struct inode *inode;
		inode = nfs_fhget(dir->i_sb, &fhandle, &fattr);
		if (inode)
			return inode;
		status = -ENOMEM;
	}
out:
	return ERR_PTR(status);
}

static int
nfs3_proc_remove(struct inode *dir, struct qstr *name)
{
	struct nfs_fattr	dir_attr;
	struct nfs3_diropargs	arg = {
		.fh		= NFS_FH(dir),
		.name		= name->name,
		.len		= name->len
	};
	struct rpc_message	msg = {
		.rpc_proc	= &nfs3_procedures[NFS3PROC_REMOVE],
		.rpc_argp	= &arg,
		.rpc_resp	= &dir_attr,
	};
	int			status;

	dprintk("NFS call  remove %s\n", name->name);
	dir_attr.valid = 0;
	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
	nfs_refresh_inode(dir, &dir_attr);
	dprintk("NFS reply remove: %d\n", status);
	return status;
}

static int
nfs3_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir, struct qstr *name)
{
	struct unlinkxdr {
		struct nfs3_diropargs arg;
		struct nfs_fattr res;
	} *ptr;

	ptr = (struct unlinkxdr *)kmalloc(sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return -ENOMEM;
	ptr->arg.fh = NFS_FH(dir->d_inode);
	ptr->arg.name = name->name;
	ptr->arg.len = name->len;
	ptr->res.valid = 0;
	msg->rpc_proc = &nfs3_procedures[NFS3PROC_REMOVE];
	msg->rpc_argp = &ptr->arg;
	msg->rpc_resp = &ptr->res;
	return 0;