nfs4proc.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *  fs/nfs/nfs4proc.c
 *
 *  Client-side procedure declarations for NFSv4.
 *
 *  Copyright (c) 2002 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <[e-mail]>
 *  Andy Adamson   <[e-mail]>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#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/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/smp_lock.h>
#include <linux/namei.h>

#include "delegation.h"

#define NFSDBG_FACILITY		NFSDBG_PROC

#define NFS4_POLL_RETRY_MIN	(1*HZ)
#define NFS4_POLL_RETRY_MAX	(15*HZ)

static int nfs4_do_fsinfo(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *);
static int nfs4_async_handle_error(struct rpc_task *, struct nfs_server *);
static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry);
extern u32 *nfs4_decode_dirent(u32 *p, struct nfs_entry *entry, int plus);
extern struct rpc_procinfo nfs4_procedures[];

extern nfs4_stateid zero_stateid;

/* Prevent leaks of NFSv4 errors into userland */
static inline int nfs4_map_errors(int err)
{
	if (err < -1000) {
		printk(KERN_WARNING "%s could not handle NFSv4 error %d\n",
				__FUNCTION__, -err);
		return -EIO;
	}
	return err;
}

/*
 * This is our standard bitmap for GETATTR requests.
 */
const u32 nfs4_fattr_bitmap[2] = {
	FATTR4_WORD0_TYPE
	| FATTR4_WORD0_CHANGE
	| FATTR4_WORD0_SIZE
	| FATTR4_WORD0_FSID
	| FATTR4_WORD0_FILEID,
	FATTR4_WORD1_MODE
	| FATTR4_WORD1_NUMLINKS
	| FATTR4_WORD1_OWNER
	| FATTR4_WORD1_OWNER_GROUP
	| FATTR4_WORD1_RAWDEV
	| FATTR4_WORD1_SPACE_USED
	| FATTR4_WORD1_TIME_ACCESS
	| FATTR4_WORD1_TIME_METADATA
	| FATTR4_WORD1_TIME_MODIFY
};

const u32 nfs4_statfs_bitmap[2] = {
	FATTR4_WORD0_FILES_AVAIL
	| FATTR4_WORD0_FILES_FREE
	| FATTR4_WORD0_FILES_TOTAL,
	FATTR4_WORD1_SPACE_AVAIL
	| FATTR4_WORD1_SPACE_FREE
	| FATTR4_WORD1_SPACE_TOTAL
};

u32 nfs4_pathconf_bitmap[2] = {
	FATTR4_WORD0_MAXLINK
	| FATTR4_WORD0_MAXNAME,
	0
};

const u32 nfs4_fsinfo_bitmap[2] = { FATTR4_WORD0_MAXFILESIZE
			| FATTR4_WORD0_MAXREAD
			| FATTR4_WORD0_MAXWRITE
			| FATTR4_WORD0_LEASE_TIME,
			0
};

static void nfs4_setup_readdir(u64 cookie, u32 *verifier, struct dentry *dentry,
		struct nfs4_readdir_arg *readdir)
{
	u32 *start, *p;

	BUG_ON(readdir->count < 80);
	if (cookie > 2) {
		readdir->cookie = (cookie > 2) ? cookie : 0;
		memcpy(&readdir->verifier, verifier, sizeof(readdir->verifier));
		return;
	}

	readdir->cookie = 0;
	memset(&readdir->verifier, 0, sizeof(readdir->verifier));
	if (cookie == 2)
		return;
	
	/*
	 * NFSv4 servers do not return entries for '.' and '..'
	 * Therefore, we fake these entries here.  We let '.'
	 * have cookie 0 and '..' have cookie 1.  Note that
	 * when talking to the server, we always send cookie 0
	 * instead of 1 or 2.
	 */
	start = p = (u32 *)kmap_atomic(*readdir->pages, KM_USER0);
	
	if (cookie == 0) {
		*p++ = xdr_one;                                  /* next */
		*p++ = xdr_zero;                   /* cookie, first word */
		*p++ = xdr_one;                   /* cookie, second word */
		*p++ = xdr_one;                             /* entry len */
		memcpy(p, ".\0\0\0", 4);                        /* entry */
		p++;
		*p++ = xdr_one;                         /* bitmap length */
		*p++ = htonl(FATTR4_WORD0_FILEID);             /* bitmap */
		*p++ = htonl(8);              /* attribute buffer length */
		p = xdr_encode_hyper(p, dentry->d_inode->i_ino);
	}
	
	*p++ = xdr_one;                                  /* next */
	*p++ = xdr_zero;                   /* cookie, first word */
	*p++ = xdr_two;                   /* cookie, second word */
	*p++ = xdr_two;                             /* entry len */
	memcpy(p, "..\0\0", 4);                         /* entry */
	p++;
	*p++ = xdr_one;                         /* bitmap length */
	*p++ = htonl(FATTR4_WORD0_FILEID);             /* bitmap */
	*p++ = htonl(8);              /* attribute buffer length */
	p = xdr_encode_hyper(p, dentry->d_parent->d_inode->i_ino);

	readdir->pgbase = (char *)p - (char *)start;
	readdir->count -= readdir->pgbase;
	kunmap_atomic(start, KM_USER0);
}

static void
renew_lease(struct nfs_server *server, unsigned long timestamp)
{
	struct nfs4_client *clp = server->nfs4_state;
	spin_lock(&clp->cl_lock);
	if (time_before(clp->cl_last_renewal,timestamp))
		clp->cl_last_renewal = timestamp;
	spin_unlock(&clp->cl_lock);
}

static void update_changeattr(struct inode *inode, struct nfs4_change_info *cinfo)
{
	struct nfs_inode *nfsi = NFS_I(inode);

	if (cinfo->before == nfsi->change_attr && cinfo->atomic)
		nfsi->change_attr = cinfo->after;
}

/*
 * OPEN_RECLAIM:
 * 	reclaim state on the server after a reboot.
 * 	Assumes caller is holding the sp->so_sem
 */
static int _nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
	struct inode *inode = state->inode;
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_delegation *delegation = NFS_I(inode)->delegation;
	struct nfs_openargs o_arg = {
		.fh = NFS_FH(inode),
		.seqid = sp->so_seqid,
		.id = sp->so_id,
		.open_flags = state->state,
		.clientid = server->nfs4_state->cl_clientid,
		.claim = NFS4_OPEN_CLAIM_PREVIOUS,
		.bitmask = server->attr_bitmask,
	};
	struct nfs_openres o_res = {
		.server = server,	/* Grrr */
	};
	struct rpc_message msg = {
		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR],
		.rpc_argp       = &o_arg,
		.rpc_resp	= &o_res,
		.rpc_cred	= sp->so_cred,
	};
	int status;

	if (delegation != NULL) {
		if (!(delegation->flags & NFS_DELEGATION_NEED_RECLAIM)) {
			memcpy(&state->stateid, &delegation->stateid,
					sizeof(state->stateid));
			set_bit(NFS_DELEGATED_STATE, &state->flags);
			return 0;
		}
		o_arg.u.delegation_type = delegation->type;
	}
	status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
	nfs4_increment_seqid(status, sp);
	if (status == 0) {
		memcpy(&state->stateid, &o_res.stateid, sizeof(state->stateid));
		if (o_res.delegation_type != 0) {
			nfs_inode_reclaim_delegation(inode, sp->so_cred, &o_res);
			/* Did the server issue an immediate delegation recall? */
			if (o_res.do_recall)
				nfs_async_inode_return_delegation(inode, &o_res.stateid);
		}
	}
	clear_bit(NFS_DELEGATED_STATE, &state->flags);
	/* Ensure we update the inode attributes */
	NFS_CACHEINV(inode);
	return status;
}

int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
{
	struct nfs_server *server = NFS_SERVER(state->inode);
	struct nfs4_exception exception = { };
	int err;
	do {
		err = _nfs4_open_reclaim(sp, state);
		switch (err) {
			case 0:
			case -NFS4ERR_STALE_CLIENTID:
			case -NFS4ERR_STALE_STATEID:
			case -NFS4ERR_EXPIRED:
				return err;
		}
		err = nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
{
	struct nfs4_state_owner  *sp  = state->owner;
	struct inode *inode = dentry->d_inode;
	struct nfs_server *server = NFS_SERVER(inode);
	struct dentry *parent = dget_parent(dentry);
	struct nfs_openargs arg = {
		.fh = NFS_FH(parent->d_inode),
		.clientid = server->nfs4_state->cl_clientid,
		.name = &dentry->d_name,
		.id = sp->so_id,
		.server = server,
		.bitmask = server->attr_bitmask,
		.claim = NFS4_OPEN_CLAIM_DELEGATE_CUR,
	};
	struct nfs_openres res = {
		.server = server,
	};
	struct 	rpc_message msg = {
		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR],
		.rpc_argp       = &arg,
		.rpc_resp       = &res,
		.rpc_cred	= sp->so_cred,
	};
	int status = 0;

	down(&sp->so_sema);
	if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
		goto out;
	if (state->state == 0)
		goto out;
	arg.seqid = sp->so_seqid;
	arg.open_flags = state->state;
	memcpy(arg.u.delegation.data, state->stateid.data, sizeof(arg.u.delegation.data));
	status = rpc_call_sync(server->client, &msg, RPC_TASK_NOINTR);
	nfs4_increment_seqid(status, sp);
	if (status >= 0) {
		memcpy(state->stateid.data, res.stateid.data,
				sizeof(state->stateid.data));
		clear_bit(NFS_DELEGATED_STATE, &state->flags);
	}
out:
	up(&sp->so_sema);
	dput(parent);
	return status;
}

int nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state)
{
	struct nfs4_exception exception = { };
	struct nfs_server *server = NFS_SERVER(dentry->d_inode);
	int err;
	do {
		err = _nfs4_open_delegation_recall(dentry, state);
		switch (err) {
			case 0:
				return err;
			case -NFS4ERR_STALE_CLIENTID:
			case -NFS4ERR_STALE_STATEID:
			case -NFS4ERR_EXPIRED:
				/* Don't recall a delegation if it was lost */
				nfs4_schedule_state_recovery(server->nfs4_state);
				return err;
		}
		err = nfs4_handle_exception(server, err, &exception);
	} while (exception.retry);
	return err;
}

static int _nfs4_proc_open_confirm(struct rpc_clnt *clnt, const struct nfs_fh *fh, struct nfs4_state_owner *sp, nfs4_stateid *stateid)
{
	struct nfs_open_confirmargs arg = {
		.fh             = fh,
		.seqid          = sp->so_seqid,
		.stateid	= *stateid,
	};
	struct nfs_open_confirmres res;
	struct 	rpc_message msg = {
		.rpc_proc       = &nfs4_procedures[NFSPROC4_CLNT_OPEN_CONFIRM],
		.rpc_argp       = &arg,
		.rpc_resp       = &res,
		.rpc_cred	= sp->so_cred,
	};
	int status;

	status = rpc_call_sync(clnt, &msg, RPC_TASK_NOINTR);
	nfs4_increment_seqid(status, sp);
	if (status >= 0)
		memcpy(stateid, &res.stateid, sizeof(*stateid));
	return status;
}

static int _nfs4_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
{
	struct nfs_access_entry cache;
	int status;

	status = nfs_access_get_cached(inode, cred, &cache);
	if (status == 0)
		goto out;

	/* Be clever: ask server to check for all possible rights */
	cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
	cache.cred = cred;
	cache.jiffies = jiffies;
	status = _nfs4_proc_access(inode, &cache);
	if (status != 0)
		return status;
	nfs_access_add_cache(inode, &cache);
out:
	if ((cache.mask & mask) == mask)
		return 0;
	return -EACCES;
}

/*
 * Returns an nfs4_state + an extra reference to the inode
 */
int _nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred, struct nfs4_state **res)
{
	struct nfs_delegation *delegation;
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs4_client *clp = server->nfs4_state;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs4_state_owner *sp = NULL;
	struct nfs4_state *state = NULL;
	int open_flags = flags & (FMODE_READ|FMODE_WRITE);
	int mask = 0;
	int err;

	/* Protect against reboot recovery - NOTE ORDER! */
	down_read(&clp->cl_sem);
	/* Protect against delegation recall */
	down_read(&nfsi->rwsem);
	delegation = NFS_I(inode)->delegation;
	err = -ENOENT;
	if (delegation == NULL || (delegation->type & open_flags) != open_flags)
		goto out_err;
	err = -ENOMEM;
	if (!(sp = nfs4_get_state_owner(server, cred))) {
		dprintk("%s: nfs4_get_state_owner failed!\n", __FUNCTION__);
		goto out_err;
	}
	down(&sp->so_sema);
	state = nfs4_get_open_state(inode, sp);
	if (state == NULL)
		goto out_err;

	err = -ENOENT;
	if ((state->state & open_flags) == open_flags) {
		spin_lock(&inode->i_lock);
		if (open_flags & FMODE_READ)
			state->nreaders++;
		if (open_flags & FMODE_WRITE)
			state->nwriters++;
		spin_unlock(&inode->i_lock);
		goto out_ok;
	} else if (state->state != 0)
		goto out_err;

	lock_kernel();
	err = _nfs4_do_access(inode, cred, mask);
	unlock_kernel();
	if (err != 0)
		goto out_err;
	spin_lock(&inode->i_lock);
	memcpy(state->stateid.data, delegation->stateid.data,
			sizeof(state->stateid.data));
	state->state |= open_flags;
	if (open_flags & FMODE_READ)
		state->nreaders++;
	if (open_flags & FMODE_WRITE)
		state->nwriters++;
	set_bit(NFS_DELEGATED_STATE, &state->flags);
	spin_unlock(&inode->i_lock);
out_ok:
	up(&sp->so_sema);
	nfs4_put_state_owner(sp);
	up_read(&nfsi->rwsem);
	up_read(&clp->cl_sem);
	igrab(inode);
	*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);
	}
	up_read(&nfsi->rwsem);
	up_read(&clp->cl_sem);
	return err;
}

static struct nfs4_state *nfs4_open_delegated(struct inode *inode, int flags, struct rpc_cred *cred)
{
	struct nfs4_exception exception = { };
	struct nfs4_state *res;
	int err;

	do {
		err = _nfs4_open_delegated(inode, flags, cred, &res);
		if (err == 0)
			break;
		res = ERR_PTR(nfs4_handle_exception(NFS_SERVER(inode),
					err, &exception));
	} while (exception.retry);
	return res;
}

/*
 * Returns an nfs4_state + an referenced inode
 */
static int _nfs4_do_open(struct inode *dir, struct qstr *name, 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 nfs4_client *clp = server->nfs4_state;
	struct inode *inode = NULL;
	int                     status;
	struct nfs_fattr        f_attr = {
		.valid          = 0,