[deliverable/linux.git] / fs / nfsd / nfsfh.c

/*
 * linux/fs/nfsd/nfsfh.c
 *
 * NFS server file handle treatment.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
 * ... and again Southern-Winter 2001 to support export_operations
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/dcache.h>
#include <linux/mount.h>
#include <asm/pgtable.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>

#define NFSDDBG_FACILITY		NFSDDBG_FH


static int nfsd_nr_verified;
static int nfsd_nr_put;

extern struct export_operations export_op_default;

#define	CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)

/*
 * our acceptability function.
 * if NOSUBTREECHECK, accept anything
 * if not, require that we can walk up to exp->ex_dentry
 * doing some checks on the 'x' bits
 */
static int nfsd_acceptable(void *expv, struct dentry *dentry)
{
	struct svc_export *exp = expv;
	int rv;
	struct dentry *tdentry;
	struct dentry *parent;

	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
		return 1;

	tdentry = dget(dentry);
	while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
		/* make sure parents give x permission to user */
		int err;
		parent = dget_parent(tdentry);
		err = permission(parent->d_inode, MAY_EXEC, NULL);
		if (err < 0) {
			dput(parent);
			break;
		}
		dput(tdentry);
		tdentry = parent;
	}
	if (tdentry != exp->ex_dentry)
		dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
	rv = (tdentry == exp->ex_dentry);
	dput(tdentry);
	return rv;
}

/* Type check. The correct error return for type mismatches does not seem to be
 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 * comment in the NFSv3 spec says this is incorrect (implementation notes for
 * the write call).
 */
static inline __be32
nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
{
	/* Type can be negative when creating hardlinks - not to a dir */
	if (type > 0 && (mode & S_IFMT) != type) {
		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
			return nfserr_symlink;
		else if (type == S_IFDIR)
			return nfserr_notdir;
		else if ((mode & S_IFMT) == S_IFDIR)
			return nfserr_isdir;
		else
			return nfserr_inval;
	}
	if (type < 0 && (mode & S_IFMT) == -type) {
		if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
			return nfserr_symlink;
		else if (type == -S_IFDIR)
			return nfserr_isdir;
		else
			return nfserr_notdir;
	}
	return 0;
}

/*
 * Perform sanity checks on the dentry in a client's file handle.
 *
 * Note that the file handle dentry may need to be freed even after
 * an error return.
 *
 * This is only called at the start of an nfsproc call, so fhp points to
 * a svc_fh which is all 0 except for the over-the-wire file handle.
 */
__be32
fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
{
	struct knfsd_fh	*fh = &fhp->fh_handle;
	struct svc_export *exp = NULL;
	struct dentry	*dentry;
	__be32		error = 0;

	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));

	/* keep this filehandle for possible reference  when encoding attributes */
	rqstp->rq_reffh = fh;

	if (!fhp->fh_dentry) {
		__u32 *datap=NULL;
		__u32 tfh[3];		/* filehandle fragment for oldstyle filehandles */
		int fileid_type;
		int data_left = fh->fh_size/4;

		error = nfserr_stale;
		if (rqstp->rq_client == NULL)
			goto out;
		if (rqstp->rq_vers > 2)
			error = nfserr_badhandle;
		if (rqstp->rq_vers == 4 && fh->fh_size == 0)
			return nfserr_nofilehandle;

		if (fh->fh_version == 1) {
			int len;
			datap = fh->fh_auth;
			if (--data_left<0) goto out;
			switch (fh->fh_auth_type) {
			case 0: break;
			default: goto out;
			}
			len = key_len(fh->fh_fsid_type) / 4;
			if (len == 0) goto out;
			if  (fh->fh_fsid_type == 2) {
				/* deprecated, convert to type 3 */
				len = 3;
				fh->fh_fsid_type = 3;
				fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
				fh->fh_fsid[1] = fh->fh_fsid[2];
			}
			if ((data_left -= len)<0) goto out;
			exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
			datap += len;
		} else {
			dev_t xdev;
			ino_t xino;
			if (fh->fh_size != NFS_FHSIZE)
				goto out;
			/* assume old filehandle format */
			xdev = old_decode_dev(fh->ofh_xdev);
			xino = u32_to_ino_t(fh->ofh_xino);
			mk_fsid_v0(tfh, xdev, xino);
			exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
		}

		if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN
				|| PTR_ERR(exp) == -ETIMEDOUT)) {
			error = nfserrno(PTR_ERR(exp));
			goto out;
		}

		error = nfserr_stale; 
		if (!exp || IS_ERR(exp))
			goto out;

		/* Check if the request originated from a secure port. */
		error = nfserr_perm;
		if (!rqstp->rq_secure && EX_SECURE(exp)) {
			char buf[RPC_MAX_ADDRBUFLEN];
			printk(KERN_WARNING
			       "nfsd: request from insecure port %s!\n",
			       svc_print_addr(rqstp, buf, sizeof(buf)));
			goto out;
		}

		/* Set user creds for this exportpoint */
		error = nfserrno(nfsd_setuser(rqstp, exp));
		if (error)
			goto out;

		/*
		 * Look up the dentry using the NFS file handle.
		 */
		error = nfserr_stale;
		if (rqstp->rq_vers > 2)
			error = nfserr_badhandle;

		if (fh->fh_version != 1) {
			tfh[0] = fh->ofh_ino;
			tfh[1] = fh->ofh_generation;
			tfh[2] = fh->ofh_dirino;
			datap = tfh;
			data_left = 3;
			if (fh->ofh_dirino == 0)
				fileid_type = 1;
			else
				fileid_type = 2;
		} else
			fileid_type = fh->fh_fileid_type;

		if (fileid_type == 0)
			dentry = dget(exp->ex_dentry);
		else {
			struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
			dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
						     datap, data_left,
						     fileid_type,
						     nfsd_acceptable, exp);
		}
		if (dentry == NULL)
			goto out;
		if (IS_ERR(dentry)) {
			if (PTR_ERR(dentry) != -EINVAL)
				error = nfserrno(PTR_ERR(dentry));
			goto out;
		}

		if (S_ISDIR(dentry->d_inode->i_mode) &&
		    (dentry->d_flags & DCACHE_DISCONNECTED)) {
			printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
			       dentry->d_parent->d_name.name, dentry->d_name.name);
		}

		fhp->fh_dentry = dentry;
		fhp->fh_export = exp;
		nfsd_nr_verified++;
	} else {
		/* just rechecking permissions
		 * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
		 */
		dprintk("nfsd: fh_verify - just checking\n");
		dentry = fhp->fh_dentry;
		exp = fhp->fh_export;
		/* Set user creds for this exportpoint; necessary even
		 * in the "just checking" case because this may be a
		 * filehandle that was created by fh_compose, and that
		 * is about to be used in another nfsv4 compound
		 * operation */
		error = nfserrno(nfsd_setuser(rqstp, exp));
		if (error)
			goto out;
	}
	cache_get(&exp->h);


	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	if (error)
		goto out;

	/* Finally, check access permissions. */
	error = nfsd_permission(exp, dentry, access);

	if (error) {
		dprintk("fh_verify: %s/%s permission failure, "
			"acc=%x, error=%d\n",
			dentry->d_parent->d_name.name,
			dentry->d_name.name,
			access, ntohl(error));
	}
out:
	if (exp && !IS_ERR(exp))
		exp_put(exp);
	if (error == nfserr_stale)
		nfsdstats.fh_stale++;
	return error;
}


/*
 * Compose a file handle for an NFS reply.
 *
 * Note that when first composed, the dentry may not yet have
 * an inode.  In this case a call to fh_update should be made
 * before the fh goes out on the wire ...
 */
static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
			     __u32 *datap, int *maxsize)
{
	struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;

	if (dentry == exp->ex_dentry) {
		*maxsize = 0;
		return 0;
	}

	return CALL(nop,encode_fh)(dentry, datap, maxsize,
			  !(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
}

/*
 * for composing old style file handles
 */
static inline void _fh_update_old(struct dentry *dentry,
				  struct svc_export *exp,
				  struct knfsd_fh *fh)
{
	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	fh->ofh_generation = dentry->d_inode->i_generation;
	if (S_ISDIR(dentry->d_inode->i_mode) ||
	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
		fh->ofh_dirino = 0;
}

__be32
fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
	   struct svc_fh *ref_fh)
{
	/* ref_fh is a reference file handle.
	 * if it is non-null and for the same filesystem, then we should compose
	 * a filehandle which is of the same version, where possible.
	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	 * Then create a 32byte filehandle using nfs_fhbase_old
	 *
	 */

	u8 version = 1;
	u8 fsid_type = 0;
	struct inode * inode = dentry->d_inode;
	struct dentry *parent = dentry->d_parent;
	__u32 *datap;
	dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;

	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
		MAJOR(ex_dev), MINOR(ex_dev),
		(long) exp->ex_dentry->d_inode->i_ino,
		parent->d_name.name, dentry->d_name.name,
		(inode ? inode->i_ino : 0));

	/* Choose filehandle version and fsid type based on
	 * the reference filehandle (if it is in the same export)
	 * or the export options.
	 */
	if (ref_fh && ref_fh->fh_export == exp) {
		version = ref_fh->fh_handle.fh_version;
		if (version == 0xca)
			fsid_type = 0;
		else
			fsid_type = ref_fh->fh_handle.fh_fsid_type;
		/* We know this version/type works for this export
		 * so there is no need for further checks.
		 */
	} else if (exp->ex_flags & NFSEXP_FSID)
		fsid_type = 1;
	else if (!old_valid_dev(ex_dev))
		/* for newer device numbers, we must use a newer fsid format */
		fsid_type = 3;
	else
		fsid_type = 0;

	if (ref_fh == fhp)
		fh_put(ref_fh);

	if (fhp->fh_locked || fhp->fh_dentry) {
		printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
		       parent->d_name.name, dentry->d_name.name);
	}
	if (fhp->fh_maxsize < NFS_FHSIZE)
		printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
		       fhp->fh_maxsize,
		       parent->d_name.name, dentry->d_name.name);

	fhp->fh_dentry = dget(dentry); /* our internal copy */
	fhp->fh_export = exp;
	cache_get(&exp->h);

	if (version == 0xca) {
		/* old style filehandle please */
		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
		fhp->fh_handle.fh_size = NFS_FHSIZE;
		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
		fhp->fh_handle.ofh_xino =
			ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
		if (inode)
			_fh_update_old(dentry, exp, &fhp->fh_handle);
	} else {
		int len;
		fhp->fh_handle.fh_version = 1;
		fhp->fh_handle.fh_auth_type = 0;
		datap = fhp->fh_handle.fh_auth+0;
		fhp->fh_handle.fh_fsid_type = fsid_type;
		switch (fsid_type) {
		case 0:
			/*
			 * fsid_type 0:
			 * 2byte major, 2byte minor, 4byte inode
			 */
			mk_fsid_v0(datap, ex_dev,
				   exp->ex_dentry->d_inode->i_ino);
			break;
		case 1:
			/* fsid_type 1 == 4 bytes filesystem id */
			mk_fsid_v1(datap, exp->ex_fsid);
			break;
		case 2:
			/*
			 * fsid_type 2:
			 * 4byte major, 4byte minor, 4byte inode
			 */
			mk_fsid_v2(datap, ex_dev,
				   exp->ex_dentry->d_inode->i_ino);
			break;
		case 3:
			/*
			 * fsid_type 3:
			 * 4byte devicenumber, 4byte inode
			 */
			mk_fsid_v3(datap, ex_dev,
				   exp->ex_dentry->d_inode->i_ino);
			break;
		}
		len = key_len(fsid_type);
		datap += len/4;
		fhp->fh_handle.fh_size = 4 + len;

		if (inode) {
			int size = (fhp->fh_maxsize-len-4)/4;
			fhp->fh_handle.fh_fileid_type =
				_fh_update(dentry, exp, datap, &size);
			fhp->fh_handle.fh_size += size*4;
		}
		if (fhp->fh_handle.fh_fileid_type == 255)
			return nfserr_opnotsupp;
	}

	nfsd_nr_verified++;
	return 0;
}

/*
 * Update file handle information after changing a dentry.
 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 */
__be32
fh_update(struct svc_fh *fhp)
{
	struct dentry *dentry;
	__u32 *datap;

	if (!fhp->fh_dentry)
		goto out_bad;

	dentry = fhp->fh_dentry;
	if (!dentry->d_inode)
		goto out_negative;
	if (fhp->fh_handle.fh_version != 1) {
		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	} else {
		int size;
		if (fhp->fh_handle.fh_fileid_type != 0)
			goto out;
		datap = fhp->fh_handle.fh_auth+
			fhp->fh_handle.fh_size/4 -1;
		size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
		fhp->fh_handle.fh_fileid_type =
			_fh_update(dentry, fhp->fh_export, datap, &size);
		fhp->fh_handle.fh_size += size*4;
		if (fhp->fh_handle.fh_fileid_type == 255)
			return nfserr_opnotsupp;
	}
out:
	return 0;

out_bad:
	printk(KERN_ERR "fh_update: fh not verified!\n");
	goto out;
out_negative:
	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
		dentry->d_parent->d_name.name, dentry->d_name.name);
	goto out;
}

/*
 * Release a file handle.
 */
void
fh_put(struct svc_fh *fhp)
{
	struct dentry * dentry = fhp->fh_dentry;
	struct svc_export * exp = fhp->fh_export;
	if (dentry) {
		fh_unlock(fhp);
		fhp->fh_dentry = NULL;
		dput(dentry);
#ifdef CONFIG_NFSD_V3
		fhp->fh_pre_saved = 0;
		fhp->fh_post_saved = 0;
#endif
		nfsd_nr_put++;
	}
	if (exp) {
		cache_put(&exp->h, &svc_export_cache);
		fhp->fh_export = NULL;
	}
	return;
}

/*
 * Shorthand for dprintk()'s
 */
char * SVCFH_fmt(struct svc_fh *fhp)
{
	struct knfsd_fh *fh = &fhp->fh_handle;

	static char buf[80];
	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
		fh->fh_size,
		fh->fh_base.fh_pad[0],
		fh->fh_base.fh_pad[1],
		fh->fh_base.fh_pad[2],
		fh->fh_base.fh_pad[3],
		fh->fh_base.fh_pad[4],
		fh->fh_base.fh_pad[5]);
	return buf;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfsd/nfsfh.c
	3	*
	4	* NFS server file handle treatment.
	5	*
	6	* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
	7	* Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
	8	* Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
	9	* ... and again Southern-Winter 2001 to support export_operations
	10	*/
	11
	12	#include <linux/sched.h>
	13	#include <linux/slab.h>
	14	#include <linux/smp_lock.h>
	15	#include <linux/fs.h>
	16	#include <linux/unistd.h>
	17	#include <linux/string.h>
	18	#include <linux/stat.h>
	19	#include <linux/dcache.h>
	20	#include <linux/mount.h>
	21	#include <asm/pgtable.h>
	22
ad06e4bd	23	#include <linux/sunrpc/clnt.h>
1da177e4 LT	24	#include <linux/sunrpc/svc.h>
	25	#include <linux/nfsd/nfsd.h>
	26
	27	#define NFSDDBG_FACILITY NFSDDBG_FH
1da177e4 LT	28
	29
	30	static int nfsd_nr_verified;
	31	static int nfsd_nr_put;
	32
	33	extern struct export_operations export_op_default;
	34
	35	#define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
	36
	37	/*
	38	* our acceptability function.
	39	* if NOSUBTREECHECK, accept anything
	40	* if not, require that we can walk up to exp->ex_dentry
	41	* doing some checks on the 'x' bits
	42	*/
	43	static int nfsd_acceptable(void expv, struct dentry dentry)
	44	{
	45	struct svc_export *exp = expv;
	46	int rv;
	47	struct dentry *tdentry;
	48	struct dentry *parent;
	49
	50	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
	51	return 1;
	52
	53	tdentry = dget(dentry);
	54	while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
	55	/* make sure parents give x permission to user */
	56	int err;
	57	parent = dget_parent(tdentry);
	58	err = permission(parent->d_inode, MAY_EXEC, NULL);
	59	if (err < 0) {
	60	dput(parent);
	61	break;
	62	}
	63	dput(tdentry);
	64	tdentry = parent;
	65	}
	66	if (tdentry != exp->ex_dentry)
	67	dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
	68	rv = (tdentry == exp->ex_dentry);
	69	dput(tdentry);
	70	return rv;
	71	}
	72
	73	/* Type check. The correct error return for type mismatches does not seem to be
	74	* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
	75	* comment in the NFSv3 spec says this is incorrect (implementation notes for
	76	* the write call).
	77	*/
83b11340	78	static inline __be32
1da177e4 LT	79	nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
	80	{
	81	/* Type can be negative when creating hardlinks - not to a dir */
	82	if (type > 0 && (mode & S_IFMT) != type) {
	83	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	84	return nfserr_symlink;
	85	else if (type == S_IFDIR)
	86	return nfserr_notdir;
	87	else if ((mode & S_IFMT) == S_IFDIR)
	88	return nfserr_isdir;
	89	else
	90	return nfserr_inval;
	91	}
	92	if (type < 0 && (mode & S_IFMT) == -type) {
	93	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	94	return nfserr_symlink;
	95	else if (type == -S_IFDIR)
	96	return nfserr_isdir;
	97	else
	98	return nfserr_notdir;
	99	}
	100	return 0;
	101	}
	102
	103	/*
	104	* Perform sanity checks on the dentry in a client's file handle.
	105	*
	106	* Note that the file handle dentry may need to be freed even after
	107	* an error return.
	108	*
	109	* This is only called at the start of an nfsproc call, so fhp points to
	110	* a svc_fh which is all 0 except for the over-the-wire file handle.
	111	*/
83b11340	112	__be32
1da177e4 LT	113	fh_verify(struct svc_rqst rqstp, struct svc_fh fhp, int type, int access)
	114	{
	115	struct knfsd_fh *fh = &fhp->fh_handle;
	116	struct svc_export *exp = NULL;
	117	struct dentry *dentry;
83b11340	118	__be32 error = 0;
1da177e4 LT	119
	120	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
	121
	122	/* keep this filehandle for possible reference when encoding attributes */
	123	rqstp->rq_reffh = fh;
	124
	125	if (!fhp->fh_dentry) {
	126	__u32 *datap=NULL;
	127	__u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
	128	int fileid_type;
	129	int data_left = fh->fh_size/4;
	130
	131	error = nfserr_stale;
	132	if (rqstp->rq_client == NULL)
	133	goto out;
	134	if (rqstp->rq_vers > 2)
	135	error = nfserr_badhandle;
	136	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
	137	return nfserr_nofilehandle;
	138
	139	if (fh->fh_version == 1) {
	140	int len;
	141	datap = fh->fh_auth;
	142	if (--data_left<0) goto out;
	143	switch (fh->fh_auth_type) {
	144	case 0: break;
	145	default: goto out;
	146	}
	147	len = key_len(fh->fh_fsid_type) / 4;
	148	if (len == 0) goto out;
	149	if (fh->fh_fsid_type == 2) {
	150	/* deprecated, convert to type 3 */
	151	len = 3;
	152	fh->fh_fsid_type = 3;
	153	fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
	154	fh->fh_fsid[1] = fh->fh_fsid[2];
	155	}
	156	if ((data_left -= len)<0) goto out;
	157	exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
	158	datap += len;
	159	} else {
	160	dev_t xdev;
	161	ino_t xino;
	162	if (fh->fh_size != NFS_FHSIZE)
	163	goto out;
	164	/* assume old filehandle format */
	165	xdev = old_decode_dev(fh->ofh_xdev);
	166	xino = u32_to_ino_t(fh->ofh_xino);
	167	mk_fsid_v0(tfh, xdev, xino);
	168	exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
	169	}
	170
e0bb89ef BF	171	if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN
	172	\|\| PTR_ERR(exp) == -ETIMEDOUT)) {
	173	error = nfserrno(PTR_ERR(exp));
1da177e4	174	goto out;
e0bb89ef	175	}
1da177e4 LT	176
	177	error = nfserr_stale;
	178	if (!exp \|\| IS_ERR(exp))
	179	goto out;
	180
	181	/* Check if the request originated from a secure port. */
	182	error = nfserr_perm;
	183	if (!rqstp->rq_secure && EX_SECURE(exp)) {
ad06e4bd	184	char buf[RPC_MAX_ADDRBUFLEN];
1da177e4	185	printk(KERN_WARNING
ad06e4bd CL	186	"nfsd: request from insecure port %s!\n",
ad06e4bd CL	187	svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 LT	188	goto out;
	189	}
	190
d1bbf14f N	191	/* Set user creds for this exportpoint */
	192	error = nfserrno(nfsd_setuser(rqstp, exp));
	193	if (error)
	194	goto out;
	195
1da177e4 LT	196	/*
	197	* Look up the dentry using the NFS file handle.
	198	*/
	199	error = nfserr_stale;
	200	if (rqstp->rq_vers > 2)
	201	error = nfserr_badhandle;
	202
	203	if (fh->fh_version != 1) {
	204	tfh[0] = fh->ofh_ino;
	205	tfh[1] = fh->ofh_generation;
	206	tfh[2] = fh->ofh_dirino;
	207	datap = tfh;
	208	data_left = 3;
	209	if (fh->ofh_dirino == 0)
	210	fileid_type = 1;
	211	else
	212	fileid_type = 2;
	213	} else
	214	fileid_type = fh->fh_fileid_type;
982aedfd	215
1da177e4 LT	216	if (fileid_type == 0)
	217	dentry = dget(exp->ex_dentry);
	218	else {
	219	struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
	220	dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
	221	datap, data_left,
	222	fileid_type,
	223	nfsd_acceptable, exp);
	224	}
	225	if (dentry == NULL)
	226	goto out;
	227	if (IS_ERR(dentry)) {
	228	if (PTR_ERR(dentry) != -EINVAL)
	229	error = nfserrno(PTR_ERR(dentry));
	230	goto out;
	231	}
34e9a63b	232
1da177e4 LT	233	if (S_ISDIR(dentry->d_inode->i_mode) &&
	234	(dentry->d_flags & DCACHE_DISCONNECTED)) {
	235	printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
	236	dentry->d_parent->d_name.name, dentry->d_name.name);
	237	}
1da177e4 LT	238
	239	fhp->fh_dentry = dentry;
	240	fhp->fh_export = exp;
	241	nfsd_nr_verified++;
	242	} else {
	243	/* just rechecking permissions
	244	* (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
	245	*/
	246	dprintk("nfsd: fh_verify - just checking\n");
	247	dentry = fhp->fh_dentry;
	248	exp = fhp->fh_export;
d1bbf14f N	249	/* Set user creds for this exportpoint; necessary even
	250	* in the "just checking" case because this may be a
	251	* filehandle that was created by fh_compose, and that
	252	* is about to be used in another nfsv4 compound
	253	* operation */
	254	error = nfserrno(nfsd_setuser(rqstp, exp));
	255	if (error)
	256	goto out;
1da177e4 LT	257	}
	258	cache_get(&exp->h);
	259
7fc90ec9	260
1da177e4 LT	261	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	262	if (error)
	263	goto out;
	264
	265	/* Finally, check access permissions. */
	266	error = nfsd_permission(exp, dentry, access);
	267
1da177e4	268	if (error) {
34e9a63b N	269	dprintk("fh_verify: %s/%s permission failure, "
	270	"acc=%x, error=%d\n",
	271	dentry->d_parent->d_name.name,
	272	dentry->d_name.name,
fc2dd2e5	273	access, ntohl(error));
1da177e4	274	}
1da177e4 LT	275	out:
	276	if (exp && !IS_ERR(exp))
	277	exp_put(exp);
	278	if (error == nfserr_stale)
	279	nfsdstats.fh_stale++;
	280	return error;
	281	}
	282
	283
	284	/*
	285	* Compose a file handle for an NFS reply.
	286	*
	287	* Note that when first composed, the dentry may not yet have
	288	* an inode. In this case a call to fh_update should be made
	289	* before the fh goes out on the wire ...
	290	*/
	291	static inline int _fh_update(struct dentry dentry, struct svc_export exp,
	292	__u32 datap, int maxsize)
	293	{
	294	struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
982aedfd	295
1da177e4 LT	296	if (dentry == exp->ex_dentry) {
	297	*maxsize = 0;
	298	return 0;
	299	}
	300
	301	return CALL(nop,encode_fh)(dentry, datap, maxsize,
	302	!(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
	303	}
	304
	305	/*
	306	* for composing old style file handles
	307	*/
	308	static inline void _fh_update_old(struct dentry *dentry,
	309	struct svc_export *exp,
	310	struct knfsd_fh *fh)
	311	{
	312	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	313	fh->ofh_generation = dentry->d_inode->i_generation;
	314	if (S_ISDIR(dentry->d_inode->i_mode) \|\|
	315	(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
	316	fh->ofh_dirino = 0;
	317	}
	318
83b11340	319	__be32
982aedfd N	320	fh_compose(struct svc_fh fhp, struct svc_export exp, struct dentry *dentry,
982aedfd N	321	struct svc_fh *ref_fh)
1da177e4 LT	322	{
1da177e4 LT	323	/* ref_fh is a reference file handle.
7e405364 N	324	* if it is non-null and for the same filesystem, then we should compose
7e405364 N	325	* a filehandle which is of the same version, where possible.
1da177e4 LT	326	* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	327	* Then create a 32byte filehandle using nfs_fhbase_old
	328	*
	329	*/
	330
982aedfd N	331	u8 version = 1;
982aedfd N	332	u8 fsid_type = 0;
1da177e4 LT	333	struct inode * inode = dentry->d_inode;
	334	struct dentry *parent = dentry->d_parent;
	335	__u32 *datap;
	336	dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
	337
	338	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
	339	MAJOR(ex_dev), MINOR(ex_dev),
	340	(long) exp->ex_dentry->d_inode->i_ino,
	341	parent->d_name.name, dentry->d_name.name,
	342	(inode ? inode->i_ino : 0));
	343
982aedfd N	344	/* Choose filehandle version and fsid type based on
	345	* the reference filehandle (if it is in the same export)
	346	* or the export options.
	347	*/
7e405364	348	if (ref_fh && ref_fh->fh_export == exp) {
982aedfd N	349	version = ref_fh->fh_handle.fh_version;
	350	if (version == 0xca)
	351	fsid_type = 0;
1da177e4	352	else
982aedfd N	353	fsid_type = ref_fh->fh_handle.fh_fsid_type;
	354	/* We know this version/type works for this export
	355	* so there is no need for further checks.
	356	*/
1da177e4	357	} else if (exp->ex_flags & NFSEXP_FSID)
982aedfd N	358	fsid_type = 1;
982aedfd N	359	else if (!old_valid_dev(ex_dev))
1da177e4	360	/* for newer device numbers, we must use a newer fsid format */
982aedfd N	361	fsid_type = 3;
	362	else
	363	fsid_type = 0;
1da177e4 LT	364
	365	if (ref_fh == fhp)
	366	fh_put(ref_fh);
	367
	368	if (fhp->fh_locked \|\| fhp->fh_dentry) {
	369	printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
982aedfd	370	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	371	}
	372	if (fhp->fh_maxsize < NFS_FHSIZE)
	373	printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
982aedfd N	374	fhp->fh_maxsize,
982aedfd N	375	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	376
	377	fhp->fh_dentry = dget(dentry); /* our internal copy */
	378	fhp->fh_export = exp;
	379	cache_get(&exp->h);
	380
982aedfd	381	if (version == 0xca) {
1da177e4 LT	382	/* old style filehandle please */
	383	memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
	384	fhp->fh_handle.fh_size = NFS_FHSIZE;
	385	fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
	386	fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
	387	fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
982aedfd N	388	fhp->fh_handle.ofh_xino =
982aedfd N	389	ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
1da177e4 LT	390	fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
	391	if (inode)
	392	_fh_update_old(dentry, exp, &fhp->fh_handle);
	393	} else {
	394	int len;
	395	fhp->fh_handle.fh_version = 1;
	396	fhp->fh_handle.fh_auth_type = 0;
	397	datap = fhp->fh_handle.fh_auth+0;
982aedfd N	398	fhp->fh_handle.fh_fsid_type = fsid_type;
	399	switch (fsid_type) {
	400	case 0:
	401	/*
	402	* fsid_type 0:
	403	* 2byte major, 2byte minor, 4byte inode
	404	*/
	405	mk_fsid_v0(datap, ex_dev,
	406	exp->ex_dentry->d_inode->i_ino);
	407	break;
	408	case 1:
	409	/* fsid_type 1 == 4 bytes filesystem id */
	410	mk_fsid_v1(datap, exp->ex_fsid);
	411	break;
	412	case 2:
	413	/*
	414	* fsid_type 2:
	415	* 4byte major, 4byte minor, 4byte inode
	416	*/
	417	mk_fsid_v2(datap, ex_dev,
	418	exp->ex_dentry->d_inode->i_ino);
	419	break;
	420	case 3:
	421	/*
	422	* fsid_type 3:
	423	* 4byte devicenumber, 4byte inode
	424	*/
	425	mk_fsid_v3(datap, ex_dev,
	426	exp->ex_dentry->d_inode->i_ino);
	427	break;
1da177e4	428	}
982aedfd	429	len = key_len(fsid_type);
1da177e4 LT	430	datap += len/4;
	431	fhp->fh_handle.fh_size = 4 + len;
	432
	433	if (inode) {
	434	int size = (fhp->fh_maxsize-len-4)/4;
	435	fhp->fh_handle.fh_fileid_type =
	436	_fh_update(dentry, exp, datap, &size);
	437	fhp->fh_handle.fh_size += size*4;
	438	}
	439	if (fhp->fh_handle.fh_fileid_type == 255)
	440	return nfserr_opnotsupp;
	441	}
	442
	443	nfsd_nr_verified++;
	444	return 0;
	445	}
	446
	447	/*
	448	* Update file handle information after changing a dentry.
	449	* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
	450	*/
83b11340	451	__be32
1da177e4 LT	452	fh_update(struct svc_fh *fhp)
	453	{
	454	struct dentry *dentry;
	455	__u32 *datap;
982aedfd	456
1da177e4 LT	457	if (!fhp->fh_dentry)
	458	goto out_bad;
	459
	460	dentry = fhp->fh_dentry;
	461	if (!dentry->d_inode)
	462	goto out_negative;
	463	if (fhp->fh_handle.fh_version != 1) {
	464	_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	465	} else {
	466	int size;
	467	if (fhp->fh_handle.fh_fileid_type != 0)
4c9608b2	468	goto out;
1da177e4 LT	469	datap = fhp->fh_handle.fh_auth+
	470	fhp->fh_handle.fh_size/4 -1;
	471	size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
	472	fhp->fh_handle.fh_fileid_type =
	473	_fh_update(dentry, fhp->fh_export, datap, &size);
	474	fhp->fh_handle.fh_size += size*4;
	475	if (fhp->fh_handle.fh_fileid_type == 255)
	476	return nfserr_opnotsupp;
	477	}
	478	out:
	479	return 0;
	480
	481	out_bad:
	482	printk(KERN_ERR "fh_update: fh not verified!\n");
	483	goto out;
	484	out_negative:
	485	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
	486	dentry->d_parent->d_name.name, dentry->d_name.name);
	487	goto out;
1da177e4 LT	488	}
	489
	490	/*
	491	* Release a file handle.
	492	*/
	493	void
	494	fh_put(struct svc_fh *fhp)
	495	{
	496	struct dentry * dentry = fhp->fh_dentry;
	497	struct svc_export * exp = fhp->fh_export;
	498	if (dentry) {
	499	fh_unlock(fhp);
	500	fhp->fh_dentry = NULL;
	501	dput(dentry);
	502	#ifdef CONFIG_NFSD_V3
	503	fhp->fh_pre_saved = 0;
	504	fhp->fh_post_saved = 0;
	505	#endif
	506	nfsd_nr_put++;
	507	}
	508	if (exp) {
baab935f	509	cache_put(&exp->h, &svc_export_cache);
1da177e4 LT	510	fhp->fh_export = NULL;
	511	}
	512	return;
	513	}
	514
	515	/*
	516	* Shorthand for dprintk()'s
	517	*/
	518	char * SVCFH_fmt(struct svc_fh *fhp)
	519	{
	520	struct knfsd_fh *fh = &fhp->fh_handle;
	521
	522	static char buf[80];
	523	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
	524	fh->fh_size,
	525	fh->fh_base.fh_pad[0],
	526	fh->fh_base.fh_pad[1],
	527	fh->fh_base.fh_pad[2],
	528	fh->fh_base.fh_pad[3],
	529	fh->fh_base.fh_pad[4],
	530	fh->fh_base.fh_pad[5]);
	531	return buf;
	532	}