[net-next-2.6.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/slab.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 <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));

	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 == FSID_MAJOR_MINOR) {
				/* deprecated, convert to type 3 */
				len = key_len(FSID_ENCODE_DEV)/4;
				fh->fh_fsid_type = FSID_ENCODE_DEV;
				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(FSID_DEV, tfh, xdev, xino, 0, NULL);
			exp = exp_find(rqstp->rq_client, FSID_DEV, 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;
	int root_export = (exp->ex_dentry == exp->ex_dentry->d_sb->s_root);

	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 = FSID_DEV;
		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_uuid) {
		if (fhp->fh_maxsize >= 64) {
			if (root_export)
				fsid_type = FSID_UUID16;
			else
				fsid_type = FSID_UUID16_INUM;
		} else {
			if (root_export)
				fsid_type = FSID_UUID8;
			else
				fsid_type = FSID_UUID4_INUM;
		}
	} else if (exp->ex_flags & NFSEXP_FSID)
		fsid_type = FSID_NUM;
	else if (!old_valid_dev(ex_dev))
		/* for newer device numbers, we must use a newer fsid format */
		fsid_type = FSID_ENCODE_DEV;
	else
		fsid_type = FSID_DEV;

	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;
		mk_fsid(fsid_type, datap, ex_dev,
			exp->ex_dentry->d_inode->i_ino,
			exp->ex_fsid, exp->ex_uuid);

		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;
}

enum fsid_source fsid_source(struct svc_fh *fhp)
{
	if (fhp->fh_handle.fh_version != 1)
		return FSIDSOURCE_DEV;
	switch(fhp->fh_handle.fh_fsid_type) {
	case FSID_DEV:
	case FSID_ENCODE_DEV:
	case FSID_MAJOR_MINOR:
		return FSIDSOURCE_DEV;
	case FSID_NUM:
		return FSIDSOURCE_FSID;
	default:
		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
			return FSIDSOURCE_FSID;
		else
			return FSIDSOURCE_UUID;
	}
}
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
1da177e4	12	#include <linux/slab.h>
1da177e4 LT	13	#include <linux/fs.h>
	14	#include <linux/unistd.h>
	15	#include <linux/string.h>
	16	#include <linux/stat.h>
	17	#include <linux/dcache.h>
	18	#include <linux/mount.h>
1da177e4	19
ad06e4bd	20	#include <linux/sunrpc/clnt.h>
1da177e4 LT	21	#include <linux/sunrpc/svc.h>
	22	#include <linux/nfsd/nfsd.h>
	23
	24	#define NFSDDBG_FACILITY NFSDDBG_FH
1da177e4 LT	25
	26
	27	static int nfsd_nr_verified;
	28	static int nfsd_nr_put;
	29
	30	extern struct export_operations export_op_default;
	31
	32	#define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
	33
	34	/*
	35	* our acceptability function.
	36	* if NOSUBTREECHECK, accept anything
	37	* if not, require that we can walk up to exp->ex_dentry
	38	* doing some checks on the 'x' bits
	39	*/
	40	static int nfsd_acceptable(void expv, struct dentry dentry)
	41	{
	42	struct svc_export *exp = expv;
	43	int rv;
	44	struct dentry *tdentry;
	45	struct dentry *parent;
	46
	47	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
	48	return 1;
	49
	50	tdentry = dget(dentry);
	51	while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
	52	/* make sure parents give x permission to user */
	53	int err;
	54	parent = dget_parent(tdentry);
	55	err = permission(parent->d_inode, MAY_EXEC, NULL);
	56	if (err < 0) {
	57	dput(parent);
	58	break;
	59	}
	60	dput(tdentry);
	61	tdentry = parent;
	62	}
	63	if (tdentry != exp->ex_dentry)
	64	dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
	65	rv = (tdentry == exp->ex_dentry);
	66	dput(tdentry);
	67	return rv;
	68	}
	69
	70	/* Type check. The correct error return for type mismatches does not seem to be
	71	* generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
	72	* comment in the NFSv3 spec says this is incorrect (implementation notes for
	73	* the write call).
	74	*/
83b11340	75	static inline __be32
1da177e4 LT	76	nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
	77	{
	78	/* Type can be negative when creating hardlinks - not to a dir */
	79	if (type > 0 && (mode & S_IFMT) != type) {
	80	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	81	return nfserr_symlink;
	82	else if (type == S_IFDIR)
	83	return nfserr_notdir;
	84	else if ((mode & S_IFMT) == S_IFDIR)
	85	return nfserr_isdir;
	86	else
	87	return nfserr_inval;
	88	}
	89	if (type < 0 && (mode & S_IFMT) == -type) {
	90	if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
	91	return nfserr_symlink;
	92	else if (type == -S_IFDIR)
	93	return nfserr_isdir;
	94	else
	95	return nfserr_notdir;
	96	}
	97	return 0;
	98	}
	99
	100	/*
	101	* Perform sanity checks on the dentry in a client's file handle.
	102	*
	103	* Note that the file handle dentry may need to be freed even after
	104	* an error return.
	105	*
	106	* This is only called at the start of an nfsproc call, so fhp points to
	107	* a svc_fh which is all 0 except for the over-the-wire file handle.
	108	*/
83b11340	109	__be32
1da177e4 LT	110	fh_verify(struct svc_rqst rqstp, struct svc_fh fhp, int type, int access)
	111	{
	112	struct knfsd_fh *fh = &fhp->fh_handle;
	113	struct svc_export *exp = NULL;
	114	struct dentry *dentry;
83b11340	115	__be32 error = 0;
1da177e4 LT	116
	117	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
	118
1da177e4 LT	119	if (!fhp->fh_dentry) {
	120	__u32 *datap=NULL;
	121	__u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
	122	int fileid_type;
	123	int data_left = fh->fh_size/4;
	124
	125	error = nfserr_stale;
	126	if (rqstp->rq_client == NULL)
	127	goto out;
	128	if (rqstp->rq_vers > 2)
	129	error = nfserr_badhandle;
	130	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
	131	return nfserr_nofilehandle;
	132
	133	if (fh->fh_version == 1) {
	134	int len;
	135	datap = fh->fh_auth;
	136	if (--data_left<0) goto out;
	137	switch (fh->fh_auth_type) {
	138	case 0: break;
	139	default: goto out;
	140	}
	141	len = key_len(fh->fh_fsid_type) / 4;
	142	if (len == 0) goto out;
af6a4e28	143	if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
1da177e4	144	/* deprecated, convert to type 3 */
af6a4e28 N	145	len = key_len(FSID_ENCODE_DEV)/4;
af6a4e28 N	146	fh->fh_fsid_type = FSID_ENCODE_DEV;
1da177e4 LT	147	fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
	148	fh->fh_fsid[1] = fh->fh_fsid[2];
	149	}
	150	if ((data_left -= len)<0) goto out;
	151	exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
	152	datap += len;
	153	} else {
	154	dev_t xdev;
	155	ino_t xino;
	156	if (fh->fh_size != NFS_FHSIZE)
	157	goto out;
	158	/* assume old filehandle format */
	159	xdev = old_decode_dev(fh->ofh_xdev);
	160	xino = u32_to_ino_t(fh->ofh_xino);
af6a4e28 N	161	mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
	162	exp = exp_find(rqstp->rq_client, FSID_DEV, tfh,
	163	&rqstp->rq_chandle);
1da177e4 LT	164	}
1da177e4 LT	165
e0bb89ef BF	166	if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN
	167	\|\| PTR_ERR(exp) == -ETIMEDOUT)) {
	168	error = nfserrno(PTR_ERR(exp));
1da177e4	169	goto out;
e0bb89ef	170	}
1da177e4 LT	171
	172	error = nfserr_stale;
	173	if (!exp \|\| IS_ERR(exp))
	174	goto out;
	175
	176	/* Check if the request originated from a secure port. */
	177	error = nfserr_perm;
	178	if (!rqstp->rq_secure && EX_SECURE(exp)) {
ad06e4bd	179	char buf[RPC_MAX_ADDRBUFLEN];
1da177e4	180	printk(KERN_WARNING
ad06e4bd CL	181	"nfsd: request from insecure port %s!\n",
ad06e4bd CL	182	svc_print_addr(rqstp, buf, sizeof(buf)));
1da177e4 LT	183	goto out;
	184	}
	185
d1bbf14f N	186	/* Set user creds for this exportpoint */
	187	error = nfserrno(nfsd_setuser(rqstp, exp));
	188	if (error)
	189	goto out;
	190
1da177e4 LT	191	/*
	192	* Look up the dentry using the NFS file handle.
	193	*/
	194	error = nfserr_stale;
	195	if (rqstp->rq_vers > 2)
	196	error = nfserr_badhandle;
	197
	198	if (fh->fh_version != 1) {
	199	tfh[0] = fh->ofh_ino;
	200	tfh[1] = fh->ofh_generation;
	201	tfh[2] = fh->ofh_dirino;
	202	datap = tfh;
	203	data_left = 3;
	204	if (fh->ofh_dirino == 0)
	205	fileid_type = 1;
	206	else
	207	fileid_type = 2;
	208	} else
	209	fileid_type = fh->fh_fileid_type;
982aedfd	210
1da177e4 LT	211	if (fileid_type == 0)
	212	dentry = dget(exp->ex_dentry);
	213	else {
	214	struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
	215	dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
	216	datap, data_left,
	217	fileid_type,
	218	nfsd_acceptable, exp);
	219	}
	220	if (dentry == NULL)
	221	goto out;
	222	if (IS_ERR(dentry)) {
	223	if (PTR_ERR(dentry) != -EINVAL)
	224	error = nfserrno(PTR_ERR(dentry));
	225	goto out;
	226	}
34e9a63b	227
1da177e4 LT	228	if (S_ISDIR(dentry->d_inode->i_mode) &&
	229	(dentry->d_flags & DCACHE_DISCONNECTED)) {
	230	printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
	231	dentry->d_parent->d_name.name, dentry->d_name.name);
	232	}
1da177e4 LT	233
	234	fhp->fh_dentry = dentry;
	235	fhp->fh_export = exp;
	236	nfsd_nr_verified++;
	237	} else {
	238	/* just rechecking permissions
	239	* (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
	240	*/
	241	dprintk("nfsd: fh_verify - just checking\n");
	242	dentry = fhp->fh_dentry;
	243	exp = fhp->fh_export;
d1bbf14f N	244	/* Set user creds for this exportpoint; necessary even
	245	* in the "just checking" case because this may be a
	246	* filehandle that was created by fh_compose, and that
	247	* is about to be used in another nfsv4 compound
	248	* operation */
	249	error = nfserrno(nfsd_setuser(rqstp, exp));
	250	if (error)
	251	goto out;
1da177e4 LT	252	}
	253	cache_get(&exp->h);
	254
7fc90ec9	255
1da177e4 LT	256	error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
	257	if (error)
	258	goto out;
	259
	260	/* Finally, check access permissions. */
	261	error = nfsd_permission(exp, dentry, access);
	262
1da177e4	263	if (error) {
34e9a63b N	264	dprintk("fh_verify: %s/%s permission failure, "
	265	"acc=%x, error=%d\n",
	266	dentry->d_parent->d_name.name,
	267	dentry->d_name.name,
fc2dd2e5	268	access, ntohl(error));
1da177e4	269	}
1da177e4 LT	270	out:
	271	if (exp && !IS_ERR(exp))
	272	exp_put(exp);
	273	if (error == nfserr_stale)
	274	nfsdstats.fh_stale++;
	275	return error;
	276	}
	277
	278
	279	/*
	280	* Compose a file handle for an NFS reply.
	281	*
	282	* Note that when first composed, the dentry may not yet have
	283	* an inode. In this case a call to fh_update should be made
	284	* before the fh goes out on the wire ...
	285	*/
	286	static inline int _fh_update(struct dentry dentry, struct svc_export exp,
	287	__u32 datap, int maxsize)
	288	{
	289	struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
982aedfd	290
1da177e4 LT	291	if (dentry == exp->ex_dentry) {
	292	*maxsize = 0;
	293	return 0;
	294	}
	295
	296	return CALL(nop,encode_fh)(dentry, datap, maxsize,
	297	!(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
	298	}
	299
	300	/*
	301	* for composing old style file handles
	302	*/
	303	static inline void _fh_update_old(struct dentry *dentry,
	304	struct svc_export *exp,
	305	struct knfsd_fh *fh)
	306	{
	307	fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
	308	fh->ofh_generation = dentry->d_inode->i_generation;
	309	if (S_ISDIR(dentry->d_inode->i_mode) \|\|
	310	(exp->ex_flags & NFSEXP_NOSUBTREECHECK))
	311	fh->ofh_dirino = 0;
	312	}
	313
83b11340	314	__be32
982aedfd N	315	fh_compose(struct svc_fh fhp, struct svc_export exp, struct dentry *dentry,
982aedfd N	316	struct svc_fh *ref_fh)
1da177e4 LT	317	{
1da177e4 LT	318	/* ref_fh is a reference file handle.
7e405364 N	319	* if it is non-null and for the same filesystem, then we should compose
7e405364 N	320	* a filehandle which is of the same version, where possible.
1da177e4 LT	321	* Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
	322	* Then create a 32byte filehandle using nfs_fhbase_old
	323	*
	324	*/
	325
982aedfd N	326	u8 version = 1;
982aedfd N	327	u8 fsid_type = 0;
1da177e4 LT	328	struct inode * inode = dentry->d_inode;
	329	struct dentry *parent = dentry->d_parent;
	330	__u32 *datap;
	331	dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
af6a4e28	332	int root_export = (exp->ex_dentry == exp->ex_dentry->d_sb->s_root);
1da177e4 LT	333
	334	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
	335	MAJOR(ex_dev), MINOR(ex_dev),
	336	(long) exp->ex_dentry->d_inode->i_ino,
	337	parent->d_name.name, dentry->d_name.name,
	338	(inode ? inode->i_ino : 0));
	339
982aedfd N	340	/* Choose filehandle version and fsid type based on
	341	* the reference filehandle (if it is in the same export)
	342	* or the export options.
	343	*/
7e405364	344	if (ref_fh && ref_fh->fh_export == exp) {
982aedfd N	345	version = ref_fh->fh_handle.fh_version;
982aedfd N	346	if (version == 0xca)
af6a4e28	347	fsid_type = FSID_DEV;
1da177e4	348	else
982aedfd N	349	fsid_type = ref_fh->fh_handle.fh_fsid_type;
	350	/* We know this version/type works for this export
	351	* so there is no need for further checks.
	352	*/
af6a4e28 N	353	} else if (exp->ex_uuid) {
	354	if (fhp->fh_maxsize >= 64) {
	355	if (root_export)
	356	fsid_type = FSID_UUID16;
	357	else
	358	fsid_type = FSID_UUID16_INUM;
	359	} else {
	360	if (root_export)
	361	fsid_type = FSID_UUID8;
	362	else
	363	fsid_type = FSID_UUID4_INUM;
	364	}
1da177e4	365	} else if (exp->ex_flags & NFSEXP_FSID)
af6a4e28	366	fsid_type = FSID_NUM;
982aedfd	367	else if (!old_valid_dev(ex_dev))
1da177e4	368	/* for newer device numbers, we must use a newer fsid format */
af6a4e28	369	fsid_type = FSID_ENCODE_DEV;
982aedfd	370	else
af6a4e28	371	fsid_type = FSID_DEV;
1da177e4 LT	372
	373	if (ref_fh == fhp)
	374	fh_put(ref_fh);
	375
	376	if (fhp->fh_locked \|\| fhp->fh_dentry) {
	377	printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
982aedfd	378	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	379	}
	380	if (fhp->fh_maxsize < NFS_FHSIZE)
	381	printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
982aedfd N	382	fhp->fh_maxsize,
982aedfd N	383	parent->d_name.name, dentry->d_name.name);
1da177e4 LT	384
	385	fhp->fh_dentry = dget(dentry); /* our internal copy */
	386	fhp->fh_export = exp;
	387	cache_get(&exp->h);
	388
982aedfd	389	if (version == 0xca) {
1da177e4 LT	390	/* old style filehandle please */
	391	memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
	392	fhp->fh_handle.fh_size = NFS_FHSIZE;
	393	fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
	394	fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
	395	fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
982aedfd N	396	fhp->fh_handle.ofh_xino =
982aedfd N	397	ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
1da177e4 LT	398	fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
	399	if (inode)
	400	_fh_update_old(dentry, exp, &fhp->fh_handle);
	401	} else {
	402	int len;
	403	fhp->fh_handle.fh_version = 1;
	404	fhp->fh_handle.fh_auth_type = 0;
	405	datap = fhp->fh_handle.fh_auth+0;
982aedfd	406	fhp->fh_handle.fh_fsid_type = fsid_type;
af6a4e28 N	407	mk_fsid(fsid_type, datap, ex_dev,
	408	exp->ex_dentry->d_inode->i_ino,
	409	exp->ex_fsid, exp->ex_uuid);
	410
982aedfd	411	len = key_len(fsid_type);
1da177e4 LT	412	datap += len/4;
	413	fhp->fh_handle.fh_size = 4 + len;
	414
	415	if (inode) {
	416	int size = (fhp->fh_maxsize-len-4)/4;
	417	fhp->fh_handle.fh_fileid_type =
	418	_fh_update(dentry, exp, datap, &size);
	419	fhp->fh_handle.fh_size += size*4;
	420	}
	421	if (fhp->fh_handle.fh_fileid_type == 255)
	422	return nfserr_opnotsupp;
	423	}
	424
	425	nfsd_nr_verified++;
	426	return 0;
	427	}
	428
	429	/*
	430	* Update file handle information after changing a dentry.
	431	* This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
	432	*/
83b11340	433	__be32
1da177e4 LT	434	fh_update(struct svc_fh *fhp)
	435	{
	436	struct dentry *dentry;
	437	__u32 *datap;
982aedfd	438
1da177e4 LT	439	if (!fhp->fh_dentry)
	440	goto out_bad;
	441
	442	dentry = fhp->fh_dentry;
	443	if (!dentry->d_inode)
	444	goto out_negative;
	445	if (fhp->fh_handle.fh_version != 1) {
	446	_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
	447	} else {
	448	int size;
	449	if (fhp->fh_handle.fh_fileid_type != 0)
4c9608b2	450	goto out;
1da177e4 LT	451	datap = fhp->fh_handle.fh_auth+
	452	fhp->fh_handle.fh_size/4 -1;
	453	size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
	454	fhp->fh_handle.fh_fileid_type =
	455	_fh_update(dentry, fhp->fh_export, datap, &size);
	456	fhp->fh_handle.fh_size += size*4;
	457	if (fhp->fh_handle.fh_fileid_type == 255)
	458	return nfserr_opnotsupp;
	459	}
	460	out:
	461	return 0;
	462
	463	out_bad:
	464	printk(KERN_ERR "fh_update: fh not verified!\n");
	465	goto out;
	466	out_negative:
	467	printk(KERN_ERR "fh_update: %s/%s still negative!\n",
	468	dentry->d_parent->d_name.name, dentry->d_name.name);
	469	goto out;
1da177e4 LT	470	}
	471
	472	/*
	473	* Release a file handle.
	474	*/
	475	void
	476	fh_put(struct svc_fh *fhp)
	477	{
	478	struct dentry * dentry = fhp->fh_dentry;
	479	struct svc_export * exp = fhp->fh_export;
	480	if (dentry) {
	481	fh_unlock(fhp);
	482	fhp->fh_dentry = NULL;
	483	dput(dentry);
	484	#ifdef CONFIG_NFSD_V3
	485	fhp->fh_pre_saved = 0;
	486	fhp->fh_post_saved = 0;
	487	#endif
	488	nfsd_nr_put++;
	489	}
	490	if (exp) {
baab935f	491	cache_put(&exp->h, &svc_export_cache);
1da177e4 LT	492	fhp->fh_export = NULL;
	493	}
	494	return;
	495	}
	496
	497	/*
	498	* Shorthand for dprintk()'s
	499	*/
	500	char * SVCFH_fmt(struct svc_fh *fhp)
	501	{
	502	struct knfsd_fh *fh = &fhp->fh_handle;
	503
	504	static char buf[80];
	505	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
	506	fh->fh_size,
	507	fh->fh_base.fh_pad[0],
	508	fh->fh_base.fh_pad[1],
	509	fh->fh_base.fh_pad[2],
	510	fh->fh_base.fh_pad[3],
	511	fh->fh_base.fh_pad[4],
	512	fh->fh_base.fh_pad[5]);
	513	return buf;
	514	}
af6a4e28 N	515
	516	enum fsid_source fsid_source(struct svc_fh *fhp)
	517	{
	518	if (fhp->fh_handle.fh_version != 1)
	519	return FSIDSOURCE_DEV;
	520	switch(fhp->fh_handle.fh_fsid_type) {
	521	case FSID_DEV:
	522	case FSID_ENCODE_DEV:
	523	case FSID_MAJOR_MINOR:
	524	return FSIDSOURCE_DEV;
	525	case FSID_NUM:
	526	return FSIDSOURCE_FSID;
	527	default:
	528	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
	529	return FSIDSOURCE_FSID;
	530	else
	531	return FSIDSOURCE_UUID;
	532	}
	533	}