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Commit ed748aac authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields
Browse files

NFSD: Cleanup for nfsd4_path() 



The current code is sort of hackish in that it assumes a referral is always
matched to an export. When we add support for junctions that may not be the
case.
We can replace nfsd4_path() with a function that encodes the components
directly from the dentries. Since nfsd4_path is currently the only user of
the 'ex_pathname' field in struct svc_export, this has the added benefit
of allowing us to get rid of that.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent ee626a77

fs/nfsd/export.c

+2 −2
Original line number Diff line number Diff line
@@ -1009,7 +1009,7 @@ rqst_exp_parent(struct svc_rqst *rqstp, struct path *path) 
	return exp;

}



static struct svc_export *find_fsidzero_export(struct svc_rqst *rqstp)

struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)

{

	u32 fsidv[2];
@@ -1029,7 +1029,7 @@ exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp) 
	struct svc_export *exp;

	__be32 rv;



	exp = find_fsidzero_export(rqstp);

	exp = rqst_find_fsidzero_export(rqstp);

	if (IS_ERR(exp))

		return nfserrno(PTR_ERR(exp));

	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);

fs/nfsd/nfs4xdr.c

+78 −28
Original line number Diff line number Diff line
@@ -1696,36 +1696,89 @@ static __be32 nfsd4_encode_fs_location4(struct nfsd4_fs_location *location, 
}



/*

 * Return the path to an export point in the pseudo filesystem namespace

 * Returned string is safe to use as long as the caller holds a reference

 * to @exp.

 * Encode a path in RFC3530 'pathname4' format

 */

static char *nfsd4_path(struct svc_rqst *rqstp, struct svc_export *exp, __be32 *stat)

static __be32 nfsd4_encode_path(const struct path *root,

		const struct path *path, __be32 **pp, int *buflen)

{

	struct svc_fh tmp_fh;

	char *path = NULL, *rootpath;

	size_t rootlen;

	struct path cur = {

		.mnt = path->mnt,

		.dentry = path->dentry,

	};

	__be32 *p = *pp;

	struct dentry **components = NULL;

	unsigned int ncomponents = 0;

	__be32 err = nfserr_jukebox;



	fh_init(&tmp_fh, NFS4_FHSIZE);

	*stat = exp_pseudoroot(rqstp, &tmp_fh);

	if (*stat)

		return NULL;

	rootpath = tmp_fh.fh_export->ex_pathname;

	dprintk("nfsd4_encode_components(");



	path = exp->ex_pathname;

	path_get(&cur);

	/* First walk the path up to the nfsd root, and store the

	 * dentries/path components in an array.

	 */

	for (;;) {

		if (cur.dentry == root->dentry && cur.mnt == root->mnt)

			break;

		if (cur.dentry == cur.mnt->mnt_root) {

			if (follow_up(&cur))

				continue;

			goto out_free;

		}

		if ((ncomponents & 15) == 0) {

			struct dentry **new;

			new = krealloc(components,

					sizeof(*new) * (ncomponents + 16),

					GFP_KERNEL);

			if (!new)

				goto out_free;

			components = new;

		}

		components[ncomponents++] = cur.dentry;

		cur.dentry = dget_parent(cur.dentry);

	}



	*buflen -= 4;

	if (*buflen < 0)

		goto out_free;

	WRITE32(ncomponents);



	while (ncomponents) {

		struct dentry *dentry = components[ncomponents - 1];

		unsigned int len = dentry->d_name.len;



		*buflen -= 4 + (XDR_QUADLEN(len) << 2);

		if (*buflen < 0)

			goto out_free;

		WRITE32(len);

		WRITEMEM(dentry->d_name.name, len);

		dprintk("/%s", dentry->d_name.name);

		dput(dentry);

		ncomponents--;

	}



	rootlen = strlen(rootpath);

	if (strncmp(path, rootpath, rootlen)) {

		dprintk("nfsd: fs_locations failed;"

			"%s is not contained in %s\n", path, rootpath);

		*stat = nfserr_notsupp;

		path = NULL;

		goto out;

	*pp = p;

	err = 0;

out_free:

	dprintk(")\n");

	while (ncomponents)

		dput(components[--ncomponents]);

	kfree(components);

	path_put(&cur);

	return err;

}

	path += rootlen;

out:

	fh_put(&tmp_fh);

	return path;



static __be32 nfsd4_encode_fsloc_fsroot(struct svc_rqst *rqstp,

		const struct path *path, __be32 **pp, int *buflen)

{

	struct svc_export *exp_ps;

	__be32 res;



	exp_ps = rqst_find_fsidzero_export(rqstp);

	if (IS_ERR(exp_ps))

		return nfserrno(PTR_ERR(exp_ps));

	res = nfsd4_encode_path(&exp_ps->ex_path, path, pp, buflen);

	exp_put(exp_ps);

	return res;

}



/*
@@ -1739,11 +1792,8 @@ static __be32 nfsd4_encode_fs_locations(struct svc_rqst *rqstp, 
	int i;

	__be32 *p = *pp;

	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;

	char *root = nfsd4_path(rqstp, exp, &status);



	if (status)

		return status;

	status = nfsd4_encode_components('/', root, &p, buflen);

	status = nfsd4_encode_fsloc_fsroot(rqstp, &exp->ex_path, &p, buflen);

	if (status)

		return status;

	if ((*buflen -= 4) < 0)

include/linux/nfsd/export.h

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ struct svc_export * rqst_exp_get_by_name(struct svc_rqst *, 
					     struct path *);

struct svc_export *	rqst_exp_parent(struct svc_rqst *,

					struct path *);

struct svc_export *	rqst_find_fsidzero_export(struct svc_rqst *);

int			exp_rootfh(struct auth_domain *, 

					char *path, struct knfsd_fh *, int maxsize);

__be32			exp_pseudoroot(struct svc_rqst *, struct svc_fh *);