Commit 2d3bb252 authored by J. Bruce Fields's avatar J. Bruce Fields Committed by Linus Torvalds
Browse files

knfsd: nfsd: make all exp_finding functions return -errno's on err 



Currently exp_find(), exp_get_by_name(), and friends, return an export on
success, and on failure return:

	errors -EAGAIN (drop this request pending an upcall) or
		-ETIMEDOUT (an upcall has timed out), or
	return NULL, which can mean either that there was a memory allocation
		failure, or that an export was not found, or that a passed-in
		export lacks an auth_domain.

Many callers seem to assume that NULL means that an export was not found,
which may lead to bugs in the case of a memory allocation failure.

Modify these functions to distinguish between the two NULL cases by returning
either -ENOENT or -ENOMEM.  They now never return NULL.  We get to simplify
some code in the process.

We return -ENOENT in the case of a missing auth_domain.  This case should
probably be removed (or converted to a bug) after confirming that it can never
happen.

Signed-off-by: default avatar"J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 47f9940c

fs/nfsd/export.c

+23 −35
Original line number Diff line number Diff line
@@ -739,16 +739,18 @@ exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp) 
	int err;

	

	if (!clp)

		return NULL;

		return ERR_PTR(-ENOENT);



	key.ek_client = clp;

	key.ek_fsidtype = fsid_type;

	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));



	ek = svc_expkey_lookup(&key);

	if (ek != NULL)

		if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))

			ek = ERR_PTR(err);

	if (ek == NULL)

		return ERR_PTR(-ENOMEM);

	err = cache_check(&svc_expkey_cache, &ek->h, reqp);

	if (err)

		return ERR_PTR(err);

	return ek;

}
@@ -809,30 +811,21 @@ exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry, 
		struct cache_req *reqp)

{

	struct svc_export *exp, key;

	int err;

	

	if (!clp)

		return NULL;

		return ERR_PTR(-ENOENT);



	key.ex_client = clp;

	key.ex_mnt = mnt;

	key.ex_dentry = dentry;



	exp = svc_export_lookup(&key);

	if (exp != NULL)  {

		int err;



	if (exp == NULL)

		return ERR_PTR(-ENOMEM);

	err = cache_check(&svc_export_cache, &exp->h, reqp);

		switch (err) {

		case 0: break;

		case -EAGAIN:

		case -ETIMEDOUT:

			exp = ERR_PTR(err);

			break;

		default:

			exp = NULL;

		}

	}



	if (err)

		return ERR_PTR(err);

	return exp;

}
@@ -848,7 +841,7 @@ exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry, 
	dget(dentry);

	exp = exp_get_by_name(clp, mnt, dentry, reqp);



	while (exp == NULL && !IS_ROOT(dentry)) {

	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(dentry)) {

		struct dentry *parent;



		parent = dget_parent(dentry);
@@ -901,7 +894,7 @@ static void exp_fsid_unhash(struct svc_export *exp) 
		return;



	ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);

	if (ek && !IS_ERR(ek)) {

	if (!IS_ERR(ek)) {

		ek->h.expiry_time = get_seconds()-1;

		cache_put(&ek->h, &svc_expkey_cache);

	}
@@ -939,7 +932,7 @@ static void exp_unhash(struct svc_export *exp) 
	struct inode *inode = exp->ex_dentry->d_inode;



	ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);

	if (ek && !IS_ERR(ek)) {

	if (!IS_ERR(ek)) {

		ek->h.expiry_time = get_seconds()-1;

		cache_put(&ek->h, &svc_expkey_cache);

	}
@@ -990,13 +983,12 @@ exp_export(struct nfsctl_export *nxp) 


	/* must make sure there won't be an ex_fsid clash */

	if ((nxp->ex_flags & NFSEXP_FSID) &&

	    (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&

	    !IS_ERR(fsid_key) &&

	    (!IS_ERR(fsid_key = exp_get_fsid_key(clp, nxp->ex_dev))) &&

	    fsid_key->ek_mnt &&

	    (fsid_key->ek_mnt != nd.mnt || fsid_key->ek_dentry != nd.dentry) )

		goto finish;



	if (exp) {

	if (!IS_ERR(exp)) {

		/* just a flags/id/fsid update */



		exp_fsid_unhash(exp);
@@ -1105,7 +1097,7 @@ exp_unexport(struct nfsctl_export *nxp) 
	err = -EINVAL;

	exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);

	path_release(&nd);

	if (!exp)

	if (IS_ERR(exp))

		goto out_domain;



	exp_do_unexport(exp);
@@ -1150,10 +1142,6 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize) 
		err = PTR_ERR(exp);

		goto out;

	}

	if (!exp) {

		dprintk("nfsd: exp_rootfh export not found.\n");

		goto out;

	}



	/*

	 * fh must be initialized before calling fh_compose
@@ -1177,13 +1165,13 @@ exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv, 
{

	struct svc_export *exp;

	struct svc_expkey *ek = exp_find_key(clp, fsid_type, fsidv, reqp);

	if (!ek || IS_ERR(ek))

	if (IS_ERR(ek))

		return ERR_PTR(PTR_ERR(ek));



	exp = exp_get_by_name(clp, ek->ek_mnt, ek->ek_dentry, reqp);

	cache_put(&ek->h, &svc_expkey_cache);



	if (!exp || IS_ERR(exp))

	if (IS_ERR(exp))

		return ERR_PTR(PTR_ERR(exp));

	return exp;

}
@@ -1205,10 +1193,10 @@ exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp, 
	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);



	exp = exp_find(clp, FSID_NUM, fsidv, creq);

	if (PTR_ERR(exp) == -ENOENT)

		return nfserr_perm;

	if (IS_ERR(exp))

		return nfserrno(PTR_ERR(exp));

	if (exp == NULL)

		return nfserr_perm;

	rv = fh_compose(fhp, exp, exp->ex_dentry, NULL);

	exp_put(exp);

	return rv;

fs/nfsd/nfsfh.c

+5 −6
Original line number Diff line number Diff line
@@ -160,15 +160,14 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) 
				       &rqstp->rq_chandle);

		}



		if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN

				|| PTR_ERR(exp) == -ETIMEDOUT)) {

			error = nfserrno(PTR_ERR(exp));

		error = nfserr_stale;

		if (PTR_ERR(exp) == -ENOENT)

			goto out;

		}



		error = nfserr_stale; 

		if (!exp || IS_ERR(exp))

		if (IS_ERR(exp)) {

			error = nfserrno(PTR_ERR(exp));

			goto out;

		}



		/* Check if the request originated from a secure port. */

		error = nfserr_perm;

fs/nfsd/vfs.c

+4 −5
Original line number Diff line number Diff line
@@ -192,15 +192,14 @@ nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 


			exp2 = exp_parent(exp->ex_client, mnt, dentry,

					  &rqstp->rq_chandle);

			if (IS_ERR(exp2)) {

			if (PTR_ERR(exp2) == -ENOENT) {

				dput(dentry);

				dentry = dget(dparent);

			} else if (IS_ERR(exp2)) {

				host_err = PTR_ERR(exp2);

				dput(dentry);

				mntput(mnt);

				goto out_nfserr;

			}

			if (!exp2) {

				dput(dentry);

				dentry = dget(dparent);

			} else {

				exp_put(exp);

				exp = exp2;

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