From 5e66d2d92a1c331ed86d943ce3703c654876b20a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 5 Sep 2024 15:09:42 -0400 Subject: [PATCH] nfsd: factor out __fh_verify to allow NULL rqstp to be passed __fh_verify() offers an interface like fh_verify() but doesn't require a struct svc_rqst *, instead it also takes the specific parts as explicit required arguments. So it is safe to call __fh_verify() with a NULL rqstp, but the net, cred, and client args must not be NULL. __fh_verify() does not use SVC_NET(), nor does the functions it calls. Rather than using rqstp->rq_client pass the client and gssclient explicitly to __fh_verify and then to nfsd_set_fh_dentry(). Lastly, it should be noted that the previous commit prepared for 4 associated tracepoints to only be used if rqstp is not NULL (this is a stop-gap that should be properly fixed so localio also benefits from the utility these tracepoints provide when debugging fh_verify issues). Signed-off-by: NeilBrown Co-developed-by: Mike Snitzer Signed-off-by: Mike Snitzer Signed-off-by: Chuck Lever Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker --- fs/nfsd/nfsfh.c | 91 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 60 insertions(+), 31 deletions(-) diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index 60c2395d7af7..a77af71892a3 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -142,7 +142,11 @@ static inline __be32 check_pseudo_root(struct dentry *dentry, * dentry. On success, the results are used to set fh_export and * fh_dentry. */ -static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp) +static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct net *net, + struct svc_cred *cred, + struct auth_domain *client, + struct auth_domain *gssclient, + struct svc_fh *fhp) { struct knfsd_fh *fh = &fhp->fh_handle; struct fid *fid = NULL; @@ -184,8 +188,8 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp) data_left -= len; if (data_left < 0) return error; - exp = rqst_exp_find(&rqstp->rq_chandle, SVC_NET(rqstp), - rqstp->rq_client, rqstp->rq_gssclient, + exp = rqst_exp_find(rqstp ? &rqstp->rq_chandle : NULL, + net, client, gssclient, fh->fh_fsid_type, fh->fh_fsid); fid = (struct fid *)(fh->fh_fsid + len); @@ -220,7 +224,7 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp) put_cred(override_creds(new)); put_cred(new); } else { - error = nfsd_setuser_and_check_port(rqstp, &rqstp->rq_cred, exp); + error = nfsd_setuser_and_check_port(rqstp, cred, exp); if (error) goto out; } @@ -295,42 +299,33 @@ out: } /** - * fh_verify - filehandle lookup and access checking - * @rqstp: pointer to current rpc request + * __fh_verify - filehandle lookup and access checking + * @rqstp: RPC transaction context, or NULL + * @net: net namespace in which to perform the export lookup + * @cred: RPC user credential + * @client: RPC auth domain + * @gssclient: RPC GSS auth domain, or NULL * @fhp: filehandle to be verified * @type: expected type of object pointed to by filehandle * @access: type of access needed to object * - * Look up a dentry from the on-the-wire filehandle, check the client's - * access to the export, and set the current task's credentials. - * - * Regardless of success or failure of fh_verify(), fh_put() should be - * called on @fhp when the caller is finished with the filehandle. - * - * fh_verify() may be called multiple times on a given filehandle, for - * example, when processing an NFSv4 compound. The first call will look - * up a dentry using the on-the-wire filehandle. Subsequent calls will - * skip the lookup and just perform the other checks and possibly change - * the current task's credentials. - * - * @type specifies the type of object expected using one of the S_IF* - * constants defined in include/linux/stat.h. The caller may use zero - * to indicate that it doesn't care, or a negative integer to indicate - * that it expects something not of the given type. - * - * @access is formed from the NFSD_MAY_* constants defined in - * fs/nfsd/vfs.h. + * See fh_verify() for further descriptions of @fhp, @type, and @access. */ -__be32 -fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access) +static __be32 +__fh_verify(struct svc_rqst *rqstp, + struct net *net, struct svc_cred *cred, + struct auth_domain *client, + struct auth_domain *gssclient, + struct svc_fh *fhp, umode_t type, int access) { - struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); + struct nfsd_net *nn = net_generic(net, nfsd_net_id); struct svc_export *exp = NULL; struct dentry *dentry; __be32 error; if (!fhp->fh_dentry) { - error = nfsd_set_fh_dentry(rqstp, fhp); + error = nfsd_set_fh_dentry(rqstp, net, cred, client, + gssclient, fhp); if (error) goto out; } @@ -359,7 +354,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access) if (error) goto out; - error = nfsd_setuser_and_check_port(rqstp, &rqstp->rq_cred, exp); + error = nfsd_setuser_and_check_port(rqstp, cred, exp); if (error) goto out; @@ -389,7 +384,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access) skip_pseudoflavor_check: /* Finally, check access permissions. */ - error = nfsd_permission(&rqstp->rq_cred, exp, dentry, access); + error = nfsd_permission(cred, exp, dentry, access); out: trace_nfsd_fh_verify_err(rqstp, fhp, type, access, error); if (error == nfserr_stale) @@ -397,6 +392,40 @@ out: return error; } +/** + * fh_verify - filehandle lookup and access checking + * @rqstp: pointer to current rpc request + * @fhp: filehandle to be verified + * @type: expected type of object pointed to by filehandle + * @access: type of access needed to object + * + * Look up a dentry from the on-the-wire filehandle, check the client's + * access to the export, and set the current task's credentials. + * + * Regardless of success or failure of fh_verify(), fh_put() should be + * called on @fhp when the caller is finished with the filehandle. + * + * fh_verify() may be called multiple times on a given filehandle, for + * example, when processing an NFSv4 compound. The first call will look + * up a dentry using the on-the-wire filehandle. Subsequent calls will + * skip the lookup and just perform the other checks and possibly change + * the current task's credentials. + * + * @type specifies the type of object expected using one of the S_IF* + * constants defined in include/linux/stat.h. The caller may use zero + * to indicate that it doesn't care, or a negative integer to indicate + * that it expects something not of the given type. + * + * @access is formed from the NFSD_MAY_* constants defined in + * fs/nfsd/vfs.h. + */ +__be32 +fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access) +{ + return __fh_verify(rqstp, SVC_NET(rqstp), &rqstp->rq_cred, + rqstp->rq_client, rqstp->rq_gssclient, + fhp, type, access); +} /* * Compose a file handle for an NFS reply.