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nfsd: factor out __fh_verify to allow NULL rqstp to be passed

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__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 <neilb@suse.de>
Co-developed-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
This commit is contained in:
NeilBrown 2024-09-05 15:09:42 -04:00 committed by Anna Schumaker
parent 71c61a0077
commit 5e66d2d92a
1 changed files with 60 additions and 31 deletions
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91
fs/nfsd/nfsfh.c
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@ -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.