2013-03-05 22:17:23

by J. Bruce Fields

[permalink] [raw]
Subject: [PATCH 1/2] nfsd4: remove BUG_ON

From: "J. Bruce Fields" <[email protected]>

This BUG_ON just crashes the thread a little earlier than it would
otherwise--it doesn't seem useful.

Signed-off-by: J. Bruce Fields <[email protected]>
---
fs/nfsd/nfs4proc.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index ae73175..c7e4e8c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1282,12 +1282,9 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
if (op->status)
goto encode_op;

- if (opdesc->op_func) {
- if (opdesc->op_get_currentstateid)
- opdesc->op_get_currentstateid(cstate, &op->u);
- op->status = opdesc->op_func(rqstp, cstate, &op->u);
- } else
- BUG_ON(op->status == nfs_ok);
+ if (opdesc->op_get_currentstateid)
+ opdesc->op_get_currentstateid(cstate, &op->u);
+ op->status = opdesc->op_func(rqstp, cstate, &op->u);

if (!op->status) {
if (opdesc->op_set_currentstateid)
--
1.7.9.5



2013-03-05 22:17:59

by J. Bruce Fields

[permalink] [raw]
Subject: [PATCH 2/2] nfsd4: handle seqid-mutating open errors from xdr decoding

From: "J. Bruce Fields" <[email protected]>

If a client sets an owner (or group_owner or acl) attribute on open for
create, and the mapping of that owner to an id fails, then we return
BAD_OWNER. But BAD_OWNER is a seqid-mutating error, so we can't
shortcut the open processing that case: we have to at least look up the
owner so we can find the seqid to bump.

Signed-off-by: J. Bruce Fields <[email protected]>
---
fs/nfsd/nfs4proc.c | 27 ++++++++++++++++++++++++++-
fs/nfsd/nfs4xdr.c | 1 +
fs/nfsd/xdr4.h | 1 +
3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index c7e4e8c..42c498c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -351,6 +351,10 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
}
if (status)
goto out;
+ if (open->op_xdr_error) {
+ status = open->op_xdr_error;
+ goto out;
+ }

status = nfsd4_check_open_attributes(rqstp, cstate, open);
if (status)
@@ -417,6 +421,24 @@ out:
}

/*
+ * OPEN is the only seqid-mutating operation whose decoding can fail
+ * with a seqid-mutating error (specifically, decoding of user names in
+ * the attributes). Therefore we have to do some processing to look up
+ * the stateowner so that we can bump the seqid.
+ */
+static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
+{
+ struct nfsd4_open *open = (struct nfsd4_open *)&op->u;
+
+ if (!seqid_mutating_err(ntohl(op->status)))
+ return op->status;
+ if (nfsd4_has_session(cstate))
+ return op->status;
+ open->op_xdr_error = op->status;
+ return nfsd4_open(rqstp, cstate, open);
+}
+
+/*
* filehandle-manipulating ops.
*/
static __be32
@@ -1244,8 +1266,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
* for example, if there is a miscellaneous XDR error
* it will be set to nfserr_bad_xdr.
*/
- if (op->status)
+ if (op->status) {
+ if (op->opnum == OP_OPEN)
+ op->status = nfsd4_open_omfg(rqstp, cstate, op);
goto encode_op;
+ }

/* We must be able to encode a successful response to
* this operation, with enough room left over to encode a
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 0116886..a82df26 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -804,6 +804,7 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
open->op_iattr.ia_valid = 0;
open->op_openowner = NULL;

+ open->op_xdr_error = 0;
/* seqid, share_access, share_deny, clientid, ownerlen */
READ_BUF(4);
READ32(open->op_seqid);
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 546f898..be0a79d 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -237,6 +237,7 @@ struct nfsd4_open {
u32 op_share_deny; /* request */
u32 op_deleg_want; /* request */
stateid_t op_stateid; /* response */
+ __be32 op_xdr_error; /* see nfsd4_open_omfg() */
u32 op_recall; /* recall */
struct nfsd4_change_info op_cinfo; /* response */
u32 op_rflags; /* response */
--
1.7.9.5


2013-03-05 22:22:50

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [PATCH 2/2] nfsd4: handle seqid-mutating open errors from xdr decoding

On Tue, Mar 05, 2013 at 05:17:59PM -0500, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <[email protected]>
>
> If a client sets an owner (or group_owner or acl) attribute on open for
> create, and the mapping of that owner to an id fails, then we return
> BAD_OWNER. But BAD_OWNER is a seqid-mutating error, so we can't
> shortcut the open processing that case: we have to at least look up the
> owner so we can find the seqid to bump.

This seems like an awful hack.

Better might be to move idmapping out of xdr decoding, but that's a
bigger change and I wonder if it would break anything else.

--b.

>
> Signed-off-by: J. Bruce Fields <[email protected]>
> ---
> fs/nfsd/nfs4proc.c | 27 ++++++++++++++++++++++++++-
> fs/nfsd/nfs4xdr.c | 1 +
> fs/nfsd/xdr4.h | 1 +
> 3 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index c7e4e8c..42c498c 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -351,6 +351,10 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> }
> if (status)
> goto out;
> + if (open->op_xdr_error) {
> + status = open->op_xdr_error;
> + goto out;
> + }
>
> status = nfsd4_check_open_attributes(rqstp, cstate, open);
> if (status)
> @@ -417,6 +421,24 @@ out:
> }
>
> /*
> + * OPEN is the only seqid-mutating operation whose decoding can fail
> + * with a seqid-mutating error (specifically, decoding of user names in
> + * the attributes). Therefore we have to do some processing to look up
> + * the stateowner so that we can bump the seqid.
> + */
> +static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
> +{
> + struct nfsd4_open *open = (struct nfsd4_open *)&op->u;
> +
> + if (!seqid_mutating_err(ntohl(op->status)))
> + return op->status;
> + if (nfsd4_has_session(cstate))
> + return op->status;
> + open->op_xdr_error = op->status;
> + return nfsd4_open(rqstp, cstate, open);
> +}
> +
> +/*
> * filehandle-manipulating ops.
> */
> static __be32
> @@ -1244,8 +1266,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
> * for example, if there is a miscellaneous XDR error
> * it will be set to nfserr_bad_xdr.
> */
> - if (op->status)
> + if (op->status) {
> + if (op->opnum == OP_OPEN)
> + op->status = nfsd4_open_omfg(rqstp, cstate, op);
> goto encode_op;
> + }
>
> /* We must be able to encode a successful response to
> * this operation, with enough room left over to encode a
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index 0116886..a82df26 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -804,6 +804,7 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
> open->op_iattr.ia_valid = 0;
> open->op_openowner = NULL;
>
> + open->op_xdr_error = 0;
> /* seqid, share_access, share_deny, clientid, ownerlen */
> READ_BUF(4);
> READ32(open->op_seqid);
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 546f898..be0a79d 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -237,6 +237,7 @@ struct nfsd4_open {
> u32 op_share_deny; /* request */
> u32 op_deleg_want; /* request */
> stateid_t op_stateid; /* response */
> + __be32 op_xdr_error; /* see nfsd4_open_omfg() */
> u32 op_recall; /* recall */
> struct nfsd4_change_info op_cinfo; /* response */
> u32 op_rflags; /* response */
> --
> 1.7.9.5
>