[PATCH 005 of 5] knfsd: Allow lockd to drop replys as appropriate.

From: NeilBrown
Date: Mon Oct 16 2006 - 19:31:18 EST

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It is possible for the ->fopen callback from lockd into nfsd to find
that an answer cannot be given straight away (an upcall is needed) and
so the request has to be 'dropped', to be retried later.
That error status is not currently propagated back.

So:
Change nlm_fopen to return nlm error codes (rather than a private
protocol) and define a new nlm_drop_reply code.
Cause nlm_drop_reply to cause the rpc request to get rpc_drop_reply
when this error comes back.
Cause svc_process to drop a request which returns a status of
rpc_drop_reply.

Cc: Marc Eshel <eshel@xxxxxxxxxxxxxxx>

Signed-off-by: Neil Brown <neilb@xxxxxxx>

### Diffstat output
./fs/lockd/svc4proc.c | 12 ++++++------
./fs/lockd/svcproc.c | 16 +++++++++-------
./fs/lockd/svcsubs.c | 6 ------
./fs/nfsd/lockd.c | 14 ++++++++------
./include/linux/lockd/bind.h | 5 +++++
./include/linux/lockd/xdr.h | 2 ++
./include/linux/sunrpc/msg_prot.h | 4 +++-
./include/linux/sunrpc/xdr.h | 1 +
./net/sunrpc/svc.c | 5 +++++
9 files changed, 39 insertions(+), 26 deletions(-)

diff .prev/fs/lockd/svc4proc.c ./fs/lockd/svc4proc.c
--- .prev/fs/lockd/svc4proc.c 2006-10-17 09:10:54.000000000 +1000
+++ ./fs/lockd/svc4proc.c 2006-10-17 09:10:55.000000000 +1000
@@ -96,7 +96,7 @@ nlm4svc_proc_test(struct svc_rqst *rqstp

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now check for conflicting locks */
resp->status = nlmsvc_testlock(file, &argp->lock, &resp->lock);
@@ -126,7 +126,7 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

#if 0
/* If supplied state doesn't match current state, we assume it's
@@ -169,7 +169,7 @@ nlm4svc_proc_cancel(struct svc_rqst *rqs

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Try to cancel request. */
resp->status = nlmsvc_cancel_blocked(file, &argp->lock);
@@ -202,7 +202,7 @@ nlm4svc_proc_unlock(struct svc_rqst *rqs

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to remove the lock */
resp->status = nlmsvc_unlock(file, &argp->lock);
@@ -339,7 +339,7 @@ nlm4svc_proc_share(struct svc_rqst *rqst

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to create the share */
resp->status = nlmsvc_share_file(host, file, argp);
@@ -372,7 +372,7 @@ nlm4svc_proc_unshare(struct svc_rqst *rq

/* Obtain client and file */
if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to lock the file */
resp->status = nlmsvc_unshare_file(host, file, argp);

diff .prev/fs/lockd/svcproc.c ./fs/lockd/svcproc.c
--- .prev/fs/lockd/svcproc.c 2006-10-17 09:10:54.000000000 +1000
+++ ./fs/lockd/svcproc.c 2006-10-17 09:10:55.000000000 +1000
@@ -59,7 +59,7 @@ nlmsvc_retrieve_args(struct svc_rqst *rq
struct nlm_host *host = NULL;
struct nlm_file *file = NULL;
struct nlm_lock *lock = &argp->lock;
- u32 error;
+ u32 error = 0;

/* nfsd callbacks must have been installed for this procedure */
if (!nlmsvc_ops)
@@ -88,6 +88,8 @@ nlmsvc_retrieve_args(struct svc_rqst *rq
no_locks:
if (host)
nlm_release_host(host);
+ if (error)
+ return error;
return nlm_lck_denied_nolocks;
}

@@ -122,7 +124,7 @@ nlmsvc_proc_test(struct svc_rqst *rqstp,

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now check for conflicting locks */
resp->status = cast_status(nlmsvc_testlock(file, &argp->lock, &resp->lock));
@@ -153,7 +155,7 @@ nlmsvc_proc_lock(struct svc_rqst *rqstp,

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

#if 0
/* If supplied state doesn't match current state, we assume it's
@@ -196,7 +198,7 @@ nlmsvc_proc_cancel(struct svc_rqst *rqst

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Try to cancel request. */
resp->status = cast_status(nlmsvc_cancel_blocked(file, &argp->lock));
@@ -229,7 +231,7 @@ nlmsvc_proc_unlock(struct svc_rqst *rqst

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to remove the lock */
resp->status = cast_status(nlmsvc_unlock(file, &argp->lock));
@@ -368,7 +370,7 @@ nlmsvc_proc_share(struct svc_rqst *rqstp

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to create the share */
resp->status = cast_status(nlmsvc_share_file(host, file, argp));
@@ -401,7 +403,7 @@ nlmsvc_proc_unshare(struct svc_rqst *rqs

/* Obtain client and file */
if ((resp->status = nlmsvc_retrieve_args(rqstp, argp, &host, &file)))
- return rpc_success;
+ return resp->status == nlm_drop_reply ? rpc_drop_reply :rpc_success;

/* Now try to unshare the file */
resp->status = cast_status(nlmsvc_unshare_file(host, file, argp));

diff .prev/fs/lockd/svcsubs.c ./fs/lockd/svcsubs.c
--- .prev/fs/lockd/svcsubs.c 2006-10-17 09:10:40.000000000 +1000
+++ ./fs/lockd/svcsubs.c 2006-10-17 09:13:54.000000000 +1000
@@ -135,12 +135,6 @@ out_unlock:

out_free:
kfree(file);
-#ifdef CONFIG_LOCKD_V4
- if (nfserr == 1)
- nfserr = nlm4_stale_fh;
- else
-#endif
- nfserr = nlm_lck_denied;
goto out_unlock;
}

diff .prev/fs/nfsd/lockd.c ./fs/nfsd/lockd.c
--- .prev/fs/nfsd/lockd.c 2006-10-17 09:10:54.000000000 +1000
+++ ./fs/nfsd/lockd.c 2006-10-17 09:19:18.000000000 +1000
@@ -39,18 +39,20 @@ nlm_fopen(struct svc_rqst *rqstp, struct
fh_put(&fh);
rqstp->rq_client = NULL;
exp_readunlock();
- /* nlm and nfsd don't share error codes.
- * we invent: 0 = no error
- * 1 = stale file handle
- * 2 = other error
+ /* We return nlm error codes as nlm doesn't know
+ * about nfsd, but nfsd does know about nlm..
*/
switch (nfserr) {
case nfs_ok:
return 0;
+ case nfserr_dropit:
+ return nlm_drop_reply;
+#ifdef CONFIG_LOCKD_V4
case nfserr_stale:
- return 1;
+ return nlm4_stale_fh;
+#endif
default:
- return 2;
+ return nlm_lck_denied;
}
}

diff .prev/include/linux/lockd/bind.h ./include/linux/lockd/bind.h
--- .prev/include/linux/lockd/bind.h 2006-10-17 09:20:09.000000000 +1000
+++ ./include/linux/lockd/bind.h 2006-10-17 09:22:26.000000000 +1000
@@ -10,6 +10,11 @@
#define LINUX_LOCKD_BIND_H

#include <linux/lockd/nlm.h>
+/* need xdr-encoded error codes too, so... */
+#include <linux/lockd/xdr.h>
+#ifdef CONFIG_LOCKD_V4
+#include <linux/lockd/xdr4.h>
+#endif

/* Dummy declarations */
struct svc_rqst;

diff .prev/include/linux/lockd/xdr.h ./include/linux/lockd/xdr.h
--- .prev/include/linux/lockd/xdr.h 2006-10-17 09:10:54.000000000 +1000
+++ ./include/linux/lockd/xdr.h 2006-10-17 09:10:55.000000000 +1000
@@ -22,6 +22,8 @@
#define nlm_lck_blocked __constant_htonl(NLM_LCK_BLOCKED)
#define nlm_lck_denied_grace_period __constant_htonl(NLM_LCK_DENIED_GRACE_PERIOD)

+#define nlm_drop_reply __constant_htonl(30000)
+
/* Lock info passed via NLM */
struct nlm_lock {
char * caller;

diff .prev/include/linux/sunrpc/msg_prot.h ./include/linux/sunrpc/msg_prot.h
--- .prev/include/linux/sunrpc/msg_prot.h 2006-10-17 09:10:55.000000000 +1000
+++ ./include/linux/sunrpc/msg_prot.h 2006-10-17 09:10:55.000000000 +1000
@@ -56,7 +56,9 @@ enum rpc_accept_stat {
RPC_PROG_MISMATCH = 2,
RPC_PROC_UNAVAIL = 3,
RPC_GARBAGE_ARGS = 4,
- RPC_SYSTEM_ERR = 5
+ RPC_SYSTEM_ERR = 5,
+ /* internal use only */
+ RPC_DROP_REPLY = 60000,
};

enum rpc_reject_stat {

diff .prev/include/linux/sunrpc/xdr.h ./include/linux/sunrpc/xdr.h
--- .prev/include/linux/sunrpc/xdr.h 2006-10-17 09:10:55.000000000 +1000
+++ ./include/linux/sunrpc/xdr.h 2006-10-17 09:10:55.000000000 +1000
@@ -74,6 +74,7 @@ struct xdr_buf {
#define rpc_proc_unavail __constant_htonl(RPC_PROC_UNAVAIL)
#define rpc_garbage_args __constant_htonl(RPC_GARBAGE_ARGS)
#define rpc_system_err __constant_htonl(RPC_SYSTEM_ERR)
+#define rpc_drop_reply __constant_htonl(RPC_DROP_REPLY)

#define rpc_auth_ok __constant_htonl(RPC_AUTH_OK)
#define rpc_autherr_badcred __constant_htonl(RPC_AUTH_BADCRED)

diff .prev/net/sunrpc/svc.c ./net/sunrpc/svc.c
--- .prev/net/sunrpc/svc.c 2006-10-17 09:10:55.000000000 +1000
+++ ./net/sunrpc/svc.c 2006-10-17 09:10:55.000000000 +1000
@@ -828,6 +828,11 @@ svc_process(struct svc_rqst *rqstp)
*statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);

/* Encode reply */
+ if (*statp == rpc_drop_reply) {
+ if (procp->pc_release)
+ procp->pc_release(rqstp, NULL, rqstp->rq_resp);
+ goto dropit;
+ }
if (*statp == rpc_success && (xdr = procp->pc_encode)
&& !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
dprintk("svc: failed to encode reply\n");
-
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Next message: NeilBrown: "[PATCH 002 of 5] knfsd: nfsd4: fix open permission checking"
Previous message: NeilBrown: "[PATCH 004 of 5] knfsd: Fix bug in recent lockd patches that can cause reclaim to fail."
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