Merge tag 'nfsd-5.1' of git://linux-nfs.org/~bfields/linux

Pull NFS server updates from Bruce Fields:
 "Miscellaneous NFS server fixes.

  Probably the most visible bug is one that could artificially limit
  NFSv4.1 performance by limiting the number of oustanding rpcs from a
  single client.

  Neil Brown also gets a special mention for fixing a 14.5-year-old
  memory-corruption bug in the encoding of NFSv3 readdir responses"

* tag 'nfsd-5.1' of git://linux-nfs.org/~bfields/linux:
  nfsd: allow nfsv3 readdir request to be larger.
  nfsd: fix wrong check in write_v4_end_grace()
  nfsd: fix memory corruption caused by readdir
  nfsd: fix performance-limiting session calculation
  svcrpc: fix UDP on servers with lots of threads
  svcrdma: Remove syslog warnings in work completion handlers
  svcrdma: Squelch compiler warning when SUNRPC_DEBUG is disabled
  svcrdma: Use struct_size() in kmalloc()
  svcrpc: fix unlikely races preventing queueing of sockets
  svcrpc: svc_xprt_has_something_to_do seems a little long
  SUNRPC: Don't allow compiler optimisation of svc_xprt_release_slot()
  nfsd: fix an IS_ERR() vs NULL check

fs/nfsd/nfs3proc.c

@@ -463,8 +463,19 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
 					&resp->common, nfs3svc_encode_entry);
 	memcpy(resp->verf, argp->verf, 8);
 	resp->count = resp->buffer - argp->buffer;
-	if (resp->offset)
-		xdr_encode_hyper(resp->offset, argp->cookie);
+	if (resp->offset) {
+		loff_t offset = argp->cookie;
+
+		if (unlikely(resp->offset1)) {
+			/* we ended up with offset on a page boundary */
+			*resp->offset = htonl(offset >> 32);
+			*resp->offset1 = htonl(offset & 0xffffffff);
+			resp->offset1 = NULL;
+		} else {
+			xdr_encode_hyper(resp->offset, offset);
+		}
+		resp->offset = NULL;
+	}
 
 	RETURN_STATUS(nfserr);
 }
@@ -533,6 +544,7 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 		} else {
 			xdr_encode_hyper(resp->offset, offset);
 		}
+		resp->offset = NULL;
 	}
 
 	RETURN_STATUS(nfserr);
@@ -576,7 +588,7 @@ nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
 	resp->f_wtmax  = max_blocksize;
 	resp->f_wtpref = max_blocksize;
 	resp->f_wtmult = PAGE_SIZE;
-	resp->f_dtpref = PAGE_SIZE;
+	resp->f_dtpref = max_blocksize;
 	resp->f_maxfilesize = ~(u32) 0;
 	resp->f_properties = NFS3_FSF_DEFAULT;
 

fs/nfsd/nfs3xdr.c

@@ -573,6 +573,8 @@ int
 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
+	u32 max_blocksize = svc_max_payload(rqstp);
+
 	p = decode_fh(p, &args->fh);
 	if (!p)
 		return 0;
@@ -580,7 +582,7 @@ nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 	args->verf   = p; p += 2;
 	args->dircount = ~0;
 	args->count  = ntohl(*p++);
-	args->count  = min_t(u32, args->count, PAGE_SIZE);
+	args->count  = min_t(u32, args->count, max_blocksize);
 	args->buffer = page_address(*(rqstp->rq_next_page++));
 
 	return xdr_argsize_check(rqstp, p);
@@ -921,6 +923,7 @@ encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
 		} else {
 			xdr_encode_hyper(cd->offset, offset64);
 		}
+		cd->offset = NULL;
 	}
 
 	/*

fs/nfsd/nfs4callback.c

@@ -900,9 +900,9 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 		return PTR_ERR(client);
 	}
 	cred = get_backchannel_cred(clp, client, ses);
-	if (IS_ERR(cred)) {
+	if (!cred) {
 		rpc_shutdown_client(client);
-		return PTR_ERR(cred);
+		return -ENOMEM;
 	}
 	clp->cl_cb_client = client;
 	clp->cl_cb_cred = cred;

fs/nfsd/nfs4state.c

@@ -1544,16 +1544,16 @@ static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca)
 {
 	u32 slotsize = slot_bytes(ca);
 	u32 num = ca->maxreqs;
-	int avail;
+	unsigned long avail, total_avail;
 
 	spin_lock(&nfsd_drc_lock);
-	avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION,
-		    nfsd_drc_max_mem - nfsd_drc_mem_used);
+	total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used;
+	avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, total_avail);
 	/*
 	 * Never use more than a third of the remaining memory,
 	 * unless it's the only way to give this client a slot:
 	 */
-	avail = clamp_t(int, avail, slotsize, avail/3);
+	avail = clamp_t(int, avail, slotsize, total_avail/3);
 	num = min_t(int, num, avail / slotsize);
 	nfsd_drc_mem_used += num * slotsize;
 	spin_unlock(&nfsd_drc_lock);

fs/nfsd/nfsctl.c

@@ -1126,7 +1126,7 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
 		case 'Y':
 		case 'y':
 		case '1':
-			if (nn->nfsd_serv)
+			if (!nn->nfsd_serv)
 				return -EBUSY;
 			nfsd4_end_grace(nn);
 			break;