Merge tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Trond made a change to the server's tcp logic that allows a fast
     client to better take advantage of high bandwidth networks, but may
     increase the risk that a single client could starve other clients;
     a new sunrpc.svc_rpc_per_connection_limit parameter should help
     mitigate this in the (hopefully unlikely) event this becomes a
     problem in practice.

   - Tom Haynes added a minimal flex-layout pnfs server, which is of no
     use in production for now--don't build it unless you're doing
     client testing or further server development"

* tag 'nfsd-4.8' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd: remove some dead code in nfsd_create_locked()
  nfsd: drop unnecessary MAY_EXEC check from create
  nfsd: clean up bad-type check in nfsd_create_locked
  nfsd: remove unnecessary positive-dentry check
  nfsd: reorganize nfsd_create
  nfsd: check d_can_lookup in fh_verify of directories
  nfsd: remove redundant zero-length check from create
  nfsd: Make creates return EEXIST instead of EACCES
  SUNRPC: Detect immediate closure of accepted sockets
  SUNRPC: accept() may return sockets that are still in SYN_RECV
  nfsd: allow nfsd to advertise multiple layout types
  nfsd: Close race between nfsd4_release_lockowner and nfsd4_lock
  nfsd/blocklayout: Make sure calculate signature/designator length aligned
  xfs: abstract block export operations from nfsd layouts
  SUNRPC: Remove unused callback xpo_adjust_wspace()
  SUNRPC: Change TCP socket space reservation
  SUNRPC: Add a server side per-connection limit
  SUNRPC: Micro optimisation for svc_data_ready
  SUNRPC: Call the default socket callbacks instead of open coding
  SUNRPC: lock the socket while detaching it
  ...

1 files changed, 62 insertions, 80 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6fbd81ecb410..ba944123167b 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1135,96 +1135,37 @@ nfsd_check_ignore_resizing(struct iattr *iap)
 		iap->ia_valid &= ~ATTR_SIZE;
 }
 
-/*
- * Create a file (regular, directory, device, fifo); UNIX sockets 
- * not yet implemented.
- * If the response fh has been verified, the parent directory should
- * already be locked. Note that the parent directory is left locked.
- *
- * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
- */
+/* The parent directory should already be locked: */
 __be32
-nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		char *fname, int flen, struct iattr *iap,
 		int type, dev_t rdev, struct svc_fh *resfhp)
 {
-	struct dentry	*dentry, *dchild = NULL;
+	struct dentry	*dentry, *dchild;
 	struct inode	*dirp;
 	__be32		err;
 	__be32		err2;
 	int		host_err;
 
-	err = nfserr_perm;
-	if (!flen)
-		goto out;
-	err = nfserr_exist;
-	if (isdotent(fname, flen))
-		goto out;
-
-	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
-	if (err)
-		goto out;
-
 	dentry = fhp->fh_dentry;
 	dirp = d_inode(dentry);
 
-	err = nfserr_notdir;
-	if (!dirp->i_op->lookup)
-		goto out;
-	/*
-	 * Check whether the response file handle has been verified yet.
-	 * If it has, the parent directory should already be locked.
-	 */
-	if (!resfhp->fh_dentry) {
-		host_err = fh_want_write(fhp);
-		if (host_err)
-			goto out_nfserr;
-
-		/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
-		fh_lock_nested(fhp, I_MUTEX_PARENT);
-		dchild = lookup_one_len(fname, dentry, flen);
-		host_err = PTR_ERR(dchild);
-		if (IS_ERR(dchild))
-			goto out_nfserr;
-		err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
-		if (err)
-			goto out;
-	} else {
-		/* called from nfsd_proc_create */
-		dchild = dget(resfhp->fh_dentry);
-		if (!fhp->fh_locked) {
-			/* not actually possible */
-			printk(KERN_ERR
-				"nfsd_create: parent %pd2 not locked!\n",
+	dchild = dget(resfhp->fh_dentry);
+	if (!fhp->fh_locked) {
+		WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
 				dentry);
-			err = nfserr_io;
-			goto out;
-		}
-	}
-	/*
-	 * Make sure the child dentry is still negative ...
-	 */
-	err = nfserr_exist;
-	if (d_really_is_positive(dchild)) {
-		dprintk("nfsd_create: dentry %pd/%pd not negative!\n",
-			dentry, dchild);
-		goto out; 
+		err = nfserr_io;
+		goto out;
 	}
 
+	err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
 	if (!(iap->ia_valid & ATTR_MODE))
 		iap->ia_mode = 0;
 	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
 
-	err = nfserr_inval;
-	if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
-		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
-		       type);
-		goto out;
-	}
-
-	/*
-	 * Get the dir op function pointer.
-	 */
 	err = 0;
 	host_err = 0;
 	switch (type) {
@@ -1242,6 +1183,10 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	case S_IFSOCK:
 		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
 		break;
+	default:
+		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
+		       type);
+		host_err = -EINVAL;
 	}
 	if (host_err < 0)
 		goto out_nfserr;
@@ -1251,7 +1196,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	/*
 	 * nfsd_create_setattr already committed the child.  Transactional
 	 * filesystems had a chance to commit changes for both parent and
-	 * child * simultaneously making the following commit_metadata a
+	 * child simultaneously making the following commit_metadata a
 	 * noop.
 	 */
 	err2 = nfserrno(commit_metadata(fhp));
@@ -1263,8 +1208,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (!err)
 		err = fh_update(resfhp);
 out:
-	if (dchild && !IS_ERR(dchild))
-		dput(dchild);
+	dput(dchild);
 	return err;
 
 out_nfserr:
@@ -1272,6 +1216,50 @@ out_nfserr:
 	goto out;
 }
 
+/*
+ * Create a filesystem object (regular, directory, special).
+ * Note that the parent directory is left locked.
+ *
+ * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
+ */
+__be32
+nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		char *fname, int flen, struct iattr *iap,
+		int type, dev_t rdev, struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dchild = NULL;
+	struct inode	*dirp;
+	__be32		err;
+	int		host_err;
+
+	if (isdotent(fname, flen))
+		return nfserr_exist;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
+	if (err)
+		return err;
+
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		return nfserrno(host_err);
+
+	fh_lock_nested(fhp, I_MUTEX_PARENT);
+	dchild = lookup_one_len(fname, dentry, flen);
+	host_err = PTR_ERR(dchild);
+	if (IS_ERR(dchild))
+		return nfserrno(host_err);
+	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+	if (err) {
+		dput(dchild);
+		return err;
+	}
+	return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
+					rdev, resfhp);
+}
+
 #ifdef CONFIG_NFSD_V3
 
 /*
@@ -1304,12 +1292,6 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	dentry = fhp->fh_dentry;
 	dirp = d_inode(dentry);
 
-	/* Get all the sanity checks out of the way before
-	 * we lock the parent. */
-	err = nfserr_notdir;
-	if (!dirp->i_op->lookup)
-		goto out;
-
 	host_err = fh_want_write(fhp);
 	if (host_err)
 		goto out_nfserr;