Merge tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6

Pull nfsd updates from Chuck Lever:
 "Several substantial changes this time around:

   - Previously, exporting an NFS mount via NFSD was considered to be an
     unsupported feature. With v5.11, the community has attempted to
     make re-exporting a first-class feature of NFSD.

     This would enable the Linux in-kernel NFS server to be used as an
     intermediate cache for a remotely-located primary NFS server, for
     example, even with other NFS server implementations, like a NetApp
     filer, as the primary.

   - A short series of patches brings support for multiple RPC/RDMA data
     chunks per RPC transaction to the Linux NFS server's RPC/RDMA
     transport implementation.

     This is a part of the RPC/RDMA spec that the other premiere
     NFS/RDMA implementation (Solaris) has had for a very long time, and
     completes the implementation of RPC/RDMA version 1 in the Linux
     kernel's NFS server.

   - Long ago, NFSv4 support was introduced to NFSD using a series of C
     macros that hid dprintk's and goto's. Over time, the kernel's XDR
     implementation has been greatly improved, but these C macros have
     remained and become fallow. A series of patches in this pull
     request completely replaces those macros with the use of current
     kernel XDR infrastructure. Benefits include:

       - More robust input sanitization in NFSD's NFSv4 XDR decoders.

       - Make it easier to use common kernel library functions that use
         XDR stream APIs (for example, GSS-API).

       - Align the structure of the source code with the RFCs so it is
         easier to learn, verify, and maintain our XDR implementation.

       - Removal of more than a hundred hidden dprintk() call sites.

       - Removal of some explicit manipulation of pages to help make the
         eventual transition to xdr->bvec smoother.

   - On top of several related fixes in 5.10-rc, there are a few more
     fixes to get the Linux NFSD implementation of NFSv4.2 inter-server
     copy up to speed.

  And as usual, there is a pinch of seasoning in the form of a
  collection of unrelated minor bug fixes and clean-ups.

  Many thanks to all who contributed this time around!"

* tag 'nfsd-5.11' of git://git.linux-nfs.org/projects/cel/cel-2.6: (131 commits)
  nfsd: Record NFSv4 pre/post-op attributes as non-atomic
  nfsd: Set PF_LOCAL_THROTTLE on local filesystems only
  nfsd: Fix up nfsd to ensure that timeout errors don't result in ESTALE
  exportfs: Add a function to return the raw output from fh_to_dentry()
  nfsd: close cached files prior to a REMOVE or RENAME that would replace target
  nfsd: allow filesystems to opt out of subtree checking
  nfsd: add a new EXPORT_OP_NOWCC flag to struct export_operations
  Revert "nfsd4: support change_attr_type attribute"
  nfsd4: don't query change attribute in v2/v3 case
  nfsd: minor nfsd4_change_attribute cleanup
  nfsd: simplify nfsd4_change_info
  nfsd: only call inode_query_iversion in the I_VERSION case
  nfs_common: need lock during iterate through the list
  NFSD: Fix 5 seconds delay when doing inter server copy
  NFSD: Fix sparse warning in nfs4proc.c
  SUNRPC: Remove XDRBUF_SPARSE_PAGES flag in gss_proxy upcall
  sunrpc: clean-up cache downcall
  nfsd: Fix message level for normal termination
  NFSD: Remove macros that are no longer used
  NFSD: Replace READ* macros in nfsd4_decode_compound()
  ...

Documentation/filesystems/nfs/exporting.rst

@@ -154,6 +154,11 @@ struct which has the following members:
     to find potential names, and matches inode numbers to find the correct
     match.
 
+  flags
+    Some filesystems may need to be handled differently than others. The
+    export_operations struct also includes a flags field that allows the
+    filesystem to communicate such information to nfsd. See the Export
+    Operations Flags section below for more explanation.
 
 A filehandle fragment consists of an array of 1 or more 4byte words,
 together with a one byte "type".
@@ -163,3 +168,50 @@ generated by encode_fh, in which case it will have been padded with
 nuls.  Rather, the encode_fh routine should choose a "type" which
 indicates the decode_fh how much of the filehandle is valid, and how
 it should be interpreted.
+
+Export Operations Flags
+-----------------------
+In addition to the operation vector pointers, struct export_operations also
+contains a "flags" field that allows the filesystem to communicate to nfsd
+that it may want to do things differently when dealing with it. The
+following flags are defined:
+
+  EXPORT_OP_NOWCC - disable NFSv3 WCC attributes on this filesystem
+    RFC 1813 recommends that servers always send weak cache consistency
+    (WCC) data to the client after each operation. The server should
+    atomically collect attributes about the inode, do an operation on it,
+    and then collect the attributes afterward. This allows the client to
+    skip issuing GETATTRs in some situations but means that the server
+    is calling vfs_getattr for almost all RPCs. On some filesystems
+    (particularly those that are clustered or networked) this is expensive
+    and atomicity is difficult to guarantee. This flag indicates to nfsd
+    that it should skip providing WCC attributes to the client in NFSv3
+    replies when doing operations on this filesystem. Consider enabling
+    this on filesystems that have an expensive ->getattr inode operation,
+    or when atomicity between pre and post operation attribute collection
+    is impossible to guarantee.
+
+  EXPORT_OP_NOSUBTREECHK - disallow subtree checking on this fs
+    Many NFS operations deal with filehandles, which the server must then
+    vet to ensure that they live inside of an exported tree. When the
+    export consists of an entire filesystem, this is trivial. nfsd can just
+    ensure that the filehandle live on the filesystem. When only part of a
+    filesystem is exported however, then nfsd must walk the ancestors of the
+    inode to ensure that it's within an exported subtree. This is an
+    expensive operation and not all filesystems can support it properly.
+    This flag exempts the filesystem from subtree checking and causes
+    exportfs to get back an error if it tries to enable subtree checking
+    on it.
+
+  EXPORT_OP_CLOSE_BEFORE_UNLINK - always close cached files before unlinking
+    On some exportable filesystems (such as NFS) unlinking a file that
+    is still open can cause a fair bit of extra work. For instance,
+    the NFS client will do a "sillyrename" to ensure that the file
+    sticks around while it's still open. When reexporting, that open
+    file is held by nfsd so we usually end up doing a sillyrename, and
+    then immediately deleting the sillyrenamed file just afterward when
+    the link count actually goes to zero. Sometimes this delete can race
+    with other operations (for instance an rmdir of the parent directory).
+    This flag causes nfsd to close any open files for this inode _before_
+    calling into the vfs to do an unlink or a rename that would replace
+    an existing file.

fs/exportfs/expfs.c

@@ -417,9 +417,11 @@ int exportfs_encode_fh(struct dentry *dentry, struct fid *fid, int *max_len,
 }
 EXPORT_SYMBOL_GPL(exportfs_encode_fh);
 
-struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
-		int fh_len, int fileid_type,
-		int (*acceptable)(void *, struct dentry *), void *context)
+struct dentry *
+exportfs_decode_fh_raw(struct vfsmount *mnt, struct fid *fid, int fh_len,
+		       int fileid_type,
+		       int (*acceptable)(void *, struct dentry *),
+		       void *context)
 {
 	const struct export_operations *nop = mnt->mnt_sb->s_export_op;
 	struct dentry *result, *alias;
@@ -432,10 +434,8 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 	if (!nop || !nop->fh_to_dentry)
 		return ERR_PTR(-ESTALE);
 	result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type);
-	if (PTR_ERR(result) == -ENOMEM)
-		return ERR_CAST(result);
 	if (IS_ERR_OR_NULL(result))
-		return ERR_PTR(-ESTALE);
+		return result;
 
 	/*
 	 * If no acceptance criteria was specified by caller, a disconnected
@@ -561,10 +561,26 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 
  err_result:
 	dput(result);
-	if (err != -ENOMEM)
-		err = -ESTALE;
 	return ERR_PTR(err);
 }
+EXPORT_SYMBOL_GPL(exportfs_decode_fh_raw);
+
+struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
+				  int fh_len, int fileid_type,
+				  int (*acceptable)(void *, struct dentry *),
+				  void *context)
+{
+	struct dentry *ret;
+
+	ret = exportfs_decode_fh_raw(mnt, fid, fh_len, fileid_type,
+				     acceptable, context);
+	if (IS_ERR_OR_NULL(ret)) {
+		if (ret == ERR_PTR(-ENOMEM))
+			return ret;
+		return ERR_PTR(-ESTALE);
+	}
+	return ret;
+}
 EXPORT_SYMBOL_GPL(exportfs_decode_fh);
 
 MODULE_LICENSE("GPL");

fs/nfs/blocklayout/blocklayout.c

@@ -697,7 +697,7 @@ bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
 
 	xdr_init_decode_pages(&xdr, &buf,
 			lgr->layoutp->pages, lgr->layoutp->len);
-	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&xdr, scratch);
 
 	status = -EIO;
 	p = xdr_inline_decode(&xdr, 4);

fs/nfs/blocklayout/dev.c

@@ -510,7 +510,7 @@ bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 		goto out;
 
 	xdr_init_decode_pages(&xdr, &buf, pdev->pages, pdev->pglen);
-	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&xdr, scratch);
 
 	p = xdr_inline_decode(&xdr, sizeof(__be32));
 	if (!p)

fs/nfs/dir.c

@@ -576,7 +576,7 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
 		goto out_nopages;
 
 	xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
-	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&stream, scratch);
 
 	do {
 		if (entry->label)

fs/nfs/export.c

@@ -171,4 +171,7 @@ const struct export_operations nfs_export_ops = {
 	.encode_fh = nfs_encode_fh,
 	.fh_to_dentry = nfs_fh_to_dentry,
 	.get_parent = nfs_get_parent,
+	.flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|
+		EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS|
+		EXPORT_OP_NOATOMIC_ATTR,
 };

fs/nfs/filelayout/filelayout.c

@@ -666,7 +666,7 @@ filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 		return -ENOMEM;
 
 	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
-	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&stream, scratch);
 
 	/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 	 * num_fh (4) */

fs/nfs/filelayout/filelayoutdev.c

@@ -82,7 +82,7 @@ nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 		goto out_err;
 
 	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
-	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&stream, scratch);
 
 	/* Get the stripe count (number of stripe index) */
 	p = xdr_inline_decode(&stream, 4);

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -378,7 +378,7 @@ ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
 
 	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
 			      lgr->layoutp->len);
-	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&stream, scratch);
 
 	/* stripe unit and mirror_array_cnt */
 	rc = -EIO;

fs/nfs/flexfilelayout/flexfilelayoutdev.c

@@ -69,7 +69,7 @@ nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
 	INIT_LIST_HEAD(&dsaddrs);
 
 	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
-	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+	xdr_set_scratch_page(&stream, scratch);
 
 	/* multipath count */
 	p = xdr_inline_decode(&stream, 4);

fs/nfs/nfs42xdr.c

@@ -1539,7 +1539,7 @@ static int nfs4_xdr_dec_listxattrs(struct rpc_rqst *rqstp,
 	struct compound_hdr hdr;
 	int status;
 
-	xdr_set_scratch_buffer(xdr, page_address(res->scratch), PAGE_SIZE);
+	xdr_set_scratch_page(xdr, res->scratch);
 
 	status = decode_compound_hdr(xdr, &hdr);
 	if (status)

fs/nfs/nfs4xdr.c

@@ -6403,10 +6403,8 @@ nfs4_xdr_dec_getacl(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
 	struct compound_hdr hdr;
 	int status;
 
-	if (res->acl_scratch != NULL) {
-		void *p = page_address(res->acl_scratch);
-		xdr_set_scratch_buffer(xdr, p, PAGE_SIZE);
-	}
+	if (res->acl_scratch != NULL)
+		xdr_set_scratch_page(xdr, res->acl_scratch);
 	status = decode_compound_hdr(xdr, &hdr);
 	if (status)
 		goto out;

fs/nfs_common/grace.c

@@ -69,10 +69,14 @@ __state_in_grace(struct net *net, bool open)
 	if (!open)
 		return !list_empty(grace_list);
 
+	spin_lock(&grace_lock);
 	list_for_each_entry(lm, grace_list, list) {
-		if (lm->block_opens)
+		if (lm->block_opens) {
+			spin_unlock(&grace_lock);
 			return true;
+		}
 	}
+	spin_unlock(&grace_lock);
 	return false;
 }
 

fs/nfsd/export.c

@@ -408,6 +408,12 @@ static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
 		return -EINVAL;
 	}
 
+	if (inode->i_sb->s_export_op->flags & EXPORT_OP_NOSUBTREECHK &&
+	    !(*flags & NFSEXP_NOSUBTREECHECK)) {
+		dprintk("%s: %s does not support subtree checking!\n",
+			__func__, inode->i_sb->s_type->name);
+		return -EINVAL;
+	}
 	return 0;
 
 }

fs/nfsd/filecache.c

@@ -685,6 +685,7 @@ nfsd_file_cache_init(void)
 	if (IS_ERR(nfsd_file_fsnotify_group)) {
 		pr_err("nfsd: unable to create fsnotify group: %ld\n",
 			PTR_ERR(nfsd_file_fsnotify_group));
+		ret = PTR_ERR(nfsd_file_fsnotify_group);
 		nfsd_file_fsnotify_group = NULL;
 		goto out_notifier;
 	}

fs/nfsd/nfs2acl.c

@@ -185,10 +185,6 @@ static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
 /*
  * XDR decode functions
  */
-static int nfsaclsvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
-{
-	return 1;
-}
 
 static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
 {
@@ -255,15 +251,6 @@ static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
  * XDR encode functions
  */
 
-/*
- * There must be an encoding function for void results so svc_process
- * will work properly.
- */
-static int nfsaclsvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
-{
-	return xdr_ressize_check(rqstp, p);
-}
-
 /* GETACL */
 static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
 {
@@ -378,10 +365,10 @@ struct nfsd3_voidargs { int dummy; };
 static const struct svc_procedure nfsd_acl_procedures2[5] = {
 	[ACLPROC2_NULL] = {
 		.pc_func = nfsacld_proc_null,
-		.pc_decode = nfsaclsvc_decode_voidarg,
-		.pc_encode = nfsaclsvc_encode_voidres,
-		.pc_argsize = sizeof(struct nfsd3_voidargs),
-		.pc_ressize = sizeof(struct nfsd3_voidargs),
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
 		.pc_cachetype = RC_NOCACHE,
 		.pc_xdrressize = ST,
 	},

fs/nfsd/nfs3acl.c

@@ -245,10 +245,10 @@ struct nfsd3_voidargs { int dummy; };
 static const struct svc_procedure nfsd_acl_procedures3[3] = {
 	[ACLPROC3_NULL] = {
 		.pc_func = nfsd3_proc_null,
-		.pc_decode = nfs3svc_decode_voidarg,
-		.pc_encode = nfs3svc_encode_voidres,
-		.pc_argsize = sizeof(struct nfsd3_voidargs),
-		.pc_ressize = sizeof(struct nfsd3_voidargs),
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
 		.pc_cachetype = RC_NOCACHE,
 		.pc_xdrressize = ST,
 	},

fs/nfsd/nfs3proc.c

@@ -689,12 +689,9 @@ nfsd3_proc_commit(struct svc_rqst *rqstp)
 #define nfsd3_mkdirargs			nfsd3_createargs
 #define nfsd3_readdirplusargs		nfsd3_readdirargs
 #define nfsd3_fhandleargs		nfsd_fhandle
-#define nfsd3_fhandleres		nfsd3_attrstat
 #define nfsd3_attrstatres		nfsd3_attrstat
 #define nfsd3_wccstatres		nfsd3_attrstat
 #define nfsd3_createres			nfsd3_diropres
-#define nfsd3_voidres			nfsd3_voidargs
-struct nfsd3_voidargs { int dummy; };
 
 #define ST 1		/* status*/
 #define FH 17		/* filehandle with length */
@@ -705,10 +702,10 @@ struct nfsd3_voidargs { int dummy; };
 static const struct svc_procedure nfsd_procedures3[22] = {
 	[NFS3PROC_NULL] = {
 		.pc_func = nfsd3_proc_null,
-		.pc_decode = nfs3svc_decode_voidarg,
-		.pc_encode = nfs3svc_encode_voidres,
-		.pc_argsize = sizeof(struct nfsd3_voidargs),
-		.pc_ressize = sizeof(struct nfsd3_voidres),
+		.pc_decode = nfssvc_decode_voidarg,
+		.pc_encode = nfssvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd_voidargs),
+		.pc_ressize = sizeof(struct nfsd_voidres),
 		.pc_cachetype = RC_NOCACHE,
 		.pc_xdrressize = ST,
 	},