Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: Fix panic after nfs_umount()
  nfs: remove extraneous and problematic calls to nfs_clear_request
  nfs: kernel should return EPROTONOSUPPORT when not support NFSv4
  NFS: Fix fcntl F_GETLK not reporting some conflicts
  nfs: Discard ACL cache on mode update
  NFS: Readdir cleanups
  NFS: nfs_readdir_search_for_cookie() don't mark as eof if cookie not found
  NFS: Fix a memory leak in nfs_readdir
  Call the filesystem back whenever a page is removed from the page cache
  NFS: Ensure we use the correct cookie in nfs_readdir_xdr_filler
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index a91f308..b6426f1 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -173,12 +173,13 @@
 	sector_t (*bmap)(struct address_space *, sector_t);
 	int (*invalidatepage) (struct page *, unsigned long);
 	int (*releasepage) (struct page *, int);
+	void (*freepage)(struct page *);
 	int (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
 			loff_t offset, unsigned long nr_segs);
 	int (*launder_page) (struct page *);
 
 locking rules:
-	All except set_page_dirty may block
+	All except set_page_dirty and freepage may block
 
 			BKL	PageLocked(page)	i_mutex
 writepage:		no	yes, unlocks (see below)
@@ -193,6 +194,7 @@
 bmap:			no
 invalidatepage:		no	yes
 releasepage:		no	yes
+freepage:		no	yes
 direct_IO:		no
 launder_page:		no	yes
 
@@ -288,6 +290,9 @@
 indicate that the buffers are (or may be) freeable.  If ->releasepage is zero,
 the kernel assumes that the fs has no private interest in the buffers.
 
+	->freepage() is called when the kernel is done dropping the page
+from the page cache.
+
 	->launder_page() may be called prior to releasing a page if
 it is still found to be dirty. It returns zero if the page was successfully
 cleaned, or an error value if not. Note that in order to prevent the page
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 55c28b7..20899e0 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -534,6 +534,7 @@
 	sector_t (*bmap)(struct address_space *, sector_t);
 	int (*invalidatepage) (struct page *, unsigned long);
 	int (*releasepage) (struct page *, int);
+	void (*freepage)(struct page *);
 	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
 			loff_t offset, unsigned long nr_segs);
 	struct page* (*get_xip_page)(struct address_space *, sector_t,
@@ -678,6 +679,12 @@
         need to ensure this.  Possibly it can clear the PageUptodate
         bit if it cannot free private data yet.
 
+  freepage: freepage is called once the page is no longer visible in
+        the page cache in order to allow the cleanup of any private
+	data. Since it may be called by the memory reclaimer, it
+	should not assume that the original address_space mapping still
+	exists, and it should not block.
+
   direct_IO: called by the generic read/write routines to perform
         direct_IO - that is IO requests which bypass the page cache
         and transfer data directly between the storage and the
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f0a384e..996dd89 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -57,7 +57,7 @@
 		      struct inode *, struct dentry *);
 static int nfs_fsync_dir(struct file *, int);
 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
-static int nfs_readdir_clear_array(struct page*, gfp_t);
+static void nfs_readdir_clear_array(struct page*);
 
 const struct file_operations nfs_dir_operations = {
 	.llseek		= nfs_llseek_dir,
@@ -83,8 +83,8 @@
 	.setattr	= nfs_setattr,
 };
 
-const struct address_space_operations nfs_dir_addr_space_ops = {
-	.releasepage = nfs_readdir_clear_array,
+const struct address_space_operations nfs_dir_aops = {
+	.freepage = nfs_readdir_clear_array,
 };
 
 #ifdef CONFIG_NFS_V3
@@ -178,6 +178,7 @@
 	struct page	*page;
 	unsigned long	page_index;
 	u64		*dir_cookie;
+	u64		last_cookie;
 	loff_t		current_index;
 	decode_dirent_t	decode;
 
@@ -213,17 +214,15 @@
  * we are freeing strings created by nfs_add_to_readdir_array()
  */
 static
-int nfs_readdir_clear_array(struct page *page, gfp_t mask)
+void nfs_readdir_clear_array(struct page *page)
 {
-	struct nfs_cache_array *array = nfs_readdir_get_array(page);
+	struct nfs_cache_array *array;
 	int i;
 
-	if (IS_ERR(array))
-		return PTR_ERR(array);
+	array = kmap_atomic(page, KM_USER0);
 	for (i = 0; i < array->size; i++)
 		kfree(array->array[i].string.name);
-	nfs_readdir_release_array(page);
-	return 0;
+	kunmap_atomic(array, KM_USER0);
 }
 
 /*
@@ -272,7 +271,7 @@
 		goto out;
 	array->last_cookie = entry->cookie;
 	array->size++;
-	if (entry->eof == 1)
+	if (entry->eof != 0)
 		array->eof_index = array->size;
 out:
 	nfs_readdir_release_array(page);
@@ -312,15 +311,14 @@
 	for (i = 0; i < array->size; i++) {
 		if (array->array[i].cookie == *desc->dir_cookie) {
 			desc->cache_entry_index = i;
-			status = 0;
-			goto out;
+			return 0;
 		}
 	}
-	if (i == array->eof_index) {
-		desc->eof = 1;
+	if (array->eof_index >= 0) {
 		status = -EBADCOOKIE;
+		if (*desc->dir_cookie == array->last_cookie)
+			desc->eof = 1;
 	}
-out:
 	return status;
 }
 
@@ -328,10 +326,7 @@
 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
 {
 	struct nfs_cache_array *array;
-	int status = -EBADCOOKIE;
-
-	if (desc->dir_cookie == NULL)
-		goto out;
+	int status;
 
 	array = nfs_readdir_get_array(desc->page);
 	if (IS_ERR(array)) {
@@ -344,6 +339,10 @@
 	else
 		status = nfs_readdir_search_for_cookie(array, desc);
 
+	if (status == -EAGAIN) {
+		desc->last_cookie = array->last_cookie;
+		desc->page_index++;
+	}
 	nfs_readdir_release_array(desc->page);
 out:
 	return status;
@@ -490,7 +489,7 @@
 
 		count++;
 
-		if (desc->plus == 1)
+		if (desc->plus != 0)
 			nfs_prime_dcache(desc->file->f_path.dentry, entry);
 
 		status = nfs_readdir_add_to_array(entry, page);
@@ -498,7 +497,7 @@
 			break;
 	} while (!entry->eof);
 
-	if (count == 0 || (status == -EBADCOOKIE && entry->eof == 1)) {
+	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
 		array = nfs_readdir_get_array(page);
 		if (!IS_ERR(array)) {
 			array->eof_index = array->size;
@@ -563,7 +562,7 @@
 	unsigned int array_size = ARRAY_SIZE(pages);
 
 	entry.prev_cookie = 0;
-	entry.cookie = *desc->dir_cookie;
+	entry.cookie = desc->last_cookie;
 	entry.eof = 0;
 	entry.fh = nfs_alloc_fhandle();
 	entry.fattr = nfs_alloc_fattr();
@@ -636,6 +635,8 @@
 static
 void cache_page_release(nfs_readdir_descriptor_t *desc)
 {
+	if (!desc->page->mapping)
+		nfs_readdir_clear_array(desc->page);
 	page_cache_release(desc->page);
 	desc->page = NULL;
 }
@@ -660,9 +661,8 @@
 		return PTR_ERR(desc->page);
 
 	res = nfs_readdir_search_array(desc);
-	if (res == 0)
-		return 0;
-	cache_page_release(desc);
+	if (res != 0)
+		cache_page_release(desc);
 	return res;
 }
 
@@ -672,22 +672,16 @@
 {
 	int res;
 
-	if (desc->page_index == 0)
+	if (desc->page_index == 0) {
 		desc->current_index = 0;
-	while (1) {
-		res = find_cache_page(desc);
-		if (res != -EAGAIN)
-			break;
-		desc->page_index++;
+		desc->last_cookie = 0;
 	}
+	do {
+		res = find_cache_page(desc);
+	} while (res == -EAGAIN);
 	return res;
 }
 
-static inline unsigned int dt_type(struct inode *inode)
-{
-	return (inode->i_mode >> 12) & 15;
-}
-
 /*
  * Once we've found the start of the dirent within a page: fill 'er up...
  */
@@ -717,13 +711,12 @@
 			break;
 		}
 		file->f_pos++;
-		desc->cache_entry_index = i;
 		if (i < (array->size-1))
 			*desc->dir_cookie = array->array[i+1].cookie;
 		else
 			*desc->dir_cookie = array->last_cookie;
 	}
-	if (i == array->eof_index)
+	if (array->eof_index >= 0)
 		desc->eof = 1;
 
 	nfs_readdir_release_array(desc->page);
@@ -764,6 +757,7 @@
 	}
 
 	desc->page_index = 0;
+	desc->last_cookie = *desc->dir_cookie;
 	desc->page = page;
 
 	status = nfs_readdir_xdr_to_array(desc, page, inode);
@@ -791,7 +785,7 @@
 	struct inode	*inode = dentry->d_inode;
 	nfs_readdir_descriptor_t my_desc,
 			*desc = &my_desc;
-	int res = -ENOMEM;
+	int res;
 
 	dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
 			dentry->d_parent->d_name.name, dentry->d_name.name,
@@ -816,7 +810,7 @@
 	if (res < 0)
 		goto out;
 
-	while (desc->eof != 1) {
+	do {
 		res = readdir_search_pagecache(desc);
 
 		if (res == -EBADCOOKIE) {
@@ -844,7 +838,7 @@
 		res = nfs_do_filldir(desc, dirent, filldir);
 		if (res < 0)
 			break;
-	}
+	} while (!desc->eof);
 out:
 	nfs_unblock_sillyrename(dentry);
 	if (res > 0)
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 60677f9..7bf029e 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -693,6 +693,7 @@
 {
 	struct inode *inode = filp->f_mapping->host;
 	int status = 0;
+	unsigned int saved_type = fl->fl_type;
 
 	/* Try local locking first */
 	posix_test_lock(filp, fl);
@@ -700,6 +701,7 @@
 		/* found a conflict */
 		goto out;
 	}
+	fl->fl_type = saved_type;
 
 	if (nfs_have_delegation(inode, FMODE_READ))
 		goto out_noconflict;
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 314f571..e67e31c 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -289,6 +289,7 @@
 		} else if (S_ISDIR(inode->i_mode)) {
 			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
 			inode->i_fop = &nfs_dir_operations;
+			inode->i_data.a_ops = &nfs_dir_aops;
 			if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS))
 				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
 			/* Deal with crossing mountpoints */
diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index eceafe7..4f981f1 100644
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -505,13 +505,13 @@
 
 static struct rpc_version mnt_version1 = {
 	.number		= 1,
-	.nrprocs	= 2,
+	.nrprocs	= ARRAY_SIZE(mnt_procedures),
 	.procs		= mnt_procedures,
 };
 
 static struct rpc_version mnt_version3 = {
 	.number		= 3,
-	.nrprocs	= 2,
+	.nrprocs	= ARRAY_SIZE(mnt3_procedures),
 	.procs		= mnt3_procedures,
 };
 
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6a653ff..4435e5e 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3361,6 +3361,8 @@
 	ret = nfs_revalidate_inode(server, inode);
 	if (ret < 0)
 		return ret;
+	if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
+		nfs_zap_acl_cache(inode);
 	ret = nfs4_read_cached_acl(inode, buf, buflen);
 	if (ret != -ENOENT)
 		return ret;
@@ -3389,6 +3391,13 @@
 	nfs_inode_return_delegation(inode);
 	buf_to_pages(buf, buflen, arg.acl_pages, &arg.acl_pgbase);
 	ret = nfs4_call_sync(server, &msg, &arg, &res, 1);
+	/*
+	 * Acl update can result in inode attribute update.
+	 * so mark the attribute cache invalid.
+	 */
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
+	spin_unlock(&inode->i_lock);
 	nfs_access_zap_cache(inode);
 	nfs_zap_acl_cache(inode);
 	return ret;
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 137b549..b68536c 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -115,7 +115,7 @@
 {
 	if (!nfs_lock_request_dontget(req))
 		return 0;
-	if (req->wb_page != NULL)
+	if (test_bit(PG_MAPPED, &req->wb_flags))
 		radix_tree_tag_set(&NFS_I(req->wb_context->path.dentry->d_inode)->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);
 	return 1;
 }
@@ -125,7 +125,7 @@
  */
 void nfs_clear_page_tag_locked(struct nfs_page *req)
 {
-	if (req->wb_page != NULL) {
+	if (test_bit(PG_MAPPED, &req->wb_flags)) {
 		struct inode *inode = req->wb_context->path.dentry->d_inode;
 		struct nfs_inode *nfsi = NFS_I(inode);
 
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index e4b62c6..aedcaa7 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -152,7 +152,6 @@
 			(long long)NFS_FILEID(req->wb_context->path.dentry->d_inode),
 			req->wb_bytes,
 			(long long)req_offset(req));
-	nfs_clear_request(req);
 	nfs_release_request(req);
 }
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 3c04504..4100630 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1069,12 +1069,10 @@
 			mnt->flags |= NFS_MOUNT_VER3;
 			mnt->version = 3;
 			break;
-#ifdef CONFIG_NFS_V4
 		case Opt_v4:
 			mnt->flags &= ~NFS_MOUNT_VER3;
 			mnt->version = 4;
 			break;
-#endif
 		case Opt_udp:
 			mnt->flags &= ~NFS_MOUNT_TCP;
 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
@@ -1286,12 +1284,10 @@
 				mnt->flags |= NFS_MOUNT_VER3;
 				mnt->version = 3;
 				break;
-#ifdef CONFIG_NFS_V4
 			case NFS4_VERSION:
 				mnt->flags &= ~NFS_MOUNT_VER3;
 				mnt->version = 4;
 				break;
-#endif
 			default:
 				goto out_invalid_value;
 			}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 4c14c17..10d648e 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -390,6 +390,7 @@
 		if (nfs_have_delegation(inode, FMODE_WRITE))
 			nfsi->change_attr++;
 	}
+	set_bit(PG_MAPPED, &req->wb_flags);
 	SetPagePrivate(req->wb_page);
 	set_page_private(req->wb_page, (unsigned long)req);
 	nfsi->npages++;
@@ -415,6 +416,7 @@
 	spin_lock(&inode->i_lock);
 	set_page_private(req->wb_page, 0);
 	ClearPagePrivate(req->wb_page);
+	clear_bit(PG_MAPPED, &req->wb_flags);
 	radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
 	nfsi->npages--;
 	if (!nfsi->npages) {
@@ -422,7 +424,6 @@
 		iput(inode);
 	} else
 		spin_unlock(&inode->i_lock);
-	nfs_clear_request(req);
 	nfs_release_request(req);
 }
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c9e06cc..090f0ea 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -602,6 +602,7 @@
 	sector_t (*bmap)(struct address_space *, sector_t);
 	void (*invalidatepage) (struct page *, unsigned long);
 	int (*releasepage) (struct page *, gfp_t);
+	void (*freepage)(struct page *);
 	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
 			loff_t offset, unsigned long nr_segs);
 	int (*get_xip_mem)(struct address_space *, pgoff_t, int,
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index c66fdb7..29d504d 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -401,6 +401,7 @@
 #endif /* CONFIG_NFS_V3 */
 extern const struct file_operations nfs_file_operations;
 extern const struct address_space_operations nfs_file_aops;
+extern const struct address_space_operations nfs_dir_aops;
 
 static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 {
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index f8b60e7..d55cee7 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -29,6 +29,7 @@
  */
 enum {
 	PG_BUSY = 0,
+	PG_MAPPED,
 	PG_CLEAN,
 	PG_NEED_COMMIT,
 	PG_NEED_RESCHED,
diff --git a/mm/filemap.c b/mm/filemap.c
index ea89840..6b9aee2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -143,13 +143,18 @@
 void remove_from_page_cache(struct page *page)
 {
 	struct address_space *mapping = page->mapping;
+	void (*freepage)(struct page *);
 
 	BUG_ON(!PageLocked(page));
 
+	freepage = mapping->a_ops->freepage;
 	spin_lock_irq(&mapping->tree_lock);
 	__remove_from_page_cache(page);
 	spin_unlock_irq(&mapping->tree_lock);
 	mem_cgroup_uncharge_cache_page(page);
+
+	if (freepage)
+		freepage(page);
 }
 EXPORT_SYMBOL(remove_from_page_cache);
 
diff --git a/mm/truncate.c b/mm/truncate.c
index ba887bf..3c2d5dd 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -390,6 +390,10 @@
 	__remove_from_page_cache(page);
 	spin_unlock_irq(&mapping->tree_lock);
 	mem_cgroup_uncharge_cache_page(page);
+
+	if (mapping->a_ops->freepage)
+		mapping->a_ops->freepage(page);
+
 	page_cache_release(page);	/* pagecache ref */
 	return 1;
 failed:
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d31d7ce..9ca587c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -494,9 +494,16 @@
 		spin_unlock_irq(&mapping->tree_lock);
 		swapcache_free(swap, page);
 	} else {
+		void (*freepage)(struct page *);
+
+		freepage = mapping->a_ops->freepage;
+
 		__remove_from_page_cache(page);
 		spin_unlock_irq(&mapping->tree_lock);
 		mem_cgroup_uncharge_cache_page(page);
+
+		if (freepage != NULL)
+			freepage(page);
 	}
 
 	return 1;