Merge tag '9p-for-5.16-rc1' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Fixes, netfs read support and checkpatch rewrite:

   - fix syzcaller uninitialized value usage after missing error check

   - add module autoloading based on transport name

   - convert cached reads to use netfs helpers

   - adjust readahead based on transport msize

   - and many, many checkpatch.pl warning fixes..."

* tag '9p-for-5.16-rc1' of git://github.com/martinetd/linux:
  9p: fix a bunch of checkpatch warnings
  9p: set readahead and io size according to maxsize
  9p p9mode2perm: remove useless strlcpy and check sscanf return code
  9p v9fs_parse_options: replace simple_strtoul with kstrtouint
  9p: fix file headers
  fs/9p: fix indentation and Add missing a blank line after declaration
  fs/9p: fix warnings found by checkpatch.pl
  9p: fix minor indentation and codestyle
  fs/9p: cleanup: opening brace at the beginning of the next line
  9p: Convert to using the netfs helper lib to do reads and caching
  fscache_cookie_enabled: check cookie is valid before accessing it
  net/9p: autoload transport modules
  9p/net: fix missing error check in p9_check_errors

18 files changed, 214 insertions, 442 deletions

diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig
index 09fd4a185fd2..d7bc93447c85 100644
--- a/fs/9p/Kconfig
+++ b/fs/9p/Kconfig
@@ -2,6 +2,7 @@
 config 9P_FS
 	tristate "Plan 9 Resource Sharing Support (9P2000)"
 	depends on INET && NET_9P
+	select NETFS_SUPPORT
 	help
 	  If you say Y here, you will get experimental support for
 	  Plan 9 resource sharing via the 9P2000 protocol.
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index c381499f5416..4dac4a0dc5f4 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: LGPL-2.1
 /*
  * Copyright IBM Corporation, 2010
  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
  */
 
 #include <linux/module.h>
@@ -123,6 +115,7 @@ static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl)
 	char *name;
 	size_t size;
 	void *buffer;
+
 	if (!acl)
 		return 0;
 
diff --git a/fs/9p/acl.h b/fs/9p/acl.h
index d43c8949e807..ce5175d463dd 100644
--- a/fs/9p/acl.h
+++ b/fs/9p/acl.h
@@ -1,28 +1,21 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
 /*
  * Copyright IBM Corporation, 2010
  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
  */
 #ifndef FS_9P_ACL_H
 #define FS_9P_ACL_H
 
 #ifdef CONFIG_9P_FS_POSIX_ACL
-extern int v9fs_get_acl(struct inode *, struct p9_fid *);
-extern struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type, bool rcu);
-extern int v9fs_acl_chmod(struct inode *, struct p9_fid *);
-extern int v9fs_set_create_acl(struct inode *, struct p9_fid *,
-			       struct posix_acl *, struct posix_acl *);
-extern int v9fs_acl_mode(struct inode *dir, umode_t *modep,
-			 struct posix_acl **dpacl, struct posix_acl **pacl);
-extern void v9fs_put_acl(struct posix_acl *dacl, struct posix_acl *acl);
+int v9fs_get_acl(struct inode *inode, struct p9_fid *fid);
+struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type,
+				   bool rcu);
+int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid);
+int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid,
+			struct posix_acl *dacl, struct posix_acl *acl);
+int v9fs_acl_mode(struct inode *dir, umode_t *modep,
+		  struct posix_acl **dpacl, struct posix_acl **pacl);
+void v9fs_put_acl(struct posix_acl *dacl, struct posix_acl *acl);
 #else
 #define v9fs_iop_get_acl NULL
 static inline int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
diff --git a/fs/9p/cache.c b/fs/9p/cache.c
index 1769a44f4819..f2ba131cede1 100644
--- a/fs/9p/cache.c
+++ b/fs/9p/cache.c
@@ -19,8 +19,8 @@
 #define CACHETAG_LEN  11
 
 struct fscache_netfs v9fs_cache_netfs = {
-	.name 		= "9p",
-	.version 	= 0,
+	.name		= "9p",
+	.version	= 0,
 };
 
 /*
@@ -199,140 +199,3 @@ void v9fs_cache_inode_reset_cookie(struct inode *inode)
 
 	mutex_unlock(&v9inode->fscache_lock);
 }
-
-int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
-{
-	struct inode *inode = page->mapping->host;
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	BUG_ON(!v9inode->fscache);
-
-	return fscache_maybe_release_page(v9inode->fscache, page, gfp);
-}
-
-void __v9fs_fscache_invalidate_page(struct page *page)
-{
-	struct inode *inode = page->mapping->host;
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	BUG_ON(!v9inode->fscache);
-
-	if (PageFsCache(page)) {
-		fscache_wait_on_page_write(v9inode->fscache, page);
-		BUG_ON(!PageLocked(page));
-		fscache_uncache_page(v9inode->fscache, page);
-	}
-}
-
-static void v9fs_vfs_readpage_complete(struct page *page, void *data,
-				       int error)
-{
-	if (!error)
-		SetPageUptodate(page);
-
-	unlock_page(page);
-}
-
-/*
- * __v9fs_readpage_from_fscache - read a page from cache
- *
- * Returns 0 if the pages are in cache and a BIO is submitted,
- * 1 if the pages are not in cache and -error otherwise.
- */
-
-int __v9fs_readpage_from_fscache(struct inode *inode, struct page *page)
-{
-	int ret;
-	const struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
-	if (!v9inode->fscache)
-		return -ENOBUFS;
-
-	ret = fscache_read_or_alloc_page(v9inode->fscache,
-					 page,
-					 v9fs_vfs_readpage_complete,
-					 NULL,
-					 GFP_KERNEL);
-	switch (ret) {
-	case -ENOBUFS:
-	case -ENODATA:
-		p9_debug(P9_DEBUG_FSC, "page/inode not in cache %d\n", ret);
-		return 1;
-	case 0:
-		p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
-		return ret;
-	default:
-		p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
-		return ret;
-	}
-}
-
-/*
- * __v9fs_readpages_from_fscache - read multiple pages from cache
- *
- * Returns 0 if the pages are in cache and a BIO is submitted,
- * 1 if the pages are not in cache and -error otherwise.
- */
-
-int __v9fs_readpages_from_fscache(struct inode *inode,
-				  struct address_space *mapping,
-				  struct list_head *pages,
-				  unsigned *nr_pages)
-{
-	int ret;
-	const struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	p9_debug(P9_DEBUG_FSC, "inode %p pages %u\n", inode, *nr_pages);
-	if (!v9inode->fscache)
-		return -ENOBUFS;
-
-	ret = fscache_read_or_alloc_pages(v9inode->fscache,
-					  mapping, pages, nr_pages,
-					  v9fs_vfs_readpage_complete,
-					  NULL,
-					  mapping_gfp_mask(mapping));
-	switch (ret) {
-	case -ENOBUFS:
-	case -ENODATA:
-		p9_debug(P9_DEBUG_FSC, "pages/inodes not in cache %d\n", ret);
-		return 1;
-	case 0:
-		BUG_ON(!list_empty(pages));
-		BUG_ON(*nr_pages != 0);
-		p9_debug(P9_DEBUG_FSC, "BIO submitted\n");
-		return ret;
-	default:
-		p9_debug(P9_DEBUG_FSC, "ret %d\n", ret);
-		return ret;
-	}
-}
-
-/*
- * __v9fs_readpage_to_fscache - write a page to the cache
- *
- */
-
-void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page)
-{
-	int ret;
-	const struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
-	ret = fscache_write_page(v9inode->fscache, page,
-				 i_size_read(&v9inode->vfs_inode), GFP_KERNEL);
-	p9_debug(P9_DEBUG_FSC, "ret =  %d\n", ret);
-	if (ret != 0)
-		v9fs_uncache_page(inode, page);
-}
-
-/*
- * wait for a page to complete writing to the cache
- */
-void __v9fs_fscache_wait_on_page_write(struct inode *inode, struct page *page)
-{
-	const struct v9fs_inode *v9inode = V9FS_I(inode);
-	p9_debug(P9_DEBUG_FSC, "inode %p page %p\n", inode, page);
-	if (PageFsCache(page))
-		fscache_wait_on_page_write(v9inode->fscache, page);
-}
diff --git a/fs/9p/cache.h b/fs/9p/cache.h
index 00f107af443e..7480b4b49fea 100644
--- a/fs/9p/cache.h
+++ b/fs/9p/cache.h
@@ -7,9 +7,10 @@
 
 #ifndef _9P_CACHE_H
 #define _9P_CACHE_H
-#ifdef CONFIG_9P_FSCACHE
+#define FSCACHE_USE_NEW_IO_API
 #include <linux/fscache.h>
-#include <linux/spinlock.h>
+
+#ifdef CONFIG_9P_FSCACHE
 
 extern struct fscache_netfs v9fs_cache_netfs;
 extern const struct fscache_cookie_def v9fs_cache_session_index_def;
@@ -27,64 +28,6 @@ extern void v9fs_cache_inode_reset_cookie(struct inode *inode);
 extern int __v9fs_cache_register(void);
 extern void __v9fs_cache_unregister(void);
 
-extern int __v9fs_fscache_release_page(struct page *page, gfp_t gfp);
-extern void __v9fs_fscache_invalidate_page(struct page *page);
-extern int __v9fs_readpage_from_fscache(struct inode *inode,
-					struct page *page);
-extern int __v9fs_readpages_from_fscache(struct inode *inode,
-					 struct address_space *mapping,
-					 struct list_head *pages,
-					 unsigned *nr_pages);
-extern void __v9fs_readpage_to_fscache(struct inode *inode, struct page *page);
-extern void __v9fs_fscache_wait_on_page_write(struct inode *inode,
-					      struct page *page);
-
-static inline int v9fs_fscache_release_page(struct page *page,
-					    gfp_t gfp)
-{
-	return __v9fs_fscache_release_page(page, gfp);
-}
-
-static inline void v9fs_fscache_invalidate_page(struct page *page)
-{
-	__v9fs_fscache_invalidate_page(page);
-}
-
-static inline int v9fs_readpage_from_fscache(struct inode *inode,
-					     struct page *page)
-{
-	return __v9fs_readpage_from_fscache(inode, page);
-}
-
-static inline int v9fs_readpages_from_fscache(struct inode *inode,
-					      struct address_space *mapping,
-					      struct list_head *pages,
-					      unsigned *nr_pages)
-{
-	return __v9fs_readpages_from_fscache(inode, mapping, pages,
-					     nr_pages);
-}
-
-static inline void v9fs_readpage_to_fscache(struct inode *inode,
-					    struct page *page)
-{
-	if (PageFsCache(page))
-		__v9fs_readpage_to_fscache(inode, page);
-}
-
-static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
-{
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-	fscache_uncache_page(v9inode->fscache, page);
-	BUG_ON(PageFsCache(page));
-}
-
-static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
-						   struct page *page)
-{
-	return __v9fs_fscache_wait_on_page_write(inode, page);
-}
-
 #else /* CONFIG_9P_FSCACHE */
 
 static inline void v9fs_cache_inode_get_cookie(struct inode *inode)
@@ -99,39 +42,5 @@ static inline void v9fs_cache_inode_set_cookie(struct inode *inode, struct file
 {
 }
 
-static inline int v9fs_fscache_release_page(struct page *page,
-					    gfp_t gfp) {
-	return 1;
-}
-
-static inline void v9fs_fscache_invalidate_page(struct page *page) {}
-
-static inline int v9fs_readpage_from_fscache(struct inode *inode,
-					     struct page *page)
-{
-	return -ENOBUFS;
-}
-
-static inline int v9fs_readpages_from_fscache(struct inode *inode,
-					      struct address_space *mapping,
-					      struct list_head *pages,
-					      unsigned *nr_pages)
-{
-	return -ENOBUFS;
-}
-
-static inline void v9fs_readpage_to_fscache(struct inode *inode,
-					    struct page *page)
-{}
-
-static inline void v9fs_uncache_page(struct inode *inode, struct page *page)
-{}
-
-static inline void v9fs_fscache_wait_on_page_write(struct inode *inode,
-						   struct page *page)
-{
-	return;
-}
-
 #endif /* CONFIG_9P_FSCACHE */
 #endif /* _9P_CACHE_H */
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index b8863dd0de5c..6aab046c98e2 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -103,6 +103,7 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
 	/* we'll recheck under lock if there's anything to look in */
 	if (!ret && dentry->d_fsdata) {
 		struct hlist_head *h = (struct hlist_head *)&dentry->d_fsdata;
+
 		spin_lock(&dentry->d_lock);
 		hlist_for_each_entry(fid, h, dlist) {
 			if (any || uid_eq(fid->uid, uid)) {
@@ -185,7 +186,7 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
 			return ERR_PTR(-EPERM);
 
 		if (v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses))
-				uname = NULL;
+			uname = NULL;
 		else
 			uname = v9ses->uname;
 
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 2e0fa7c932db..e32dd5f7721b 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/v9fs.c
- *
  *  This file contains functions assisting in mapping VFS to 9P2000
  *
  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -166,7 +164,7 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
 	int option = 0;
-	char *s, *e;
+	char *s;
 	int ret = 0;
 
 	/* setup defaults */
@@ -190,8 +188,10 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token, r;
+
 		if (!*p)
 			continue;
+
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_debug:
@@ -321,12 +321,13 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 				v9ses->flags |= V9FS_ACCESS_CLIENT;
 			} else {
 				uid_t uid;
+
 				v9ses->flags |= V9FS_ACCESS_SINGLE;
-				uid = simple_strtoul(s, &e, 10);
-				if (*e != '\0') {
-					ret = -EINVAL;
-					pr_info("Unknown access argument %s\n",
-						s);
+				r = kstrtouint(s, 10, &uid);
+				if (r) {
+					ret = r;
+					pr_info("Unknown access argument %s: %d\n",
+						s, r);
 					kfree(s);
 					continue;
 				}
@@ -520,7 +521,8 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
  * mark transport as disconnected and cancel all pending requests.
  */
 
-void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
+void v9fs_session_cancel(struct v9fs_session_info *v9ses)
+{
 	p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 	p9_client_disconnect(v9ses->clnt);
 }
@@ -659,6 +661,7 @@ static void v9fs_destroy_inode_cache(void)
 static int v9fs_cache_register(void)
 {
 	int ret;
+
 	ret = v9fs_init_inode_cache();
 	if (ret < 0)
 		return ret;
@@ -686,6 +689,7 @@ static void v9fs_cache_unregister(void)
 static int __init init_v9fs(void)
 {
 	int err;
+
 	pr_info("Installing v9fs 9p2000 file system support\n");
 	/* TODO: Setup list of registered trasnport modules */
 
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 4ca56c5dd637..1647a8e63671 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -124,15 +124,24 @@ static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 	return container_of(inode, struct v9fs_inode, vfs_inode);
 }
 
+static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
+{
+#ifdef CONFIG_9P_FSCACHE
+	return v9inode->fscache;
+#else
+	return NULL;
+#endif
+}
+
 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
 
-struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
-									char *);
+struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
+				 const char *dev_name, char *data);
 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
-			unsigned int flags);
+				      unsigned int flags);
 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
@@ -158,7 +167,7 @@ extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 
 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 {
-	return (inode->i_sb->s_fs_info);
+	return inode->i_sb->s_fs_info;
 }
 
 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index d44ade76966a..bc417da7e9c1 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -44,9 +44,10 @@ extern struct kmem_cache *v9fs_inode_cache;
 
 struct inode *v9fs_alloc_inode(struct super_block *sb);
 void v9fs_free_inode(struct inode *inode);
-struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t);
+struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode,
+			     dev_t rdev);
 int v9fs_init_inode(struct v9fs_session_info *v9ses,
-		    struct inode *inode, umode_t mode, dev_t);
+		    struct inode *inode, umode_t mode, dev_t rdev);
 void v9fs_evict_inode(struct inode *inode);
 ino_t v9fs_qid2ino(struct p9_qid *qid);
 void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
@@ -59,8 +60,8 @@ void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 int v9fs_uflags2omode(int uflags, int extended);
 
 void v9fs_blank_wstat(struct p9_wstat *wstat);
-int v9fs_vfs_setattr_dotl(struct user_namespace *, struct dentry *,
-			  struct iattr *);
+int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+			  struct dentry *dentry, struct iattr *iattr);
 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
 			 int datasync);
 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
@@ -68,9 +69,9 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
 {
 	struct v9fs_inode *v9inode;
+
 	v9inode = V9FS_I(inode);
 	v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
-	return;
 }
 
 int v9fs_open_to_dotl_flags(int flags);
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 1c4f1b39cc95..adafdf86f42f 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_addr.c
- *
  * This file contians vfs address (mmap) ops for 9P2000.
  *
  *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -19,7 +17,7 @@
 #include <linux/idr.h>
 #include <linux/sched.h>
 #include <linux/uio.h>
-#include <linux/bvec.h>
+#include <linux/netfs.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -29,88 +27,97 @@
 #include "fid.h"
 
 /**
- * v9fs_fid_readpage - read an entire page in from 9P
- * @data: Opaque pointer to the fid being read
- * @page: structure to page
- *
+ * v9fs_req_issue_op - Issue a read from 9P
+ * @subreq: The read to make
  */
-static int v9fs_fid_readpage(void *data, struct page *page)
+static void v9fs_req_issue_op(struct netfs_read_subrequest *subreq)
 {
-	struct p9_fid *fid = data;
-	struct inode *inode = page->mapping->host;
-	struct bio_vec bvec = {.bv_page = page, .bv_len = PAGE_SIZE};
+	struct netfs_read_request *rreq = subreq->rreq;
+	struct p9_fid *fid = rreq->netfs_priv;
 	struct iov_iter to;
-	int retval, err;
+	loff_t pos = subreq->start + subreq->transferred;
+	size_t len = subreq->len   - subreq->transferred;
+	int total, err;
 
-	p9_debug(P9_DEBUG_VFS, "\n");
+	iov_iter_xarray(&to, READ, &rreq->mapping->i_pages, pos, len);
 
-	BUG_ON(!PageLocked(page));
+	total = p9_client_read(fid, pos, &to, &err);
+	netfs_subreq_terminated(subreq, err ?: total, false);
+}
 
-	retval = v9fs_readpage_from_fscache(inode, page);
-	if (retval == 0)
-		return retval;
+/**
+ * v9fs_init_rreq - Initialise a read request
+ * @rreq: The read request
+ * @file: The file being read from
+ */
+static void v9fs_init_rreq(struct netfs_read_request *rreq, struct file *file)
+{
+	struct p9_fid *fid = file->private_data;
 
-	iov_iter_bvec(&to, READ, &bvec, 1, PAGE_SIZE);
+	refcount_inc(&fid->count);
+	rreq->netfs_priv = fid;
+}
 
-	retval = p9_client_read(fid, page_offset(page), &to, &err);
-	if (err) {
-		v9fs_uncache_page(inode, page);
-		retval = err;
-		goto done;
-	}
+/**
+ * v9fs_req_cleanup - Cleanup request initialized by v9fs_init_rreq
+ * @mapping: unused mapping of request to cleanup
+ * @priv: private data to cleanup, a fid, guaranted non-null.
+ */
+static void v9fs_req_cleanup(struct address_space *mapping, void *priv)
+{
+	struct p9_fid *fid = priv;
 
-	zero_user(page, retval, PAGE_SIZE - retval);
-	flush_dcache_page(page);
-	SetPageUptodate(page);
+	p9_client_clunk(fid);
+}
 
-	v9fs_readpage_to_fscache(inode, page);
-	retval = 0;
+/**
+ * v9fs_is_cache_enabled - Determine if caching is enabled for an inode
+ * @inode: The inode to check
+ */
+static bool v9fs_is_cache_enabled(struct inode *inode)
+{
+	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(inode));
 
-done:
-	unlock_page(page);
-	return retval;
+	return fscache_cookie_enabled(cookie) && !hlist_empty(&cookie->backing_objects);
 }
 
 /**
+ * v9fs_begin_cache_operation - Begin a cache operation for a read
+ * @rreq: The read request
+ */
+static int v9fs_begin_cache_operation(struct netfs_read_request *rreq)
+{
+	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode));
+
+	return fscache_begin_read_operation(rreq, cookie);
+}
+
+static const struct netfs_read_request_ops v9fs_req_ops = {
+	.init_rreq		= v9fs_init_rreq,
+	.is_cache_enabled	= v9fs_is_cache_enabled,
+	.begin_cache_operation	= v9fs_begin_cache_operation,
+	.issue_op		= v9fs_req_issue_op,
+	.cleanup		= v9fs_req_cleanup,
+};
+
+/**
  * v9fs_vfs_readpage - read an entire page in from 9P
- *
- * @filp: file being read
+ * @file: file being read
  * @page: structure to page
  *
  */
-
-static int v9fs_vfs_readpage(struct file *filp, struct page *page)
+static int v9fs_vfs_readpage(struct file *file, struct page *page)
 {
-	return v9fs_fid_readpage(filp->private_data, page);
+	return netfs_readpage(file, page, &v9fs_req_ops, NULL);
 }
 
 /**
- * v9fs_vfs_readpages - read a set of pages from 9P
- *
- * @filp: file being read
- * @mapping: the address space
- * @pages: list of pages to read
- * @nr_pages: count of pages to read
- *
+ * v9fs_vfs_readahead - read a set of pages from 9P
+ * @ractl: The readahead parameters
  */
-
-static int v9fs_vfs_readpages(struct file *filp, struct address_space *mapping,
-			     struct list_head *pages, unsigned nr_pages)
+static void v9fs_vfs_readahead(struct readahead_control *ractl)
 {
-	int ret = 0;
-	struct inode *inode;
-
-	inode = mapping->host;
-	p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, filp);
-
-	ret = v9fs_readpages_from_fscache(inode, mapping, pages, &nr_pages);
-	if (ret == 0)
-		return ret;
-
-	ret = read_cache_pages(mapping, pages, v9fs_fid_readpage,
-			filp->private_data);
-	p9_debug(P9_DEBUG_VFS, "  = %d\n", ret);
-	return ret;
+	netfs_readahead(ractl, &v9fs_req_ops, NULL);
 }
 
 /**
@@ -125,7 +132,14 @@ static int v9fs_release_page(struct page *page, gfp_t gfp)
 {
 	if (PagePrivate(page))
 		return 0;
-	return v9fs_fscache_release_page(page, gfp);
+#ifdef CONFIG_9P_FSCACHE
+	if (PageFsCache(page)) {
+		if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS))
+			return 0;
+		wait_on_page_fscache(page);
+	}
+#endif
+	return 1;
 }
 
 /**
@@ -138,21 +152,16 @@ static int v9fs_release_page(struct page *page, gfp_t gfp)
 static void v9fs_invalidate_page(struct page *page, unsigned int offset,
 				 unsigned int length)
 {
-	/*
-	 * If called with zero offset, we should release
-	 * the private state assocated with the page
-	 */
-	if (offset == 0 && length == PAGE_SIZE)
-		v9fs_fscache_invalidate_page(page);
+	wait_on_page_fscache(page);
 }
 
 static int v9fs_vfs_writepage_locked(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	struct v9fs_inode *v9inode = V9FS_I(inode);
+	loff_t start = page_offset(page);
 	loff_t size = i_size_read(inode);
 	struct iov_iter from;
-	struct bio_vec bvec;
 	int err, len;
 
 	if (page->index == size >> PAGE_SHIFT)
@@ -160,17 +169,14 @@ static int v9fs_vfs_writepage_locked(struct page *page)
 	else
 		len = PAGE_SIZE;
 
-	bvec.bv_page = page;
-	bvec.bv_offset = 0;
-	bvec.bv_len = len;
-	iov_iter_bvec(&from, WRITE, &bvec, 1, len);
+	iov_iter_xarray(&from, WRITE, &page->mapping->i_pages, start, len);
 
 	/* We should have writeback_fid always set */
 	BUG_ON(!v9inode->writeback_fid);
 
 	set_page_writeback(page);
 
-	p9_client_write(v9inode->writeback_fid, page_offset(page), &from, &err);
+	p9_client_write(v9inode->writeback_fid, start, &from, &err);
 
 	end_page_writeback(page);
 	return err;
@@ -208,14 +214,13 @@ static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)
 static int v9fs_launder_page(struct page *page)
 {
 	int retval;
-	struct inode *inode = page->mapping->host;
 
-	v9fs_fscache_wait_on_page_write(inode, page);
 	if (clear_page_dirty_for_io(page)) {
 		retval = v9fs_vfs_writepage_locked(page);
 		if (retval)
 			return retval;
 	}
+	wait_on_page_fscache(page);
 	return 0;
 }
 
@@ -242,11 +247,13 @@ v9fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	loff_t pos = iocb->ki_pos;
 	ssize_t n;
 	int err = 0;
+
 	if (iov_iter_rw(iter) == WRITE) {
 		n = p9_client_write(file->private_data, pos, iter, &err);
 		if (n) {
 			struct inode *inode = file_inode(file);
 			loff_t i_size = i_size_read(inode);
+
 			if (pos + n > i_size)
 				inode_add_bytes(inode, pos + n - i_size);
 		}
@@ -257,43 +264,32 @@ v9fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 }
 
 static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
-			    loff_t pos, unsigned len, unsigned flags,
+			    loff_t pos, unsigned int len, unsigned int flags,
 			    struct page **pagep, void **fsdata)
 {
-	int retval = 0;
+	int retval;
 	struct page *page;
-	struct v9fs_inode *v9inode;
-	pgoff_t index = pos >> PAGE_SHIFT;
-	struct inode *inode = mapping->host;
-
+	struct v9fs_inode *v9inode = V9FS_I(mapping->host);
 
 	p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
 
-	v9inode = V9FS_I(inode);
-start:
-	page = grab_cache_page_write_begin(mapping, index, flags);
-	if (!page) {
-		retval = -ENOMEM;
-		goto out;
-	}
 	BUG_ON(!v9inode->writeback_fid);
-	if (PageUptodate(page))
-		goto out;
 
-	if (len == PAGE_SIZE)
-		goto out;
+	/* Prefetch area to be written into the cache if we're caching this
+	 * file.  We need to do this before we get a lock on the page in case
+	 * there's more than one writer competing for the same cache block.
+	 */
+	retval = netfs_write_begin(filp, mapping, pos, len, flags, &page, fsdata,
+				   &v9fs_req_ops, NULL);
+	if (retval < 0)
+		return retval;
 
-	retval = v9fs_fid_readpage(v9inode->writeback_fid, page);
-	put_page(page);
-	if (!retval)
-		goto start;
-out:
-	*pagep = page;
+	*pagep = find_subpage(page, pos / PAGE_SIZE);
 	return retval;
 }
 
 static int v9fs_write_end(struct file *filp, struct address_space *mapping,
-			  loff_t pos, unsigned len, unsigned copied,
+			  loff_t pos, unsigned int len, unsigned int copied,
 			  struct page *page, void *fsdata)
 {
 	loff_t last_pos = pos + copied;
@@ -305,10 +301,11 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping,
 		if (unlikely(copied < len)) {
 			copied = 0;
 			goto out;
-		} else if (len == PAGE_SIZE) {
-			SetPageUptodate(page);
 		}
+
+		SetPageUptodate(page);
 	}
+
 	/*
 	 * No need to use i_size_read() here, the i_size
 	 * cannot change under us because we hold the i_mutex.
@@ -328,7 +325,7 @@ out:
 
 const struct address_space_operations v9fs_addr_operations = {
 	.readpage = v9fs_vfs_readpage,
-	.readpages = v9fs_vfs_readpages,
+	.readahead = v9fs_vfs_readahead,
 	.set_page_dirty = __set_page_dirty_nobuffers,
 	.writepage = v9fs_vfs_writepage,
 	.write_begin = v9fs_write_begin,
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index 4b4292123b3d..1c609e99d280 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_dentry.c
- *
  * This file contians vfs dentry ops for the 9P2000 protocol.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -52,6 +50,7 @@ static int v9fs_cached_dentry_delete(const struct dentry *dentry)
 static void v9fs_dentry_release(struct dentry *dentry)
 {
 	struct hlist_node *p, *n;
+
 	p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
 		 dentry, dentry);
 	hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
@@ -76,6 +75,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 	if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
 		int retval;
 		struct v9fs_session_info *v9ses;
+
 		fid = v9fs_fid_lookup(dentry);
 		if (IS_ERR(fid))
 			return PTR_ERR(fid);
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index b6a5a0be444d..8c854d8cb0cd 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * linux/fs/9p/vfs_dir.c
- *
  * This file contains vfs directory ops for the 9P2000 protocol.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -71,6 +69,7 @@ static inline int dt_type(struct p9_wstat *mistat)
 static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen)
 {
 	struct p9_fid *fid = filp->private_data;
+
 	if (!fid->rdir)
 		fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
 	return fid->rdir;
@@ -108,6 +107,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 		if (rdir->tail == rdir->head) {
 			struct iov_iter to;
 			int n;
+
 			iov_iter_kvec(&to, READ, &kvec, 1, buflen);
 			n = p9_client_read(file->private_data, ctx->pos, &to,
 					   &err);
@@ -233,5 +233,5 @@ const struct file_operations v9fs_dir_operations_dotl = {
 	.iterate_shared = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
-        .fsync = v9fs_file_fsync_dotl,
+	.fsync = v9fs_file_fsync_dotl,
 };
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 246235ebdb70..4244d48398ef 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_file.c
- *
  * This file contians vfs file ops for 9P2000.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -408,6 +406,7 @@ v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		struct inode *inode = file_inode(file);
 		loff_t i_size;
 		unsigned long pg_start, pg_end;
+
 		pg_start = origin >> PAGE_SHIFT;
 		pg_end = (origin + retval - 1) >> PAGE_SHIFT;
 		if (inode->i_mapping && inode->i_mapping->nrpages)
@@ -537,14 +536,23 @@ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
 	p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n",
 		 page, (unsigned long)filp->private_data);
 
+	v9inode = V9FS_I(inode);
+
+	/* Wait for the page to be written to the cache before we allow it to
+	 * be modified.  We then assume the entire page will need writing back.
+	 */
+#ifdef CONFIG_9P_FSCACHE
+	if (PageFsCache(page) &&
+	    wait_on_page_fscache_killable(page) < 0)
+		return VM_FAULT_RETRY;
+#endif
+
 	/* Update file times before taking page lock */
 	file_update_time(filp);
 
-	v9inode = V9FS_I(inode);
-	/* make sure the cache has finished storing the page */
-	v9fs_fscache_wait_on_page_write(inode, page);
 	BUG_ON(!v9inode->writeback_fid);
-	lock_page(page);
+	if (lock_page_killable(page) < 0)
+		return VM_FAULT_RETRY;
 	if (page->mapping != inode->i_mapping)
 		goto out_unlock;
 	wait_for_stable_page(page);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 08f48b70a741..328c338ff304 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_inode.c
- *
  * This file contains vfs inode ops for the 9P2000 protocol.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -49,6 +47,7 @@ static const struct inode_operations v9fs_symlink_inode_operations;
 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
 {
 	int res;
+
 	res = mode & 0777;
 	if (S_ISDIR(mode))
 		res |= P9_DMDIR;
@@ -110,7 +109,7 @@ static int p9mode2perm(struct v9fs_session_info *v9ses,
 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 			       struct p9_wstat *stat, dev_t *rdev)
 {
-	int res;
+	int res, r;
 	u32 mode = stat->mode;
 
 	*rdev = 0;
@@ -128,11 +127,16 @@ static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 		res |= S_IFIFO;
 	else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 		 && (v9ses->nodev == 0)) {
-		char type = 0, ext[32];
+		char type = 0;
 		int major = -1, minor = -1;
 
-		strlcpy(ext, stat->extension, sizeof(ext));
-		sscanf(ext, "%c %i %i", &type, &major, &minor);
+		r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
+		if (r != 3) {
+			p9_debug(P9_DEBUG_ERROR,
+				 "invalid device string, umode will be bogus: %s\n",
+				 stat->extension);
+			return res;
+		}
 		switch (type) {
 		case 'c':
 			res |= S_IFCHR;
@@ -223,6 +227,7 @@ v9fs_blank_wstat(struct p9_wstat *wstat)
 struct inode *v9fs_alloc_inode(struct super_block *sb)
 {
 	struct v9fs_inode *v9inode;
+
 	v9inode = kmem_cache_alloc(v9fs_inode_cache, GFP_KERNEL);
 	if (!v9inode)
 		return NULL;
@@ -251,7 +256,7 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 {
 	int err = 0;
 
-	inode_init_owner(&init_user_ns,inode,  NULL, mode);
+	inode_init_owner(&init_user_ns, inode, NULL, mode);
 	inode->i_blocks = 0;
 	inode->i_rdev = rdev;
 	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
@@ -440,7 +445,7 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
 	unsigned long i_ino;
 	struct inode *inode;
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
-	int (*test)(struct inode *, void *);
+	int (*test)(struct inode *inode, void *data);
 
 	if (new)
 		test = v9fs_test_new_inode;
@@ -499,8 +504,10 @@ v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 static int v9fs_at_to_dotl_flags(int flags)
 {
 	int rflags = 0;
+
 	if (flags & AT_REMOVEDIR)
 		rflags |= P9_DOTL_AT_REMOVEDIR;
+
 	return rflags;
 }
 
@@ -797,7 +804,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 
 static int
 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
-		     struct file *file, unsigned flags, umode_t mode)
+		     struct file *file, unsigned int flags, umode_t mode)
 {
 	int err;
 	u32 perm;
@@ -1084,7 +1091,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
 		fid = v9fs_fid_lookup(dentry);
 		use_dentry = 1;
 	}
-	if(IS_ERR(fid))
+	if (IS_ERR(fid))
 		return PTR_ERR(fid);
 
 	v9fs_blank_wstat(&wstat);
@@ -1364,7 +1371,7 @@ v9fs_vfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 	char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
 	u32 perm;
 
-	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
+	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
 		 dir->i_ino, dentry, mode,
 		 MAJOR(rdev), MINOR(rdev));
 
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 01b9e1281a29..7dee89ba32e7 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_inode_dotl.c
- *
  * This file contains vfs inode ops for the 9P2000.L protocol.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
@@ -107,7 +105,7 @@ static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
 	unsigned long i_ino;
 	struct inode *inode;
 	struct v9fs_session_info *v9ses = sb->s_fs_info;
-	int (*test)(struct inode *, void *);
+	int (*test)(struct inode *inode, void *data);
 
 	if (new)
 		test = v9fs_test_new_inode_dotl;
@@ -230,7 +228,7 @@ v9fs_vfs_create_dotl(struct user_namespace *mnt_userns, struct inode *dir,
 
 static int
 v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
-			  struct file *file, unsigned flags, umode_t omode)
+			  struct file *file, unsigned int flags, umode_t omode)
 {
 	int err = 0;
 	kgid_t gid;
@@ -261,7 +259,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 	v9ses = v9fs_inode2v9ses(dir);
 
 	name = dentry->d_name.name;
-	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
+	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%x\n",
 		 name, flags, omode);
 
 	dfid = v9fs_parent_fid(dentry);
@@ -807,6 +805,7 @@ v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
 		/* Get the latest stat info from server. */
 		struct p9_fid *fid;
+
 		fid = v9fs_fid_lookup(old_dentry);
 		if (IS_ERR(fid))
 			return PTR_ERR(fid);
@@ -843,7 +842,7 @@ v9fs_vfs_mknod_dotl(struct user_namespace *mnt_userns, struct inode *dir,
 	struct p9_qid qid;
 	struct posix_acl *dacl = NULL, *pacl = NULL;
 
-	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
+	p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
 		 dir->i_ino, dentry, omode,
 		 MAJOR(rdev), MINOR(rdev));
 
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 5fce6e30bc5a..b739e02f5ef7 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -1,9 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/fs/9p/vfs_super.c
- *
- * This file contians superblock ops for 9P2000. It is intended that
- * you mount this file system on directories.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
@@ -83,6 +79,9 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
 	if (!v9ses->cache) {
 		sb->s_bdi->ra_pages = 0;
 		sb->s_bdi->io_pages = 0;
+	} else {
+		sb->s_bdi->ra_pages = v9ses->maxdata >> PAGE_SHIFT;
+		sb->s_bdi->io_pages = v9ses->maxdata >> PAGE_SHIFT;
 	}
 
 	sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
@@ -113,7 +112,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 	struct inode *inode = NULL;
 	struct dentry *root = NULL;
 	struct v9fs_session_info *v9ses = NULL;
-	umode_t mode = S_IRWXUGO | S_ISVTX;
+	umode_t mode = 0777 | S_ISVTX;
 	struct p9_fid *fid;
 	int retval = 0;
 
@@ -157,6 +156,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 	sb->s_root = root;
 	if (v9fs_proto_dotl(v9ses)) {
 		struct p9_stat_dotl *st = NULL;
+
 		st = p9_client_getattr_dotl(fid, P9_STATS_BASIC);
 		if (IS_ERR(st)) {
 			retval = PTR_ERR(st);
@@ -167,6 +167,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 		kfree(st);
 	} else {
 		struct p9_wstat *st = NULL;
+
 		st = p9_client_stat(fid);
 		if (IS_ERR(st)) {
 			retval = PTR_ERR(st);
@@ -275,12 +276,13 @@ done:
 static int v9fs_drop_inode(struct inode *inode)
 {
 	struct v9fs_session_info *v9ses;
+
 	v9ses = v9fs_inode2v9ses(inode);
 	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 		return generic_drop_inode(inode);
 	/*
 	 * in case of non cached mode always drop the
-	 * the inode because we want the inode attribute
+	 * inode because we want the inode attribute
 	 * to always match that on the server.
 	 */
 	return 1;
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index ee331845e2c7..a824441b95a2 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: LGPL-2.1
 /*
  * Copyright IBM Corporation, 2010
  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
  */
 
 #include <linux/module.h>
diff --git a/fs/9p/xattr.h b/fs/9p/xattr.h
index c63c3bea5de5..3e11fc3331eb 100644
--- a/fs/9p/xattr.h
+++ b/fs/9p/xattr.h
@@ -1,15 +1,7 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
 /*
  * Copyright IBM Corporation, 2010
  * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
  */
 #ifndef FS_9P_XATTR_H
 #define FS_9P_XATTR_H
@@ -22,13 +14,14 @@ extern const struct xattr_handler *v9fs_xattr_handlers[];
 extern const struct xattr_handler v9fs_xattr_acl_access_handler;
 extern const struct xattr_handler v9fs_xattr_acl_default_handler;
 
-extern ssize_t v9fs_fid_xattr_get(struct p9_fid *, const char *,
-				  void *, size_t);
-extern ssize_t v9fs_xattr_get(struct dentry *, const char *,
-			      void *, size_t);
-extern int v9fs_fid_xattr_set(struct p9_fid *, const char *,
-			  const void *, size_t, int);
-extern int v9fs_xattr_set(struct dentry *, const char *,
-			  const void *, size_t, int);
-extern ssize_t v9fs_listxattr(struct dentry *, char *, size_t);
+ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
+			   void *buffer, size_t buffer_size);
+ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name,
+		       void *buffer, size_t buffer_size);
+int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
+		       const void *value, size_t value_len, int flags);
+int v9fs_xattr_set(struct dentry *dentry, const char *name,
+		   const void *value, size_t value_len, int flags);
+ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer,
+		       size_t buffer_size);
 #endif /* FS_9P_XATTR_H */