[PATCH] cifs: add new helper function for fscache conversion

[Steve French <smfrench@xxxxxxxxx>]

Add new helper to check if fscache enabled for cifs inode

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
 fs/cifs/file.c    | 7 +++++++
 fs/cifs/fscache.h | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 4b8c1ac58f00..49e7cf701b3e 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4287,6 +4287,13 @@ cifs_readpages_copy_into_pages(struct
TCP_Server_Info *server,
  return readpages_fill_pages(server, rdata, iter, iter->count);
 }

+static bool cifs_is_cache_enabled(struct inode *inode)
+{
+ struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+
+ return fscache_cookie_enabled(cookie) &&
!hlist_empty(&cookie->backing_objects);
+}
+
 static int
 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
      unsigned int rsize, struct list_head *tmplist,
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index e811f2dd7619..713c0da1bad0 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -70,6 +70,10 @@ extern void
cifs_fscache_release_inode_cookie(struct inode *);
 extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
 extern void cifs_fscache_reset_inode_cookie(struct inode *);

+static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
+{
+ return CIFS_I(inode)->fscache;
+}
 extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
 extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
 extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
@@ -138,6 +142,7 @@ static inline void
cifs_fscache_release_inode_cookie(struct inode *inode) {}
 static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
  struct file *filp) {}
 static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
+static inline struct fscache_cookie *cifs_inode_cookie(struct inode
*inode) { return NULL; }
 static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
 {
  return 1; /* May release page */

-- 
Thanks,

Steve

From 0f9488f68edbaf63db9f56e241d038685921630d Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@xxxxxxxxxx>
Date: Thu, 4 Feb 2021 01:23:04 -0600
Subject: [PATCH] cifs: add new helper function for fscache conversion

Add new helper to check if fscache enabled for cifs inode

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
 fs/cifs/file.c    | 7 +++++++
 fs/cifs/fscache.h | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 4b8c1ac58f00..49e7cf701b3e 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4287,6 +4287,13 @@ cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
 	return readpages_fill_pages(server, rdata, iter, iter->count);
 }
 
+static bool cifs_is_cache_enabled(struct inode *inode)
+{
+	struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+
+	return fscache_cookie_enabled(cookie) && !hlist_empty(&cookie->backing_objects);
+}
+
 static int
 readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 		    unsigned int rsize, struct list_head *tmplist,
diff --git a/fs/cifs/fscache.h b/fs/cifs/fscache.h
index e811f2dd7619..713c0da1bad0 100644
--- a/fs/cifs/fscache.h
+++ b/fs/cifs/fscache.h
@@ -70,6 +70,10 @@ extern void cifs_fscache_release_inode_cookie(struct inode *);
 extern void cifs_fscache_set_inode_cookie(struct inode *, struct file *);
 extern void cifs_fscache_reset_inode_cookie(struct inode *);
 
+static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode)
+{
+	return CIFS_I(inode)->fscache;
+}
 extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);
 extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);
 extern int __cifs_readpage_from_fscache(struct inode *, struct page *);
@@ -138,6 +142,7 @@ static inline void cifs_fscache_release_inode_cookie(struct inode *inode) {}
 static inline void cifs_fscache_set_inode_cookie(struct inode *inode,
 						 struct file *filp) {}
 static inline void cifs_fscache_reset_inode_cookie(struct inode *inode) {}
+static inline struct fscache_cookie *cifs_inode_cookie(struct inode *inode) { return NULL; }
 static inline int cifs_fscache_release_page(struct page *page, gfp_t gfp)
 {
 	return 1; /* May release page */
-- 
2.27.0