ceph: conversion to new fscache API

Now that the fscache API has been reworked and simplified, change ceph
over to use it.

With the old API, we would only instantiate a cookie when the file was
open for reads. Change it to instantiate the cookie when the inode is
instantiated and call use/unuse when the file is opened/closed.

Also, ensure we resize the cached data on truncates, and invalidate the
cache in response to the appropriate events. This will allow us to
plumb in write support later.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20211129162907.149445-2-jlayton@kernel.org/ # v1
Link: https://lore.kernel.org/r/20211207134451.66296-2-jlayton@kernel.org/ # v2
Link: https://lore.kernel.org/r/163906984277.143852.14697110691303589000.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967188351.1823006.5065634844099079351.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021581427.640689.14128682147127509264.stgit@warthog.procyon.org.uk/ # v4

1 files changed, 68 insertions, 29 deletions

diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h
index 058ea2a04376..09164389fa66 100644
--- a/fs/ceph/cache.h
+++ b/fs/ceph/cache.h
@@ -12,19 +12,19 @@
 #include <linux/netfs.h>
 
 #ifdef CONFIG_CEPH_FSCACHE
-
-extern struct fscache_netfs ceph_cache_netfs;
-
-int ceph_fscache_register(void);
-void ceph_fscache_unregister(void);
+#include <linux/fscache.h>
 
 int ceph_fscache_register_fs(struct ceph_fs_client* fsc, struct fs_context *fc);
 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc);
 
 void ceph_fscache_register_inode_cookie(struct inode *inode);
 void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci);
-void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp);
-void ceph_fscache_revalidate_cookie(struct ceph_inode_info *ci);
+
+void ceph_fscache_use_cookie(struct inode *inode, bool will_modify);
+void ceph_fscache_unuse_cookie(struct inode *inode, bool update);
+
+void ceph_fscache_update(struct inode *inode);
+void ceph_fscache_invalidate(struct inode *inode, bool dio_write);
 
 static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
@@ -36,37 +36,51 @@ static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info
 	return ci->fscache;
 }
 
-static inline void ceph_fscache_invalidate(struct inode *inode)
+static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
 {
-	fscache_invalidate(ceph_inode(inode)->fscache);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct fscache_cookie *cookie = ceph_fscache_cookie(ci);
+
+	if (cookie) {
+		ceph_fscache_use_cookie(inode, true);
+		fscache_resize_cookie(cookie, to);
+		ceph_fscache_unuse_cookie(inode, true);
+	}
 }
 
-static inline bool ceph_is_cache_enabled(struct inode *inode)
+static inline void ceph_fscache_unpin_writeback(struct inode *inode,
+						struct writeback_control *wbc)
 {
-	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(inode));
+	fscache_unpin_writeback(wbc, ceph_fscache_cookie(ceph_inode(inode)));
+}
+
+static inline int ceph_fscache_set_page_dirty(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	struct ceph_inode_info *ci = ceph_inode(inode);
 
-	if (!cookie)
-		return false;
-	return fscache_cookie_enabled(cookie);
+	return fscache_set_page_dirty(page, ceph_fscache_cookie(ci));
 }
 
 static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
 {
 	struct fscache_cookie *cookie = ceph_fscache_cookie(ceph_inode(rreq->inode));
 
-	return fscache_begin_read_operation(rreq, cookie);
+	return fscache_begin_read_operation(&rreq->cache_resources, cookie);
 }
-#else
 
-static inline int ceph_fscache_register(void)
+static inline bool ceph_is_cache_enabled(struct inode *inode)
 {
-	return 0;
+	return fscache_cookie_enabled(ceph_fscache_cookie(ceph_inode(inode)));
 }
 
-static inline void ceph_fscache_unregister(void)
+static inline void ceph_fscache_note_page_release(struct inode *inode)
 {
-}
+	struct ceph_inode_info *ci = ceph_inode(inode);
 
+	fscache_note_page_release(ceph_fscache_cookie(ci));
+}
+#else /* CONFIG_CEPH_FSCACHE */
 static inline int ceph_fscache_register_fs(struct ceph_fs_client* fsc,
 					   struct fs_context *fc)
 {
@@ -81,28 +95,49 @@ static inline void ceph_fscache_inode_init(struct ceph_inode_info *ci)
 {
 }
 
-static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
+static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
-	return NULL;
 }
 
-static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
+static inline void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
 {
 }
 
-static inline void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
+static inline void ceph_fscache_use_cookie(struct inode *inode, bool will_modify)
 {
 }
 
-static inline void ceph_fscache_file_set_cookie(struct inode *inode,
-						struct file *filp)
+static inline void ceph_fscache_unuse_cookie(struct inode *inode, bool update)
 {
 }
 
-static inline void ceph_fscache_invalidate(struct inode *inode)
+static inline void ceph_fscache_update(struct inode *inode)
 {
 }
 
+static inline void ceph_fscache_invalidate(struct inode *inode, bool dio_write)
+{
+}
+
+static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
+{
+	return NULL;
+}
+
+static inline void ceph_fscache_resize(struct inode *inode, loff_t to)
+{
+}
+
+static inline void ceph_fscache_unpin_writeback(struct inode *inode,
+						struct writeback_control *wbc)
+{
+}
+
+static inline int ceph_fscache_set_page_dirty(struct page *page)
+{
+	return __set_page_dirty_nobuffers(page);
+}
+
 static inline bool ceph_is_cache_enabled(struct inode *inode)
 {
 	return false;
@@ -112,6 +147,10 @@ static inline int ceph_begin_cache_operation(struct netfs_read_request *rreq)
 {
 	return -ENOBUFS;
 }
-#endif
 
-#endif /* _CEPH_CACHE_H */
+static inline void ceph_fscache_note_page_release(struct inode *inode)
+{
+}
+#endif /* CONFIG_CEPH_FSCACHE */
+
+#endif