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 <[e-mail]>
Signed-off-by: David Howells <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]/ # v1
Link: https://lore.kernel.org/r/[e-mail]/ # v2
Link: https://lore.kernel.org/r/[e-mail]/ # v2
Link: https://lore.kernel.org/r/[e-mail]/ # v3
Link: https://lore.kernel.org/r/[e-mail]/ # v4

fs/ceph/Kconfig

···
 if CEPH_FS
 config CEPH_FSCACHE
 	bool "Enable Ceph client caching support"
-	depends on CEPH_FS=m && FSCACHE_OLD_API || CEPH_FS=y && FSCACHE_OLD_API=y
+	depends on CEPH_FS=m && FSCACHE || CEPH_FS=y && FSCACHE=y
 	help
 	  Choose Y here to enable persistent, read-only local
 	  caching support for Ceph clients using FS-Cache

fs/ceph/addr.c

···
 	BUG_ON(PagePrivate(page));
 	attach_page_private(page, snapc);
 
-	return __set_page_dirty_nobuffers(page);
+	return ceph_fscache_set_page_dirty(page);
 }
 
 /*
···
 	struct ceph_inode_info *ci;
 	struct ceph_snap_context *snapc;
 
-	wait_on_page_fscache(page);
-
 	inode = page->mapping->host;
 	ci = ceph_inode(inode);
 
···
 	}
 
 	WARN_ON(!PageLocked(page));
-	if (!PagePrivate(page))
-		return;
+	if (PagePrivate(page)) {
+		dout("%p invalidatepage %p idx %lu full dirty page\n",
+		     inode, page, page->index);
 
-	dout("%p invalidatepage %p idx %lu full dirty page\n",
-	     inode, page, page->index);
+		snapc = detach_page_private(page);
+		ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
+		ceph_put_snap_context(snapc);
+	}
 
-	snapc = detach_page_private(page);
-	ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
-	ceph_put_snap_context(snapc);
+	wait_on_page_fscache(page);
 }
 
 static int ceph_releasepage(struct page *page, gfp_t gfp)
 {
-	dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
-	     page, page->index, PageDirty(page) ? "" : "not ");
+	struct inode *inode = page->mapping->host;
+
+	dout("%llx:%llx releasepage %p idx %lu (%sdirty)\n",
+	     ceph_vinop(inode), page,
+	     page->index, PageDirty(page) ? "" : "not ");
+
+	if (PagePrivate(page))
+		return 0;
 
 	if (PageFsCache(page)) {
-		if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS))
+		if (!gfpflags_allow_blocking(gfp) || !(gfp & __GFP_FS))
 			return 0;
 		wait_on_page_fscache(page);
 	}
-	return !PagePrivate(page);
+	ceph_fscache_note_page_release(inode);
+	return 1;
 }
 
 static void ceph_netfs_expand_readahead(struct netfs_read_request *rreq)

fs/ceph/cache.c

···
 #include "super.h"
 #include "cache.h"
 
-struct fscache_netfs ceph_cache_netfs = {
-	.name		= "ceph",
-	.version	= 0,
-};
-
-static DEFINE_MUTEX(ceph_fscache_lock);
-static LIST_HEAD(ceph_fscache_list);
-
-struct ceph_fscache_entry {
-	struct list_head list;
-	struct fscache_cookie *fscache;
-	size_t uniq_len;
-	/* The following members must be last */
-	struct ceph_fsid fsid;
-	char uniquifier[];
-};
-
-static const struct fscache_cookie_def ceph_fscache_fsid_object_def = {
-	.name		= "CEPH.fsid",
-	.type		= FSCACHE_COOKIE_TYPE_INDEX,
-};
-
-int __init ceph_fscache_register(void)
+void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
-	return fscache_register_netfs(&ceph_cache_netfs);
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
+
+	/* No caching for filesystem? */
+	if (!fsc->fscache)
+		return;
+
+	/* Regular files only */
+	if (!S_ISREG(inode->i_mode))
+		return;
+
+	/* Only new inodes! */
+	if (!(inode->i_state & I_NEW))
+		return;
+
+	WARN_ON_ONCE(ci->fscache);
+
+	ci->fscache = fscache_acquire_cookie(fsc->fscache, 0,
+					     &ci->i_vino, sizeof(ci->i_vino),
+					     &ci->i_version, sizeof(ci->i_version),
+					     i_size_read(inode));
 }
 
-void ceph_fscache_unregister(void)
+void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
 {
-	fscache_unregister_netfs(&ceph_cache_netfs);
+	struct fscache_cookie *cookie = ci->fscache;
+
+	fscache_relinquish_cookie(cookie, false);
+}
+
+void ceph_fscache_use_cookie(struct inode *inode, bool will_modify)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	fscache_use_cookie(ci->fscache, will_modify);
+}
+
+void ceph_fscache_unuse_cookie(struct inode *inode, bool update)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	if (update) {
+		loff_t i_size = i_size_read(inode);
+
+		fscache_unuse_cookie(ci->fscache, &ci->i_version, &i_size);
+	} else {
+		fscache_unuse_cookie(ci->fscache, NULL, NULL);
+	}
+}
+
+void ceph_fscache_update(struct inode *inode)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	loff_t i_size = i_size_read(inode);
+
+	fscache_update_cookie(ci->fscache, &ci->i_version, &i_size);
+}
+
+void ceph_fscache_invalidate(struct inode *inode, bool dio_write)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	fscache_invalidate(ceph_inode(inode)->fscache,
+			   &ci->i_version, i_size_read(inode),
+			   dio_write ? FSCACHE_INVAL_DIO_WRITE : 0);
 }
 
 int ceph_fscache_register_fs(struct ceph_fs_client* fsc, struct fs_context *fc)
···
 	const struct ceph_fsid *fsid = &fsc->client->fsid;
 	const char *fscache_uniq = fsc->mount_options->fscache_uniq;
 	size_t uniq_len = fscache_uniq ? strlen(fscache_uniq) : 0;
-	struct ceph_fscache_entry *ent;
+	char *name;
 	int err = 0;
 
-	mutex_lock(&ceph_fscache_lock);
-	list_for_each_entry(ent, &ceph_fscache_list, list) {
-		if (memcmp(&ent->fsid, fsid, sizeof(*fsid)))
-			continue;
-		if (ent->uniq_len != uniq_len)
-			continue;
-		if (uniq_len && memcmp(ent->uniquifier, fscache_uniq, uniq_len))
-			continue;
+	name = kasprintf(GFP_KERNEL, "ceph,%pU%s%s", fsid, uniq_len ? "," : "",
+			 uniq_len ? fscache_uniq : "");
+	if (!name)
+		return -ENOMEM;
 
-		errorfc(fc, "fscache cookie already registered for fsid %pU, use fsc=<uniquifier> option",
-		       fsid);
-		err = -EBUSY;
-		goto out_unlock;
+	fsc->fscache = fscache_acquire_volume(name, NULL, NULL, 0);
+	if (IS_ERR_OR_NULL(fsc->fscache)) {
+		errorfc(fc, "Unable to register fscache cookie for %s", name);
+		err = fsc->fscache ? PTR_ERR(fsc->fscache) : -EOPNOTSUPP;
+		fsc->fscache = NULL;
 	}
-
-	ent = kzalloc(sizeof(*ent) + uniq_len, GFP_KERNEL);
-	if (!ent) {
-		err = -ENOMEM;
-		goto out_unlock;
-	}
-
-	memcpy(&ent->fsid, fsid, sizeof(*fsid));
-	if (uniq_len > 0) {
-		memcpy(&ent->uniquifier, fscache_uniq, uniq_len);
-		ent->uniq_len = uniq_len;
-	}
-
-	fsc->fscache = fscache_acquire_cookie(ceph_cache_netfs.primary_index,
-					      &ceph_fscache_fsid_object_def,
-					      &ent->fsid, sizeof(ent->fsid) + uniq_len,
-					      NULL, 0,
-					      fsc, 0, true);
-
-	if (fsc->fscache) {
-		ent->fscache = fsc->fscache;
-		list_add_tail(&ent->list, &ceph_fscache_list);
-	} else {
-		kfree(ent);
-		errorfc(fc, "unable to register fscache cookie for fsid %pU",
-		       fsid);
-		/* all other fs ignore this error */
-	}
-out_unlock:
-	mutex_unlock(&ceph_fscache_lock);
+	kfree(name);
 	return err;
-}
-
-static enum fscache_checkaux ceph_fscache_inode_check_aux(
-	void *cookie_netfs_data, const void *data, uint16_t dlen,
-	loff_t object_size)
-{
-	struct ceph_inode_info* ci = cookie_netfs_data;
-	struct inode* inode = &ci->vfs_inode;
-
-	if (dlen != sizeof(ci->i_version) ||
-	    i_size_read(inode) != object_size)
-		return FSCACHE_CHECKAUX_OBSOLETE;
-
-	if (*(u64 *)data != ci->i_version)
-		return FSCACHE_CHECKAUX_OBSOLETE;
-
-	dout("ceph inode 0x%p cached okay\n", ci);
-	return FSCACHE_CHECKAUX_OKAY;
-}
-
-static const struct fscache_cookie_def ceph_fscache_inode_object_def = {
-	.name		= "CEPH.inode",
-	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
-	.check_aux	= ceph_fscache_inode_check_aux,
-};
-
-void ceph_fscache_register_inode_cookie(struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
-
-	/* No caching for filesystem */
-	if (!fsc->fscache)
-		return;
-
-	/* Only cache for regular files that are read only */
-	if (!S_ISREG(inode->i_mode))
-		return;
-
-	inode_lock_nested(inode, I_MUTEX_CHILD);
-	if (!ci->fscache) {
-		ci->fscache = fscache_acquire_cookie(fsc->fscache,
-						     &ceph_fscache_inode_object_def,
-						     &ci->i_vino, sizeof(ci->i_vino),
-						     &ci->i_version, sizeof(ci->i_version),
-						     ci, i_size_read(inode), false);
-	}
-	inode_unlock(inode);
-}
-
-void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci)
-{
-	struct fscache_cookie* cookie;
-
-	if ((cookie = ci->fscache) == NULL)
-		return;
-
-	ci->fscache = NULL;
-
-	fscache_relinquish_cookie(cookie, &ci->i_vino, false);
-}
-
-static bool ceph_fscache_can_enable(void *data)
-{
-	struct inode *inode = data;
-	return !inode_is_open_for_write(inode);
-}
-
-void ceph_fscache_file_set_cookie(struct inode *inode, struct file *filp)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-
-	if (!fscache_cookie_valid(ci->fscache))
-		return;
-
-	if (inode_is_open_for_write(inode)) {
-		dout("fscache_file_set_cookie %p %p disabling cache\n",
-		     inode, filp);
-		fscache_disable_cookie(ci->fscache, &ci->i_vino, false);
-	} else {
-		fscache_enable_cookie(ci->fscache, &ci->i_vino, i_size_read(inode),
-				      ceph_fscache_can_enable, inode);
-		if (fscache_cookie_enabled(ci->fscache)) {
-			dout("fscache_file_set_cookie %p %p enabling cache\n",
-			     inode, filp);
-		}
-	}
 }
 
 void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc)
 {
-	if (fscache_cookie_valid(fsc->fscache)) {
-		struct ceph_fscache_entry *ent;
-		bool found = false;
-
-		mutex_lock(&ceph_fscache_lock);
-		list_for_each_entry(ent, &ceph_fscache_list, list) {
-			if (ent->fscache == fsc->fscache) {
-				list_del(&ent->list);
-				kfree(ent);
-				found = true;
-				break;
-			}
-		}
-		WARN_ON_ONCE(!found);
-		mutex_unlock(&ceph_fscache_lock);
-
-		__fscache_relinquish_cookie(fsc->fscache, NULL, false);
-	}
-	fsc->fscache = NULL;
+	fscache_relinquish_volume(fsc->fscache, NULL, false);
 }

fs/ceph/cache.h

···
 #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)
 {
···
 	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)));
+}
 
-	if (!cookie)
-		return false;
-	return fscache_cookie_enabled(cookie);
+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);
+
+	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)
 {
···
 {
 }
 
-static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci)
-{
-	return NULL;
-}
-
 static inline void ceph_fscache_register_inode_cookie(struct inode *inode)
 {
 }
···
 {
 }
 
-static inline void ceph_fscache_file_set_cookie(struct inode *inode,
-						struct file *filp)
+static inline void ceph_fscache_use_cookie(struct inode *inode, bool will_modify)
 {
 }
 
-static inline void ceph_fscache_invalidate(struct inode *inode)
+static inline void ceph_fscache_unuse_cookie(struct inode *inode, bool update)
 {
+}
+
+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 -ENOBUFS;
 }
-#endif
 
-#endif /* _CEPH_CACHE_H */
+static inline void ceph_fscache_note_page_release(struct inode *inode)
+{
+}
+#endif /* CONFIG_CEPH_FSCACHE */
+
+#endif

fs/ceph/caps.c

···
 	u32 invalidating_gen = ci->i_rdcache_gen;
 
 	spin_unlock(&ci->i_ceph_lock);
-	ceph_fscache_invalidate(inode);
+	ceph_fscache_invalidate(inode, false);
 	invalidate_mapping_pages(&inode->i_data, 0, -1);
 	spin_lock(&ci->i_ceph_lock);
 
···
 	int wait = (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync);
 
 	dout("write_inode %p wait=%d\n", inode, wait);
+	ceph_fscache_unpin_writeback(inode, wbc);
 	if (wait) {
 		dirty = try_flush_caps(inode, &flush_tid);
 		if (dirty)

fs/ceph/file.c

···
 
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFREG:
-		ceph_fscache_register_inode_cookie(inode);
-		ceph_fscache_file_set_cookie(inode, file);
+		ceph_fscache_use_cookie(inode, file->f_mode & FMODE_WRITE);
 		fallthrough;
 	case S_IFDIR:
 		ret = ceph_init_file_info(inode, file, fmode,
···
 		dout("release inode %p regular file %p\n", inode, file);
 		WARN_ON(!list_empty(&fi->rw_contexts));
 
+		ceph_fscache_unuse_cookie(inode, file->f_mode & FMODE_WRITE);
 		ceph_put_fmode(ci, fi->fmode, 1);
 
 		kmem_cache_free(ceph_file_cachep, fi);
···
 	     snapc, snapc ? snapc->seq : 0);
 
 	if (write) {
-		int ret2 = invalidate_inode_pages2_range(inode->i_mapping,
+		int ret2;
+
+		ceph_fscache_invalidate(inode, true);
+
+		ret2 = invalidate_inode_pages2_range(inode->i_mapping,
 					pos >> PAGE_SHIFT,
 					(pos + count - 1) >> PAGE_SHIFT);
 		if (ret2 < 0)
···
 	if (ret < 0)
 		return ret;
 
+	ceph_fscache_invalidate(inode, false);
 	ret = invalidate_inode_pages2_range(inode->i_mapping,
 					    pos >> PAGE_SHIFT,
 					    (pos + count - 1) >> PAGE_SHIFT);
···
 		goto unlock;
 
 	filemap_invalidate_lock(inode->i_mapping);
+	ceph_fscache_invalidate(inode, false);
 	ceph_zero_pagecache_range(inode, offset, length);
 	ret = ceph_zero_objects(inode, offset, length);
 
···
 		goto out_caps;
 
 	/* Drop dst file cached pages */
+	ceph_fscache_invalidate(dst_inode, false);
 	ret = invalidate_inode_pages2_range(dst_inode->i_mapping,
 					    dst_off >> PAGE_SHIFT,
 					    (dst_off + len) >> PAGE_SHIFT);

fs/ceph/inode.c

···
 	percpu_counter_dec(&mdsc->metric.total_inodes);
 
 	truncate_inode_pages_final(&inode->i_data);
+	if (inode->i_state & I_PINNING_FSCACHE_WB)
+		ceph_fscache_unuse_cookie(inode, true);
 	clear_inode(inode);
 
 	ceph_fscache_unregister_inode_cookie(ci);
···
 		}
 		i_size_write(inode, size);
 		inode->i_blocks = calc_inode_blocks(size);
+		/*
+		 * If we're expanding, then we should be able to just update
+		 * the existing cookie.
+		 */
+		if (size > isize)
+			ceph_fscache_update(inode);
 		ci->i_reported_size = size;
 		if (truncate_seq != ci->i_truncate_seq) {
 			dout("truncate_seq %u -> %u\n",
···
 		     truncate_size);
 		ci->i_truncate_size = truncate_size;
 	}
-
-	if (queue_trunc)
-		ceph_fscache_invalidate(inode);
-
 	return queue_trunc;
 }
 
···
 	}
 
 	spin_unlock(&ci->i_ceph_lock);
+
+	ceph_fscache_register_inode_cookie(inode);
 
 	if (fill_inline)
 		ceph_fill_inline_data(inode, locked_page,
···
 	spin_lock(&ci->i_ceph_lock);
 	dout("set_size %p %llu -> %llu\n", inode, i_size_read(inode), size);
 	i_size_write(inode, size);
+	ceph_fscache_update(inode);
 	inode->i_blocks = calc_inode_blocks(size);
 
 	ret = __ceph_should_report_size(ci);
 
 	spin_unlock(&ci->i_ceph_lock);
+
 	return ret;
 }
 
···
 	u32 orig_gen;
 	int check = 0;
 
+	ceph_fscache_invalidate(inode, false);
+
 	mutex_lock(&ci->i_truncate_mutex);
 
 	if (ceph_inode_is_shutdown(inode)) {
···
 	orig_gen = ci->i_rdcache_gen;
 	spin_unlock(&ci->i_ceph_lock);
 
-	ceph_fscache_invalidate(inode);
+	ceph_fscache_invalidate(inode, false);
 	if (invalidate_inode_pages2(inode->i_mapping) < 0) {
 		pr_err("invalidate_inode_pages2 %llx.%llx failed\n",
 		       ceph_vinop(inode));
···
 	     ci->i_truncate_pending, to);
 	spin_unlock(&ci->i_ceph_lock);
 
+	ceph_fscache_resize(inode, to);
 	truncate_pagecache(inode, to);
 
 	spin_lock(&ci->i_ceph_lock);
···
 
 	if (inode_dirty_flags)
 		__mark_inode_dirty(inode, inode_dirty_flags);
-
 
 	if (mask) {
 		req->r_inode = inode;

fs/ceph/super.c

···
 	if (!ceph_wb_pagevec_pool)
 		goto bad_pagevec_pool;
 
-	error = ceph_fscache_register();
-	if (error)
-		goto bad_fscache;
-
 	return 0;
 
-bad_fscache:
-	kmem_cache_destroy(ceph_mds_request_cachep);
 bad_pagevec_pool:
-	mempool_destroy(ceph_wb_pagevec_pool);
+	kmem_cache_destroy(ceph_mds_request_cachep);
 bad_mds_req:
 	kmem_cache_destroy(ceph_dir_file_cachep);
 bad_dir_file:
···
 	kmem_cache_destroy(ceph_dir_file_cachep);
 	kmem_cache_destroy(ceph_mds_request_cachep);
 	mempool_destroy(ceph_wb_pagevec_pool);
-
-	ceph_fscache_unregister();
 }
 
 static void __ceph_umount_begin(struct ceph_fs_client *fsc)

fs/ceph/super.h

···
 #include <linux/ceph/libceph.h>
 
 #ifdef CONFIG_CEPH_FSCACHE
-#define FSCACHE_USE_NEW_IO_API
 #include <linux/fscache.h>
 #endif
 
···
 #endif
 
 #ifdef CONFIG_CEPH_FSCACHE
-	struct fscache_cookie *fscache;
+	struct fscache_volume *fscache;
 #endif
 };