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, 20 insertions, 14 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index e53c8541f5b2..0ffc4c8d7c10 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -126,7 +126,7 @@ static int ceph_set_page_dirty(struct page *page)
 	BUG_ON(PagePrivate(page));
 	attach_page_private(page, snapc);
 
-	return __set_page_dirty_nobuffers(page);
+	return ceph_fscache_set_page_dirty(page);
 }
 
 /*
@@ -141,8 +141,6 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset,
 	struct ceph_inode_info *ci;
 	struct ceph_snap_context *snapc;
 
-	wait_on_page_fscache(page);
-
 	inode = page->mapping->host;
 	ci = ceph_inode(inode);
 
@@ -153,28 +151,36 @@ static void ceph_invalidatepage(struct page *page, unsigned int offset,
 	}
 
 	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)