netfs, 9p, afs, ceph: Use folios

Convert the netfs helper library to use folios throughout, convert the 9p
and afs filesystems to use folios in their file I/O paths and convert the
ceph filesystem to use just enough folios to compile.

With these changes, afs passes -g quick xfstests.

Changes
=======
ver #5:
 - Got rid of folio_end{io,_read,_write}() and inlined the stuff it does
   instead (Willy decided he didn't want this after all).

ver #4:
 - Fixed a bug in afs_redirty_page() whereby it didn't set the next page
   index in the loop and returned too early.
 - Simplified a check in v9fs_vfs_write_folio_locked()[1].
 - Undid a change to afs_symlink_readpage()[1].
 - Used offset_in_folio() in afs_write_end()[1].
 - Changed from using page_endio() to folio_end{io,_read,_write}()[1].

ver #2:
 - Add 9p foliation.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: kafs-testing@auristor.com
cc: Matthew Wilcox (Oracle) <willy@infradead.org>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/YYKa3bfQZxK5/wDN@casper.infradead.org/ [1]
Link: https://lore.kernel.org/r/2408234.1628687271@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/162877311459.3085614.10601478228012245108.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/162981153551.1901565.3124454657133703341.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163005745264.2472992.9852048135392188995.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163584187452.4023316.500389675405550116.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/163649328026.309189.1124218109373941936.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/163657852454.834781.9265101983152100556.stgit@warthog.procyon.org.uk/ # v5

2 files changed, 17 insertions, 16 deletions

diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 12c4177f7703..ca0683b9e3d1 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -166,13 +166,13 @@ struct netfs_read_request {
 	short			error;		/* 0 or error that occurred */
 	loff_t			i_size;		/* Size of the file */
 	loff_t			start;		/* Start position */
-	pgoff_t			no_unlock_page;	/* Don't unlock this page after read */
+	pgoff_t			no_unlock_folio; /* Don't unlock this folio after read */
 	refcount_t		usage;
 	unsigned long		flags;
 #define NETFS_RREQ_INCOMPLETE_IO	0	/* Some ioreqs terminated short or with error */
 #define NETFS_RREQ_WRITE_TO_CACHE	1	/* Need to write to the cache */
-#define NETFS_RREQ_NO_UNLOCK_PAGE	2	/* Don't unlock no_unlock_page on completion */
-#define NETFS_RREQ_DONT_UNLOCK_PAGES	3	/* Don't unlock the pages on completion */
+#define NETFS_RREQ_NO_UNLOCK_FOLIO	2	/* Don't unlock no_unlock_folio on completion */
+#define NETFS_RREQ_DONT_UNLOCK_FOLIOS	3	/* Don't unlock the folios on completion */
 #define NETFS_RREQ_FAILED		4	/* The request failed */
 #define NETFS_RREQ_IN_PROGRESS		5	/* Unlocked when the request completes */
 	const struct netfs_read_request_ops *netfs_ops;
@@ -190,7 +190,7 @@ struct netfs_read_request_ops {
 	void (*issue_op)(struct netfs_read_subrequest *subreq);
 	bool (*is_still_valid)(struct netfs_read_request *rreq);
 	int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
-				 struct page *page, void **_fsdata);
+				 struct folio *folio, void **_fsdata);
 	void (*done)(struct netfs_read_request *rreq);
 	void (*cleanup)(struct address_space *mapping, void *netfs_priv);
 };
@@ -240,11 +240,11 @@ extern void netfs_readahead(struct readahead_control *,
 			    const struct netfs_read_request_ops *,
 			    void *);
 extern int netfs_readpage(struct file *,
-			  struct page *,
+			  struct folio *,
 			  const struct netfs_read_request_ops *,
 			  void *);
 extern int netfs_write_begin(struct file *, struct address_space *,
-			     loff_t, unsigned int, unsigned int, struct page **,
+			     loff_t, unsigned int, unsigned int, struct folio **,
 			     void **,
 			     const struct netfs_read_request_ops *,
 			     void *);
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index bca73e8c8cde..499f5fabd20f 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -1016,31 +1016,32 @@ TRACE_EVENT(afs_dir_check_failed,
 		      __entry->vnode, __entry->off, __entry->i_size)
 	    );
 
-TRACE_EVENT(afs_page_dirty,
-	    TP_PROTO(struct afs_vnode *vnode, const char *where, struct page *page),
+TRACE_EVENT(afs_folio_dirty,
+	    TP_PROTO(struct afs_vnode *vnode, const char *where, struct folio *folio),
 
-	    TP_ARGS(vnode, where, page),
+	    TP_ARGS(vnode, where, folio),
 
 	    TP_STRUCT__entry(
 		    __field(struct afs_vnode *,		vnode		)
 		    __field(const char *,		where		)
-		    __field(pgoff_t,			page		)
+		    __field(pgoff_t,			index		)
 		    __field(unsigned long,		from		)
 		    __field(unsigned long,		to		)
 			     ),
 
 	    TP_fast_assign(
+		    unsigned long priv = (unsigned long)folio_get_private(folio);
 		    __entry->vnode = vnode;
 		    __entry->where = where;
-		    __entry->page = page->index;
-		    __entry->from = afs_page_dirty_from(page, page->private);
-		    __entry->to = afs_page_dirty_to(page, page->private);
-		    __entry->to |= (afs_is_page_dirty_mmapped(page->private) ?
-				    (1UL << (BITS_PER_LONG - 1)) : 0);
+		    __entry->index = folio_index(folio);
+		    __entry->from  = afs_folio_dirty_from(folio, priv);
+		    __entry->to    = afs_folio_dirty_to(folio, priv);
+		    __entry->to   |= (afs_is_folio_dirty_mmapped(priv) ?
+				      (1UL << (BITS_PER_LONG - 1)) : 0);
 			   ),
 
 	    TP_printk("vn=%p %lx %s %lx-%lx%s",
-		      __entry->vnode, __entry->page, __entry->where,
+		      __entry->vnode, __entry->index, __entry->where,
 		      __entry->from,
 		      __entry->to & ~(1UL << (BITS_PER_LONG - 1)),
 		      __entry->to & (1UL << (BITS_PER_LONG - 1)) ? " M" : "")