Merge tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS updates from David Howells:
 "Use the new netfs lib.

  Begin the process of overhauling the use of the fscache API by AFS and
  the introduction of support for features such as Transparent Huge
  Pages (THPs).

   - Add some support for THPs, including using core VM helper functions
     to find details of pages.

   - Use the ITER_XARRAY I/O iterator to mediate access to the pagecache
     as this handles THPs and doesn't require allocation of large bvec
     arrays.

   - Delegate address_space read/pre-write I/O methods for AFS to the
     netfs helper library. A method is provided to the library that
     allows it to issue a read against the server.

     This includes a change in use for PG_fscache (it now indicates a
     DIO write in progress from the marked page), so a number of waits
     need to be deployed for it.

   - Split the core AFS writeback function to make it easier to modify
     in future patches to handle writing to the cache. [This might
     feasibly make more sense moved out into my fscache-iter branch].

  I've tested these with "xfstests -g quick" against an AFS volume
  (xfstests needs patching to make it work). With this, AFS without a
  cache passes all expected xfstests; with a cache, there's an extra
  failure, but that's also there before these patches. Fixing that
  probably requires a greater overhaul (as can be found on my
  fscache-iter branch, but that's for a later time).

  Thanks should go to Marc Dionne and Jeff Altman of AuriStor for
  exercising the patches in their test farm also"

Link: https://lore.kernel.org/lkml/3785063.1619482429@warthog.procyon.org.uk/

* tag 'afs-netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Use the netfs_write_begin() helper
  afs: Use new netfs lib read helper API
  afs: Use the fs operation ops to handle FetchData completion
  afs: Prepare for use of THPs
  afs: Extract writeback extension into its own function
  afs: Wait on PG_fscache before modifying/releasing a page
  afs: Use ITER_XARRAY for writing
  afs: Set up the iov_iter before calling afs_extract_data()
  afs: Log remote unmarshalling errors
  afs: Don't truncate iter during data fetch
  afs: Move key to afs_read struct
  afs: Print the operation debug_id when logging an unexpected data version
  afs: Pass page into dirty region helpers to provide THP size
  afs: Disable use of the fscache I/O routines

2 files changed, 33 insertions, 43 deletions

diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index f6abcc0bbd6e..cee5f83c0f11 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -53,7 +53,7 @@ int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
 			   struct msghdr *, size_t,
 			   rxrpc_notify_end_tx_t);
 int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
-			   struct iov_iter *, bool, u32 *, u16 *);
+			   struct iov_iter *, size_t *, bool, u32 *, u16 *);
 bool rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *,
 			     u32, int, const char *);
 void rxrpc_kernel_end_call(struct socket *, struct rxrpc_call *);
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 4a5cc8c64be3..3ccf591b2374 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -886,65 +886,52 @@ TRACE_EVENT(afs_call_done,
 		      __entry->rx_call)
 	    );
 
-TRACE_EVENT(afs_send_pages,
-	    TP_PROTO(struct afs_call *call, struct msghdr *msg,
-		     pgoff_t first, pgoff_t last, unsigned int offset),
+TRACE_EVENT(afs_send_data,
+	    TP_PROTO(struct afs_call *call, struct msghdr *msg),
 
-	    TP_ARGS(call, msg, first, last, offset),
+	    TP_ARGS(call, msg),
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,		call		)
-		    __field(pgoff_t,			first		)
-		    __field(pgoff_t,			last		)
-		    __field(unsigned int,		nr		)
-		    __field(unsigned int,		bytes		)
-		    __field(unsigned int,		offset		)
 		    __field(unsigned int,		flags		)
+		    __field(loff_t,			offset		)
+		    __field(loff_t,			count		)
 			     ),
 
 	    TP_fast_assign(
 		    __entry->call = call->debug_id;
-		    __entry->first = first;
-		    __entry->last = last;
-		    __entry->nr = msg->msg_iter.nr_segs;
-		    __entry->bytes = msg->msg_iter.count;
-		    __entry->offset = offset;
 		    __entry->flags = msg->msg_flags;
+		    __entry->offset = msg->msg_iter.xarray_start + msg->msg_iter.iov_offset;
+		    __entry->count = iov_iter_count(&msg->msg_iter);
 			   ),
 
-	    TP_printk(" c=%08x %lx-%lx-%lx b=%x o=%x f=%x",
-		      __entry->call,
-		      __entry->first, __entry->first + __entry->nr - 1, __entry->last,
-		      __entry->bytes, __entry->offset,
+	    TP_printk(" c=%08x o=%llx n=%llx f=%x",
+		      __entry->call, __entry->offset, __entry->count,
 		      __entry->flags)
 	    );
 
-TRACE_EVENT(afs_sent_pages,
-	    TP_PROTO(struct afs_call *call, pgoff_t first, pgoff_t last,
-		     pgoff_t cursor, int ret),
+TRACE_EVENT(afs_sent_data,
+	    TP_PROTO(struct afs_call *call, struct msghdr *msg, int ret),
 
-	    TP_ARGS(call, first, last, cursor, ret),
+	    TP_ARGS(call, msg, ret),
 
 	    TP_STRUCT__entry(
 		    __field(unsigned int,		call		)
-		    __field(pgoff_t,			first		)
-		    __field(pgoff_t,			last		)
-		    __field(pgoff_t,			cursor		)
 		    __field(int,			ret		)
+		    __field(loff_t,			offset		)
+		    __field(loff_t,			count		)
 			     ),
 
 	    TP_fast_assign(
 		    __entry->call = call->debug_id;
-		    __entry->first = first;
-		    __entry->last = last;
-		    __entry->cursor = cursor;
 		    __entry->ret = ret;
+		    __entry->offset = msg->msg_iter.xarray_start + msg->msg_iter.iov_offset;
+		    __entry->count = iov_iter_count(&msg->msg_iter);
 			   ),
 
-	    TP_printk(" c=%08x %lx-%lx c=%lx r=%d",
-		      __entry->call,
-		      __entry->first, __entry->last,
-		      __entry->cursor, __entry->ret)
+	    TP_printk(" c=%08x o=%llx n=%llx r=%x",
+		      __entry->call, __entry->offset, __entry->count,
+		      __entry->ret)
 	    );
 
 TRACE_EVENT(afs_dir_check_failed,
@@ -969,30 +956,33 @@ TRACE_EVENT(afs_dir_check_failed,
 	    );
 
 TRACE_EVENT(afs_page_dirty,
-	    TP_PROTO(struct afs_vnode *vnode, const char *where,
-		     pgoff_t page, unsigned long priv),
+	    TP_PROTO(struct afs_vnode *vnode, const char *where, struct page *page),
 
-	    TP_ARGS(vnode, where, page, priv),
+	    TP_ARGS(vnode, where, page),
 
 	    TP_STRUCT__entry(
 		    __field(struct afs_vnode *,		vnode		)
 		    __field(const char *,		where		)
 		    __field(pgoff_t,			page		)
-		    __field(unsigned long,		priv		)
+		    __field(unsigned long,		from		)
+		    __field(unsigned long,		to		)
 			     ),
 
 	    TP_fast_assign(
 		    __entry->vnode = vnode;
 		    __entry->where = where;
-		    __entry->page = page;
-		    __entry->priv = priv;
+		    __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);
 			   ),
 
-	    TP_printk("vn=%p %lx %s %zx-%zx%s",
+	    TP_printk("vn=%p %lx %s %lx-%lx%s",
 		      __entry->vnode, __entry->page, __entry->where,
-		      afs_page_dirty_from(__entry->priv),
-		      afs_page_dirty_to(__entry->priv),
-		      afs_is_page_dirty_mmapped(__entry->priv) ? " M" : "")
+		      __entry->from,
+		      __entry->to & ~(1UL << (BITS_PER_LONG - 1)),
+		      __entry->to & (1UL << (BITS_PER_LONG - 1)) ? " M" : "")
 	    );
 
 TRACE_EVENT(afs_call_state,