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* [PATCH 00/10] iov_iter: Add new iters and use with AFS
@ 2018-08-06 13:16 David Howells
  2018-08-06 13:16 ` [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions David Howells
                   ` (9 more replies)
  0 siblings, 10 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:16 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew


Hi Al,

Here's a set of patches that adds two new iov_iter types and then makes AFS
use them to do I/O.  The iov_iter changes are:

 (1) Separate the type from the direction in the iov_iter struct and
     provide accessor functions to wrap type checking.

 (2) Renumber the type constants to be contiguous small unsigned integers,
     starting from 0 and then use switch-statements rather than if-else
     chains using bit-testing.

     Note that the compiler can optimise this better by using CMP rather
     than AND/TEST, say, as comparing integers requires fewer CMP
     instructions or can use jump tables.

 (3) Change count and iov_offset from size_t to loff_t.  This allows
     iov_offset to be then used as a byte offset with ITER_MAPPING and
     allows 4GiB and larger reads and writes to be proposed.

     This makes no difference on a 64-bit system, but does make a 32-bit
     compilation a bit larger.  Possibly only iov_offset really needs to be
     made loff_t and size >= 4GiB should just be disallowed on 32-bit.

 (4) Add an ITER_MAPPING iterator type.  This provides an iterator that
     directly accesses an address_space, and assumes that the target pages
     are in some way locked (eg. PG_lock or PG_writeback).

 (5) Add an ITER_DISCARD iterator type.  This provides an iterator that
     simply discards anything written to it.  It cannot be used as a data
     source.

The afs changes are:

 (1) Use a single ITER_MAPPING iterator to cover all the data read by a
     single FetchData RPC op.  This involves switching the operation to an
     ITER_KVEC iterator to read the status record that's transmitted after
     the data.

 (2) Use an ITER_DISCARD iterator to discard any extra data the server may
     have included that we don't want.

 (3) Use a single ITER_MAPPING iterator to cover all the data written by a
     single StoreData RPC op.

 (4) Add synchronous O_DIRECT read support.

The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=afs-next

David
---
David Howells (10):
      iov_iter: Separate type from direction and use accessor functions
      iov_iter: Renumber the ITER_* constants in uio.h
      iov_iter: Make count and iov_offset loff_t not size_t
      iov_iter: Add mapping and discard iterator types
      afs: Better tracing of protocol errors
      afs: Set up the iov_iter before calling afs_extract_data()
      afs: Use ITER_MAPPING for writing
      afs: Add O_DIRECT read support
      afs: Add a couple of tracepoints to log I/O errors
      afs: Don't invoke the server to read data beyond EOF


 block/bio.c                              |    2 
 drivers/block/drbd/drbd_main.c           |    2 
 drivers/block/drbd/drbd_receiver.c       |    2 
 drivers/block/loop.c                     |    9 
 drivers/block/nbd.c                      |   12 -
 drivers/isdn/mISDN/l1oip_core.c          |    3 
 drivers/misc/vmw_vmci/vmci_queue_pair.c  |    6 
 drivers/nvme/target/io-cmd-file.c        |    2 
 drivers/target/iscsi/iscsi_target_util.c |    6 
 drivers/target/target_core_file.c        |    6 
 drivers/usb/usbip/usbip_common.c         |    2 
 drivers/xen/pvcalls-back.c               |    8 
 fs/9p/vfs_addr.c                         |    4 
 fs/9p/vfs_dir.c                          |    2 
 fs/9p/vfs_file.c                         |    2 
 fs/9p/xattr.c                            |    4 
 fs/afs/cmservice.c                       |   56 +--
 fs/afs/dir.c                             |  210 ++++++++---
 fs/afs/file.c                            |  263 ++++++++++----
 fs/afs/fsclient.c                        |  409 ++++++++-------------
 fs/afs/inode.c                           |    2 
 fs/afs/internal.h                        |   81 +++-
 fs/afs/mntpt.c                           |    2 
 fs/afs/rxrpc.c                           |  156 ++------
 fs/afs/server.c                          |    4 
 fs/afs/vlclient.c                        |  134 +++----
 fs/afs/volume.c                          |    2 
 fs/afs/write.c                           |  112 ++++--
 fs/block_dev.c                           |    2 
 fs/btrfs/file.c                          |    7 
 fs/ceph/file.c                           |    7 
 fs/cifs/connect.c                        |    4 
 fs/cifs/file.c                           |    4 
 fs/cifs/misc.c                           |    4 
 fs/cifs/smb2ops.c                        |    4 
 fs/cifs/smbdirect.c                      |   17 +
 fs/cifs/transport.c                      |    8 
 fs/direct-io.c                           |    2 
 fs/dlm/lowcomms.c                        |    2 
 fs/fuse/file.c                           |    2 
 fs/iomap.c                               |    2 
 fs/nfs/direct.c                          |    2 
 fs/nfs/file.c                            |    4 
 fs/nfsd/vfs.c                            |    4 
 fs/ocfs2/cluster/tcp.c                   |    2 
 fs/orangefs/inode.c                      |    2 
 fs/splice.c                              |    7 
 include/linux/fscache.h                  |   31 ++
 include/linux/uio.h                      |   71 ++--
 include/trace/events/afs.h               |  202 ++++++++---
 lib/iov_iter.c                           |  572 ++++++++++++++++++++++++------
 mm/filemap.c                             |    2 
 mm/page_io.c                             |    2 
 net/9p/client.c                          |    4 
 net/9p/trans_virtio.c                    |    2 
 net/bluetooth/6lowpan.c                  |    2 
 net/bluetooth/a2mp.c                     |    2 
 net/bluetooth/smp.c                      |    2 
 net/ceph/messenger.c                     |    6 
 net/netfilter/ipvs/ip_vs_sync.c          |    2 
 net/rxrpc/recvmsg.c                      |    4 
 net/smc/smc_clc.c                        |    4 
 net/socket.c                             |    6 
 net/sunrpc/svcsock.c                     |    2 
 net/tipc/topsrv.c                        |    2 
 net/tls/tls_device.c                     |    4 
 net/tls/tls_sw.c                         |    4 
 67 files changed, 1555 insertions(+), 960 deletions(-)

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
@ 2018-08-06 13:16 ` David Howells
  2018-08-06 13:16 ` [PATCH 02/10] iov_iter: Renumber the ITER_* constants in uio.h David Howells
                   ` (8 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:16 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 block/bio.c                              |    2 
 drivers/block/drbd/drbd_main.c           |    2 
 drivers/block/drbd/drbd_receiver.c       |    2 
 drivers/block/loop.c                     |    9 +-
 drivers/block/nbd.c                      |   12 +-
 drivers/isdn/mISDN/l1oip_core.c          |    3 -
 drivers/misc/vmw_vmci/vmci_queue_pair.c  |    6 +
 drivers/nvme/target/io-cmd-file.c        |    2 
 drivers/target/iscsi/iscsi_target_util.c |    6 -
 drivers/target/target_core_file.c        |    6 +
 drivers/usb/usbip/usbip_common.c         |    2 
 drivers/xen/pvcalls-back.c               |    8 +-
 fs/9p/vfs_addr.c                         |    4 -
 fs/9p/vfs_dir.c                          |    2 
 fs/9p/xattr.c                            |    4 -
 fs/afs/rxrpc.c                           |   15 +--
 fs/block_dev.c                           |    2 
 fs/ceph/file.c                           |    7 +
 fs/cifs/connect.c                        |    4 -
 fs/cifs/file.c                           |    4 -
 fs/cifs/misc.c                           |    4 -
 fs/cifs/smb2ops.c                        |    4 -
 fs/cifs/smbdirect.c                      |   17 +++
 fs/cifs/transport.c                      |    8 +-
 fs/direct-io.c                           |    2 
 fs/dlm/lowcomms.c                        |    2 
 fs/fuse/file.c                           |    2 
 fs/iomap.c                               |    2 
 fs/nfsd/vfs.c                            |    4 -
 fs/ocfs2/cluster/tcp.c                   |    2 
 fs/orangefs/inode.c                      |    2 
 fs/splice.c                              |    7 +
 include/linux/uio.h                      |   49 ++++++----
 lib/iov_iter.c                           |  154 ++++++++++++++++++------------
 mm/filemap.c                             |    2 
 mm/page_io.c                             |    2 
 net/9p/client.c                          |    2 
 net/9p/trans_virtio.c                    |    2 
 net/bluetooth/6lowpan.c                  |    2 
 net/bluetooth/a2mp.c                     |    2 
 net/bluetooth/smp.c                      |    2 
 net/ceph/messenger.c                     |    6 +
 net/netfilter/ipvs/ip_vs_sync.c          |    2 
 net/smc/smc_clc.c                        |    4 -
 net/socket.c                             |    6 +
 net/sunrpc/svcsock.c                     |    2 
 net/tipc/topsrv.c                        |    2 
 net/tls/tls_device.c                     |    4 -
 net/tls/tls_sw.c                         |    4 -
 49 files changed, 223 insertions(+), 182 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 047c5dca6d90..df999480c0f4 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1330,7 +1330,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 	/*
 	 * success
 	 */
-	if (((iter->type & WRITE) && (!map_data || !map_data->null_mapped)) ||
+	if ((iov_iter_rw(iter) == WRITE && (!map_data || !map_data->null_mapped)) ||
 	    (map_data && map_data->from_user)) {
 		ret = bio_copy_from_iter(bio, iter);
 		if (ret)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index a80809bd3057..53d840ab1df2 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1856,7 +1856,7 @@ int drbd_send(struct drbd_connection *connection, struct socket *sock,
 
 	/* THINK  if (signal_pending) return ... ? */
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size);
 
 	if (sock == connection->data.socket) {
 		rcu_read_lock();
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index be9450f5ad1c..d1b05e124325 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -516,7 +516,7 @@ static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flag
 	struct msghdr msg = {
 		.msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
 	};
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
 	return sock_recvmsg(sock, &msg, msg.msg_flags);
 }
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 4cb1d1be3cfb..13598884a787 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -268,7 +268,7 @@ static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos)
 	struct iov_iter i;
 	ssize_t bw;
 
-	iov_iter_bvec(&i, ITER_BVEC | WRITE, bvec, 1, bvec->bv_len);
+	iov_iter_bvec(&i, WRITE, bvec, 1, bvec->bv_len);
 
 	file_start_write(file);
 	bw = vfs_iter_write(file, &i, ppos, 0);
@@ -346,7 +346,7 @@ static int lo_read_simple(struct loop_device *lo, struct request *rq,
 	ssize_t len;
 
 	rq_for_each_segment(bvec, rq, iter) {
-		iov_iter_bvec(&i, ITER_BVEC, &bvec, 1, bvec.bv_len);
+		iov_iter_bvec(&i, READ, &bvec, 1, bvec.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0)
 			return len;
@@ -387,7 +387,7 @@ static int lo_read_transfer(struct loop_device *lo, struct request *rq,
 		b.bv_offset = 0;
 		b.bv_len = bvec.bv_len;
 
-		iov_iter_bvec(&i, ITER_BVEC, &b, 1, b.bv_len);
+		iov_iter_bvec(&i, READ, &b, 1, b.bv_len);
 		len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0);
 		if (len < 0) {
 			ret = len;
@@ -554,8 +554,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
 	}
 	atomic_set(&cmd->ref, 2);
 
-	iov_iter_bvec(&iter, ITER_BVEC | rw, bvec,
-		      segments, blk_rq_bytes(rq));
+	iov_iter_bvec(&iter, rw, bvec, segments, blk_rq_bytes(rq));
 	iter.iov_offset = offset;
 
 	cmd->iocb.ki_pos = pos;
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 3863c00372bb..3e5fb3decdce 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -473,7 +473,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
 	u32 nbd_cmd_flags = 0;
 	int sent = nsock->sent, skip = 0;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
+	iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
 
 	switch (req_op(req)) {
 	case REQ_OP_DISCARD:
@@ -564,8 +564,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
 
 			dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
 				req, bvec.bv_len);
-			iov_iter_bvec(&from, ITER_BVEC | WRITE,
-				      &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&from, WRITE, &bvec, 1, bvec.bv_len);
 			if (skip) {
 				if (skip >= iov_iter_count(&from)) {
 					skip -= iov_iter_count(&from);
@@ -624,7 +623,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 	int ret = 0;
 
 	reply.magic = 0;
-	iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply));
+	iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
 	result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
 	if (result <= 0) {
 		if (!nbd_disconnected(config))
@@ -678,8 +677,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 		struct bio_vec bvec;
 
 		rq_for_each_segment(bvec, req, iter) {
-			iov_iter_bvec(&to, ITER_BVEC | READ,
-				      &bvec, 1, bvec.bv_len);
+			iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len);
 			result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
 			if (result <= 0) {
 				dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
@@ -1073,7 +1071,7 @@ static void send_disconnects(struct nbd_device *nbd)
 	for (i = 0; i < config->num_connections; i++) {
 		struct nbd_sock *nsock = config->socks[i];
 
-		iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request));
+		iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
 		mutex_lock(&nsock->tx_lock);
 		ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
 		if (ret <= 0)
diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index b05022f94f18..072bb5e36c18 100644
--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -718,8 +718,7 @@ l1oip_socket_thread(void *data)
 		printk(KERN_DEBUG "%s: socket created and open\n",
 		       __func__);
 	while (!signal_pending(current)) {
-		iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1,
-				recvbuf_size);
+		iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, recvbuf_size);
 		recvlen = sock_recvmsg(socket, &msg, 0);
 		if (recvlen > 0) {
 			l1oip_socket_parse(hc, &sin_rx, recvbuf, recvlen);
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index b4d7774cfe07..a7fb26246385 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -3035,7 +3035,7 @@ ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&from, WRITE, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
@@ -3079,7 +3079,7 @@ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&to, READ, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
@@ -3124,7 +3124,7 @@ ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+	iov_iter_kvec(&to, READ, &v, 1, buf_size);
 
 	qp_lock(qpair);
 
diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 8c42b3a8c420..ba05278b21b2 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -96,7 +96,7 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
 		rw = READ;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
+	iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
 
 	iocb->ki_pos = pos;
 	iocb->ki_filp = req->ns->file;
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 4435bf374d2d..c86039c0fbc1 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -1249,8 +1249,7 @@ static int iscsit_do_rx_data(
 		return -1;
 
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
-		      count->iov, count->iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, READ, count->iov, count->iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
@@ -1306,8 +1305,7 @@ int tx_data(
 
 	memset(&msg, 0, sizeof(struct msghdr));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
-		      iov, iov_count, data);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, iov_count, data);
 
 	while (msg_data_left(&msg)) {
 		int tx_loop = sock_sendmsg(conn->sock, &msg);
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 16751ae55d7b..49b110d1b972 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -303,7 +303,7 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 		len += sg->length;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC | is_write, bvec, sgl_nents, len);
+	iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
 
 	aio_cmd->cmd = cmd;
 	aio_cmd->len = len;
@@ -353,7 +353,7 @@ static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 		len += sg->length;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
+	iov_iter_bvec(&iter, READ, bvec, sgl_nents, len);
 	if (is_write)
 		ret = vfs_iter_write(fd, &iter, &pos, 0);
 	else
@@ -490,7 +490,7 @@ fd_execute_write_same(struct se_cmd *cmd)
 		len += se_dev->dev_attrib.block_size;
 	}
 
-	iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
+	iov_iter_bvec(&iter, READ, bvec, nolb, len);
 	ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos, 0);
 
 	kfree(bvec);
diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c
index 9756752c0681..45da3e01c7b0 100644
--- a/drivers/usb/usbip/usbip_common.c
+++ b/drivers/usb/usbip/usbip_common.c
@@ -309,7 +309,7 @@ int usbip_recv(struct socket *sock, void *buf, int size)
 	if (!sock || !buf || !size)
 		return -EINVAL;
 
-	iov_iter_kvec(&msg.msg_iter, READ|ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, size);
 
 	usbip_dbg_xmit("enter\n");
 
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index b1092fbefa63..2e5d845b5091 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -137,13 +137,13 @@ static void pvcalls_conn_back_read(void *opaque)
 	if (masked_prod < masked_cons) {
 		vec[0].iov_base = data->in + masked_prod;
 		vec[0].iov_len = wanted;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 1, wanted);
+		iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted);
 	} else {
 		vec[0].iov_base = data->in + masked_prod;
 		vec[0].iov_len = array_size - masked_prod;
 		vec[1].iov_base = data->in;
 		vec[1].iov_len = wanted - vec[0].iov_len;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 2, wanted);
+		iov_iter_kvec(&msg.msg_iter, WRITE, vec, 2, wanted);
 	}
 
 	atomic_set(&map->read, 0);
@@ -195,13 +195,13 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
 	if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) {
 		vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
 		vec[0].iov_len = size;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 1, size);
+		iov_iter_kvec(&msg.msg_iter, READ, vec, 1, size);
 	} else {
 		vec[0].iov_base = data->out + pvcalls_mask(cons, array_size);
 		vec[0].iov_len = array_size - pvcalls_mask(cons, array_size);
 		vec[1].iov_base = data->out;
 		vec[1].iov_len = size - vec[0].iov_len;
-		iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 2, size);
+		iov_iter_kvec(&msg.msg_iter, READ, vec, 2, size);
 	}
 
 	atomic_set(&map->write, 0);
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index e1cbdfdb7c68..0bcbcc20f769 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -65,7 +65,7 @@ static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
 	if (retval == 0)
 		return retval;
 
-	iov_iter_bvec(&to, ITER_BVEC | READ, &bvec, 1, PAGE_SIZE);
+	iov_iter_bvec(&to, READ, &bvec, 1, PAGE_SIZE);
 
 	retval = p9_client_read(fid, page_offset(page), &to, &err);
 	if (err) {
@@ -175,7 +175,7 @@ static int v9fs_vfs_writepage_locked(struct page *page)
 	bvec.bv_page = page;
 	bvec.bv_offset = 0;
 	bvec.bv_len = len;
-	iov_iter_bvec(&from, ITER_BVEC | WRITE, &bvec, 1, len);
+	iov_iter_bvec(&from, WRITE, &bvec, 1, len);
 
 	/* We should have writeback_fid always set */
 	BUG_ON(!v9inode->writeback_fid);
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index b0405d6aac85..d5db3c968a03 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -133,7 +133,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 		if (rdir->tail == rdir->head) {
 			struct iov_iter to;
 			int n;
-			iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
+			iov_iter_kvec(&to, READ, &kvec, 1, buflen);
 			n = p9_client_read(file->private_data, ctx->pos, &to,
 					   &err);
 			if (err)
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index f329eee6dc93..92ed5ecfafd1 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -32,7 +32,7 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
 	struct iov_iter to;
 	int err;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size);
+	iov_iter_kvec(&to, READ, &kvec, 1, buffer_size);
 
 	attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
 	if (IS_ERR(attr_fid)) {
@@ -107,7 +107,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
 	struct iov_iter from;
 	int retval;
 
-	iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len);
+	iov_iter_kvec(&from, WRITE, &kvec, 1, value_len);
 
 	p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n",
 		 name, value_len, flags);
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 19db5f672a9d..55441af2de53 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -286,7 +286,7 @@ static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 		offset = 0;
 	}
 
-	iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
+	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
 }
 
 /*
@@ -401,8 +401,7 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
-		      call->request_size);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
@@ -432,7 +431,7 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
 					RX_USER_ABORT, ret, "KSD");
 	} else {
-		iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, NULL, 0, 0);
+		iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
 				       &msg.msg_iter, false,
 				       &call->abort_code, &call->service_id);
@@ -468,7 +467,7 @@ static void afs_deliver_to_call(struct afs_call *call)
 		if (state == AFS_CALL_SV_AWAIT_ACK) {
 			struct iov_iter iter;
 
-			iov_iter_kvec(&iter, READ | ITER_KVEC, NULL, 0, 0);
+			iov_iter_kvec(&iter, READ, NULL, 0, 0);
 			ret = rxrpc_kernel_recv_data(call->net->socket,
 						     call->rxcall, &iter, false,
 						     &remote_abort,
@@ -827,7 +826,7 @@ void afs_send_empty_reply(struct afs_call *call)
 
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+	iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;
@@ -866,7 +865,7 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 	iov[0].iov_len		= len;
 	msg.msg_name		= NULL;
 	msg.msg_namelen		= 0;
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
 	msg.msg_flags		= 0;
@@ -907,7 +906,7 @@ int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 
 	iov.iov_base = buf + call->offset;
 	iov.iov_len = count - call->offset;
-	iov_iter_kvec(&iter, ITER_KVEC | READ, &iov, 1, count - call->offset);
+	iov_iter_kvec(&iter, READ, &iov, 1, count - call->offset);
 
 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, &iter,
 				     want_more, &remote_abort,
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7dc135204722..aa54c91df73e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -349,7 +349,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 
 	dio->size = 0;
 	dio->multi_bio = false;
-	dio->should_dirty = is_read && (iter->type == ITER_IOVEC);
+	dio->should_dirty = is_read && iter_is_iovec(iter);
 
 	blk_start_plug(&plug);
 	for (;;) {
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ad0bed99b1d5..f0ddb0dc4f16 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -659,7 +659,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
 	if (ret < 0)
 		return ret;
 
-	if (unlikely(to->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(to))) {
 		size_t page_off;
 		ret = iov_iter_get_pages_alloc(to, &pages, len,
 					       &page_off);
@@ -822,7 +822,7 @@ static void ceph_aio_complete_req(struct ceph_osd_request *req)
 				aio_req->total_len = rc + zlen;
 			}
 
-			iov_iter_bvec(&i, ITER_BVEC, osd_data->bvec_pos.bvecs,
+			iov_iter_bvec(&i, READ, osd_data->bvec_pos.bvecs,
 				      osd_data->num_bvecs,
 				      osd_data->bvec_pos.iter.bi_size);
 			iov_iter_advance(&i, rc);
@@ -1045,8 +1045,7 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 				int zlen = min_t(size_t, len - ret,
 						 size - pos - ret);
 
-				iov_iter_bvec(&i, ITER_BVEC, bvecs, num_pages,
-					      len);
+				iov_iter_bvec(&i, READ, bvecs, num_pages, len);
 				iov_iter_advance(&i, ret);
 				iov_iter_zero(zlen, &i);
 				ret += zlen;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 5df2c0698cda..b3feb2c6db5b 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -589,7 +589,7 @@ cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 {
 	struct msghdr smb_msg;
 	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
-	iov_iter_kvec(&smb_msg.msg_iter, READ | ITER_KVEC, &iov, 1, to_read);
+	iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 
 	return cifs_readv_from_socket(server, &smb_msg);
 }
@@ -601,7 +601,7 @@ cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 	struct msghdr smb_msg;
 	struct bio_vec bv = {
 		.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
-	iov_iter_bvec(&smb_msg.msg_iter, READ | ITER_BVEC, &bv, 1, to_read);
+	iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 	return cifs_readv_from_socket(server, &smb_msg);
 }
 
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8d41ca7bfcf1..dcdbcb6f09f8 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2990,7 +2990,7 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
 		size_t copy = min_t(size_t, remaining, PAGE_SIZE);
 		size_t written;
 
-		if (unlikely(iter->type & ITER_PIPE)) {
+		if (unlikely(iov_iter_is_pipe(iter))) {
 			void *addr = kmap_atomic(page);
 
 			written = copy_to_iter(addr, copy, iter);
@@ -3302,7 +3302,7 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
 	if (!is_sync_kiocb(iocb))
 		ctx->iocb = iocb;
 
-	if (to->type == ITER_IOVEC)
+	if (iter_is_iovec(to))
 		ctx->should_dirty = true;
 
 	rc = setup_aio_ctx_iter(ctx, to, READ);
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 53e8362cbc4a..65540d33993e 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -780,7 +780,7 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 	struct page **pages = NULL;
 	struct bio_vec *bv = NULL;
 
-	if (iter->type & ITER_KVEC) {
+	if (iov_iter_type(iter) == ITER_KVEC) {
 		memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
 		ctx->len = count;
 		iov_iter_advance(iter, count);
@@ -851,7 +851,7 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
 	ctx->bv = bv;
 	ctx->len = saved_len - count;
 	ctx->npages = npages;
-	iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
+	iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
 	return 0;
 }
 
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index ea92a38b2f08..3e6fe3943591 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2769,13 +2769,13 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 			return 0;
 		}
 
-		iov_iter_bvec(&iter, WRITE | ITER_BVEC, bvec, npages, data_len);
+		iov_iter_bvec(&iter, WRITE, bvec, npages, data_len);
 	} else if (buf_len >= data_offset + data_len) {
 		/* read response payload is in buf */
 		WARN_ONCE(npages > 0, "read data can be either in buf or in pages");
 		iov.iov_base = buf + data_offset;
 		iov.iov_len = data_len;
-		iov_iter_kvec(&iter, WRITE | ITER_KVEC, &iov, 1, data_len);
+		iov_iter_kvec(&iter, WRITE, &iov, 1, data_len);
 	} else {
 		/* read response payload cannot be in both buf and pages */
 		WARN_ONCE(1, "buf can not contain only a part of read data");
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index c55ea4e6201b..10307b46222d 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2047,14 +2047,22 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
 
 	info->smbd_recv_pending++;
 
-	switch (msg->msg_iter.type) {
-	case READ | ITER_KVEC:
+	if (iov_iter_rw(&msg->msg_iter) == WRITE) {
+		/* It's a bug in upper layer to get there */
+		cifs_dbg(VFS, "CIFS: invalid msg iter dir %u\n",
+			 iov_iter_rw(&msg->msg_iter));
+		rc = -EINVAL;
+		goto out;
+	}
+	
+	switch (iov_iter_type(&msg->msg_iter)) {
+	case ITER_KVEC:
 		buf = msg->msg_iter.kvec->iov_base;
 		to_read = msg->msg_iter.kvec->iov_len;
 		rc = smbd_recv_buf(info, buf, to_read);
 		break;
 
-	case READ | ITER_BVEC:
+	case ITER_BVEC:
 		page = msg->msg_iter.bvec->bv_page;
 		page_offset = msg->msg_iter.bvec->bv_offset;
 		to_read = msg->msg_iter.bvec->bv_len;
@@ -2064,10 +2072,11 @@ int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
 	default:
 		/* It's a bug in upper layer to get there */
 		cifs_dbg(VFS, "CIFS: invalid msg type %d\n",
-			msg->msg_iter.type);
+			 iov_iter_type(&msg->msg_iter));
 		rc = -EINVAL;
 	}
 
+out:
 	info->smbd_recv_pending--;
 	wake_up(&info->wait_smbd_recv_pending);
 
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index a341ec839c83..4781de558ab1 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -297,8 +297,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			.iov_base = &rfc1002_marker,
 			.iov_len  = 4
 		};
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, &hiov,
-			      1, 4);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
 			goto uncork;
@@ -319,8 +318,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			size += iov[i].iov_len;
 		}
 
-		iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC,
-			      iov, n_vec, size);
+		iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
 
 		rc = smb_send_kvec(server, &smb_msg, &sent);
 		if (rc < 0)
@@ -336,7 +334,7 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 			rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
 					     &bvec.bv_offset);
 
-			iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
+			iov_iter_bvec(&smb_msg.msg_iter, WRITE,
 				      &bvec, 1, bvec.bv_len);
 			rc = smb_send_kvec(server, &smb_msg, &sent);
 			if (rc < 0)
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 093fb54cd316..989f30cc0d09 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1313,7 +1313,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
 	spin_lock_init(&dio->bio_lock);
 	dio->refcount = 1;
 
-	dio->should_dirty = (iter->type == ITER_IOVEC);
+	dio->should_dirty = iter_is_iovec(iter);
 	sdio.iter = iter;
 	sdio.final_block_in_request = end >> blkbits;
 
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index a5e4a221435c..76976d6e50f9 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -674,7 +674,7 @@ static int receive_from_sock(struct connection *con)
 		nvec = 2;
 	}
 	len = iov[0].iov_len + iov[1].iov_len;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nvec, len);
+	iov_iter_kvec(&msg.msg_iter, READ, iov, nvec, len);
 
 	r = ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
 	if (ret <= 0)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index a201fb0ac64f..fd01af7664e8 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1269,7 +1269,7 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii,
 	ssize_t ret = 0;
 
 	/* Special case for kernel I/O: can copy directly into the buffer */
-	if (ii->type & ITER_KVEC) {
+	if (iov_iter_type(ii) == ITER_KVEC) {
 		unsigned long user_addr = fuse_get_user_addr(ii);
 		size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
 
diff --git a/fs/iomap.c b/fs/iomap.c
index 0d0bd8845586..ad374c9530c3 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1143,7 +1143,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		if (pos >= dio->i_size)
 			goto out_free_dio;
 
-		if (iter->type == ITER_IOVEC)
+		if (iter_is_iovec(iter))
 			dio->flags |= IOMAP_DIO_DIRTY;
 	} else {
 		flags |= IOMAP_WRITE;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index b0555d7d8200..ad61520c8078 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -922,7 +922,7 @@ __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	int host_err;
 
 	trace_nfsd_read_vector(rqstp, fhp, offset, *count);
-	iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
+	iov_iter_kvec(&iter, READ, vec, vlen, *count);
 	host_err = vfs_iter_read(file, &iter, &offset, 0);
 	return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
 }
@@ -998,7 +998,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
 	if (stable && !use_wgather)
 		flags |= RWF_SYNC;
 
-	iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt);
+	iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
 	host_err = vfs_iter_write(file, &iter, &pos, flags);
 	if (host_err < 0)
 		goto out_nfserr;
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index 1296f78ae966..04b651c8309c 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -918,7 +918,7 @@ static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
 {
 	struct kvec vec = { .iov_len = len, .iov_base = data, };
 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, len);
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, len);
 	return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 }
 
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c
index 6e4d2af8f5bc..90815360075a 100644
--- a/fs/orangefs/inode.c
+++ b/fs/orangefs/inode.c
@@ -25,7 +25,7 @@ static int read_one_page(struct page *page)
 	struct iov_iter to;
 	struct bio_vec bv = {.bv_page = page, .bv_len = PAGE_SIZE};
 
-	iov_iter_bvec(&to, ITER_BVEC | READ, &bv, 1, PAGE_SIZE);
+	iov_iter_bvec(&to, READ, &bv, 1, PAGE_SIZE);
 
 	gossip_debug(GOSSIP_INODE_DEBUG,
 		    "orangefs_readpage called with page %p\n",
diff --git a/fs/splice.c b/fs/splice.c
index b3daa971f597..3553f1956508 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -301,7 +301,7 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
 	struct kiocb kiocb;
 	int idx, ret;
 
-	iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len);
+	iov_iter_pipe(&to, READ, pipe, len);
 	idx = to.idx;
 	init_sync_kiocb(&kiocb, in);
 	kiocb.ki_pos = *ppos;
@@ -386,7 +386,7 @@ static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 	 */
 	offset = *ppos & ~PAGE_MASK;
 
-	iov_iter_pipe(&to, ITER_PIPE | READ, pipe, len + offset);
+	iov_iter_pipe(&to, READ, pipe, len + offset);
 
 	res = iov_iter_get_pages_alloc(&to, &pages, len + offset, &base);
 	if (res <= 0)
@@ -745,8 +745,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 			left -= this_len;
 		}
 
-		iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n,
-			      sd.total_len - left);
+		iov_iter_bvec(&from, WRITE, array, n, sd.total_len - left);
 		ret = vfs_iter_write(out, &from, &sd.pos, 0);
 		if (ret <= 0)
 			break;
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 409c845d4cd3..48e7fa36f923 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -21,7 +21,7 @@ struct kvec {
 	size_t iov_len;
 };
 
-enum {
+enum iter_type {
 	ITER_IOVEC = 0,
 	ITER_KVEC = 2,
 	ITER_BVEC = 4,
@@ -29,7 +29,8 @@ enum {
 };
 
 struct iov_iter {
-	int type;
+	enum iter_type iter_type:8;
+	u8 iter_dir;
 	size_t iov_offset;
 	size_t count;
 	union {
@@ -47,6 +48,26 @@ struct iov_iter {
 	};
 };
 
+static inline enum iter_type iov_iter_type(const struct iov_iter *i)
+{
+	return i->iter_type;
+}
+
+static inline bool iov_iter_is_pipe(const struct iov_iter *i)
+{
+	return iov_iter_type(i) == ITER_PIPE;
+}
+
+static inline bool iter_is_iovec(const struct iov_iter *i)
+{
+	return iov_iter_type(i) == ITER_IOVEC;
+}
+
+static inline unsigned char iov_iter_rw(const struct iov_iter *i)
+{
+	return i->iter_dir;
+}
+
 /*
  * Total number of bytes covered by an iovec.
  *
@@ -74,7 +95,8 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
 }
 
 #define iov_for_each(iov, iter, start)				\
-	if (!((start).type & (ITER_BVEC | ITER_PIPE)))		\
+	if (iov_iter_type(start) == ITER_IOVEC ||		\
+	    iov_iter_type(start) == ITER_KVEC)			\
 	for (iter = (start);					\
 	     (iter).count &&					\
 	     ((iov = iov_iter_iovec(&(iter))), 1);		\
@@ -181,13 +203,13 @@ size_t copy_to_iter_mcsafe(void *addr, size_t bytes, struct iov_iter *i)
 size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
 unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
-void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
+void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
 			unsigned long nr_segs, size_t count);
-void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
+void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
 			unsigned long nr_segs, size_t count);
-void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec,
+void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
 			unsigned long nr_segs, size_t count);
-void iov_iter_pipe(struct iov_iter *i, int direction, struct pipe_inode_info *pipe,
+void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
 			size_t count);
 ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
 			size_t maxsize, unsigned maxpages, size_t *start);
@@ -202,19 +224,6 @@ static inline size_t iov_iter_count(const struct iov_iter *i)
 	return i->count;
 }
 
-static inline bool iter_is_iovec(const struct iov_iter *i)
-{
-	return !(i->type & (ITER_BVEC | ITER_KVEC | ITER_PIPE));
-}
-
-/*
- * Get one of READ or WRITE out of iter->type without any other flags OR'd in
- * with it.
- *
- * The ?: is just for type safety.
- */
-#define iov_iter_rw(i) ((0 ? (struct iov_iter *)0 : (i))->type & (READ | WRITE))
-
 /*
  * Cap the iov_iter by given limit; note that the second argument is
  * *not* the new size - it's upper limit for such.  Passing it a value
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 8be175df3075..bd828591afb0 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -75,11 +75,11 @@
 #define iterate_all_kinds(i, n, v, I, B, K) {			\
 	if (likely(n)) {					\
 		size_t skip = i->iov_offset;			\
-		if (unlikely(i->type & ITER_BVEC)) {		\
+		if (unlikely(i->iter_type & ITER_BVEC)) {	\
 			struct bio_vec v;			\
 			struct bvec_iter __bi;			\
 			iterate_bvec(i, n, v, __bi, skip, (B))	\
-		} else if (unlikely(i->type & ITER_KVEC)) {	\
+		} else if (unlikely(i->iter_type & ITER_KVEC)) { \
 			const struct kvec *kvec;		\
 			struct kvec v;				\
 			iterate_kvec(i, n, v, kvec, skip, (K))	\
@@ -96,7 +96,7 @@
 		n = i->count;					\
 	if (i->count) {						\
 		size_t skip = i->iov_offset;			\
-		if (unlikely(i->type & ITER_BVEC)) {		\
+		if (unlikely(i->iter_type & ITER_BVEC)) {		\
 			const struct bio_vec *bvec = i->bvec;	\
 			struct bio_vec v;			\
 			struct bvec_iter __bi;			\
@@ -104,7 +104,7 @@
 			i->bvec = __bvec_iter_bvec(i->bvec, __bi);	\
 			i->nr_segs -= i->bvec - bvec;		\
 			skip = __bi.bi_bvec_done;		\
-		} else if (unlikely(i->type & ITER_KVEC)) {	\
+		} else if (unlikely(i->iter_type & ITER_KVEC)) {	\
 			const struct kvec *kvec;		\
 			struct kvec v;				\
 			iterate_kvec(i, n, v, kvec, skip, (K))	\
@@ -417,28 +417,35 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
 	int err;
 	struct iovec v;
 
-	if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
+	switch (iov_iter_type(i)) {
+	case ITER_IOVEC:
+	case ITER_PIPE:
 		iterate_iovec(i, bytes, v, iov, skip, ({
 			err = fault_in_pages_readable(v.iov_base, v.iov_len);
 			if (unlikely(err))
 			return err;
 		0;}))
+		break;
+	case ITER_KVEC:
+	case ITER_BVEC:
+		break;
 	}
 	return 0;
 }
 EXPORT_SYMBOL(iov_iter_fault_in_readable);
 
-void iov_iter_init(struct iov_iter *i, int direction,
+void iov_iter_init(struct iov_iter *i, unsigned int direction,
 			const struct iovec *iov, unsigned long nr_segs,
 			size_t count)
 {
 	/* It will get better.  Eventually... */
 	if (uaccess_kernel()) {
-		direction |= ITER_KVEC;
-		i->type = direction;
+		i->iter_type = ITER_KVEC;
+		i->iter_dir = direction;
 		i->kvec = (struct kvec *)iov;
 	} else {
-		i->type = direction;
+		i->iter_type = ITER_IOVEC;
+		i->iter_dir = direction;
 		i->iov = iov;
 	}
 	i->nr_segs = nr_segs;
@@ -558,7 +565,7 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
 size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 {
 	const char *from = addr;
-	if (unlikely(i->type & ITER_PIPE))
+	if (unlikely(iov_iter_is_pipe(i)))
 		return copy_pipe_to_iter(addr, bytes, i);
 	if (iter_is_iovec(i))
 		might_fault();
@@ -658,7 +665,7 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
 	const char *from = addr;
 	unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
 
-	if (unlikely(i->type & ITER_PIPE))
+	if (unlikely(iov_iter_is_pipe(i)))
 		return copy_pipe_to_iter_mcsafe(addr, bytes, i);
 	if (iter_is_iovec(i))
 		might_fault();
@@ -692,7 +699,7 @@ EXPORT_SYMBOL_GPL(_copy_to_iter_mcsafe);
 size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
 	char *to = addr;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return 0;
 	}
@@ -712,7 +719,7 @@ EXPORT_SYMBOL(_copy_from_iter);
 bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
 {
 	char *to = addr;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return false;
 	}
@@ -739,7 +746,7 @@ EXPORT_SYMBOL(_copy_from_iter_full);
 size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 {
 	char *to = addr;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return 0;
 	}
@@ -773,7 +780,7 @@ EXPORT_SYMBOL(_copy_from_iter_nocache);
 size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 {
 	char *to = addr;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return 0;
 	}
@@ -794,7 +801,7 @@ EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);
 bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
 {
 	char *to = addr;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return false;
 	}
@@ -831,15 +838,20 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
 {
 	if (unlikely(!page_copy_sane(page, offset, bytes)))
 		return 0;
-	if (i->type & (ITER_BVEC|ITER_KVEC)) {
+	switch (iov_iter_type(i)) {
+	case ITER_BVEC:
+	case ITER_KVEC: {
 		void *kaddr = kmap_atomic(page);
 		size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
 		kunmap_atomic(kaddr);
 		return wanted;
-	} else if (likely(!(i->type & ITER_PIPE)))
+	}
+	case ITER_IOVEC:
 		return copy_page_to_iter_iovec(page, offset, bytes, i);
-	else
+	case ITER_PIPE:
 		return copy_page_to_iter_pipe(page, offset, bytes, i);
+	}
+	BUG();
 }
 EXPORT_SYMBOL(copy_page_to_iter);
 
@@ -848,17 +860,21 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
 {
 	if (unlikely(!page_copy_sane(page, offset, bytes)))
 		return 0;
-	if (unlikely(i->type & ITER_PIPE)) {
-		WARN_ON(1);
-		return 0;
-	}
-	if (i->type & (ITER_BVEC|ITER_KVEC)) {
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE:
+		break;
+	case ITER_BVEC:
+	case ITER_KVEC: {
 		void *kaddr = kmap_atomic(page);
 		size_t wanted = _copy_from_iter(kaddr + offset, bytes, i);
 		kunmap_atomic(kaddr);
 		return wanted;
-	} else
+	}
+	case ITER_IOVEC:
 		return copy_page_from_iter_iovec(page, offset, bytes, i);
+	}
+	WARN_ON(1);
+	return 0;
 }
 EXPORT_SYMBOL(copy_page_from_iter);
 
@@ -888,7 +904,7 @@ static size_t pipe_zero(size_t bytes, struct iov_iter *i)
 
 size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 {
-	if (unlikely(i->type & ITER_PIPE))
+	if (unlikely(iov_iter_is_pipe(i)))
 		return pipe_zero(bytes, i);
 	iterate_and_advance(i, bytes, v,
 		clear_user(v.iov_base, v.iov_len),
@@ -908,7 +924,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 		kunmap_atomic(kaddr);
 		return 0;
 	}
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		kunmap_atomic(kaddr);
 		WARN_ON(1);
 		return 0;
@@ -972,7 +988,7 @@ static void pipe_advance(struct iov_iter *i, size_t size)
 
 void iov_iter_advance(struct iov_iter *i, size_t size)
 {
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		pipe_advance(i, size);
 		return;
 	}
@@ -987,7 +1003,7 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
 	if (WARN_ON(unroll > MAX_RW_COUNT))
 		return;
 	i->count += unroll;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		struct pipe_inode_info *pipe = i->pipe;
 		int idx = i->idx;
 		size_t off = i->iov_offset;
@@ -1016,7 +1032,8 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
 		return;
 	}
 	unroll -= i->iov_offset;
-	if (i->type & ITER_BVEC) {
+	switch (iov_iter_type(i)) {
+	case ITER_BVEC: {
 		const struct bio_vec *bvec = i->bvec;
 		while (1) {
 			size_t n = (--bvec)->bv_len;
@@ -1028,7 +1045,10 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
 			}
 			unroll -= n;
 		}
-	} else { /* same logics for iovec and kvec */
+	}
+	case ITER_IOVEC:
+	case ITER_KVEC: {
+		/* same logics for iovec and kvec */
 		const struct iovec *iov = i->iov;
 		while (1) {
 			size_t n = (--iov)->iov_len;
@@ -1041,6 +1061,9 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
 			unroll -= n;
 		}
 	}
+	case ITER_PIPE:
+		BUG();
+	}
 }
 EXPORT_SYMBOL(iov_iter_revert);
 
@@ -1049,23 +1072,28 @@ EXPORT_SYMBOL(iov_iter_revert);
  */
 size_t iov_iter_single_seg_count(const struct iov_iter *i)
 {
-	if (unlikely(i->type & ITER_PIPE))
-		return i->count;	// it is a silly place, anyway
 	if (i->nr_segs == 1)
 		return i->count;
-	else if (i->type & ITER_BVEC)
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE:
+		return i->count;	// it is a silly place, anyway
+	case ITER_BVEC:
 		return min(i->count, i->bvec->bv_len - i->iov_offset);
-	else
+	case ITER_KVEC:
+	case ITER_IOVEC:
 		return min(i->count, i->iov->iov_len - i->iov_offset);
+	}
+	BUG();
 }
 EXPORT_SYMBOL(iov_iter_single_seg_count);
 
-void iov_iter_kvec(struct iov_iter *i, int direction,
+void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
 			const struct kvec *kvec, unsigned long nr_segs,
 			size_t count)
 {
-	BUG_ON(!(direction & ITER_KVEC));
-	i->type = direction;
+	BUG_ON(direction & ~1);
+	i->iter_dir = direction;
+	i->iter_type = ITER_KVEC;
 	i->kvec = kvec;
 	i->nr_segs = nr_segs;
 	i->iov_offset = 0;
@@ -1073,12 +1101,13 @@ void iov_iter_kvec(struct iov_iter *i, int direction,
 }
 EXPORT_SYMBOL(iov_iter_kvec);
 
-void iov_iter_bvec(struct iov_iter *i, int direction,
+void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
 			const struct bio_vec *bvec, unsigned long nr_segs,
 			size_t count)
 {
-	BUG_ON(!(direction & ITER_BVEC));
-	i->type = direction;
+	BUG_ON(direction & ~1);
+	i->iter_dir = direction;
+	i->iter_type = ITER_BVEC;
 	i->bvec = bvec;
 	i->nr_segs = nr_segs;
 	i->iov_offset = 0;
@@ -1086,13 +1115,14 @@ void iov_iter_bvec(struct iov_iter *i, int direction,
 }
 EXPORT_SYMBOL(iov_iter_bvec);
 
-void iov_iter_pipe(struct iov_iter *i, int direction,
+void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
 			struct pipe_inode_info *pipe,
 			size_t count)
 {
-	BUG_ON(direction != ITER_PIPE);
+	BUG_ON(direction != READ);
 	WARN_ON(pipe->nrbufs == pipe->buffers);
-	i->type = direction;
+	i->iter_dir = READ;
+	i->iter_type = ITER_PIPE;
 	i->pipe = pipe;
 	i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
 	i->iov_offset = 0;
@@ -1106,7 +1136,7 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 	unsigned long res = 0;
 	size_t size = i->count;
 
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx]))
 			return size | i->iov_offset;
 		return size;
@@ -1125,7 +1155,7 @@ unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
 	unsigned long res = 0;
 	size_t size = i->count;
 
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return ~0U;
 	}
@@ -1193,7 +1223,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 	if (maxsize > i->count)
 		maxsize = i->count;
 
-	if (unlikely(i->type & ITER_PIPE))
+	if (unlikely(iov_iter_is_pipe(i)))
 		return pipe_get_pages(i, pages, maxsize, maxpages, start);
 	iterate_all_kinds(i, maxsize, v, ({
 		unsigned long addr = (unsigned long)v.iov_base;
@@ -1205,7 +1235,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 			len = maxpages * PAGE_SIZE;
 		addr &= ~(PAGE_SIZE - 1);
 		n = DIV_ROUND_UP(len, PAGE_SIZE);
-		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
+		res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, pages);
 		if (unlikely(res < 0))
 			return res;
 		return (res == n ? len : res * PAGE_SIZE) - *start;
@@ -1270,7 +1300,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 	if (maxsize > i->count)
 		maxsize = i->count;
 
-	if (unlikely(i->type & ITER_PIPE))
+	if (unlikely(iov_iter_is_pipe(i)))
 		return pipe_get_pages_alloc(i, pages, maxsize, start);
 	iterate_all_kinds(i, maxsize, v, ({
 		unsigned long addr = (unsigned long)v.iov_base;
@@ -1283,7 +1313,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 		p = get_pages_array(n);
 		if (!p)
 			return -ENOMEM;
-		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
+		res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE, p);
 		if (unlikely(res < 0)) {
 			kvfree(p);
 			return res;
@@ -1313,7 +1343,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return 0;
 	}
@@ -1355,7 +1385,7 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);
 		return false;
 	}
@@ -1400,7 +1430,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		WARN_ON(1);	/* for now */
 		return 0;
 	}
@@ -1443,7 +1473,7 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
 	if (!size)
 		return 0;
 
-	if (unlikely(i->type & ITER_PIPE)) {
+	if (unlikely(iov_iter_is_pipe(i))) {
 		struct pipe_inode_info *pipe = i->pipe;
 		size_t off;
 		int idx;
@@ -1481,19 +1511,23 @@ EXPORT_SYMBOL(iov_iter_npages);
 const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
 {
 	*new = *old;
-	if (unlikely(new->type & ITER_PIPE)) {
-		WARN_ON(1);
-		return NULL;
-	}
-	if (new->type & ITER_BVEC)
+	switch (iov_iter_type(new)) {
+	case ITER_PIPE:
+		break;
+	case ITER_BVEC:
 		return new->bvec = kmemdup(new->bvec,
 				    new->nr_segs * sizeof(struct bio_vec),
 				    flags);
-	else
+	case ITER_IOVEC:
+	case ITER_KVEC:
 		/* iovec and kvec have identical layout */
 		return new->iov = kmemdup(new->iov,
 				   new->nr_segs * sizeof(struct iovec),
 				   flags);
+	}
+
+	WARN_ON(1);
+	return NULL;
 }
 EXPORT_SYMBOL(dup_iter);
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 52517f28e6f4..bdeee0168ea7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2122,7 +2122,7 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb,
 					!mapping->a_ops->is_partially_uptodate)
 				goto page_not_up_to_date;
 			/* pipes can't handle partially uptodate pages */
-			if (unlikely(iter->type & ITER_PIPE))
+			if (unlikely(iov_iter_is_pipe(iter)))
 				goto page_not_up_to_date;
 			if (!trylock_page(page))
 				goto page_not_up_to_date;
diff --git a/mm/page_io.c b/mm/page_io.c
index b41cf9644585..23c5756142bb 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -294,7 +294,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 		};
 		struct iov_iter from;
 
-		iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE);
+		iov_iter_bvec(&from, WRITE, &bv, 1, PAGE_SIZE);
 		init_sync_kiocb(&kiocb, swap_file);
 		kiocb.ki_pos = page_file_offset(page);
 
diff --git a/net/9p/client.c b/net/9p/client.c
index 5c1343195292..1e853e2a62bb 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -2089,7 +2089,7 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
 	struct kvec kv = {.iov_base = data, .iov_len = count};
 	struct iov_iter to;
 
-	iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
+	iov_iter_kvec(&to, READ, &kv, 1, count);
 
 	p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
 				fid->fid, (unsigned long long) offset, count);
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 05006cbb3361..457cd9fcdd4f 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -320,7 +320,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
 	if (!iov_iter_count(data))
 		return 0;
 
-	if (!(data->type & ITER_KVEC)) {
+	if (iov_iter_type(data) != ITER_KVEC) {
 		int n;
 		/*
 		 * We allow only p9_max_pages pinned. We wait for the
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 4e2576fc0c59..828e87fe8027 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -467,7 +467,7 @@ static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 	iv.iov_len = skb->len;
 
 	memset(&msg, 0, sizeof(msg));
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
 
 	err = l2cap_chan_send(chan, &msg, skb->len);
 	if (err > 0) {
diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index 51c2cf2d8923..58fc6333d412 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -63,7 +63,7 @@ static void a2mp_send(struct amp_mgr *mgr, u8 code, u8 ident, u16 len, void *dat
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, total_len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, total_len);
 
 	l2cap_chan_send(chan, &msg, total_len);
 
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index ae91e2d40056..5f4c9f8333fd 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -622,7 +622,7 @@ static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
 
 	memset(&msg, 0, sizeof(msg));
 
-	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iv, 2, 1 + len);
+	iov_iter_kvec(&msg.msg_iter, WRITE, iv, 2, 1 + len);
 
 	l2cap_chan_send(chan, &msg, 1 + len);
 
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c6413c360771..fcbe49f5b704 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -526,7 +526,7 @@ static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
 	if (!buf)
 		msg.msg_flags |= MSG_TRUNC;
 
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, len);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, len);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
@@ -545,7 +545,7 @@ static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
 	int r;
 
 	BUG_ON(page_offset + length > PAGE_SIZE);
-	iov_iter_bvec(&msg.msg_iter, READ | ITER_BVEC, &bvec, 1, length);
+	iov_iter_bvec(&msg.msg_iter, READ, &bvec, 1, length);
 	r = sock_recvmsg(sock, &msg, msg.msg_flags);
 	if (r == -EAGAIN)
 		r = 0;
@@ -607,7 +607,7 @@ static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
 	else
 		msg.msg_flags |= MSG_EOR;  /* superfluous, but what the hell */
 
-	iov_iter_bvec(&msg.msg_iter, WRITE | ITER_BVEC, &bvec, 1, size);
+	iov_iter_bvec(&msg.msg_iter, WRITE, &bvec, 1, size);
 	ret = sock_sendmsg(sock, &msg);
 	if (ret == -EAGAIN)
 		ret = 0;
diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index d4020c5e831d..2526be6b3d90 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1616,7 +1616,7 @@ ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
 	EnterFunction(7);
 
 	/* Receive a packet */
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, buflen);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, buflen);
 	len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);
 	if (len < 0)
 		return len;
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 83aba9ade060..f27a298f3498 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -286,7 +286,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	 */
 	krflags = MSG_PEEK | MSG_WAITALL;
 	smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1,
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1,
 			sizeof(struct smc_clc_msg_hdr));
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (signal_pending(current)) {
@@ -325,7 +325,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 
 	/* receive the complete CLC message */
 	memset(&msg, 0, sizeof(struct msghdr));
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, datlen);
+	iov_iter_kvec(&msg.msg_iter, READ, &vec, 1, datlen);
 	krflags = MSG_WAITALL;
 	len = sock_recvmsg(smc->clcsock, &msg, krflags);
 	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
diff --git a/net/socket.c b/net/socket.c
index 0d8cfc0c9b2a..52ea48a2e601 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -655,7 +655,7 @@ EXPORT_SYMBOL(sock_sendmsg);
 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size)
 {
-	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 	return sock_sendmsg(sock, msg);
 }
 EXPORT_SYMBOL(kernel_sendmsg);
@@ -668,7 +668,7 @@ int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 	if (!sock->ops->sendmsg_locked)
 		return sock_no_sendmsg_locked(sk, msg, size);
 
-	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 
 	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
 }
@@ -843,7 +843,7 @@ int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 	mm_segment_t oldfs = get_fs();
 	int result;
 
-	iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
 	set_fs(KERNEL_DS);
 	result = sock_recvmsg(sock, msg, flags);
 	set_fs(oldfs);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 5445145e639c..0b46ec0bf74e 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -338,7 +338,7 @@ static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
 	rqstp->rq_xprt_hlen = 0;
 
 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nr, buflen);
+	iov_iter_kvec(&msg.msg_iter, READ, iov, nr, buflen);
 	len = sock_recvmsg(svsk->sk_sock, &msg, msg.msg_flags);
 	/* If we read a full record, then assume there may be more
 	 * data to read (stream based sockets only!)
diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c
index c8e34ef22c30..7e0f8df6b79d 100644
--- a/net/tipc/topsrv.c
+++ b/net/tipc/topsrv.c
@@ -400,7 +400,7 @@ static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
 	iov.iov_base = &s;
 	iov.iov_len = sizeof(s);
 	msg.msg_name = NULL;
-	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len);
+	iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, iov.iov_len);
 	ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
 	if (ret == -EWOULDBLOCK)
 		return -EWOULDBLOCK;
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 292742e50bfa..fcf50375cd05 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -489,7 +489,7 @@ int tls_device_sendpage(struct sock *sk, struct page *page,
 
 	iov.iov_base = kaddr + offset;
 	iov.iov_len = size;
-	iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, &iov, 1, size);
+	iov_iter_kvec(&msg_iter, WRITE, &iov, 1, size);
 	rc = tls_push_data(sk, &msg_iter, size,
 			   flags, TLS_RECORD_TYPE_DATA);
 	kunmap(page);
@@ -538,7 +538,7 @@ static int tls_device_push_pending_record(struct sock *sk, int flags)
 {
 	struct iov_iter	msg_iter;
 
-	iov_iter_kvec(&msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+	iov_iter_kvec(&msg_iter, WRITE, NULL, 0, 0);
 	return tls_push_data(sk, &msg_iter, 0, flags, TLS_RECORD_TYPE_DATA);
 }
 
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 83d67df33f0c..0047e75ac4db 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -365,7 +365,7 @@ int tls_sw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 	int record_room;
 	bool full_record;
 	int orig_size;
-	bool is_kvec = msg->msg_iter.type & ITER_KVEC;
+	bool is_kvec = iov_iter_type(&msg->msg_iter) == ITER_KVEC;
 
 	if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL))
 		return -ENOTSUPP;
@@ -778,7 +778,7 @@ int tls_sw_recvmsg(struct sock *sk,
 	bool cmsg = false;
 	int target, err = 0;
 	long timeo;
-	bool is_kvec = msg->msg_iter.type & ITER_KVEC;
+	bool is_kvec = iov_iter_type(&msg->msg_iter) == ITER_KVEC;
 
 	flags |= nonblock;
 

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 02/10] iov_iter: Renumber the ITER_* constants in uio.h
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
  2018-08-06 13:16 ` [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions David Howells
@ 2018-08-06 13:16 ` David Howells
  2018-08-06 13:16 ` [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t David Howells
                   ` (7 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:16 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Renumber the ITER_* constants in uio.h to be contiguous to make comparing
them more efficient in a switch-statement.

Signed-off-by: David Howells <dhowelsl@redhat.com>
---

 include/linux/uio.h |    8 +++---
 lib/iov_iter.c      |   69 +++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 48e7fa36f923..d5f8755bf778 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -22,10 +22,10 @@ struct kvec {
 };
 
 enum iter_type {
-	ITER_IOVEC = 0,
-	ITER_KVEC = 2,
-	ITER_BVEC = 4,
-	ITER_PIPE = 8,
+	ITER_IOVEC,
+	ITER_KVEC,
+	ITER_BVEC,
+	ITER_PIPE,
 };
 
 struct iov_iter {
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index bd828591afb0..f30ecd263d6e 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -75,18 +75,28 @@
 #define iterate_all_kinds(i, n, v, I, B, K) {			\
 	if (likely(n)) {					\
 		size_t skip = i->iov_offset;			\
-		if (unlikely(i->iter_type & ITER_BVEC)) {	\
+		switch (iov_iter_type(i)) {			\
+		case ITER_BVEC: {				\
 			struct bio_vec v;			\
 			struct bvec_iter __bi;			\
-			iterate_bvec(i, n, v, __bi, skip, (B))	\
-		} else if (unlikely(i->iter_type & ITER_KVEC)) { \
+			iterate_bvec(i, n, v, __bi, skip, (B));	\
+			break;					\
+		}						\
+		case ITER_KVEC: {				\
 			const struct kvec *kvec;		\
 			struct kvec v;				\
-			iterate_kvec(i, n, v, kvec, skip, (K))	\
-		} else {					\
+			iterate_kvec(i, n, v, kvec, skip, (K));	\
+			break;					\
+		}						\
+		case ITER_PIPE: {				\
+			break;					\
+		}						\
+		case ITER_IOVEC: {				\
 			const struct iovec *iov;		\
 			struct iovec v;				\
-			iterate_iovec(i, n, v, iov, skip, (I))	\
+			iterate_iovec(i, n, v, iov, skip, (I));	\
+			break;					\
+		}						\
 		}						\
 	}							\
 }
@@ -96,7 +106,8 @@
 		n = i->count;					\
 	if (i->count) {						\
 		size_t skip = i->iov_offset;			\
-		if (unlikely(i->iter_type & ITER_BVEC)) {		\
+		switch (iov_iter_type(i)) {			\
+		case ITER_BVEC: {				\
 			const struct bio_vec *bvec = i->bvec;	\
 			struct bio_vec v;			\
 			struct bvec_iter __bi;			\
@@ -104,7 +115,9 @@
 			i->bvec = __bvec_iter_bvec(i->bvec, __bi);	\
 			i->nr_segs -= i->bvec - bvec;		\
 			skip = __bi.bi_bvec_done;		\
-		} else if (unlikely(i->iter_type & ITER_KVEC)) {	\
+			break;					\
+		}						\
+		case ITER_KVEC: {				\
 			const struct kvec *kvec;		\
 			struct kvec v;				\
 			iterate_kvec(i, n, v, kvec, skip, (K))	\
@@ -114,7 +127,9 @@
 			}					\
 			i->nr_segs -= kvec - i->kvec;		\
 			i->kvec = kvec;				\
-		} else {					\
+			break;					\
+		}						\
+		case ITER_IOVEC: {				\
 			const struct iovec *iov;		\
 			struct iovec v;				\
 			iterate_iovec(i, n, v, iov, skip, (I))	\
@@ -124,6 +139,11 @@
 			}					\
 			i->nr_segs -= iov - i->iov;		\
 			i->iov = iov;				\
+			break;					\
+		}						\
+		case ITER_PIPE: {				\
+			break;					\
+		}						\
 		}						\
 		i->count -= n;					\
 		i->iov_offset = skip;				\
@@ -873,6 +893,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
 	case ITER_IOVEC:
 		return copy_page_from_iter_iovec(page, offset, bytes, i);
 	}
+
 	WARN_ON(1);
 	return 0;
 }
@@ -988,11 +1009,17 @@ static void pipe_advance(struct iov_iter *i, size_t size)
 
 void iov_iter_advance(struct iov_iter *i, size_t size)
 {
-	if (unlikely(iov_iter_is_pipe(i))) {
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE:
 		pipe_advance(i, size);
 		return;
+	case ITER_IOVEC:
+	case ITER_KVEC:
+	case ITER_BVEC:
+		iterate_and_advance(i, size, v, 0, 0, 0);
+		return;
 	}
-	iterate_and_advance(i, size, v, 0, 0, 0)
+	BUG();
 }
 EXPORT_SYMBOL(iov_iter_advance);
 
@@ -1223,8 +1250,16 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 	if (maxsize > i->count)
 		maxsize = i->count;
 
-	if (unlikely(iov_iter_is_pipe(i)))
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE:
 		return pipe_get_pages(i, pages, maxsize, maxpages, start);
+	case ITER_KVEC:
+		return -EFAULT;
+	case ITER_IOVEC:
+	case ITER_BVEC:
+		break;
+	}
+
 	iterate_all_kinds(i, maxsize, v, ({
 		unsigned long addr = (unsigned long)v.iov_base;
 		size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
@@ -1300,8 +1335,16 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 	if (maxsize > i->count)
 		maxsize = i->count;
 
-	if (unlikely(iov_iter_is_pipe(i)))
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE:
 		return pipe_get_pages_alloc(i, pages, maxsize, start);
+	case ITER_KVEC:
+		return -EFAULT;
+	case ITER_IOVEC:
+	case ITER_BVEC:
+		break;
+	}
+
 	iterate_all_kinds(i, maxsize, v, ({
 		unsigned long addr = (unsigned long)v.iov_base;
 		size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
  2018-08-06 13:16 ` [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions David Howells
  2018-08-06 13:16 ` [PATCH 02/10] iov_iter: Renumber the ITER_* constants in uio.h David Howells
@ 2018-08-06 13:16 ` David Howells
  2018-08-06 13:17 ` [PATCH 04/10] iov_iter: Add mapping and discard iterator types David Howells
                   ` (6 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:16 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Make count and iov_offset loff_t not size_t so that they can handle
transactions larger than 4GiB in size and starting at 4GiB or more into a
file on a 32-bit system.

On a 64-bit system, this should make no difference.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/9p/vfs_file.c    |    2 +-
 fs/btrfs/file.c     |    7 ++++---
 fs/nfs/direct.c     |    2 +-
 fs/nfs/file.c       |    4 ++--
 include/linux/uio.h |    6 +++---
 lib/iov_iter.c      |   14 +++++++-------
 net/9p/client.c     |    2 +-
 net/rxrpc/recvmsg.c |    4 ++--
 8 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 03c9e325bfbc..a83b81ea677f 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -384,7 +384,7 @@ v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	struct p9_fid *fid = iocb->ki_filp->private_data;
 	int ret, err = 0;
 
-	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
+	p9_debug(P9_DEBUG_VFS, "count %llu offset %lld\n",
 		 iov_iter_count(to), iocb->ki_pos);
 
 	ret = p9_client_read(fid, iocb->ki_pos, to, &err);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 51e77d72068a..48bf2b0af7b5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1599,9 +1599,10 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 	while (iov_iter_count(i) > 0) {
 		size_t offset = pos & (PAGE_SIZE - 1);
 		size_t sector_offset;
-		size_t write_bytes = min(iov_iter_count(i),
-					 nrptrs * (size_t)PAGE_SIZE -
-					 offset);
+		size_t write_bytes = min_t(size_t,
+					   iov_iter_count(i),
+					   nrptrs * (size_t)PAGE_SIZE -
+					   offset);
 		size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
 						PAGE_SIZE);
 		size_t reserve_bytes;
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 621c517b325c..3d438aa2650b 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -974,7 +974,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
 	struct nfs_lock_context *l_ctx;
 	loff_t pos, end;
 
-	dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n",
+	dfprintk(FILE, "NFS: direct write(%pD2, %lld@%lld)\n",
 		file, iov_iter_count(iter), (long long) iocb->ki_pos);
 
 	result = generic_write_checks(iocb, iter);
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 81cca49a8375..ef4fd7124ca1 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -159,7 +159,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
 	if (iocb->ki_flags & IOCB_DIRECT)
 		return nfs_file_direct_read(iocb, to);
 
-	dprintk("NFS: read(%pD2, %zu@%lu)\n",
+	dprintk("NFS: read(%pD2, %llu@%lu)\n",
 		iocb->ki_filp,
 		iov_iter_count(to), (unsigned long) iocb->ki_pos);
 
@@ -608,7 +608,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
 	if (iocb->ki_flags & IOCB_DIRECT)
 		return nfs_file_direct_write(iocb, from);
 
-	dprintk("NFS: write(%pD2, %zu@%Ld)\n",
+	dprintk("NFS: write(%pD2, %llu@%Ld)\n",
 		file, iov_iter_count(from), (long long) iocb->ki_pos);
 
 	if (IS_SWAPFILE(inode))
diff --git a/include/linux/uio.h b/include/linux/uio.h
index d5f8755bf778..d0655b74fd7e 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -31,7 +31,7 @@ enum iter_type {
 struct iov_iter {
 	enum iter_type iter_type:8;
 	u8 iter_dir;
-	size_t iov_offset;
+	loff_t iov_offset;
 	size_t count;
 	union {
 		const struct iovec *iov;
@@ -89,7 +89,7 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
 {
 	return (struct iovec) {
 		.iov_base = iter->iov->iov_base + iter->iov_offset,
-		.iov_len = min(iter->count,
+		.iov_len = min_t(size_t, iter->count,
 			       iter->iov->iov_len - iter->iov_offset),
 	};
 }
@@ -219,7 +219,7 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages);
 
 const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags);
 
-static inline size_t iov_iter_count(const struct iov_iter *i)
+static inline loff_t iov_iter_count(const struct iov_iter *i)
 {
 	return i->count;
 }
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f30ecd263d6e..8231f0e38f20 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -13,7 +13,7 @@
 	size_t left;					\
 	size_t wanted = n;				\
 	__p = i->iov;					\
-	__v.iov_len = min(n, __p->iov_len - skip);	\
+	__v.iov_len = min_t(size_t, n, __p->iov_len - skip);	\
 	if (likely(__v.iov_len)) {			\
 		__v.iov_base = __p->iov_base + skip;	\
 		left = (STEP);				\
@@ -40,7 +40,7 @@
 #define iterate_kvec(i, n, __v, __p, skip, STEP) {	\
 	size_t wanted = n;				\
 	__p = i->kvec;					\
-	__v.iov_len = min(n, __p->iov_len - skip);	\
+	__v.iov_len = min_t(size_t, n, __p->iov_len - skip);	\
 	if (likely(__v.iov_len)) {			\
 		__v.iov_base = __p->iov_base + skip;	\
 		(void)(STEP);				\
@@ -74,7 +74,7 @@
 
 #define iterate_all_kinds(i, n, v, I, B, K) {			\
 	if (likely(n)) {					\
-		size_t skip = i->iov_offset;			\
+		loff_t skip = i->iov_offset;			\
 		switch (iov_iter_type(i)) {			\
 		case ITER_BVEC: {				\
 			struct bio_vec v;			\
@@ -105,7 +105,7 @@
 	if (unlikely(i->count < n))				\
 		n = i->count;					\
 	if (i->count) {						\
-		size_t skip = i->iov_offset;			\
+		loff_t skip = i->iov_offset;			\
 		switch (iov_iter_type(i)) {			\
 		case ITER_BVEC: {				\
 			const struct bio_vec *bvec = i->bvec;	\
@@ -358,7 +358,7 @@ static bool sanity(const struct iov_iter *i)
 	}
 	return true;
 Bad:
-	printk(KERN_ERR "idx = %d, offset = %zd\n", i->idx, i->iov_offset);
+	printk(KERN_ERR "idx = %d, offset = %lld\n", i->idx, i->iov_offset);
 	printk(KERN_ERR "curbuf = %d, nrbufs = %d, buffers = %d\n",
 			pipe->curbuf, pipe->nrbufs, pipe->buffers);
 	for (idx = 0; idx < pipe->buffers; idx++)
@@ -1105,10 +1105,10 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
 	case ITER_PIPE:
 		return i->count;	// it is a silly place, anyway
 	case ITER_BVEC:
-		return min(i->count, i->bvec->bv_len - i->iov_offset);
+		return min_t(size_t, i->count, i->bvec->bv_len - i->iov_offset);
 	case ITER_KVEC:
 	case ITER_IOVEC:
-		return min(i->count, i->iov->iov_len - i->iov_offset);
+		return min_t(size_t, i->count, i->iov->iov_len - i->iov_offset);
 	}
 	BUG();
 }
diff --git a/net/9p/client.c b/net/9p/client.c
index 1e853e2a62bb..19b045714206 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1649,7 +1649,7 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
 	int total = 0;
 	*err = 0;
 
-	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
+	p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %llu\n",
 				fid->fid, (unsigned long long) offset,
 				iov_iter_count(from));
 
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 816b19a78809..920f505baedd 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -633,7 +633,7 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
 	size_t offset = 0;
 	int ret;
 
-	_enter("{%d,%s},%zu,%d",
+	_enter("{%d,%s},%llu,%d",
 	       call->debug_id, rxrpc_call_states[call->state],
 	       iov_iter_count(iter), want_more);
 
@@ -693,7 +693,7 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
 	if (_service)
 		*_service = call->service_id;
 	mutex_unlock(&call->user_mutex);
-	_leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
+	_leave(" = %d [%llu,%d]", ret, iov_iter_count(iter), *_abort);
 	return ret;
 
 short_data:

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 04/10] iov_iter: Add mapping and discard iterator types
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (2 preceding siblings ...)
  2018-08-06 13:16 ` [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 05/10] afs: Better tracing of protocol errors David Howells
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Add two new iterator types to iov_iter:

 (1) ITER_MAPPING

     This walks through a set of pages attached to an address_space that
     are pinned or locked, starting at a given page and offset and walking
     for the specified amount of space.  A facility to get a callback each
     time a page is entirely processed is provided.

     This is useful for copying data from socket buffers to inodes in
     network filesystems.

 (2) ITER_DISCARD

     This is a sink iterator that can only be used in READ mode and just
     discards any data copied to it.

     This is useful in a network filesystem for discarding any unwanted
     data sent by a server.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/linux/uio.h |    8 +
 lib/iov_iter.c      |  365 +++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 330 insertions(+), 43 deletions(-)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index d0655b74fd7e..24f6901472e9 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -14,6 +14,7 @@
 #include <uapi/linux/uio.h>
 
 struct page;
+struct address_space;
 struct pipe_inode_info;
 
 struct kvec {
@@ -26,6 +27,8 @@ enum iter_type {
 	ITER_KVEC,
 	ITER_BVEC,
 	ITER_PIPE,
+	ITER_DISCARD,
+	ITER_MAPPING,
 };
 
 struct iov_iter {
@@ -37,6 +40,7 @@ struct iov_iter {
 		const struct iovec *iov;
 		const struct kvec *kvec;
 		const struct bio_vec *bvec;
+		struct address_space *mapping;
 		struct pipe_inode_info *pipe;
 	};
 	union {
@@ -45,6 +49,7 @@ struct iov_iter {
 			int idx;
 			int start_idx;
 		};
+		void (*page_done)(const struct iov_iter *, const struct bio_vec *);
 	};
 };
 
@@ -211,6 +216,9 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_
 			unsigned long nr_segs, size_t count);
 void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
 			size_t count);
+void iov_iter_mapping(struct iov_iter *i, unsigned int direction, struct address_space *mapping,
+		      loff_t start, size_t count);
+void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
 ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
 			size_t maxsize, unsigned maxpages, size_t *start);
 ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 8231f0e38f20..22b35464891b 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -72,7 +72,35 @@
 	}						\
 }
 
-#define iterate_all_kinds(i, n, v, I, B, K) {			\
+#define iterate_mapping(i, n, __v, do_done, skip, STEP) {	\
+	struct radix_tree_iter cursor;				\
+	size_t wanted = n, seg, offset;				\
+	pgoff_t index = skip >> PAGE_SHIFT;			\
+	void __rcu **slot;					\
+								\
+	rcu_read_lock();					\
+	radix_tree_for_each_contig(slot, &i->mapping->i_pages,	\
+				   &cursor, index) {		\
+		if (!n)						\
+			break;					\
+		__v.bv_page = radix_tree_deref_slot(slot);	\
+		if (!__v.bv_page)				\
+			break;					\
+		offset = skip & ~PAGE_MASK;			\
+		seg = PAGE_SIZE - offset;			\
+		__v.bv_offset = offset;				\
+		__v.bv_len = min(n, seg);			\
+		(void)(STEP);					\
+		if (do_done && __v.bv_offset + __v.bv_len == PAGE_SIZE)	\
+			i->page_done(i, &__v);			\
+		n -= __v.bv_len;				\
+		skip += __v.bv_len;				\
+	}							\
+	rcu_read_unlock();					\
+	n = wanted - n;						\
+}
+
+#define iterate_all_kinds(i, n, v, I, B, K, M) {		\
 	if (likely(n)) {					\
 		loff_t skip = i->iov_offset;			\
 		switch (iov_iter_type(i)) {			\
@@ -91,6 +119,14 @@
 		case ITER_PIPE: {				\
 			break;					\
 		}						\
+		case ITER_MAPPING: {				\
+			struct bio_vec v;			\
+			iterate_mapping(i, n, v, false, skip, (M));	\
+			break;					\
+		}						\
+		case ITER_DISCARD: {				\
+			break;					\
+		}						\
 		case ITER_IOVEC: {				\
 			const struct iovec *iov;		\
 			struct iovec v;				\
@@ -101,7 +137,7 @@
 	}							\
 }
 
-#define iterate_and_advance(i, n, v, I, B, K) {			\
+#define iterate_and_advance(i, n, v, I, B, K, M) {		\
 	if (unlikely(i->count < n))				\
 		n = i->count;					\
 	if (i->count) {						\
@@ -129,6 +165,11 @@
 			i->kvec = kvec;				\
 			break;					\
 		}						\
+		case ITER_MAPPING: {				\
+			struct bio_vec v;			\
+			iterate_mapping(i, n, v, i->page_done, skip, (M))	\
+			break;					\
+		}						\
 		case ITER_IOVEC: {				\
 			const struct iovec *iov;		\
 			struct iovec v;				\
@@ -144,6 +185,10 @@
 		case ITER_PIPE: {				\
 			break;					\
 		}						\
+		case ITER_DISCARD: {				\
+			skip += n;				\
+			break;					\
+		}						\
 		}						\
 		i->count -= n;					\
 		i->iov_offset = skip;				\
@@ -448,6 +493,8 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
 		break;
 	case ITER_KVEC:
 	case ITER_BVEC:
+	case ITER_MAPPING:
+	case ITER_DISCARD:
 		break;
 	}
 	return 0;
@@ -593,7 +640,9 @@ size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 		copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
 		memcpy_to_page(v.bv_page, v.bv_offset,
 			       (from += v.bv_len) - v.bv_len, v.bv_len),
-		memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
+		memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+		memcpy_to_page(v.bv_page, v.bv_offset,
+			       (from += v.bv_len) - v.bv_len, v.bv_len)
 	)
 
 	return bytes;
@@ -708,6 +757,15 @@ size_t _copy_to_iter_mcsafe(const void *addr, size_t bytes, struct iov_iter *i)
 			bytes = curr_addr - s_addr - rem;
 			return bytes;
 		}
+		}),
+		({
+		rem = memcpy_mcsafe_to_page(v.bv_page, v.bv_offset,
+                               (from += v.bv_len) - v.bv_len, v.bv_len);
+		if (rem) {
+			curr_addr = (unsigned long) from;
+			bytes = curr_addr - s_addr - rem;
+			return bytes;
+		}
 		})
 	)
 
@@ -729,7 +787,9 @@ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 		copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
 		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
-		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 
 	return bytes;
@@ -755,7 +815,9 @@ bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
 		0;}),
 		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
-		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 
 	iov_iter_advance(i, bytes);
@@ -775,7 +837,9 @@ size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 					 v.iov_base, v.iov_len),
 		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
-		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 
 	return bytes;
@@ -810,7 +874,9 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 		memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
 		memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base,
-			v.iov_len)
+			v.iov_len),
+		memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 
 	return bytes;
@@ -834,7 +900,9 @@ bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
 		0;}),
 		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
-		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+		memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 
 	iov_iter_advance(i, bytes);
@@ -860,7 +928,8 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
 		return 0;
 	switch (iov_iter_type(i)) {
 	case ITER_BVEC:
-	case ITER_KVEC: {
+	case ITER_KVEC:
+	case ITER_MAPPING: {
 		void *kaddr = kmap_atomic(page);
 		size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
 		kunmap_atomic(kaddr);
@@ -870,6 +939,8 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
 		return copy_page_to_iter_iovec(page, offset, bytes, i);
 	case ITER_PIPE:
 		return copy_page_to_iter_pipe(page, offset, bytes, i);
+	case ITER_DISCARD:
+		return bytes;
 	}
 	BUG();
 }
@@ -882,7 +953,9 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
 		return 0;
 	switch (iov_iter_type(i)) {
 	case ITER_PIPE:
+	case ITER_DISCARD:
 		break;
+	case ITER_MAPPING:
 	case ITER_BVEC:
 	case ITER_KVEC: {
 		void *kaddr = kmap_atomic(page);
@@ -930,7 +1003,8 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 	iterate_and_advance(i, bytes, v,
 		clear_user(v.iov_base, v.iov_len),
 		memzero_page(v.bv_page, v.bv_offset, v.bv_len),
-		memset(v.iov_base, 0, v.iov_len)
+		memset(v.iov_base, 0, v.iov_len),
+		memzero_page(v.bv_page, v.bv_offset, v.bv_len)
 	)
 
 	return bytes;
@@ -945,7 +1019,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 		kunmap_atomic(kaddr);
 		return 0;
 	}
-	if (unlikely(iov_iter_is_pipe(i))) {
+	if (unlikely(iov_iter_is_pipe(i) || iov_iter_type(i) == ITER_DISCARD)) {
 		kunmap_atomic(kaddr);
 		WARN_ON(1);
 		return 0;
@@ -954,7 +1028,9 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 		copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
 		memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
 				 v.bv_offset, v.bv_len),
-		memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+		memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+		memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
+				 v.bv_offset, v.bv_len)
 	)
 	kunmap_atomic(kaddr);
 	return bytes;
@@ -1016,7 +1092,14 @@ void iov_iter_advance(struct iov_iter *i, size_t size)
 	case ITER_IOVEC:
 	case ITER_KVEC:
 	case ITER_BVEC:
-		iterate_and_advance(i, size, v, 0, 0, 0);
+		iterate_and_advance(i, size, v, 0, 0, 0, 0);
+		return;
+	case ITER_MAPPING:
+		/* We really don't want to fetch pages is we can avoid it */
+		i->iov_offset += size;
+		/* Fall through */
+	case ITER_DISCARD:
+		i->count -= size;
 		return;
 	}
 	BUG();
@@ -1060,6 +1143,14 @@ void iov_iter_revert(struct iov_iter *i, size_t unroll)
 	}
 	unroll -= i->iov_offset;
 	switch (iov_iter_type(i)) {
+	case ITER_MAPPING:
+		BUG(); /* We should never go beyond the start of the mapping
+			* since iov_offset includes that page number as well as
+			* the in-page offset.
+			*/
+	case ITER_DISCARD:
+		i->iov_offset = 0;
+		return;
 	case ITER_BVEC: {
 		const struct bio_vec *bvec = i->bvec;
 		while (1) {
@@ -1103,6 +1194,8 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
 		return i->count;
 	switch (iov_iter_type(i)) {
 	case ITER_PIPE:
+	case ITER_DISCARD:
+	case ITER_MAPPING:
 		return i->count;	// it is a silly place, anyway
 	case ITER_BVEC:
 		return min_t(size_t, i->count, i->bvec->bv_len - i->iov_offset);
@@ -1158,6 +1251,52 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
 }
 EXPORT_SYMBOL(iov_iter_pipe);
 
+/**
+ * iov_iter_mapping - Initialise an I/O iterator to use the pages in a mapping
+ * @i: The iterator to initialise.
+ * @direction: The direction of the transfer.
+ * @mapping: The mapping to access.
+ * @start: The start file position.
+ * @count: The size of the I/O buffer in bytes.
+ *
+ * Set up an I/O iterator to either draw data out of the pages attached to an
+ * inode or to inject data into those pages.  The pages *must* be prevented
+ * from evaporation, either by taking a ref on them or locking them by the
+ * caller.
+ */
+void iov_iter_mapping(struct iov_iter *i, unsigned int direction,
+		      struct address_space *mapping,
+		      loff_t start, size_t count)
+{
+	BUG_ON(direction & ~1);
+	i->iter_dir = direction;
+	i->iter_type = ITER_MAPPING;
+	i->mapping = mapping;
+	i->count = count;
+	i->iov_offset = start;
+	i->page_done = NULL;
+}
+EXPORT_SYMBOL(iov_iter_mapping);
+
+/**
+ * iov_iter_discard - Initialise an I/O iterator that discards data
+ * @i: The iterator to initialise.
+ * @direction: The direction of the transfer.
+ * @count: The size of the I/O buffer in bytes.
+ *
+ * Set up an I/O iterator that just discards everything that's written to it.
+ * It's only available as a READ iterator.
+ */
+void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
+{
+	BUG_ON(direction != READ);
+	i->iter_dir = READ;
+	i->iter_type = ITER_DISCARD;
+	i->count = count;
+	i->iov_offset = 0;
+}
+EXPORT_SYMBOL(iov_iter_discard);
+
 unsigned long iov_iter_alignment(const struct iov_iter *i)
 {
 	unsigned long res = 0;
@@ -1171,7 +1310,8 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 	iterate_all_kinds(i, size, v,
 		(res |= (unsigned long)v.iov_base | v.iov_len, 0),
 		res |= v.bv_offset | v.bv_len,
-		res |= (unsigned long)v.iov_base | v.iov_len
+		res |= (unsigned long)v.iov_base | v.iov_len,
+		res |= v.bv_offset | v.bv_len
 	)
 	return res;
 }
@@ -1182,7 +1322,7 @@ unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
 	unsigned long res = 0;
 	size_t size = i->count;
 
-	if (unlikely(iov_iter_is_pipe(i))) {
+	if (unlikely(iov_iter_is_pipe(i) || iov_iter_type(i) == ITER_DISCARD)) {
 		WARN_ON(1);
 		return ~0U;
 	}
@@ -1193,7 +1333,9 @@ unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
 		(res |= (!res ? 0 : (unsigned long)v.bv_offset) |
 			(size != v.bv_len ? size : 0)),
 		(res |= (!res ? 0 : (unsigned long)v.iov_base) |
-			(size != v.iov_len ? size : 0))
+			(size != v.iov_len ? size : 0)),
+		(res |= (!res ? 0 : (unsigned long)v.bv_offset) |
+			(size != v.bv_len ? size : 0))
 		);
 	return res;
 }
@@ -1243,6 +1385,43 @@ static ssize_t pipe_get_pages(struct iov_iter *i,
 	return __pipe_get_pages(i, min(maxsize, capacity), pages, idx, start);
 }
 
+static ssize_t iter_mapping_get_pages(struct iov_iter *i,
+				      struct page **pages, size_t maxsize,
+				      unsigned maxpages, size_t *start)
+{
+	unsigned nr, offset;
+	pgoff_t index, count;
+	size_t size = maxsize;
+
+	if (!size || !maxpages)
+		return 0;
+
+	index = i->iov_offset >> PAGE_SHIFT;
+	offset = i->iov_offset & ~PAGE_MASK;
+	*start = offset;
+
+	count = 1;
+	if (size > PAGE_SIZE - offset) {
+		size -= PAGE_SIZE - offset;
+		count += size >> PAGE_SHIFT;
+		size &= ~PAGE_MASK;
+		if (size)
+			count++;
+	}
+
+	if (count > maxpages)
+		count = maxpages;
+
+	nr = find_get_pages_contig(i->mapping, index, count, pages);
+	if (nr == count)
+		return maxsize;
+	if (nr == 0)
+		return 0;
+	if (nr == 1)
+		return PAGE_SIZE - offset;
+	return (PAGE_SIZE - offset) + count * PAGE_SIZE;
+}
+
 ssize_t iov_iter_get_pages(struct iov_iter *i,
 		   struct page **pages, size_t maxsize, unsigned maxpages,
 		   size_t *start)
@@ -1253,6 +1432,9 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 	switch (iov_iter_type(i)) {
 	case ITER_PIPE:
 		return pipe_get_pages(i, pages, maxsize, maxpages, start);
+	case ITER_MAPPING:
+		return iter_mapping_get_pages(i, pages, maxsize, maxpages, start);
+	case ITER_DISCARD:
 	case ITER_KVEC:
 		return -EFAULT;
 	case ITER_IOVEC:
@@ -1279,9 +1461,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
 		*start = v.bv_offset;
 		get_page(*pages = v.bv_page);
 		return v.bv_len;
-	}),({
-		return -EFAULT;
-	})
+	}), 0, 0
 	)
 	return 0;
 }
@@ -1326,6 +1506,48 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
 	return n;
 }
 
+static ssize_t iter_mapping_get_pages_alloc(struct iov_iter *i,
+					    struct page ***pages, size_t maxsize,
+					    size_t *start)
+{
+	struct page **p;
+	unsigned nr, offset;
+	pgoff_t index, count;
+	size_t size = maxsize;
+
+	if (!size)
+		return 0;
+
+	index = i->iov_offset >> PAGE_SHIFT;
+	offset = i->iov_offset & ~PAGE_MASK;
+	*start = offset;
+
+	count = 1;
+	if (size > PAGE_SIZE - offset) {
+		size -= PAGE_SIZE - offset;
+		count += size >> PAGE_SHIFT;
+		size &= ~PAGE_MASK;
+		if (size)
+			count++;
+	}
+
+	p = get_pages_array(count);
+	if (!p)
+		return -ENOMEM;
+	*pages = p;
+
+	nr = find_get_pages_contig(i->mapping, index, count, p);
+	if (nr == count)
+		return maxsize;
+	if (nr == 0) {
+		kvfree(p);
+		return 0;
+	}
+	if (nr == 1)
+		return PAGE_SIZE - offset;
+	return (PAGE_SIZE - offset) + count * PAGE_SIZE;
+}
+
 ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 		   struct page ***pages, size_t maxsize,
 		   size_t *start)
@@ -1338,6 +1560,9 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 	switch (iov_iter_type(i)) {
 	case ITER_PIPE:
 		return pipe_get_pages_alloc(i, pages, maxsize, start);
+	case ITER_MAPPING:
+		return iter_mapping_get_pages_alloc(i, pages, maxsize, start);
+	case ITER_DISCARD:
 	case ITER_KVEC:
 		return -EFAULT;
 	case ITER_IOVEC:
@@ -1371,9 +1596,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
 			return -ENOMEM;
 		get_page(*p = v.bv_page);
 		return v.bv_len;
-	}),({
-		return -EFAULT;
-	})
+	}), 0, 0
 	)
 	return 0;
 }
@@ -1386,7 +1609,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(iov_iter_is_pipe(i))) {
+	if (unlikely(iov_iter_is_pipe(i) || iov_iter_type(i) == ITER_DISCARD)) {
 		WARN_ON(1);
 		return 0;
 	}
@@ -1414,6 +1637,14 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
 						 v.iov_len, 0);
 		sum = csum_block_add(sum, next, off);
 		off += v.iov_len;
+	}), ({
+		char *p = kmap_atomic(v.bv_page);
+		next = csum_partial_copy_nocheck(p + v.bv_offset,
+						 (to += v.bv_len) - v.bv_len,
+						 v.bv_len, 0);
+		kunmap_atomic(p);
+		sum = csum_block_add(sum, next, off);
+		off += v.bv_len;
 	})
 	)
 	*csum = sum;
@@ -1428,7 +1659,7 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(iov_iter_is_pipe(i))) {
+	if (unlikely(iov_iter_is_pipe(i) || iov_iter_type(i) == ITER_DISCARD)) {
 		WARN_ON(1);
 		return false;
 	}
@@ -1458,6 +1689,14 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
 						 v.iov_len, 0);
 		sum = csum_block_add(sum, next, off);
 		off += v.iov_len;
+	}), ({
+		char *p = kmap_atomic(v.bv_page);
+		next = csum_partial_copy_nocheck(p + v.bv_offset,
+						 (to += v.bv_len) - v.bv_len,
+						 v.bv_len, 0);
+		kunmap_atomic(p);
+		sum = csum_block_add(sum, next, off);
+		off += v.bv_len;
 	})
 	)
 	*csum = sum;
@@ -1473,7 +1712,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
 	__wsum sum, next;
 	size_t off = 0;
 	sum = *csum;
-	if (unlikely(iov_iter_is_pipe(i))) {
+	if (unlikely(iov_iter_is_pipe(i) || iov_iter_type(i) == ITER_DISCARD)) {
 		WARN_ON(1);	/* for now */
 		return 0;
 	}
@@ -1501,6 +1740,14 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
 						 v.iov_len, 0);
 		sum = csum_block_add(sum, next, off);
 		off += v.iov_len;
+	}), ({
+		char *p = kmap_atomic(v.bv_page);
+		next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
+						 p + v.bv_offset,
+						 v.bv_len, 0);
+		kunmap_atomic(p);
+		sum = csum_block_add(sum, next, off);
+		off += v.bv_len;
 	})
 	)
 	*csum = sum;
@@ -1516,7 +1763,8 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
 	if (!size)
 		return 0;
 
-	if (unlikely(iov_iter_is_pipe(i))) {
+	switch (iov_iter_type(i)) {
+	case ITER_PIPE: {
 		struct pipe_inode_info *pipe = i->pipe;
 		size_t off;
 		int idx;
@@ -1529,24 +1777,47 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
 		npages = ((pipe->curbuf - idx - 1) & (pipe->buffers - 1)) + 1;
 		if (npages >= maxpages)
 			return maxpages;
-	} else iterate_all_kinds(i, size, v, ({
-		unsigned long p = (unsigned long)v.iov_base;
-		npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
-			- p / PAGE_SIZE;
-		if (npages >= maxpages)
-			return maxpages;
-	0;}),({
-		npages++;
-		if (npages >= maxpages)
-			return maxpages;
-	}),({
-		unsigned long p = (unsigned long)v.iov_base;
-		npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
-			- p / PAGE_SIZE;
+	}
+	case ITER_MAPPING: {
+		unsigned offset;
+
+		offset = i->iov_offset & ~PAGE_MASK;
+
+		npages = 1;
+		if (size > PAGE_SIZE - offset) {
+			size -= PAGE_SIZE - offset;
+			npages += size >> PAGE_SHIFT;
+			size &= ~PAGE_MASK;
+			if (size)
+				npages++;
+		}
 		if (npages >= maxpages)
 			return maxpages;
-	})
-	)
+	}
+	case ITER_DISCARD:
+		return 0;
+
+	default:
+		iterate_all_kinds(i, size, v, ({
+			unsigned long p = (unsigned long)v.iov_base;
+			npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+				- p / PAGE_SIZE;
+			if (npages >= maxpages)
+				return maxpages;
+		0;}),({
+			npages++;
+			if (npages >= maxpages)
+				return maxpages;
+		}),({
+			unsigned long p = (unsigned long)v.iov_base;
+			npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+				- p / PAGE_SIZE;
+			if (npages >= maxpages)
+				return maxpages;
+		}),
+		0
+		)
+	}
 	return npages;
 }
 EXPORT_SYMBOL(iov_iter_npages);
@@ -1567,6 +1838,9 @@ const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags)
 		return new->iov = kmemdup(new->iov,
 				   new->nr_segs * sizeof(struct iovec),
 				   flags);
+	case ITER_MAPPING:
+	case ITER_DISCARD:
+		return NULL;
 	}
 
 	WARN_ON(1);
@@ -1670,7 +1944,12 @@ int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
 		kunmap(v.bv_page);
 		err;}), ({
 		w = v;
-		err = f(&w, context);})
+		err = f(&w, context);}), ({
+		w.iov_base = kmap(v.bv_page) + v.bv_offset;
+		w.iov_len = v.bv_len;
+		err = f(&w, context);
+		kunmap(v.bv_page);
+		err;})
 	)
 	return err;
 }

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 05/10] afs: Better tracing of protocol errors
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (3 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 04/10] iov_iter: Add mapping and discard iterator types David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data() David Howells
                   ` (4 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cmservice.c         |    6 ++
 fs/afs/fsclient.c          |  117 +++++++++++++++++++++++++++-----------------
 fs/afs/inode.c             |    2 -
 fs/afs/internal.h          |    2 -
 fs/afs/rxrpc.c             |    5 +-
 fs/afs/vlclient.c          |   30 ++++++++---
 include/trace/events/afs.h |   54 +++++++++++++++++---
 7 files changed, 146 insertions(+), 70 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 9e51d6fe7e8f..58f79301a716 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -189,7 +189,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->count = ntohl(call->tmp);
 		_debug("FID count: %u", call->count);
 		if (call->count > AFSCBMAX)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_cb_fid_count);
 
 		call->buffer = kmalloc(array3_size(call->count, 3, 4),
 				       GFP_KERNEL);
@@ -234,7 +235,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->count2 = ntohl(call->tmp);
 		_debug("CB count: %u", call->count2);
 		if (call->count2 != call->count && call->count2 != 0)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_cb_count);
 		call->offset = 0;
 		call->unmarshall++;
 
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 50929cb91732..d9a5815945dc 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -233,7 +233,7 @@ static int xdr_decode_AFSFetchStatus(struct afs_call *call,
 
 bad:
 	xdr_dump_bad(*_bp);
-	return afs_protocol_error(call, -EBADMSG);
+	return afs_protocol_error(call, -EBADMSG, afs_eproto_bad_status);
 }
 
 /*
@@ -399,9 +399,10 @@ static int afs_deliver_fs_fetch_status_vnode(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	xdr_decode_AFSCallBack(call, vnode, &bp);
 	if (call->reply[1])
 		xdr_decode_AFSVolSync(&bp, call->reply[1]);
@@ -580,9 +581,10 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 			return ret;
 
 		bp = call->buffer;
-		if (afs_decode_status(call, &bp, &vnode->status, vnode,
-				      &vnode->status.data_version, req) < 0)
-			return afs_protocol_error(call, -EBADMSG);
+		ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+					&vnode->status.data_version, req);
+		if (ret < 0)
+			return ret;
 		xdr_decode_AFSCallBack(call, vnode, &bp);
 		if (call->reply[1])
 			xdr_decode_AFSVolSync(&bp, call->reply[1]);
@@ -733,10 +735,13 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
 	xdr_decode_AFSFid(&bp, call->reply[1]);
-	if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) < 0 ||
-	    afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL);
+	if (ret < 0)
+		return ret;
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	xdr_decode_AFSCallBack_raw(&bp, call->reply[3]);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
@@ -839,9 +844,10 @@ static int afs_deliver_fs_remove(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -929,10 +935,13 @@ static int afs_deliver_fs_link(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &vnode->status, vnode, NULL, NULL) < 0 ||
-	    afs_decode_status(call, &bp, &dvnode->status, dvnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode, NULL, NULL);
+	if (ret < 0)
+		return ret;
+	ret = afs_decode_status(call, &bp, &dvnode->status, dvnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -1016,10 +1025,13 @@ static int afs_deliver_fs_symlink(struct afs_call *call)
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
 	xdr_decode_AFSFid(&bp, call->reply[1]);
-	if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) ||
-	    afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL);
+	if (ret < 0)
+		return ret;
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -1122,13 +1134,16 @@ static int afs_deliver_fs_rename(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &orig_dvnode->status, orig_dvnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
-	if (new_dvnode != orig_dvnode &&
-	    afs_decode_status(call, &bp, &new_dvnode->status, new_dvnode,
-			      &call->expected_version_2, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &orig_dvnode->status, orig_dvnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
+	if (new_dvnode != orig_dvnode) {
+		ret = afs_decode_status(call, &bp, &new_dvnode->status, new_dvnode,
+					&call->expected_version_2, NULL);
+		if (ret < 0)
+			return ret;
+	}
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -1231,9 +1246,10 @@ static int afs_deliver_fs_store_data(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	afs_pages_written_back(vnode, call);
@@ -1407,9 +1423,10 @@ static int afs_deliver_fs_store_status(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	if (afs_decode_status(call, &bp, &vnode->status, vnode,
-			      &call->expected_version, NULL) < 0)
-		return afs_protocol_error(call, -EBADMSG);
+	ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -1612,7 +1629,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->count = ntohl(call->tmp);
 		_debug("volname length: %u", call->count);
 		if (call->count >= AFSNAMEMAX)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_volname_len);
 		call->offset = 0;
 		call->unmarshall++;
 
@@ -1659,7 +1677,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->count = ntohl(call->tmp);
 		_debug("offline msg length: %u", call->count);
 		if (call->count >= AFSNAMEMAX)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_offline_msg_len);
 		call->offset = 0;
 		call->unmarshall++;
 
@@ -1706,7 +1725,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->count = ntohl(call->tmp);
 		_debug("motd length: %u", call->count);
 		if (call->count >= AFSNAMEMAX)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_motd_len);
 		call->offset = 0;
 		call->unmarshall++;
 
@@ -2109,8 +2129,10 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call)
 
 	/* unmarshall the reply once we've received all of it */
 	bp = call->buffer;
-	afs_decode_status(call, &bp, status, vnode,
-			  &call->expected_version, NULL);
+	ret = afs_decode_status(call, &bp, status, vnode,
+				&call->expected_version, NULL);
+	if (ret < 0)
+		return ret;
 	callback[call->count].version	= ntohl(bp[0]);
 	callback[call->count].expiry	= ntohl(bp[1]);
 	callback[call->count].type	= ntohl(bp[2]);
@@ -2206,7 +2228,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		tmp = ntohl(call->tmp);
 		_debug("status count: %u/%u", tmp, call->count2);
 		if (tmp != call->count2)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_ibulkst_count);
 
 		call->count = 0;
 		call->unmarshall++;
@@ -2221,10 +2244,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 		bp = call->buffer;
 		statuses = call->reply[1];
-		if (afs_decode_status(call, &bp, &statuses[call->count],
-				      call->count == 0 ? vnode : NULL,
-				      NULL, NULL) < 0)
-			return afs_protocol_error(call, -EBADMSG);
+		ret = afs_decode_status(call, &bp, &statuses[call->count],
+					call->count == 0 ? vnode : NULL,
+					NULL, NULL);
+		if (ret < 0)
+			return ret;
 
 		call->count++;
 		if (call->count < call->count2)
@@ -2244,7 +2268,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		tmp = ntohl(call->tmp);
 		_debug("CB count: %u", tmp);
 		if (tmp != call->count2)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_ibulkst_cb_count);
 		call->count = 0;
 		call->unmarshall++;
 	more_cbs:
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 479b7fdda124..ab4e7a15c205 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -82,7 +82,7 @@ static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key)
 	default:
 		printk("kAFS: AFS vnode with undefined type\n");
 		read_sequnlock_excl(&vnode->cb_lock);
-		return afs_protocol_error(NULL, -EBADMSG);
+		return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type);
 	}
 
 	inode->i_blocks		= 0;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 35aa4bd79145..852f68a400b8 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -928,7 +928,7 @@ extern void afs_flat_call_destructor(struct afs_call *);
 extern void afs_send_empty_reply(struct afs_call *);
 extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
 extern int afs_extract_data(struct afs_call *, void *, size_t, bool);
-extern int afs_protocol_error(struct afs_call *, int);
+extern int afs_protocol_error(struct afs_call *, int, enum afs_eproto_cause);
 
 static inline int afs_transfer_reply(struct afs_call *call)
 {
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 55441af2de53..37811901a5c9 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -941,8 +941,9 @@ int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 /*
  * Log protocol error production.
  */
-noinline int afs_protocol_error(struct afs_call *call, int error)
+noinline int afs_protocol_error(struct afs_call *call, int error,
+				enum afs_eproto_cause cause)
 {
-	trace_afs_protocol_error(call, error, __builtin_return_address(0));
+	trace_afs_protocol_error(call, error, cause);
 	return error;
 }
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index c3b740813fc7..d0f95c4ab05e 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -451,7 +451,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		call->count2	= ntohl(*bp); /* Type or next count */
 
 		if (call->count > YFS_MAXENDPOINTS)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_fsendpt_num);
 
 		alist = afs_alloc_addrlist(call->count, FS_SERVICE, AFS_FS_PORT);
 		if (!alist)
@@ -475,7 +476,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			size = sizeof(__be32) * (1 + 4 + 1);
 			break;
 		default:
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_fsendpt_type);
 		}
 
 		size += sizeof(__be32);
@@ -488,18 +490,21 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
-				return afs_protocol_error(call, -EBADMSG);
+				return afs_protocol_error(call, -EBADMSG,
+							  afs_eproto_yvl_fsendpt4_len);
 			afs_merge_fs_addr4(alist, bp[1], ntohl(bp[2]));
 			bp += 3;
 			break;
 		case YFS_ENDPOINT_IPV6:
 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
-				return afs_protocol_error(call, -EBADMSG);
+				return afs_protocol_error(call, -EBADMSG,
+							  afs_eproto_yvl_fsendpt6_len);
 			afs_merge_fs_addr6(alist, bp + 1, ntohl(bp[5]));
 			bp += 6;
 			break;
 		default:
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_fsendpt_type);
 		}
 
 		/* Got either the type of the next entry or the count of
@@ -518,7 +523,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		if (!call->count)
 			goto end;
 		if (call->count > YFS_MAXENDPOINTS)
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_vlendpt_type);
 
 		call->unmarshall = 3;
 
@@ -546,7 +552,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			size = sizeof(__be32) * (1 + 4 + 1);
 			break;
 		default:
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_vlendpt_type);
 		}
 
 		if (call->count > 1)
@@ -559,16 +566,19 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
-				return afs_protocol_error(call, -EBADMSG);
+				return afs_protocol_error(call, -EBADMSG,
+							  afs_eproto_yvl_vlendpt4_len);
 			bp += 3;
 			break;
 		case YFS_ENDPOINT_IPV6:
 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
-				return afs_protocol_error(call, -EBADMSG);
+				return afs_protocol_error(call, -EBADMSG,
+							  afs_eproto_yvl_vlendpt6_len);
 			bp += 6;
 			break;
 		default:
-			return afs_protocol_error(call, -EBADMSG);
+			return afs_protocol_error(call, -EBADMSG,
+						  afs_eproto_yvl_vlendpt_type);
 		}
 
 		/* Got either the type of the next entry or the count of
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index d0a341bc4540..5c60ade2c7d8 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -84,6 +84,25 @@ enum afs_edit_dir_reason {
 	afs_edit_dir_for_unlink,
 };
 
+enum afs_eproto_cause {
+	afs_eproto_bad_status,
+	afs_eproto_cb_count,
+	afs_eproto_cb_fid_count,
+	afs_eproto_file_type,
+	afs_eproto_ibulkst_cb_count,
+	afs_eproto_ibulkst_count,
+	afs_eproto_motd_len,
+	afs_eproto_offline_msg_len,
+	afs_eproto_volname_len,
+	afs_eproto_yvl_fsendpt4_len,
+	afs_eproto_yvl_fsendpt6_len,
+	afs_eproto_yvl_fsendpt_num,
+	afs_eproto_yvl_fsendpt_type,
+	afs_eproto_yvl_vlendpt4_len,
+	afs_eproto_yvl_vlendpt6_len,
+	afs_eproto_yvl_vlendpt_type,
+};
+
 #endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */
 
 /*
@@ -146,6 +165,24 @@ enum afs_edit_dir_reason {
 	EM(afs_edit_dir_for_symlink,		"Symlnk") \
 	E_(afs_edit_dir_for_unlink,		"Unlink")
 
+#define afs_eproto_causes			\
+	EM(afs_eproto_bad_status,	"BadStatus") \
+	EM(afs_eproto_cb_count,		"CbCount") \
+	EM(afs_eproto_cb_fid_count,	"CbFidCount") \
+	EM(afs_eproto_file_type,	"FileTYpe") \
+	EM(afs_eproto_ibulkst_cb_count,	"IBS.CbCount") \
+	EM(afs_eproto_ibulkst_count,	"IBS.FidCount") \
+	EM(afs_eproto_motd_len,		"MotdLen") \
+	EM(afs_eproto_offline_msg_len,	"OfflineMsgLen") \
+	EM(afs_eproto_volname_len,	"VolNameLen") \
+	EM(afs_eproto_yvl_fsendpt4_len,	"YVL.FsEnd4Len") \
+	EM(afs_eproto_yvl_fsendpt6_len,	"YVL.FsEnd6Len") \
+	EM(afs_eproto_yvl_fsendpt_num,	"YVL.FsEndCount") \
+	EM(afs_eproto_yvl_fsendpt_type,	"YVL.FsEndType") \
+	EM(afs_eproto_yvl_vlendpt4_len,	"YVL.VlEnd4Len") \
+	EM(afs_eproto_yvl_vlendpt6_len,	"YVL.VlEnd6Len") \
+	E_(afs_eproto_yvl_vlendpt_type,	"YVL.VlEndType")
+
 
 /*
  * Export enum symbols via userspace.
@@ -555,24 +592,25 @@ TRACE_EVENT(afs_edit_dir,
 	    );
 
 TRACE_EVENT(afs_protocol_error,
-	    TP_PROTO(struct afs_call *call, int error, const void *where),
+	    TP_PROTO(struct afs_call *call, int error, enum afs_eproto_cause cause),
 
-	    TP_ARGS(call, error, where),
+	    TP_ARGS(call, error, cause),
 
 	    TP_STRUCT__entry(
-		    __field(unsigned int,	call		)
-		    __field(int,		error		)
-		    __field(const void *,	where		)
+		    __field(unsigned int,		call		)
+		    __field(int,			error		)
+		    __field(enum afs_eproto_cause,	cause		)
 			     ),
 
 	    TP_fast_assign(
 		    __entry->call = call ? call->debug_id : 0;
 		    __entry->error = error;
-		    __entry->where = where;
+		    __entry->cause = cause;
 			   ),
 
-	    TP_printk("c=%08x r=%d sp=%pSR",
-		      __entry->call, __entry->error, __entry->where)
+	    TP_printk("c=%08x r=%d %s",
+		      __entry->call, __entry->error,
+		      __print_symbolic(__entry->cause, afs_eproto_causes))
 	    );
 
 TRACE_EVENT(afs_cm_no_server,

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data()
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (4 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 05/10] afs: Better tracing of protocol errors David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 07/10] afs: Use ITER_MAPPING for writing David Howells
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.

Instead:

 (1) Put an iterator in the afs_call struct.

 (2) Set the iterator for each marshalling stage to load data into the
     appropriate places.  A number of convenience functions are provided to
     this end (eg. afs_extract_to_buf()).

     This iterator is then passed to afs_extract_data().

 (3) Use the new ITER_MAPPING iterator when reading data to load directly
     into the inode's pages without needing to create a list of them.  This
     comes with a page-done callback that can be used to unlock pages as
     they are filled.

 (4) Use the new ITER_DISCARD iterator to discard any excess data provided
     by FetchData.

This will allow O_DIRECT calls to be supported in future patches.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cmservice.c         |   40 +++----
 fs/afs/dir.c               |  193 +++++++++++++++++++++++-----------
 fs/afs/file.c              |  200 +++++++++++++++++++++++------------
 fs/afs/fsclient.c          |  252 ++++++++++++--------------------------------
 fs/afs/internal.h          |   52 ++++++++-
 fs/afs/rxrpc.c             |   41 ++-----
 fs/afs/vlclient.c          |  104 ++++++++----------
 fs/afs/write.c             |    8 +
 include/linux/fscache.h    |   31 +++++
 include/trace/events/afs.h |   22 ++--
 10 files changed, 502 insertions(+), 441 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 58f79301a716..4db62ae8dc1a 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -176,13 +176,13 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* extract the FID array and its count in two steps */
 	case 1:
 		_debug("extract FID count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -196,13 +196,12 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 				       GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
-		call->offset = 0;
+		afs_extract_to_buf(call, call->count * 3 * 4);
 		call->unmarshall++;
 
 	case 2:
 		_debug("extract FID array");
-		ret = afs_extract_data(call, call->buffer,
-				       call->count * 3 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -222,13 +221,13 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 			cb->cb.type	= AFSCM_CB_UNTYPED;
 		}
 
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* extract the callback array and its count in two steps */
 	case 3:
 		_debug("extract CB count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -237,13 +236,12 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		if (call->count2 != call->count && call->count2 != 0)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_cb_count);
-		call->offset = 0;
+		afs_extract_to_buf(call, call->count2 * 3 * 4);
 		call->unmarshall++;
 
 	case 4:
 		_debug("extract CB array");
-		ret = afs_extract_data(call, call->buffer,
-				       call->count2 * 3 * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -256,7 +254,6 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 			cb->cb.type	= ntohl(*bp++);
 		}
 
-		call->offset = 0;
 		call->unmarshall++;
 	case 5:
 		break;
@@ -303,7 +300,8 @@ static int afs_deliver_cb_init_call_back_state(struct afs_call *call)
 
 	rxrpc_kernel_get_peer(call->net->socket, call->rxcall, &srx);
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
@@ -332,16 +330,15 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
+		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 1:
 		_debug("extract UUID");
-		ret = afs_extract_data(call, call->buffer,
-				       11 * sizeof(__be32), false);
+		ret = afs_extract_data(call, false);
 		switch (ret) {
 		case 0:		break;
 		case -EAGAIN:	return 0;
@@ -364,7 +361,6 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 		for (loop = 0; loop < 6; loop++)
 			r->node[loop] = ntohl(b[loop + 5]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 2:
@@ -407,7 +403,8 @@ static int afs_deliver_cb_probe(struct afs_call *call)
 
 	_enter("");
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
@@ -455,16 +452,15 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
+		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 1:
 		_debug("extract UUID");
-		ret = afs_extract_data(call, call->buffer,
-				       11 * sizeof(__be32), false);
+		ret = afs_extract_data(call, false);
 		switch (ret) {
 		case 0:		break;
 		case -EAGAIN:	return 0;
@@ -487,7 +483,6 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 		for (loop = 0; loop < 6; loop++)
 			r->node[loop] = ntohl(b[loop + 5]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 2:
@@ -572,7 +567,8 @@ static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
 
 	_enter("");
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 7d623008157f..1357a10804bb 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -105,6 +105,41 @@ struct afs_lookup_cookie {
 	struct afs_fid		fids[50];
 };
 
+/*
+ * Drop the refs that we're holding on the pages we were reading into.  We've
+ * got refs on the first nr_pages pages.
+ */
+static void afs_dir_read_cleanup(struct afs_read *req)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = req->iter.mapping;
+	struct page *page;
+	pgoff_t index = req->pos >> PAGE_SHIFT;
+	void __rcu **slot;
+
+	if (unlikely(!req->nr_pages))
+		return;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page))
+			continue;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page->mapping != req->iter.mapping);
+		BUG_ON(page_to_pgoff(page) != iter.index);
+
+		put_page(page);
+		req->nr_pages--;
+		if (req->nr_pages == 0)
+			break;
+	}
+
+	rcu_read_unlock();
+}
+
 /*
  * check that a directory page is valid
  */
@@ -130,7 +165,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 	qty /= sizeof(union afs_xdr_dir_block);
 
 	/* check them */
-	dbuf = kmap(page);
+	dbuf = kmap_atomic(page);
 	for (tmp = 0; tmp < qty; tmp++) {
 		if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
 			printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
@@ -148,7 +183,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 		((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
 	}
 
-	kunmap(page);
+	kunmap_atomic(dbuf);
 
 checked:
 	afs_stat_v(dvnode, n_read_dir);
@@ -158,6 +193,46 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 	return false;
 }
 
+/*
+ * Check all the pages in a directory.  All the pages are held pinned.
+ */
+static int afs_dir_check(struct afs_vnode *dvnode, unsigned int nr_pages,
+			 loff_t i_size)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = dvnode->vfs_inode.i_mapping;
+	struct page *page;
+	void __rcu **slot;
+	int ret = 0;
+
+	if (unlikely(!nr_pages))
+		return 0;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, 0) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page)) {
+			pr_warn("kAFS: Missing page in dircheck\n");
+			ret = -EIO;
+			break;
+		}
+		if (page->index >= nr_pages)
+			break;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page->mapping != mapping);
+		BUG_ON(page_to_pgoff(page) != iter.index);
+
+		ret = afs_dir_check_page(dvnode, page, i_size);
+		if (ret < 0)
+			break;
+	}
+
+	rcu_read_unlock();
+	return ret;
+}
+
 /*
  * open an AFS directory file
  */
@@ -184,56 +259,49 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 {
 	struct afs_read *req;
 	loff_t i_size;
-	int nr_pages, nr_inline, i, n;
-	int ret = -ENOMEM;
+	int nr_pages, i, n;
+	int ret;
+
+	_enter("");
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	refcount_set(&req->usage, 1);
+	req->cleanup = afs_dir_read_cleanup;
 
-retry:
+expand:
 	i_size = i_size_read(&dvnode->vfs_inode);
+	ret = -EIO;
 	if (i_size < 2048)
-		return ERR_PTR(-EIO);
+		goto error;
+	ret = -EFBIG;
 	if (i_size > 2048 * 1024)
-		return ERR_PTR(-EFBIG);
-
-	_enter("%llu", i_size);
+		goto error;
 
-	/* Get a request record to hold the page list.  We want to hold it
-	 * inline if we can, but we don't want to make an order 1 allocation.
-	 */
 	nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
-	nr_inline = nr_pages;
-	if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
-		nr_inline = 0;
 
-	req = kzalloc(sizeof(*req) + sizeof(struct page *) * nr_inline,
-		      GFP_KERNEL);
-	if (!req)
-		return ERR_PTR(-ENOMEM);
-
-	refcount_set(&req->usage, 1);
-	req->nr_pages = nr_pages;
 	req->actual_len = i_size; /* May change */
 	req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
 	req->data_version = dvnode->status.data_version; /* May change */
-	if (nr_inline > 0) {
-		req->pages = req->array;
-	} else {
-		req->pages = kcalloc(nr_pages, sizeof(struct page *),
-				     GFP_KERNEL);
-		if (!req->pages)
-			goto error;
-	}
+	iov_iter_mapping(&req->iter, READ, dvnode->vfs_inode.i_mapping,
+			 0, i_size);
 
-	/* Get a list of all the pages that hold or will hold the directory
-	 * content.  We need to fill in any gaps that we might find where the
-	 * memory reclaimer has been at work.  If there are any gaps, we will
+	/* Fill in any gaps that we might find where the memory reclaimer has
+	 * been at work and pin all the pages.  If there are any gaps, we will
 	 * need to reread the entire directory contents.
 	 */
-	i = 0;
-	do {
+	i = req->nr_pages;
+	while (i < nr_pages) {
+		struct page *pages[8], *page;
+
 		n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
-					  req->nr_pages - i,
-					  req->pages + i);
-		_debug("find %u at %u/%u", n, i, req->nr_pages);
+					  min_t(unsigned int, nr_pages - i,
+						ARRAY_SIZE(pages)),
+					  pages);
+		_debug("find %u at %u/%u", n, i, nr_pages);
+
 		if (n == 0) {
 			gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
 
@@ -241,23 +309,25 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 				afs_stat_v(dvnode, n_inval);
 
 			ret = -ENOMEM;
-			req->pages[i] = __page_cache_alloc(gfp);
-			if (!req->pages[i])
+			page = __page_cache_alloc(gfp);
+			if (!page)
 				goto error;
-			ret = add_to_page_cache_lru(req->pages[i],
+			ret = add_to_page_cache_lru(page,
 						    dvnode->vfs_inode.i_mapping,
 						    i, gfp);
 			if (ret < 0)
 				goto error;
 
-			set_page_private(req->pages[i], 1);
-			SetPagePrivate(req->pages[i]);
-			unlock_page(req->pages[i]);
+			set_page_private(page, 1);
+			SetPagePrivate(page);
+			unlock_page(page);
+			req->nr_pages++;
 			i++;
 		} else {
+			req->nr_pages += n;
 			i += n;
 		}
-	} while (i < req->nr_pages);
+	}
 
 	/* If we're going to reload, we need to lock all the pages to prevent
 	 * races.
@@ -280,15 +350,18 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 
 		task_io_account_read(PAGE_SIZE * req->nr_pages);
 
-		if (req->len < req->file_size)
-			goto content_has_grown;
+		if (req->len < req->file_size) {
+			/* The content has grown, so we need to expand the
+			 * buffer.
+			 */
+			up_write(&dvnode->validate_lock);
+			goto expand;
+		}
 
 		/* Validate the data we just read. */
-		ret = -EIO;
-		for (i = 0; i < req->nr_pages; i++)
-			if (!afs_dir_check_page(dvnode, req->pages[i],
-						req->actual_len))
-				goto error_unlock;
+		ret = afs_dir_check(dvnode, req->nr_pages, req->actual_len);
+		if (ret < 0)
+			goto error_unlock;
 
 		// TODO: Trim excess pages
 
@@ -305,11 +378,6 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 	afs_put_read(req);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
-
-content_has_grown:
-	up_write(&dvnode->validate_lock);
-	afs_put_read(req);
-	goto retry;
 }
 
 /*
@@ -415,6 +483,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 	struct afs_read *req;
 	struct page *page;
 	unsigned blkoff, limit;
+	void __rcu **slot;
 	int ret;
 
 	_enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
@@ -438,9 +507,15 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 		blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
 
 		/* Fetch the appropriate page from the directory and re-add it
-		 * to the LRU.
+		 * to the LRU.  We have all the pages pinned with an extra ref.
 		 */
-		page = req->pages[blkoff / PAGE_SIZE];
+		rcu_read_lock();
+		page = NULL;
+		slot = radix_tree_lookup_slot(&dvnode->vfs_inode.i_mapping->i_pages,
+					      blkoff / PAGE_SIZE);
+		if (slot)
+			page = radix_tree_deref_slot(slot);
+		rcu_read_unlock();
 		if (!page) {
 			ret = -EIO;
 			break;
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 7d4f26198573..6d55dabccd79 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -148,7 +148,7 @@ int afs_open(struct inode *inode, struct file *file)
 
 	if (file->f_flags & O_TRUNC)
 		set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
-	
+
 	file->private_data = af;
 	_leave(" = 0");
 	return 0;
@@ -185,24 +185,80 @@ int afs_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+/*
+ * Make pages available as they're filled.  This function may not sleep.
+ */
+static void afs_readpages_page_done(const struct iov_iter *iter,
+				    const struct bio_vec *bv)
+{
+	struct page *page = bv->bv_page;
+	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+	struct afs_read *req = container_of(iter, struct afs_read, iter);
+
+	SetPageUptodate(page);
+
+	if (0 && afs_vnode_cache(vnode))
+		SetPageFsCache(page);
+	unlock_page(page);
+	put_page(page);
+	req->done_pages++;
+}
+
+/*
+ * Unlock the pages we were reading into.  We've got locks and refs on the
+ * first nr_pages pages.
+ */
+static void afs_file_read_cleanup(struct afs_read *req)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = req->iter.mapping;
+	struct page *page;
+	pgoff_t index = req->pos >> PAGE_SHIFT;
+	void **slot;
+
+	_enter("%lu,%u,%u,%llu",
+	       index, req->done_pages, req->nr_pages, iov_iter_count(&req->iter));
+
+	if (likely(req->done_pages >= req->nr_pages))
+		return;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page))
+			continue;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page != *slot);
+		BUG_ON(page->mapping != req->iter.mapping);
+		BUG_ON(page_to_pgoff(page) != iter.index);
+
+		if (req->error)
+			SetPageError(page);
+		unlock_page(page);
+		put_page(page);
+		req->done_pages++;
+		if (req->done_pages >= req->nr_pages)
+			break;
+	}
+
+	rcu_read_unlock();
+}
+
 /*
  * Dispose of a ref to a read record.
  */
 void afs_put_read(struct afs_read *req)
 {
-	int i;
-
 	if (refcount_dec_and_test(&req->usage)) {
-		for (i = 0; i < req->nr_pages; i++)
-			if (req->pages[i])
-				put_page(req->pages[i]);
-		if (req->pages != req->array)
-			kfree(req->pages);
+		if (req->cleanup)
+			req->cleanup(req);
 		kfree(req);
 	}
 }
 
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 /*
  * deal with notification that a page was read from the cache
  */
@@ -257,6 +313,22 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *de
 	return ret;
 }
 
+/*
+ * Clear the trailer after a short read.
+ */
+static void afs_clear_after_read(struct afs_vnode *vnode, struct afs_read *req,
+				 bool catch_page_done)
+{
+	if (req->actual_len >= req->len)
+		return;
+	iov_iter_mapping(&req->iter, READ, vnode->vfs_inode.i_mapping,
+			 req->pos + req->actual_len,
+			 req->len - req->actual_len);
+	if (catch_page_done)
+		req->iter.page_done = afs_readpages_page_done;
+	iov_iter_zero(req->len - req->actual_len, &req->iter);
+}
+
 /*
  * read page from file, directory or symlink, given a key to use
  */
@@ -277,7 +349,7 @@ int afs_page_filler(void *data, struct page *page)
 		goto error;
 
 	/* is it cached? */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	ret = fscache_read_or_alloc_page(vnode->cache,
 					 page,
 					 afs_file_readpage_read_complete,
@@ -301,8 +373,7 @@ int afs_page_filler(void *data, struct page *page)
 		_debug("cache said ENOBUFS");
 	default:
 	go_on:
-		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-			      GFP_KERNEL);
+		req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
 		if (!req)
 			goto enomem;
 
@@ -314,10 +385,11 @@ int afs_page_filler(void *data, struct page *page)
 		req->pos = (loff_t)page->index << PAGE_SHIFT;
 		req->len = PAGE_SIZE;
 		req->nr_pages = 1;
-		req->pages = req->array;
-		req->pages[0] = page;
 		get_page(page);
 
+		iov_iter_mapping(&req->iter, READ, page->mapping,
+				 (loff_t)page->index << PAGE_SHIFT, PAGE_SIZE);
+
 		/* read the contents of the file from the server into the
 		 * page */
 		ret = afs_fetch_data(vnode, key, req);
@@ -331,11 +403,6 @@ int afs_page_filler(void *data, struct page *page)
 				ret = -ESTALE;
 			}
 
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			BUG_ON(PageFsCache(page));
-
 			if (ret == -EINTR ||
 			    ret == -ENOMEM ||
 			    ret == -ERESTARTSYS ||
@@ -344,10 +411,11 @@ int afs_page_filler(void *data, struct page *page)
 			goto io_error;
 		}
 
+		afs_clear_after_read(vnode, req, false);
 		SetPageUptodate(page);
 
 		/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 		if (PageFsCache(page) &&
 		    fscache_write_page(vnode->cache, page, vnode->status.size,
 				       GFP_KERNEL) != 0) {
@@ -398,31 +466,39 @@ static int afs_readpage(struct file *file, struct page *page)
 	return ret;
 }
 
+#if 0
 /*
- * Make pages available as they're filled.
+ * Allow writing to a page to take place.  This function may not sleep.
  */
-static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)
+static void afs_clear_page_fscache_mark(const struct iov_iter *iter,
+					struct page *page)
 {
-#ifdef CONFIG_AFS_FSCACHE
-	struct afs_vnode *vnode = call->reply[0];
-#endif
-	struct page *page = req->pages[req->index];
+	ClearPageFsCache(page);
+}
 
-	req->pages[req->index] = NULL;
-	SetPageUptodate(page);
+static void afs_fscache_write_done(struct fscache_cookie *cookie,
+				   struct iov_iter *iter)
+{
+	struct afs_read *req = container_of(iter, struct afs_read, iter);
+
+	afs_put_read(req);
+}
+
+/*
+ * Write the read data to the cache.
+ */
+static void afs_readpages_write_to_cache(struct afs_read *req)
+{
+	struct afs_vnode *vnode = AFS_FS_I(req->iter.mapping->host);
 
-	/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
-	if (PageFsCache(page) &&
-	    fscache_write_page(vnode->cache, page, vnode->status.size,
-			       GFP_KERNEL) != 0) {
-		fscache_uncache_page(vnode->cache, page);
-		BUG_ON(PageFsCache(page));
+	if (afs_vnode_cache(vnode)) {
+		req->iter.page_done = afs_clear_page_fscache_mark;
+		fscache_write(vnode->cache, &req->iter, req->pos,
+			      req->file_size, GFP_KERNEL,
+			      afs_fscache_write_done);
 	}
-#endif
-	unlock_page(page);
-	put_page(page);
 }
+#endif
 
 /*
  * Read a contiguous set of pages.
@@ -436,7 +512,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	struct page *first, *page;
 	struct key *key = afs_file_key(file);
 	pgoff_t index;
-	int ret, n, i;
+	int ret, n;
 
 	/* Count the number of contiguous pages at the front of the list.  Note
 	 * that the list goes prev-wards rather than next-wards.
@@ -452,20 +528,17 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		n++;
 	}
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,
-		      GFP_NOFS);
+	req = kzalloc(sizeof(struct afs_read), GFP_NOFS);
 	if (!req)
 		return -ENOMEM;
 
 	refcount_set(&req->usage, 1);
-	req->page_done = afs_readpages_page_done;
+	req->cleanup = afs_file_read_cleanup;
 	req->pos = first->index;
 	req->pos <<= PAGE_SHIFT;
-	req->pages = req->array;
 
-	/* Transfer the pages to the request.  We add them in until one fails
-	 * to add to the LRU and then we stop (as that'll make a hole in the
-	 * contiguous run.
+	/* Add pages to the LRU until it fails.  We keep the pages ref'd and
+	 * locked until the read is complete.
 	 *
 	 * Note that it's possible for the file size to change whilst we're
 	 * doing this, but we rely on the server returning less than we asked
@@ -478,15 +551,11 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		index = page->index;
 		if (add_to_page_cache_lru(page, mapping, index,
 					  readahead_gfp_mask(mapping))) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
 			put_page(page);
 			break;
 		}
 
-		req->pages[req->nr_pages++] = page;
-		req->len += PAGE_SIZE;
+		req->nr_pages++;
 	} while (req->nr_pages < n);
 
 	if (req->nr_pages == 0) {
@@ -494,33 +563,26 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		return 0;
 	}
 
+	req->len = req->nr_pages * PAGE_SIZE;
+	iov_iter_mapping(&req->iter, READ, file->f_mapping, req->pos, req->len);
+	req->iter.page_done = afs_readpages_page_done;
+
 	ret = afs_fetch_data(vnode, key, req);
 	if (ret < 0)
 		goto error;
 
-	task_io_account_read(PAGE_SIZE * req->nr_pages);
-	afs_put_read(req);
+	afs_clear_after_read(vnode, req, true);
+	task_io_account_read(req->len);
 	return 0;
 
 error:
 	if (ret == -ENOENT) {
-		_debug("got NOENT from server"
-		       " - marking file deleted and stale");
+		_debug("got NOENT from server - marking file deleted and stale");
 		set_bit(AFS_VNODE_DELETED, &vnode->flags);
 		ret = -ESTALE;
 	}
 
-	for (i = 0; i < req->nr_pages; i++) {
-		page = req->pages[i];
-		if (page) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			SetPageError(page);
-			unlock_page(page);
-		}
-	}
-
+	req->error = true;
 	afs_put_read(req);
 	return ret;
 }
@@ -547,7 +609,7 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
 	}
 
 	/* attempt to read as many of the pages as possible */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	ret = fscache_read_or_alloc_pages(vnode->cache,
 					  mapping,
 					  pages,
@@ -605,7 +667,7 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
 
 	/* we clean up only if the entire page is being invalidated */
 	if (offset == 0 && length == PAGE_SIZE) {
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 		if (PageFsCache(page)) {
 			struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
 			fscache_wait_on_page_write(vnode->cache, page);
@@ -640,7 +702,7 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 
 	/* deny if page is being written to the cache and the caller hasn't
 	 * elected to wait */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
 		_leave(" = F [cache busy]");
 		return 0;
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index d9a5815945dc..eb60c570dca2 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -20,12 +20,6 @@
 
 static const struct afs_fid afs_zero_fid;
 
-/*
- * We need somewhere to discard into in case the server helpfully returns more
- * than we asked for in FS.FetchData{,64}.
- */
-static u8 afs_discard_buffer[64];
-
 static inline void afs_use_fs_server(struct afs_call *call, struct afs_cb_interest *cbi)
 {
 	call->cbi = afs_get_cb_interest(cbi);
@@ -468,115 +462,82 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 	struct afs_vnode *vnode = call->reply[0];
 	struct afs_read *req = call->reply[2];
 	const __be32 *bp;
-	unsigned int size;
-	void *buffer;
 	int ret;
 
-	_enter("{%u,%zu/%u;%llu/%llu}",
-	       call->unmarshall, call->offset, call->count,
-	       req->remain, req->actual_len);
+	_enter("{%u,%llu/%llu}",
+	       call->unmarshall, iov_iter_count(&call->iter), req->actual_len);
 
 	switch (call->unmarshall) {
 	case 0:
 		req->actual_len = 0;
-		call->offset = 0;
 		call->unmarshall++;
 		if (call->operation_ID != FSFETCHDATA64) {
 			call->unmarshall++;
 			goto no_msw;
 		}
+		afs_extract_to_tmp(call);
 
 		/* extract the upper part of the returned data length of an
-		 * FSFETCHDATA64 op (which should always be 0 using this
-		 * client) */
+		 * FSFETCHDATA64 op.
+		 */
 	case 1:
 		_debug("extract data length (MSW)");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		req->actual_len = ntohl(call->tmp);
 		req->actual_len <<= 32;
-		call->offset = 0;
 		call->unmarshall++;
-
 	no_msw:
+		afs_extract_to_tmp(call);
+
 		/* extract the returned data length */
 	case 2:
 		_debug("extract data length");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		req->actual_len |= ntohl(call->tmp);
 		_debug("DATA length: %llu", req->actual_len);
 
-		req->remain = req->actual_len;
-		call->offset = req->pos & (PAGE_SIZE - 1);
-		req->index = 0;
 		if (req->actual_len == 0)
 			goto no_more_data;
 		call->unmarshall++;
-
-	begin_page:
-		ASSERTCMP(req->index, <, req->nr_pages);
-		if (req->remain > PAGE_SIZE - call->offset)
-			size = PAGE_SIZE - call->offset;
-		else
-			size = req->remain;
-		call->count = call->offset + size;
-		ASSERTCMP(call->count, <=, PAGE_SIZE);
-		req->remain -= size;
+		call->_iter = &req->iter;
+		iov_iter_truncate(&req->iter, req->actual_len);
 
 		/* extract the returned data */
 	case 3:
-		_debug("extract data %llu/%llu %zu/%u",
-		       req->remain, req->actual_len, call->offset, call->count);
+		_debug("extract data %llu/%llu",
+		       iov_iter_count(&call->iter), req->actual_len);
 
-		buffer = kmap(req->pages[req->index]);
-		ret = afs_extract_data(call, buffer, call->count, true);
-		kunmap(req->pages[req->index]);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
-		if (call->offset == PAGE_SIZE) {
-			if (req->page_done)
-				req->page_done(call, req);
-			req->index++;
-			if (req->remain > 0) {
-				call->offset = 0;
-				if (req->index >= req->nr_pages) {
-					call->unmarshall = 4;
-					goto begin_discard;
-				}
-				goto begin_page;
-			}
-		}
-		goto no_more_data;
+
+		call->_iter = &call->iter;
+		if (req->actual_len <= req->len)
+			goto no_more_data;
 
 		/* Discard any excess data the server gave us */
-	begin_discard:
+		iov_iter_discard(&call->iter, READ, req->actual_len - req->len);
 	case 4:
-		size = min_t(loff_t, sizeof(afs_discard_buffer), req->remain);
-		call->count = size;
-		_debug("extract discard %llu/%llu %zu/%u",
-		       req->remain, req->actual_len, call->offset, call->count);
-
-		call->offset = 0;
-		ret = afs_extract_data(call, afs_discard_buffer, call->count, true);
-		req->remain -= call->offset;
+		_debug("extract discard %llu/%llu",
+		       iov_iter_count(&call->iter), req->actual_len - req->len);
+
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
-		if (req->remain > 0)
-			goto begin_discard;
 
 	no_more_data:
-		call->offset = 0;
 		call->unmarshall = 5;
+		afs_extract_to_buf(call, (21 + 3 + 6) * 4);
 
 		/* extract the metadata */
 	case 5:
-		ret = afs_extract_data(call, call->buffer,
-				       (21 + 3 + 6) * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -589,22 +550,12 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		if (call->reply[1])
 			xdr_decode_AFSVolSync(&bp, call->reply[1]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 6:
 		break;
 	}
 
-	for (; req->index < req->nr_pages; req->index++) {
-		if (call->count < PAGE_SIZE)
-			zero_user_segment(req->pages[req->index],
-					  call->count, PAGE_SIZE);
-		if (req->page_done)
-			req->page_done(call, req);
-		call->count = 0;
-	}
-
 	_leave(" = 0 [done]");
 	return 0;
 }
@@ -700,6 +651,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
 	call->expected_version = vnode->status.data_version;
+	req->call_debug_id = call->debug_id;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -1598,31 +1550,31 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 {
 	const __be32 *bp;
 	char *p;
+	u32 size;
 	int ret;
 
 	_enter("{%u}", call->unmarshall);
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->unmarshall++;
+		afs_extract_to_buf(call, 12 * 4);
 
 		/* extract the returned status record */
 	case 1:
 		_debug("extract status");
-		ret = afs_extract_data(call, call->buffer,
-				       12 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		bp = call->buffer;
 		xdr_decode_AFSFetchVolumeStatus(&bp, call->reply[1]);
-		call->offset = 0;
 		call->unmarshall++;
+		afs_extract_to_tmp(call);
 
 		/* extract the volume name length */
 	case 2:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1631,46 +1583,26 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_volname_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the volume name */
 	case 3:
 		_debug("extract volname");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("volname '%s'", p);
-
-		call->offset = 0;
-		call->unmarshall++;
-
-		/* extract the volume name padding */
-		if ((call->count & 3) == 0) {
-			call->unmarshall++;
-			goto no_volname_padding;
-		}
-		call->count = 4 - (call->count & 3);
-
-	case 4:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, true);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
-	no_volname_padding:
 
 		/* extract the offline message length */
-	case 5:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+	case 4:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1679,46 +1611,27 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_offline_msg_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the offline message */
-	case 6:
+	case 5:
 		_debug("extract offline");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("offline '%s'", p);
 
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the offline message padding */
-		if ((call->count & 3) == 0) {
-			call->unmarshall++;
-			goto no_offline_padding;
-		}
-		call->count = 4 - (call->count & 3);
-
-	case 7:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, true);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
-		call->unmarshall++;
-	no_offline_padding:
-
 		/* extract the message of the day length */
-	case 8:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+	case 6:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1727,38 +1640,24 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_motd_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the message of the day */
-	case 9:
+	case 7:
 		_debug("extract motd");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, false);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("motd '%s'", p);
 
-		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the message of the day padding */
-		call->count = (4 - (call->count & 3)) & 3;
-
-	case 10:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, false);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
-		call->unmarshall++;
-	case 11:
+	case 8:
 		break;
 	}
 
@@ -2024,19 +1923,16 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 	u32 count;
 	int ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%llu}", call->unmarshall, iov_iter_count(&call->iter));
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the capabilities word count */
 	case 1:
-		ret = afs_extract_data(call, &call->tmp,
-				       1 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2044,24 +1940,17 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 
 		call->count = count;
 		call->count2 = count;
-		call->offset = 0;
+		iov_iter_discard(&call->iter, READ, count * sizeof(__be32));
 		call->unmarshall++;
 
 		/* Extract capabilities words */
 	case 2:
-		count = min(call->count, 16U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 16);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
 		/* TODO: Examine capabilities */
 
-		call->count -= count;
-		if (call->count > 0)
-			goto again;
-		call->offset = 0;
 		call->unmarshall++;
 		break;
 	}
@@ -2215,13 +2104,13 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the file status count and array in two steps */
 	case 1:
 		_debug("extract status count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2234,11 +2123,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->count = 0;
 		call->unmarshall++;
 	more_counts:
-		call->offset = 0;
+		afs_extract_to_buf(call, 21 * sizeof(__be32));
 
 	case 2:
 		_debug("extract status array %u", call->count);
-		ret = afs_extract_data(call, call->buffer, 21 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2256,12 +2145,12 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 		call->count = 0;
 		call->unmarshall++;
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 
 		/* Extract the callback count and array in two steps */
 	case 3:
 		_debug("extract CB count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2273,11 +2162,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->count = 0;
 		call->unmarshall++;
 	more_cbs:
-		call->offset = 0;
+		afs_extract_to_buf(call, 3 * sizeof(__be32));
 
 	case 4:
 		_debug("extract CB array");
-		ret = afs_extract_data(call, call->buffer, 3 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2294,11 +2183,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		if (call->count < call->count2)
 			goto more_cbs;
 
-		call->offset = 0;
+		afs_extract_to_buf(call, 6 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 5:
-		ret = afs_extract_data(call, call->buffer, 6 * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -2306,7 +2195,6 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		if (call->reply[3])
 			xdr_decode_AFSVolSync(&bp, call->reply[3]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 6:
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 852f68a400b8..8e248051afde 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -94,11 +94,16 @@ struct afs_call {
 	struct afs_cb_interest	*cbi;		/* Callback interest for server used */
 	void			*request;	/* request data (first part) */
 	struct address_space	*mapping;	/* Pages being written from */
+	struct iov_iter		iter;		/* Buffer iterator */
+	struct iov_iter		*_iter;		/* Iterator currently in use */
+	union {	/* Convenience for ->iter */
+		struct kvec	kvec[1];
+		struct bio_vec	bvec[1];
+	};
 	void			*buffer;	/* reply receive buffer */
 	void			*reply[4];	/* Where to put the reply */
 	pgoff_t			first;		/* first page in mapping to deal with */
 	pgoff_t			last;		/* last page in mapping to deal with */
-	size_t			offset;		/* offset into received data store */
 	atomic_t		usage;
 	enum afs_call_state	state;
 	spinlock_t		state_lock;
@@ -175,15 +180,15 @@ struct afs_read {
 	loff_t			pos;		/* Where to start reading */
 	loff_t			len;		/* How much we're asking for */
 	loff_t			actual_len;	/* How much we're actually getting */
-	loff_t			remain;		/* Amount remaining */
 	loff_t			file_size;	/* File size returned by server */
 	afs_dataversion_t	data_version;	/* Version number returned by server */
 	refcount_t		usage;
-	unsigned int		index;		/* Which page we're reading into */
 	unsigned int		nr_pages;
-	void (*page_done)(struct afs_call *, struct afs_read *);
-	struct page		**pages;
-	struct page		*array[];
+	unsigned int		done_pages;
+	bool			error;
+	unsigned int		call_debug_id;
+	void (*cleanup)(struct afs_read *);
+	struct iov_iter		iter;		/* Buffer */
 };
 
 /*
@@ -547,6 +552,15 @@ struct afs_vnode {
 	afs_callback_type_t	cb_type;	/* type of callback */
 };
 
+static inline struct fscache_cookie *afs_vnode_cache(struct afs_vnode *vnode)
+{
+#ifdef CONFIG_AFS_FSCACHE
+	return vnode->cache;
+#else
+	return NULL;
+#endif
+}
+
 /*
  * cached security record for one user's attempt to access a vnode
  */
@@ -927,12 +941,34 @@ extern struct afs_call *afs_alloc_flat_call(struct afs_net *,
 extern void afs_flat_call_destructor(struct afs_call *);
 extern void afs_send_empty_reply(struct afs_call *);
 extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
-extern int afs_extract_data(struct afs_call *, void *, size_t, bool);
+extern int afs_extract_data(struct afs_call *, bool);
 extern int afs_protocol_error(struct afs_call *, int, enum afs_eproto_cause);
 
+static inline void afs_extract_begin(struct afs_call *call, void *buf, size_t size)
+{
+	call->kvec[0].iov_base = buf;
+	call->kvec[0].iov_len = size;
+	iov_iter_kvec(&call->iter, READ, call->kvec, 1, size);
+}
+
+static inline void afs_extract_to_tmp(struct afs_call *call)
+{
+	afs_extract_begin(call, &call->tmp, sizeof(call->tmp));
+}
+
+static inline void afs_extract_discard(struct afs_call *call, size_t size)
+{
+	iov_iter_discard(&call->iter, READ, size);
+}
+
+static inline void afs_extract_to_buf(struct afs_call *call, size_t size)
+{
+	afs_extract_begin(call, call->buffer, size);
+}
+
 static inline int afs_transfer_reply(struct afs_call *call)
 {
-	return afs_extract_data(call, call->buffer, call->reply_max, false);
+	return afs_extract_data(call, false);
 }
 
 static inline bool afs_check_call_state(struct afs_call *call,
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 37811901a5c9..09479677f11f 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -143,6 +143,7 @@ static struct afs_call *afs_alloc_call(struct afs_net *net,
 	INIT_WORK(&call->async_work, afs_process_async_call);
 	init_waitqueue_head(&call->waitq);
 	spin_lock_init(&call->state_lock);
+	call->_iter = &call->iter;
 
 	o = atomic_inc_return(&net->nr_outstanding_calls);
 	trace_afs_call(call, afs_call_trace_alloc, 1, o,
@@ -233,6 +234,7 @@ struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 			goto nomem_free;
 	}
 
+	afs_extract_to_buf(call, call->reply_max);
 	call->operation_ID = type->op;
 	init_waitqueue_head(&call->waitq);
 	return call;
@@ -465,14 +467,12 @@ static void afs_deliver_to_call(struct afs_call *call)
 	       state == AFS_CALL_SV_AWAIT_ACK
 	       ) {
 		if (state == AFS_CALL_SV_AWAIT_ACK) {
-			struct iov_iter iter;
-
-			iov_iter_kvec(&iter, READ, NULL, 0, 0);
+			iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
 			ret = rxrpc_kernel_recv_data(call->net->socket,
-						     call->rxcall, &iter, false,
-						     &remote_abort,
+						     call->rxcall, &call->iter,
+						     false, &remote_abort,
 						     &call->service_id);
-			trace_afs_recv_data(call, 0, 0, false, ret);
+			trace_afs_receive_data(call, &call->iter, false, ret);
 
 			if (ret == -EINPROGRESS || ret == -EAGAIN)
 				return;
@@ -516,7 +516,7 @@ static void afs_deliver_to_call(struct afs_call *call)
 			if (state != AFS_CALL_CL_AWAIT_REPLY)
 				abort_code = RXGEN_SS_UNMARSHAL;
 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
-						abort_code, -EBADMSG, "KUM");
+						abort_code, ret, "KUM");
 			goto local_abort;
 		}
 	}
@@ -729,6 +729,7 @@ void afs_charge_preallocation(struct work_struct *work)
 			call->async = true;
 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
 			init_waitqueue_head(&call->waitq);
+			afs_extract_to_tmp(call);
 		}
 
 		if (rxrpc_kernel_charge_accept(net->socket,
@@ -774,18 +775,15 @@ static int afs_deliver_cm_op_id(struct afs_call *call)
 {
 	int ret;
 
-	_enter("{%zu}", call->offset);
-
-	ASSERTCMP(call->offset, <, 4);
+	_enter("{%llu}", iov_iter_count(call->_iter));
 
 	/* the operation ID forms the first four bytes of the request data */
-	ret = afs_extract_data(call, &call->tmp, 4, true);
+	ret = afs_extract_data(call, true);
 	if (ret < 0)
 		return ret;
 
 	call->operation_ID = ntohl(call->tmp);
 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
-	call->offset = 0;
 
 	/* ask the cache manager to route the call (it'll change the call type
 	 * if successful) */
@@ -889,30 +887,19 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 /*
  * Extract a piece of data from the received data socket buffers.
  */
-int afs_extract_data(struct afs_call *call, void *buf, size_t count,
-		     bool want_more)
+int afs_extract_data(struct afs_call *call, bool want_more)
 {
 	struct afs_net *net = call->net;
-	struct iov_iter iter;
-	struct kvec iov;
+	struct iov_iter *iter = call->_iter;
 	enum afs_call_state state;
 	u32 remote_abort = 0;
 	int ret;
 
-	_enter("{%s,%zu},,%zu,%d",
-	       call->type->name, call->offset, count, want_more);
-
-	ASSERTCMP(call->offset, <=, count);
-
-	iov.iov_base = buf + call->offset;
-	iov.iov_len = count - call->offset;
-	iov_iter_kvec(&iter, READ, &iov, 1, count - call->offset);
+	_enter("{%s,%llu},%d", call->type->name, iov_iter_count(iter), want_more);
 
-	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, &iter,
+	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 				     want_more, &remote_abort,
 				     &call->service_id);
-	call->offset += (count - call->offset) - iov_iter_count(&iter);
-	trace_afs_recv_data(call, count, call->offset, want_more, ret);
 	if (ret == 0 || ret == -EAGAIN)
 		return ret;
 
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index d0f95c4ab05e..37656ba14d54 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -187,19 +187,18 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 	u32 uniquifier, nentries, count;
 	int i, ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%llu/%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_buf(call,
+				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
 		call->unmarshall++;
 
 		/* Extract the returned uuid, uniquifier, nentries and blkaddrs size */
 	case 1:
-		ret = afs_extract_data(call, call->buffer,
-				       sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -216,28 +215,28 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->reply[0] = alist;
 		call->count = count;
 		call->count2 = nentries;
-		call->offset = 0;
 		call->unmarshall++;
 
+	more_entries:
+		count = min(call->count, 4U);
+		afs_extract_to_buf(call, count * sizeof(__be32));
+
 		/* Extract entries */
 	case 2:
-		count = min(call->count, 4U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 4);
+		ret = afs_extract_data(call, call->count > 4);
 		if (ret < 0)
 			return ret;
 
 		alist = call->reply[0];
 		bp = call->buffer;
+		count = min(call->count, 4U);
 		for (i = 0; i < count; i++)
 			if (alist->nr_addrs < call->count2)
 				afs_merge_fs_addr4(alist, *bp++, AFS_FS_PORT);
 
 		call->count -= count;
 		if (call->count > 0)
-			goto again;
-		call->offset = 0;
+			goto more_entries;
 		call->unmarshall++;
 		break;
 	}
@@ -318,44 +317,35 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 	u32 count;
 	int ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%llu/%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the capabilities word count */
 	case 1:
-		ret = afs_extract_data(call, &call->tmp,
-				       1 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		count = ntohl(call->tmp);
-
 		call->count = count;
 		call->count2 = count;
-		call->offset = 0;
+
 		call->unmarshall++;
+		afs_extract_discard(call, count * sizeof(__be32));
 
 		/* Extract capabilities words */
 	case 2:
-		count = min(call->count, 16U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 16);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
 		/* TODO: Examine capabilities */
 
-		call->count -= count;
-		if (call->count > 0)
-			goto again;
-		call->offset = 0;
 		call->unmarshall++;
 		break;
 	}
@@ -426,22 +416,19 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 	u32 uniquifier, size;
 	int ret;
 
-	_enter("{%u,%zu/%u,%u}", call->unmarshall, call->offset, call->count, call->count2);
+	_enter("{%u,%llu,%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count2);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32));
 		call->unmarshall = 1;
 
 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
 		 * either the first fsEndpoint type or the volEndpoints
 		 * count if there are no fsEndpoints. */
 	case 1:
-		ret = afs_extract_data(call, call->buffer,
-				       sizeof(uuid_t) +
-				       3 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -459,15 +446,11 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			return -ENOMEM;
 		alist->version = uniquifier;
 		call->reply[0] = alist;
-		call->offset = 0;
 
 		if (call->count == 0)
 			goto extract_volendpoints;
 
-		call->unmarshall = 2;
-
-		/* Extract fsEndpoints[] entries */
-	case 2:
+	next_fsendpoint:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			size = sizeof(__be32) * (1 + 1 + 1);
@@ -481,7 +464,12 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		}
 
 		size += sizeof(__be32);
-		ret = afs_extract_data(call, call->buffer, size, true);
+		afs_extract_to_buf(call, size);
+		call->unmarshall = 2;
+
+		/* Extract fsEndpoints[] entries */
+	case 2:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -512,10 +500,9 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 */
 		call->count2 = ntohl(*bp++);
 
-		call->offset = 0;
 		call->count--;
 		if (call->count > 0)
-			goto again;
+			goto next_fsendpoint;
 
 	extract_volendpoints:
 		/* Extract the list of volEndpoints. */
@@ -526,6 +513,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_yvl_vlendpt_type);
 
+		afs_extract_to_buf(call, 1 * sizeof(__be32));
 		call->unmarshall = 3;
 
 		/* Extract the type of volEndpoints[0].  Normally we would
@@ -533,17 +521,14 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 * data of the current one, but this is the first...
 		 */
 	case 3:
-		ret = afs_extract_data(call, call->buffer, sizeof(__be32), true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		bp = call->buffer;
-		call->count2 = ntohl(*bp++);
-		call->offset = 0;
-		call->unmarshall = 4;
 
-		/* Extract volEndpoints[] entries */
-	case 4:
+	next_volendpoint:
+		call->count2 = ntohl(*bp++);
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			size = sizeof(__be32) * (1 + 1 + 1);
@@ -557,8 +542,13 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		}
 
 		if (call->count > 1)
-			size += sizeof(__be32);
-		ret = afs_extract_data(call, call->buffer, size, true);
+			size += sizeof(__be32); /* Get next type too */
+		afs_extract_to_buf(call, size);
+		call->unmarshall = 4;
+
+		/* Extract volEndpoints[] entries */
+	case 4:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -584,19 +574,17 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		/* Got either the type of the next entry or the count of
 		 * volEndpoints if no more fsEndpoints.
 		 */
-		call->offset = 0;
 		call->count--;
-		if (call->count > 0) {
-			call->count2 = ntohl(*bp++);
-			goto again;
-		}
+		if (call->count > 0)
+			goto next_volendpoint;
 
 	end:
+		afs_extract_discard(call, 0);
 		call->unmarshall = 5;
 
 		/* Done */
 	case 5:
-		ret = afs_extract_data(call, call->buffer, 0, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 		call->unmarshall = 6;
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 8b39e6ebb40b..ad3d706aa9e3 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -37,8 +37,7 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 
 	_enter(",,%llu", (unsigned long long)pos);
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-		      GFP_KERNEL);
+	req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;
 
@@ -46,9 +45,8 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 	req->pos = pos;
 	req->len = len;
 	req->nr_pages = 1;
-	req->pages = req->array;
-	req->pages[0] = page;
-	get_page(page);
+	iov_iter_mapping(&req->iter, READ, vnode->vfs_inode.i_mapping,
+			 pos, len);
 
 	ret = afs_fetch_data(vnode, key, req);
 	afs_put_read(req);
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 84b90a79d75a..d99294c75e9a 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -218,6 +218,9 @@ extern int __fscache_read_or_alloc_pages(struct fscache_cookie *,
 					 gfp_t);
 extern int __fscache_alloc_page(struct fscache_cookie *, struct page *, gfp_t);
 extern int __fscache_write_page(struct fscache_cookie *, struct page *, loff_t, gfp_t);
+extern int __fscache_write(struct fscache_cookie *, struct iov_iter *,
+			   loff_t, loff_t, gfp_t,
+			   void (*)(struct fscache_cookie *, struct iov_iter *));
 extern void __fscache_uncache_page(struct fscache_cookie *, struct page *);
 extern bool __fscache_check_page_write(struct fscache_cookie *, struct page *);
 extern void __fscache_wait_on_page_write(struct fscache_cookie *, struct page *);
@@ -655,6 +658,34 @@ void fscache_readpages_cancel(struct fscache_cookie *cookie,
 		__fscache_readpages_cancel(cookie, pages);
 }
 
+/**
+ * fscache_write - Request storage of data in the cache
+ * @cookie: The cookie representing the cache object
+ * @iter: The data to store
+ * @pos: The position in the cached data
+ * @object_size: Updated size of object
+ * @gfp: The conditions under which memory allocation should be made
+ * @done: Called upon operation completion
+ *
+ * Request the data described by the iterator be written into the cache.  This
+ * request may be ignored if insufficient space exists in the cache, in which
+ * case -ENOBUFS will be returned.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_write(struct fscache_cookie *cookie, struct iov_iter *iter,
+		  loff_t pos, loff_t object_size, gfp_t gfp,
+		  void (*done)(struct fscache_cookie *cookie,
+			       struct iov_iter *iter))
+{
+	if (fscache_cookie_valid(cookie))
+		return __fscache_write(cookie, iter, pos, object_size, gfp, done);
+	else
+		return -ENOBUFS;
+}
+
 /**
  * fscache_write_page - Request storage of a page in the cache
  * @cookie: The cookie representing the cache object
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 5c60ade2c7d8..5e0f8dcede26 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -207,17 +207,16 @@ afs_edit_dir_reasons;
 #define EM(a, b)	{ a, b },
 #define E_(a, b)	{ a, b }
 
-TRACE_EVENT(afs_recv_data,
-	    TP_PROTO(struct afs_call *call, unsigned count, unsigned offset,
+TRACE_EVENT(afs_receive_data,
+	    TP_PROTO(struct afs_call *call, struct iov_iter *iter,
 		     bool want_more, int ret),
 
-	    TP_ARGS(call, count, offset, want_more, ret),
+	    TP_ARGS(call, iter, want_more, ret),
 
 	    TP_STRUCT__entry(
+		    __field(loff_t,			remain		)
 		    __field(unsigned int,		call		)
 		    __field(enum afs_call_state,	state		)
-		    __field(unsigned int,		count		)
-		    __field(unsigned int,		offset		)
 		    __field(unsigned short,		unmarshall	)
 		    __field(bool,			want_more	)
 		    __field(int,			ret		)
@@ -227,17 +226,18 @@ TRACE_EVENT(afs_recv_data,
 		    __entry->call	= call->debug_id;
 		    __entry->state	= call->state;
 		    __entry->unmarshall	= call->unmarshall;
-		    __entry->count	= count;
-		    __entry->offset	= offset;
+		    __entry->remain	= iov_iter_count(iter);
 		    __entry->want_more	= want_more;
 		    __entry->ret	= ret;
 			   ),
 
-	    TP_printk("c=%08x s=%u u=%u %u/%u wm=%u ret=%d",
+	    TP_printk("c=%08x r=%llu u=%u w=%u s=%u ret=%d",
 		      __entry->call,
-		      __entry->state, __entry->unmarshall,
-		      __entry->offset, __entry->count,
-		      __entry->want_more, __entry->ret)
+		      __entry->remain,
+		      __entry->unmarshall,
+		      __entry->want_more,
+		      __entry->state,
+		      __entry->ret)
 	    );
 
 TRACE_EVENT(afs_notify_call,

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 07/10] afs: Use ITER_MAPPING for writing
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (5 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data() David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 08/10] afs: Add O_DIRECT read support David Howells
                   ` (2 subsequent siblings)
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Use a single ITER_MAPPING iterator to describe the portion of a file to be
transmitted to the server rather than generating a series of small
ITER_BVEC iterators on the fly.  This will make it easier to implement AIO
in afs.

In theory we could maybe use one giant ITER_BVEC, but that means
potentially allocating a huge array of bio_vec structs (max 256 per page)
when in fact the pagecache already has a structure listing all the relevant
pages (radix_tree/xarray) that can be walked over.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/file.c              |    4 --
 fs/afs/fsclient.c          |   40 +++++-------------
 fs/afs/internal.h          |   15 ++-----
 fs/afs/rxrpc.c             |   99 +++++++-------------------------------------
 fs/afs/write.c             |   84 +++++++++++++++++++++----------------
 include/trace/events/afs.h |   51 ++++++++---------------
 6 files changed, 100 insertions(+), 193 deletions(-)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 6d55dabccd79..7d65efe69929 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -195,11 +195,9 @@ static void afs_readpages_page_done(const struct iov_iter *iter,
 	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
 	struct afs_read *req = container_of(iter, struct afs_read, iter);
 
-	SetPageUptodate(page);
-
 	if (0 && afs_vnode_cache(vnode))
 		SetPageFsCache(page);
-	unlock_page(page);
+	page_endio(page, false, 0);
 	put_page(page);
 	req->done_pages++;
 }
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index eb60c570dca2..4c6997d91552 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -1230,10 +1230,7 @@ static const struct afs_call_type afs_RXFSStoreData64 = {
 /*
  * store a set of pages to a very large file
  */
-static int afs_fs_store_data64(struct afs_fs_cursor *fc,
-			       struct address_space *mapping,
-			       pgoff_t first, pgoff_t last,
-			       unsigned offset, unsigned to,
+static int afs_fs_store_data64(struct afs_fs_cursor *fc, struct iov_iter *iter,
 			       loff_t size, loff_t pos, loff_t i_size)
 {
 	struct afs_vnode *vnode = fc->vnode;
@@ -1251,13 +1248,10 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
 		return -ENOMEM;
 
 	call->key = fc->key;
-	call->mapping = mapping;
+	call->write_iter = iter;
+	call->write_first = pos >> PAGE_SHIFT;
+	call->write_last = (pos + size - 1) >> PAGE_SHIFT;
 	call->reply[0] = vnode;
-	call->first = first;
-	call->last = last;
-	call->first_offset = offset;
-	call->last_to = to;
-	call->send_pages = true;
 	call->expected_version = vnode->status.data_version + 1;
 
 	/* marshall the parameters */
@@ -1286,26 +1280,20 @@ static int afs_fs_store_data64(struct afs_fs_cursor *fc,
 }
 
 /*
- * store a set of pages
+ * Write data to a file on the server.
  */
-int afs_fs_store_data(struct afs_fs_cursor *fc, struct address_space *mapping,
-		      pgoff_t first, pgoff_t last,
-		      unsigned offset, unsigned to)
+int afs_fs_store_data(struct afs_fs_cursor *fc, struct iov_iter *iter, loff_t pos)
 {
 	struct afs_vnode *vnode = fc->vnode;
 	struct afs_call *call;
 	struct afs_net *net = afs_v2net(vnode);
-	loff_t size, pos, i_size;
+	loff_t size, i_size;
 	__be32 *bp;
 
 	_enter(",%x,{%x:%u},,",
 	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
 
-	size = (loff_t)to - (loff_t)offset;
-	if (first != last)
-		size += (loff_t)(last - first) << PAGE_SHIFT;
-	pos = (loff_t)first << PAGE_SHIFT;
-	pos += offset;
+	size = iov_iter_count(iter);
 
 	i_size = i_size_read(&vnode->vfs_inode);
 	if (pos + size > i_size)
@@ -1316,8 +1304,7 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct address_space *mapping,
 	       (unsigned long long) i_size);
 
 	if (pos >> 32 || i_size >> 32 || size >> 32 || (pos + size) >> 32)
-		return afs_fs_store_data64(fc, mapping, first, last, offset, to,
-					   size, pos, i_size);
+		return afs_fs_store_data64(fc, iter, size, pos, i_size);
 
 	call = afs_alloc_flat_call(net, &afs_RXFSStoreData,
 				   (4 + 6 + 3) * 4,
@@ -1326,13 +1313,10 @@ int afs_fs_store_data(struct afs_fs_cursor *fc, struct address_space *mapping,
 		return -ENOMEM;
 
 	call->key = fc->key;
-	call->mapping = mapping;
+	call->write_iter = iter;
+	call->write_first = pos >> PAGE_SHIFT;
+	call->write_last = (pos + size - 1) >> PAGE_SHIFT;
 	call->reply[0] = vnode;
-	call->first = first;
-	call->last = last;
-	call->first_offset = offset;
-	call->last_to = to;
-	call->send_pages = true;
 	call->expected_version = vnode->status.data_version + 1;
 
 	/* marshall the parameters */
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 8e248051afde..b12566b640f6 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -96,14 +96,15 @@ struct afs_call {
 	struct address_space	*mapping;	/* Pages being written from */
 	struct iov_iter		iter;		/* Buffer iterator */
 	struct iov_iter		*_iter;		/* Iterator currently in use */
+	struct iov_iter		*write_iter;	/* Iterator defining write to be made */
 	union {	/* Convenience for ->iter */
 		struct kvec	kvec[1];
 		struct bio_vec	bvec[1];
 	};
 	void			*buffer;	/* reply receive buffer */
 	void			*reply[4];	/* Where to put the reply */
-	pgoff_t			first;		/* first page in mapping to deal with */
-	pgoff_t			last;		/* last page in mapping to deal with */
+	pgoff_t			write_first;	/* First page of write */
+	pgoff_t			write_last;	/* Last page of write */
 	atomic_t		usage;
 	enum afs_call_state	state;
 	spinlock_t		state_lock;
@@ -111,15 +112,10 @@ struct afs_call {
 	u32			abort_code;	/* Remote abort ID or 0 */
 	unsigned		request_size;	/* size of request data */
 	unsigned		reply_max;	/* maximum size of reply */
-	unsigned		first_offset;	/* offset into mapping[first] */
 	unsigned int		cb_break;	/* cb_break + cb_s_break before the call */
-	union {
-		unsigned	last_to;	/* amount of mapping[last] */
-		unsigned	count2;		/* count used in unmarshalling */
-	};
+	unsigned		count2;		/* count used in unmarshalling */
 	unsigned char		unmarshall;	/* unmarshalling phase */
 	bool			incoming;	/* T if incoming call */
-	bool			send_pages;	/* T if data from mapping should be sent */
 	bool			need_attention;	/* T if RxRPC poked us */
 	bool			async;		/* T if asynchronous */
 	bool			ret_reply0;	/* T if should return reply[0] on success */
@@ -798,8 +794,7 @@ extern int afs_fs_symlink(struct afs_fs_cursor *, const char *, const char *, u6
 			  struct afs_fid *, struct afs_file_status *);
 extern int afs_fs_rename(struct afs_fs_cursor *, const char *,
 			 struct afs_vnode *, const char *, u64, u64);
-extern int afs_fs_store_data(struct afs_fs_cursor *, struct address_space *,
-			     pgoff_t, pgoff_t, unsigned, unsigned);
+extern int afs_fs_store_data(struct afs_fs_cursor *, struct iov_iter *, loff_t);
 extern int afs_fs_setattr(struct afs_fs_cursor *, struct iattr *);
 extern int afs_fs_get_volume_status(struct afs_fs_cursor *, struct afs_volume_status *);
 extern int afs_fs_set_lock(struct afs_fs_cursor *, afs_lock_type_t);
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 09479677f11f..fa22739cbf4f 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -258,39 +258,6 @@ void afs_flat_call_destructor(struct afs_call *call)
 	call->buffer = NULL;
 }
 
-#define AFS_BVEC_MAX 8
-
-/*
- * Load the given bvec with the next few pages.
- */
-static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
-			  struct bio_vec *bv, pgoff_t first, pgoff_t last,
-			  unsigned offset)
-{
-	struct page *pages[AFS_BVEC_MAX];
-	unsigned int nr, n, i, to, bytes = 0;
-
-	nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
-	n = find_get_pages_contig(call->mapping, first, nr, pages);
-	ASSERTCMP(n, ==, nr);
-
-	msg->msg_flags |= MSG_MORE;
-	for (i = 0; i < nr; i++) {
-		to = PAGE_SIZE;
-		if (first + i >= last) {
-			to = call->last_to;
-			msg->msg_flags &= ~MSG_MORE;
-		}
-		bv[i].bv_page = pages[i];
-		bv[i].bv_len = to - offset;
-		bv[i].bv_offset = offset;
-		bytes += to - offset;
-		offset = 0;
-	}
-
-	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
-}
-
 /*
  * Advance the AFS call state when the RxRPC call ends the transmit phase.
  */
@@ -303,41 +270,6 @@ static void afs_notify_end_request_tx(struct sock *sock,
 	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 }
 
-/*
- * attach the data from a bunch of pages on an inode to a call
- */
-static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
-{
-	struct bio_vec bv[AFS_BVEC_MAX];
-	unsigned int bytes, nr, loop, offset;
-	pgoff_t first = call->first, last = call->last;
-	int ret;
-
-	offset = call->first_offset;
-	call->first_offset = 0;
-
-	do {
-		afs_load_bvec(call, msg, bv, first, last, offset);
-		trace_afs_send_pages(call, msg, first, last, offset);
-
-		offset = 0;
-		bytes = msg->msg_iter.count;
-		nr = msg->msg_iter.nr_segs;
-
-		ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
-					     bytes, afs_notify_end_request_tx);
-		for (loop = 0; loop < nr; loop++)
-			put_page(bv[loop].bv_page);
-		if (ret < 0)
-			break;
-
-		first += nr;
-	} while (first <= last);
-
-	trace_afs_sent_pages(call, call->first, last, first, ret);
-	return ret;
-}
-
 /*
  * initiate a call
  */
@@ -367,19 +299,8 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 	 * after the initial fixed part.
 	 */
 	tx_total_len = call->request_size;
-	if (call->send_pages) {
-		if (call->last == call->first) {
-			tx_total_len += call->last_to - call->first_offset;
-		} else {
-			/* It looks mathematically like you should be able to
-			 * combine the following lines with the ones above, but
-			 * unsigned arithmetic is fun when it wraps...
-			 */
-			tx_total_len += PAGE_SIZE - call->first_offset;
-			tx_total_len += call->last_to;
-			tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
-		}
-	}
+	if (call->write_iter)
+		tx_total_len += iov_iter_count(call->write_iter);
 
 	/* create a call */
 	rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
@@ -406,7 +327,7 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 	msg.msg_control		= NULL;
 	msg.msg_controllen	= 0;
-	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
+	msg.msg_flags		= MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 
 	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 				     &msg, call->request_size,
@@ -414,8 +335,18 @@ long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 	if (ret < 0)
 		goto error_do_abort;
 
-	if (call->send_pages) {
-		ret = afs_send_pages(call, &msg);
+	if (call->write_iter) {
+		msg.msg_iter = *call->write_iter;
+		msg.msg_flags &= ~MSG_MORE;
+		trace_afs_send_data(call, &msg);
+
+		ret = rxrpc_kernel_send_data(call->net->socket,
+					     call->rxcall, &msg,
+					     iov_iter_count(&msg.msg_iter),
+					     afs_notify_end_request_tx);
+		*call->write_iter = msg.msg_iter;
+
+		trace_afs_sent_data(call, &msg, ret);
 		if (ret < 0)
 			goto error_do_abort;
 	}
diff --git a/fs/afs/write.c b/fs/afs/write.c
index ad3d706aa9e3..8ce5142f0f08 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -302,22 +302,21 @@ static void afs_redirty_pages(struct writeback_control *wbc,
 /*
  * write to a file
  */
-static int afs_store_data(struct address_space *mapping,
-			  pgoff_t first, pgoff_t last,
-			  unsigned offset, unsigned to)
+static int afs_store_data(struct afs_vnode *vnode, struct iov_iter *iter,
+			  loff_t pos)
 {
-	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
 	struct afs_fs_cursor fc;
 	struct afs_wb_key *wbk = NULL;
 	struct list_head *p;
+	loff_t count = iov_iter_count(iter);
 	int ret = -ENOKEY, ret2;
 
-	_enter("%s{%x:%u.%u},%lx,%lx,%x,%x",
+	_enter("%s{%x:%u.%u},%llx,%llx",
 	       vnode->volume->name,
 	       vnode->fid.vid,
 	       vnode->fid.vnode,
 	       vnode->fid.unique,
-	       first, last, offset, to);
+	       count, pos);
 
 	spin_lock(&vnode->wb_lock);
 	p = vnode->wb_keys.next;
@@ -350,7 +349,7 @@ static int afs_store_data(struct address_space *mapping,
 	if (afs_begin_vnode_operation(&fc, vnode, wbk->key)) {
 		while (afs_select_fileserver(&fc)) {
 			fc.cb_break = afs_calc_vnode_cb_break(vnode);
-			afs_fs_store_data(&fc, mapping, first, last, offset, to);
+			afs_fs_store_data(&fc, iter, pos);
 		}
 
 		afs_check_for_remote_deletion(&fc, fc.vnode);
@@ -361,9 +360,7 @@ static int afs_store_data(struct address_space *mapping,
 	switch (ret) {
 	case 0:
 		afs_stat_v(vnode, n_stores);
-		atomic_long_add((last * PAGE_SIZE + to) -
-				(first * PAGE_SIZE + offset),
-				&afs_v2net(vnode)->n_store_bytes);
+		atomic_long_add(count, &afs_v2net(vnode)->n_store_bytes);
 		break;
 	case -EACCES:
 	case -EPERM:
@@ -393,10 +390,12 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 					   pgoff_t final_page)
 {
 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+	struct iov_iter iter;
 	struct page *pages[8], *page;
 	unsigned long count, priv;
 	unsigned n, offset, to, f, t;
 	pgoff_t start, first, last;
+	loff_t a, b;
 	int loop, ret;
 
 	_enter(",%lx", primary_page->index);
@@ -496,10 +495,17 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 
 	first = primary_page->index;
 	last = first + count - 1;
-
 	_debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to);
 
-	ret = afs_store_data(mapping, first, last, offset, to);
+	a = first;
+	a <<= PAGE_SHIFT;
+	a += offset;
+	b = last;
+	b <<= PAGE_SHIFT;
+	b += to;
+	iov_iter_mapping(&iter, WRITE, mapping, a, b - a);
+
+	ret = afs_store_data(vnode, &iter, a);
 	switch (ret) {
 	case 0:
 		ret = count;
@@ -668,36 +674,35 @@ int afs_writepages(struct address_space *mapping,
  */
 void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
 {
-	struct pagevec pv;
+	struct radix_tree_iter iter;
+	struct address_space *mapping = vnode->vfs_inode.i_mapping;
 	unsigned long priv;
-	unsigned count, loop;
-	pgoff_t first = call->first, last = call->last;
+	pgoff_t cursor = call->write_first, last = call->write_last;
+	void __rcu **slot;
 
 	_enter("{%x:%u},{%lx-%lx}",
-	       vnode->fid.vid, vnode->fid.vnode, first, last);
+	       vnode->fid.vid, vnode->fid.vnode, cursor, last);
 
-	pagevec_init(&pv);
+	rcu_read_lock();
 
-	do {
-		_debug("done %lx-%lx", first, last);
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, cursor) {
+		struct page *page = radix_tree_deref_slot(slot);
 
-		count = last - first + 1;
-		if (count > PAGEVEC_SIZE)
-			count = PAGEVEC_SIZE;
-		pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping,
-					      first, count, pv.pages);
-		ASSERTCMP(pv.nr, ==, count);
+		ASSERT(page);
+		ASSERT(PageWriteback(page));
 
-		for (loop = 0; loop < count; loop++) {
-			priv = page_private(pv.pages[loop]);
-			trace_afs_page_dirty(vnode, tracepoint_string("clear"),
-					     pv.pages[loop]->index, priv);
-			set_page_private(pv.pages[loop], 0);
-			end_page_writeback(pv.pages[loop]);
-		}
-		first += count;
-		__pagevec_release(&pv);
-	} while (first <= last);
+		priv = page_private(page);
+		trace_afs_page_dirty(vnode, tracepoint_string("clear"),
+				     page->index, priv);
+		set_page_private(page, 0);
+		page_endio(page, true, 0);
+
+		if (cursor >= last)
+			break;
+		cursor++;
+	}
+
+	rcu_read_unlock();
 
 	afs_prune_wb_keys(vnode);
 	_leave("");
@@ -829,6 +834,8 @@ int afs_launder_page(struct page *page)
 {
 	struct address_space *mapping = page->mapping;
 	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+	struct iov_iter iter;
+	struct bio_vec bv[1];
 	unsigned long priv;
 	unsigned int f, t;
 	int ret = 0;
@@ -844,9 +851,14 @@ int afs_launder_page(struct page *page)
 			t = priv >> AFS_PRIV_SHIFT;
 		}
 
+		bv[0].bv_page = page;
+		bv[0].bv_offset = f;
+		bv[0].bv_len = t - f;
+		iov_iter_bvec(&iter, WRITE, bv, 1, bv[0].bv_len);
+
 		trace_afs_page_dirty(vnode, tracepoint_string("launder"),
 				     page->index, priv);
-		ret = afs_store_data(mapping, page->index, page->index, t, f);
+		ret = afs_store_data(vnode, &iter, (loff_t)page->index << PAGE_SHIFT);
 	}
 
 	trace_afs_page_dirty(vnode, tracepoint_string("laundered"),
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 5e0f8dcede26..9c44245987b3 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -392,65 +392,52 @@ 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.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 c=%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.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 c=%llx r=%d",
+		      __entry->call, __entry->offset, __entry->count,
+		      __entry->ret)
 	    );
 
 TRACE_EVENT(afs_dir_check_failed,

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 08/10] afs: Add O_DIRECT read support
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (6 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 07/10] afs: Use ITER_MAPPING for writing David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors David Howells
  2018-08-06 13:17 ` [PATCH 10/10] afs: Don't invoke the server to read data beyond EOF David Howells
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Add synchronous O_DIRECT read support to AFS (no AIO yet).  It can
theoretically handle reads up to the maximum size describable by loff_t -
and given an iterator with sufficiently capacity to handle that and given
support on the server.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/file.c     |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/afs/internal.h |    1 +
 fs/afs/write.c    |    8 +++++++
 3 files changed, 70 insertions(+)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 7d65efe69929..095ef4b4a0e7 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -27,6 +27,7 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags);
 
 static int afs_readpages(struct file *filp, struct address_space *mapping,
 			 struct list_head *pages, unsigned nr_pages);
+static ssize_t afs_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
 
 const struct file_operations afs_file_operations = {
 	.open		= afs_open,
@@ -55,6 +56,7 @@ const struct address_space_operations afs_fs_aops = {
 	.launder_page	= afs_launder_page,
 	.releasepage	= afs_releasepage,
 	.invalidatepage	= afs_invalidatepage,
+	.direct_IO	= afs_direct_IO,
 	.write_begin	= afs_write_begin,
 	.write_end	= afs_write_end,
 	.writepage	= afs_writepage,
@@ -732,3 +734,62 @@ static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
 		vma->vm_ops = &afs_vm_ops;
 	return ret;
 }
+
+/*
+ * Direct file read operation for an AFS file.
+ */
+static ssize_t afs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct afs_vnode *vnode = AFS_FS_I(mapping->host);
+	struct afs_read *req;
+	struct key *key = afs_file_key(file);
+	ssize_t ret;
+	size_t count = iov_iter_count(iter), transferred = 0;
+
+	if (!count)
+		return 0;
+	if (!is_sync_kiocb(iocb))
+		return -EOPNOTSUPP;
+
+	req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	refcount_set(&req->usage, 1);
+	req->pos = iocb->ki_pos;
+	req->len = count;
+	req->iter = *iter;
+
+	task_io_account_read(count);
+
+
+	// TODO afs_start_io_direct(inode);
+	ret = afs_fetch_data(vnode, key, req);
+	if (ret == 0)
+		transferred = req->actual_len;
+	*iter = req->iter;
+	afs_put_read(req);
+
+	// TODO afs_end_io_direct(inode);
+
+	BUG_ON(ret == -EIOCBQUEUED); // TODO
+
+	if (ret == 0)
+		ret = transferred;
+
+	return ret;
+}
+
+/*
+ * Do direct I/O.
+ */
+static ssize_t afs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
+
+	if (iov_iter_rw(iter) == READ)
+		return afs_file_direct_read(iocb, iter);
+	return afs_file_direct_write(iocb, iter);
+}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b12566b640f6..ac763e651c42 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1110,6 +1110,7 @@ extern int afs_fsync(struct file *, loff_t, loff_t, int);
 extern int afs_page_mkwrite(struct vm_fault *);
 extern void afs_prune_wb_keys(struct afs_vnode *);
 extern int afs_launder_page(struct page *);
+extern ssize_t afs_file_direct_write(struct kiocb *, struct iov_iter *);
 
 /*
  * xattr.c
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 8ce5142f0f08..18b836b473f2 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -874,3 +874,11 @@ int afs_launder_page(struct page *page)
 #endif
 	return ret;
 }
+
+/*
+ * Direct file write operation for an AFS file.
+ */
+ssize_t afs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
+{
+	return -EOPNOTSUPP;
+}

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (7 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 08/10] afs: Add O_DIRECT read support David Howells
@ 2018-08-06 13:17 ` David Howells
  2018-08-06 13:17 ` [PATCH 10/10] afs: Don't invoke the server to read data beyond EOF David Howells
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

Add a couple of tracepoints to log the production of I/O errors within the AFS
filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cmservice.c         |   10 +++--
 fs/afs/dir.c               |   23 ++++++++----
 fs/afs/internal.h          |   11 ++++++
 fs/afs/mntpt.c             |    2 +
 fs/afs/rxrpc.c             |    2 +
 fs/afs/server.c            |    4 +-
 fs/afs/volume.c            |    2 +
 fs/afs/write.c             |    1 +
 include/trace/events/afs.h |   81 ++++++++++++++++++++++++++++++++++++++++++++
 9 files changed, 117 insertions(+), 19 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 4db62ae8dc1a..186f621f8722 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -260,7 +260,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 	}
 
 	if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
-		return -EIO;
+		return afs_io_error(call, afs_io_error_cm_reply);
 
 	/* we'll need the file server record as that tells us which set of
 	 * vnodes to operate upon */
@@ -368,7 +368,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 	}
 
 	if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
-		return -EIO;
+		return afs_io_error(call, afs_io_error_cm_reply);
 
 	/* we'll need the file server record as that tells us which set of
 	 * vnodes to operate upon */
@@ -409,7 +409,7 @@ static int afs_deliver_cb_probe(struct afs_call *call)
 		return ret;
 
 	if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
-		return -EIO;
+		return afs_io_error(call, afs_io_error_cm_reply);
 
 	return afs_queue_call_work(call);
 }
@@ -490,7 +490,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 	}
 
 	if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
-		return -EIO;
+		return afs_io_error(call, afs_io_error_cm_reply);
 
 	return afs_queue_call_work(call);
 }
@@ -573,7 +573,7 @@ static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
 		return ret;
 
 	if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
-		return -EIO;
+		return afs_io_error(call, afs_io_error_cm_reply);
 
 	return afs_queue_call_work(call);
 }
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 1357a10804bb..300514cb33d8 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -173,6 +173,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 			       ntohs(dbuf->blocks[tmp].hdr.magic));
 			trace_afs_dir_check_failed(dvnode, off, i_size);
 			kunmap(page);
+			trace_afs_file_error(dvnode, -EIO, afs_file_error_dir_bad_magic);
 			goto error;
 		}
 
@@ -273,12 +274,15 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 
 expand:
 	i_size = i_size_read(&dvnode->vfs_inode);
-	ret = -EIO;
-	if (i_size < 2048)
+	if (i_size < 2048) {
+		ret = afs_bad(dvnode, afs_file_error_dir_small);
 		goto error;
-	ret = -EFBIG;
-	if (i_size > 2048 * 1024)
+	}
+	if (i_size > 2048 * 1024) {
+		trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big);
+		ret = -EFBIG;
 		goto error;
+	}
 
 	nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
 
@@ -383,7 +387,8 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 /*
  * deal with one block in an AFS directory
  */
-static int afs_dir_iterate_block(struct dir_context *ctx,
+static int afs_dir_iterate_block(struct afs_vnode *dvnode,
+				 struct dir_context *ctx,
 				 union afs_xdr_dir_block *block,
 				 unsigned blkoff)
 {
@@ -433,7 +438,7 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
 				       " (len %u/%zu)",
 				       blkoff / sizeof(union afs_xdr_dir_block),
 				       offset, next, tmp, nlen);
-				return -EIO;
+				return afs_bad(dvnode, afs_file_error_dir_over_end);
 			}
 			if (!(block->hdr.bitmap[next / 8] &
 			      (1 << (next % 8)))) {
@@ -441,7 +446,7 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
 				       " %u unmarked extension (len %u/%zu)",
 				       blkoff / sizeof(union afs_xdr_dir_block),
 				       offset, next, tmp, nlen);
-				return -EIO;
+				return afs_bad(dvnode, afs_file_error_dir_unmarked_ext);
 			}
 
 			_debug("ENT[%zu.%u]: ext %u/%zu",
@@ -517,7 +522,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 			page = radix_tree_deref_slot(slot);
 		rcu_read_unlock();
 		if (!page) {
-			ret = -EIO;
+			ret = afs_bad(dvnode, afs_file_error_dir_missing_page);
 			break;
 		}
 		mark_page_accessed(page);
@@ -530,7 +535,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 		do {
 			dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 					       sizeof(union afs_xdr_dir_block)];
-			ret = afs_dir_iterate_block(ctx, dblock, blkoff);
+			ret = afs_dir_iterate_block(dvnode, ctx, dblock, blkoff);
 			if (ret != 1) {
 				kunmap(page);
 				goto out;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index ac763e651c42..8e2941cafc36 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1149,6 +1149,17 @@ static inline void afs_check_for_remote_deletion(struct afs_fs_cursor *fc,
 	}
 }
 
+static inline int afs_io_error(struct afs_call *call, enum afs_io_error where)
+{
+	trace_afs_io_error(call->debug_id, -EIO, where);
+	return -EIO;
+}
+
+static inline int afs_bad(struct afs_vnode *vnode, enum afs_file_error where)
+{
+	trace_afs_file_error(vnode, -EIO, where);
+	return -EIO;
+}
 
 /*****************************************************************************/
 /*
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index c8a7f05b9f12..822d62790a74 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -122,7 +122,7 @@ static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
 
 		if (PageError(page)) {
 			put_page(page);
-			return -EIO;
+			return afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt);
 		}
 
 		buf = kmap(page);
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index fa22739cbf4f..36363c33097b 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -845,7 +845,7 @@ int afs_extract_data(struct afs_call *call, bool want_more)
 			break;
 		case AFS_CALL_COMPLETE:
 			kdebug("prem complete %d", call->error);
-			return -EIO;
+			return afs_io_error(call, afs_io_error_extract);
 		default:
 			break;
 		}
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 1d329e6981d5..b7874bf9402e 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -274,7 +274,7 @@ static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
 		case -ECONNREFUSED:
 			break;
 		default:
-			ac.error = -EIO;
+			ac.error = afs_io_error(NULL, afs_io_error_vl_lookup_fail);
 			goto error;
 		}
 	}
@@ -560,7 +560,7 @@ static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
 		case -ETIME:
 			break;
 		default:
-			fc->ac.error = -EIO;
+			fc->ac.error = afs_io_error(NULL, afs_io_error_fs_probe_fail);
 			goto error;
 		}
 	}
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 7adcddf02e66..23dde4624d06 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -116,7 +116,7 @@ static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
 		case -ECONNREFUSED:
 			break;
 		default:
-			ac.error = -EIO;
+			ac.error = afs_io_error(NULL, afs_io_error_vl_lookup_fail);
 			goto error;
 		}
 	}
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 18b836b473f2..6ff0f25836de 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -537,6 +537,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
 	case -ENOENT:
 	case -ENOMEDIUM:
 	case -ENXIO:
+		trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
 		afs_kill_pages(mapping, first, last);
 		mapping_set_error(mapping, ret);
 		break;
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 9c44245987b3..d9c99c423fd9 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -103,6 +103,24 @@ enum afs_eproto_cause {
 	afs_eproto_yvl_vlendpt_type,
 };
 
+enum afs_io_error {
+	afs_io_error_cm_reply,
+	afs_io_error_extract,
+	afs_io_error_fs_probe_fail,
+	afs_io_error_vl_lookup_fail,
+};
+
+enum afs_file_error {
+	afs_file_error_dir_bad_magic,
+	afs_file_error_dir_big,
+	afs_file_error_dir_missing_page,
+	afs_file_error_dir_over_end,
+	afs_file_error_dir_small,
+	afs_file_error_dir_unmarked_ext,
+	afs_file_error_mntpt,
+	afs_file_error_writeback_fail,
+};
+
 #endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */
 
 /*
@@ -183,6 +201,21 @@ enum afs_eproto_cause {
 	EM(afs_eproto_yvl_vlendpt6_len,	"YVL.VlEnd6Len") \
 	E_(afs_eproto_yvl_vlendpt_type,	"YVL.VlEndType")
 
+#define afs_io_errors							\
+	EM(afs_io_error_cm_reply,		"CM_REPLY")		\
+	EM(afs_io_error_extract,		"EXTRACT")		\
+	EM(afs_io_error_fs_probe_fail,		"FS_PROBE_FAIL")	\
+	E_(afs_io_error_vl_lookup_fail,		"VL_LOOKUP_FAIL")
+
+#define afs_file_errors							\
+	EM(afs_file_error_dir_bad_magic,	"DIR_BAD_MAGIC")	\
+	EM(afs_file_error_dir_big,		"DIR_BIG")		\
+	EM(afs_file_error_dir_missing_page,	"DIR_MISSING_PAGE")	\
+	EM(afs_file_error_dir_over_end,		"DIR_ENT_OVER_END")	\
+	EM(afs_file_error_dir_small,		"DIR_SMALL")		\
+	EM(afs_file_error_dir_unmarked_ext,	"DIR_UNMARKED_EXT")	\
+	EM(afs_file_error_mntpt,		"MNTPT_READ_FAILED")	\
+	E_(afs_file_error_writeback_fail,	"WRITEBACK_FAILED")
 
 /*
  * Export enum symbols via userspace.
@@ -197,6 +230,9 @@ afs_fs_operations;
 afs_vl_operations;
 afs_edit_dir_ops;
 afs_edit_dir_reasons;
+afs_eproto_causes;
+afs_io_errors;
+afs_file_errors;
 
 /*
  * Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -600,6 +636,51 @@ TRACE_EVENT(afs_protocol_error,
 		      __print_symbolic(__entry->cause, afs_eproto_causes))
 	    );
 
+TRACE_EVENT(afs_io_error,
+	    TP_PROTO(unsigned int call, int error, enum afs_io_error where),
+
+	    TP_ARGS(call, error, where),
+
+	    TP_STRUCT__entry(
+		    __field(unsigned int,	call		)
+		    __field(int,		error		)
+		    __field(enum afs_io_error,	where		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->call = call;
+		    __entry->error = error;
+		    __entry->where = where;
+			   ),
+
+	    TP_printk("c=%08x r=%d %s",
+		      __entry->call, __entry->error,
+		      __print_symbolic(__entry->where, afs_io_errors))
+	    );
+
+TRACE_EVENT(afs_file_error,
+	    TP_PROTO(struct afs_vnode *vnode, int error, enum afs_file_error where),
+
+	    TP_ARGS(vnode, error, where),
+
+	    TP_STRUCT__entry(
+		    __field_struct(struct afs_fid,	fid		)
+		    __field(int,			error		)
+		    __field(enum afs_file_error,	where		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->fid = vnode->fid;
+		    __entry->error = error;
+		    __entry->where = where;
+			   ),
+
+	    TP_printk("%x:%x:%x r=%d %s",
+		      __entry->fid.vid, __entry->fid.vnode, __entry->fid.unique,
+		      __entry->error,
+		      __print_symbolic(__entry->where, afs_file_errors))
+	    );
+
 TRACE_EVENT(afs_cm_no_server,
 	    TP_PROTO(struct afs_call *call, struct sockaddr_rxrpc *srx),
 

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 10/10] afs: Don't invoke the server to read data beyond EOF
  2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
                   ` (8 preceding siblings ...)
  2018-08-06 13:17 ` [PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors David Howells
@ 2018-08-06 13:17 ` David Howells
  9 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-08-06 13:17 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-afs, linux-fsdevel, linux-kernel, matthew

When writing a new page, clear space in the page rather than attempting to
load it from the server if the space is beyond the EOF.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/write.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 6ff0f25836de..7c7a03310f16 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -33,10 +33,21 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 			 loff_t pos, unsigned int len, struct page *page)
 {
 	struct afs_read *req;
+	size_t p;
+	void *data;
 	int ret;
 
 	_enter(",,%llu", (unsigned long long)pos);
 
+	if (pos >= vnode->vfs_inode.i_size) {
+		p = pos & ~PAGE_MASK;
+		ASSERTCMP(p + len, <=, PAGE_SIZE);
+		data = kmap(page);
+		memset(data + p, 0, len);
+		kunmap(page);
+		return 0;
+	}
+
 	req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data()
  2018-09-13 15:51 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
@ 2018-09-13 15:52 ` David Howells
  0 siblings, 0 replies; 12+ messages in thread
From: David Howells @ 2018-09-13 15:52 UTC (permalink / raw)
  To: viro; +Cc: dhowells, linux-fsdevel, linux-afs, linux-kernel

afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.

Instead:

 (1) Put an iterator in the afs_call struct.

 (2) Set the iterator for each marshalling stage to load data into the
     appropriate places.  A number of convenience functions are provided to
     this end (eg. afs_extract_to_buf()).

     This iterator is then passed to afs_extract_data().

 (3) Use the new ITER_MAPPING iterator when reading data to load directly
     into the inode's pages without needing to create a list of them.  This
     comes with a page-done callback that can be used to unlock pages as
     they are filled.

 (4) Use the new ITER_DISCARD iterator to discard any excess data provided
     by FetchData.

This will allow O_DIRECT calls to be supported in future patches.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cmservice.c         |   40 +++----
 fs/afs/dir.c               |  191 +++++++++++++++++++++++----------
 fs/afs/file.c              |  199 +++++++++++++++++++++++------------
 fs/afs/fsclient.c          |  252 ++++++++++++--------------------------------
 fs/afs/internal.h          |   52 ++++++++-
 fs/afs/rxrpc.c             |   41 ++-----
 fs/afs/vlclient.c          |  104 ++++++++----------
 fs/afs/write.c             |    8 +
 include/linux/fscache.h    |   31 +++++
 include/trace/events/afs.h |   22 ++--
 10 files changed, 499 insertions(+), 441 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 58f79301a716..4db62ae8dc1a 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -176,13 +176,13 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* extract the FID array and its count in two steps */
 	case 1:
 		_debug("extract FID count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -196,13 +196,12 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 				       GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
-		call->offset = 0;
+		afs_extract_to_buf(call, call->count * 3 * 4);
 		call->unmarshall++;
 
 	case 2:
 		_debug("extract FID array");
-		ret = afs_extract_data(call, call->buffer,
-				       call->count * 3 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -222,13 +221,13 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 			cb->cb.type	= AFSCM_CB_UNTYPED;
 		}
 
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* extract the callback array and its count in two steps */
 	case 3:
 		_debug("extract CB count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -237,13 +236,12 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		if (call->count2 != call->count && call->count2 != 0)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_cb_count);
-		call->offset = 0;
+		afs_extract_to_buf(call, call->count2 * 3 * 4);
 		call->unmarshall++;
 
 	case 4:
 		_debug("extract CB array");
-		ret = afs_extract_data(call, call->buffer,
-				       call->count2 * 3 * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -256,7 +254,6 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 			cb->cb.type	= ntohl(*bp++);
 		}
 
-		call->offset = 0;
 		call->unmarshall++;
 	case 5:
 		break;
@@ -303,7 +300,8 @@ static int afs_deliver_cb_init_call_back_state(struct afs_call *call)
 
 	rxrpc_kernel_get_peer(call->net->socket, call->rxcall, &srx);
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
@@ -332,16 +330,15 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
+		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 1:
 		_debug("extract UUID");
-		ret = afs_extract_data(call, call->buffer,
-				       11 * sizeof(__be32), false);
+		ret = afs_extract_data(call, false);
 		switch (ret) {
 		case 0:		break;
 		case -EAGAIN:	return 0;
@@ -364,7 +361,6 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 		for (loop = 0; loop < 6; loop++)
 			r->node[loop] = ntohl(b[loop + 5]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 2:
@@ -407,7 +403,8 @@ static int afs_deliver_cb_probe(struct afs_call *call)
 
 	_enter("");
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
@@ -455,16 +452,15 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
 		if (!call->buffer)
 			return -ENOMEM;
+		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 1:
 		_debug("extract UUID");
-		ret = afs_extract_data(call, call->buffer,
-				       11 * sizeof(__be32), false);
+		ret = afs_extract_data(call, false);
 		switch (ret) {
 		case 0:		break;
 		case -EAGAIN:	return 0;
@@ -487,7 +483,6 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 		for (loop = 0; loop < 6; loop++)
 			r->node[loop] = ntohl(b[loop + 5]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 2:
@@ -572,7 +567,8 @@ static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
 
 	_enter("");
 
-	ret = afs_extract_data(call, NULL, 0, false);
+	afs_extract_discard(call, 0);
+	ret = afs_extract_data(call, false);
 	if (ret < 0)
 		return ret;
 
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 855bf2b79fed..c36b54b7450b 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -105,6 +105,40 @@ struct afs_lookup_cookie {
 	struct afs_fid		fids[50];
 };
 
+/*
+ * Drop the refs that we're holding on the pages we were reading into.  We've
+ * got refs on the first nr_pages pages.
+ */
+static void afs_dir_read_cleanup(struct afs_read *req)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = req->iter.mapping;
+	struct page *page;
+	pgoff_t index = req->pos >> PAGE_SHIFT;
+	void __rcu **slot;
+
+	if (unlikely(!req->nr_pages))
+		return;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page))
+			continue;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page->mapping != req->iter.mapping);
+
+		put_page(page);
+		req->nr_pages--;
+		if (req->nr_pages == 0)
+			break;
+	}
+
+	rcu_read_unlock();
+}
+
 /*
  * check that a directory page is valid
  */
@@ -130,7 +164,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 	qty /= sizeof(union afs_xdr_dir_block);
 
 	/* check them */
-	dbuf = kmap(page);
+	dbuf = kmap_atomic(page);
 	for (tmp = 0; tmp < qty; tmp++) {
 		if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
 			printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
@@ -148,7 +182,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 		((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
 	}
 
-	kunmap(page);
+	kunmap_atomic(dbuf);
 
 checked:
 	afs_stat_v(dvnode, n_read_dir);
@@ -158,6 +192,45 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 	return false;
 }
 
+/*
+ * Check all the pages in a directory.  All the pages are held pinned.
+ */
+static int afs_dir_check(struct afs_vnode *dvnode, unsigned int nr_pages,
+			 loff_t i_size)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = dvnode->vfs_inode.i_mapping;
+	struct page *page;
+	void __rcu **slot;
+	int ret = 0;
+
+	if (unlikely(!nr_pages))
+		return 0;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, 0) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page)) {
+			pr_warn("kAFS: Missing page in dircheck\n");
+			ret = -EIO;
+			break;
+		}
+		if (page->index >= nr_pages)
+			break;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page->mapping != mapping);
+
+		ret = afs_dir_check_page(dvnode, page, i_size);
+		if (ret < 0)
+			break;
+	}
+
+	rcu_read_unlock();
+	return ret;
+}
+
 /*
  * open an AFS directory file
  */
@@ -184,56 +257,49 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 {
 	struct afs_read *req;
 	loff_t i_size;
-	int nr_pages, nr_inline, i, n;
-	int ret = -ENOMEM;
+	int nr_pages, i, n;
+	int ret;
+
+	_enter("");
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	refcount_set(&req->usage, 1);
+	req->cleanup = afs_dir_read_cleanup;
 
-retry:
+expand:
 	i_size = i_size_read(&dvnode->vfs_inode);
+	ret = -EIO;
 	if (i_size < 2048)
-		return ERR_PTR(-EIO);
+		goto error;
+	ret = -EFBIG;
 	if (i_size > 2048 * 1024)
-		return ERR_PTR(-EFBIG);
-
-	_enter("%llu", i_size);
+		goto error;
 
-	/* Get a request record to hold the page list.  We want to hold it
-	 * inline if we can, but we don't want to make an order 1 allocation.
-	 */
 	nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
-	nr_inline = nr_pages;
-	if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
-		nr_inline = 0;
 
-	req = kzalloc(sizeof(*req) + sizeof(struct page *) * nr_inline,
-		      GFP_KERNEL);
-	if (!req)
-		return ERR_PTR(-ENOMEM);
-
-	refcount_set(&req->usage, 1);
-	req->nr_pages = nr_pages;
 	req->actual_len = i_size; /* May change */
 	req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
 	req->data_version = dvnode->status.data_version; /* May change */
-	if (nr_inline > 0) {
-		req->pages = req->array;
-	} else {
-		req->pages = kcalloc(nr_pages, sizeof(struct page *),
-				     GFP_KERNEL);
-		if (!req->pages)
-			goto error;
-	}
+	iov_iter_mapping(&req->iter, READ, dvnode->vfs_inode.i_mapping,
+			 0, i_size);
 
-	/* Get a list of all the pages that hold or will hold the directory
-	 * content.  We need to fill in any gaps that we might find where the
-	 * memory reclaimer has been at work.  If there are any gaps, we will
+	/* Fill in any gaps that we might find where the memory reclaimer has
+	 * been at work and pin all the pages.  If there are any gaps, we will
 	 * need to reread the entire directory contents.
 	 */
-	i = 0;
-	do {
+	i = req->nr_pages;
+	while (i < nr_pages) {
+		struct page *pages[8], *page;
+
 		n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
-					  req->nr_pages - i,
-					  req->pages + i);
-		_debug("find %u at %u/%u", n, i, req->nr_pages);
+					  min_t(unsigned int, nr_pages - i,
+						ARRAY_SIZE(pages)),
+					  pages);
+		_debug("find %u at %u/%u", n, i, nr_pages);
+
 		if (n == 0) {
 			gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
 
@@ -241,23 +307,25 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 				afs_stat_v(dvnode, n_inval);
 
 			ret = -ENOMEM;
-			req->pages[i] = __page_cache_alloc(gfp);
-			if (!req->pages[i])
+			page = __page_cache_alloc(gfp);
+			if (!page)
 				goto error;
-			ret = add_to_page_cache_lru(req->pages[i],
+			ret = add_to_page_cache_lru(page,
 						    dvnode->vfs_inode.i_mapping,
 						    i, gfp);
 			if (ret < 0)
 				goto error;
 
-			set_page_private(req->pages[i], 1);
-			SetPagePrivate(req->pages[i]);
-			unlock_page(req->pages[i]);
+			set_page_private(page, 1);
+			SetPagePrivate(page);
+			unlock_page(page);
+			req->nr_pages++;
 			i++;
 		} else {
+			req->nr_pages += n;
 			i += n;
 		}
-	} while (i < req->nr_pages);
+	}
 
 	/* If we're going to reload, we need to lock all the pages to prevent
 	 * races.
@@ -280,15 +348,18 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 
 		task_io_account_read(PAGE_SIZE * req->nr_pages);
 
-		if (req->len < req->file_size)
-			goto content_has_grown;
+		if (req->len < req->file_size) {
+			/* The content has grown, so we need to expand the
+			 * buffer.
+			 */
+			up_write(&dvnode->validate_lock);
+			goto expand;
+		}
 
 		/* Validate the data we just read. */
-		ret = -EIO;
-		for (i = 0; i < req->nr_pages; i++)
-			if (!afs_dir_check_page(dvnode, req->pages[i],
-						req->actual_len))
-				goto error_unlock;
+		ret = afs_dir_check(dvnode, req->nr_pages, req->actual_len);
+		if (ret < 0)
+			goto error_unlock;
 
 		// TODO: Trim excess pages
 
@@ -305,11 +376,6 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 	afs_put_read(req);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
-
-content_has_grown:
-	up_write(&dvnode->validate_lock);
-	afs_put_read(req);
-	goto retry;
 }
 
 /*
@@ -415,6 +481,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 	struct afs_read *req;
 	struct page *page;
 	unsigned blkoff, limit;
+	void __rcu **slot;
 	int ret;
 
 	_enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
@@ -438,9 +505,15 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 		blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
 
 		/* Fetch the appropriate page from the directory and re-add it
-		 * to the LRU.
+		 * to the LRU.  We have all the pages pinned with an extra ref.
 		 */
-		page = req->pages[blkoff / PAGE_SIZE];
+		rcu_read_lock();
+		page = NULL;
+		slot = radix_tree_lookup_slot(&dvnode->vfs_inode.i_mapping->i_pages,
+					      blkoff / PAGE_SIZE);
+		if (slot)
+			page = radix_tree_deref_slot(slot);
+		rcu_read_unlock();
 		if (!page) {
 			ret = -EIO;
 			break;
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 7d4f26198573..e887a9b24f4f 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -148,7 +148,7 @@ int afs_open(struct inode *inode, struct file *file)
 
 	if (file->f_flags & O_TRUNC)
 		set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
-	
+
 	file->private_data = af;
 	_leave(" = 0");
 	return 0;
@@ -185,24 +185,79 @@ int afs_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
+/*
+ * Make pages available as they're filled.  This function may not sleep.
+ */
+static void afs_readpages_page_done(const struct iov_iter *iter,
+				    const struct bio_vec *bv)
+{
+	struct page *page = bv->bv_page;
+	struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
+	struct afs_read *req = container_of(iter, struct afs_read, iter);
+
+	SetPageUptodate(page);
+
+	if (0 && afs_vnode_cache(vnode))
+		SetPageFsCache(page);
+	unlock_page(page);
+	put_page(page);
+	req->done_pages++;
+}
+
+/*
+ * Unlock the pages we were reading into.  We've got locks and refs on the
+ * first nr_pages pages.
+ */
+static void afs_file_read_cleanup(struct afs_read *req)
+{
+	struct radix_tree_iter iter;
+	struct address_space *mapping = req->iter.mapping;
+	struct page *page;
+	pgoff_t index = req->pos >> PAGE_SHIFT;
+	void **slot;
+
+	_enter("%lu,%u,%u,%zu",
+	       index, req->done_pages, req->nr_pages, iov_iter_count(&req->iter));
+
+	if (likely(req->done_pages >= req->nr_pages))
+		return;
+
+	rcu_read_lock();
+	radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) {
+		page = radix_tree_deref_slot(slot);
+		if (unlikely(!page))
+			continue;
+
+		BUG_ON(radix_tree_exception(page));
+		BUG_ON(PageCompound(page));
+		BUG_ON(page != *slot);
+		BUG_ON(page->mapping != req->iter.mapping);
+
+		if (req->error)
+			SetPageError(page);
+		unlock_page(page);
+		put_page(page);
+		req->done_pages++;
+		if (req->done_pages >= req->nr_pages)
+			break;
+	}
+
+	rcu_read_unlock();
+}
+
 /*
  * Dispose of a ref to a read record.
  */
 void afs_put_read(struct afs_read *req)
 {
-	int i;
-
 	if (refcount_dec_and_test(&req->usage)) {
-		for (i = 0; i < req->nr_pages; i++)
-			if (req->pages[i])
-				put_page(req->pages[i]);
-		if (req->pages != req->array)
-			kfree(req->pages);
+		if (req->cleanup)
+			req->cleanup(req);
 		kfree(req);
 	}
 }
 
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 /*
  * deal with notification that a page was read from the cache
  */
@@ -257,6 +312,22 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key *key, struct afs_read *de
 	return ret;
 }
 
+/*
+ * Clear the trailer after a short read.
+ */
+static void afs_clear_after_read(struct afs_vnode *vnode, struct afs_read *req,
+				 bool catch_page_done)
+{
+	if (req->actual_len >= req->len)
+		return;
+	iov_iter_mapping(&req->iter, READ, vnode->vfs_inode.i_mapping,
+			 req->pos + req->actual_len,
+			 req->len - req->actual_len);
+	if (catch_page_done)
+		req->iter.page_done = afs_readpages_page_done;
+	iov_iter_zero(req->len - req->actual_len, &req->iter);
+}
+
 /*
  * read page from file, directory or symlink, given a key to use
  */
@@ -277,7 +348,7 @@ int afs_page_filler(void *data, struct page *page)
 		goto error;
 
 	/* is it cached? */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	ret = fscache_read_or_alloc_page(vnode->cache,
 					 page,
 					 afs_file_readpage_read_complete,
@@ -301,8 +372,7 @@ int afs_page_filler(void *data, struct page *page)
 		_debug("cache said ENOBUFS");
 	default:
 	go_on:
-		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-			      GFP_KERNEL);
+		req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
 		if (!req)
 			goto enomem;
 
@@ -314,10 +384,11 @@ int afs_page_filler(void *data, struct page *page)
 		req->pos = (loff_t)page->index << PAGE_SHIFT;
 		req->len = PAGE_SIZE;
 		req->nr_pages = 1;
-		req->pages = req->array;
-		req->pages[0] = page;
 		get_page(page);
 
+		iov_iter_mapping(&req->iter, READ, page->mapping,
+				 (loff_t)page->index << PAGE_SHIFT, PAGE_SIZE);
+
 		/* read the contents of the file from the server into the
 		 * page */
 		ret = afs_fetch_data(vnode, key, req);
@@ -331,11 +402,6 @@ int afs_page_filler(void *data, struct page *page)
 				ret = -ESTALE;
 			}
 
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			BUG_ON(PageFsCache(page));
-
 			if (ret == -EINTR ||
 			    ret == -ENOMEM ||
 			    ret == -ERESTARTSYS ||
@@ -344,10 +410,11 @@ int afs_page_filler(void *data, struct page *page)
 			goto io_error;
 		}
 
+		afs_clear_after_read(vnode, req, false);
 		SetPageUptodate(page);
 
 		/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 		if (PageFsCache(page) &&
 		    fscache_write_page(vnode->cache, page, vnode->status.size,
 				       GFP_KERNEL) != 0) {
@@ -398,31 +465,39 @@ static int afs_readpage(struct file *file, struct page *page)
 	return ret;
 }
 
+#if 0
 /*
- * Make pages available as they're filled.
+ * Allow writing to a page to take place.  This function may not sleep.
  */
-static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)
+static void afs_clear_page_fscache_mark(const struct iov_iter *iter,
+					struct page *page)
 {
-#ifdef CONFIG_AFS_FSCACHE
-	struct afs_vnode *vnode = call->reply[0];
-#endif
-	struct page *page = req->pages[req->index];
+	ClearPageFsCache(page);
+}
 
-	req->pages[req->index] = NULL;
-	SetPageUptodate(page);
+static void afs_fscache_write_done(struct fscache_cookie *cookie,
+				   struct iov_iter *iter)
+{
+	struct afs_read *req = container_of(iter, struct afs_read, iter);
+
+	afs_put_read(req);
+}
+
+/*
+ * Write the read data to the cache.
+ */
+static void afs_readpages_write_to_cache(struct afs_read *req)
+{
+	struct afs_vnode *vnode = AFS_FS_I(req->iter.mapping->host);
 
-	/* send the page to the cache */
-#ifdef CONFIG_AFS_FSCACHE
-	if (PageFsCache(page) &&
-	    fscache_write_page(vnode->cache, page, vnode->status.size,
-			       GFP_KERNEL) != 0) {
-		fscache_uncache_page(vnode->cache, page);
-		BUG_ON(PageFsCache(page));
+	if (afs_vnode_cache(vnode)) {
+		req->iter.page_done = afs_clear_page_fscache_mark;
+		fscache_write(vnode->cache, &req->iter, req->pos,
+			      req->file_size, GFP_KERNEL,
+			      afs_fscache_write_done);
 	}
-#endif
-	unlock_page(page);
-	put_page(page);
 }
+#endif
 
 /*
  * Read a contiguous set of pages.
@@ -436,7 +511,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	struct page *first, *page;
 	struct key *key = afs_file_key(file);
 	pgoff_t index;
-	int ret, n, i;
+	int ret, n;
 
 	/* Count the number of contiguous pages at the front of the list.  Note
 	 * that the list goes prev-wards rather than next-wards.
@@ -452,20 +527,17 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		n++;
 	}
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,
-		      GFP_NOFS);
+	req = kzalloc(sizeof(struct afs_read), GFP_NOFS);
 	if (!req)
 		return -ENOMEM;
 
 	refcount_set(&req->usage, 1);
-	req->page_done = afs_readpages_page_done;
+	req->cleanup = afs_file_read_cleanup;
 	req->pos = first->index;
 	req->pos <<= PAGE_SHIFT;
-	req->pages = req->array;
 
-	/* Transfer the pages to the request.  We add them in until one fails
-	 * to add to the LRU and then we stop (as that'll make a hole in the
-	 * contiguous run.
+	/* Add pages to the LRU until it fails.  We keep the pages ref'd and
+	 * locked until the read is complete.
 	 *
 	 * Note that it's possible for the file size to change whilst we're
 	 * doing this, but we rely on the server returning less than we asked
@@ -478,15 +550,11 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		index = page->index;
 		if (add_to_page_cache_lru(page, mapping, index,
 					  readahead_gfp_mask(mapping))) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
 			put_page(page);
 			break;
 		}
 
-		req->pages[req->nr_pages++] = page;
-		req->len += PAGE_SIZE;
+		req->nr_pages++;
 	} while (req->nr_pages < n);
 
 	if (req->nr_pages == 0) {
@@ -494,33 +562,26 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 		return 0;
 	}
 
+	req->len = req->nr_pages * PAGE_SIZE;
+	iov_iter_mapping(&req->iter, READ, file->f_mapping, req->pos, req->len);
+	req->iter.page_done = afs_readpages_page_done;
+
 	ret = afs_fetch_data(vnode, key, req);
 	if (ret < 0)
 		goto error;
 
-	task_io_account_read(PAGE_SIZE * req->nr_pages);
-	afs_put_read(req);
+	afs_clear_after_read(vnode, req, true);
+	task_io_account_read(req->len);
 	return 0;
 
 error:
 	if (ret == -ENOENT) {
-		_debug("got NOENT from server"
-		       " - marking file deleted and stale");
+		_debug("got NOENT from server - marking file deleted and stale");
 		set_bit(AFS_VNODE_DELETED, &vnode->flags);
 		ret = -ESTALE;
 	}
 
-	for (i = 0; i < req->nr_pages; i++) {
-		page = req->pages[i];
-		if (page) {
-#ifdef CONFIG_AFS_FSCACHE
-			fscache_uncache_page(vnode->cache, page);
-#endif
-			SetPageError(page);
-			unlock_page(page);
-		}
-	}
-
+	req->error = true;
 	afs_put_read(req);
 	return ret;
 }
@@ -547,7 +608,7 @@ static int afs_readpages(struct file *file, struct address_space *mapping,
 	}
 
 	/* attempt to read as many of the pages as possible */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	ret = fscache_read_or_alloc_pages(vnode->cache,
 					  mapping,
 					  pages,
@@ -605,7 +666,7 @@ static void afs_invalidatepage(struct page *page, unsigned int offset,
 
 	/* we clean up only if the entire page is being invalidated */
 	if (offset == 0 && length == PAGE_SIZE) {
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 		if (PageFsCache(page)) {
 			struct afs_vnode *vnode = AFS_FS_I(page->mapping->host);
 			fscache_wait_on_page_write(vnode->cache, page);
@@ -640,7 +701,7 @@ static int afs_releasepage(struct page *page, gfp_t gfp_flags)
 
 	/* deny if page is being written to the cache and the caller hasn't
 	 * elected to wait */
-#ifdef CONFIG_AFS_FSCACHE
+#if 0 //def CONFIG_AFS_FSCACHE
 	if (!fscache_maybe_release_page(vnode->cache, page, gfp_flags)) {
 		_leave(" = F [cache busy]");
 		return 0;
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index d9a5815945dc..f0cef8e7b1af 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -20,12 +20,6 @@
 
 static const struct afs_fid afs_zero_fid;
 
-/*
- * We need somewhere to discard into in case the server helpfully returns more
- * than we asked for in FS.FetchData{,64}.
- */
-static u8 afs_discard_buffer[64];
-
 static inline void afs_use_fs_server(struct afs_call *call, struct afs_cb_interest *cbi)
 {
 	call->cbi = afs_get_cb_interest(cbi);
@@ -468,115 +462,82 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 	struct afs_vnode *vnode = call->reply[0];
 	struct afs_read *req = call->reply[2];
 	const __be32 *bp;
-	unsigned int size;
-	void *buffer;
 	int ret;
 
-	_enter("{%u,%zu/%u;%llu/%llu}",
-	       call->unmarshall, call->offset, call->count,
-	       req->remain, req->actual_len);
+	_enter("{%u,%zu/%llu}",
+	       call->unmarshall, iov_iter_count(&call->iter), req->actual_len);
 
 	switch (call->unmarshall) {
 	case 0:
 		req->actual_len = 0;
-		call->offset = 0;
 		call->unmarshall++;
 		if (call->operation_ID != FSFETCHDATA64) {
 			call->unmarshall++;
 			goto no_msw;
 		}
+		afs_extract_to_tmp(call);
 
 		/* extract the upper part of the returned data length of an
-		 * FSFETCHDATA64 op (which should always be 0 using this
-		 * client) */
+		 * FSFETCHDATA64 op.
+		 */
 	case 1:
 		_debug("extract data length (MSW)");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		req->actual_len = ntohl(call->tmp);
 		req->actual_len <<= 32;
-		call->offset = 0;
 		call->unmarshall++;
-
 	no_msw:
+		afs_extract_to_tmp(call);
+
 		/* extract the returned data length */
 	case 2:
 		_debug("extract data length");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		req->actual_len |= ntohl(call->tmp);
 		_debug("DATA length: %llu", req->actual_len);
 
-		req->remain = req->actual_len;
-		call->offset = req->pos & (PAGE_SIZE - 1);
-		req->index = 0;
 		if (req->actual_len == 0)
 			goto no_more_data;
 		call->unmarshall++;
-
-	begin_page:
-		ASSERTCMP(req->index, <, req->nr_pages);
-		if (req->remain > PAGE_SIZE - call->offset)
-			size = PAGE_SIZE - call->offset;
-		else
-			size = req->remain;
-		call->count = call->offset + size;
-		ASSERTCMP(call->count, <=, PAGE_SIZE);
-		req->remain -= size;
+		call->_iter = &req->iter;
+		iov_iter_truncate(&req->iter, req->actual_len);
 
 		/* extract the returned data */
 	case 3:
-		_debug("extract data %llu/%llu %zu/%u",
-		       req->remain, req->actual_len, call->offset, call->count);
+		_debug("extract data %zu/%llu",
+		       iov_iter_count(&call->iter), req->actual_len);
 
-		buffer = kmap(req->pages[req->index]);
-		ret = afs_extract_data(call, buffer, call->count, true);
-		kunmap(req->pages[req->index]);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
-		if (call->offset == PAGE_SIZE) {
-			if (req->page_done)
-				req->page_done(call, req);
-			req->index++;
-			if (req->remain > 0) {
-				call->offset = 0;
-				if (req->index >= req->nr_pages) {
-					call->unmarshall = 4;
-					goto begin_discard;
-				}
-				goto begin_page;
-			}
-		}
-		goto no_more_data;
+
+		call->_iter = &call->iter;
+		if (req->actual_len <= req->len)
+			goto no_more_data;
 
 		/* Discard any excess data the server gave us */
-	begin_discard:
+		iov_iter_discard(&call->iter, READ, req->actual_len - req->len);
 	case 4:
-		size = min_t(loff_t, sizeof(afs_discard_buffer), req->remain);
-		call->count = size;
-		_debug("extract discard %llu/%llu %zu/%u",
-		       req->remain, req->actual_len, call->offset, call->count);
-
-		call->offset = 0;
-		ret = afs_extract_data(call, afs_discard_buffer, call->count, true);
-		req->remain -= call->offset;
+		_debug("extract discard %zu/%llu",
+		       iov_iter_count(&call->iter), req->actual_len - req->len);
+
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
-		if (req->remain > 0)
-			goto begin_discard;
 
 	no_more_data:
-		call->offset = 0;
 		call->unmarshall = 5;
+		afs_extract_to_buf(call, (21 + 3 + 6) * 4);
 
 		/* extract the metadata */
 	case 5:
-		ret = afs_extract_data(call, call->buffer,
-				       (21 + 3 + 6) * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -589,22 +550,12 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		if (call->reply[1])
 			xdr_decode_AFSVolSync(&bp, call->reply[1]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 6:
 		break;
 	}
 
-	for (; req->index < req->nr_pages; req->index++) {
-		if (call->count < PAGE_SIZE)
-			zero_user_segment(req->pages[req->index],
-					  call->count, PAGE_SIZE);
-		if (req->page_done)
-			req->page_done(call, req);
-		call->count = 0;
-	}
-
 	_leave(" = 0 [done]");
 	return 0;
 }
@@ -700,6 +651,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
 	call->expected_version = vnode->status.data_version;
+	req->call_debug_id = call->debug_id;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -1598,31 +1550,31 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 {
 	const __be32 *bp;
 	char *p;
+	u32 size;
 	int ret;
 
 	_enter("{%u}", call->unmarshall);
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
 		call->unmarshall++;
+		afs_extract_to_buf(call, 12 * 4);
 
 		/* extract the returned status record */
 	case 1:
 		_debug("extract status");
-		ret = afs_extract_data(call, call->buffer,
-				       12 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		bp = call->buffer;
 		xdr_decode_AFSFetchVolumeStatus(&bp, call->reply[1]);
-		call->offset = 0;
 		call->unmarshall++;
+		afs_extract_to_tmp(call);
 
 		/* extract the volume name length */
 	case 2:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1631,46 +1583,26 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_volname_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the volume name */
 	case 3:
 		_debug("extract volname");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("volname '%s'", p);
-
-		call->offset = 0;
-		call->unmarshall++;
-
-		/* extract the volume name padding */
-		if ((call->count & 3) == 0) {
-			call->unmarshall++;
-			goto no_volname_padding;
-		}
-		call->count = 4 - (call->count & 3);
-
-	case 4:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, true);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
-	no_volname_padding:
 
 		/* extract the offline message length */
-	case 5:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+	case 4:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1679,46 +1611,27 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_offline_msg_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the offline message */
-	case 6:
+	case 5:
 		_debug("extract offline");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("offline '%s'", p);
 
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the offline message padding */
-		if ((call->count & 3) == 0) {
-			call->unmarshall++;
-			goto no_offline_padding;
-		}
-		call->count = 4 - (call->count & 3);
-
-	case 7:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, true);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
-		call->unmarshall++;
-	no_offline_padding:
-
 		/* extract the message of the day length */
-	case 8:
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+	case 6:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -1727,38 +1640,24 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		if (call->count >= AFSNAMEMAX)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_motd_len);
-		call->offset = 0;
+		size = (call->count + 3) & ~3; /* It's padded */
+		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
 		/* extract the message of the day */
-	case 9:
+	case 7:
 		_debug("extract motd");
-		if (call->count > 0) {
-			ret = afs_extract_data(call, call->reply[2],
-					       call->count, true);
-			if (ret < 0)
-				return ret;
-		}
+		ret = afs_extract_data(call, false);
+		if (ret < 0)
+			return ret;
 
 		p = call->reply[2];
 		p[call->count] = 0;
 		_debug("motd '%s'", p);
 
-		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the message of the day padding */
-		call->count = (4 - (call->count & 3)) & 3;
-
-	case 10:
-		ret = afs_extract_data(call, call->buffer,
-				       call->count, false);
-		if (ret < 0)
-			return ret;
-
-		call->offset = 0;
-		call->unmarshall++;
-	case 11:
+	case 8:
 		break;
 	}
 
@@ -2024,19 +1923,16 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 	u32 count;
 	int ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%zu}", call->unmarshall, iov_iter_count(&call->iter));
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the capabilities word count */
 	case 1:
-		ret = afs_extract_data(call, &call->tmp,
-				       1 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2044,24 +1940,17 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 
 		call->count = count;
 		call->count2 = count;
-		call->offset = 0;
+		iov_iter_discard(&call->iter, READ, count * sizeof(__be32));
 		call->unmarshall++;
 
 		/* Extract capabilities words */
 	case 2:
-		count = min(call->count, 16U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 16);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
 		/* TODO: Examine capabilities */
 
-		call->count -= count;
-		if (call->count > 0)
-			goto again;
-		call->offset = 0;
 		call->unmarshall++;
 		break;
 	}
@@ -2215,13 +2104,13 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the file status count and array in two steps */
 	case 1:
 		_debug("extract status count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2234,11 +2123,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->count = 0;
 		call->unmarshall++;
 	more_counts:
-		call->offset = 0;
+		afs_extract_to_buf(call, 21 * sizeof(__be32));
 
 	case 2:
 		_debug("extract status array %u", call->count);
-		ret = afs_extract_data(call, call->buffer, 21 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2256,12 +2145,12 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 		call->count = 0;
 		call->unmarshall++;
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 
 		/* Extract the callback count and array in two steps */
 	case 3:
 		_debug("extract CB count");
-		ret = afs_extract_data(call, &call->tmp, 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2273,11 +2162,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->count = 0;
 		call->unmarshall++;
 	more_cbs:
-		call->offset = 0;
+		afs_extract_to_buf(call, 3 * sizeof(__be32));
 
 	case 4:
 		_debug("extract CB array");
-		ret = afs_extract_data(call, call->buffer, 3 * 4, true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -2294,11 +2183,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		if (call->count < call->count2)
 			goto more_cbs;
 
-		call->offset = 0;
+		afs_extract_to_buf(call, 6 * sizeof(__be32));
 		call->unmarshall++;
 
 	case 5:
-		ret = afs_extract_data(call, call->buffer, 6 * 4, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
@@ -2306,7 +2195,6 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		if (call->reply[3])
 			xdr_decode_AFSVolSync(&bp, call->reply[3]);
 
-		call->offset = 0;
 		call->unmarshall++;
 
 	case 6:
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 457a8f76b6a2..997ab8350dfe 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -96,11 +96,16 @@ struct afs_call {
 	struct afs_cb_interest	*cbi;		/* Callback interest for server used */
 	void			*request;	/* request data (first part) */
 	struct address_space	*mapping;	/* Pages being written from */
+	struct iov_iter		iter;		/* Buffer iterator */
+	struct iov_iter		*_iter;		/* Iterator currently in use */
+	union {	/* Convenience for ->iter */
+		struct kvec	kvec[1];
+		struct bio_vec	bvec[1];
+	};
 	void			*buffer;	/* reply receive buffer */
 	void			*reply[4];	/* Where to put the reply */
 	pgoff_t			first;		/* first page in mapping to deal with */
 	pgoff_t			last;		/* last page in mapping to deal with */
-	size_t			offset;		/* offset into received data store */
 	atomic_t		usage;
 	enum afs_call_state	state;
 	spinlock_t		state_lock;
@@ -177,15 +182,15 @@ struct afs_read {
 	loff_t			pos;		/* Where to start reading */
 	loff_t			len;		/* How much we're asking for */
 	loff_t			actual_len;	/* How much we're actually getting */
-	loff_t			remain;		/* Amount remaining */
 	loff_t			file_size;	/* File size returned by server */
 	afs_dataversion_t	data_version;	/* Version number returned by server */
 	refcount_t		usage;
-	unsigned int		index;		/* Which page we're reading into */
 	unsigned int		nr_pages;
-	void (*page_done)(struct afs_call *, struct afs_read *);
-	struct page		**pages;
-	struct page		*array[];
+	unsigned int		done_pages;
+	bool			error;
+	unsigned int		call_debug_id;
+	void (*cleanup)(struct afs_read *);
+	struct iov_iter		iter;		/* Buffer */
 };
 
 /*
@@ -548,6 +553,15 @@ struct afs_vnode {
 	afs_callback_type_t	cb_type;	/* type of callback */
 };
 
+static inline struct fscache_cookie *afs_vnode_cache(struct afs_vnode *vnode)
+{
+#ifdef CONFIG_AFS_FSCACHE
+	return vnode->cache;
+#else
+	return NULL;
+#endif
+}
+
 /*
  * cached security record for one user's attempt to access a vnode
  */
@@ -928,12 +942,34 @@ extern struct afs_call *afs_alloc_flat_call(struct afs_net *,
 extern void afs_flat_call_destructor(struct afs_call *);
 extern void afs_send_empty_reply(struct afs_call *);
 extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
-extern int afs_extract_data(struct afs_call *, void *, size_t, bool);
+extern int afs_extract_data(struct afs_call *, bool);
 extern int afs_protocol_error(struct afs_call *, int, enum afs_eproto_cause);
 
+static inline void afs_extract_begin(struct afs_call *call, void *buf, size_t size)
+{
+	call->kvec[0].iov_base = buf;
+	call->kvec[0].iov_len = size;
+	iov_iter_kvec(&call->iter, READ, call->kvec, 1, size);
+}
+
+static inline void afs_extract_to_tmp(struct afs_call *call)
+{
+	afs_extract_begin(call, &call->tmp, sizeof(call->tmp));
+}
+
+static inline void afs_extract_discard(struct afs_call *call, size_t size)
+{
+	iov_iter_discard(&call->iter, READ, size);
+}
+
+static inline void afs_extract_to_buf(struct afs_call *call, size_t size)
+{
+	afs_extract_begin(call, call->buffer, size);
+}
+
 static inline int afs_transfer_reply(struct afs_call *call)
 {
-	return afs_extract_data(call, call->buffer, call->reply_max, false);
+	return afs_extract_data(call, false);
 }
 
 static inline bool afs_check_call_state(struct afs_call *call,
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 20199f2b2c31..966e30f30cbb 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -143,6 +143,7 @@ static struct afs_call *afs_alloc_call(struct afs_net *net,
 	INIT_WORK(&call->async_work, afs_process_async_call);
 	init_waitqueue_head(&call->waitq);
 	spin_lock_init(&call->state_lock);
+	call->_iter = &call->iter;
 
 	o = atomic_inc_return(&net->nr_outstanding_calls);
 	trace_afs_call(call, afs_call_trace_alloc, 1, o,
@@ -233,6 +234,7 @@ struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 			goto nomem_free;
 	}
 
+	afs_extract_to_buf(call, call->reply_max);
 	call->operation_ID = type->op;
 	init_waitqueue_head(&call->waitq);
 	return call;
@@ -465,14 +467,12 @@ static void afs_deliver_to_call(struct afs_call *call)
 	       state == AFS_CALL_SV_AWAIT_ACK
 	       ) {
 		if (state == AFS_CALL_SV_AWAIT_ACK) {
-			struct iov_iter iter;
-
-			iov_iter_kvec(&iter, READ, NULL, 0, 0);
+			iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
 			ret = rxrpc_kernel_recv_data(call->net->socket,
-						     call->rxcall, &iter, false,
-						     &remote_abort,
+						     call->rxcall, &call->iter,
+						     false, &remote_abort,
 						     &call->service_id);
-			trace_afs_recv_data(call, 0, 0, false, ret);
+			trace_afs_receive_data(call, &call->iter, false, ret);
 
 			if (ret == -EINPROGRESS || ret == -EAGAIN)
 				return;
@@ -516,7 +516,7 @@ static void afs_deliver_to_call(struct afs_call *call)
 			if (state != AFS_CALL_CL_AWAIT_REPLY)
 				abort_code = RXGEN_SS_UNMARSHAL;
 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
-						abort_code, -EBADMSG, "KUM");
+						abort_code, ret, "KUM");
 			goto local_abort;
 		}
 	}
@@ -729,6 +729,7 @@ void afs_charge_preallocation(struct work_struct *work)
 			call->async = true;
 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
 			init_waitqueue_head(&call->waitq);
+			afs_extract_to_tmp(call);
 		}
 
 		if (rxrpc_kernel_charge_accept(net->socket,
@@ -774,18 +775,15 @@ static int afs_deliver_cm_op_id(struct afs_call *call)
 {
 	int ret;
 
-	_enter("{%zu}", call->offset);
-
-	ASSERTCMP(call->offset, <, 4);
+	_enter("{%zu}", iov_iter_count(call->_iter));
 
 	/* the operation ID forms the first four bytes of the request data */
-	ret = afs_extract_data(call, &call->tmp, 4, true);
+	ret = afs_extract_data(call, true);
 	if (ret < 0)
 		return ret;
 
 	call->operation_ID = ntohl(call->tmp);
 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
-	call->offset = 0;
 
 	/* ask the cache manager to route the call (it'll change the call type
 	 * if successful) */
@@ -889,30 +887,19 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 /*
  * Extract a piece of data from the received data socket buffers.
  */
-int afs_extract_data(struct afs_call *call, void *buf, size_t count,
-		     bool want_more)
+int afs_extract_data(struct afs_call *call, bool want_more)
 {
 	struct afs_net *net = call->net;
-	struct iov_iter iter;
-	struct kvec iov;
+	struct iov_iter *iter = call->_iter;
 	enum afs_call_state state;
 	u32 remote_abort = 0;
 	int ret;
 
-	_enter("{%s,%zu},,%zu,%d",
-	       call->type->name, call->offset, count, want_more);
-
-	ASSERTCMP(call->offset, <=, count);
-
-	iov.iov_base = buf + call->offset;
-	iov.iov_len = count - call->offset;
-	iov_iter_kvec(&iter, READ, &iov, 1, count - call->offset);
+	_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
 
-	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, &iter,
+	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 				     want_more, &remote_abort,
 				     &call->service_id);
-	call->offset += (count - call->offset) - iov_iter_count(&iter);
-	trace_afs_recv_data(call, count, call->offset, want_more, ret);
 	if (ret == 0 || ret == -EAGAIN)
 		return ret;
 
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index d0f95c4ab05e..e18c51742daa 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -187,19 +187,18 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 	u32 uniquifier, nentries, count;
 	int i, ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%zu/%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_buf(call,
+				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
 		call->unmarshall++;
 
 		/* Extract the returned uuid, uniquifier, nentries and blkaddrs size */
 	case 1:
-		ret = afs_extract_data(call, call->buffer,
-				       sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -216,28 +215,28 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->reply[0] = alist;
 		call->count = count;
 		call->count2 = nentries;
-		call->offset = 0;
 		call->unmarshall++;
 
+	more_entries:
+		count = min(call->count, 4U);
+		afs_extract_to_buf(call, count * sizeof(__be32));
+
 		/* Extract entries */
 	case 2:
-		count = min(call->count, 4U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 4);
+		ret = afs_extract_data(call, call->count > 4);
 		if (ret < 0)
 			return ret;
 
 		alist = call->reply[0];
 		bp = call->buffer;
+		count = min(call->count, 4U);
 		for (i = 0; i < count; i++)
 			if (alist->nr_addrs < call->count2)
 				afs_merge_fs_addr4(alist, *bp++, AFS_FS_PORT);
 
 		call->count -= count;
 		if (call->count > 0)
-			goto again;
-		call->offset = 0;
+			goto more_entries;
 		call->unmarshall++;
 		break;
 	}
@@ -318,44 +317,35 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 	u32 count;
 	int ret;
 
-	_enter("{%u,%zu/%u}", call->unmarshall, call->offset, call->count);
+	_enter("{%u,%zu/%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
 		/* Extract the capabilities word count */
 	case 1:
-		ret = afs_extract_data(call, &call->tmp,
-				       1 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		count = ntohl(call->tmp);
-
 		call->count = count;
 		call->count2 = count;
-		call->offset = 0;
+
 		call->unmarshall++;
+		afs_extract_discard(call, count * sizeof(__be32));
 
 		/* Extract capabilities words */
 	case 2:
-		count = min(call->count, 16U);
-		ret = afs_extract_data(call, call->buffer,
-				       count * sizeof(__be32),
-				       call->count > 16);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 
 		/* TODO: Examine capabilities */
 
-		call->count -= count;
-		if (call->count > 0)
-			goto again;
-		call->offset = 0;
 		call->unmarshall++;
 		break;
 	}
@@ -426,22 +416,19 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 	u32 uniquifier, size;
 	int ret;
 
-	_enter("{%u,%zu/%u,%u}", call->unmarshall, call->offset, call->count, call->count2);
+	_enter("{%u,%zu,%u}",
+	       call->unmarshall, iov_iter_count(call->_iter), call->count2);
 
-again:
 	switch (call->unmarshall) {
 	case 0:
-		call->offset = 0;
+		afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32));
 		call->unmarshall = 1;
 
 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
 		 * either the first fsEndpoint type or the volEndpoints
 		 * count if there are no fsEndpoints. */
 	case 1:
-		ret = afs_extract_data(call, call->buffer,
-				       sizeof(uuid_t) +
-				       3 * sizeof(__be32),
-				       true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -459,15 +446,11 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			return -ENOMEM;
 		alist->version = uniquifier;
 		call->reply[0] = alist;
-		call->offset = 0;
 
 		if (call->count == 0)
 			goto extract_volendpoints;
 
-		call->unmarshall = 2;
-
-		/* Extract fsEndpoints[] entries */
-	case 2:
+	next_fsendpoint:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			size = sizeof(__be32) * (1 + 1 + 1);
@@ -481,7 +464,12 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		}
 
 		size += sizeof(__be32);
-		ret = afs_extract_data(call, call->buffer, size, true);
+		afs_extract_to_buf(call, size);
+		call->unmarshall = 2;
+
+		/* Extract fsEndpoints[] entries */
+	case 2:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -512,10 +500,9 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 */
 		call->count2 = ntohl(*bp++);
 
-		call->offset = 0;
 		call->count--;
 		if (call->count > 0)
-			goto again;
+			goto next_fsendpoint;
 
 	extract_volendpoints:
 		/* Extract the list of volEndpoints. */
@@ -526,6 +513,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 			return afs_protocol_error(call, -EBADMSG,
 						  afs_eproto_yvl_vlendpt_type);
 
+		afs_extract_to_buf(call, 1 * sizeof(__be32));
 		call->unmarshall = 3;
 
 		/* Extract the type of volEndpoints[0].  Normally we would
@@ -533,17 +521,14 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 * data of the current one, but this is the first...
 		 */
 	case 3:
-		ret = afs_extract_data(call, call->buffer, sizeof(__be32), true);
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
 		bp = call->buffer;
-		call->count2 = ntohl(*bp++);
-		call->offset = 0;
-		call->unmarshall = 4;
 
-		/* Extract volEndpoints[] entries */
-	case 4:
+	next_volendpoint:
+		call->count2 = ntohl(*bp++);
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
 			size = sizeof(__be32) * (1 + 1 + 1);
@@ -557,8 +542,13 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		}
 
 		if (call->count > 1)
-			size += sizeof(__be32);
-		ret = afs_extract_data(call, call->buffer, size, true);
+			size += sizeof(__be32); /* Get next type too */
+		afs_extract_to_buf(call, size);
+		call->unmarshall = 4;
+
+		/* Extract volEndpoints[] entries */
+	case 4:
+		ret = afs_extract_data(call, true);
 		if (ret < 0)
 			return ret;
 
@@ -584,19 +574,17 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		/* Got either the type of the next entry or the count of
 		 * volEndpoints if no more fsEndpoints.
 		 */
-		call->offset = 0;
 		call->count--;
-		if (call->count > 0) {
-			call->count2 = ntohl(*bp++);
-			goto again;
-		}
+		if (call->count > 0)
+			goto next_volendpoint;
 
 	end:
+		afs_extract_discard(call, 0);
 		call->unmarshall = 5;
 
 		/* Done */
 	case 5:
-		ret = afs_extract_data(call, call->buffer, 0, false);
+		ret = afs_extract_data(call, false);
 		if (ret < 0)
 			return ret;
 		call->unmarshall = 6;
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 19c04caf3c01..d07e7f29f50a 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -37,8 +37,7 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 
 	_enter(",,%llu", (unsigned long long)pos);
 
-	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
-		      GFP_KERNEL);
+	req = kzalloc(sizeof(struct afs_read), GFP_KERNEL);
 	if (!req)
 		return -ENOMEM;
 
@@ -46,9 +45,8 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
 	req->pos = pos;
 	req->len = len;
 	req->nr_pages = 1;
-	req->pages = req->array;
-	req->pages[0] = page;
-	get_page(page);
+	iov_iter_mapping(&req->iter, READ, vnode->vfs_inode.i_mapping,
+			 pos, len);
 
 	ret = afs_fetch_data(vnode, key, req);
 	afs_put_read(req);
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 84b90a79d75a..d99294c75e9a 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -218,6 +218,9 @@ extern int __fscache_read_or_alloc_pages(struct fscache_cookie *,
 					 gfp_t);
 extern int __fscache_alloc_page(struct fscache_cookie *, struct page *, gfp_t);
 extern int __fscache_write_page(struct fscache_cookie *, struct page *, loff_t, gfp_t);
+extern int __fscache_write(struct fscache_cookie *, struct iov_iter *,
+			   loff_t, loff_t, gfp_t,
+			   void (*)(struct fscache_cookie *, struct iov_iter *));
 extern void __fscache_uncache_page(struct fscache_cookie *, struct page *);
 extern bool __fscache_check_page_write(struct fscache_cookie *, struct page *);
 extern void __fscache_wait_on_page_write(struct fscache_cookie *, struct page *);
@@ -655,6 +658,34 @@ void fscache_readpages_cancel(struct fscache_cookie *cookie,
 		__fscache_readpages_cancel(cookie, pages);
 }
 
+/**
+ * fscache_write - Request storage of data in the cache
+ * @cookie: The cookie representing the cache object
+ * @iter: The data to store
+ * @pos: The position in the cached data
+ * @object_size: Updated size of object
+ * @gfp: The conditions under which memory allocation should be made
+ * @done: Called upon operation completion
+ *
+ * Request the data described by the iterator be written into the cache.  This
+ * request may be ignored if insufficient space exists in the cache, in which
+ * case -ENOBUFS will be returned.
+ *
+ * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * description.
+ */
+static inline
+int fscache_write(struct fscache_cookie *cookie, struct iov_iter *iter,
+		  loff_t pos, loff_t object_size, gfp_t gfp,
+		  void (*done)(struct fscache_cookie *cookie,
+			       struct iov_iter *iter))
+{
+	if (fscache_cookie_valid(cookie))
+		return __fscache_write(cookie, iter, pos, object_size, gfp, done);
+	else
+		return -ENOBUFS;
+}
+
 /**
  * fscache_write_page - Request storage of a page in the cache
  * @cookie: The cookie representing the cache object
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 5c60ade2c7d8..5e0f8dcede26 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -207,17 +207,16 @@ afs_edit_dir_reasons;
 #define EM(a, b)	{ a, b },
 #define E_(a, b)	{ a, b }
 
-TRACE_EVENT(afs_recv_data,
-	    TP_PROTO(struct afs_call *call, unsigned count, unsigned offset,
+TRACE_EVENT(afs_receive_data,
+	    TP_PROTO(struct afs_call *call, struct iov_iter *iter,
 		     bool want_more, int ret),
 
-	    TP_ARGS(call, count, offset, want_more, ret),
+	    TP_ARGS(call, iter, want_more, ret),
 
 	    TP_STRUCT__entry(
+		    __field(loff_t,			remain		)
 		    __field(unsigned int,		call		)
 		    __field(enum afs_call_state,	state		)
-		    __field(unsigned int,		count		)
-		    __field(unsigned int,		offset		)
 		    __field(unsigned short,		unmarshall	)
 		    __field(bool,			want_more	)
 		    __field(int,			ret		)
@@ -227,17 +226,18 @@ TRACE_EVENT(afs_recv_data,
 		    __entry->call	= call->debug_id;
 		    __entry->state	= call->state;
 		    __entry->unmarshall	= call->unmarshall;
-		    __entry->count	= count;
-		    __entry->offset	= offset;
+		    __entry->remain	= iov_iter_count(iter);
 		    __entry->want_more	= want_more;
 		    __entry->ret	= ret;
 			   ),
 
-	    TP_printk("c=%08x s=%u u=%u %u/%u wm=%u ret=%d",
+	    TP_printk("c=%08x r=%llu u=%u w=%u s=%u ret=%d",
 		      __entry->call,
-		      __entry->state, __entry->unmarshall,
-		      __entry->offset, __entry->count,
-		      __entry->want_more, __entry->ret)
+		      __entry->remain,
+		      __entry->unmarshall,
+		      __entry->want_more,
+		      __entry->state,
+		      __entry->ret)
 	    );
 
 TRACE_EVENT(afs_notify_call,

^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2018-09-13 21:02 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-06 13:16 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
2018-08-06 13:16 ` [PATCH 01/10] iov_iter: Separate type from direction and use accessor functions David Howells
2018-08-06 13:16 ` [PATCH 02/10] iov_iter: Renumber the ITER_* constants in uio.h David Howells
2018-08-06 13:16 ` [PATCH 03/10] iov_iter: Make count and iov_offset loff_t not size_t David Howells
2018-08-06 13:17 ` [PATCH 04/10] iov_iter: Add mapping and discard iterator types David Howells
2018-08-06 13:17 ` [PATCH 05/10] afs: Better tracing of protocol errors David Howells
2018-08-06 13:17 ` [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data() David Howells
2018-08-06 13:17 ` [PATCH 07/10] afs: Use ITER_MAPPING for writing David Howells
2018-08-06 13:17 ` [PATCH 08/10] afs: Add O_DIRECT read support David Howells
2018-08-06 13:17 ` [PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors David Howells
2018-08-06 13:17 ` [PATCH 10/10] afs: Don't invoke the server to read data beyond EOF David Howells
2018-09-13 15:51 [PATCH 00/10] iov_iter: Add new iters and use with AFS David Howells
2018-09-13 15:52 ` [PATCH 06/10] afs: Set up the iov_iter before calling afs_extract_data() David Howells

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