afs: Introduce an afs_get_read() refcount helper

Introduce an afs_get_read() helper to get a reference on an afs_read
object.
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/fsclient.c

@@ -490,7 +490,7 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc,
 	call->key = fc->key;
 	call->out_scb = scb;
 	call->out_volsync = NULL;
-	call->read_request = req;
+	call->read_request = afs_get_read(req);
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -503,7 +503,6 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc,
 	bp[6] = 0;
 	bp[7] = htonl(lower_32_bits(req->len));
 
-	refcount_inc(&req->usage);
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
 	afs_set_fc_call(call, fc);
@@ -540,7 +539,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc,
 	call->key = fc->key;
 	call->out_scb = scb;
 	call->out_volsync = NULL;
-	call->read_request = req;
+	call->read_request = afs_get_read(req);
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -551,7 +550,6 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc,
 	bp[4] = htonl(lower_32_bits(req->pos));
 	bp[5] = htonl(lower_32_bits(req->len));
 
-	refcount_inc(&req->usage);
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
 	afs_set_fc_call(call, fc);

fs/afs/internal.h

@@ -934,6 +934,12 @@ extern int afs_fetch_data(struct afs_vnode *, struct key *, struct afs_read *);
 extern int afs_page_filler(void *, struct page *);
 extern void afs_put_read(struct afs_read *);
 
+static inline struct afs_read *afs_get_read(struct afs_read *req)
+{
+	refcount_inc(&req->usage);
+	return req;
+}
+
 /*
  * flock.c
  */

fs/afs/yfsclient.c

@@ -605,7 +605,7 @@ int yfs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_status_cb *scb,
 	call->key = fc->key;
 	call->out_scb = scb;
 	call->out_volsync = NULL;
-	call->read_request = req;
+	call->read_request = afs_get_read(req);
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -616,7 +616,6 @@ int yfs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_status_cb *scb,
 	bp = xdr_encode_u64(bp, req->len);
 	yfs_check_req(call, bp);
 
-	refcount_inc(&req->usage);
 	afs_use_fs_server(call, fc->cbi);
 	trace_afs_make_fs_call(call, &vnode->fid);
 	afs_set_fc_call(call, fc);