fuse: categorize fuse_get_req()

The patch categorizes all fuse_get_req() invocations into two categories:
 - fuse_get_req_nopages(fc) - when caller doesn't care about req->pages
 - fuse_get_req(fc, n) - when caller need n page pointers (n > 0)

Adding fuse_get_req_nopages() helps to avoid numerous fuse_get_req(fc, 0)
scattered over code. Now it's clear from the first glance when a caller need
fuse_req with page pointers.

The patch doesn't make any logic changes. In multi-page case, it silly
allocates array of FUSE_MAX_PAGES_PER_REQ page pointers. This will be amended
by future patches.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index dcc1e52..d04bcc5 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -178,7 +178,7 @@
 			return -ECHILD;
 
 		fc = get_fuse_conn(inode);
-		req = fuse_get_req(fc);
+		req = fuse_get_req_nopages(fc);
 		if (IS_ERR(req))
 			return 0;
 
@@ -271,7 +271,7 @@
 	if (name->len > FUSE_NAME_MAX)
 		goto out;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	err = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out;
@@ -391,7 +391,7 @@
 	if (!forget)
 		goto out_err;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	err = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out_put_forget_req;
@@ -592,7 +592,7 @@
 {
 	struct fuse_mknod_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -623,7 +623,7 @@
 {
 	struct fuse_mkdir_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -647,7 +647,7 @@
 {
 	struct fuse_conn *fc = get_fuse_conn(dir);
 	unsigned len = strlen(link) + 1;
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -664,7 +664,7 @@
 {
 	int err;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -696,7 +696,7 @@
 {
 	int err;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -723,7 +723,7 @@
 	int err;
 	struct fuse_rename_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(olddir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -776,7 +776,7 @@
 	struct fuse_link_in inarg;
 	struct inode *inode = entry->d_inode;
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -848,7 +848,7 @@
 	struct fuse_req *req;
 	u64 attr_version;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1029,7 +1029,7 @@
 	if (fc->no_access)
 		return 0;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1305,7 +1305,7 @@
 	if (is_bad_inode(inode))
 		return -EIO;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req(fc, 1);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1349,7 +1349,7 @@
 {
 	struct inode *inode = dentry->d_inode;
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	char *link;
 
 	if (IS_ERR(req))
@@ -1562,7 +1562,7 @@
 	if (attr->ia_valid & ATTR_SIZE)
 		is_truncate = true;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1670,7 +1670,7 @@
 	if (fc->no_setxattr)
 		return -EOPNOTSUPP;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1709,7 +1709,7 @@
 	if (fc->no_getxattr)
 		return -EOPNOTSUPP;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1761,7 +1761,7 @@
 	if (fc->no_listxattr)
 		return -EOPNOTSUPP;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1806,7 +1806,7 @@
 	if (fc->no_removexattr)
 		return -EOPNOTSUPP;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);