CIFS: Simplify SMB2_open code path

by passing a filename to a separate iovec regardless of its length.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>

2 files changed, 25 insertions, 36 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 4c046a5b81af..9a35dcda9099 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -894,7 +894,7 @@ SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path,
         __le16 *copy_path = NULL;
         int copy_size;
         int rc = 0;
-        int num_iovecs = 2;
+        unsigned int num_iovecs = 2;
         __u32 file_attributes = 0;
 
         cifs_dbg(FYI, "create/open\n");
@@ -919,47 +919,36 @@ SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path,
         req->CreateDisposition = cpu_to_le32(create_disposition);
         req->CreateOptions = cpu_to_le32(create_options & CREATE_OPTIONS_MASK);
         uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
-        req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req)
-                        - 8 /* pad */ - 4 /* do not count rfc1001 len field */);
+        /* do not count rfc1001 len field */
+        req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req) - 4);
 
         iov[0].iov_base = (char *)req;
         /* 4 for rfc1002 length field */
         iov[0].iov_len = get_rfc1002_length(req) + 4;
 
         /* MUST set path len (NameLength) to 0 opening root of share */
-        if (uni_path_len >= 4) {
-                req->NameLength = cpu_to_le16(uni_path_len - 2);
-                /* -1 since last byte is buf[0] which is sent below (path) */
-                iov[0].iov_len--;
-                if (uni_path_len % 8 != 0) {
-                        copy_size = uni_path_len / 8 * 8;
-                        if (copy_size < uni_path_len)
-                                copy_size += 8;
-
-                        copy_path = kzalloc(copy_size, GFP_KERNEL);
-                        if (!copy_path)
-                                return -ENOMEM;
-                        memcpy((char *)copy_path, (const char *)path,
-                                uni_path_len);
-                        uni_path_len = copy_size;
-                        path = copy_path;
-                }
-
-                iov[1].iov_len = uni_path_len;
-                iov[1].iov_base = path;
-                /*
-                 * -1 since last byte is buf[0] which was counted in
-                 * smb2_buf_len.
-                 */
-                inc_rfc1001_len(req, uni_path_len - 1);
-        } else {
-                iov[0].iov_len += 7;
-                req->hdr.smb2_buf_length = cpu_to_be32(be32_to_cpu(
-                                req->hdr.smb2_buf_length) + 8 - 1);
-                num_iovecs = 1;
-                req->NameLength = 0;
+        req->NameLength = cpu_to_le16(uni_path_len - 2);
+        /* -1 since last byte is buf[0] which is sent below (path) */
+        iov[0].iov_len--;
+        if (uni_path_len % 8 != 0) {
+                copy_size = uni_path_len / 8 * 8;
+                if (copy_size < uni_path_len)
+                        copy_size += 8;
+
+                copy_path = kzalloc(copy_size, GFP_KERNEL);
+                if (!copy_path)
+                        return -ENOMEM;
+                memcpy((char *)copy_path, (const char *)path,
+                        uni_path_len);
+                uni_path_len = copy_size;
+                path = copy_path;
         }
 
+        iov[1].iov_len = uni_path_len;
+        iov[1].iov_base = path;
+        /* -1 since last byte is buf[0] which was counted in smb2_buf_len */
+        inc_rfc1001_len(req, uni_path_len - 1);
+
         if (!server->oplocks)
                 *oplock = SMB2_OPLOCK_LEVEL_NONE;
 
@@ -976,7 +965,7 @@ SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path,
                 iov[num_iovecs].iov_len = sizeof(struct create_lease);
                 req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_LEASE;
                 req->CreateContextsOffset = cpu_to_le32(
-                        sizeof(struct smb2_create_req) - 4 - 8 +
+                        sizeof(struct smb2_create_req) - 4 +
                         iov[num_iovecs-1].iov_len);
                 req->CreateContextsLength = cpu_to_le32(
                         sizeof(struct create_lease));
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index f31043b26bd3..8b1025f6f0da 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -428,7 +428,7 @@ struct smb2_create_req {
         __le16 NameLength;
         __le32 CreateContextsOffset;
         __le32 CreateContextsLength;
-        __u8   Buffer[8];
+        __u8   Buffer[0];
 } __packed;
 
 struct smb2_create_rsp {