three small SMB3 fixes: 2 leaks and a rename bug

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Merge tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small SMB3 fixes (all for stable as well): two leaks and a
  rename bug"

* tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix page reference leak with readv/writev
  cifs: do not attempt cifs operation on smb2+ rename error
  cifs: fix memory leak in SMB2_read

fs/cifs/file.c

@@ -2877,7 +2877,6 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
 	struct cifs_tcon *tcon;
 	struct cifs_sb_info *cifs_sb;
 	struct dentry *dentry = ctx->cfile->dentry;
-	unsigned int i;
 	int rc;
 
 	tcon = tlink_tcon(ctx->cfile->tlink);
@@ -2941,10 +2940,6 @@ restart_loop:
 		kref_put(&wdata->refcount, cifs_uncached_writedata_release);
 	}
 
-	if (!ctx->direct_io)
-		for (i = 0; i < ctx->npages; i++)
-			put_page(ctx->bv[i].bv_page);
-
 	cifs_stats_bytes_written(tcon, ctx->total_len);
 	set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags);
 
@@ -3582,7 +3577,6 @@ collect_uncached_read_data(struct cifs_aio_ctx *ctx)
 	struct iov_iter *to = &ctx->iter;
 	struct cifs_sb_info *cifs_sb;
 	struct cifs_tcon *tcon;
-	unsigned int i;
 	int rc;
 
 	tcon = tlink_tcon(ctx->cfile->tlink);
@@ -3666,15 +3660,8 @@ again:
 		kref_put(&rdata->refcount, cifs_uncached_readdata_release);
 	}
 
-	if (!ctx->direct_io) {
-		for (i = 0; i < ctx->npages; i++) {
-			if (ctx->should_dirty)
-				set_page_dirty(ctx->bv[i].bv_page);
-			put_page(ctx->bv[i].bv_page);
-		}
-
+	if (!ctx->direct_io)
 		ctx->total_len = ctx->len - iov_iter_count(to);
-	}
 
 	/* mask nodata case */
 	if (rc == -ENODATA)

fs/cifs/inode.c

@@ -1735,6 +1735,10 @@ cifs_do_rename(const unsigned int xid, struct dentry *from_dentry,
 	if (rc == 0 || rc != -EBUSY)
 		goto do_rename_exit;
 
+	/* Don't fall back to using SMB on SMB 2+ mount */
+	if (server->vals->protocol_id != 0)
+		goto do_rename_exit;
+
 	/* open-file renames don't work across directories */
 	if (to_dentry->d_parent != from_dentry->d_parent)
 		goto do_rename_exit;

fs/cifs/misc.c

@@ -789,6 +789,11 @@ cifs_aio_ctx_alloc(void)
 {
 	struct cifs_aio_ctx *ctx;
 
+	/*
+	 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
+	 * to false so that we know when we have to unreference pages within
+	 * cifs_aio_ctx_release()
+	 */
 	ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
 	if (!ctx)
 		return NULL;
@@ -807,7 +812,23 @@ cifs_aio_ctx_release(struct kref *refcount)
 					struct cifs_aio_ctx, refcount);
 
 	cifsFileInfo_put(ctx->cfile);
-	kvfree(ctx->bv);
+
+	/*
+	 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
+	 * which means that iov_iter_get_pages() was a success and thus that
+	 * we have taken reference on pages.
+	 */
+	if (ctx->bv) {
+		unsigned i;
+
+		for (i = 0; i < ctx->npages; i++) {
+			if (ctx->should_dirty)
+				set_page_dirty(ctx->bv[i].bv_page);
+			put_page(ctx->bv[i].bv_page);
+		}
+		kvfree(ctx->bv);
+	}
+
 	kfree(ctx);
 }
 

fs/cifs/smb2pdu.c

@@ -3466,6 +3466,7 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
 				    io_parms->tcon->tid, ses->Suid,
 				    io_parms->offset, 0);
 		free_rsp_buf(resp_buftype, rsp_iov.iov_base);
+		cifs_small_buf_release(req);
 		return rc == -ENODATA ? 0 : rc;
 	} else
 		trace_smb3_read_done(xid, req->PersistentFileId,