+/*
+ * qemu_io_alloc_from_file()
+ *
+ * Allocates the buffer and populates it with the content of the given file
+ * up to @len bytes. If the file length is less than @len, then the buffer
+ * is populated with the file content cyclically.
+ *
+ * @blk - the block backend where the buffer content is going to be written to
+ * @len - the buffer length
+ * @file_name - the file to read the content from
+ *
+ * Returns: the buffer pointer on success
+ * NULL on error
+ */
+static void *qemu_io_alloc_from_file(BlockBackend *blk, size_t len,
+ const char *file_name)
+{
+ char *buf, *buf_origin;
+ FILE *f = fopen(file_name, "r");
+ int pattern_len;
+
+ if (!f) {
+ perror(file_name);
+ return NULL;
+ }
+
+ if (qemuio_misalign) {
+ len += MISALIGN_OFFSET;
+ }
+
+ buf_origin = buf = blk_blockalign(blk, len);
+
+ if (qemuio_misalign) {
+ buf_origin += MISALIGN_OFFSET;
+ buf += MISALIGN_OFFSET;
+ len -= MISALIGN_OFFSET;
+ }
+
+ pattern_len = fread(buf_origin, 1, len, f);
+
+ if (ferror(f)) {
+ perror(file_name);
+ goto error;
+ }
+
+ if (pattern_len == 0) {
+ fprintf(stderr, "%s: file is empty\n", file_name);
+ goto error;
+ }
+
+ fclose(f);
+ f = NULL;
+
+ if (len > pattern_len) {
+ len -= pattern_len;
+ buf += pattern_len;
+
+ while (len > 0) {
+ size_t len_to_copy = MIN(pattern_len, len);
+
+ memcpy(buf, buf_origin, len_to_copy);
+
+ len -= len_to_copy;
+ buf += len_to_copy;
+ }
+ }
+
+ return buf_origin;
+
+error:
+ qemu_io_free(buf_origin);
+ if (f) {
+ fclose(f);
+ }
+ return NULL;
+}
+