static void v9fs_read(void *opaque) { int32_t fid; uint64_t off; ssize_t err = 0; int32_t count = 0; size_t offset = 7; uint32_t max_count; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &max_count); trace_v9fs_read(pdu->tag, pdu->id, fid, off, max_count); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } if (fidp->fid_type == P9_FID_DIR) { if (off == 0) { v9fs_co_rewinddir(pdu, fidp); } count = v9fs_do_readdir_with_stat(pdu, fidp, max_count); if (count < 0) { err = count; goto out; } err = offset; err += pdu_marshal(pdu, offset, "d", count); err += count; } else if (fidp->fid_type == P9_FID_FILE) { QEMUIOVector qiov_full; QEMUIOVector qiov; int32_t len; v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset + 4, max_count, false); qemu_iovec_init(&qiov, qiov_full.niov); do { qemu_iovec_reset(&qiov); qemu_iovec_copy(&qiov, &qiov_full, count, qiov_full.size - count); if (0) { print_sg(qiov.iov, qiov.niov); } /* Loop in case of EINTR */ do { len = v9fs_co_preadv(pdu, fidp, qiov.iov, qiov.niov, off); if (len >= 0) { off += len; count += len; } } while (len == -EINTR && !pdu->cancelled); if (len < 0) { /* IO error return the error */ err = len; goto out; } } while (count < max_count && len > 0); err = offset; err += pdu_marshal(pdu, offset, "d", count); err += count; qemu_iovec_destroy(&qiov); qemu_iovec_destroy(&qiov_full); } else if (fidp->fid_type == P9_FID_XATTR) { err = v9fs_xattr_read(s, pdu, fidp, off, max_count); } else { err = -EINVAL; } trace_v9fs_read_return(pdu->tag, pdu->id, count, err); out: put_fid(pdu, fidp); out_nofid: complete_pdu(s, pdu, err); }