/* * QEMU System Emulator block write threshold notification * * Copyright Red Hat, Inc. 2014 * * Authors: * Francesco Romani <fromani@redhat.com> * * This work is licensed under the terms of the GNU LGPL, version 2 or later. * See the COPYING.LIB file in the top-level directory. */ #ifndef BLOCK_WRITE_THRESHOLD_H #define BLOCK_WRITE_THRESHOLD_H #include "block/block_int.h" /* * bdrv_write_threshold_set: * * Set the write threshold for block devices, in bytes. * Notify when a write exceeds the threshold, meaning the device * is becoming full, so it can be transparently resized. * To be used with thin-provisioned block devices. * * Use threshold_bytes == 0 to disable. */ void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes); /* * bdrv_write_threshold_get * * Get the configured write threshold, in bytes. * Zero means no threshold configured. */ uint64_t bdrv_write_threshold_get(const BlockDriverState *bs); /* * bdrv_write_threshold_is_set * * Tell if a write threshold is set for a given BDS. */ bool bdrv_write_threshold_is_set(const BlockDriverState *bs); /* * bdrv_write_threshold_exceeded * * Return the extent of a write request that exceeded the threshold, * or zero if the request is below the threshold. * Return zero also if the threshold was not set. * * NOTE: here we assume the following holds for each request this code * deals with: * * assert((req->offset + req->bytes) <= UINT64_MAX) * * Please not there is *not* an actual C assert(). */ uint64_t bdrv_write_threshold_exceeded(const BlockDriverState *bs, const BdrvTrackedRequest *req); #endif