include/block/write-threshold.h

   1 /*
   2  * QEMU System Emulator block write threshold notification
   3  *
   4  * Copyright Red Hat, Inc. 2014
   5  *
   6  * Authors:
   7  *  Francesco Romani <fromani@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  10  * See the COPYING.LIB file in the top-level directory.
  11  */
  12
  13 #ifndef BLOCK_WRITE_THRESHOLD_H
  14 #define BLOCK_WRITE_THRESHOLD_H
  15
  16 /*
  17  * bdrv_write_threshold_set:
  18  *
  19  * Set the write threshold for block devices, in bytes.
  20  * Notify when a write exceeds the threshold, meaning the device
  21  * is becoming full, so it can be transparently resized.
  22  * To be used with thin-provisioned block devices.
  23  *
  24  * Use threshold_bytes == 0 to disable.
  25  */
  26 void bdrv_write_threshold_set(BlockDriverState *bs, uint64_t threshold_bytes);
  27
  28 /*
  29  * bdrv_write_threshold_get
  30  *
  31  * Get the configured write threshold, in bytes.
  32  * Zero means no threshold configured.
  33  */
  34 uint64_t bdrv_write_threshold_get(const BlockDriverState *bs);
  35
  36 /*
  37  * bdrv_write_threshold_check_write
  38  *
  39  * Check whether the specified request exceeds the write threshold.
  40  * If so, send a corresponding event and disable write threshold checking.
  41  */
  42 void bdrv_write_threshold_check_write(BlockDriverState *bs, int64_t offset,
  43                                       int64_t bytes);
  44
  45 #endif