include/block/block-copy.h

   1 /*
   2  * block_copy API
   3  *
   4  * Copyright (C) 2013 Proxmox Server Solutions
   5  * Copyright (c) 2019 Virtuozzo International GmbH.
   6  *
   7  * Authors:
   8  *  Dietmar Maurer (dietmar@proxmox.com)
   9  *  Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  */
  14
  15 #ifndef BLOCK_COPY_H
  16 #define BLOCK_COPY_H
  17
  18 #include "block/block.h"
  19
  20 typedef struct BlockCopyInFlightReq {
  21     int64_t start_byte;
  22     int64_t end_byte;
  23     QLIST_ENTRY(BlockCopyInFlightReq) list;
  24     CoQueue wait_queue; /* coroutines blocked on this request */
  25 } BlockCopyInFlightReq;
  26
  27 typedef void (*ProgressBytesCallbackFunc)(int64_t bytes, void *opaque);
  28 typedef void (*ProgressResetCallbackFunc)(void *opaque);
  29 typedef struct BlockCopyState {
  30     /*
  31      * BdrvChild objects are not owned or managed by block-copy. They are
  32      * provided by block-copy user and user is responsible for appropriate
  33      * permissions on these children.
  34      */
  35     BdrvChild *source;
  36     BdrvChild *target;
  37     BdrvDirtyBitmap *copy_bitmap;
  38     int64_t cluster_size;
  39     bool use_copy_range;
  40     int64_t copy_range_size;
  41     uint64_t len;
  42     QLIST_HEAD(, BlockCopyInFlightReq) inflight_reqs;
  43
  44     BdrvRequestFlags write_flags;
  45
  46     /*
  47      * skip_unallocated:
  48      *
  49      * Used by sync=top jobs, which first scan the source node for unallocated
  50      * areas and clear them in the copy_bitmap.  During this process, the bitmap
  51      * is thus not fully initialized: It may still have bits set for areas that
  52      * are unallocated and should actually not be copied.
  53      *
  54      * This is indicated by skip_unallocated.
  55      *
  56      * In this case, block_copy() will query the source’s allocation status,
  57      * skip unallocated regions, clear them in the copy_bitmap, and invoke
  58      * block_copy_reset_unallocated() every time it does.
  59      */
  60     bool skip_unallocated;
  61
  62     /* progress_bytes_callback: called when some copying progress is done. */
  63     ProgressBytesCallbackFunc progress_bytes_callback;
  64
  65     /*
  66      * progress_reset_callback: called when some bytes reset from copy_bitmap
  67      * (see @skip_unallocated above). The callee is assumed to recalculate how
  68      * many bytes remain based on the dirty bit count of copy_bitmap.
  69      */
  70     ProgressResetCallbackFunc progress_reset_callback;
  71     void *progress_opaque;
  72 } BlockCopyState;
  73
  74 BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
  75                                      int64_t cluster_size,
  76                                      BdrvRequestFlags write_flags,
  77                                      Error **errp);
  78
  79 void block_copy_set_callbacks(
  80         BlockCopyState *s,
  81         ProgressBytesCallbackFunc progress_bytes_callback,
  82         ProgressResetCallbackFunc progress_reset_callback,
  83         void *progress_opaque);
  84
  85 void block_copy_state_free(BlockCopyState *s);
  86
  87 int64_t block_copy_reset_unallocated(BlockCopyState *s,
  88                                      int64_t offset, int64_t *count);
  89
  90 int coroutine_fn block_copy(BlockCopyState *s, int64_t start, uint64_t bytes,
  91                             bool *error_is_read);
  92
  93 #endif /* BLOCK_COPY_H */