include/sysemu/block-backend-io.h

   1 /*
   2  * QEMU Block backends
   3  *
   4  * Copyright (C) 2014-2016 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *  Markus Armbruster <armbru@redhat.com>,
   8  *
   9  * This work is licensed under the terms of the GNU LGPL, version 2.1
  10  * or later.  See the COPYING.LIB file in the top-level directory.
  11  */
  12
  13 #ifndef BLOCK_BACKEND_IO_H
  14 #define BLOCK_BACKEND_IO_H
  15
  16 #include "block-backend-common.h"
  17
  18 /*
  19  * I/O API functions. These functions are thread-safe.
  20  *
  21  * See include/block/block-io.h for more information about
  22  * the I/O API.
  23  */
  24
  25 const char *blk_name(const BlockBackend *blk);
  26
  27 BlockDriverState *blk_bs(BlockBackend *blk);
  28
  29 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
  30 void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
  31 void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
  32 bool blk_iostatus_is_enabled(const BlockBackend *blk);
  33
  34 char *blk_get_attached_dev_id(BlockBackend *blk);
  35
  36 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
  37                                   int64_t bytes, BdrvRequestFlags flags,
  38                                   BlockCompletionFunc *cb, void *opaque);
  39
  40 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
  41                            QEMUIOVector *qiov, BdrvRequestFlags flags,
  42                            BlockCompletionFunc *cb, void *opaque);
  43 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
  44                             QEMUIOVector *qiov, BdrvRequestFlags flags,
  45                             BlockCompletionFunc *cb, void *opaque);
  46 BlockAIOCB *blk_aio_flush(BlockBackend *blk,
  47                           BlockCompletionFunc *cb, void *opaque);
  48 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes,
  49                              BlockCompletionFunc *cb, void *opaque);
  50 void blk_aio_cancel_async(BlockAIOCB *acb);
  51 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
  52                           BlockCompletionFunc *cb, void *opaque);
  53
  54 void blk_inc_in_flight(BlockBackend *blk);
  55 void blk_dec_in_flight(BlockBackend *blk);
  56 bool blk_is_inserted(BlockBackend *blk);
  57 bool blk_is_available(BlockBackend *blk);
  58 void blk_lock_medium(BlockBackend *blk, bool locked);
  59 void blk_eject(BlockBackend *blk, bool eject_flag);
  60 int64_t blk_getlength(BlockBackend *blk);
  61 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
  62 int64_t blk_nb_sectors(BlockBackend *blk);
  63 void *blk_try_blockalign(BlockBackend *blk, size_t size);
  64 void *blk_blockalign(BlockBackend *blk, size_t size);
  65 bool blk_is_writable(BlockBackend *blk);
  66 bool blk_enable_write_cache(BlockBackend *blk);
  67 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
  68 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
  69                                       int error);
  70 void blk_error_action(BlockBackend *blk, BlockErrorAction action,
  71                       bool is_read, int error);
  72 void blk_iostatus_set_err(BlockBackend *blk, int error);
  73 int blk_get_max_iov(BlockBackend *blk);
  74 int blk_get_max_hw_iov(BlockBackend *blk);
  75
  76 void blk_io_plug(BlockBackend *blk);
  77 void blk_io_unplug(BlockBackend *blk);
  78 AioContext *blk_get_aio_context(BlockBackend *blk);
  79 BlockAcctStats *blk_get_stats(BlockBackend *blk);
  80 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
  81                   BlockCompletionFunc *cb, void *opaque);
  82 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
  83                                   BlockCompletionFunc *cb,
  84                                   void *opaque, int ret);
  85
  86 uint32_t blk_get_request_alignment(BlockBackend *blk);
  87 uint32_t blk_get_max_transfer(BlockBackend *blk);
  88 uint64_t blk_get_max_hw_transfer(BlockBackend *blk);
  89
  90 int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
  91                                    BlockBackend *blk_out, int64_t off_out,
  92                                    int64_t bytes, BdrvRequestFlags read_flags,
  93                                    BdrvRequestFlags write_flags);
  94
  95
  96 /*
  97  * "I/O or GS" API functions. These functions can run without
  98  * the BQL, but only in one specific iothread/main loop.
  99  *
 100  * See include/block/block-io.h for more information about
 101  * the "I/O or GS" API.
 102  */
 103
 104 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
 105 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
 106                BdrvRequestFlags flags);
 107 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 108                                int64_t bytes, QEMUIOVector *qiov,
 109                                BdrvRequestFlags flags);
 110 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
 111                                      int64_t bytes,
 112                                      QEMUIOVector *qiov, size_t qiov_offset,
 113                                      BdrvRequestFlags flags);
 114 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
 115                                 int64_t bytes, QEMUIOVector *qiov,
 116                                 BdrvRequestFlags flags);
 117
 118 static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
 119                                             int64_t bytes, void *buf,
 120                                             BdrvRequestFlags flags)
 121 {
 122     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 123     IO_OR_GS_CODE();
 124
 125     assert(bytes <= SIZE_MAX);
 126
 127     return blk_co_preadv(blk, offset, bytes, &qiov, flags);
 128 }
 129
 130 static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
 131                                              int64_t bytes, void *buf,
 132                                              BdrvRequestFlags flags)
 133 {
 134     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
 135     IO_OR_GS_CODE();
 136
 137     assert(bytes <= SIZE_MAX);
 138
 139     return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
 140 }
 141
 142 int coroutine_fn blk_co_pdiscard(BlockBackend *blk, int64_t offset,
 143                                  int64_t bytes);
 144
 145 int coroutine_fn blk_co_flush(BlockBackend *blk);
 146 int blk_flush(BlockBackend *blk);
 147
 148 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 149
 150 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
 151                           int64_t bytes);
 152 int blk_pdiscard(BlockBackend *blk, int64_t offset, int64_t bytes);
 153 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 154                       int64_t bytes, BdrvRequestFlags flags);
 155 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
 156                                       int64_t bytes, BdrvRequestFlags flags);
 157 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
 158                  PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
 159
 160 #endif /* BLOCK_BACKEND_IO_H */