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 */ 161