1 /* 2 * QEMU System Emulator block driver 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #ifndef BLOCK_GLOBAL_STATE_H 25 #define BLOCK_GLOBAL_STATE_H 26 27 #include "block/block-common.h" 28 #include "qemu/coroutine.h" 29 #include "qemu/transactions.h" 30 31 /* 32 * Global state (GS) API. These functions run under the BQL. 33 * 34 * If a function modifies the graph, it also uses drain and/or 35 * aio_context_acquire/release to be sure it has unique access. 36 * aio_context locking is needed together with BQL because of 37 * the thread-safe I/O API that concurrently runs and accesses 38 * the graph without the BQL. 39 * 40 * It is important to note that not all of these functions are 41 * necessarily limited to running under the BQL, but they would 42 * require additional auditing and many small thread-safety changes 43 * to move them into the I/O API. Often it's not worth doing that 44 * work since the APIs are only used with the BQL held at the 45 * moment, so they have been placed in the GS API (for now). 46 * 47 * These functions can call any function from this and other categories 48 * (I/O, "I/O or GS", Common), but must be invoked only by other GS APIs. 49 * 50 * All functions in this header must use the macro 51 * GLOBAL_STATE_CODE(); 52 * to catch when they are accidentally called without the BQL. 53 */ 54 55 void bdrv_init(void); 56 BlockDriver *bdrv_find_protocol(const char *filename, 57 bool allow_protocol_prefix, 58 Error **errp); 59 BlockDriver *bdrv_find_format(const char *format_name); 60 61 int coroutine_fn GRAPH_UNLOCKED 62 bdrv_co_create(BlockDriver *drv, const char *filename, QemuOpts *opts, 63 Error **errp); 64 65 int co_wrapper bdrv_create(BlockDriver *drv, const char *filename, 66 QemuOpts *opts, Error **errp); 67 68 int coroutine_fn GRAPH_UNLOCKED 69 bdrv_co_create_file(const char *filename, QemuOpts *opts, Error **errp); 70 71 BlockDriverState *bdrv_new(void); 72 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, 73 Error **errp); 74 75 int GRAPH_WRLOCK 76 bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, Error **errp); 77 78 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, 79 Error **errp); 80 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options, 81 int flags, Error **errp); 82 int bdrv_drop_filter(BlockDriverState *bs, Error **errp); 83 84 BdrvChild * no_coroutine_fn 85 bdrv_open_child(const char *filename, QDict *options, const char *bdref_key, 86 BlockDriverState *parent, const BdrvChildClass *child_class, 87 BdrvChildRole child_role, bool allow_none, Error **errp); 88 89 BdrvChild * coroutine_fn no_co_wrapper 90 bdrv_co_open_child(const char *filename, QDict *options, const char *bdref_key, 91 BlockDriverState *parent, const BdrvChildClass *child_class, 92 BdrvChildRole child_role, bool allow_none, Error **errp); 93 94 int bdrv_open_file_child(const char *filename, 95 QDict *options, const char *bdref_key, 96 BlockDriverState *parent, Error **errp); 97 98 BlockDriverState * no_coroutine_fn 99 bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp); 100 101 BlockDriverState * coroutine_fn no_co_wrapper 102 bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp); 103 104 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, 105 Error **errp); 106 int GRAPH_WRLOCK 107 bdrv_set_backing_hd_drained(BlockDriverState *bs, BlockDriverState *backing_hd, 108 Error **errp); 109 110 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, 111 const char *bdref_key, Error **errp); 112 113 BlockDriverState * no_coroutine_fn 114 bdrv_open(const char *filename, const char *reference, QDict *options, 115 int flags, Error **errp); 116 117 BlockDriverState * coroutine_fn no_co_wrapper 118 bdrv_co_open(const char *filename, const char *reference, 119 QDict *options, int flags, Error **errp); 120 121 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv, 122 const char *node_name, 123 QDict *options, int flags, 124 Error **errp); 125 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, 126 int flags, Error **errp); 127 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, 128 BlockDriverState *bs, QDict *options, 129 bool keep_old_opts); 130 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue); 131 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp); 132 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts, 133 Error **errp); 134 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, 135 Error **errp); 136 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, 137 const char *backing_file); 138 void GRAPH_RDLOCK bdrv_refresh_filename(BlockDriverState *bs); 139 140 void GRAPH_RDLOCK 141 bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp); 142 143 int bdrv_commit(BlockDriverState *bs); 144 int GRAPH_RDLOCK bdrv_make_empty(BdrvChild *c, Error **errp); 145 146 void bdrv_register(BlockDriver *bdrv); 147 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, 148 const char *backing_file_str); 149 150 BlockDriverState * GRAPH_RDLOCK 151 bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs); 152 153 BlockDriverState * GRAPH_RDLOCK bdrv_find_base(BlockDriverState *bs); 154 155 int GRAPH_RDLOCK 156 bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, 157 Error **errp); 158 void GRAPH_RDLOCK 159 bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base); 160 161 /* 162 * The units of offset and total_work_size may be chosen arbitrarily by the 163 * block driver; total_work_size may change during the course of the amendment 164 * operation 165 */ 166 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset, 167 int64_t total_work_size, void *opaque); 168 int GRAPH_RDLOCK 169 bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts, 170 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 171 bool force, Error **errp); 172 173 /* check if a named node can be replaced when doing drive-mirror */ 174 BlockDriverState * GRAPH_RDLOCK 175 check_to_replace_node(BlockDriverState *parent_bs, const char *node_name, 176 Error **errp); 177 178 int no_coroutine_fn GRAPH_RDLOCK 179 bdrv_activate(BlockDriverState *bs, Error **errp); 180 181 int coroutine_fn no_co_wrapper_bdrv_rdlock 182 bdrv_co_activate(BlockDriverState *bs, Error **errp); 183 184 void bdrv_activate_all(Error **errp); 185 int bdrv_inactivate_all(void); 186 187 int bdrv_flush_all(void); 188 void bdrv_close_all(void); 189 void bdrv_drain_all_begin(void); 190 void bdrv_drain_all_begin_nopoll(void); 191 void bdrv_drain_all_end(void); 192 void bdrv_drain_all(void); 193 194 void bdrv_aio_cancel(BlockAIOCB *acb); 195 196 int bdrv_has_zero_init_1(BlockDriverState *bs); 197 int coroutine_mixed_fn GRAPH_RDLOCK bdrv_has_zero_init(BlockDriverState *bs); 198 BlockDriverState *bdrv_find_node(const char *node_name); 199 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp); 200 XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp); 201 BlockDriverState *bdrv_lookup_bs(const char *device, 202 const char *node_name, 203 Error **errp); 204 bool GRAPH_RDLOCK 205 bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); 206 207 BlockDriverState *bdrv_next_node(BlockDriverState *bs); 208 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs); 209 210 typedef struct BdrvNextIterator { 211 enum { 212 BDRV_NEXT_BACKEND_ROOTS, 213 BDRV_NEXT_MONITOR_OWNED, 214 } phase; 215 BlockBackend *blk; 216 BlockDriverState *bs; 217 } BdrvNextIterator; 218 219 BlockDriverState * GRAPH_RDLOCK bdrv_first(BdrvNextIterator *it); 220 BlockDriverState * GRAPH_RDLOCK bdrv_next(BdrvNextIterator *it); 221 void bdrv_next_cleanup(BdrvNextIterator *it); 222 223 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); 224 void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 225 void *opaque, bool read_only); 226 227 char * GRAPH_RDLOCK 228 bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); 229 230 char * GRAPH_RDLOCK bdrv_dirname(BlockDriverState *bs, Error **errp); 231 232 void bdrv_img_create(const char *filename, const char *fmt, 233 const char *base_filename, const char *base_fmt, 234 char *options, uint64_t img_size, int flags, 235 bool quiet, Error **errp); 236 237 void bdrv_ref(BlockDriverState *bs); 238 void no_coroutine_fn bdrv_unref(BlockDriverState *bs); 239 void coroutine_fn no_co_wrapper bdrv_co_unref(BlockDriverState *bs); 240 void GRAPH_WRLOCK bdrv_schedule_unref(BlockDriverState *bs); 241 242 void GRAPH_WRLOCK 243 bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); 244 245 void coroutine_fn no_co_wrapper_bdrv_wrlock 246 bdrv_co_unref_child(BlockDriverState *parent, BdrvChild *child); 247 248 BdrvChild * GRAPH_WRLOCK 249 bdrv_attach_child(BlockDriverState *parent_bs, 250 BlockDriverState *child_bs, 251 const char *child_name, 252 const BdrvChildClass *child_class, 253 BdrvChildRole child_role, 254 Error **errp); 255 256 bool GRAPH_RDLOCK 257 bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); 258 259 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); 260 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason); 261 void bdrv_op_block_all(BlockDriverState *bs, Error *reason); 262 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); 263 bool bdrv_op_blocker_is_empty(BlockDriverState *bs); 264 265 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, 266 const char *tag); 267 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); 268 int bdrv_debug_resume(BlockDriverState *bs, const char *tag); 269 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); 270 271 /** 272 * Locks the AioContext of @bs if it's not the current AioContext. This avoids 273 * double locking which could lead to deadlocks: This is a coroutine_fn, so we 274 * know we already own the lock of the current AioContext. 275 * 276 * May only be called in the main thread. 277 */ 278 void coroutine_fn bdrv_co_lock(BlockDriverState *bs); 279 280 /** 281 * Unlocks the AioContext of @bs if it's not the current AioContext. 282 */ 283 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs); 284 285 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx, 286 GHashTable *visited, Transaction *tran, 287 Error **errp); 288 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, 289 BdrvChild *ignore_child, Error **errp); 290 291 int GRAPH_RDLOCK bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); 292 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); 293 294 void GRAPH_WRLOCK 295 bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp); 296 297 void GRAPH_WRLOCK 298 bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); 299 300 /** 301 * 302 * bdrv_register_buf/bdrv_unregister_buf: 303 * 304 * Register/unregister a buffer for I/O. For example, VFIO drivers are 305 * interested to know the memory areas that would later be used for I/O, so 306 * that they can prepare IOMMU mapping etc., to get better performance. 307 * 308 * Buffers must not overlap and they must be unregistered with the same <host, 309 * size> values that they were registered with. 310 * 311 * Returns: true on success, false on failure 312 */ 313 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size, 314 Error **errp); 315 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size); 316 317 void bdrv_cancel_in_flight(BlockDriverState *bs); 318 319 #endif /* BLOCK_GLOBAL_STATE_H */ 320