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 bdrv_co_create(BlockDriver *drv, const char *filename, 62 QemuOpts *opts, Error **errp); 63 int co_wrapper bdrv_create(BlockDriver *drv, const char *filename, 64 QemuOpts *opts, Error **errp); 65 66 int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts, 67 Error **errp); 68 69 BlockDriverState *bdrv_new(void); 70 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, 71 Error **errp); 72 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, 73 Error **errp); 74 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, 75 Error **errp); 76 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options, 77 int flags, Error **errp); 78 int bdrv_drop_filter(BlockDriverState *bs, Error **errp); 79 80 BdrvChild * no_coroutine_fn 81 bdrv_open_child(const char *filename, QDict *options, const char *bdref_key, 82 BlockDriverState *parent, const BdrvChildClass *child_class, 83 BdrvChildRole child_role, bool allow_none, Error **errp); 84 85 BdrvChild * coroutine_fn no_co_wrapper 86 bdrv_co_open_child(const char *filename, QDict *options, const char *bdref_key, 87 BlockDriverState *parent, const BdrvChildClass *child_class, 88 BdrvChildRole child_role, bool allow_none, Error **errp); 89 90 int bdrv_open_file_child(const char *filename, 91 QDict *options, const char *bdref_key, 92 BlockDriverState *parent, Error **errp); 93 94 BlockDriverState * no_coroutine_fn 95 bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp); 96 97 BlockDriverState * coroutine_fn no_co_wrapper 98 bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp); 99 100 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, 101 Error **errp); 102 int bdrv_set_backing_hd_drained(BlockDriverState *bs, 103 BlockDriverState *backing_hd, 104 Error **errp); 105 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, 106 const char *bdref_key, Error **errp); 107 108 BlockDriverState * no_coroutine_fn 109 bdrv_open(const char *filename, const char *reference, QDict *options, 110 int flags, Error **errp); 111 112 BlockDriverState * coroutine_fn no_co_wrapper 113 bdrv_co_open(const char *filename, const char *reference, 114 QDict *options, int flags, Error **errp); 115 116 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv, 117 const char *node_name, 118 QDict *options, int flags, 119 Error **errp); 120 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, 121 int flags, Error **errp); 122 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, 123 BlockDriverState *bs, QDict *options, 124 bool keep_old_opts); 125 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue); 126 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp); 127 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts, 128 Error **errp); 129 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, 130 Error **errp); 131 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, 132 const char *backing_file); 133 void bdrv_refresh_filename(BlockDriverState *bs); 134 void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp); 135 int bdrv_commit(BlockDriverState *bs); 136 int bdrv_make_empty(BdrvChild *c, Error **errp); 137 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, 138 const char *backing_fmt, bool warn); 139 void bdrv_register(BlockDriver *bdrv); 140 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, 141 const char *backing_file_str); 142 BlockDriverState *bdrv_find_overlay(BlockDriverState *active, 143 BlockDriverState *bs); 144 BlockDriverState *bdrv_find_base(BlockDriverState *bs); 145 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, 146 Error **errp); 147 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, 148 Error **errp); 149 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base); 150 151 /* 152 * The units of offset and total_work_size may be chosen arbitrarily by the 153 * block driver; total_work_size may change during the course of the amendment 154 * operation 155 */ 156 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset, 157 int64_t total_work_size, void *opaque); 158 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts, 159 BlockDriverAmendStatusCB *status_cb, void *cb_opaque, 160 bool force, 161 Error **errp); 162 163 /* check if a named node can be replaced when doing drive-mirror */ 164 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, 165 const char *node_name, Error **errp); 166 167 int bdrv_activate(BlockDriverState *bs, Error **errp); 168 void bdrv_activate_all(Error **errp); 169 int bdrv_inactivate_all(void); 170 171 int bdrv_flush_all(void); 172 void bdrv_close_all(void); 173 void bdrv_drain_all_begin(void); 174 void bdrv_drain_all_begin_nopoll(void); 175 void bdrv_drain_all_end(void); 176 void bdrv_drain_all(void); 177 178 int bdrv_has_zero_init_1(BlockDriverState *bs); 179 int bdrv_has_zero_init(BlockDriverState *bs); 180 BlockDriverState *bdrv_find_node(const char *node_name); 181 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp); 182 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp); 183 BlockDriverState *bdrv_lookup_bs(const char *device, 184 const char *node_name, 185 Error **errp); 186 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base); 187 BlockDriverState *bdrv_next_node(BlockDriverState *bs); 188 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs); 189 190 typedef struct BdrvNextIterator { 191 enum { 192 BDRV_NEXT_BACKEND_ROOTS, 193 BDRV_NEXT_MONITOR_OWNED, 194 } phase; 195 BlockBackend *blk; 196 BlockDriverState *bs; 197 } BdrvNextIterator; 198 199 BlockDriverState *bdrv_first(BdrvNextIterator *it); 200 BlockDriverState *bdrv_next(BdrvNextIterator *it); 201 void bdrv_next_cleanup(BdrvNextIterator *it); 202 203 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); 204 void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 205 void *opaque, bool read_only); 206 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); 207 char *bdrv_dirname(BlockDriverState *bs, Error **errp); 208 209 void bdrv_img_create(const char *filename, const char *fmt, 210 const char *base_filename, const char *base_fmt, 211 char *options, uint64_t img_size, int flags, 212 bool quiet, Error **errp); 213 214 void bdrv_ref(BlockDriverState *bs); 215 void bdrv_unref(BlockDriverState *bs); 216 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); 217 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, 218 BlockDriverState *child_bs, 219 const char *child_name, 220 const BdrvChildClass *child_class, 221 BdrvChildRole child_role, 222 Error **errp); 223 224 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); 225 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason); 226 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason); 227 void bdrv_op_block_all(BlockDriverState *bs, Error *reason); 228 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); 229 bool bdrv_op_blocker_is_empty(BlockDriverState *bs); 230 231 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, 232 const char *tag); 233 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); 234 int bdrv_debug_resume(BlockDriverState *bs, const char *tag); 235 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); 236 237 /** 238 * Locks the AioContext of @bs if it's not the current AioContext. This avoids 239 * double locking which could lead to deadlocks: This is a coroutine_fn, so we 240 * know we already own the lock of the current AioContext. 241 * 242 * May only be called in the main thread. 243 */ 244 void coroutine_fn bdrv_co_lock(BlockDriverState *bs); 245 246 /** 247 * Unlocks the AioContext of @bs if it's not the current AioContext. 248 */ 249 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs); 250 251 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx, 252 GHashTable *visited, Transaction *tran, 253 Error **errp); 254 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, 255 BdrvChild *ignore_child, Error **errp); 256 257 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz); 258 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo); 259 260 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, 261 Error **errp); 262 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); 263 264 /** 265 * 266 * bdrv_register_buf/bdrv_unregister_buf: 267 * 268 * Register/unregister a buffer for I/O. For example, VFIO drivers are 269 * interested to know the memory areas that would later be used for I/O, so 270 * that they can prepare IOMMU mapping etc., to get better performance. 271 * 272 * Buffers must not overlap and they must be unregistered with the same <host, 273 * size> values that they were registered with. 274 * 275 * Returns: true on success, false on failure 276 */ 277 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size, 278 Error **errp); 279 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size); 280 281 void bdrv_cancel_in_flight(BlockDriverState *bs); 282 283 #endif /* BLOCK_GLOBAL_STATE_H */ 284