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