include/block/block-global-state.h

   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 the graph lock to be sure it
  35  * has unique access. The graph lock is needed together with BQL because of the
  36  * thread-safe I/O API that concurrently runs and accesses the graph without
  37  * the BQL.
  38  *
  39  * It is important to note that not all of these functions are
  40  * necessarily limited to running under the BQL, but they would
  41  * require additional auditing and many small thread-safety changes
  42  * to move them into the I/O API. Often it's not worth doing that
  43  * work since the APIs are only used with the BQL held at the
  44  * moment, so they have been placed in the GS API (for now).
  45  *
  46  * These functions can call any function from this and other categories
  47  * (I/O, "I/O or GS", Common), but must be invoked only by other GS APIs.
  48  *
  49  * All functions in this header must use the macro
  50  * GLOBAL_STATE_CODE();
  51  * to catch when they are accidentally called without the BQL.
  52  */
  53
  54 void bdrv_init(void);
  55 BlockDriver *bdrv_find_protocol(const char *filename,
  56                                 bool allow_protocol_prefix,
  57                                 Error **errp);
  58 BlockDriver *bdrv_find_format(const char *format_name);
  59
  60 int coroutine_fn GRAPH_UNLOCKED
  61 bdrv_co_create(BlockDriver *drv, const char *filename, QemuOpts *opts,
  62                Error **errp);
  63
  64 int co_wrapper bdrv_create(BlockDriver *drv, const char *filename,
  65                            QemuOpts *opts, Error **errp);
  66
  67 int coroutine_fn GRAPH_UNLOCKED
  68 bdrv_co_create_file(const char *filename, QemuOpts *opts, Error **errp);
  69
  70 BlockDriverState *bdrv_new(void);
  71 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
  72                 Error **errp);
  73
  74 int GRAPH_WRLOCK
  75 bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, Error **errp);
  76
  77 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
  78                           Error **errp);
  79 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
  80                                    int flags, Error **errp);
  81 int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
  82
  83 BdrvChild * no_coroutine_fn
  84 bdrv_open_child(const char *filename, QDict *options, const char *bdref_key,
  85                 BlockDriverState *parent, const BdrvChildClass *child_class,
  86                 BdrvChildRole child_role, bool allow_none, Error **errp);
  87
  88 BdrvChild * coroutine_fn no_co_wrapper
  89 bdrv_co_open_child(const char *filename, QDict *options, const char *bdref_key,
  90                 BlockDriverState *parent, const BdrvChildClass *child_class,
  91                 BdrvChildRole child_role, bool allow_none, Error **errp);
  92
  93 int bdrv_open_file_child(const char *filename,
  94                          QDict *options, const char *bdref_key,
  95                          BlockDriverState *parent, Error **errp);
  96
  97 BlockDriverState * no_coroutine_fn
  98 bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
  99
 100 BlockDriverState * coroutine_fn no_co_wrapper
 101 bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp);
 102
 103 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
 104                         Error **errp);
 105 int GRAPH_WRLOCK
 106 bdrv_set_backing_hd_drained(BlockDriverState *bs, BlockDriverState *backing_hd,
 107                             Error **errp);
 108
 109 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 110                            const char *bdref_key, Error **errp);
 111
 112 BlockDriverState * no_coroutine_fn
 113 bdrv_open(const char *filename, const char *reference, QDict *options,
 114           int flags, Error **errp);
 115
 116 BlockDriverState * coroutine_fn no_co_wrapper
 117 bdrv_co_open(const char *filename, const char *reference,
 118              QDict *options, int flags, Error **errp);
 119
 120 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
 121                                             const char *node_name,
 122                                             QDict *options, int flags,
 123                                             Error **errp);
 124 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
 125                                        int flags, Error **errp);
 126 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 127                                     BlockDriverState *bs, QDict *options,
 128                                     bool keep_old_opts);
 129 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
 130 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 131 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
 132                 Error **errp);
 133 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
 134                               Error **errp);
 135 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 136                                           const char *backing_file);
 137 void GRAPH_RDLOCK bdrv_refresh_filename(BlockDriverState *bs);
 138
 139 void GRAPH_RDLOCK
 140 bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
 141
 142 int bdrv_commit(BlockDriverState *bs);
 143 int GRAPH_RDLOCK bdrv_make_empty(BdrvChild *c, Error **errp);
 144
 145 void bdrv_register(BlockDriver *bdrv);
 146 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 147                            const char *backing_file_str);
 148
 149 BlockDriverState * GRAPH_RDLOCK
 150 bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs);
 151
 152 BlockDriverState * GRAPH_RDLOCK bdrv_find_base(BlockDriverState *bs);
 153
 154 int GRAPH_RDLOCK
 155 bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
 156                           Error **errp);
 157 void GRAPH_RDLOCK
 158 bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
 159
 160 /*
 161  * The units of offset and total_work_size may be chosen arbitrarily by the
 162  * block driver; total_work_size may change during the course of the amendment
 163  * operation
 164  */
 165 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 166                                       int64_t total_work_size, void *opaque);
 167 int GRAPH_RDLOCK
 168 bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 169                    BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 170                    bool force, Error **errp);
 171
 172 /* check if a named node can be replaced when doing drive-mirror */
 173 BlockDriverState * GRAPH_RDLOCK
 174 check_to_replace_node(BlockDriverState *parent_bs, const char *node_name,
 175                       Error **errp);
 176
 177 int no_coroutine_fn GRAPH_RDLOCK
 178 bdrv_activate(BlockDriverState *bs, Error **errp);
 179
 180 int coroutine_fn no_co_wrapper_bdrv_rdlock
 181 bdrv_co_activate(BlockDriverState *bs, Error **errp);
 182
 183 void bdrv_activate_all(Error **errp);
 184 int bdrv_inactivate_all(void);
 185
 186 int bdrv_flush_all(void);
 187 void bdrv_close_all(void);
 188 void bdrv_drain_all_begin(void);
 189 void bdrv_drain_all_begin_nopoll(void);
 190 void bdrv_drain_all_end(void);
 191 void bdrv_drain_all(void);
 192
 193 void bdrv_aio_cancel(BlockAIOCB *acb);
 194
 195 int bdrv_has_zero_init_1(BlockDriverState *bs);
 196 int coroutine_mixed_fn GRAPH_RDLOCK bdrv_has_zero_init(BlockDriverState *bs);
 197 BlockDriverState *bdrv_find_node(const char *node_name);
 198 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
 199 XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp);
 200 BlockDriverState *bdrv_lookup_bs(const char *device,
 201                                  const char *node_name,
 202                                  Error **errp);
 203 bool GRAPH_RDLOCK
 204 bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 205
 206 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 207 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 208
 209 typedef struct BdrvNextIterator {
 210     enum {
 211         BDRV_NEXT_BACKEND_ROOTS,
 212         BDRV_NEXT_MONITOR_OWNED,
 213     } phase;
 214     BlockBackend *blk;
 215     BlockDriverState *bs;
 216 } BdrvNextIterator;
 217
 218 BlockDriverState * GRAPH_RDLOCK bdrv_first(BdrvNextIterator *it);
 219 BlockDriverState * GRAPH_RDLOCK bdrv_next(BdrvNextIterator *it);
 220 void bdrv_next_cleanup(BdrvNextIterator *it);
 221
 222 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 223 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 224                          void *opaque, bool read_only);
 225
 226 char * GRAPH_RDLOCK
 227 bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
 228
 229 char * GRAPH_RDLOCK bdrv_dirname(BlockDriverState *bs, Error **errp);
 230
 231 void bdrv_img_create(const char *filename, const char *fmt,
 232                      const char *base_filename, const char *base_fmt,
 233                      char *options, uint64_t img_size, int flags,
 234                      bool quiet, Error **errp);
 235
 236 void bdrv_ref(BlockDriverState *bs);
 237 void no_coroutine_fn bdrv_unref(BlockDriverState *bs);
 238 void coroutine_fn no_co_wrapper bdrv_co_unref(BlockDriverState *bs);
 239 void GRAPH_WRLOCK bdrv_schedule_unref(BlockDriverState *bs);
 240
 241 void GRAPH_WRLOCK
 242 bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 243
 244 void coroutine_fn no_co_wrapper_bdrv_wrlock
 245 bdrv_co_unref_child(BlockDriverState *parent, BdrvChild *child);
 246
 247 BdrvChild * GRAPH_WRLOCK
 248 bdrv_attach_child(BlockDriverState *parent_bs,
 249                   BlockDriverState *child_bs,
 250                   const char *child_name,
 251                   const BdrvChildClass *child_class,
 252                   BdrvChildRole child_role,
 253                   Error **errp);
 254
 255 bool GRAPH_RDLOCK
 256 bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 257
 258 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 259 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 260 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 261 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 262 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 263
 264 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 265                            const char *tag);
 266 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 267 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 268 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 269
 270 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
 271                                    GHashTable *visited, Transaction *tran,
 272                                    Error **errp);
 273 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
 274                                 BdrvChild *ignore_child, Error **errp);
 275
 276 int GRAPH_RDLOCK bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 277 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 278
 279 void GRAPH_WRLOCK
 280 bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp);
 281
 282 void GRAPH_WRLOCK
 283 bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 284
 285 /**
 286  *
 287  * bdrv_register_buf/bdrv_unregister_buf:
 288  *
 289  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 290  * interested to know the memory areas that would later be used for I/O, so
 291  * that they can prepare IOMMU mapping etc., to get better performance.
 292  *
 293  * Buffers must not overlap and they must be unregistered with the same <host,
 294  * size> values that they were registered with.
 295  *
 296  * Returns: true on success, false on failure
 297  */
 298 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
 299                        Error **errp);
 300 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
 301
 302 void bdrv_cancel_in_flight(BlockDriverState *bs);
 303
 304 #endif /* BLOCK_GLOBAL_STATE_H */