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 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 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
  75                       Error **errp);
  76 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
  77                           Error **errp);
  78 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
  79                                    int flags, Error **errp);
  80 int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
  81
  82 BdrvChild * no_coroutine_fn
  83 bdrv_open_child(const char *filename, QDict *options, const char *bdref_key,
  84                 BlockDriverState *parent, const BdrvChildClass *child_class,
  85                 BdrvChildRole child_role, bool allow_none, Error **errp);
  86
  87 BdrvChild * coroutine_fn no_co_wrapper
  88 bdrv_co_open_child(const char *filename, QDict *options, const char *bdref_key,
  89                 BlockDriverState *parent, const BdrvChildClass *child_class,
  90                 BdrvChildRole child_role, bool allow_none, Error **errp);
  91
  92 int bdrv_open_file_child(const char *filename,
  93                          QDict *options, const char *bdref_key,
  94                          BlockDriverState *parent, Error **errp);
  95
  96 BlockDriverState * no_coroutine_fn
  97 bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
  98
  99 BlockDriverState * coroutine_fn no_co_wrapper
 100 bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp);
 101
 102 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
 103                         Error **errp);
 104 int bdrv_set_backing_hd_drained(BlockDriverState *bs,
 105                                 BlockDriverState *backing_hd,
 106                                 Error **errp);
 107 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
 108                            const char *bdref_key, Error **errp);
 109
 110 BlockDriverState * no_coroutine_fn
 111 bdrv_open(const char *filename, const char *reference, QDict *options,
 112           int flags, Error **errp);
 113
 114 BlockDriverState * coroutine_fn no_co_wrapper
 115 bdrv_co_open(const char *filename, const char *reference,
 116              QDict *options, int flags, Error **errp);
 117
 118 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
 119                                             const char *node_name,
 120                                             QDict *options, int flags,
 121                                             Error **errp);
 122 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
 123                                        int flags, Error **errp);
 124 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
 125                                     BlockDriverState *bs, QDict *options,
 126                                     bool keep_old_opts);
 127 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
 128 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 129 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
 130                 Error **errp);
 131 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
 132                               Error **errp);
 133 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 134                                           const char *backing_file);
 135 void GRAPH_RDLOCK bdrv_refresh_filename(BlockDriverState *bs);
 136
 137 void GRAPH_RDLOCK
 138 bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
 139
 140 int bdrv_commit(BlockDriverState *bs);
 141 int GRAPH_RDLOCK bdrv_make_empty(BdrvChild *c, Error **errp);
 142 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
 143                              const char *backing_fmt, bool warn);
 144 void bdrv_register(BlockDriver *bdrv);
 145 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 146                            const char *backing_file_str);
 147 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 148                                     BlockDriverState *bs);
 149 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 150 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
 151                                   Error **errp);
 152 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
 153                               Error **errp);
 154 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
 155
 156 /*
 157  * The units of offset and total_work_size may be chosen arbitrarily by the
 158  * block driver; total_work_size may change during the course of the amendment
 159  * operation
 160  */
 161 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 162                                       int64_t total_work_size, void *opaque);
 163 int GRAPH_RDLOCK
 164 bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 165                    BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 166                    bool force, Error **errp);
 167
 168 /* check if a named node can be replaced when doing drive-mirror */
 169 BlockDriverState * GRAPH_RDLOCK
 170 check_to_replace_node(BlockDriverState *parent_bs, const char *node_name,
 171                       Error **errp);
 172
 173 int no_coroutine_fn GRAPH_RDLOCK
 174 bdrv_activate(BlockDriverState *bs, Error **errp);
 175
 176 int coroutine_fn no_co_wrapper_bdrv_rdlock
 177 bdrv_co_activate(BlockDriverState *bs, Error **errp);
 178
 179 void bdrv_activate_all(Error **errp);
 180 int bdrv_inactivate_all(void);
 181
 182 int bdrv_flush_all(void);
 183 void bdrv_close_all(void);
 184 void bdrv_drain_all_begin(void);
 185 void bdrv_drain_all_begin_nopoll(void);
 186 void bdrv_drain_all_end(void);
 187 void bdrv_drain_all(void);
 188
 189 void bdrv_aio_cancel(BlockAIOCB *acb);
 190
 191 int bdrv_has_zero_init_1(BlockDriverState *bs);
 192 int bdrv_has_zero_init(BlockDriverState *bs);
 193 BlockDriverState *bdrv_find_node(const char *node_name);
 194 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
 195 XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp);
 196 BlockDriverState *bdrv_lookup_bs(const char *device,
 197                                  const char *node_name,
 198                                  Error **errp);
 199 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 200 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 201 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 202
 203 typedef struct BdrvNextIterator {
 204     enum {
 205         BDRV_NEXT_BACKEND_ROOTS,
 206         BDRV_NEXT_MONITOR_OWNED,
 207     } phase;
 208     BlockBackend *blk;
 209     BlockDriverState *bs;
 210 } BdrvNextIterator;
 211
 212 BlockDriverState * GRAPH_RDLOCK bdrv_first(BdrvNextIterator *it);
 213 BlockDriverState * GRAPH_RDLOCK bdrv_next(BdrvNextIterator *it);
 214 void bdrv_next_cleanup(BdrvNextIterator *it);
 215
 216 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 217 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 218                          void *opaque, bool read_only);
 219
 220 char * GRAPH_RDLOCK
 221 bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
 222
 223 char * GRAPH_RDLOCK bdrv_dirname(BlockDriverState *bs, Error **errp);
 224
 225 void bdrv_img_create(const char *filename, const char *fmt,
 226                      const char *base_filename, const char *base_fmt,
 227                      char *options, uint64_t img_size, int flags,
 228                      bool quiet, Error **errp);
 229
 230 void bdrv_ref(BlockDriverState *bs);
 231 void no_coroutine_fn bdrv_unref(BlockDriverState *bs);
 232 void coroutine_fn no_co_wrapper bdrv_co_unref(BlockDriverState *bs);
 233 void GRAPH_WRLOCK bdrv_schedule_unref(BlockDriverState *bs);
 234
 235 void GRAPH_WRLOCK
 236 bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 237
 238 void coroutine_fn no_co_wrapper_bdrv_wrlock
 239 bdrv_co_unref_child(BlockDriverState *parent, BdrvChild *child);
 240
 241 BdrvChild * GRAPH_WRLOCK
 242 bdrv_attach_child(BlockDriverState *parent_bs,
 243                   BlockDriverState *child_bs,
 244                   const char *child_name,
 245                   const BdrvChildClass *child_class,
 246                   BdrvChildRole child_role,
 247                   Error **errp);
 248
 249 bool GRAPH_RDLOCK
 250 bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 251
 252 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 253 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 254 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 255 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 256 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 257
 258 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 259                            const char *tag);
 260 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 261 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 262 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 263
 264 /**
 265  * Locks the AioContext of @bs if it's not the current AioContext. This avoids
 266  * double locking which could lead to deadlocks: This is a coroutine_fn, so we
 267  * know we already own the lock of the current AioContext.
 268  *
 269  * May only be called in the main thread.
 270  */
 271 void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
 272
 273 /**
 274  * Unlocks the AioContext of @bs if it's not the current AioContext.
 275  */
 276 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
 277
 278 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
 279                                    GHashTable *visited, Transaction *tran,
 280                                    Error **errp);
 281 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
 282                                 BdrvChild *ignore_child, Error **errp);
 283
 284 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 285 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 286
 287 void GRAPH_WRLOCK
 288 bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp);
 289
 290 void GRAPH_WRLOCK
 291 bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 292
 293 /**
 294  *
 295  * bdrv_register_buf/bdrv_unregister_buf:
 296  *
 297  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 298  * interested to know the memory areas that would later be used for I/O, so
 299  * that they can prepare IOMMU mapping etc., to get better performance.
 300  *
 301  * Buffers must not overlap and they must be unregistered with the same <host,
 302  * size> values that they were registered with.
 303  *
 304  * Returns: true on success, false on failure
 305  */
 306 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
 307                        Error **errp);
 308 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
 309
 310 void bdrv_cancel_in_flight(BlockDriverState *bs);
 311
 312 #endif /* BLOCK_GLOBAL_STATE_H */