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_RDLOCK
  62 bdrv_co_create(BlockDriver *drv, const char *filename, QemuOpts *opts,
  63                Error **errp);
  64
  65 int co_wrapper_bdrv_rdlock bdrv_create(BlockDriver *drv, const char *filename,
  66                                        QemuOpts *opts, Error **errp);
  67
  68 int coroutine_fn GRAPH_RDLOCK
  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 bdrv_refresh_filename(BlockDriverState *bs);
 136 void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
 137 int bdrv_commit(BlockDriverState *bs);
 138 int bdrv_make_empty(BdrvChild *c, Error **errp);
 139 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
 140                              const char *backing_fmt, bool warn);
 141 void bdrv_register(BlockDriver *bdrv);
 142 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 143                            const char *backing_file_str);
 144 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 145                                     BlockDriverState *bs);
 146 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 147 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
 148                                   Error **errp);
 149 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
 150                               Error **errp);
 151 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
 152
 153 /*
 154  * The units of offset and total_work_size may be chosen arbitrarily by the
 155  * block driver; total_work_size may change during the course of the amendment
 156  * operation
 157  */
 158 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 159                                       int64_t total_work_size, void *opaque);
 160 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 161                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 162                        bool force,
 163                        Error **errp);
 164
 165 /* check if a named node can be replaced when doing drive-mirror */
 166 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 167                                         const char *node_name, Error **errp);
 168
 169 int bdrv_activate(BlockDriverState *bs, Error **errp);
 170 void bdrv_activate_all(Error **errp);
 171 int bdrv_inactivate_all(void);
 172
 173 int bdrv_flush_all(void);
 174 void bdrv_close_all(void);
 175 void bdrv_drain_all_begin(void);
 176 void bdrv_drain_all_begin_nopoll(void);
 177 void bdrv_drain_all_end(void);
 178 void bdrv_drain_all(void);
 179
 180 int bdrv_has_zero_init_1(BlockDriverState *bs);
 181 int bdrv_has_zero_init(BlockDriverState *bs);
 182 BlockDriverState *bdrv_find_node(const char *node_name);
 183 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
 184 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
 185 BlockDriverState *bdrv_lookup_bs(const char *device,
 186                                  const char *node_name,
 187                                  Error **errp);
 188 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 189 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 190 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 191
 192 typedef struct BdrvNextIterator {
 193     enum {
 194         BDRV_NEXT_BACKEND_ROOTS,
 195         BDRV_NEXT_MONITOR_OWNED,
 196     } phase;
 197     BlockBackend *blk;
 198     BlockDriverState *bs;
 199 } BdrvNextIterator;
 200
 201 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 202 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 203 void bdrv_next_cleanup(BdrvNextIterator *it);
 204
 205 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 206 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 207                          void *opaque, bool read_only);
 208 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
 209 char *bdrv_dirname(BlockDriverState *bs, Error **errp);
 210
 211 void bdrv_img_create(const char *filename, const char *fmt,
 212                      const char *base_filename, const char *base_fmt,
 213                      char *options, uint64_t img_size, int flags,
 214                      bool quiet, Error **errp);
 215
 216 void bdrv_ref(BlockDriverState *bs);
 217 void bdrv_unref(BlockDriverState *bs);
 218 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 219 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 220                              BlockDriverState *child_bs,
 221                              const char *child_name,
 222                              const BdrvChildClass *child_class,
 223                              BdrvChildRole child_role,
 224                              Error **errp);
 225
 226 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 227 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 228 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 229 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 230 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 231 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 232
 233 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 234                            const char *tag);
 235 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 236 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 237 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 238
 239 /**
 240  * Locks the AioContext of @bs if it's not the current AioContext. This avoids
 241  * double locking which could lead to deadlocks: This is a coroutine_fn, so we
 242  * know we already own the lock of the current AioContext.
 243  *
 244  * May only be called in the main thread.
 245  */
 246 void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
 247
 248 /**
 249  * Unlocks the AioContext of @bs if it's not the current AioContext.
 250  */
 251 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
 252
 253 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
 254                                    GHashTable *visited, Transaction *tran,
 255                                    Error **errp);
 256 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
 257                                 BdrvChild *ignore_child, Error **errp);
 258
 259 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 260 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 261
 262 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 263                     Error **errp);
 264 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 265
 266 /**
 267  *
 268  * bdrv_register_buf/bdrv_unregister_buf:
 269  *
 270  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 271  * interested to know the memory areas that would later be used for I/O, so
 272  * that they can prepare IOMMU mapping etc., to get better performance.
 273  *
 274  * Buffers must not overlap and they must be unregistered with the same <host,
 275  * size> values that they were registered with.
 276  *
 277  * Returns: true on success, false on failure
 278  */
 279 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
 280                        Error **errp);
 281 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
 282
 283 void bdrv_cancel_in_flight(BlockDriverState *bs);
 284
 285 #endif /* BLOCK_GLOBAL_STATE_H */