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 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 */