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-common.h"
  28
  29 /*
  30  * Global state (GS) API. These functions run under the BQL.
  31  *
  32  * If a function modifies the graph, it also uses drain and/or
  33  * aio_context_acquire/release to be sure it has unique access.
  34  * aio_context locking is needed together with BQL because of
  35  * the thread-safe I/O API that concurrently runs and accesses
  36  * the graph without the BQL.
  37  *
  38  * It is important to note that not all of these functions are
  39  * necessarily limited to running under the BQL, but they would
  40  * require additional auditing and many small thread-safety changes
  41  * to move them into the I/O API. Often it's not worth doing that
  42  * work since the APIs are only used with the BQL held at the
  43  * moment, so they have been placed in the GS API (for now).
  44  *
  45  * These functions can call any function from this and other categories
  46  * (I/O, "I/O or GS", Common), but must be invoked only by other GS APIs.
  47  *
  48  * All functions in this header must use the macro
  49  * GLOBAL_STATE_CODE();
  50  * to catch when they are accidentally called without the BQL.
  51  */
  52
  53 void bdrv_init(void);
  54 BlockDriver *bdrv_find_protocol(const char *filename,
  55                                 bool allow_protocol_prefix,
  56                                 Error **errp);
  57 BlockDriver *bdrv_find_format(const char *format_name);
  58 int bdrv_create(BlockDriver *drv, const char* filename,
  59                 QemuOpts *opts, Error **errp);
  60 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
  61
  62 BlockDriverState *bdrv_new(void);
  63 int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
  64                 Error **errp);
  65 int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
  66                       Error **errp);
  67 int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
  68                           Error **errp);
  69 BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
  70                                    int flags, Error **errp);
  71 int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
  72
  73 BdrvChild *bdrv_open_child(const char *filename,
  74                            QDict *options, const char *bdref_key,
  75                            BlockDriverState *parent,
  76                            const BdrvChildClass *child_class,
  77                            BdrvChildRole child_role,
  78                            bool allow_none, Error **errp);
  79 int bdrv_open_file_child(const char *filename,
  80                          QDict *options, const char *bdref_key,
  81                          BlockDriverState *parent, Error **errp);
  82 BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
  83 int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
  84                         Error **errp);
  85 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
  86                            const char *bdref_key, Error **errp);
  87 BlockDriverState *bdrv_open(const char *filename, const char *reference,
  88                             QDict *options, int flags, Error **errp);
  89 BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
  90                                             const char *node_name,
  91                                             QDict *options, int flags,
  92                                             Error **errp);
  93 BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
  94                                        int flags, Error **errp);
  95 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
  96                                     BlockDriverState *bs, QDict *options,
  97                                     bool keep_old_opts);
  98 void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
  99 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
 100 int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
 101                 Error **errp);
 102 int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
 103                               Error **errp);
 104 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
 105                                           const char *backing_file);
 106 void bdrv_refresh_filename(BlockDriverState *bs);
 107 void bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
 108 int bdrv_commit(BlockDriverState *bs);
 109 int bdrv_make_empty(BdrvChild *c, Error **errp);
 110 int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
 111                              const char *backing_fmt, bool warn);
 112 void bdrv_register(BlockDriver *bdrv);
 113 int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
 114                            const char *backing_file_str);
 115 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
 116                                     BlockDriverState *bs);
 117 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
 118 bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
 119                                   Error **errp);
 120 int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
 121                               Error **errp);
 122 void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
 123
 124 /*
 125  * The units of offset and total_work_size may be chosen arbitrarily by the
 126  * block driver; total_work_size may change during the course of the amendment
 127  * operation
 128  */
 129 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
 130                                       int64_t total_work_size, void *opaque);
 131 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
 132                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
 133                        bool force,
 134                        Error **errp);
 135
 136 /* check if a named node can be replaced when doing drive-mirror */
 137 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
 138                                         const char *node_name, Error **errp);
 139
 140 int bdrv_activate(BlockDriverState *bs, Error **errp);
 141 void bdrv_activate_all(Error **errp);
 142 int bdrv_inactivate_all(void);
 143
 144 int bdrv_flush_all(void);
 145 void bdrv_close_all(void);
 146 void bdrv_drain_all_begin(void);
 147 void bdrv_drain_all_end(void);
 148 void bdrv_drain_all(void);
 149
 150 int bdrv_has_zero_init_1(BlockDriverState *bs);
 151 int bdrv_has_zero_init(BlockDriverState *bs);
 152 BlockDriverState *bdrv_find_node(const char *node_name);
 153 BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
 154 XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp);
 155 BlockDriverState *bdrv_lookup_bs(const char *device,
 156                                  const char *node_name,
 157                                  Error **errp);
 158 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
 159 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
 160 BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
 161
 162 typedef struct BdrvNextIterator {
 163     enum {
 164         BDRV_NEXT_BACKEND_ROOTS,
 165         BDRV_NEXT_MONITOR_OWNED,
 166     } phase;
 167     BlockBackend *blk;
 168     BlockDriverState *bs;
 169 } BdrvNextIterator;
 170
 171 BlockDriverState *bdrv_first(BdrvNextIterator *it);
 172 BlockDriverState *bdrv_next(BdrvNextIterator *it);
 173 void bdrv_next_cleanup(BdrvNextIterator *it);
 174
 175 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
 176 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
 177                          void *opaque, bool read_only);
 178 char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
 179 char *bdrv_dirname(BlockDriverState *bs, Error **errp);
 180
 181 void bdrv_img_create(const char *filename, const char *fmt,
 182                      const char *base_filename, const char *base_fmt,
 183                      char *options, uint64_t img_size, int flags,
 184                      bool quiet, Error **errp);
 185
 186 void bdrv_ref(BlockDriverState *bs);
 187 void bdrv_unref(BlockDriverState *bs);
 188 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
 189 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
 190                              BlockDriverState *child_bs,
 191                              const char *child_name,
 192                              const BdrvChildClass *child_class,
 193                              BdrvChildRole child_role,
 194                              Error **errp);
 195
 196 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
 197 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
 198 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
 199 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
 200 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
 201 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
 202
 203 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
 204                            const char *tag);
 205 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
 206 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
 207 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
 208
 209 /**
 210  * Locks the AioContext of @bs if it's not the current AioContext. This avoids
 211  * double locking which could lead to deadlocks: This is a coroutine_fn, so we
 212  * know we already own the lock of the current AioContext.
 213  *
 214  * May only be called in the main thread.
 215  */
 216 void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
 217
 218 /**
 219  * Unlocks the AioContext of @bs if it's not the current AioContext.
 220  */
 221 void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
 222
 223 AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c);
 224 bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
 225                                    GHashTable *visited, Transaction *tran,
 226                                    Error **errp);
 227 int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
 228                                 BdrvChild *ignore_child, Error **errp);
 229
 230 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
 231 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
 232
 233 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
 234                     Error **errp);
 235 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
 236
 237 /**
 238  *
 239  * bdrv_register_buf/bdrv_unregister_buf:
 240  *
 241  * Register/unregister a buffer for I/O. For example, VFIO drivers are
 242  * interested to know the memory areas that would later be used for I/O, so
 243  * that they can prepare IOMMU mapping etc., to get better performance.
 244  *
 245  * Buffers must not overlap and they must be unregistered with the same <host,
 246  * size> values that they were registered with.
 247  *
 248  * Returns: true on success, false on failure
 249  */
 250 bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
 251                        Error **errp);
 252 void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
 253
 254 void bdrv_cancel_in_flight(BlockDriverState *bs);
 255
 256 #endif /* BLOCK_GLOBAL_STATE_H */