include/block/block_int-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_INT_GLOBAL_STATE_H
  25 #define BLOCK_INT_GLOBAL_STATE_H
  26
  27 #include "block_int-common.h"
  28
  29 /*
  30  * Global state (GS) API. These functions run under the BQL.
  31  *
  32  * See include/block/block-global-state.h for more information about
  33  * the GS API.
  34  */
  35
  36 /**
  37  * stream_start:
  38  * @job_id: The id of the newly-created job, or %NULL to use the
  39  * device name of @bs.
  40  * @bs: Block device to operate on.
  41  * @base: Block device that will become the new base, or %NULL to
  42  * flatten the whole backing file chain onto @bs.
  43  * @backing_file_str: The file name that will be written to @bs as the
  44  * the new backing file if the job completes. Ignored if @base is %NULL.
  45  * @creation_flags: Flags that control the behavior of the Job lifetime.
  46  *                  See @BlockJobCreateFlags
  47  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
  48  * @on_error: The action to take upon error.
  49  * @filter_node_name: The node name that should be assigned to the filter
  50  *                    driver that the stream job inserts into the graph above
  51  *                    @bs. NULL means that a node name should be autogenerated.
  52  * @errp: Error object.
  53  *
  54  * Start a streaming operation on @bs.  Clusters that are unallocated
  55  * in @bs, but allocated in any image between @base and @bs (both
  56  * exclusive) will be written to @bs.  At the end of a successful
  57  * streaming job, the backing file of @bs will be changed to
  58  * @backing_file_str in the written image and to @base in the live
  59  * BlockDriverState.
  60  */
  61 void stream_start(const char *job_id, BlockDriverState *bs,
  62                   BlockDriverState *base, const char *backing_file_str,
  63                   BlockDriverState *bottom,
  64                   int creation_flags, int64_t speed,
  65                   BlockdevOnError on_error,
  66                   const char *filter_node_name,
  67                   Error **errp);
  68
  69 /**
  70  * commit_start:
  71  * @job_id: The id of the newly-created job, or %NULL to use the
  72  * device name of @bs.
  73  * @bs: Active block device.
  74  * @top: Top block device to be committed.
  75  * @base: Block device that will be written into, and become the new top.
  76  * @creation_flags: Flags that control the behavior of the Job lifetime.
  77  *                  See @BlockJobCreateFlags
  78  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
  79  * @on_error: The action to take upon error.
  80  * @backing_file_str: String to use as the backing file in @top's overlay
  81  * @filter_node_name: The node name that should be assigned to the filter
  82  * driver that the commit job inserts into the graph above @top. NULL means
  83  * that a node name should be autogenerated.
  84  * @errp: Error object.
  85  *
  86  */
  87 void commit_start(const char *job_id, BlockDriverState *bs,
  88                   BlockDriverState *base, BlockDriverState *top,
  89                   int creation_flags, int64_t speed,
  90                   BlockdevOnError on_error, const char *backing_file_str,
  91                   const char *filter_node_name, Error **errp);
  92 /**
  93  * commit_active_start:
  94  * @job_id: The id of the newly-created job, or %NULL to use the
  95  * device name of @bs.
  96  * @bs: Active block device to be committed.
  97  * @base: Block device that will be written into, and become the new top.
  98  * @creation_flags: Flags that control the behavior of the Job lifetime.
  99  *                  See @BlockJobCreateFlags
 100  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 101  * @on_error: The action to take upon error.
 102  * @filter_node_name: The node name that should be assigned to the filter
 103  * driver that the commit job inserts into the graph above @bs. NULL means that
 104  * a node name should be autogenerated.
 105  * @cb: Completion function for the job.
 106  * @opaque: Opaque pointer value passed to @cb.
 107  * @auto_complete: Auto complete the job.
 108  * @errp: Error object.
 109  *
 110  */
 111 BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
 112                               BlockDriverState *base, int creation_flags,
 113                               int64_t speed, BlockdevOnError on_error,
 114                               const char *filter_node_name,
 115                               BlockCompletionFunc *cb, void *opaque,
 116                               bool auto_complete, Error **errp);
 117 /*
 118  * mirror_start:
 119  * @job_id: The id of the newly-created job, or %NULL to use the
 120  * device name of @bs.
 121  * @bs: Block device to operate on.
 122  * @target: Block device to write to.
 123  * @replaces: Block graph node name to replace once the mirror is done. Can
 124  *            only be used when full mirroring is selected.
 125  * @creation_flags: Flags that control the behavior of the Job lifetime.
 126  *                  See @BlockJobCreateFlags
 127  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 128  * @granularity: The chosen granularity for the dirty bitmap.
 129  * @buf_size: The amount of data that can be in flight at one time.
 130  * @mode: Whether to collapse all images in the chain to the target.
 131  * @backing_mode: How to establish the target's backing chain after completion.
 132  * @zero_target: Whether the target should be explicitly zero-initialized
 133  * @on_source_error: The action to take upon error reading from the source.
 134  * @on_target_error: The action to take upon error writing to the target.
 135  * @unmap: Whether to unmap target where source sectors only contain zeroes.
 136  * @filter_node_name: The node name that should be assigned to the filter
 137  * driver that the mirror job inserts into the graph above @bs. NULL means that
 138  * a node name should be autogenerated.
 139  * @copy_mode: When to trigger writes to the target.
 140  * @errp: Error object.
 141  *
 142  * Start a mirroring operation on @bs.  Clusters that are allocated
 143  * in @bs will be written to @target until the job is cancelled or
 144  * manually completed.  At the end of a successful mirroring job,
 145  * @bs will be switched to read from @target.
 146  */
 147 void mirror_start(const char *job_id, BlockDriverState *bs,
 148                   BlockDriverState *target, const char *replaces,
 149                   int creation_flags, int64_t speed,
 150                   uint32_t granularity, int64_t buf_size,
 151                   MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
 152                   bool zero_target,
 153                   BlockdevOnError on_source_error,
 154                   BlockdevOnError on_target_error,
 155                   bool unmap, const char *filter_node_name,
 156                   MirrorCopyMode copy_mode, Error **errp);
 157
 158 /*
 159  * backup_job_create:
 160  * @job_id: The id of the newly-created job, or %NULL to use the
 161  * device name of @bs.
 162  * @bs: Block device to operate on.
 163  * @target: Block device to write to.
 164  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
 165  * @sync_mode: What parts of the disk image should be copied to the destination.
 166  * @sync_bitmap: The dirty bitmap if sync_mode is 'bitmap' or 'incremental'
 167  * @bitmap_mode: The bitmap synchronization policy to use.
 168  * @perf: Performance options. All actual fields assumed to be present,
 169  *        all ".has_*" fields are ignored.
 170  * @on_source_error: The action to take upon error reading from the source.
 171  * @on_target_error: The action to take upon error writing to the target.
 172  * @creation_flags: Flags that control the behavior of the Job lifetime.
 173  *                  See @BlockJobCreateFlags
 174  * @cb: Completion function for the job.
 175  * @opaque: Opaque pointer value passed to @cb.
 176  * @txn: Transaction that this job is part of (may be NULL).
 177  *
 178  * Create a backup operation on @bs.  Clusters in @bs are written to @target
 179  * until the job is cancelled or manually completed.
 180  */
 181 BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
 182                             BlockDriverState *target, int64_t speed,
 183                             MirrorSyncMode sync_mode,
 184                             BdrvDirtyBitmap *sync_bitmap,
 185                             BitmapSyncMode bitmap_mode,
 186                             bool compress,
 187                             const char *filter_node_name,
 188                             BackupPerf *perf,
 189                             BlockdevOnError on_source_error,
 190                             BlockdevOnError on_target_error,
 191                             int creation_flags,
 192                             BlockCompletionFunc *cb, void *opaque,
 193                             JobTxn *txn, Error **errp);
 194
 195 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
 196                                   const char *child_name,
 197                                   const BdrvChildClass *child_class,
 198                                   BdrvChildRole child_role,
 199                                   uint64_t perm, uint64_t shared_perm,
 200                                   void *opaque, Error **errp);
 201 void bdrv_root_unref_child(BdrvChild *child);
 202
 203 void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
 204                               uint64_t *shared_perm);
 205
 206 /**
 207  * Sets a BdrvChild's permissions.  Avoid if the parent is a BDS; use
 208  * bdrv_child_refresh_perms() instead and make the parent's
 209  * .bdrv_child_perm() implementation return the correct values.
 210  */
 211 int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
 212                             Error **errp);
 213
 214 /**
 215  * Calls bs->drv->bdrv_child_perm() and updates the child's permission
 216  * masks with the result.
 217  * Drivers should invoke this function whenever an event occurs that
 218  * makes their .bdrv_child_perm() implementation return different
 219  * values than before, but which will not result in the block layer
 220  * automatically refreshing the permissions.
 221  */
 222 int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp);
 223
 224 bool bdrv_recurse_can_replace(BlockDriverState *bs,
 225                               BlockDriverState *to_replace);
 226
 227 /*
 228  * Default implementation for BlockDriver.bdrv_child_perm() that can
 229  * be used by block filters and image formats, as long as they use the
 230  * child_of_bds child class and set an appropriate BdrvChildRole.
 231  */
 232 void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
 233                         BdrvChildRole role, BlockReopenQueue *reopen_queue,
 234                         uint64_t perm, uint64_t shared,
 235                         uint64_t *nperm, uint64_t *nshared);
 236
 237 void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
 238 bool blk_dev_has_removable_media(BlockBackend *blk);
 239 void blk_dev_eject_request(BlockBackend *blk, bool force);
 240 bool blk_dev_is_medium_locked(BlockBackend *blk);
 241
 242 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
 243
 244 void bdrv_set_monitor_owned(BlockDriverState *bs);
 245
 246 void blockdev_close_all_bdrv_states(void);
 247
 248 BlockDriverState *bds_tree_init(QDict *bs_opts, Error **errp);
 249
 250 /**
 251  * Simple implementation of bdrv_co_create_opts for protocol drivers
 252  * which only support creation via opening a file
 253  * (usually existing raw storage device)
 254  */
 255 int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
 256                                             const char *filename,
 257                                             QemuOpts *opts,
 258                                             Error **errp);
 259
 260 BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
 261                                            const char *name,
 262                                            BlockDriverState **pbs,
 263                                            Error **errp);
 264 BdrvDirtyBitmap *block_dirty_bitmap_merge(const char *node, const char *target,
 265                                           BlockDirtyBitmapOrStrList *bms,
 266                                           HBitmap **backup, Error **errp);
 267 BdrvDirtyBitmap *block_dirty_bitmap_remove(const char *node, const char *name,
 268                                            bool release,
 269                                            BlockDriverState **bitmap_bs,
 270                                            Error **errp);
 271
 272
 273 BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs);
 274
 275 /**
 276  * bdrv_add_aio_context_notifier:
 277  *
 278  * If a long-running job intends to be always run in the same AioContext as a
 279  * certain BDS, it may use this function to be notified of changes regarding the
 280  * association of the BDS to an AioContext.
 281  *
 282  * attached_aio_context() is called after the target BDS has been attached to a
 283  * new AioContext; detach_aio_context() is called before the target BDS is being
 284  * detached from its old AioContext.
 285  */
 286 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
 287         void (*attached_aio_context)(AioContext *new_context, void *opaque),
 288         void (*detach_aio_context)(void *opaque), void *opaque);
 289
 290 /**
 291  * bdrv_remove_aio_context_notifier:
 292  *
 293  * Unsubscribe of change notifications regarding the BDS's AioContext. The
 294  * parameters given here have to be the same as those given to
 295  * bdrv_add_aio_context_notifier().
 296  */
 297 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
 298                                       void (*aio_context_attached)(AioContext *,
 299                                                                    void *),
 300                                       void (*aio_context_detached)(void *),
 301                                       void *opaque);
 302
 303 /**
 304  * End all quiescent sections started by bdrv_drain_all_begin(). This is
 305  * needed when deleting a BDS before bdrv_drain_all_end() is called.
 306  *
 307  * NOTE: this is an internal helper for bdrv_close() *only*. No one else
 308  * should call it.
 309  */
 310 void bdrv_drain_all_end_quiesce(BlockDriverState *bs);
 311
 312 /**
 313  * Make sure that the function is running under both drain and BQL.
 314  * The latter protects from concurrent writings
 315  * from the GS API, while the former prevents concurrent reads
 316  * from I/O.
 317  */
 318 static inline void assert_bdrv_graph_writable(BlockDriverState *bs)
 319 {
 320     /*
 321      * TODO: this function is incomplete. Because the users of this
 322      * assert lack the necessary drains, check only for BQL.
 323      * Once the necessary drains are added,
 324      * assert also for qatomic_read(&bs->quiesce_counter) > 0
 325      */
 326     assert(qemu_in_main_thread());
 327 }
 328
 329 #endif /* BLOCK_INT_GLOBAL_STATE */