| /* |
| * QEMU System Emulator block driver |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| #ifndef BLOCK_IO_H |
| #define BLOCK_IO_H |
| |
| #include "block-common.h" |
| |
| /* |
| * I/O API functions. These functions are thread-safe, and therefore |
| * can run in any thread as long as the thread has called |
| * aio_context_acquire/release(). |
| * |
| * These functions can only call functions from I/O and Common categories, |
| * but can be invoked by GS, "I/O or GS" and I/O APIs. |
| * |
| * All functions in this category must use the macro |
| * IO_CODE(); |
| * to catch when they are accidentally called by the wrong API. |
| */ |
| |
| int generated_co_wrapper bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, |
| int64_t bytes, |
| BdrvRequestFlags flags); |
| int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); |
| int generated_co_wrapper bdrv_pread(BdrvChild *child, int64_t offset, |
| int64_t bytes, void *buf, |
| BdrvRequestFlags flags); |
| int generated_co_wrapper bdrv_pwrite(BdrvChild *child, int64_t offset, |
| int64_t bytes, const void *buf, |
| BdrvRequestFlags flags); |
| int generated_co_wrapper bdrv_pwrite_sync(BdrvChild *child, int64_t offset, |
| int64_t bytes, const void *buf, |
| BdrvRequestFlags flags); |
| int coroutine_fn bdrv_co_pwrite_sync(BdrvChild *child, int64_t offset, |
| int64_t bytes, const void *buf, |
| BdrvRequestFlags flags); |
| /* |
| * Efficiently zero a region of the disk image. Note that this is a regular |
| * I/O request like read or write and should have a reasonable size. This |
| * function is not suitable for zeroing the entire image in a single request |
| * because it may allocate memory for the entire region. |
| */ |
| int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, |
| int64_t bytes, BdrvRequestFlags flags); |
| |
| int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact, |
| PreallocMode prealloc, BdrvRequestFlags flags, |
| Error **errp); |
| |
| int64_t bdrv_nb_sectors(BlockDriverState *bs); |
| int64_t bdrv_getlength(BlockDriverState *bs); |
| int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); |
| BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, |
| BlockDriverState *in_bs, Error **errp); |
| void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); |
| int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp); |
| void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs); |
| |
| |
| /* async block I/O */ |
| void bdrv_aio_cancel(BlockAIOCB *acb); |
| void bdrv_aio_cancel_async(BlockAIOCB *acb); |
| |
| /* sg packet commands */ |
| int coroutine_fn bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf); |
| |
| /* Ensure contents are flushed to disk. */ |
| int coroutine_fn bdrv_co_flush(BlockDriverState *bs); |
| |
| int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset, |
| int64_t bytes); |
| bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); |
| int bdrv_block_status(BlockDriverState *bs, int64_t offset, |
| int64_t bytes, int64_t *pnum, int64_t *map, |
| BlockDriverState **file); |
| int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, |
| int64_t offset, int64_t bytes, int64_t *pnum, |
| int64_t *map, BlockDriverState **file); |
| int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| int64_t *pnum); |
| int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, |
| bool include_base, int64_t offset, int64_t bytes, |
| int64_t *pnum); |
| int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, |
| int64_t bytes); |
| |
| int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, |
| bool ignore_allow_rdw, Error **errp); |
| int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, |
| Error **errp); |
| bool bdrv_is_read_only(BlockDriverState *bs); |
| bool bdrv_is_writable(BlockDriverState *bs); |
| bool bdrv_is_sg(BlockDriverState *bs); |
| int bdrv_get_flags(BlockDriverState *bs); |
| bool bdrv_is_inserted(BlockDriverState *bs); |
| void bdrv_lock_medium(BlockDriverState *bs, bool locked); |
| void bdrv_eject(BlockDriverState *bs, bool eject_flag); |
| const char *bdrv_get_format_name(BlockDriverState *bs); |
| |
| bool bdrv_supports_compressed_writes(BlockDriverState *bs); |
| const char *bdrv_get_node_name(const BlockDriverState *bs); |
| const char *bdrv_get_device_name(const BlockDriverState *bs); |
| const char *bdrv_get_device_or_node_name(const BlockDriverState *bs); |
| int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi); |
| ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, |
| Error **errp); |
| BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs); |
| void bdrv_round_to_clusters(BlockDriverState *bs, |
| int64_t offset, int64_t bytes, |
| int64_t *cluster_offset, |
| int64_t *cluster_bytes); |
| |
| void bdrv_get_backing_filename(BlockDriverState *bs, |
| char *filename, int filename_size); |
| |
| int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
| int64_t pos, int size); |
| |
| int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
| int64_t pos, int size); |
| |
| /* |
| * Returns the alignment in bytes that is required so that no bounce buffer |
| * is required throughout the stack |
| */ |
| size_t bdrv_min_mem_align(BlockDriverState *bs); |
| /* Returns optimal alignment in bytes for bounce buffer */ |
| size_t bdrv_opt_mem_align(BlockDriverState *bs); |
| void *qemu_blockalign(BlockDriverState *bs, size_t size); |
| void *qemu_blockalign0(BlockDriverState *bs, size_t size); |
| void *qemu_try_blockalign(BlockDriverState *bs, size_t size); |
| void *qemu_try_blockalign0(BlockDriverState *bs, size_t size); |
| |
| void bdrv_enable_copy_on_read(BlockDriverState *bs); |
| void bdrv_disable_copy_on_read(BlockDriverState *bs); |
| |
| void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event); |
| |
| #define BLKDBG_EVENT(child, evt) \ |
| do { \ |
| if (child) { \ |
| bdrv_debug_event(child->bs, evt); \ |
| } \ |
| } while (0) |
| |
| /** |
| * bdrv_get_aio_context: |
| * |
| * Returns: the currently bound #AioContext |
| */ |
| AioContext *bdrv_get_aio_context(BlockDriverState *bs); |
| |
| /** |
| * Move the current coroutine to the AioContext of @bs and return the old |
| * AioContext of the coroutine. Increase bs->in_flight so that draining @bs |
| * will wait for the operation to proceed until the corresponding |
| * bdrv_co_leave(). |
| * |
| * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as |
| * this will deadlock. |
| */ |
| AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); |
| |
| /** |
| * Ends a section started by bdrv_co_enter(). Move the current coroutine back |
| * to old_ctx and decrease bs->in_flight again. |
| */ |
| void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); |
| |
| /** |
| * Transfer control to @co in the aio context of @bs |
| */ |
| void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co); |
| |
| AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c); |
| |
| void bdrv_io_plug(BlockDriverState *bs); |
| void bdrv_io_unplug(BlockDriverState *bs); |
| |
| bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, |
| uint32_t granularity, Error **errp); |
| |
| /** |
| * |
| * bdrv_co_copy_range: |
| * |
| * Do offloaded copy between two children. If the operation is not implemented |
| * by the driver, or if the backend storage doesn't support it, a negative |
| * error code will be returned. |
| * |
| * Note: block layer doesn't emulate or fallback to a bounce buffer approach |
| * because usually the caller shouldn't attempt offloaded copy any more (e.g. |
| * calling copy_file_range(2)) after the first error, thus it should fall back |
| * to a read+write path in the caller level. |
| * |
| * @src: Source child to copy data from |
| * @src_offset: offset in @src image to read data |
| * @dst: Destination child to copy data to |
| * @dst_offset: offset in @dst image to write data |
| * @bytes: number of bytes to copy |
| * @flags: request flags. Supported flags: |
| * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero |
| * write on @dst as if bdrv_co_pwrite_zeroes is |
| * called. Used to simplify caller code, or |
| * during BlockDriver.bdrv_co_copy_range_from() |
| * recursion. |
| * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping |
| * requests currently in flight. |
| * |
| * Returns: 0 if succeeded; negative error code if failed. |
| **/ |
| int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, |
| BdrvChild *dst, int64_t dst_offset, |
| int64_t bytes, BdrvRequestFlags read_flags, |
| BdrvRequestFlags write_flags); |
| |
| /** |
| * bdrv_drained_end_no_poll: |
| * |
| * Same as bdrv_drained_end(), but do not poll for the subgraph to |
| * actually become unquiesced. Therefore, no graph changes will occur |
| * with this function. |
| * |
| * *drained_end_counter is incremented for every background operation |
| * that is scheduled, and will be decremented for every operation once |
| * it settles. The caller must poll until it reaches 0. The counter |
| * should be accessed using atomic operations only. |
| */ |
| void bdrv_drained_end_no_poll(BlockDriverState *bs, int *drained_end_counter); |
| |
| |
| /* |
| * "I/O or GS" API functions. These functions can run without |
| * the BQL, but only in one specific iothread/main loop. |
| * |
| * More specifically, these functions use BDRV_POLL_WHILE(bs), which |
| * requires the caller to be either in the main thread and hold |
| * the BlockdriverState (bs) AioContext lock, or directly in the |
| * home thread that runs the bs AioContext. Calling them from |
| * another thread in another AioContext would cause deadlocks. |
| * |
| * Therefore, these functions are not proper I/O, because they |
| * can't run in *any* iothreads, but only in a specific one. |
| * |
| * These functions can call any function from I/O, Common and this |
| * categories, but must be invoked only by other "I/O or GS" and GS APIs. |
| * |
| * All functions in this category must use the macro |
| * IO_OR_GS_CODE(); |
| * to catch when they are accidentally called by the wrong API. |
| */ |
| |
| #define BDRV_POLL_WHILE(bs, cond) ({ \ |
| BlockDriverState *bs_ = (bs); \ |
| IO_OR_GS_CODE(); \ |
| AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \ |
| cond); }) |
| |
| void bdrv_drain(BlockDriverState *bs); |
| |
| int generated_co_wrapper |
| bdrv_truncate(BdrvChild *child, int64_t offset, bool exact, |
| PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); |
| |
| int generated_co_wrapper bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, |
| BdrvCheckMode fix); |
| |
| /* Invalidate any cached metadata used by image formats */ |
| int generated_co_wrapper bdrv_invalidate_cache(BlockDriverState *bs, |
| Error **errp); |
| int generated_co_wrapper bdrv_flush(BlockDriverState *bs); |
| int generated_co_wrapper bdrv_pdiscard(BdrvChild *child, int64_t offset, |
| int64_t bytes); |
| int generated_co_wrapper |
| bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); |
| int generated_co_wrapper |
| bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); |
| |
| /** |
| * bdrv_parent_drained_begin_single: |
| * |
| * Begin a quiesced section for the parent of @c. If @poll is true, wait for |
| * any pending activity to cease. |
| */ |
| void bdrv_parent_drained_begin_single(BdrvChild *c, bool poll); |
| |
| /** |
| * bdrv_parent_drained_end_single: |
| * |
| * End a quiesced section for the parent of @c. |
| * |
| * This polls @bs's AioContext until all scheduled sub-drained_ends |
| * have settled, which may result in graph changes. |
| */ |
| void bdrv_parent_drained_end_single(BdrvChild *c); |
| |
| /** |
| * bdrv_drain_poll: |
| * |
| * Poll for pending requests in @bs, its parents (except for @ignore_parent), |
| * and if @recursive is true its children as well (used for subtree drain). |
| * |
| * If @ignore_bds_parents is true, parents that are BlockDriverStates must |
| * ignore the drain request because they will be drained separately (used for |
| * drain_all). |
| * |
| * This is part of bdrv_drained_begin. |
| */ |
| bool bdrv_drain_poll(BlockDriverState *bs, bool recursive, |
| BdrvChild *ignore_parent, bool ignore_bds_parents); |
| |
| /** |
| * bdrv_drained_begin: |
| * |
| * Begin a quiesced section for exclusive access to the BDS, by disabling |
| * external request sources including NBD server, block jobs, and device model. |
| * |
| * This function can be recursive. |
| */ |
| void bdrv_drained_begin(BlockDriverState *bs); |
| |
| /** |
| * bdrv_do_drained_begin_quiesce: |
| * |
| * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already |
| * running requests to complete. |
| */ |
| void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, |
| BdrvChild *parent, bool ignore_bds_parents); |
| |
| /** |
| * Like bdrv_drained_begin, but recursively begins a quiesced section for |
| * exclusive access to all child nodes as well. |
| */ |
| void bdrv_subtree_drained_begin(BlockDriverState *bs); |
| |
| /** |
| * bdrv_drained_end: |
| * |
| * End a quiescent section started by bdrv_drained_begin(). |
| * |
| * This polls @bs's AioContext until all scheduled sub-drained_ends |
| * have settled. On one hand, that may result in graph changes. On |
| * the other, this requires that the caller either runs in the main |
| * loop; or that all involved nodes (@bs and all of its parents) are |
| * in the caller's AioContext. |
| */ |
| void bdrv_drained_end(BlockDriverState *bs); |
| |
| /** |
| * End a quiescent section started by bdrv_subtree_drained_begin(). |
| */ |
| void bdrv_subtree_drained_end(BlockDriverState *bs); |
| |
| #endif /* BLOCK_IO_H */ |
