/* * 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_INT_H #define BLOCK_INT_H #include "block/accounting.h" #include "block/block.h" #include "qemu/option.h" #include "qemu/queue.h" #include "block/coroutine.h" #include "qemu/timer.h" #include "qapi-types.h" #include "qapi/qmp/qerror.h" #include "monitor/monitor.h" #include "qemu/hbitmap.h" #include "block/snapshot.h" #include "qemu/main-loop.h" #include "qemu/throttle.h" #define BLOCK_FLAG_ENCRYPT 1 #define BLOCK_FLAG_COMPAT6 4 #define BLOCK_FLAG_LAZY_REFCOUNTS 8 #define BLOCK_OPT_SIZE "size" #define BLOCK_OPT_ENCRYPT "encryption" #define BLOCK_OPT_COMPAT6 "compat6" #define BLOCK_OPT_BACKING_FILE "backing_file" #define BLOCK_OPT_BACKING_FMT "backing_fmt" #define BLOCK_OPT_CLUSTER_SIZE "cluster_size" #define BLOCK_OPT_TABLE_SIZE "table_size" #define BLOCK_OPT_PREALLOC "preallocation" #define BLOCK_OPT_SUBFMT "subformat" #define BLOCK_OPT_COMPAT_LEVEL "compat" #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts" #define BLOCK_OPT_ADAPTER_TYPE "adapter_type" #define BLOCK_OPT_REDUNDANCY "redundancy" #define BLOCK_OPT_NOCOW "nocow" #define BLOCK_PROBE_BUF_SIZE 512 typedef struct BdrvTrackedRequest { BlockDriverState *bs; int64_t offset; unsigned int bytes; bool is_write; bool serialising; int64_t overlap_offset; unsigned int overlap_bytes; QLIST_ENTRY(BdrvTrackedRequest) list; Coroutine *co; /* owner, used for deadlock detection */ CoQueue wait_queue; /* coroutines blocked on this request */ struct BdrvTrackedRequest *waiting_for; } BdrvTrackedRequest; struct BlockDriver { const char *format_name; int instance_size; /* set to true if the BlockDriver is a block filter */ bool is_filter; /* for snapshots block filter like Quorum can implement the * following recursive callback. * It's purpose is to recurse on the filter children while calling * bdrv_recurse_is_first_non_filter on them. * For a sample implementation look in the future Quorum block filter. */ bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs, BlockDriverState *candidate); int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename); int (*bdrv_probe_device)(const char *filename); /* Any driver implementing this callback is expected to be able to handle * NULL file names in its .bdrv_open() implementation */ void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp); /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have * this field set to true, except ones that are defined only by their * child's bs. * An example of the last type will be the quorum block driver. */ bool bdrv_needs_filename; /* Set if a driver can support backing files */ bool supports_backing; /* For handling image reopen for split or non-split files */ int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state, BlockReopenQueue *queue, Error **errp); void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state); void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state); int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, Error **errp); int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, Error **errp); int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors); int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors); void (*bdrv_close)(BlockDriverState *bs); void (*bdrv_rebind)(BlockDriverState *bs); int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp); int (*bdrv_set_key)(BlockDriverState *bs, const char *key); int (*bdrv_make_empty)(BlockDriverState *bs); void (*bdrv_refresh_filename)(BlockDriverState *bs); /* aio */ BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, BlockCompletionFunc *cb, void *opaque); BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, BlockCompletionFunc *cb, void *opaque); int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); /* * Efficiently zero a region of the disk image. Typically an image format * would use a compact metadata representation to implement this. This * function pointer may be NULL and .bdrv_co_writev() will be called * instead. */ int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs, int64_t sector_num, int nb_sectors); int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum); /* * Invalidate any cached meta-data. */ void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp); /* * Flushes all data that was already written to the OS all the way down to * the disk (for example raw-posix calls fsync()). */ int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs); /* * Flushes all internal caches to the OS. The data may still sit in a * writeback cache of the host OS, but it will survive a crash of the qemu * process. */ int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs); const char *protocol_name; int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset); int64_t (*bdrv_getlength)(BlockDriverState *bs); bool has_variable_length; int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors); int (*bdrv_snapshot_create)(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); int (*bdrv_snapshot_goto)(BlockDriverState *bs, const char *snapshot_id); int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id, const char *name, Error **errp); int (*bdrv_snapshot_list)(BlockDriverState *bs, QEMUSnapshotInfo **psn_info); int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs, const char *snapshot_id, const char *name, Error **errp); int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi); ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs); int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size); int (*bdrv_change_backing_file)(BlockDriverState *bs, const char *backing_file, const char *backing_fmt); /* removable device specific */ int (*bdrv_is_inserted)(BlockDriverState *bs); int (*bdrv_media_changed)(BlockDriverState *bs); void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); /* to control generic scsi devices */ int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque); /* List of options for creating images, terminated by name == NULL */ QemuOptsList *create_opts; /* * Returns 0 for completed check, -errno for internal errors. * The check results are stored in result. */ int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result, BdrvCheckMode fix); int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts, BlockDriverAmendStatusCB *status_cb); void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event); /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */ int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event, const char *tag); int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs, const char *tag); int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag); bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag); void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp); /* * Returns 1 if newly created images are guaranteed to contain only * zeros, 0 otherwise. */ int (*bdrv_has_zero_init)(BlockDriverState *bs); /* Remove fd handlers, timers, and other event loop callbacks so the event * loop is no longer in use. Called with no in-flight requests and in * depth-first traversal order with parents before child nodes. */ void (*bdrv_detach_aio_context)(BlockDriverState *bs); /* Add fd handlers, timers, and other event loop callbacks so I/O requests * can be processed again. Called with no in-flight requests and in * depth-first traversal order with child nodes before parent nodes. */ void (*bdrv_attach_aio_context)(BlockDriverState *bs, AioContext *new_context); /* io queue for linux-aio */ void (*bdrv_io_plug)(BlockDriverState *bs); void (*bdrv_io_unplug)(BlockDriverState *bs); void (*bdrv_flush_io_queue)(BlockDriverState *bs); QLIST_ENTRY(BlockDriver) list; }; typedef struct BlockLimits { /* maximum number of sectors that can be discarded at once */ int max_discard; /* optimal alignment for discard requests in sectors */ int64_t discard_alignment; /* maximum number of sectors that can zeroized at once */ int max_write_zeroes; /* optimal alignment for write zeroes requests in sectors */ int64_t write_zeroes_alignment; /* optimal transfer length in sectors */ int opt_transfer_length; /* maximal transfer length in sectors */ int max_transfer_length; /* memory alignment so that no bounce buffer is needed */ size_t opt_mem_alignment; } BlockLimits; typedef struct BdrvOpBlocker BdrvOpBlocker; typedef struct BdrvAioNotifier { void (*attached_aio_context)(AioContext *new_context, void *opaque); void (*detach_aio_context)(void *opaque); void *opaque; QLIST_ENTRY(BdrvAioNotifier) list; } BdrvAioNotifier; /* * Note: the function bdrv_append() copies and swaps contents of * BlockDriverStates, so if you add new fields to this struct, please * inspect bdrv_append() to determine if the new fields need to be * copied as well. */ struct BlockDriverState { int64_t total_sectors; /* if we are reading a disk image, give its size in sectors */ int read_only; /* if true, the media is read only */ int open_flags; /* flags used to open the file, re-used for re-open */ int encrypted; /* if true, the media is encrypted */ int valid_key; /* if true, a valid encryption key has been set */ int sg; /* if true, the device is a /dev/sg* */ int copy_on_read; /* if true, copy read backing sectors into image note this is a reference count */ bool probed; BlockDriver *drv; /* NULL means no media */ void *opaque; BlockBackend *blk; /* owning backend, if any */ AioContext *aio_context; /* event loop used for fd handlers, timers, etc */ /* long-running tasks intended to always use the same AioContext as this * BDS may register themselves in this list to be notified of changes * regarding this BDS's context */ QLIST_HEAD(, BdrvAioNotifier) aio_notifiers; char filename[PATH_MAX]; char backing_file[PATH_MAX]; /* if non zero, the image is a diff of this file image */ char backing_format[16]; /* if non-zero and backing_file exists */ QDict *full_open_options; char exact_filename[PATH_MAX]; BlockDriverState *backing_hd; BlockDriverState *file; NotifierList close_notifiers; /* Callback before write request is processed */ NotifierWithReturnList before_write_notifiers; /* number of in-flight serialising requests */ unsigned int serialising_in_flight; /* I/O throttling */ ThrottleState throttle_state; CoQueue throttled_reqs[2]; bool io_limits_enabled; /* I/O stats (display with "info blockstats"). */ BlockAcctStats stats; /* I/O Limits */ BlockLimits bl; /* Whether the disk can expand beyond total_sectors */ int growable; /* Whether produces zeros when read beyond eof */ bool zero_beyond_eof; /* Alignment requirement for offset/length of I/O requests */ unsigned int request_alignment; /* the block size for which the guest device expects atomicity */ int guest_block_size; /* do we need to tell the quest if we have a volatile write cache? */ int enable_write_cache; /* NOTE: the following infos are only hints for real hardware drivers. They are not used by the block driver */ BlockdevOnError on_read_error, on_write_error; bool iostatus_enabled; BlockDeviceIoStatus iostatus; /* the following member gives a name to every node on the bs graph. */ char node_name[32]; /* element of the list of named nodes building the graph */ QTAILQ_ENTRY(BlockDriverState) node_list; /* element of the list of "drives" the guest sees */ QTAILQ_ENTRY(BlockDriverState) device_list; QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; int refcnt; QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; /* operation blockers */ QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX]; /* long-running background operation */ BlockJob *job; QDict *options; BlockdevDetectZeroesOptions detect_zeroes; /* The error object in use for blocking operations on backing_hd */ Error *backing_blocker; /* threshold limit for writes, in bytes. "High water mark". */ uint64_t write_threshold_offset; NotifierWithReturn write_threshold_notifier; }; /* Essential block drivers which must always be statically linked into qemu, and * which therefore can be accessed without using bdrv_find_format() */ extern BlockDriver bdrv_file; extern BlockDriver bdrv_raw; extern BlockDriver bdrv_qcow2; int get_tmp_filename(char *filename, int size); BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, const char *filename); void bdrv_set_io_limits(BlockDriverState *bs, ThrottleConfig *cfg); /** * bdrv_add_before_write_notifier: * * Register a callback that is invoked before write requests are processed but * after any throttling or waiting for overlapping requests. */ void bdrv_add_before_write_notifier(BlockDriverState *bs, NotifierWithReturn *notifier); /** * bdrv_detach_aio_context: * * May be called from .bdrv_detach_aio_context() to detach children from the * current #AioContext. This is only needed by block drivers that manage their * own children. Both ->file and ->backing_hd are automatically handled and * block drivers should not call this function on them explicitly. */ void bdrv_detach_aio_context(BlockDriverState *bs); /** * bdrv_attach_aio_context: * * May be called from .bdrv_attach_aio_context() to attach children to the new * #AioContext. This is only needed by block drivers that manage their own * children. Both ->file and ->backing_hd are automatically handled and block * drivers should not call this function on them explicitly. */ void bdrv_attach_aio_context(BlockDriverState *bs, AioContext *new_context); /** * bdrv_add_aio_context_notifier: * * If a long-running job intends to be always run in the same AioContext as a * certain BDS, it may use this function to be notified of changes regarding the * association of the BDS to an AioContext. * * attached_aio_context() is called after the target BDS has been attached to a * new AioContext; detach_aio_context() is called before the target BDS is being * detached from its old AioContext. */ void bdrv_add_aio_context_notifier(BlockDriverState *bs, void (*attached_aio_context)(AioContext *new_context, void *opaque), void (*detach_aio_context)(void *opaque), void *opaque); /** * bdrv_remove_aio_context_notifier: * * Unsubscribe of change notifications regarding the BDS's AioContext. The * parameters given here have to be the same as those given to * bdrv_add_aio_context_notifier(). */ void bdrv_remove_aio_context_notifier(BlockDriverState *bs, void (*aio_context_attached)(AioContext *, void *), void (*aio_context_detached)(void *), void *opaque); #ifdef _WIN32 int is_windows_drive(const char *filename); #endif /** * stream_start: * @bs: Block device to operate on. * @base: Block device that will become the new base, or %NULL to * flatten the whole backing file chain onto @bs. * @base_id: The file name that will be written to @bs as the new * backing file if the job completes. Ignored if @base is %NULL. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @on_error: The action to take upon error. * @cb: Completion function for the job. * @opaque: Opaque pointer value passed to @cb. * @errp: Error object. * * Start a streaming operation on @bs. Clusters that are unallocated * in @bs, but allocated in any image between @base and @bs (both * exclusive) will be written to @bs. At the end of a successful * streaming job, the backing file of @bs will be changed to * @base_id in the written image and to @base in the live BlockDriverState. */ void stream_start(BlockDriverState *bs, BlockDriverState *base, const char *base_id, int64_t speed, BlockdevOnError on_error, BlockCompletionFunc *cb, void *opaque, Error **errp); /** * commit_start: * @bs: Active block device. * @top: Top block device to be committed. * @base: Block device that will be written into, and become the new top. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @on_error: The action to take upon error. * @cb: Completion function for the job. * @opaque: Opaque pointer value passed to @cb. * @backing_file_str: String to use as the backing file in @top's overlay * @errp: Error object. * */ void commit_start(BlockDriverState *bs, BlockDriverState *base, BlockDriverState *top, int64_t speed, BlockdevOnError on_error, BlockCompletionFunc *cb, void *opaque, const char *backing_file_str, Error **errp); /** * commit_active_start: * @bs: Active block device to be committed. * @base: Block device that will be written into, and become the new top. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @on_error: The action to take upon error. * @cb: Completion function for the job. * @opaque: Opaque pointer value passed to @cb. * @errp: Error object. * */ void commit_active_start(BlockDriverState *bs, BlockDriverState *base, int64_t speed, BlockdevOnError on_error, BlockCompletionFunc *cb, void *opaque, Error **errp); /* * mirror_start: * @bs: Block device to operate on. * @target: Block device to write to. * @replaces: Block graph node name to replace once the mirror is done. Can * only be used when full mirroring is selected. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @granularity: The chosen granularity for the dirty bitmap. * @buf_size: The amount of data that can be in flight at one time. * @mode: Whether to collapse all images in the chain to the target. * @on_source_error: The action to take upon error reading from the source. * @on_target_error: The action to take upon error writing to the target. * @cb: Completion function for the job. * @opaque: Opaque pointer value passed to @cb. * @errp: Error object. * * Start a mirroring operation on @bs. Clusters that are allocated * in @bs will be written to @bs until the job is cancelled or * manually completed. At the end of a successful mirroring job, * @bs will be switched to read from @target. */ void mirror_start(BlockDriverState *bs, BlockDriverState *target, const char *replaces, int64_t speed, int64_t granularity, int64_t buf_size, MirrorSyncMode mode, BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockCompletionFunc *cb, void *opaque, Error **errp); /* * backup_start: * @bs: Block device to operate on. * @target: Block device to write to. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @sync_mode: What parts of the disk image should be copied to the destination. * @on_source_error: The action to take upon error reading from the source. * @on_target_error: The action to take upon error writing to the target. * @cb: Completion function for the job. * @opaque: Opaque pointer value passed to @cb. * * Start a backup operation on @bs. Clusters in @bs are written to @target * until the job is cancelled or manually completed. */ void backup_start(BlockDriverState *bs, BlockDriverState *target, int64_t speed, MirrorSyncMode sync_mode, BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockCompletionFunc *cb, void *opaque, Error **errp); void blk_dev_change_media_cb(BlockBackend *blk, bool load); bool blk_dev_has_removable_media(BlockBackend *blk); void blk_dev_eject_request(BlockBackend *blk, bool force); bool blk_dev_is_tray_open(BlockBackend *blk); bool blk_dev_is_medium_locked(BlockBackend *blk); void blk_dev_resize_cb(BlockBackend *blk); #endif /* BLOCK_INT_H */