diff options
Diffstat (limited to 'include/block/block_int.h')
| -rw-r--r-- | include/block/block_int.h | 1153 |
1 files changed, 4 insertions, 1149 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index f605622216..567a178e13 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -24,1155 +24,10 @@ #ifndef BLOCK_INT_H #define BLOCK_INT_H -#include "block/accounting.h" -#include "block/block.h" -#include "block/aio-wait.h" -#include "qemu/queue.h" -#include "qemu/coroutine.h" -#include "qemu/stats64.h" -#include "qemu/timer.h" -#include "qemu/hbitmap.h" -#include "block/snapshot.h" -#include "qemu/main-loop.h" -#include "qemu/throttle.h" +#include "block/block_int-global-state.h" +#include "block/block_int-io.h" +#include "block/graph-lock.h" -#define BLOCK_FLAG_LAZY_REFCOUNTS 8 - -#define BLOCK_OPT_SIZE "size" -#define BLOCK_OPT_ENCRYPT "encryption" -#define BLOCK_OPT_ENCRYPT_FORMAT "encrypt.format" -#define BLOCK_OPT_COMPAT6 "compat6" -#define BLOCK_OPT_HWVERSION "hwversion" -#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_OPT_OBJECT_SIZE "object_size" -#define BLOCK_OPT_REFCOUNT_BITS "refcount_bits" - -#define BLOCK_PROBE_BUF_SIZE 512 - -enum BdrvTrackedRequestType { - BDRV_TRACKED_READ, - BDRV_TRACKED_WRITE, - BDRV_TRACKED_DISCARD, - BDRV_TRACKED_TRUNCATE, -}; - -typedef struct BdrvTrackedRequest { - BlockDriverState *bs; - int64_t offset; - uint64_t bytes; - enum BdrvTrackedRequestType type; - - bool serialising; - int64_t overlap_offset; - uint64_t 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. Block filters pass - * certain callbacks that refer to data (see block.c) to their bs->file if - * the driver doesn't implement them. Drivers that do not wish to forward - * must implement them and return -ENOTSUP. - */ - 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); - void (*bdrv_join_options)(QDict *options, QDict *old_options); - - int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, - Error **errp); - - /* Protocol drivers should implement this instead of bdrv_open */ - int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, - Error **errp); - void (*bdrv_close)(BlockDriverState *bs); - int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts, - Error **errp); - int coroutine_fn (*bdrv_co_create_opts)(const char *filename, - QemuOpts *opts, - Error **errp); - int (*bdrv_make_empty)(BlockDriverState *bs); - - void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options); - - /* aio */ - BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags, - BlockCompletionFunc *cb, void *opaque); - BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags, - BlockCompletionFunc *cb, void *opaque); - BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs, - BlockCompletionFunc *cb, void *opaque); - BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs, - int64_t offset, int bytes, - BlockCompletionFunc *cb, void *opaque); - - int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, QEMUIOVector *qiov); - - /** - * @offset: position in bytes to read at - * @bytes: number of bytes to read - * @qiov: the buffers to fill with read data - * @flags: currently unused, always 0 - * - * @offset and @bytes will be a multiple of 'request_alignment', - * but the length of individual @qiov elements does not have to - * be a multiple. - * - * @bytes will always equal the total size of @qiov, and will be - * no larger than 'max_transfer'. - * - * The buffer in @qiov may point directly to guest memory. - */ - int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); - int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags); - /** - * @offset: position in bytes to write at - * @bytes: number of bytes to write - * @qiov: the buffers containing data to write - * @flags: zero or more bits allowed by 'supported_write_flags' - * - * @offset and @bytes will be a multiple of 'request_alignment', - * but the length of individual @qiov elements does not have to - * be a multiple. - * - * @bytes will always equal the total size of @qiov, and will be - * no larger than 'max_transfer'. - * - * The buffer in @qiov may point directly to guest memory. - */ - int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags); - - /* - * 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 or return -ENOSUP and .bdrv_co_writev() - * will be called instead. - */ - int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs, - int64_t offset, int bytes, BdrvRequestFlags flags); - int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs, - int64_t offset, int bytes); - - /* Map [offset, offset + nbytes) range onto a child of @bs to copy from, - * and invoke bdrv_co_copy_range_from(child, ...), or invoke - * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from. - * - * See the comment of bdrv_co_copy_range for the parameter and return value - * semantics. - */ - int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs, - BdrvChild *src, - uint64_t offset, - BdrvChild *dst, - uint64_t dst_offset, - uint64_t bytes, - BdrvRequestFlags read_flags, - BdrvRequestFlags write_flags); - - /* Map [offset, offset + nbytes) range onto a child of bs to copy data to, - * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy - * operation if @bs is the leaf and @src has the same BlockDriver. Return - * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver. - * - * See the comment of bdrv_co_copy_range for the parameter and return value - * semantics. - */ - int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs, - BdrvChild *src, - uint64_t src_offset, - BdrvChild *dst, - uint64_t dst_offset, - uint64_t bytes, - BdrvRequestFlags read_flags, - BdrvRequestFlags write_flags); - - /* - * Building block for bdrv_block_status[_above] and - * bdrv_is_allocated[_above]. The driver should answer only - * according to the current layer, and should only need to set - * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID, - * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing - * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). See - * block.h for the overall meaning of the bits. As a hint, the - * flag want_zero is true if the caller cares more about precise - * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for - * overall allocation (favor larger *pnum, perhaps by reporting - * _DATA instead of _ZERO). The block layer guarantees input - * clamped to bdrv_getlength() and aligned to request_alignment, - * as well as non-NULL pnum, map, and file; in turn, the driver - * must return an error or set pnum to an aligned non-zero value. - */ - int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs, - bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, - int64_t *map, BlockDriverState **file); - - /* - * Invalidate any cached meta-data. - */ - void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs, - Error **errp); - int (*bdrv_inactivate)(BlockDriverState *bs); - - /* - * Flushes all data for all layers by calling bdrv_co_flush for underlying - * layers, if needed. This function is needed for deterministic - * synchronization of the flush finishing callback. - */ - int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs); - - /* - * Flushes all data that was already written to the OS all the way down to - * the disk (for example file-posix.c 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); - - /* - * Drivers setting this field must be able to work with just a plain - * filename with '<protocol_name>:' as a prefix, and no other options. - * Options may be extracted from the filename by implementing - * bdrv_parse_filename. - */ - const char *protocol_name; - int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset, - PreallocMode prealloc, Error **errp); - - int64_t (*bdrv_getlength)(BlockDriverState *bs); - bool has_variable_length; - int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); - BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs, - Error **errp); - - int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs, - uint64_t offset, uint64_t bytes, QEMUIOVector *qiov); - - 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 coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs, - QEMUIOVector *qiov, - int64_t pos); - int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs, - QEMUIOVector *qiov, - int64_t pos); - - int (*bdrv_change_backing_file)(BlockDriverState *bs, - const char *backing_file, const char *backing_fmt); - - /* removable device specific */ - bool (*bdrv_is_inserted)(BlockDriverState *bs); - void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag); - void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked); - - /* to control generic scsi devices */ - BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs, - unsigned long int req, void *buf, - BlockCompletionFunc *cb, void *opaque); - int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs, - unsigned long int req, void *buf); - - /* 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 coroutine_fn (*bdrv_co_check)(BlockDriverState *bs, - BdrvCheckResult *result, - BdrvCheckMode fix); - - int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts, - BlockDriverAmendStatusCB *status_cb, - void *cb_opaque, - Error **errp); - - 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); - - /** - * Try to get @bs's logical and physical block size. - * On success, store them in @bsz and return zero. - * On failure, return negative errno. - */ - int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz); - /** - * Try to get @bs's geometry (cyls, heads, sectors) - * On success, store them in @geo and return 0. - * On failure return -errno. - * Only drivers that want to override guest geometry implement this - * callback; see hd_geometry_guess(). - */ - int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo); - - /** - * bdrv_co_drain_begin is called if implemented in the beginning of a - * drain operation to drain and stop any internal sources of requests in - * the driver. - * bdrv_co_drain_end is called if implemented at the end of the drain. - * - * They should be used by the driver to e.g. manage scheduled I/O - * requests, or toggle an internal state. After the end of the drain new - * requests will continue normally. - */ - void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs); - void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs); - - void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child, - Error **errp); - void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child, - Error **errp); - - /** - * Informs the block driver that a permission change is intended. The - * driver checks whether the change is permissible and may take other - * preparations for the change (e.g. get file system locks). This operation - * is always followed either by a call to either .bdrv_set_perm or - * .bdrv_abort_perm_update. - * - * Checks whether the requested set of cumulative permissions in @perm - * can be granted for accessing @bs and whether no other users are using - * permissions other than those given in @shared (both arguments take - * BLK_PERM_* bitmasks). - * - * If both conditions are met, 0 is returned. Otherwise, -errno is returned - * and errp is set to an error describing the conflict. - */ - int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm, - uint64_t shared, Error **errp); - - /** - * Called to inform the driver that the set of cumulative set of used - * permissions for @bs has changed to @perm, and the set of sharable - * permission to @shared. The driver can use this to propagate changes to - * its children (i.e. request permissions only if a parent actually needs - * them). - * - * This function is only invoked after bdrv_check_perm(), so block drivers - * may rely on preparations made in their .bdrv_check_perm implementation. - */ - void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared); - - /* - * Called to inform the driver that after a previous bdrv_check_perm() - * call, the permission update is not performed and any preparations made - * for it (e.g. taken file locks) need to be undone. - * - * This function can be called even for nodes that never saw a - * bdrv_check_perm() call. It is a no-op then. - */ - void (*bdrv_abort_perm_update)(BlockDriverState *bs); - - /** - * Returns in @nperm and @nshared the permissions that the driver for @bs - * needs on its child @c, based on the cumulative permissions requested by - * the parents in @parent_perm and @parent_shared. - * - * If @c is NULL, return the permissions for attaching a new child for the - * given @role. - * - * If @reopen_queue is non-NULL, don't return the currently needed - * permissions, but those that will be needed after applying the - * @reopen_queue. - */ - void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c, - const BdrvChildRole *role, - BlockReopenQueue *reopen_queue, - uint64_t parent_perm, uint64_t parent_shared, - uint64_t *nperm, uint64_t *nshared); - - /** - * Bitmaps should be marked as 'IN_USE' in the image on reopening image - * as rw. This handler should realize it. It also should unset readonly - * field of BlockDirtyBitmap's in case of success. - */ - int (*bdrv_reopen_bitmaps_rw)(BlockDriverState *bs, Error **errp); - bool (*bdrv_can_store_new_dirty_bitmap)(BlockDriverState *bs, - const char *name, - uint32_t granularity, - Error **errp); - void (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs, - const char *name, - Error **errp); - - /** - * Register/unregister a buffer for I/O. For example, when the driver is - * interested to know the memory areas that will later be used in iovs, so - * that it can do IOMMU mapping with VFIO etc., in order to get better - * performance. In the case of VFIO drivers, this callback is used to do - * DMA mapping for hot buffers. - */ - void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size); - void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host); - QLIST_ENTRY(BlockDriver) list; -}; - -typedef struct BlockLimits { - /* Alignment requirement, in bytes, for offset/length of I/O - * requests. Must be a power of 2 less than INT_MAX; defaults to - * 1 for drivers with modern byte interfaces, and to 512 - * otherwise. */ - uint32_t request_alignment; - - /* Maximum number of bytes that can be discarded at once (since it - * is signed, it must be < 2G, if set). Must be multiple of - * pdiscard_alignment, but need not be power of 2. May be 0 if no - * inherent 32-bit limit */ - int32_t max_pdiscard; - - /* Optimal alignment for discard requests in bytes. A power of 2 - * is best but not mandatory. Must be a multiple of - * bl.request_alignment, and must be less than max_pdiscard if - * that is set. May be 0 if bl.request_alignment is good enough */ - uint32_t pdiscard_alignment; - - /* Maximum number of bytes that can zeroized at once (since it is - * signed, it must be < 2G, if set). Must be multiple of - * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */ - int32_t max_pwrite_zeroes; - - /* Optimal alignment for write zeroes requests in bytes. A power - * of 2 is best but not mandatory. Must be a multiple of - * bl.request_alignment, and must be less than max_pwrite_zeroes - * if that is set. May be 0 if bl.request_alignment is good - * enough */ - uint32_t pwrite_zeroes_alignment; - - /* Optimal transfer length in bytes. A power of 2 is best but not - * mandatory. Must be a multiple of bl.request_alignment, or 0 if - * no preferred size */ - uint32_t opt_transfer; - - /* Maximal transfer length in bytes. Need not be power of 2, but - * must be multiple of opt_transfer and bl.request_alignment, or 0 - * for no 32-bit limit. For now, anything larger than INT_MAX is - * clamped down. */ - uint32_t max_transfer; - - /* memory alignment, in bytes so that no bounce buffer is needed */ - size_t min_mem_alignment; - - /* memory alignment, in bytes, for bounce buffer */ - size_t opt_mem_alignment; - - /* maximum number of iovec elements */ - int max_iov; -} 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; - bool deleted; - - QLIST_ENTRY(BdrvAioNotifier) list; -} BdrvAioNotifier; - -struct BdrvChildRole { - /* If true, bdrv_replace_node() doesn't change the node this BdrvChild - * points to. */ - bool stay_at_node; - - /* If true, the parent is a BlockDriverState and bdrv_next_all_states() - * will return it. This information is used for drain_all, where every node - * will be drained separately, so the drain only needs to be propagated to - * non-BDS parents. */ - bool parent_is_bds; - - void (*inherit_options)(int *child_flags, QDict *child_options, - int parent_flags, QDict *parent_options); - - void (*change_media)(BdrvChild *child, bool load); - void (*resize)(BdrvChild *child); - - /* Returns a name that is supposedly more useful for human users than the - * node name for identifying the node in question (in particular, a BB - * name), or NULL if the parent can't provide a better name. */ - const char *(*get_name)(BdrvChild *child); - - /* Returns a malloced string that describes the parent of the child for a - * human reader. This could be a node-name, BlockBackend name, qdev ID or - * QOM path of the device owning the BlockBackend, job type and ID etc. The - * caller is responsible for freeing the memory. */ - char *(*get_parent_desc)(BdrvChild *child); - - /* - * If this pair of functions is implemented, the parent doesn't issue new - * requests after returning from .drained_begin() until .drained_end() is - * called. - * - * These functions must not change the graph (and therefore also must not - * call aio_poll(), which could change the graph indirectly). - * - * Note that this can be nested. If drained_begin() was called twice, new - * I/O is allowed only after drained_end() was called twice, too. - */ - void (*drained_begin)(BdrvChild *child); - void (*drained_end)(BdrvChild *child); - - /* - * Returns whether the parent has pending requests for the child. This - * callback is polled after .drained_begin() has been called until all - * activity on the child has stopped. - */ - bool (*drained_poll)(BdrvChild *child); - - /* Notifies the parent that the child has been activated/inactivated (e.g. - * when migration is completing) and it can start/stop requesting - * permissions and doing I/O on it. */ - void (*activate)(BdrvChild *child, Error **errp); - int (*inactivate)(BdrvChild *child); - - void (*attach)(BdrvChild *child); - void (*detach)(BdrvChild *child); - - /* Notifies the parent that the filename of its child has changed (e.g. - * because the direct child was removed from the backing chain), so that it - * can update its reference. */ - int (*update_filename)(BdrvChild *child, BlockDriverState *new_base, - const char *filename, Error **errp); -}; - -extern const BdrvChildRole child_file; -extern const BdrvChildRole child_format; -extern const BdrvChildRole child_backing; - -struct BdrvChild { - BlockDriverState *bs; - char *name; - const BdrvChildRole *role; - void *opaque; - - /** - * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask) - */ - uint64_t perm; - - /** - * Permissions that can still be granted to other users of @bs while this - * BdrvChild is still attached to it. (BLK_PERM_* bitmask) - */ - uint64_t shared_perm; - - QLIST_ENTRY(BdrvChild) next; - QLIST_ENTRY(BdrvChild) next_parent; -}; - -/* - * 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 { - /* Protected by big QEMU lock or read-only after opening. No special - * locking needed during I/O... - */ - int open_flags; /* flags used to open the file, re-used for re-open */ - bool read_only; /* if true, the media is read only */ - bool encrypted; /* if true, the media is encrypted */ - bool sg; /* if true, the device is a /dev/sg* */ - bool probed; /* if true, format was probed rather than specified */ - bool force_share; /* if true, always allow all shared permissions */ - bool implicit; /* if true, this filter node was automatically inserted */ - - BlockDriver *drv; /* NULL means no media */ - void *opaque; - - 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; - bool walking_aio_notifiers; /* to make removal during iteration safe */ - - 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]; - - BdrvChild *backing; - BdrvChild *file; - - /* I/O Limits */ - BlockLimits bl; - - /* Flags honored during pwrite (so far: BDRV_REQ_FUA, - * BDRV_REQ_WRITE_UNCHANGED). - * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those - * writes will be issued as normal writes without the flag set. - * This is important to note for drivers that do not explicitly - * request a WRITE permission for their children and instead take - * the same permissions as their parent did (this is commonly what - * block filters do). Such drivers have to be aware that the - * parent may have taken a WRITE_UNCHANGED permission only and is - * issuing such requests. Drivers either must make sure that - * these requests do not result in plain WRITE accesses (usually - * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding - * every incoming write request as-is, including potentially that - * flag), or they have to explicitly take the WRITE permission for - * their children. */ - unsigned int supported_write_flags; - /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA, - * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */ - unsigned int supported_zero_flags; - - /* 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 all BlockDriverStates (all_bdrv_states) */ - QTAILQ_ENTRY(BlockDriverState) bs_list; - /* element of the list of monitor-owned BDS */ - QTAILQ_ENTRY(BlockDriverState) monitor_list; - int refcnt; - - /* operation blockers */ - QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX]; - - /* long-running background operation */ - BlockJob *job; - - /* The node that this node inherited default options from (and a reopen on - * which can affect this node by changing these defaults). This is always a - * parent node of this node. */ - BlockDriverState *inherits_from; - QLIST_HEAD(, BdrvChild) children; - QLIST_HEAD(, BdrvChild) parents; - - QDict *options; - QDict *explicit_options; - BlockdevDetectZeroesOptions detect_zeroes; - - /* The error object in use for blocking operations on backing_hd */ - Error *backing_blocker; - - /* Protected by AioContext lock */ - - /* If we are reading a disk image, give its size in sectors. - * Generally read-only; it is written to by load_snapshot and - * save_snaphost, but the block layer is quiescent during those. - */ - int64_t total_sectors; - - /* Callback before write request is processed */ - NotifierWithReturnList before_write_notifiers; - - /* threshold limit for writes, in bytes. "High water mark". */ - uint64_t write_threshold_offset; - NotifierWithReturn write_threshold_notifier; - - /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex. - * Reading from the list can be done with either the BQL or the - * dirty_bitmap_mutex. Modifying a bitmap only requires - * dirty_bitmap_mutex. */ - QemuMutex dirty_bitmap_mutex; - QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps; - - /* Offset after the highest byte written to */ - Stat64 wr_highest_offset; - - /* If true, copy read backing sectors into image. Can be >1 if more - * than one client has requested copy-on-read. Accessed with atomic - * ops. - */ - int copy_on_read; - - /* number of in-flight requests; overall and serialising. - * Accessed with atomic ops. - */ - unsigned int in_flight; - unsigned int serialising_in_flight; - - /* counter for nested bdrv_io_plug. - * Accessed with atomic ops. - */ - unsigned io_plugged; - - /* do we need to tell the quest if we have a volatile write cache? */ - int enable_write_cache; - - /* Accessed with atomic ops. */ - int quiesce_counter; - int recursive_quiesce_counter; - - unsigned int write_gen; /* Current data generation */ - - /* Protected by reqs_lock. */ - CoMutex reqs_lock; - QLIST_HEAD(, BdrvTrackedRequest) tracked_requests; - CoQueue flush_queue; /* Serializing flush queue */ - bool active_flush_req; /* Flush request in flight? */ - - /* Only read/written by whoever has set active_flush_req to true. */ - unsigned int flushed_gen; /* Flushed write generation */ -}; - -struct BlockBackendRootState { - int open_flags; - bool read_only; - BlockdevDetectZeroesOptions detect_zeroes; -}; - -typedef enum BlockMirrorBackingMode { - /* Reuse the existing backing chain from the source for the target. - * - sync=full: Set backing BDS to NULL. - * - sync=top: Use source's backing BDS. - * - sync=none: Use source as the backing BDS. */ - MIRROR_SOURCE_BACKING_CHAIN, - - /* Open the target's backing chain completely anew */ - MIRROR_OPEN_BACKING_CHAIN, - - /* Do not change the target's backing BDS after job completion */ - MIRROR_LEAVE_BACKING_CHAIN, -} BlockMirrorBackingMode; - -static inline BlockDriverState *backing_bs(BlockDriverState *bs) -{ - return bs->backing ? bs->backing->bs : NULL; -} - - -/* 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 coroutine_fn bdrv_co_preadv(BdrvChild *child, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags); -int coroutine_fn bdrv_co_pwritev(BdrvChild *child, - int64_t offset, unsigned int bytes, QEMUIOVector *qiov, - BdrvRequestFlags flags); - -extern unsigned int bdrv_drain_all_count; -void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent); -void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent); - -int get_tmp_filename(char *filename, int size); -BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, - const char *filename); - -void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix, - QDict *options); - - -/** - * 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 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 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); - -/** - * bdrv_wakeup: - * @bs: The BlockDriverState for which an I/O operation has been completed. - * - * Wake up the main thread if it is waiting on BDRV_POLL_WHILE. During - * synchronous I/O on a BlockDriverState that is attached to another - * I/O thread, the main thread lets the I/O thread's event loop run, - * waiting for the I/O operation to complete. A bdrv_wakeup will wake - * up the main thread if necessary. - * - * Manual calls to bdrv_wakeup are rarely necessary, because - * bdrv_dec_in_flight already calls it. - */ -void bdrv_wakeup(BlockDriverState *bs); - -#ifdef _WIN32 -int is_windows_drive(const char *filename); -#endif - -/** - * stream_start: - * @job_id: The id of the newly-created job, or %NULL to use the - * device name of @bs. - * @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. - * @backing_file_str: The file name that will be written to @bs as the - * the new backing file if the job completes. Ignored if @base is %NULL. - * @creation_flags: Flags that control the behavior of the Job lifetime. - * See @BlockJobCreateFlags - * @speed: The maximum speed, in bytes per second, or 0 for unlimited. - * @on_error: The action to take upon error. - * @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 - * @backing_file_str in the written image and to @base in the live - * BlockDriverState. - */ -void stream_start(const char *job_id, BlockDriverState *bs, - BlockDriverState *base, const char *backing_file_str, - int creation_flags, int64_t speed, - BlockdevOnError on_error, Error **errp); - -/** - * commit_start: - * @job_id: The id of the newly-created job, or %NULL to use the - * device name of @bs. - * @bs: Active block device. - * @top: Top block device to be committed. - * @base: Block device that will be written into, and become the new top. - * @creation_flags: Flags that control the behavior of the Job lifetime. - * See @BlockJobCreateFlags - * @speed: The maximum speed, in bytes per second, or 0 for unlimited. - * @on_error: The action to take upon error. - * @backing_file_str: String to use as the backing file in @top's overlay - * @filter_node_name: The node name that should be assigned to the filter - * driver that the commit job inserts into the graph above @top. NULL means - * that a node name should be autogenerated. - * @errp: Error object. - * - */ -void commit_start(const char *job_id, BlockDriverState *bs, - BlockDriverState *base, BlockDriverState *top, - int creation_flags, int64_t speed, - BlockdevOnError on_error, const char *backing_file_str, - const char *filter_node_name, Error **errp); -/** - * commit_active_start: - * @job_id: The id of the newly-created job, or %NULL to use the - * device name of @bs. - * @bs: Active block device to be committed. - * @base: Block device that will be written into, and become the new top. - * @creation_flags: Flags that control the behavior of the Job lifetime. - * See @BlockJobCreateFlags - * @speed: The maximum speed, in bytes per second, or 0 for unlimited. - * @on_error: The action to take upon error. - * @filter_node_name: The node name that should be assigned to the filter - * driver that the commit job inserts into the graph above @bs. NULL means that - * a node name should be autogenerated. - * @cb: Completion function for the job. - * @opaque: Opaque pointer value passed to @cb. - * @auto_complete: Auto complete the job. - * @errp: Error object. - * - */ -void commit_active_start(const char *job_id, BlockDriverState *bs, - BlockDriverState *base, int creation_flags, - int64_t speed, BlockdevOnError on_error, - const char *filter_node_name, - BlockCompletionFunc *cb, void *opaque, - bool auto_complete, Error **errp); -/* - * mirror_start: - * @job_id: The id of the newly-created job, or %NULL to use the - * device name of @bs. - * @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. - * @creation_flags: Flags that control the behavior of the Job lifetime. - * See @BlockJobCreateFlags - * @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. - * @backing_mode: How to establish the target's backing chain after completion. - * @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. - * @unmap: Whether to unmap target where source sectors only contain zeroes. - * @filter_node_name: The node name that should be assigned to the filter - * driver that the mirror job inserts into the graph above @bs. NULL means that - * a node name should be autogenerated. - * @copy_mode: When to trigger writes to the target. - * @errp: Error object. - * - * Start a mirroring operation on @bs. Clusters that are allocated - * in @bs will be written to @target 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(const char *job_id, BlockDriverState *bs, - BlockDriverState *target, const char *replaces, - int creation_flags, int64_t speed, - uint32_t granularity, int64_t buf_size, - MirrorSyncMode mode, BlockMirrorBackingMode backing_mode, - BlockdevOnError on_source_error, - BlockdevOnError on_target_error, - bool unmap, const char *filter_node_name, - MirrorCopyMode copy_mode, Error **errp); - -/* - * backup_job_create: - * @job_id: The id of the newly-created job, or %NULL to use the - * device name of @bs. - * @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. - * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL. - * @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. - * @creation_flags: Flags that control the behavior of the Job lifetime. - * See @BlockJobCreateFlags - * @cb: Completion function for the job. - * @opaque: Opaque pointer value passed to @cb. - * @txn: Transaction that this job is part of (may be NULL). - * - * Create a backup operation on @bs. Clusters in @bs are written to @target - * until the job is cancelled or manually completed. - */ -BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, - BlockDriverState *target, int64_t speed, - MirrorSyncMode sync_mode, - BdrvDirtyBitmap *sync_bitmap, - bool compress, - BlockdevOnError on_source_error, - BlockdevOnError on_target_error, - int creation_flags, - BlockCompletionFunc *cb, void *opaque, - JobTxn *txn, Error **errp); - -void hmp_drive_add_node(Monitor *mon, const char *optstr); - -BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, - const char *child_name, - const BdrvChildRole *child_role, - uint64_t perm, uint64_t shared_perm, - void *opaque, Error **errp); -void bdrv_root_unref_child(BdrvChild *child); - -int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, - Error **errp); - -/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by - * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to - * all children */ -void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, - const BdrvChildRole *role, - BlockReopenQueue *reopen_queue, - uint64_t perm, uint64_t shared, - uint64_t *nperm, uint64_t *nshared); - -/* Default implementation for BlockDriver.bdrv_child_perm() that can be used by - * (non-raw) image formats: Like above for bs->backing, but for bs->file it - * requires WRITE | RESIZE for read-write images, always requires - * CONSISTENT_READ and doesn't share WRITE. */ -void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, - const BdrvChildRole *role, - BlockReopenQueue *reopen_queue, - uint64_t perm, uint64_t shared, - uint64_t *nperm, uint64_t *nshared); - -/* - * Default implementation for drivers to pass bdrv_co_block_status() to - * their file. - */ -int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs, - bool want_zero, - int64_t offset, - int64_t bytes, - int64_t *pnum, - int64_t *map, - BlockDriverState **file); -/* - * Default implementation for drivers to pass bdrv_co_block_status() to - * their backing file. - */ -int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs, - bool want_zero, - int64_t offset, - int64_t bytes, - int64_t *pnum, - int64_t *map, - BlockDriverState **file); -const char *bdrv_get_parent_name(const BlockDriverState *bs); -void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp); -bool blk_dev_has_removable_media(BlockBackend *blk); -bool blk_dev_has_tray(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 bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes); - -void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out); -void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup); - -void bdrv_inc_in_flight(BlockDriverState *bs); -void bdrv_dec_in_flight(BlockDriverState *bs); - -void blockdev_close_all_bdrv_states(void); - -int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset, - BdrvChild *dst, uint64_t dst_offset, - uint64_t bytes, - BdrvRequestFlags read_flags, - BdrvRequestFlags write_flags); -int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset, - BdrvChild *dst, uint64_t dst_offset, - uint64_t bytes, - BdrvRequestFlags read_flags, - BdrvRequestFlags write_flags); - -int refresh_total_sectors(BlockDriverState *bs, int64_t hint); +/* DO NOT ADD ANYTHING IN HERE. USE ONE OF THE HEADERS INCLUDED ABOVE */ #endif /* BLOCK_INT_H */ |