| /* |
| * 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 "qemu/coroutine.h" |
| #include "qemu/stats64.h" |
| #include "qemu/timer.h" |
| #include "qapi-types.h" |
| #include "qemu/hbitmap.h" |
| #include "block/snapshot.h" |
| #include "qemu/main-loop.h" |
| #include "qemu/throttle.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, |
| }; |
| |
| typedef struct BdrvTrackedRequest { |
| BlockDriverState *bs; |
| int64_t offset; |
| unsigned int bytes; |
| enum BdrvTrackedRequestType type; |
| |
| 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); |
| void (*bdrv_join_options)(QDict *options, QDict *old_options); |
| |
| int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp); |
| int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp); |
| void (*bdrv_close)(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, QDict *options); |
| |
| /* 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_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); |
| 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 coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags); |
| 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); |
| |
| /* |
| * Building block for bdrv_block_status[_above]. The driver should |
| * answer only according to the current layer, and should not |
| * set BDRV_BLOCK_ALLOCATED, but may set BDRV_BLOCK_RAW. See block.h |
| * for the meaning of _DATA, _ZERO, and _OFFSET_VALID. |
| */ |
| int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, int *pnum, |
| BlockDriverState **file); |
| |
| /* |
| * Invalidate any cached meta-data. |
| */ |
| void (*bdrv_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); |
| |
| const char *protocol_name; |
| int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset, Error **errp); |
| |
| int64_t (*bdrv_getlength)(BlockDriverState *bs); |
| bool has_variable_length; |
| int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); |
| |
| 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); |
| 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 */ |
| 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 (*bdrv_check)(BlockDriverState *bs, BdrvCheckResult *result, |
| BdrvCheckMode fix); |
| |
| int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts, |
| BlockDriverAmendStatusCB *status_cb, |
| void *cb_opaque); |
| |
| 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); |
| |
| /** |
| * Drain and stop any internal sources of requests in the driver, and |
| * remain so until next I/O callback (e.g. bdrv_co_writev) is called. |
| */ |
| void (*bdrv_drain)(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. |
| */ |
| void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c, |
| const BdrvChildRole *role, |
| uint64_t parent_perm, uint64_t parent_shared, |
| uint64_t *nperm, uint64_t *nshared); |
| |
| 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; |
| |
| 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. |
| * |
| * 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); |
| |
| /* 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); |
| }; |
| |
| 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 valid_key; /* if true, a valid encryption key has been set */ |
| 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 */ |
| |
| 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) */ |
| unsigned int supported_write_flags; |
| /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA, |
| * BDRV_REQ_MAY_UNMAP) */ |
| 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; |
| |
| /* Internal to BDRV_POLL_WHILE and bdrv_wakeup. Accessed with atomic |
| * ops. |
| */ |
| bool wakeup; |
| |
| /* 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; |
| 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); |
| |
| 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. |
| * @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, |
| 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. |
| * @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, 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. |
| * @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. |
| * @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, |
| 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, 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, |
| BlockJobTxn *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, |
| 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, |
| uint64_t perm, uint64_t shared, |
| uint64_t *nperm, uint64_t *nshared); |
| |
| 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 cur_sector, int64_t nr_sect); |
| bool bdrv_requests_pending(BlockDriverState *bs); |
| |
| void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out); |
| void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in); |
| |
| void bdrv_inc_in_flight(BlockDriverState *bs); |
| void bdrv_dec_in_flight(BlockDriverState *bs); |
| |
| void blockdev_close_all_bdrv_states(void); |
| |
| #endif /* BLOCK_INT_H */ |