diff options
Diffstat (limited to 'include/block/block_int-common.h')
| -rw-r--r-- | include/block/block_int-common.h | 63 |
1 files changed, 45 insertions, 18 deletions
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 0d8187f..034c063 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -248,7 +248,7 @@ struct BlockDriver { int GRAPH_UNLOCKED_PTR (*bdrv_open)( BlockDriverState *bs, QDict *options, int flags, Error **errp); - void (*bdrv_close)(BlockDriverState *bs); + void GRAPH_UNLOCKED_PTR (*bdrv_close)(BlockDriverState *bs); int coroutine_fn GRAPH_UNLOCKED_PTR (*bdrv_co_create)( BlockdevCreateOptions *opts, Error **errp); @@ -396,9 +396,23 @@ struct BlockDriver { int GRAPH_RDLOCK_PTR (*bdrv_probe_geometry)( BlockDriverState *bs, HDGeometry *geo); + /** + * Hot add a BDS's child. Used in combination with bdrv_del_child, so the + * user can take a child offline when it is broken and take a new child + * online. + * + * All block nodes must be drained. + */ void GRAPH_WRLOCK_PTR (*bdrv_add_child)( BlockDriverState *parent, BlockDriverState *child, Error **errp); + /** + * Hot remove a BDS's child. Used in combination with bdrv_add_child, so the + * user can take a child offline when it is broken and take a new child + * online. + * + * All block nodes must be drained. + */ void GRAPH_WRLOCK_PTR (*bdrv_del_child)( BlockDriverState *parent, BdrvChild *child, Error **errp); @@ -604,15 +618,16 @@ struct BlockDriver { * 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. + * layer, the result should be 0 (and not BDRV_BLOCK_ZERO). The + * caller will synthesize BDRV_BLOCK_ALLOCATED based on the + * non-zero results. See block.h for the overall meaning of the + * bits. As a hint, the flags in @mode may include a bitwise-or + * of BDRV_WANT_ALLOCATED, BDRV_WANT_OFFSET_VALID, or + * BDRV_WANT_ZERO based on what the caller is looking for in the + * results. 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. * * Note that @bytes is just a hint on how big of a region the * caller wants to inspect. It is not a limit on *pnum. @@ -624,8 +639,8 @@ struct BlockDriver { * to clamping *pnum for return to its caller. */ int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_block_status)( - BlockDriverState *bs, - bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, + BlockDriverState *bs, unsigned int mode, + int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); /* @@ -649,8 +664,8 @@ struct BlockDriver { QEMUIOVector *qiov, size_t qiov_offset); int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_snapshot_block_status)( - BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, - int64_t *pnum, int64_t *map, BlockDriverState **file); + BlockDriverState *bs, unsigned int mode, int64_t offset, + int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file); int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_pdiscard_snapshot)( BlockDriverState *bs, int64_t offset, int64_t bytes); @@ -982,9 +997,21 @@ struct BdrvChildClass { bool backing_mask_protocol, Error **errp); - bool (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, - GHashTable *visited, Transaction *tran, - Error **errp); + /* + * Notifies the parent that the child is trying to change its AioContext. + * The parent may in turn change the AioContext of other nodes in the same + * transaction. Returns true if the change is possible and the transaction + * can be continued. Returns false and sets @errp if not and the transaction + * must be aborted. + * + * @visited will accumulate all visited BdrvChild objects. The caller is + * responsible for freeing the list afterwards. + * + * Must be called with the affected block nodes drained. + */ + bool GRAPH_RDLOCK_PTR (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, + GHashTable *visited, + Transaction *tran, Error **errp); /* * I/O API functions. These functions are thread-safe. @@ -1226,7 +1253,7 @@ struct BlockDriverState { /* do we need to tell the quest if we have a volatile write cache? */ int enable_write_cache; - /* Accessed with atomic ops. */ + /* Accessed only in the main thread. */ int quiesce_counter; unsigned int write_gen; /* Current data generation */ |