diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/block.h | 20 | ||||
| -rw-r--r-- | include/block/block_int.h | 3 | ||||
| -rw-r--r-- | include/qemu/compiler.h | 11 |
3 files changed, 22 insertions, 12 deletions
diff --git a/include/block/block.h b/include/block/block.h index 5b81e33e94..a193545b6a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -63,16 +63,7 @@ typedef enum { * content. */ BDRV_REQ_WRITE_UNCHANGED = 0x40, - /* - * BDRV_REQ_SERIALISING forces request serialisation for writes. - * It is used to ensure that writes to the backing file of a backup process - * target cannot race with a read of the backup target that defers to the - * backing file. - * - * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to - * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be - * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long. - */ + /* Forces request serialisation. Use only with write requests. */ BDRV_REQ_SERIALISING = 0x80, /* Execute the request only if the operation can be offloaded or otherwise @@ -86,8 +77,15 @@ typedef enum { * written to qiov parameter which may be NULL. */ BDRV_REQ_PREFETCH = 0x200, + + /* + * If we need to wait for other requests, just fail immediately. Used + * only together with BDRV_REQ_SERIALISING. + */ + BDRV_REQ_NO_WAIT = 0x400, + /* Mask of valid flags */ - BDRV_REQ_MASK = 0x3ff, + BDRV_REQ_MASK = 0x7ff, } BdrvRequestFlags; typedef struct BlockSizes { diff --git a/include/block/block_int.h b/include/block/block_int.h index 1eeafc118c..b9ef61fe4d 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -1060,7 +1060,8 @@ 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); -bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); +bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req, + uint64_t align); BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs); int get_tmp_filename(char *filename, int size); diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 1b9e58e82b..df9ec08f8a 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -222,4 +222,15 @@ extern void QEMU_NORETURN QEMU_ERROR("code path is reachable") #define qemu_build_not_reached() g_assert_not_reached() #endif +/** + * In most cases, normal "fallthrough" comments are good enough for + * switch-case statements, but sometimes the compiler has problems + * with those. In that case you can use QEMU_FALLTHROUGH instead. + */ +#if __has_attribute(fallthrough) +# define QEMU_FALLTHROUGH __attribute__((fallthrough)) +#else +# define QEMU_FALLTHROUGH do {} while (0) /* fallthrough */ +#endif + #endif /* COMPILER_H */ |