projects / mirror_qemu.git / blame
| Commit | Line | Data |
|---|---|---|
| d088e6a4 VSO |
1 | /* |
| 2 | * reqlist API | |
| 3 | * | |
| 4 | * Copyright (C) 2013 Proxmox Server Solutions | |
| 5 | * Copyright (c) 2021 Virtuozzo International GmbH. | |
| 6 | * | |
| 7 | * Authors: | |
| 8 | * Dietmar Maurer (dietmar@proxmox.com) | |
| 9 | * Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | |
| 10 | * | |
| 11 | * This work is licensed under the terms of the GNU GPL, version 2 or later. | |
| 12 | * See the COPYING file in the top-level directory. | |
| 13 | */ | |
| 14 | ||
| 15 | #ifndef REQLIST_H | |
| 16 | #define REQLIST_H | |
| 17 | ||
| 18 | #include "qemu/coroutine.h" | |
| 19 | ||
| 20 | /* | |
| 21 | * The API is not thread-safe and shouldn't be. The struct is public to be part | |
| 22 | * of other structures and protected by third-party locks, see | |
| 23 | * block/block-copy.c for example. | |
| 24 | */ | |
| 25 | ||
| 26 | typedef struct BlockReq { | |
| 27 | int64_t offset; | |
| 28 | int64_t bytes; | |
| 29 | ||
| 30 | CoQueue wait_queue; /* coroutines blocked on this req */ | |
| 31 | QLIST_ENTRY(BlockReq) list; | |
| 32 | } BlockReq; | |
| 33 | ||
| 34 | typedef QLIST_HEAD(, BlockReq) BlockReqList; | |
| 35 | ||
| 36 | /* | |
| 37 | * Initialize new request and add it to the list. Caller must be sure that | |
| 38 | * there are no conflicting requests in the list. | |
| 39 | */ | |
| 40 | void reqlist_init_req(BlockReqList *reqs, BlockReq *req, int64_t offset, | |
| 41 | int64_t bytes); | |
| 42 | /* Search for request in the list intersecting with @offset/@bytes area. */ | |
| 43 | BlockReq *reqlist_find_conflict(BlockReqList *reqs, int64_t offset, | |
| 44 | int64_t bytes); | |
| 45 | ||
| 46 | /* | |
| 47 | * If there are no intersecting requests return false. Otherwise, wait for the | |
| 48 | * first found intersecting request to finish and return true. | |
| 49 | * | |
| 50 | * @lock is passed to qemu_co_queue_wait() | |
| 51 | * False return value proves that lock was released at no point. | |
| 52 | */ | |
| 53 | bool coroutine_fn reqlist_wait_one(BlockReqList *reqs, int64_t offset, | |
| 54 | int64_t bytes, CoMutex *lock); | |
| 55 | ||
| 3b7ca26b VSO |
56 | /* |
| 57 | * Wait for all intersecting requests. It just calls reqlist_wait_one() in a | |
| 58 | * loop, caller is responsible to stop producing new requests in this region | |
| 59 | * in parallel, otherwise reqlist_wait_all() may never return. | |
| 60 | */ | |
| 61 | void coroutine_fn reqlist_wait_all(BlockReqList *reqs, int64_t offset, | |
| 62 | int64_t bytes, CoMutex *lock); | |
| 63 | ||
| d088e6a4 VSO |
64 | /* |
| 65 | * Shrink request and wake all waiting coroutines (maybe some of them are not | |
| 66 | * intersecting with shrunk request). | |
| 67 | */ | |
| 68 | void coroutine_fn reqlist_shrink_req(BlockReq *req, int64_t new_bytes); | |
| 69 | ||
| 70 | /* | |
| 71 | * Remove request and wake all waiting coroutines. Do not release any memory. | |
| 72 | */ | |
| 73 | void coroutine_fn reqlist_remove_req(BlockReq *req); | |
| 74 | ||
| 75 | #endif /* REQLIST_H */ |