diff options
Diffstat (limited to 'block/blkreplay.c')
| -rw-r--r-- | block/blkreplay.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/block/blkreplay.c b/block/blkreplay.c new file mode 100644 index 000000000..dcbe780dd --- /dev/null +++ b/block/blkreplay.c @@ -0,0 +1,158 @@ +/* + * Block protocol for record/replay + * + * Copyright (c) 2010-2016 Institute for System Programming + * of the Russian Academy of Sciences. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "qemu/module.h" +#include "block/block_int.h" +#include "sysemu/replay.h" +#include "qapi/error.h" + +typedef struct Request { + Coroutine *co; + QEMUBH *bh; +} Request; + +static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + int ret; + + /* Open the image file */ + bs->file = bdrv_open_child(NULL, options, "image", bs, &child_of_bds, + BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY, + false, errp); + if (!bs->file) { + ret = -EINVAL; + goto fail; + } + + bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED; + bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED; + + ret = 0; +fail: + return ret; +} + +static int64_t blkreplay_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + +/* This bh is used for synchronization of return from coroutines. + It continues yielded coroutine which then finishes its execution. + BH is called adjusted to some replay checkpoint, therefore + record and replay will always finish coroutines deterministically. +*/ +static void blkreplay_bh_cb(void *opaque) +{ + Request *req = opaque; + aio_co_wake(req->co); + qemu_bh_delete(req->bh); + g_free(req); +} + +static void block_request_create(uint64_t reqid, BlockDriverState *bs, + Coroutine *co) +{ + Request *req = g_new(Request, 1); + *req = (Request) { + .co = co, + .bh = aio_bh_new(bdrv_get_aio_context(bs), blkreplay_bh_cb, req), + }; + replay_block_event(req->bh, reqid); +} + +static int coroutine_fn blkreplay_co_preadv(BlockDriverState *bs, + int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) +{ + uint64_t reqid = blkreplay_next_id(); + int ret = bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_pwritev(BlockDriverState *bs, + int64_t offset, int64_t bytes, QEMUIOVector *qiov, BdrvRequestFlags flags) +{ + uint64_t reqid = blkreplay_next_id(); + int ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_pwrite_zeroes(BlockDriverState *bs, + int64_t offset, int64_t bytes, BdrvRequestFlags flags) +{ + uint64_t reqid = blkreplay_next_id(); + int ret = bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_pdiscard(BlockDriverState *bs, + int64_t offset, int64_t bytes) +{ + uint64_t reqid = blkreplay_next_id(); + int ret = bdrv_co_pdiscard(bs->file, offset, bytes); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs) +{ + uint64_t reqid = blkreplay_next_id(); + int ret = bdrv_co_flush(bs->file->bs); + block_request_create(reqid, bs, qemu_coroutine_self()); + qemu_coroutine_yield(); + + return ret; +} + +static int blkreplay_snapshot_goto(BlockDriverState *bs, + const char *snapshot_id) +{ + return bdrv_snapshot_goto(bs->file->bs, snapshot_id, NULL); +} + +static BlockDriver bdrv_blkreplay = { + .format_name = "blkreplay", + .instance_size = 0, + .is_filter = true, + + .bdrv_open = blkreplay_open, + .bdrv_child_perm = bdrv_default_perms, + .bdrv_getlength = blkreplay_getlength, + + .bdrv_co_preadv = blkreplay_co_preadv, + .bdrv_co_pwritev = blkreplay_co_pwritev, + + .bdrv_co_pwrite_zeroes = blkreplay_co_pwrite_zeroes, + .bdrv_co_pdiscard = blkreplay_co_pdiscard, + .bdrv_co_flush = blkreplay_co_flush, + + .bdrv_snapshot_goto = blkreplay_snapshot_goto, +}; + +static void bdrv_blkreplay_init(void) +{ + bdrv_register(&bdrv_blkreplay); +} + +block_init(bdrv_blkreplay_init); |