/* * Block protocol for block driver correctness testing * * Copyright (C) 2010 IBM, Corp. * * 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 <stdarg.h> #include "qemu_socket.h" /* for EINPROGRESS on Windows */ #include "block_int.h" typedef struct { BlockDriverState *test_file; } BDRVBlkverifyState; typedef struct BlkverifyAIOCB BlkverifyAIOCB; struct BlkverifyAIOCB { BlockDriverAIOCB common; QEMUBH *bh; /* Request metadata */ bool is_write; int64_t sector_num; int nb_sectors; int ret; /* first completed request's result */ unsigned int done; /* completion counter */ bool *finished; /* completion signal for cancel */ QEMUIOVector *qiov; /* user I/O vector */ QEMUIOVector raw_qiov; /* cloned I/O vector for raw file */ void *buf; /* buffer for raw file I/O */ void (*verify)(BlkverifyAIOCB *acb); }; static void blkverify_aio_cancel(BlockDriverAIOCB *blockacb) { BlkverifyAIOCB *acb = (BlkverifyAIOCB *)blockacb; bool finished = false; /* Wait until request completes, invokes its callback, and frees itself */ acb->finished = &finished; while (!finished) { qemu_aio_wait(); } } static AIOPool blkverify_aio_pool = { .aiocb_size = sizeof(BlkverifyAIOCB), .cancel = blkverify_aio_cancel, }; static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyAIOCB *acb, const char *fmt, ...) { va_list ap; va_start(ap, fmt); fprintf(stderr, "blkverify: %s sector_num=%" PRId64 " nb_sectors=%d ", acb->is_write ? "write" : "read", acb->sector_num, acb->nb_sectors); vfprintf(stderr, fmt, ap); fprintf(stderr, "\n"); va_end(ap); exit(1); } /* Valid blkverify filenames look like blkverify:path/to/raw_image:path/to/image */ static int blkverify_open(BlockDriverState *bs, const char *filename, int flags) { BDRVBlkverifyState *s = bs->opaque; int ret; char *raw, *c; /* Parse the blkverify: prefix */ if (strncmp(filename, "blkverify:", strlen("blkverify:"))) { return -EINVAL; } filename += strlen("blkverify:"); /* Parse the raw image filename */ c = strchr(filename, ':'); if (c == NULL) { return -EINVAL; } raw = strdup(filename); raw[c - filename] = '\0'; ret = bdrv_file_open(&bs->file, raw, flags); free(raw); if (ret < 0) { return ret; } filename = c + 1; /* Open the test file */ s->test_file = bdrv_new(""); ret = bdrv_open(s->test_file, filename, flags, NULL); if (ret < 0) { bdrv_delete(s->test_file); s->test_file = NULL; return ret; } return 0; } static void blkverify_close(BlockDriverState *bs) { BDRVBlkverifyState *s = bs->opaque; bdrv_delete(s->test_file); s->test_file = NULL; } static int64_t blkverify_getlength(BlockDriverState *bs) { BDRVBlkverifyState *s = bs->opaque; return bdrv_getlength(s->test_file); } /** * Check that I/O vector contents are identical * * @a: I/O vector * @b: I/O vector * @ret: Offset to first mismatching byte or -1 if match */ static ssize_t blkverify_iovec_compare(QEMUIOVector *a, QEMUIOVector *b) { int i; ssize_t offset = 0; assert(a->niov == b->niov); for (i = 0; i < a->niov; i++) { size_t len = 0; uint8_t *p = (uint8_t *)a->iov[i].iov_base; uint8_t *q = (uint8_t *)b->iov[i].iov_base; assert(a->iov[i].iov_len == b->iov[i].iov_len); while (len < a->iov[i].iov_len && *p++ == *q++) { len++; } offset += len; if (len != a->iov[i].iov_len) { return offset; } } return -1; } typedef struct { int src_index; struct iovec *src_iov; void *dest_base; } IOVectorSortElem; static int sortelem_cmp_src_base(const void *a, const void *b) { const IOVectorSortElem *elem_a = a; const IOVectorSortElem *elem_b = b; /* Don't overflow */ if (elem_a->src_iov->iov_base < elem_b->src_iov->iov_base) { return -1; } else if (elem_a->src_iov->iov_base > elem_b->src_iov->iov_base) { return 1; } else { return 0; } } static int sortelem_cmp_src_index(const void *a, const void *b) { const IOVectorSortElem *elem_a = a; const IOVectorSortElem *elem_b = b; return elem_a->src_index - elem_b->src_index; } /** * Copy contents of I/O vector * * The relative relationships of overlapping iovecs are preserved. This is * necessary to ensure identical semantics in the cloned I/O vector. */ static void blkverify_iovec_clone(QEMUIOVector *dest, const QEMUIOVector *src, void *buf) { IOVectorSortElem sortelems[src->niov]; void *last_end; int i; /* Sort by source iovecs by base address */ for (i = 0; i < src->niov; i++) { sortelems[i].src_index = i; sortelems[i].src_iov = &src->iov[i]; } qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_base); /* Allocate buffer space taking into account overlapping iovecs */ last_end = NULL; for (i = 0; i < src->niov; i++) { struct iovec *cur = sortelems[i].src_iov; ptrdiff_t rewind = 0; /* Detect overlap */ if (last_end && last_end > cur->iov_base) { rewind = last_end - cur->iov_base; } sortelems[i].dest_base = buf - rewind; buf += cur->iov_len - MIN(rewind, cur->iov_len); last_end = MAX(cur->iov_base + cur->iov_len, last_end); } /* Sort by source iovec index and build destination iovec */ qsort(sortelems, src->niov, sizeof(sortelems[0]), sortelem_cmp_src_index); for (i = 0; i < src->niov; i++) { qemu_iovec_add(dest, sortelems[i].dest_base, src->iov[i].iov_len); } } static BlkverifyAIOCB *blkverify_aio_get(BlockDriverState *bs, bool is_write, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { BlkverifyAIOCB *acb = qemu_aio_get(&blkverify_aio_pool, bs, cb, opaque); acb->bh = NULL; acb->is_write = is_write; acb->sector_num = sector_num; acb->nb_sectors = nb_sectors; acb->ret = -EINPROGRESS; acb->done = 0; acb->qiov = qiov; acb->buf = NULL; acb->verify = NULL; acb->finished = NULL; return acb; } static void blkverify_aio_bh(void *opaque) { BlkverifyAIOCB *acb = opaque; qemu_bh_delete(acb->bh); if (acb->buf) { qemu_iovec_destroy(&acb->raw_qiov); qemu_vfree(acb->buf); } acb->common.cb(acb->common.opaque, acb->ret); if (acb->finished) { *acb->finished = true; } qemu_aio_release(acb); } static void blkverify_aio_cb(void *opaque, int ret) { BlkverifyAIOCB *acb = opaque; switch (++acb->done) { case 1: acb->ret = ret; break; case 2: if (acb->ret != ret) { blkverify_err(acb, "return value mismatch %d != %d", acb->ret, ret); } if (acb->verify) { acb->verify(acb); } acb->bh = qemu_bh_new(blkverify_aio_bh, acb); qemu_bh_schedule(acb->bh); break; } } static void blkverify_verify_readv(BlkverifyAIOCB *acb) { ssize_t offset = blkverify_iovec_compare(acb->qiov, &acb->raw_qiov); if (offset != -1) { blkverify_err(acb, "contents mismatch in sector %" PRId64, acb->sector_num + (int64_t)(offset / BDRV_SECTOR_SIZE)); } } static BlockDriverAIOCB *blkverify_aio_readv(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { BDRVBlkverifyState *s = bs->opaque; BlkverifyAIOCB *acb = blkverify_aio_get(bs, false, sector_num, qiov, nb_sectors, cb, opaque); acb->verify = blkverify_verify_readv; acb->buf = qemu_blockalign(bs->file, qiov->size); qemu_iovec_init(&acb->raw_qiov, acb->qiov->niov); blkverify_iovec_clone(&acb->raw_qiov, qiov, acb->buf); bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors, blkverify_aio_cb, acb); bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors, blkverify_aio_cb, acb); return &acb->common; } static BlockDriverAIOCB *blkverify_aio_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { BDRVBlkverifyState *s = bs->opaque; BlkverifyAIOCB *acb = blkverify_aio_get(bs, true, sector_num, qiov, nb_sectors, cb, opaque); bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors, blkverify_aio_cb, acb); bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, blkverify_aio_cb, acb); return &acb->common; } static BlockDriverAIOCB *blkverify_aio_flush(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque) { BDRVBlkverifyState *s = bs->opaque; /* Only flush test file, the raw file is not important */ return bdrv_aio_flush(s->test_file, cb, opaque); } static BlockDriver bdrv_blkverify = { .format_name = "blkverify", .protocol_name = "blkverify", .instance_size = sizeof(BDRVBlkverifyState), .bdrv_getlength = blkverify_getlength, .bdrv_file_open = blkverify_open, .bdrv_close = blkverify_close, .bdrv_aio_readv = blkverify_aio_readv, .bdrv_aio_writev = blkverify_aio_writev, .bdrv_aio_flush = blkverify_aio_flush, }; static void bdrv_blkverify_init(void) { bdrv_register(&bdrv_blkverify); } block_init(bdrv_blkverify_init);