From 83f6409109acd7cd13ff8a603f29c46033c4fb00 Mon Sep 17 00:00:00 2001 From: bellard Date: Tue, 1 Aug 2006 16:21:11 +0000 Subject: async file I/O API git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2075 c046a42c-6fe2-441c-8c8c-71466251a162 --- block-qcow.c | 368 ++++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 290 insertions(+), 78 deletions(-) (limited to 'block-qcow.c') diff --git a/block-qcow.c b/block-qcow.c index e5b52fb..65e74e7 100644 --- a/block-qcow.c +++ b/block-qcow.c @@ -1,7 +1,7 @@ /* * Block driver for the QCOW format * - * Copyright (c) 2004 Fabrice Bellard + * Copyright (c) 2004-2006 Fabrice Bellard * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal @@ -53,7 +53,7 @@ typedef struct QCowHeader { #define L2_CACHE_SIZE 16 typedef struct BDRVQcowState { - int fd; + BlockDriverState *hd; int cluster_bits; int cluster_size; int cluster_sectors; @@ -89,20 +89,16 @@ static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) return 0; } -static int qcow_open(BlockDriverState *bs, const char *filename) +static int qcow_open(BlockDriverState *bs, const char *filename, int flags) { BDRVQcowState *s = bs->opaque; - int fd, len, i, shift; + int len, i, shift, ret; QCowHeader header; - - fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE); - if (fd < 0) { - fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); - if (fd < 0) - return -1; - } - s->fd = fd; - if (read(fd, &header, sizeof(header)) != sizeof(header)) + + ret = bdrv_file_open(&s->hd, filename, flags); + if (ret < 0) + return ret; + if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) goto fail; be32_to_cpus(&header.magic); be32_to_cpus(&header.version); @@ -138,8 +134,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename) s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t)); if (!s->l1_table) goto fail; - lseek(fd, s->l1_table_offset, SEEK_SET); - if (read(fd, s->l1_table, s->l1_size * sizeof(uint64_t)) != + if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != s->l1_size * sizeof(uint64_t)) goto fail; for(i = 0;i < s->l1_size; i++) { @@ -162,8 +157,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename) len = header.backing_file_size; if (len > 1023) len = 1023; - lseek(fd, header.backing_file_offset, SEEK_SET); - if (read(fd, bs->backing_file, len) != len) + if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) goto fail; bs->backing_file[len] = '\0'; } @@ -174,7 +168,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename) qemu_free(s->l2_cache); qemu_free(s->cluster_cache); qemu_free(s->cluster_data); - close(fd); + bdrv_delete(s->hd); return -1; } @@ -276,14 +270,14 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, if (!allocate) return 0; /* allocate a new l2 entry */ - l2_offset = lseek(s->fd, 0, SEEK_END); + l2_offset = bdrv_getlength(s->hd); /* round to cluster size */ l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); /* update the L1 entry */ s->l1_table[l1_index] = l2_offset; tmp = cpu_to_be64(l2_offset); - lseek(s->fd, s->l1_table_offset + l1_index * sizeof(tmp), SEEK_SET); - if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) + if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), + &tmp, sizeof(tmp)) != sizeof(tmp)) return 0; new_l2_table = 1; } @@ -309,14 +303,13 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, } } l2_table = s->l2_cache + (min_index << s->l2_bits); - lseek(s->fd, l2_offset, SEEK_SET); if (new_l2_table) { memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); - if (write(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != + if (bdrv_pwrite(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != s->l2_size * sizeof(uint64_t)) return 0; } else { - if (read(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != + if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != s->l2_size * sizeof(uint64_t)) return 0; } @@ -337,21 +330,20 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, overwritten */ if (decompress_cluster(s, cluster_offset) < 0) return 0; - cluster_offset = lseek(s->fd, 0, SEEK_END); + cluster_offset = bdrv_getlength(s->hd); cluster_offset = (cluster_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); /* write the cluster content */ - lseek(s->fd, cluster_offset, SEEK_SET); - if (write(s->fd, s->cluster_cache, s->cluster_size) != + if (bdrv_pwrite(s->hd, cluster_offset, s->cluster_cache, s->cluster_size) != s->cluster_size) return -1; } else { - cluster_offset = lseek(s->fd, 0, SEEK_END); + cluster_offset = bdrv_getlength(s->hd); if (allocate == 1) { /* round to cluster size */ cluster_offset = (cluster_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); - ftruncate(s->fd, cluster_offset + s->cluster_size); + bdrv_truncate(s->hd, cluster_offset + s->cluster_size); /* if encrypted, we must initialize the cluster content which won't be written */ if (s->crypt_method && @@ -365,8 +357,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, s->cluster_data, s->cluster_data + 512, 1, 1, &s->aes_encrypt_key); - lseek(s->fd, cluster_offset + i * 512, SEEK_SET); - if (write(s->fd, s->cluster_data, 512) != 512) + if (bdrv_pwrite(s->hd, cluster_offset + i * 512, + s->cluster_data, 512) != 512) return -1; } } @@ -379,8 +371,8 @@ static uint64_t get_cluster_offset(BlockDriverState *bs, /* update L2 table */ tmp = cpu_to_be64(cluster_offset); l2_table[l2_index] = tmp; - lseek(s->fd, l2_offset + l2_index * sizeof(tmp), SEEK_SET); - if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) + if (bdrv_pwrite(s->hd, + l2_offset + l2_index * sizeof(tmp), &tmp, sizeof(tmp)) != sizeof(tmp)) return 0; } return cluster_offset; @@ -438,8 +430,7 @@ static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) if (s->cluster_cache_offset != coffset) { csize = cluster_offset >> (63 - s->cluster_bits); csize &= (s->cluster_size - 1); - lseek(s->fd, coffset, SEEK_SET); - ret = read(s->fd, s->cluster_data, csize); + ret = bdrv_pread(s->hd, coffset, s->cluster_data, csize); if (ret != csize) return -1; if (decompress_buffer(s->cluster_cache, s->cluster_size, @@ -451,6 +442,8 @@ static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) return 0; } +#if 0 + static int qcow_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { @@ -465,14 +458,20 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num, if (n > nb_sectors) n = nb_sectors; if (!cluster_offset) { - memset(buf, 0, 512 * n); + if (bs->backing_hd) { + /* read from the base image */ + ret = bdrv_read(bs->backing_hd, sector_num, buf, n); + if (ret < 0) + return -1; + } else { + memset(buf, 0, 512 * n); + } } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { if (decompress_cluster(s, cluster_offset) < 0) return -1; memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); } else { - lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET); - ret = read(s->fd, buf, n * 512); + ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); if (ret != n * 512) return -1; if (s->crypt_method) { @@ -486,6 +485,7 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num, } return 0; } +#endif static int qcow_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) @@ -504,13 +504,13 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num, index_in_cluster + n); if (!cluster_offset) return -1; - lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET); if (s->crypt_method) { encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1, &s->aes_encrypt_key); - ret = write(s->fd, s->cluster_data, n * 512); + ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, + s->cluster_data, n * 512); } else { - ret = write(s->fd, buf, n * 512); + ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); } if (ret != n * 512) return -1; @@ -522,6 +522,231 @@ static int qcow_write(BlockDriverState *bs, int64_t sector_num, return 0; } +typedef struct { + int64_t sector_num; + uint8_t *buf; + int nb_sectors; + int n; + uint64_t cluster_offset; + uint8_t *cluster_data; + BlockDriverAIOCB *hd_aiocb; + BlockDriverAIOCB *backing_hd_aiocb; +} QCowAIOCB; + +static void qcow_aio_delete(BlockDriverAIOCB *acb); + +static int qcow_aio_new(BlockDriverAIOCB *acb) +{ + BlockDriverState *bs = acb->bs; + BDRVQcowState *s = bs->opaque; + QCowAIOCB *acb1; + acb1 = qemu_mallocz(sizeof(QCowAIOCB)); + if (!acb1) + return -1; + acb->opaque = acb1; + acb1->hd_aiocb = bdrv_aio_new(s->hd); + if (!acb1->hd_aiocb) + goto fail; + if (bs->backing_hd) { + acb1->backing_hd_aiocb = bdrv_aio_new(bs->backing_hd); + if (!acb1->backing_hd_aiocb) + goto fail; + } + return 0; + fail: + qcow_aio_delete(acb); + return -1; +} + +static void qcow_aio_read_cb(void *opaque, int ret) +{ + BlockDriverAIOCB *acb = opaque; + BlockDriverState *bs = acb->bs; + BDRVQcowState *s = bs->opaque; + QCowAIOCB *acb1 = acb->opaque; + int index_in_cluster; + + if (ret < 0) { + fail: + acb->cb(acb->cb_opaque, ret); + return; + } + + redo: + /* post process the read buffer */ + if (!acb1->cluster_offset) { + /* nothing to do */ + } else if (acb1->cluster_offset & QCOW_OFLAG_COMPRESSED) { + /* nothing to do */ + } else { + if (s->crypt_method) { + encrypt_sectors(s, acb1->sector_num, acb1->buf, acb1->buf, + acb1->n, 0, + &s->aes_decrypt_key); + } + } + + acb1->nb_sectors -= acb1->n; + acb1->sector_num += acb1->n; + acb1->buf += acb1->n * 512; + + if (acb1->nb_sectors == 0) { + /* request completed */ + acb->cb(acb->cb_opaque, 0); + return; + } + + /* prepare next AIO request */ + acb1->cluster_offset = get_cluster_offset(bs, + acb1->sector_num << 9, + 0, 0, 0, 0); + index_in_cluster = acb1->sector_num & (s->cluster_sectors - 1); + acb1->n = s->cluster_sectors - index_in_cluster; + if (acb1->n > acb1->nb_sectors) + acb1->n = acb1->nb_sectors; + + if (!acb1->cluster_offset) { + if (bs->backing_hd) { + /* read from the base image */ + ret = bdrv_aio_read(acb1->backing_hd_aiocb, acb1->sector_num, + acb1->buf, acb1->n, qcow_aio_read_cb, acb); + if (ret < 0) + goto fail; + } else { + /* Note: in this case, no need to wait */ + memset(acb1->buf, 0, 512 * acb1->n); + goto redo; + } + } else if (acb1->cluster_offset & QCOW_OFLAG_COMPRESSED) { + /* add AIO support for compressed blocks ? */ + if (decompress_cluster(s, acb1->cluster_offset) < 0) + goto fail; + memcpy(acb1->buf, + s->cluster_cache + index_in_cluster * 512, 512 * acb1->n); + goto redo; + } else { + if ((acb1->cluster_offset & 511) != 0) { + ret = -EIO; + goto fail; + } + ret = bdrv_aio_read(acb1->hd_aiocb, + (acb1->cluster_offset >> 9) + index_in_cluster, + acb1->buf, acb1->n, qcow_aio_read_cb, acb); + if (ret < 0) + goto fail; + } +} + +static int qcow_aio_read(BlockDriverAIOCB *acb, int64_t sector_num, + uint8_t *buf, int nb_sectors) +{ + QCowAIOCB *acb1 = acb->opaque; + + acb1->sector_num = sector_num; + acb1->buf = buf; + acb1->nb_sectors = nb_sectors; + acb1->n = 0; + acb1->cluster_offset = 0; + + qcow_aio_read_cb(acb, 0); +} + +static void qcow_aio_write_cb(void *opaque, int ret) +{ + BlockDriverAIOCB *acb = opaque; + BlockDriverState *bs = acb->bs; + BDRVQcowState *s = bs->opaque; + QCowAIOCB *acb1 = acb->opaque; + int index_in_cluster; + uint64_t cluster_offset; + const uint8_t *src_buf; + + if (ret < 0) { + fail: + acb->cb(acb->cb_opaque, ret); + return; + } + + acb1->nb_sectors -= acb1->n; + acb1->sector_num += acb1->n; + acb1->buf += acb1->n * 512; + + if (acb1->nb_sectors == 0) { + /* request completed */ + acb->cb(acb->cb_opaque, 0); + return; + } + + index_in_cluster = acb1->sector_num & (s->cluster_sectors - 1); + acb1->n = s->cluster_sectors - index_in_cluster; + if (acb1->n > acb1->nb_sectors) + acb1->n = acb1->nb_sectors; + cluster_offset = get_cluster_offset(bs, acb1->sector_num << 9, 1, 0, + index_in_cluster, + index_in_cluster + acb1->n); + if (!cluster_offset || (cluster_offset & 511) != 0) { + ret = -EIO; + goto fail; + } + if (s->crypt_method) { + if (!acb1->cluster_data) { + acb1->cluster_data = qemu_mallocz(s->cluster_size); + if (!acb1->cluster_data) { + ret = -ENOMEM; + goto fail; + } + } + encrypt_sectors(s, acb1->sector_num, acb1->cluster_data, acb1->buf, + acb1->n, 1, &s->aes_encrypt_key); + src_buf = acb1->cluster_data; + } else { + src_buf = acb1->buf; + } + ret = bdrv_aio_write(acb1->hd_aiocb, + (cluster_offset >> 9) + index_in_cluster, + src_buf, acb1->n, + qcow_aio_write_cb, acb); + if (ret < 0) + goto fail; +} + +static int qcow_aio_write(BlockDriverAIOCB *acb, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + QCowAIOCB *acb1 = acb->opaque; + BlockDriverState *bs = acb->bs; + BDRVQcowState *s = bs->opaque; + + s->cluster_cache_offset = -1; /* disable compressed cache */ + + acb1->sector_num = sector_num; + acb1->buf = (uint8_t *)buf; + acb1->nb_sectors = nb_sectors; + acb1->n = 0; + + qcow_aio_write_cb(acb, 0); +} + +static void qcow_aio_cancel(BlockDriverAIOCB *acb) +{ + QCowAIOCB *acb1 = acb->opaque; + if (acb1->hd_aiocb) + bdrv_aio_cancel(acb1->hd_aiocb); + if (acb1->backing_hd_aiocb) + bdrv_aio_cancel(acb1->backing_hd_aiocb); +} + +static void qcow_aio_delete(BlockDriverAIOCB *acb) +{ + QCowAIOCB *acb1 = acb->opaque; + if (acb1->hd_aiocb) + bdrv_aio_delete(acb1->hd_aiocb); + if (acb1->backing_hd_aiocb) + bdrv_aio_delete(acb1->backing_hd_aiocb); + qemu_free(acb1->cluster_data); + qemu_free(acb1); +} + static void qcow_close(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; @@ -529,7 +754,7 @@ static void qcow_close(BlockDriverState *bs) qemu_free(s->l2_cache); qemu_free(s->cluster_cache); qemu_free(s->cluster_data); - close(s->fd); + bdrv_delete(s->hd); } static int qcow_create(const char *filename, int64_t total_size, @@ -537,12 +762,9 @@ static int qcow_create(const char *filename, int64_t total_size, { int fd, header_size, backing_filename_len, l1_size, i, shift; QCowHeader header; - char backing_filename[1024]; uint64_t tmp; - struct stat st; - fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, - 0644); + fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); if (fd < 0) return -1; memset(&header, 0, sizeof(header)); @@ -552,28 +774,11 @@ static int qcow_create(const char *filename, int64_t total_size, header_size = sizeof(header); backing_filename_len = 0; if (backing_file) { - if (strcmp(backing_file, "fat:")) { - const char *p; - /* XXX: this is a hack: we do not attempt to check for URL - like syntax */ - p = strchr(backing_file, ':'); - if (p && (p - backing_file) >= 2) { - /* URL like but exclude "c:" like filenames */ - pstrcpy(backing_filename, sizeof(backing_filename), - backing_file); - } else { - realpath(backing_file, backing_filename); - if (stat(backing_filename, &st) != 0) { - return -1; - } - } - header.backing_file_offset = cpu_to_be64(header_size); - backing_filename_len = strlen(backing_filename); - header.backing_file_size = cpu_to_be32(backing_filename_len); - header_size += backing_filename_len; - } else - backing_file = NULL; - header.mtime = cpu_to_be32(st.st_mtime); + header.backing_file_offset = cpu_to_be64(header_size); + backing_filename_len = strlen(backing_file); + header.backing_file_size = cpu_to_be32(backing_filename_len); + header_size += backing_filename_len; + header.mtime = cpu_to_be32(0); header.cluster_bits = 9; /* 512 byte cluster to avoid copying unmodifyed sectors */ header.l2_bits = 12; /* 32 KB L2 tables */ @@ -595,7 +800,7 @@ static int qcow_create(const char *filename, int64_t total_size, /* write all the data */ write(fd, &header, sizeof(header)); if (backing_file) { - write(fd, backing_filename, backing_filename_len); + write(fd, backing_file, backing_filename_len); } lseek(fd, header_size, SEEK_SET); tmp = 0; @@ -610,12 +815,14 @@ int qcow_make_empty(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; uint32_t l1_length = s->l1_size * sizeof(uint64_t); + int ret; memset(s->l1_table, 0, l1_length); - lseek(s->fd, s->l1_table_offset, SEEK_SET); - if (write(s->fd, s->l1_table, l1_length) < 0) + if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) return -1; - ftruncate(s->fd, s->l1_table_offset + l1_length); + ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); + if (ret < 0) + return ret; memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); @@ -682,8 +889,7 @@ int qcow_compress_cluster(BlockDriverState *bs, int64_t sector_num, cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, out_len, 0, 0); cluster_offset &= s->cluster_offset_mask; - lseek(s->fd, cluster_offset, SEEK_SET); - if (write(s->fd, out_buf, out_len) != out_len) { + if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) { qemu_free(out_buf); return -1; } @@ -696,7 +902,7 @@ int qcow_compress_cluster(BlockDriverState *bs, int64_t sector_num, static void qcow_flush(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; - fsync(s->fd); + bdrv_flush(s->hd); } BlockDriver bdrv_qcow = { @@ -704,14 +910,20 @@ BlockDriver bdrv_qcow = { sizeof(BDRVQcowState), qcow_probe, qcow_open, - qcow_read, - qcow_write, + NULL, + NULL, qcow_close, qcow_create, qcow_flush, qcow_is_allocated, qcow_set_key, - qcow_make_empty + qcow_make_empty, + + .bdrv_aio_new = qcow_aio_new, + .bdrv_aio_read = qcow_aio_read, + .bdrv_aio_write = qcow_aio_write, + .bdrv_aio_cancel = qcow_aio_cancel, + .bdrv_aio_delete = qcow_aio_delete, }; -- cgit v1.1