#include "kvm/disk-image.h" #include "kvm/read-write.h" #include "kvm/qcow.h" #include "kvm/util.h" #include /* for BLKGETSIZE64 */ #include #include #include #include #include #include #include #include #include #include struct disk_image *disk_image__new(int fd, u64 size, struct disk_image_operations *ops) { struct disk_image *disk; disk = malloc(sizeof *disk); if (!disk) return NULL; disk->fd = fd; disk->size = size; disk->ops = ops; return disk; } struct disk_image *disk_image__new_readonly(int fd, u64 size, struct disk_image_operations *ops) { struct disk_image *disk; disk = disk_image__new(fd, size, ops); if (!disk) return NULL; disk->priv = mmap(NULL, size, PROT_RW, MAP_PRIVATE | MAP_NORESERVE, fd, 0); if (disk->priv == MAP_FAILED) die("mmap() failed"); return disk; } static ssize_t raw_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount) { u64 offset = sector << SECTOR_SHIFT; return preadv_in_full(disk->fd, iov, iovcount, offset); } static ssize_t raw_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount) { u64 offset = sector << SECTOR_SHIFT; return pwritev_in_full(disk->fd, iov, iovcount, offset); } static int raw_image__read_sector_ro_mmap(struct disk_image *disk, u64 sector, void *dst, u32 dst_len) { u64 offset = sector << SECTOR_SHIFT; if (offset + dst_len > disk->size) return -1; memcpy(dst, disk->priv + offset, dst_len); return 0; } static int raw_image__write_sector_ro_mmap(struct disk_image *disk, u64 sector, void *src, u32 src_len) { u64 offset = sector << SECTOR_SHIFT; if (offset + src_len > disk->size) return -1; memcpy(disk->priv + offset, src, src_len); return 0; } static void raw_image__close_ro_mmap(struct disk_image *disk) { if (disk->priv != MAP_FAILED) munmap(disk->priv, disk->size); } static struct disk_image_operations raw_image_ops = { .read_sector_iov = raw_image__read_sector_iov, .write_sector_iov = raw_image__write_sector_iov }; static struct disk_image_operations raw_image_ro_mmap_ops = { .read_sector = raw_image__read_sector_ro_mmap, .write_sector = raw_image__write_sector_ro_mmap, .close = raw_image__close_ro_mmap, }; static struct disk_image *raw_image__probe(int fd, struct stat *st, bool readonly) { if (readonly) return disk_image__new_readonly(fd, st->st_size, &raw_image_ro_mmap_ops); else return disk_image__new(fd, st->st_size, &raw_image_ops); } static struct disk_image *blkdev__probe(const char *filename, struct stat *st) { u64 size; int fd; if (!S_ISBLK(st->st_mode)) return NULL; fd = open(filename, O_RDONLY); if (fd < 0) return NULL; if (ioctl(fd, BLKGETSIZE64, &size) < 0) { close(fd); return NULL; } return disk_image__new_readonly(fd, size, &raw_image_ro_mmap_ops); } struct disk_image *disk_image__open(const char *filename, bool readonly) { struct disk_image *disk; struct stat st; int fd; if (stat(filename, &st) < 0) return NULL; if (S_ISBLK(st.st_mode)) return blkdev__probe(filename, &st); fd = open(filename, readonly ? O_RDONLY : O_RDWR); if (fd < 0) return NULL; disk = qcow_probe(fd); if (disk) return disk; disk = raw_image__probe(fd, &st, readonly); if (disk) return disk; if (close(fd) < 0) warning("close() failed"); return NULL; } void disk_image__close(struct disk_image *disk) { /* If there was no disk image then there's nothing to do: */ if (!disk) return; if (disk->ops->close) disk->ops->close(disk); if (close(disk->fd) < 0) warning("close() failed"); free(disk); }