1 #include "kvm/disk-image.h" 2 3 static ssize_t raw_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount) 4 { 5 u64 offset = sector << SECTOR_SHIFT; 6 7 return preadv_in_full(disk->fd, iov, iovcount, offset); 8 } 9 10 static ssize_t raw_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount) 11 { 12 u64 offset = sector << SECTOR_SHIFT; 13 14 return pwritev_in_full(disk->fd, iov, iovcount, offset); 15 } 16 17 static int raw_image__read_sector_ro_mmap(struct disk_image *disk, u64 sector, void *dst, u32 dst_len) 18 { 19 u64 offset = sector << SECTOR_SHIFT; 20 21 if (offset + dst_len > disk->size) 22 return -1; 23 24 memcpy(dst, disk->priv + offset, dst_len); 25 26 return 0; 27 } 28 29 static int raw_image__write_sector_ro_mmap(struct disk_image *disk, u64 sector, void *src, u32 src_len) 30 { 31 u64 offset = sector << SECTOR_SHIFT; 32 33 if (offset + src_len > disk->size) 34 return -1; 35 36 memcpy(disk->priv + offset, src, src_len); 37 38 return 0; 39 } 40 41 static void raw_image__close_ro_mmap(struct disk_image *disk) 42 { 43 if (disk->priv != MAP_FAILED) 44 munmap(disk->priv, disk->size); 45 } 46 47 static struct disk_image_operations raw_image_ops = { 48 .read_sector_iov = raw_image__read_sector_iov, 49 .write_sector_iov = raw_image__write_sector_iov 50 }; 51 52 static struct disk_image_operations raw_image_ro_mmap_ops = { 53 .read_sector = raw_image__read_sector_ro_mmap, 54 .write_sector = raw_image__write_sector_ro_mmap, 55 .close = raw_image__close_ro_mmap, 56 }; 57 58 struct disk_image *raw_image__probe(int fd, struct stat *st, bool readonly) 59 { 60 61 if (readonly) 62 /* 63 * Use mmap's MAP_PRIVATE to implement non-persistent write 64 * FIXME: This does not work on 32-bit host. 65 */ 66 return disk_image__new(fd, st->st_size, &raw_image_ro_mmap_ops, DISK_IMAGE_MMAP); 67 else 68 /* 69 * Use read/write instead of mmap 70 */ 71 return disk_image__new(fd, st->st_size, &raw_image_ops, DISK_IMAGE_NOMMAP); 72 } 73 74 struct disk_image *blkdev__probe(const char *filename, struct stat *st) 75 { 76 u64 size; 77 int fd; 78 79 if (!S_ISBLK(st->st_mode)) 80 return NULL; 81 82 fd = open(filename, O_RDONLY); 83 if (fd < 0) 84 return NULL; 85 86 if (ioctl(fd, BLKGETSIZE64, &size) < 0) { 87 close(fd); 88 return NULL; 89 } 90 91 return disk_image__new(fd, size, &raw_image_ro_mmap_ops, DISK_IMAGE_MMAP); 92 } 93