diff options
Diffstat (limited to 'block-cow.c')
| -rw-r--r-- | block-cow.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/block-cow.c b/block-cow.c index 6af8b7497..07c8a7bf1 100644 --- a/block-cow.c +++ b/block-cow.c @@ -62,7 +62,7 @@ static int cow_probe(const uint8_t *buf, int buf_size, const char *filename) return 0; } -static int cow_open(BlockDriverState *bs, const char *filename) +static int cow_open(BlockDriverState *bs, const char *filename, int flags) { BDRVCowState *s = bs->opaque; int fd; @@ -93,22 +93,6 @@ static int cow_open(BlockDriverState *bs, const char *filename) pstrcpy(bs->backing_file, sizeof(bs->backing_file), cow_header.backing_file); -#if 0 - if (cow_header.backing_file[0] != '\0') { - if (stat(cow_header.backing_file, &st) != 0) { - fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file); - goto fail; - } - if (st.st_mtime != be32_to_cpu(cow_header.mtime)) { - fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file); - goto fail; - } - fd = open(cow_header.backing_file, O_RDONLY | O_LARGEFILE); - if (fd < 0) - goto fail; - bs->fd = fd; - } -#endif /* mmap the bitmap */ s->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header); s->cow_bitmap_addr = mmap(get_mmap_addr(s->cow_bitmap_size), @@ -179,8 +163,15 @@ static int cow_read(BlockDriverState *bs, int64_t sector_num, if (ret != n * 512) return -1; } else { + 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, n * 512); } + } nb_sectors -= n; sector_num += n; buf += n * 512; @@ -220,7 +211,7 @@ static int cow_create(const char *filename, int64_t image_sectors, if (flags) return -ENOTSUP; - cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, + cow_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); if (cow_fd < 0) return -1; @@ -228,18 +219,23 @@ static int cow_create(const char *filename, int64_t image_sectors, cow_header.magic = cpu_to_be32(COW_MAGIC); cow_header.version = cpu_to_be32(COW_VERSION); if (image_filename) { + /* Note: if no file, we put a dummy mtime */ + cow_header.mtime = cpu_to_be32(0); + fd = open(image_filename, O_RDONLY | O_BINARY); if (fd < 0) { close(cow_fd); - return -1; + goto mtime_fail; } if (fstat(fd, &st) != 0) { close(fd); - return -1; + goto mtime_fail; } close(fd); cow_header.mtime = cpu_to_be32(st.st_mtime); - realpath(image_filename, cow_header.backing_file); + mtime_fail: + pstrcpy(cow_header.backing_file, sizeof(cow_header.backing_file), + image_filename); } cow_header.sectorsize = cpu_to_be32(512); cow_header.size = cpu_to_be64(image_sectors * 512); |