diff options
| -rw-r--r-- | block/raw-posix.c | 49 | ||||
| -rw-r--r-- | block/vpc.c | 14 |
2 files changed, 53 insertions, 10 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c index 8b6b92608b..4dfdf985b0 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -1257,9 +1257,43 @@ static int hdev_probe_device(const char *filename) return 0; } +static int check_hdev_writable(BDRVRawState *s) +{ +#if defined(BLKROGET) + /* Linux block devices can be configured "read-only" using blockdev(8). + * This is independent of device node permissions and therefore open(2) + * with O_RDWR succeeds. Actual writes fail with EPERM. + * + * bdrv_open() is supposed to fail if the disk is read-only. Explicitly + * check for read-only block devices so that Linux block devices behave + * properly. + */ + struct stat st; + int readonly = 0; + + if (fstat(s->fd, &st)) { + return -errno; + } + + if (!S_ISBLK(st.st_mode)) { + return 0; + } + + if (ioctl(s->fd, BLKROGET, &readonly) < 0) { + return -errno; + } + + if (readonly) { + return -EACCES; + } +#endif /* defined(BLKROGET) */ + return 0; +} + static int hdev_open(BlockDriverState *bs, const char *filename, int flags) { BDRVRawState *s = bs->opaque; + int ret; #if defined(__APPLE__) && defined(__MACH__) if (strstart(filename, "/dev/cdrom", NULL)) { @@ -1300,7 +1334,20 @@ static int hdev_open(BlockDriverState *bs, const char *filename, int flags) } #endif - return raw_open_common(bs, filename, flags, 0); + ret = raw_open_common(bs, filename, flags, 0); + if (ret < 0) { + return ret; + } + + if (flags & BDRV_O_RDWR) { + ret = check_hdev_writable(s); + if (ret < 0) { + raw_close(bs); + return ret; + } + } + + return ret; } #if defined(__linux__) diff --git a/block/vpc.c b/block/vpc.c index b4ff5646a2..82229ef5a0 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -34,8 +34,6 @@ #define HEADER_SIZE 512 -#define VHD_SECTOR_SIZE 512 - //#define CACHE enum vhd_type { @@ -206,13 +204,11 @@ static int vpc_open(BlockDriverState *bs, int flags) /* Write 'checksum' back to footer, or else will leave it with zero. */ footer->checksum = be32_to_cpu(checksum); - /* The visible size of a image in Virtual PC depends on the guest: - * QEMU and other emulators report the real size (here in sectors). - * All modern operating systems use this real size. - * Very old operating systems use CHS values to calculate the total size. - * This calculated size is usually smaller than the real size. - */ - bs->total_sectors = be64_to_cpu(footer->size) / VHD_SECTOR_SIZE; + // The visible size of a image in Virtual PC depends on the geometry + // rather than on the size stored in the footer (the size in the footer + // is too large usually) + bs->total_sectors = (int64_t) + be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl; /* Allow a maximum disk size of approximately 2 TB */ if (bs->total_sectors >= 65535LL * 255 * 255) { |