OpenE2K/qemu-e2k
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block-vpc: Don't silently create smaller image than requested

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The algorithm from the VHD specification for CHS calculation silently limits
images to 127 GB which may confuse a user who requested a larger image. Better
output an error message and abort.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7109 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aurel32 2009-04-15 14:42:46 +00:00
parent 29463b24a8
commit 6e9ea0c062
2 changed files with 12 additions and 3 deletions
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11
block-vpc.c
View File

@ -433,14 +433,16 @@ static int vpc_write(BlockDriverState *bs, int64_t sector_num,
*
* Note that the geometry doesn't always exactly match total_sectors but
* may round it down.
*
* Returns 0 on success, -EFBIG if the size is larger than 127 GB
*/
static void calculate_geometry(int64_t total_sectors, uint16_t* cyls,
static int calculate_geometry(int64_t total_sectors, uint16_t* cyls,
uint8_t* heads, uint8_t* secs_per_cyl)
{
uint32_t cyls_times_heads;
if (total_sectors > 65535 * 16 * 255)
total_sectors = 65535 * 16 * 255;
return -EFBIG;
if (total_sectors > 65535 * 16 * 63) {
*secs_per_cyl = 255;
@ -470,6 +472,8 @@ static void calculate_geometry(int64_t total_sectors, uint16_t* cyls,
// Note: Rounding up deviates from the Virtual PC behaviour
// However, we need this to avoid truncating images in qemu-img convert
*cyls = (cyls_times_heads + *heads - 1) / *heads;
return 0;
}
static int vpc_create(const char *filename, int64_t total_sectors,
@ -493,7 +497,8 @@ static int vpc_create(const char *filename, int64_t total_sectors,
return -EIO;
// Calculate matching total_size and geometry
calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl);
if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl))
return -EFBIG;
total_sectors = (int64_t) cyls * heads * secs_per_cyl;
// Prepare the Hard Disk Footer

4
qemu-img.c
View File

@ -306,6 +306,8 @@ static int img_create(int argc, char **argv)
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting or formatting option not supported for file format '%s'", fmt);
} else if (ret == -EFBIG) {
error("The image size is too large for file format '%s'", fmt);
} else {
error("Error while formatting");
}
@ -494,6 +496,8 @@ static int img_convert(int argc, char **argv)
if (ret < 0) {
if (ret == -ENOTSUP) {
error("Formatting not supported for file format '%s'", out_fmt);
} else if (ret == -EFBIG) {
error("The image size is too large for file format '%s'", out_fmt);
} else {
error("Error while formatting '%s'", out_filename);
}