gwj / at91sam9263 · Commits

Commit 6e9ea0c0629fe25723494a19498bedf4b781cbfa

Authored by aurel32
1 parent 29463b24

block-vpc: Don't silently create smaller image than requested 

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
Inline Side-by-side
Showing 2 changed files with 12 additions and 3 deletions
block-vpc.c
  View file @6e9ea0c
@@ -433,14 +433,16 @@ static int vpc_write(BlockDriverState *bs, int64_t sector_num, @@ -433,14 +433,16 @@ static int vpc_write(BlockDriverState *bs, int64_t sector_num,
433 * 433 *
434 * Note that the geometry doesn't always exactly match total_sectors but 434 * Note that the geometry doesn't always exactly match total_sectors but
435 * may round it down. 435 * may round it down.
  436 + *
  437 + * Returns 0 on success, -EFBIG if the size is larger than 127 GB
436 */ 438 */
437 -static void calculate_geometry(int64_t total_sectors, uint16_t* cyls, 439 +static int calculate_geometry(int64_t total_sectors, uint16_t* cyls,
438 uint8_t* heads, uint8_t* secs_per_cyl) 440 uint8_t* heads, uint8_t* secs_per_cyl)
439 { 441 {
440 uint32_t cyls_times_heads; 442 uint32_t cyls_times_heads;
441 443
442 if (total_sectors > 65535 * 16 * 255) 444 if (total_sectors > 65535 * 16 * 255)
443 - total_sectors = 65535 * 16 * 255; 445 + return -EFBIG;
444 446
445 if (total_sectors > 65535 * 16 * 63) { 447 if (total_sectors > 65535 * 16 * 63) {
446 *secs_per_cyl = 255; 448 *secs_per_cyl = 255;
@@ -470,6 +472,8 @@ static void calculate_geometry(int64_t total_sectors, uint16_t* cyls, @@ -470,6 +472,8 @@ static void calculate_geometry(int64_t total_sectors, uint16_t* cyls,
470 // Note: Rounding up deviates from the Virtual PC behaviour 472 // Note: Rounding up deviates from the Virtual PC behaviour
471 // However, we need this to avoid truncating images in qemu-img convert 473 // However, we need this to avoid truncating images in qemu-img convert
472 *cyls = (cyls_times_heads + *heads - 1) / *heads; 474 *cyls = (cyls_times_heads + *heads - 1) / *heads;
  475 +
  476 + return 0;
473 } 477 }
474 478
475 static int vpc_create(const char *filename, int64_t total_sectors, 479 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, @@ -493,7 +497,8 @@ static int vpc_create(const char *filename, int64_t total_sectors,
493 return -EIO; 497 return -EIO;
494 498
495 // Calculate matching total_size and geometry 499 // Calculate matching total_size and geometry
496 - calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl); 500 + if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl))
  501 + return -EFBIG;
497 total_sectors = (int64_t) cyls * heads * secs_per_cyl; 502 total_sectors = (int64_t) cyls * heads * secs_per_cyl;
498 503
499 // Prepare the Hard Disk Footer 504 // Prepare the Hard Disk Footer
qemu-img.c
  View file @6e9ea0c
@@ -306,6 +306,8 @@ static int img_create(int argc, char **argv) @@ -306,6 +306,8 @@ static int img_create(int argc, char **argv)
306 if (ret < 0) { 306 if (ret < 0) {
307 if (ret == -ENOTSUP) { 307 if (ret == -ENOTSUP) {
308 error("Formatting or formatting option not supported for file format '%s'", fmt); 308 error("Formatting or formatting option not supported for file format '%s'", fmt);
  309 + } else if (ret == -EFBIG) {
  310 + error("The image size is too large for file format '%s'", fmt);
309 } else { 311 } else {
310 error("Error while formatting"); 312 error("Error while formatting");
311 } 313 }
@@ -494,6 +496,8 @@ static int img_convert(int argc, char **argv) @@ -494,6 +496,8 @@ static int img_convert(int argc, char **argv)
494 if (ret < 0) { 496 if (ret < 0) {
495 if (ret == -ENOTSUP) { 497 if (ret == -ENOTSUP) {
496 error("Formatting not supported for file format '%s'", out_fmt); 498 error("Formatting not supported for file format '%s'", out_fmt);
  499 + } else if (ret == -EFBIG) {
  500 + error("The image size is too large for file format '%s'", out_fmt);
497 } else { 501 } else {
498 error("Error while formatting '%s'", out_filename); 502 error("Error while formatting '%s'", out_filename);
499 } 503 }