fs/partition/msdos: fix unusable extended partition for > 512B sector
Smaller size than a minimum blocksize can't be used, after all it's
handled like 0 size.
For extended partition itself, this makes sure to use bigger size than one
logical sector size at least.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Daniel Taylor <Daniel.Taylor@wdc.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
index b783858..90be97f 100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -492,9 +492,16 @@
if (!size)
continue;
if (is_extended_partition(p)) {
- /* prevent someone doing mkfs or mkswap on an
- extended partition, but leave room for LILO */
- put_partition(state, slot, start, size == 1 ? 1 : 2);
+ /*
+ * prevent someone doing mkfs or mkswap on an
+ * extended partition, but leave room for LILO
+ * FIXME: this uses one logical sector for > 512b
+ * sector, although it may not be enough/proper.
+ */
+ sector_t n = 2;
+ n = min(size, max(sector_size, n));
+ put_partition(state, slot, start, n);
+
printk(" <");
parse_extended(state, bdev, start, size);
printk(" >");