ext2fs_zero_blocks: Avoid clearing more blocks than requested
This could cause certain mke2fs feature combinations to result in the
initial blocks of the inode table getting wiped out when the journal
is created.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index ca8e733..e55dcbd 100644
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -170,9 +170,11 @@
/* OK, do the write loop */
j=0;
while (j < num) {
- if (blk % STRIDE_LENGTH)
+ if (blk % STRIDE_LENGTH) {
count = STRIDE_LENGTH - (blk % STRIDE_LENGTH);
- else {
+ if (count > (num - j))
+ count = num - j;
+ } else {
count = num - j;
if (count > STRIDE_LENGTH)
count = STRIDE_LENGTH;