[Ocfs2-tools-devel] [PATCH 1/1] Fix a wrong usage of "startblk" during offline resize and backup super.

[Tao Ma]

During offline resize, opts.num_blocks indicates the block count for
the ocfs2 volume, not the increased block count. But update_backup_super
use the wrong meaning by mistake. So when we increase the block into a
a number which isn't aligned with cluster size, startblk will overflow
since fs->fs_blocks will be lower than num_blocks and no backup super
blocks will be allocated since ocfs2_set_backup_super will never be
called.

So record the old_blocks when we do offline resize and that is the
really start offset for the new blocks.

Signed-off-by: Tao Ma <tao.ma at oracle.com>
---
 tunefs.ocfs2/tunefs.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tunefs.ocfs2/tunefs.c b/tunefs.ocfs2/tunefs.c
index 85070f7..6b2db21 100644
--- a/tunefs.ocfs2/tunefs.c
+++ b/tunefs.ocfs2/tunefs.c
@@ -1195,12 +1195,12 @@ static errcode_t refresh_backup_super(ocfs2_filesys *fs)
 	return ret;
 }
 
-static errcode_t update_backup_super(ocfs2_filesys *fs, uint64_t newblocks)
+static errcode_t update_backup_super(ocfs2_filesys *fs, uint64_t startblk,
+				     uint64_t newblocks)
 {
 	errcode_t ret;
 	int num, i;
 	uint64_t *new_backup_super, blocks[OCFS2_MAX_BACKUP_SUPERBLOCKS];
-	uint64_t startblk = fs->fs_blocks - newblocks;
 
 	num = ocfs2_get_backup_super_offset(fs, blocks, ARRAY_SIZE(blocks));
 	if (!num)
@@ -1259,6 +1259,7 @@ int main(int argc, char **argv)
 	uint16_t max_slots;
 	uint64_t def_jrnl_size = 0;
 	uint64_t num_clusters;
+	uint64_t old_blocks = 0;
 	int dirty = 0;
 	char old_uuid[OCFS2_VOL_UUID_LEN * 2 + 1];
 	char new_uuid[OCFS2_VOL_UUID_LEN * 2 + 1];
@@ -1540,6 +1541,7 @@ int main(int argc, char **argv)
 
 	/* update volume size */
 	if (opts.num_blocks) {
+		old_blocks = fs->fs_blocks;
 		ret = update_volume_size(fs, &upd_blocks);
 		if (ret) {
 			com_err(opts.progname, ret,
@@ -1559,7 +1561,7 @@ int main(int argc, char **argv)
 	    OCFS2_HAS_COMPAT_FEATURE(OCFS2_RAW_SB(fs->fs_super),
 				     OCFS2_FEATURE_COMPAT_BACKUP_SB))) {
 		block_signals(SIG_BLOCK);
-		ret = update_backup_super(fs, opts.num_blocks);
+		ret = update_backup_super(fs, old_blocks, opts.num_blocks);
 		block_signals(SIG_UNBLOCK);
 		if (ret) {
 			com_err(opts.progname, ret,
-- 
1.5.3.2.g4f337