tree 1a012bbdb5cc787896df233ed667e8897cbe99a0
parent d7574ad08bac1ef89cb679d2c76c91ff9281c2e2
author Yongqiang Yang <xiaoqiangnk@gmail.com> 1346822750 -0400
committer Theodore Ts'o <tytso@mit.edu> 1346822750 -0400

ext4: don't copy non-existent gdt blocks when resizing

The resize code was copying blocks at the beginning of each block
group in order to copy the superblock and block group descriptor table
(gdt) blocks.  This was, unfortunately, being done even for block
groups that did not have super blocks or gdt blocks.  This is a
complete waste of perfectly good I/O bandwidth, to skip writing those
blocks for sparse bg's.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org