Here's a test script which demonstrates how we can up with an external extent tree block containing a single extent. It needs to run as root since it will be mounting a test file system image on /mnt. #!/bin/bash fs=/u1/test-fs.img num=128 max=$(expr $num \* 8) size=$(expr $num \* 32)k dd if=/dev/zero of=$fs bs=4k count=$(expr $max \* 4) mke2fs -t ext4 -b 4096 -qF $fs mount -t ext4 $fs /mnt cd /mnt fallocate -l $size test-file for i in $(seq 0 8 $max | sed -e '$d') ; do dd if=/dev/zero of=test-file conv=notrunc,nocreat bs=4k \ seek=$i count=1 > /dev/null 2>&1 done sync dd if=/dev/zero of=test-file conv=notrunc,nocreat \ bs=4k count=$max > /dev/null 2>&1 sync cd / umount /mnt debugfs $fs -R "stat test-file" -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
