On Thu, 21 Feb 2013, Zheng Liu wrote: ..snip.. > > > > > /* > > > > > * All of the blocks before first_data_block are overhead > > > > > */ > > > > > - overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block)); > > > > > + overhead = EXT4_NUM_B2C(sbi, le32_to_cpu(es->s_first_data_block)); > > > > > > ...except this. I do not think this is right because we do not skip > > > the first cluster right ? We're still using it, but we can never use > > > the block before es->s_first_data_block. Please correct me if I am > > > wrong. > > Yes, I think you are right. > > > > > moreover we do not allow bigalloc file system with block size < 4k. > > No, we allow user to use bigalloc with block size < 4k, such as: > > mkfs.ext4 -b 1024 -C 4096 -O bigalloc ${dev} > > This command formats a bigalloc filesystem with blocksize = 1k and > clustersize = 4k, at least in e2fsprogs 1.42.7 it works well. > Ok, i was pretty sure that we do not allow that, it's good to know. Also, does it make any sense ? I do not think so, and I would really consider the fact that we allow that as a bug. We should not allow that otherwise it unnecessarily extending the test matrix. What people think about restricting bigalloc _only_ for 4k block size file systems ? Thanks! -Lukas -- 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