On 2024/10/28 11:59, Theodore Ts'o wrote: > On Mon, Oct 28, 2024 at 09:47:46AM +0800, Zhang Yi wrote: >> >> IIRC, at the moment, fixed metadata does not appear in the middle of >> the block group. > > The mke2fs from e2fsprogs will not create a file system like that > normally, no. *However* it is possible for fixed metadata to be in > the middle of the block group: > > * If resize2fs does an off-line file system growth without a resize inode > or the reserved blocks in the resize inode has been exhausted > * If e2fsck needs to reallocate some fixed metadata blocks as part of > repairing a (very badly) corrupted file system. > * If there are blocks reported to mke2fs when the file system is created > * If a non-standard mkfs.ext4 is used by some other operating system which > reimplemented mke2fs for some reason (for example, because they wanted > to avoid using GPL'ed code). > > So while these cases are quite uncommon, they *can* happen in the > wild, and we want GETFSMAP to be able to handle these file systems > correctly. > > Cheers, > Ha, I see, thank you for the correction. Cheers, Yi.
