On Tue, Feb 11, 2020 at 04:02:16PM -0500, Eric Whitney wrote:
> The EXT4_EOFBLOCKS_FL inode flag is used to indicate whether a file
> contains unwritten blocks past i_size. It's set when ext4_fallocate
> is called with the KEEP_SIZE flag to extend a file with an unwritten
> extent. However, this flag hasn't been useful functionally since
> March, 2012, when a decision was made to remove it from ext4.
>
> All traces of EXT4_EOFBLOCKS_FL were removed from e2fsprogs version
> 1.42.2 by commit 010dc7b90d97 ("e2fsck: remove EXT4_EOFBLOCKS_FL flag
> handling") at that time. Now that enough time has passed to make
> e2fsprogs versions containing this modification common, this patch now
> removes the code associated with EXT4_EOFBLOCKS_FL from the kernel as
> well.
>
> This change has two implications. First, because pre-1.42.2 e2fsck
> versions only look for a problem if EXT4_EOFBLOCKS_FL is set, and
> because that bit will never be set by newer kernels containing this
> patch, old versions of e2fsck won't have a compatibility problem with
> files created by newer kernels.
>
> Second, newer kernels will not clear EXT4_EOFBLOCKS_FL inode flag bits
> belonging to a file written by an older kernel. If set, it will remain
> in that state until the file is deleted. Because e2fsck versions since
> 1.42.2 don't check the flag at all, no adverse effect is expected.
> However, pre-1.42.2 e2fsck versions that do check the flag may report
> that it is set when it ought not to be after a file has been truncated
> or had its unwritten blocks written. In this case, the old version of
> e2fsck will offer to clear the flag. No adverse effect would then
> occur whether the user chooses to clear the flag or not.
>
> Signed-off-by: Eric Whitney <enwlinux@xxxxxxxxx>
Applied, thanks.
- Ted
