Re: [PATCH v3] common/rc: add _require_blocks_in_file helper

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Feb 09, 2026 at 03:50:43AM +0800, Zorro Lang wrote:
> On Mon, Jan 12, 2026 at 11:20:36AM +0800, Joanne Chang wrote:
> > On Sat, Jan 10, 2026 at 9:38 AM Darrick J. Wong <djwong@kernel.org> wrote:
> > > On Thu, Jan 08, 2026 at 02:25:01AM +0000, Joanne Chang wrote:
> > > > generic/735 attempts to create a file with nearly 2^32 blocks. However,
> > > > some filesystems have a maximum file block limit below this threshold.
> > > > For instance, F2FS is limited to approximately 2^30 blocks due to the
> > > > capacity of the inode. So add _require_blocks_in_file helper to skip the
> > > > test in such cases.
> > > >
> > > > The helper uses a hardcoded constant instead of a programmatic method,
> > > > so that bugs which affect the maximum file size are not masked.
> > >
> > > Not to mention trying to create a file with 1,057,053,439 blocks
> > > allocated to it would probably take forever.
> > >
> > > Hang on, we're talking about iblocks (aka the number of blocks allocated
> > > to this inode), not the maximum file size in blocks, right?
> > >
> > > If so, then maybe this function and its comments should
> > > s/blocks/iblocks/?  Or am I confused? ;)
> > >
> > > --D
> > 
> > If I understand correctly, generic/735 creates a large logical file, but
> > the actual physical block allocation is much smaller. Also, the F2FS
> > limitation is about how many blocks the inode can address, no matter if
> > the blocks are actually allocated.
> > 
> > So I believe the requirement is about the maximum file size in blocks,
> > not the number of blocks actually allocated. Does it make sense to keep
> > the name, or do you think another term would be clearer? I appreciate
> > your thoughts on this.
> 
> Hi Darrick,
> 
> I think Joanne's explanation makes sense, if you don't have more review points
> on it, I'll merge this patch.

Agpgth, I didn't notice this reply!  My apologies! :(

Ok, since this is a limit on the maximum logical file block number,
_require_max_file_range_blocks, perhaps?

--D

> 
> Thanks,
> Zorro
> 
> > 
> > Best regards,
> > Joanne
> > 
>