[PATCH v1 1/2] erofs-utils: Relax the hardchecks on the blocksize

[Sandeep Dhavale]

On Wed, Aug 30, 2023 at 4:34 PM Gao Xiang <hsiangkao at linux.alibaba.com> wrote:
>
> Hi Sandeep,
>
> On 2023/8/31 07:16, Sandeep Dhavale wrote:
> > As erofs-utils supports different block sizes upto
> > EROFS_MAX_BLOCK_SIZE, relax the checks so same tools
> > can be used to create images for platforms where
> > page size can be greater than 4096.
> >
> > Signed-off-by: Sandeep Dhavale <dhavale at google.com>
> > ---
> >   lib/namei.c | 2 --
> >   mkfs/main.c | 9 +++++----
> >   2 files changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/lib/namei.c b/lib/namei.c
> > index 2bb1d4c..45dbcd3 100644
> > --- a/lib/namei.c
> > +++ b/lib/namei.c
> > @@ -144,8 +144,6 @@ int erofs_read_inode_from_disk(struct erofs_inode *vi)
> >               vi->u.chunkbits = sbi->blkszbits +
> >                       (vi->u.chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
> >       } else if (erofs_inode_is_data_compressed(vi->datalayout)) {
> > -             if (erofs_blksiz(vi->sbi) != EROFS_MAX_BLOCK_SIZE)
> > -                     return -EOPNOTSUPP;
> >               return z_erofs_fill_inode(vi);
> >       }
> >       return 0;
> > diff --git a/mkfs/main.c b/mkfs/main.c
> > index c03a7a8..37bf658 100644
> > --- a/mkfs/main.c
> > +++ b/mkfs/main.c
> > @@ -550,10 +550,11 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
> >               cfg.c_dbg_lvl = EROFS_ERR;
> >               cfg.c_showprogress = false;
> >       }
> > -     if (cfg.c_compr_alg[0] && erofs_blksiz(&sbi) != EROFS_MAX_BLOCK_SIZE) {
> > -             erofs_err("compression is unsupported for now with block size %u",
> > -                       erofs_blksiz(&sbi));
> > -             return -EINVAL;
> > +     if (cfg.c_compr_alg[0] && erofs_blksiz(&sbi) != getpagesize()) {
> > +             erofs_warn("subpage blocksize with compression is not yet "
> > +                     "supported. Compressed image will only work with "
> > +                     "arch pagesize = blocksize = %u bytes",
> > +                     erofs_blksiz(&sbi));
> >       }
>
> Thanks for the patches.
>
> I'm fine to relax  EROFS_MAX_BLOCK_SIZE check, yet could we
> add a check as erofs_blksiz <= EROFS_MAX_BLOCK_SIZE somewhere?
>
> Otherwise, we could suffer from stack overflow
> (if EROFS_MAX_BLOCK_SIZE is outdated or somewhat small...)
>
Hi Gao,
There is already a check in place for -b option to validate the block
size passed is within range [512..EROFS_MAX_BLOCK_SIZE] in function
mkfs_parse_options_cfg()

Please correct me if I misunderstood your comment.

Thanks,
Sandeep.
> Thanks,
> Gao Xiang