Re: [f2fs-dev] [PATCH v2 2/2] f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl

[Daeho Jeong]

> The use of ?: here is a bit strange.  How about:
>
>         return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
>

Ack

> Likewise, EINVAL tends to be over-used, which makes it ambiguous.  Maybe use
> ENOPKG for the case where algorithm < COMPRESS_MAX but the algorithm wasn't
> compiled into the kernel?  That would be similar to how opening an encrypted
> file fails with ENOPKG when the encryption algorithm isn't available.

Ack

> How about EBUSY for f2fs_is_mmap_file(inode) || get_dirty_pages(inode),
> and EFBIG for inode->i_size != 0?

Ack

Thanks~!

2020년 10월 22일 (목) 오후 1:26, Eric Biggers <ebiggers@xxxxxxxxxx>님이 작성:
>
> On Thu, Oct 22, 2020 at 12:58:48PM +0900, Daeho Jeong wrote:
> > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> > index 7895186cc765..3b58a41223f8 100644
> > --- a/fs/f2fs/compress.c
> > +++ b/fs/f2fs/compress.c
> > @@ -514,6 +514,11 @@ bool f2fs_is_compress_backend_ready(struct inode *inode)
> >       return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
> >  }
> >
> > +bool f2fs_is_compress_algorithm_ready(unsigned char algorithm)
> > +{
> > +     return algorithm >= COMPRESS_MAX ? false : f2fs_cops[algorithm];
> > +}
>
> The use of ?: here is a bit strange.  How about:
>
>         return algorithm < COMPRESS_MAX && f2fs_cops[algorithm] != NULL;
>
> > +     if (option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
> > +                     option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
> > +                     !f2fs_is_compress_algorithm_ready(option.algorithm))
> > +             return -EINVAL;
>
> Likewise, EINVAL tends to be over-used, which makes it ambiguous.  Maybe use
> ENOPKG for the case where algorithm < COMPRESS_MAX but the algorithm wasn't
> compiled into the kernel?  That would be similar to how opening an encrypted
> file fails with ENOPKG when the encryption algorithm isn't available.
>
> > +     if (f2fs_is_mmap_file(inode) ||
> > +                     get_dirty_pages(inode) || inode->i_size) {
> > +             ret = -EINVAL;
> > +             goto out;
> > +     }
>
> How about EBUSY for f2fs_is_mmap_file(inode) || get_dirty_pages(inode),
> and EFBIG for inode->i_size != 0?
>
> - Eric