From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 30 Apr 2019 22:10:38 +0100 From: Jeremy Sowden Subject: Re: [PATCH V2 03/13] fsverity: Add call back to decide if verity check has to be performed Message-ID: <20190430211037.GA30337@azazel.net> References: <20190428043121.30925-1-chandan@linux.ibm.com> <20190428043121.30925-4-chandan@linux.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="C7zPtVaVf+AK4Oqc" Content-Disposition: inline In-Reply-To: <20190428043121.30925-4-chandan@linux.ibm.com> To: Chandan Rajendra Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, ebiggers@kernel.org, jaegeuk@kernel.org, yuchao0@huawei.com, hch@infradead.org List-ID: --C7zPtVaVf+AK4Oqc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2019-04-28, at 10:01:11 +0530, Chandan Rajendra wrote: > Ext4 and F2FS store verity metadata in data extents (beyond > inode->i_size) associated with a file. But other filesystems might > choose alternative means to store verity metadata. Hence this commit > adds a callback function pointer to 'struct fsverity_operations' to > help in deciding if verity operation needs to performed against a > page-cache page holding file data. >=20 > Signed-off-by: Chandan Rajendra > --- > fs/ext4/super.c | 6 ++++++ > fs/f2fs/super.c | 6 ++++++ > fs/read_callbacks.c | 4 +++- > include/linux/fsverity.h | 1 + > 4 files changed, 16 insertions(+), 1 deletion(-) >=20 > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index aba724f82cc3..63d73b360f1d 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -1428,10 +1428,16 @@ static struct page *ext4_read_verity_metadata_pag= e(struct inode *inode, > return read_mapping_page(inode->i_mapping, index, NULL); > } > =20 > +static bool ext4_verity_required(struct inode *inode, pgoff_t index) > +{ > + return index < (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > +} > + > static const struct fsverity_operations ext4_verityops =3D { > .set_verity =3D ext4_set_verity, > .get_metadata_end =3D ext4_get_verity_metadata_end, > .read_metadata_page =3D ext4_read_verity_metadata_page, > + .verity_required =3D ext4_verity_required, > }; > #endif /* CONFIG_FS_VERITY */ > =20 > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index 2f75f06c784a..cd1299e1f92d 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -2257,10 +2257,16 @@ static struct page *f2fs_read_verity_metadata_pag= e(struct inode *inode, > return read_mapping_page(inode->i_mapping, index, NULL); > } > =20 > +static bool f2fs_verity_required(struct inode *inode, pgoff_t index) > +{ > + return index < (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > +} > + > static const struct fsverity_operations f2fs_verityops =3D { > .set_verity =3D f2fs_set_verity, > .get_metadata_end =3D f2fs_get_verity_metadata_end, > .read_metadata_page =3D f2fs_read_verity_metadata_page, > + .verity_required =3D f2fs_verity_required, > }; > #endif /* CONFIG_FS_VERITY */ > =20 > diff --git a/fs/read_callbacks.c b/fs/read_callbacks.c > index b6d5b95e67d7..6dea54b0baa9 100644 > --- a/fs/read_callbacks.c > +++ b/fs/read_callbacks.c > @@ -86,7 +86,9 @@ struct read_callbacks_ctx *get_read_callbacks_ctx(struc= t inode *inode, > read_callbacks_steps |=3D 1 << STEP_DECRYPT; > #ifdef CONFIG_FS_VERITY > if (inode->i_verity_info !=3D NULL && > - (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT))) > + ((inode->i_sb->s_vop->verity_required > + && inode->i_sb->s_vop->verity_required(inode, index)) > + || (inode->i_sb->s_vop->verity_required =3D=3D NULL))) I think this is a bit easier to follow: (inode->i_sb->s_vop->verity_required =3D=3D NULL ||=20 inode->i_sb->s_vop->verity_required(inode, index))) > read_callbacks_steps |=3D 1 << STEP_VERITY; > #endif > if (read_callbacks_steps) { > diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h > index 7c33b42abf1b..b83712d6c79a 100644 > --- a/include/linux/fsverity.h > +++ b/include/linux/fsverity.h > @@ -18,6 +18,7 @@ struct fsverity_operations { > int (*set_verity)(struct inode *inode, loff_t data_i_size); > int (*get_metadata_end)(struct inode *inode, loff_t *metadata_end_ret); > struct page *(*read_metadata_page)(struct inode *inode, pgoff_t index); > + bool (*verity_required)(struct inode *inode, pgoff_t index); > }; > =20 > #ifdef CONFIG_FS_VERITY > --=20 > 2.19.1 > > J. --C7zPtVaVf+AK4Oqc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEZ8d+2N/NBLDbUxIF0Z7UzfnX9sMFAlzIucUACgkQ0Z7UzfnX 9sOkXRAAs0l+X0JkJyKwhOumKmHaSj5HT2VmMeG/UIc6foqj7OA4MD54MqXai/i3 r5/wwc4chDGkoFajjz44ENIrRuAbhYNL/obh0yqcE7GyxxuSREjqENvygKW7GlNZ 185SnNSWPoQeL77oniXnImvZPQ824TMU0LbAAON0RpGWaFc6hm0fFih5aEqBBM+i O1kHDOV0rOoFT2edo4mSTZRNEAhbltznfgAKuIFRU6kay/tF6b6ie0Okev2XhzVu e74YCPm31oGXTLecBjvnXI/zDxXIeyvxhNtEh33uK3+IDPrHTnbZOKJeMYha0Rf5 S+r+DQOB2wvLwjhFY2WAo9SKt7NMGjwrvXMvHj55SuyvCfva77uoshEwfEnJy6Ts e+U39A5gG5/VSHJczktjx7wYGJMdCPPnE8abCAG3BnExPpJDQ2EPYfVtU2JAnioR v05ULHyZoTB/qwVaay/RxptrHdkhAP2L3l+kYs6ZY0OsNqtBKIVy6EfbFkZuetyh qbLsZurrkpmKaYsJQpKR2Yx8ih0Q37DRO9ejEh4BOiQimdGBRCmCYv5XeWDpHRlE xl/T9mQjdKV4YXvZtddzYpG5lYtQHfBGqGw5pY2qjcta94hvsFTVNfB5cFMgKUAT XoKPnH1IzjerW5Tz6qgPzpY44qIwOXaj6vFvIGdmUBrPH+dCIaE= =U+NG -----END PGP SIGNATURE----- --C7zPtVaVf+AK4Oqc--