On Wednesday, May 1, 2019 2:40:38 AM IST Jeremy Sowden wrote:
> 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.
> >
> > Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxx>
> > ---
> > 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(-)
> >
> > 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_page(struct inode *inode,
> > return read_mapping_page(inode->i_mapping, index, NULL);
> > }
> >
> > +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 = {
> > .set_verity = ext4_set_verity,
> > .get_metadata_end = ext4_get_verity_metadata_end,
> > .read_metadata_page = ext4_read_verity_metadata_page,
> > + .verity_required = ext4_verity_required,
> > };
> > #endif /* CONFIG_FS_VERITY */
> >
> > 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_page(struct inode *inode,
> > return read_mapping_page(inode->i_mapping, index, NULL);
> > }
> >
> > +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 = {
> > .set_verity = f2fs_set_verity,
> > .get_metadata_end = f2fs_get_verity_metadata_end,
> > .read_metadata_page = f2fs_read_verity_metadata_page,
> > + .verity_required = f2fs_verity_required,
> > };
> > #endif /* CONFIG_FS_VERITY */
> >
> > 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(struct inode *inode,
> > read_callbacks_steps |= 1 << STEP_DECRYPT;
> > #ifdef CONFIG_FS_VERITY
> > if (inode->i_verity_info != 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 == NULL)))
>
> I think this is a bit easier to follow:
>
> (inode->i_sb->s_vop->verity_required == NULL ||
> inode->i_sb->s_vop->verity_required(inode, index)))
Yes, you are right. I will implement the changes suggested by you.
--
chandan
