From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandan Rajendra Subject: Re: [RFC PATCH 05/10] fsverity: Add call back to decide if verity check has to be performed Date: Thu, 21 Feb 2019 18:24:52 +0530 Message-ID: <3323472.mdDe8xBITV@localhost.localdomain> References: <20190218100433.20048-1-chandan@linux.ibm.com> <20190218100433.20048-6-chandan@linux.ibm.com> <20190219232649.GF12177@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1gwoSO-0007GM-Kn for linux-f2fs-devel@lists.sourceforge.net; Thu, 21 Feb 2019 13:32:08 +0000 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5] helo=mx0a-001b2d01.pphosted.com) by sfi-mx-4.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) id 1gwoSN-005B7n-4A for linux-f2fs-devel@lists.sourceforge.net; Thu, 21 Feb 2019 13:32:08 +0000 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1LDTw7V035844 for ; Thu, 21 Feb 2019 08:32:01 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qsv93hyd5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 21 Feb 2019 08:32:00 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Feb 2019 13:31:59 -0000 In-Reply-To: <20190219232649.GF12177@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Eric Biggers Cc: tytso@mit.edu, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, adilger.kernel@dilger.ca, jaegeuk@kernel.org, linux-ext4@vger.kernel.org On Wednesday, February 20, 2019 4:56:49 AM IST Eric Biggers wrote: > Hi Chandan, > > On Mon, Feb 18, 2019 at 03:34:28PM +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 > > --- > > fs/ext4/super.c | 9 +++++++++ > > fs/post_read_process.c | 5 +++-- > > include/linux/fsverity.h | 1 + > > 3 files changed, 13 insertions(+), 2 deletions(-) > > > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > > index 9314dddfbf34..2d7781ab6824 100644 > > --- a/fs/ext4/super.c > > +++ b/fs/ext4/super.c > > @@ -1428,10 +1428,19 @@ 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) > > +{ > > + if (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)) > > + return true; > > + else > > + return false; > > +} > > This can be simplified to: > > return index < (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; > You are right. > > + > > 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 */ > > Doesn't f2fs need this too? This patch only changes ext4. Yes, My plan was to get review comments about the current approach and then make corresponding changes in F2FS. > > > > > diff --git a/fs/post_read_process.c b/fs/post_read_process.c > > index 9720eeff0160..1f8663d70247 100644 > > --- a/fs/post_read_process.c > > +++ b/fs/post_read_process.c > > @@ -79,8 +79,9 @@ struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode, > > if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) > > post_read_steps |= 1 << STEP_DECRYPT; > > #ifdef CONFIG_FS_VERITY > > - if (inode->i_verity_info != NULL && > > - (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT))) > > + if (inode->i_verity_info != NULL > > + && inode->i_sb->s_vop->verity_required > > + && inode->i_sb->s_vop->verity_required(inode, index)) > > post_read_steps |= 1 << STEP_VERITY; > > If ->verity_required is NULL, shouldn't that be equivalent to > ->verity_required() returning true? > Yes, you are right about that. I will fix it in the next iteration of the patchset. > > #endif > > if (post_read_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); > > }; > > > > #ifdef CONFIG_FS_VERITY > > - Eric > > -- chandan