From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CF912BD11; Tue, 10 Mar 2026 00:49:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773103762; cv=none; b=LnvA1So+iCwLPFMU5ZAsADx1diBA1zdf4l5Y+hASKj9/hbiGEuA0RV1xmXre5pzHznjEKZ67I1/gZOiR5j3Ht3vhODy92dchWb7WjdWDNkV9EucOviKQPA0uT2YU9/M5UZcPPQKnQ/tW0THEcWGbXdS49qI/fZ5I/nBxlv/yBZ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773103762; c=relaxed/simple; bh=lKqhCSJKZhdrvwjb4xNjYx38RXJz/jSpPgPv4ORSk7g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NIqwLi4K4/xzaSYG9gV8pmpqZnQip6Ff0gxCkJDsSD1zWa2XnLdA/ecQ+LWJmPp/9Xpy1a3qM0WuQv/FHPqc7uPSsPGddtv/+oUHkfD9JZi7jfkk7llWrtYP7l6JRgxu6Z8sxZ8d7s/7fiGzHuFq5oQnar8tdszh4bZ89gnG80k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mmaAN+jM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mmaAN+jM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA26AC4CEF7; Tue, 10 Mar 2026 00:49:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773103761; bh=lKqhCSJKZhdrvwjb4xNjYx38RXJz/jSpPgPv4ORSk7g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mmaAN+jMq0rvEauF80/acXKQ/iAaAxF0160S2i+MvLYETEOJpd/kFtHUPhjqxZhPw IK7G/40KXOkNL1sNkU/eVej+wKENlysw9Diem3lJ/pAbRKMlW+awA09S0VTrfvCoZm b1EzEfGHXJ+IGDljWW/yPGNR/WTAkObHRqjstTkLCMHjYhys400nuDxwywlnOK+Xe0 7ldJVN9/5queUv0MvMJtRA8a32UeTkvfgQHNvGw+zKeY/SHL0Wu+vpNXxl+NCo0Yy1 CnMo6LAn1LQKslel3ql27bEggplYSSf7LJHUoKHw+WR2rvw4vssq6kzhRKT2OgmFX/ ZNUv0Eqbh/20g== Date: Mon, 9 Mar 2026 17:49:21 -0700 From: "Darrick J. Wong" To: Andrey Albershteyn Cc: linux-xfs@vger.kernel.org, fsverity@lists.linux.dev, linux-fsdevel@vger.kernel.org, ebiggers@kernel.org, hch@lst.de, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-btrfs@vger.kernel.org Subject: Re: [PATCH v4 06/25] fsverity: hoist pagecache_read from f2fs/ext4 to fsverity Message-ID: <20260310004921.GX6033@frogsfrogsfrogs> References: <20260309192355.176980-1-aalbersh@kernel.org> <20260309192355.176980-7-aalbersh@kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260309192355.176980-7-aalbersh@kernel.org> On Mon, Mar 09, 2026 at 08:23:21PM +0100, Andrey Albershteyn wrote: > This is the same function to read from pageache. XFS will also need > this, so move this to core fsverity. > > Signed-off-by: Andrey Albershteyn This looks like a neat code reduction. :) Reviewed-by: "Darrick J. Wong" --D > --- > fs/ext4/verity.c | 32 +++----------------------------- > fs/f2fs/verity.c | 30 +----------------------------- > fs/verity/pagecache.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/fsverity.h | 2 ++ > 4 files changed, 39 insertions(+), 58 deletions(-) > > diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c > index 347945ac23a4..ac5c133f5529 100644 > --- a/fs/ext4/verity.c > +++ b/fs/ext4/verity.c > @@ -34,32 +34,6 @@ static inline loff_t ext4_verity_metadata_pos(const struct inode *inode) > return round_up(inode->i_size, 65536); > } > > -/* > - * Read some verity metadata from the inode. __vfs_read() can't be used because > - * we need to read beyond i_size. > - */ > -static int pagecache_read(struct inode *inode, void *buf, size_t count, > - loff_t pos) > -{ > - while (count) { > - struct folio *folio; > - size_t n; > - > - folio = read_mapping_folio(inode->i_mapping, pos >> PAGE_SHIFT, > - NULL); > - if (IS_ERR(folio)) > - return PTR_ERR(folio); > - > - n = memcpy_from_file_folio(buf, folio, pos, count); > - folio_put(folio); > - > - buf += n; > - pos += n; > - count -= n; > - } > - return 0; > -} > - > /* > * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY. > * kernel_write() can't be used because the file descriptor is readonly. > @@ -311,8 +285,8 @@ static int ext4_get_verity_descriptor_location(struct inode *inode, > goto bad; > desc_size_pos -= sizeof(desc_size_disk); > > - err = pagecache_read(inode, &desc_size_disk, sizeof(desc_size_disk), > - desc_size_pos); > + err = fsverity_pagecache_read(inode, &desc_size_disk, > + sizeof(desc_size_disk), desc_size_pos); > if (err) > return err; > desc_size = le32_to_cpu(desc_size_disk); > @@ -352,7 +326,7 @@ static int ext4_get_verity_descriptor(struct inode *inode, void *buf, > if (buf_size) { > if (desc_size > buf_size) > return -ERANGE; > - err = pagecache_read(inode, buf, desc_size, desc_pos); > + err = fsverity_pagecache_read(inode, buf, desc_size, desc_pos); > if (err) > return err; > } > diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c > index b3b3e71604ac..5ea0a9b40443 100644 > --- a/fs/f2fs/verity.c > +++ b/fs/f2fs/verity.c > @@ -36,34 +36,6 @@ static inline loff_t f2fs_verity_metadata_pos(const struct inode *inode) > return round_up(inode->i_size, 65536); > } > > -/* > - * Read some verity metadata from the inode. __vfs_read() can't be used because > - * we need to read beyond i_size. > - */ > -static int pagecache_read(struct inode *inode, void *buf, size_t count, > - loff_t pos) > -{ > - while (count) { > - size_t n = min_t(size_t, count, > - PAGE_SIZE - offset_in_page(pos)); > - struct page *page; > - > - page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT, > - NULL); > - if (IS_ERR(page)) > - return PTR_ERR(page); > - > - memcpy_from_page(buf, page, offset_in_page(pos), n); > - > - put_page(page); > - > - buf += n; > - pos += n; > - count -= n; > - } > - return 0; > -} > - > /* > * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY. > * kernel_write() can't be used because the file descriptor is readonly. > @@ -248,7 +220,7 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf, > if (buf_size) { > if (size > buf_size) > return -ERANGE; > - res = pagecache_read(inode, buf, size, pos); > + res = fsverity_pagecache_read(inode, buf, size, pos); > if (res) > return res; > } > diff --git a/fs/verity/pagecache.c b/fs/verity/pagecache.c > index 1d94bf73f38c..ec65f60e657f 100644 > --- a/fs/verity/pagecache.c > +++ b/fs/verity/pagecache.c > @@ -78,3 +78,36 @@ void fsverity_folio_zero_hash(struct folio *folio, size_t poff, size_t plen, > vi->tree_params.digest_size); > } > EXPORT_SYMBOL_GPL(fsverity_folio_zero_hash); > + > +/** > + * fsverity_pagecache_read() - read page and copy data to buffer > + * @inode: copy from this inode's address space > + * @buf: buffer to copy to > + * @count: number of bytes to copy > + * @pos: position of the folio to copy from > + * > + * Read some verity metadata from the inode. __vfs_read() can't be used because > + * we need to read beyond i_size. > + */ > +int fsverity_pagecache_read(struct inode *inode, void *buf, size_t count, > + loff_t pos) > +{ > + while (count) { > + struct folio *folio; > + size_t n; > + > + folio = read_mapping_folio(inode->i_mapping, pos >> PAGE_SHIFT, > + NULL); > + if (IS_ERR(folio)) > + return PTR_ERR(folio); > + > + n = memcpy_from_file_folio(buf, folio, pos, count); > + folio_put(folio); > + > + buf += n; > + pos += n; > + count -= n; > + } > + return 0; > +} > +EXPORT_SYMBOL_GPL(fsverity_pagecache_read); > diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h > index 1ca8de129323..53dc161e18c0 100644 > --- a/include/linux/fsverity.h > +++ b/include/linux/fsverity.h > @@ -327,5 +327,7 @@ void generic_readahead_merkle_tree(struct inode *inode, pgoff_t index, > unsigned long nr_pages); > void fsverity_folio_zero_hash(struct folio *folio, size_t poff, size_t plen, > struct fsverity_info *vi); > +int fsverity_pagecache_read(struct inode *inode, void *buf, size_t count, > + loff_t pos); > > #endif /* _LINUX_FSVERITY_H */ > -- > 2.51.2 > >