Linux-XFS Archive mirror
 help / color / mirror / Atom feed
From: "Darrick J. Wong" <djwong@kernel.org>
To: djwong@kernel.org, ebiggers@kernel.org, aalbersh@redhat.com
Cc: linux-fsdevel@vger.kernel.org, fsverity@lists.linux.dev,
	linux-xfs@vger.kernel.org
Subject: [PATCH 16/40] fsverity: pass the zero-hash value to the implementation
Date: Sun, 17 Mar 2024 09:27:34 -0700	[thread overview]
Message-ID: <171069246170.2684506.16175333193381403848.stgit@frogsfrogsfrogs> (raw)
In-Reply-To: <171069245829.2684506.10682056181611490828.stgit@frogsfrogsfrogs>

From: Darrick J. Wong <djwong@kernel.org>

Compute the hash of a data block full of zeros, and then supply this to
the merkle tree read and write methods.  A subsequent xfs patch will use
this to reduce the size of the merkle tree when dealing with sparse gold
master disk images and the like.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/verity/enable.c           |    2 ++
 fs/verity/fsverity_private.h |    2 ++
 fs/verity/open.c             |    7 +++++++
 fs/verity/verify.c           |    2 ++
 include/linux/fsverity.h     |    8 ++++++++
 5 files changed, 21 insertions(+)


diff --git a/fs/verity/enable.c b/fs/verity/enable.c
index 8dcfefc848ee..06b769dd1bdf 100644
--- a/fs/verity/enable.c
+++ b/fs/verity/enable.c
@@ -52,6 +52,8 @@ static int write_merkle_tree_block(struct inode *inode, const u8 *buf,
 {
 	struct fsverity_writemerkle req = {
 		.inode = inode,
+		.zero_digest = params->zero_digest,
+		.digest_size = params->digest_size,
 	};
 	u64 pos = (u64)index << params->log_blocksize;
 	int err;
diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h
index de8798f141d4..195a92f203bb 100644
--- a/fs/verity/fsverity_private.h
+++ b/fs/verity/fsverity_private.h
@@ -47,6 +47,8 @@ struct merkle_tree_params {
 	u64 tree_size;			/* Merkle tree size in bytes */
 	unsigned long tree_pages;	/* Merkle tree size in pages */
 
+	u8 zero_digest[FS_VERITY_MAX_DIGEST_SIZE]; /* hash of zeroed data block */
+
 	/*
 	 * Starting block index for each tree level, ordered from leaf level (0)
 	 * to root level ('num_levels - 1')
diff --git a/fs/verity/open.c b/fs/verity/open.c
index 7a86407732c4..433a70eeca55 100644
--- a/fs/verity/open.c
+++ b/fs/verity/open.c
@@ -144,6 +144,13 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params,
 		goto out_err;
 	}
 
+	err = fsverity_hash_buffer(params->hash_alg, page_address(ZERO_PAGE(0)),
+				   i_blocksize(inode), params->zero_digest);
+	if (err) {
+		fsverity_err(inode, "Error %d computing zero digest", err);
+		goto out_err;
+	}
+
 	params->tree_size = offset << log_blocksize;
 	params->tree_pages = PAGE_ALIGN(params->tree_size) >> PAGE_SHIFT;
 	return 0;
diff --git a/fs/verity/verify.c b/fs/verity/verify.c
index a61d1c99c485..494225f60608 100644
--- a/fs/verity/verify.c
+++ b/fs/verity/verify.c
@@ -409,6 +409,8 @@ int fsverity_read_merkle_tree_block(struct inode *inode,
 			.num_levels = params->num_levels,
 			.log_blocksize = params->log_blocksize,
 			.ra_bytes = ra_bytes,
+			.zero_digest = params->zero_digest,
+			.digest_size = params->digest_size,
 		};
 		block->verified = false;
 
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 0dded1fcf2b1..da23f1e30151 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -66,6 +66,8 @@ struct fsverity_blockbuf {
  *		if the page at @block->offset isn't already cached.
  *		Implementations may ignore this argument; it's only a
  *		performance optimization.
+ * @zero_digest: the hash for a data block of zeroes
+ * @digest_size: size of zero_digest
  */
 struct fsverity_readmerkle {
 	struct inode *inode;
@@ -73,6 +75,8 @@ struct fsverity_readmerkle {
 	int level;
 	int num_levels;
 	u8 log_blocksize;
+	const u8 *zero_digest;
+	unsigned int digest_size;
 };
 
 /**
@@ -81,12 +85,16 @@ struct fsverity_readmerkle {
  * @level: level of the block; level 0 are the leaves
  * @num_levels: number of levels in the tree total
  * @log_blocksize: log2 of the size of the block
+ * @zero_digest: the hash for a data block of zeroes
+ * @digest_size: size of zero_digest
  */
 struct fsverity_writemerkle {
 	struct inode *inode;
 	int level;
 	int num_levels;
 	u8 log_blocksize;
+	const u8 *zero_digest;
+	unsigned int digest_size;
 };
 
 /* Verity operations for filesystems */


  parent reply	other threads:[~2024-03-17 16:27 UTC|newest]

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-17 16:19 [PATCHBOMB v5.3] fs-verity support for XFS Darrick J. Wong
2024-03-17 16:22 ` [PATCHSET " Darrick J. Wong
2024-03-17 16:23   ` [PATCH 01/40] fsverity: remove hash page spin lock Darrick J. Wong
2024-03-17 16:23   ` [PATCH 02/40] xfs: add parent pointer support to attribute code Darrick J. Wong
2024-03-17 16:24   ` [PATCH 03/40] xfs: define parent pointer ondisk extended attribute format Darrick J. Wong
2024-03-17 16:24   ` [PATCH 04/40] xfs: add parent pointer validator functions Darrick J. Wong
2024-03-17 16:24   ` [PATCH 05/40] fs: add FS_XFLAG_VERITY for verity files Darrick J. Wong
2024-03-17 16:24   ` [PATCH 06/40] fsverity: pass tree_blocksize to end_enable_verity() Darrick J. Wong
2024-03-17 16:25   ` [PATCH 07/40] fsverity: support block-based Merkle tree caching Darrick J. Wong
2024-03-17 16:25   ` [PATCH 08/40] fsverity: add per-sb workqueue for post read processing Darrick J. Wong
2024-03-17 16:25   ` [PATCH 09/40] fsverity: add tracepoints Darrick J. Wong
2024-03-17 16:26   ` [PATCH 10/40] fsverity: fix "support block-based Merkle tree caching" Darrick J. Wong
2024-03-17 16:26   ` [PATCH 11/40] fsverity: send the level of the merkle tree block to ->read_merkle_tree_block Darrick J. Wong
2024-03-17 16:26   ` [PATCH 12/40] fsverity: pass the new tree size and block size to ->begin_enable_verity Darrick J. Wong
2024-03-17 16:26   ` [PATCH 13/40] fsverity: expose merkle tree geometry to callers Darrick J. Wong
2024-03-17 16:27   ` [PATCH 14/40] fsverity: rely on cached block callers to retain verified state Darrick J. Wong
2024-03-17 16:27   ` [PATCH 15/40] fsverity: box up the write_merkle_tree_block parameters too Darrick J. Wong
2024-03-17 16:27   ` Darrick J. Wong [this message]
2024-03-18 16:38     ` [PATCH 16/40] fsverity: pass the zero-hash value to the implementation Eric Biggers
2024-03-18 21:04       ` Darrick J. Wong
2024-03-17 16:27   ` [PATCH 17/40] fsverity: report validation errors back to the filesystem Darrick J. Wong
2024-03-17 16:28   ` [PATCH 18/40] iomap: integrate fs-verity verification into iomap's read path Darrick J. Wong
2024-03-17 16:28   ` [PATCH 19/40] xfs: add attribute type for fs-verity Darrick J. Wong
2024-03-17 16:28   ` [PATCH 20/40] xfs: add fs-verity ro-compat flag Darrick J. Wong
2024-03-17 16:28   ` [PATCH 21/40] xfs: add inode on-disk VERITY flag Darrick J. Wong
2024-03-17 16:29   ` [PATCH 22/40] xfs: initialize fs-verity on file open and cleanup on inode destruction Darrick J. Wong
2024-03-17 16:29   ` [PATCH 23/40] xfs: don't allow to enable DAX on fs-verity sealed inode Darrick J. Wong
2024-03-17 16:29   ` [PATCH 24/40] xfs: disable direct read path for fs-verity files Darrick J. Wong
2024-03-18 19:48     ` Andrey Albershteyn
2024-03-19 21:17       ` Darrick J. Wong
2024-03-17 16:29   ` [PATCH 25/40] xfs: widen flags argument to the xfs_iflags_* helpers Darrick J. Wong
2024-03-17 16:30   ` [PATCH 26/40] xfs: add fs-verity support Darrick J. Wong
2024-03-18  1:43     ` Christoph Hellwig
2024-03-18  4:34       ` Darrick J. Wong
2024-03-18  4:39         ` Christoph Hellwig
2024-03-18  4:56           ` Darrick J. Wong
2024-03-17 16:30   ` [PATCH 27/40] xfs: create a per-mount shrinker for verity inodes merkle tree blocks Darrick J. Wong
2024-03-17 16:30   ` [PATCH 28/40] xfs: create an icache tag for files with cached " Darrick J. Wong
2024-03-17 16:30   ` [PATCH 29/40] xfs: shrink verity blob cache Darrick J. Wong
2024-03-17 16:31   ` [PATCH 30/40] xfs: clean up stale fsverity metadata before starting Darrick J. Wong
2024-03-18 17:50     ` Andrey Albershteyn
2024-03-17 16:31   ` [PATCH 31/40] xfs: better reporting and error handling in xfs_drop_merkle_tree Darrick J. Wong
2024-03-18 17:51     ` Andrey Albershteyn
2024-03-17 16:31   ` [PATCH 32/40] xfs: make scrub aware of verity dinode flag Darrick J. Wong
2024-03-17 16:32   ` [PATCH 33/40] xfs: add fs-verity ioctls Darrick J. Wong
2024-03-17 16:32   ` [PATCH 34/40] xfs: advertise fs-verity being available on filesystem Darrick J. Wong
2024-03-17 16:32   ` [PATCH 35/40] xfs: teach online repair to evaluate fsverity xattrs Darrick J. Wong
2024-03-18 17:34     ` Andrey Albershteyn
2024-03-19 21:27       ` Darrick J. Wong
2024-03-17 16:32   ` [PATCH 36/40] xfs: don't store trailing zeroes of merkle tree blocks Darrick J. Wong
2024-03-18 17:52     ` Andrey Albershteyn
2024-03-17 16:33   ` [PATCH 37/40] xfs: create separate name hash function for xattrs Darrick J. Wong
2024-03-18 17:53     ` Andrey Albershteyn
2024-03-17 16:33   ` [PATCH 38/40] xfs: use merkle tree offset as attr hash Darrick J. Wong
2024-03-18 17:55     ` Andrey Albershteyn
2024-03-17 16:33   ` [PATCH 39/40] xfs: don't bother storing merkle tree blocks for zeroed data blocks Darrick J. Wong
2024-03-18 17:56     ` Andrey Albershteyn
2024-03-17 16:33   ` [PATCH 40/40] xfs: enable ro-compat fs-verity flag Darrick J. Wong
2024-03-18 16:35   ` [PATCHSET v5.3] fs-verity support for XFS Eric Biggers
2024-03-19 22:07     ` Darrick J. Wong
2024-03-19 23:21       ` Darrick J. Wong
2024-03-20 10:16         ` Andrey Albershteyn
2024-03-20 15:11           ` Darrick J. Wong
2024-03-17 16:23 ` Darrick J. Wong
2024-03-17 16:34   ` [PATCH 01/20] xfsprogs: add parent pointer support to attribute code Darrick J. Wong
2024-03-17 16:34   ` [PATCH 02/20] xfsprogs: define parent pointer xattr format Darrick J. Wong
2024-03-17 16:34   ` [PATCH 03/20] xfsprogs: Add xfs_verify_pptr Darrick J. Wong
2024-03-17 16:34   ` [PATCH 04/20] fs: add FS_XFLAG_VERITY for verity files Darrick J. Wong
2024-03-17 16:35   ` [PATCH 05/20] xfs: add attribute type for fs-verity Darrick J. Wong
2024-03-17 16:35   ` [PATCH 06/20] xfs: add fs-verity ro-compat flag Darrick J. Wong
2024-03-17 16:35   ` [PATCH 07/20] xfs: add inode on-disk VERITY flag Darrick J. Wong
2024-03-17 16:35   ` [PATCH 08/20] xfs: add fs-verity support Darrick J. Wong
2024-03-17 16:36   ` [PATCH 09/20] xfs: advertise fs-verity being available on filesystem Darrick J. Wong
2024-03-17 16:36   ` [PATCH 10/20] xfs: create separate name hash function for xattrs Darrick J. Wong
2024-03-17 16:36   ` [PATCH 11/20] xfs: use merkle tree offset as attr hash Darrick J. Wong
2024-03-17 16:36   ` [PATCH 12/20] xfs: enable ro-compat fs-verity flag Darrick J. Wong
2024-03-17 16:37   ` [PATCH 13/20] libfrog: add fsverity to xfs_report_geom output Darrick J. Wong
2024-03-17 16:37   ` [PATCH 14/20] xfs_db: introduce attr_modify command Darrick J. Wong
2024-03-17 16:37   ` [PATCH 15/20] xfs_db: make attr_set/remove/modify be able to handle fs-verity attrs Darrick J. Wong
2024-03-17 16:37   ` [PATCH 16/20] man: document attr_modify command Darrick J. Wong
2024-03-17 16:38   ` [PATCH 17/20] xfs_db: dump verity features and metadata Darrick J. Wong
2024-03-17 16:38   ` [PATCH 18/20] xfs_db: dump merkle tree data Darrick J. Wong
2024-03-17 16:38   ` [PATCH 19/20] xfs_repair: junk fsverity xattrs when unnecessary Darrick J. Wong
2024-03-17 16:39   ` [PATCH 20/20] mkfs.xfs: add verity parameter Darrick J. Wong
2024-03-17 16:23 ` [PATCHSET v5.3] fstests: fs-verity support for XFS Darrick J. Wong
2024-03-17 16:39   ` [PATCH 1/3] common/verity: enable fsverity " Darrick J. Wong
2024-03-17 16:39   ` [PATCH 2/3] xfs/{021,122}: adapt to fsverity xattrs Darrick J. Wong
2024-03-19 14:59     ` Andrey Albershteyn
2024-03-19 19:25       ` Darrick J. Wong
2024-03-17 16:39   ` [PATCH 3/3] common/populate: add verity files to populate xfs images Darrick J. Wong
2024-03-18  1:39 ` [PATCHBOMB v5.3] fs-verity support for XFS Christoph Hellwig
2024-03-18  4:30   ` Darrick J. Wong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=171069246170.2684506.16175333193381403848.stgit@frogsfrogsfrogs \
    --to=djwong@kernel.org \
    --cc=aalbersh@redhat.com \
    --cc=ebiggers@kernel.org \
    --cc=fsverity@lists.linux.dev \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).