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From: "Darrick J. Wong" <djwong@kernel.org>
To: djwong@kernel.org, ebiggers@kernel.org, aalbersh@redhat.com
Cc: Christoph Hellwig <hch@lst.de>,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	fsverity@lists.linux.dev
Subject: [PATCH 13/13] iomap: integrate fs-verity verification into iomap's read path
Date: Fri, 29 Mar 2024 17:36:04 -0700	[thread overview]
Message-ID: <171175868082.1987804.4008377696050953236.stgit@frogsfrogsfrogs> (raw)
In-Reply-To: <171175867829.1987804.15934006844321506283.stgit@frogsfrogsfrogs>

From: Andrey Albershteyn <aalbersh@redhat.com>

This patch adds fs-verity verification into iomap's read path. After
BIO's io operation is complete the data are verified against
fs-verity's Merkle tree. Verification work is done in a separate
workqueue.

The read path ioend iomap_read_ioend are stored side by side with
BIOs if FS_VERITY is enabled.

Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: fix doc warning]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/iomap/buffered-io.c |  128 +++++++++++++++++++++++++++++++++++++++++++++---
 include/linux/iomap.h  |    4 ++
 2 files changed, 125 insertions(+), 7 deletions(-)


diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 4e8e41c8b3c0e..9f9d929dfeebc 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -6,6 +6,7 @@
 #include <linux/module.h>
 #include <linux/compiler.h>
 #include <linux/fs.h>
+#include <linux/fsverity.h>
 #include <linux/iomap.h>
 #include <linux/pagemap.h>
 #include <linux/uio.h>
@@ -23,6 +24,8 @@
 
 #define IOEND_BATCH_SIZE	4096
 
+#define IOMAP_POOL_SIZE		(4 * (PAGE_SIZE / SECTOR_SIZE))
+
 typedef int (*iomap_punch_t)(struct inode *inode, loff_t offset, loff_t length);
 /*
  * Structure allocated for each folio to track per-block uptodate, dirty state
@@ -368,6 +371,110 @@ static inline bool iomap_block_needs_zeroing(const struct iomap_iter *iter,
 		pos >= i_size_read(iter->inode);
 }
 
+#ifdef CONFIG_FS_VERITY
+struct iomap_fsverity_bio {
+	struct work_struct	work;
+	struct bio		bio;
+};
+static struct bio_set *iomap_fsverity_bioset;
+
+static int iomap_fsverity_init_bioset(void)
+{
+	struct bio_set *bs, *old;
+	int error;
+
+	bs = kzalloc(sizeof(*bs), GFP_KERNEL);
+	if (!bs)
+		return -ENOMEM;
+
+	error = bioset_init(bs, IOMAP_POOL_SIZE,
+			    offsetof(struct iomap_fsverity_bio, bio),
+			    BIOSET_NEED_BVECS);
+	if (error) {
+		kfree(bs);
+		return error;
+	}
+
+	/*
+	 * This has to be atomic as readaheads can race to create the
+	 * bioset.  If someone set the pointer before us, we drop ours.
+	 */
+	old = cmpxchg(&iomap_fsverity_bioset, NULL, bs);
+	if (old) {
+		bioset_exit(bs);
+		kfree(bs);
+	}
+
+	return 0;
+}
+
+int iomap_init_fsverity(struct super_block *sb)
+{
+	int ret;
+
+	if (!iomap_fsverity_bioset) {
+		ret = iomap_fsverity_init_bioset();
+		if (ret)
+			return ret;
+	}
+
+	return fsverity_init_verify_wq(sb);
+}
+EXPORT_SYMBOL_GPL(iomap_init_fsverity);
+
+static void
+iomap_read_fsverify_end_io_work(struct work_struct *work)
+{
+	struct iomap_fsverity_bio *fbio =
+		container_of(work, struct iomap_fsverity_bio, work);
+
+	fsverity_verify_bio(&fbio->bio);
+	iomap_read_end_io(&fbio->bio);
+}
+
+static void
+iomap_read_fsverity_end_io(struct bio *bio)
+{
+	struct iomap_fsverity_bio *fbio =
+		container_of(bio, struct iomap_fsverity_bio, bio);
+
+	INIT_WORK(&fbio->work, iomap_read_fsverify_end_io_work);
+	queue_work(bio->bi_private, &fbio->work);
+}
+
+static struct bio *
+iomap_fsverity_read_bio_alloc(struct inode *inode, struct block_device *bdev,
+			    int nr_vecs, gfp_t gfp)
+{
+	struct bio *bio;
+
+	bio = bio_alloc_bioset(bdev, nr_vecs, REQ_OP_READ, gfp,
+			iomap_fsverity_bioset);
+	if (bio) {
+		bio->bi_private = inode->i_sb->s_verify_wq;
+		bio->bi_end_io = iomap_read_fsverity_end_io;
+	}
+	return bio;
+}
+#else
+# define iomap_fsverity_read_bio_alloc(...)	(NULL)
+# define iomap_fsverity_init_bioset(...)	(-EOPNOTSUPP)
+#endif /* CONFIG_FS_VERITY */
+
+static struct bio *iomap_read_bio_alloc(struct inode *inode,
+		struct block_device *bdev, int nr_vecs, gfp_t gfp)
+{
+	struct bio *bio;
+
+	if (fsverity_active(inode))
+		return iomap_fsverity_read_bio_alloc(inode, bdev, nr_vecs, gfp);
+
+	bio = bio_alloc(bdev, nr_vecs, REQ_OP_READ, gfp);
+	if (bio)
+		bio->bi_end_io = iomap_read_end_io;
+	return bio;
+}
+
 static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
 		struct iomap_readpage_ctx *ctx, loff_t offset)
 {
@@ -391,6 +498,12 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
 
 	if (iomap_block_needs_zeroing(iter, pos)) {
 		folio_zero_range(folio, poff, plen);
+		if (fsverity_active(iter->inode) &&
+		    !fsverity_verify_blocks(folio, plen, poff)) {
+			folio_set_error(folio);
+			goto done;
+		}
+
 		iomap_set_range_uptodate(folio, poff, plen);
 		goto done;
 	}
@@ -408,28 +521,29 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
 	    !bio_add_folio(ctx->bio, folio, plen, poff)) {
 		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
 		gfp_t orig_gfp = gfp;
-		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
 
 		if (ctx->bio)
 			submit_bio(ctx->bio);
 
 		if (ctx->rac) /* same as readahead_gfp_mask */
 			gfp |= __GFP_NORETRY | __GFP_NOWARN;
-		ctx->bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs),
-				     REQ_OP_READ, gfp);
+
+		ctx->bio = iomap_read_bio_alloc(iter->inode, iomap->bdev,
+				bio_max_segs(DIV_ROUND_UP(length, PAGE_SIZE)),
+				gfp);
+
 		/*
 		 * If the bio_alloc fails, try it again for a single page to
 		 * avoid having to deal with partial page reads.  This emulates
 		 * what do_mpage_read_folio does.
 		 */
 		if (!ctx->bio) {
-			ctx->bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ,
-					     orig_gfp);
+			ctx->bio = iomap_read_bio_alloc(iter->inode,
+					iomap->bdev, 1, orig_gfp);
 		}
 		if (ctx->rac)
 			ctx->bio->bi_opf |= REQ_RAHEAD;
 		ctx->bio->bi_iter.bi_sector = sector;
-		ctx->bio->bi_end_io = iomap_read_end_io;
 		bio_add_folio_nofail(ctx->bio, folio, plen, poff);
 	}
 
@@ -1987,7 +2101,7 @@ EXPORT_SYMBOL_GPL(iomap_writepages);
 
 static int __init iomap_init(void)
 {
-	return bioset_init(&iomap_ioend_bioset, 4 * (PAGE_SIZE / SECTOR_SIZE),
+	return bioset_init(&iomap_ioend_bioset, IOMAP_POOL_SIZE,
 			   offsetof(struct iomap_ioend, io_bio),
 			   BIOSET_NEED_BVECS);
 }
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6fc1c858013d1..d486ec62d4082 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -256,6 +256,10 @@ static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i)
 	return &i->iomap;
 }
 
+#ifdef CONFIG_FS_VERITY
+int iomap_init_fsverity(struct super_block *sb);
+#endif
+
 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops);
 int iomap_file_buffered_write_punch_delalloc(struct inode *inode,


  parent reply	other threads:[~2024-03-30  0:36 UTC|newest]

Thread overview: 111+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-30  0:30 [PATCHBOMB v5.5] fs-verity support for XFS Darrick J. Wong
2024-03-30  0:32 ` [PATCHSET v5.5 1/2] fs-verity: support merkle tree access by blocks Darrick J. Wong
2024-03-30  0:32   ` [PATCH 01/13] fs: add FS_XFLAG_VERITY for verity files Darrick J. Wong
2024-03-30  0:33   ` [PATCH 02/13] fsverity: pass tree_blocksize to end_enable_verity() Darrick J. Wong
2024-03-30  0:33   ` [PATCH 03/13] fsverity: support block-based Merkle tree caching Darrick J. Wong
2024-04-05  2:31     ` Eric Biggers
2024-04-24 21:25       ` Darrick J. Wong
2024-04-24 22:08         ` Eric Biggers
2024-04-25  0:27           ` Darrick J. Wong
2024-04-25  0:46             ` Eric Biggers
2024-04-25  0:53               ` Darrick J. Wong
2024-03-30  0:33   ` [PATCH 04/13] fsverity: add per-sb workqueue for post read processing Darrick J. Wong
2024-04-05  2:39     ` Eric Biggers
2024-04-24 21:33       ` Darrick J. Wong
2024-03-30  0:33   ` [PATCH 05/13] fsverity: add tracepoints Darrick J. Wong
2024-03-30  0:34   ` [PATCH 06/13] fsverity: send the level of the merkle tree block to ->read_merkle_tree_block Darrick J. Wong
2024-04-05  2:42     ` Eric Biggers
2024-04-25  0:30       ` Darrick J. Wong
2024-03-30  0:34   ` [PATCH 07/13] fsverity: pass the new tree size and block size to ->begin_enable_verity Darrick J. Wong
2024-04-05  2:46     ` Eric Biggers
2024-04-24 21:36       ` Darrick J. Wong
2024-03-30  0:34   ` [PATCH 08/13] fsverity: expose merkle tree geometry to callers Darrick J. Wong
2024-04-05  2:50     ` Eric Biggers
2024-04-25  0:45       ` Darrick J. Wong
2024-04-25  0:49         ` Eric Biggers
2024-04-25  1:01           ` Darrick J. Wong
2024-04-25  1:04             ` Eric Biggers
2024-03-30  0:35   ` [PATCH 09/13] fsverity: box up the write_merkle_tree_block parameters too Darrick J. Wong
2024-04-05  2:52     ` Eric Biggers
2024-04-25  0:46       ` Darrick J. Wong
2024-03-30  0:35   ` [PATCH 10/13] fsverity: pass the zero-hash value to the implementation Darrick J. Wong
2024-04-05  2:57     ` Eric Biggers
2024-04-24 19:02       ` Darrick J. Wong
2024-04-24 19:19         ` Eric Biggers
2024-04-24 20:23           ` Darrick J. Wong
2024-04-24 20:59             ` Eric Biggers
2024-04-24 21:43               ` Darrick J. Wong
2024-03-30  0:35   ` [PATCH 11/13] fsverity: report validation errors back to the filesystem Darrick J. Wong
2024-04-05  3:09     ` Eric Biggers
2024-04-24 18:18       ` Darrick J. Wong
2024-04-24 18:52         ` Eric Biggers
2024-04-24 19:03           ` Darrick J. Wong
2024-03-30  0:35   ` [PATCH 12/13] fsverity: remove system-wide workqueue Darrick J. Wong
2024-04-05  3:14     ` Eric Biggers
2024-04-24 18:05       ` Darrick J. Wong
2024-04-24 18:41         ` Eric Biggers
2024-04-29 10:15         ` Andrey Albershteyn
2024-04-29 16:35           ` Darrick J. Wong
2024-03-30  0:36   ` Darrick J. Wong [this message]
2024-03-30  0:32 ` [PATCHSET v5.5 2/2] xfs: fs-verity support Darrick J. Wong
2024-03-30  0:36   ` [PATCH 01/29] xfs: use unsigned ints for non-negative quantities in xfs_attr_remote.c Darrick J. Wong
2024-04-02  9:51     ` Andrey Albershteyn
2024-04-02 16:25       ` Darrick J. Wong
2024-03-30  0:36   ` [PATCH 02/29] xfs: turn XFS_ATTR3_RMT_BUF_SPACE into a function Darrick J. Wong
2024-04-02 10:09     ` Andrey Albershteyn
2024-03-30  0:36   ` [PATCH 03/29] xfs: create a helper to compute the blockcount of a max sized remote value Darrick J. Wong
2024-04-02 10:09     ` Andrey Albershteyn
2024-03-30  0:37   ` [PATCH 04/29] xfs: minor cleanups of xfs_attr3_rmt_blocks Darrick J. Wong
2024-04-02 10:11     ` Andrey Albershteyn
2024-03-30  0:37   ` [PATCH 05/29] xfs: add attribute type for fs-verity Darrick J. Wong
2024-03-30  0:37   ` [PATCH 06/29] xfs: do not use xfs_attr3_rmt_hdr for remote verity value blocks Darrick J. Wong
2024-03-30  0:37   ` [PATCH 07/29] xfs: add fs-verity ro-compat flag Darrick J. Wong
2024-03-30  0:38   ` [PATCH 08/29] xfs: add inode on-disk VERITY flag Darrick J. Wong
2024-03-30  0:38   ` [PATCH 09/29] xfs: initialize fs-verity on file open and cleanup on inode destruction Darrick J. Wong
2024-03-30  0:38   ` [PATCH 10/29] xfs: don't allow to enable DAX on fs-verity sealed inode Darrick J. Wong
2024-03-30  0:38   ` [PATCH 11/29] xfs: disable direct read path for fs-verity files Darrick J. Wong
2024-03-30  0:39   ` [PATCH 12/29] xfs: widen flags argument to the xfs_iflags_* helpers Darrick J. Wong
2024-04-02 12:37     ` Andrey Albershteyn
2024-04-02 16:27       ` Darrick J. Wong
2024-03-30  0:39   ` [PATCH 13/29] xfs: add fs-verity support Darrick J. Wong
2024-04-02  8:42     ` Andrey Albershteyn
2024-04-02 16:34       ` Darrick J. Wong
2024-04-25  1:14         ` Darrick J. Wong
2024-03-30  0:39   ` [PATCH 14/29] xfs: create a per-mount shrinker for verity inodes merkle tree blocks Darrick J. Wong
2024-04-05  3:16     ` Eric Biggers
2024-04-24 17:39       ` Darrick J. Wong
2024-03-30  0:39   ` [PATCH 15/29] xfs: create an icache tag for files with cached " Darrick J. Wong
2024-03-30  0:40   ` [PATCH 16/29] xfs: shrink verity blob cache Darrick J. Wong
2024-03-30  0:40   ` [PATCH 17/29] xfs: only allow the verity iflag for regular files Darrick J. Wong
2024-04-02 12:52     ` Andrey Albershteyn
2024-03-30  0:40   ` [PATCH 18/29] xfs: don't store trailing zeroes of merkle tree blocks Darrick J. Wong
2024-03-30  0:41   ` [PATCH 19/29] xfs: use merkle tree offset as attr hash Darrick J. Wong
2024-03-30  0:41   ` [PATCH 20/29] xfs: don't bother storing merkle tree blocks for zeroed data blocks Darrick J. Wong
2024-03-30  0:41   ` [PATCH 21/29] xfs: add fs-verity ioctls Darrick J. Wong
2024-03-30  0:41   ` [PATCH 22/29] xfs: advertise fs-verity being available on filesystem Darrick J. Wong
2024-04-02 13:44     ` Andrey Albershteyn
2024-03-30  0:42   ` [PATCH 23/29] xfs: make scrub aware of verity dinode flag Darrick J. Wong
2024-03-30  0:42   ` [PATCH 24/29] xfs: teach online repair to evaluate fsverity xattrs Darrick J. Wong
2024-04-02 15:42     ` Andrey Albershteyn
2024-04-02 16:42       ` Darrick J. Wong
2024-03-30  0:42   ` [PATCH 25/29] xfs: report verity failures through the health system Darrick J. Wong
2024-04-02 16:16     ` Andrey Albershteyn
2024-03-30  0:42   ` [PATCH 26/29] xfs: clear the verity iflag when not appropriate Darrick J. Wong
2024-04-02 16:26     ` Andrey Albershteyn
2024-03-30  0:43   ` [PATCH 27/29] xfs: make it possible to disable fsverity Darrick J. Wong
2024-04-02 17:15     ` Andrey Albershteyn
2024-04-02 23:25     ` Eric Biggers
2024-04-03  1:26       ` Darrick J. Wong
2024-03-30  0:43   ` [PATCH 28/29] xfs: allow verity files to be opened even if the fsverity metadata is damaged Darrick J. Wong
2024-04-02 18:04     ` Andrey Albershteyn
2024-04-02 20:00     ` Colin Walters
2024-04-02 22:52       ` Darrick J. Wong
2024-04-02 23:45         ` Eric Biggers
2024-04-03  1:34           ` Darrick J. Wong
2024-04-03  0:10         ` Colin Walters
2024-04-03  1:39           ` Darrick J. Wong
2024-04-03  1:59             ` Dave Chinner
2024-04-03  3:19               ` Darrick J. Wong
2024-04-03 22:22                 ` Dave Chinner
2024-04-03  8:35           ` Alexander Larsson
2024-03-30  0:43   ` [PATCH 29/29] xfs: enable ro-compat fs-verity flag Darrick J. Wong

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