diff mbox series

[v9,4/9] direct-io: add support for fscrypt using blk-crypto

Message ID 20210604210908.2105870-5-satyat@google.com (mailing list archive)
State New, archived
Headers show
Series add support for direct I/O with fscrypt using blk-crypto | expand

Commit Message

Satya Tangirala June 4, 2021, 9:09 p.m. UTC 
From: Eric Biggers <ebiggers@google.com>

Set bio crypt contexts on bios by calling into fscrypt when required,
and explicitly check for DUN continuity when adding pages to the bio.
(While DUN continuity is usually implied by logical block contiguity,
this is not the case when using certain fscrypt IV generation methods
like IV_INO_LBLK_32).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Co-developed-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/direct-io.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/direct-io.c b/fs/direct-io.c
index b2e86e739d7a..328ed7ac0094 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -24,6 +24,7 @@ 
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/fs.h>
+#include <linux/fscrypt.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/highmem.h>
@@ -392,6 +393,7 @@  dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	      sector_t first_sector, int nr_vecs)
 {
 	struct bio *bio;
+	struct inode *inode = dio->inode;
 
 	/*
 	 * bio_alloc() is guaranteed to return a bio when allowed to sleep and
@@ -399,6 +401,9 @@  dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	 */
 	bio = bio_alloc(GFP_KERNEL, nr_vecs);
 
+	fscrypt_set_bio_crypt_ctx(bio, inode,
+				  sdio->cur_page_fs_offset >> inode->i_blkbits,
+				  GFP_KERNEL);
 	bio_set_dev(bio, bdev);
 	bio->bi_iter.bi_sector = first_sector;
 	bio_set_op_attrs(bio, dio->op, dio->op_flags);
@@ -765,9 +770,17 @@  static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
 		 * current logical offset in the file does not equal what would
 		 * be the next logical offset in the bio, submit the bio we
 		 * have.
+		 *
+		 * When fscrypt inline encryption is used, data unit number
+		 * (DUN) contiguity is also required.  Normally that's implied
+		 * by logical contiguity.  However, certain IV generation
+		 * methods (e.g. IV_INO_LBLK_32) don't guarantee it.  So, we
+		 * must explicitly check fscrypt_mergeable_bio() too.
 		 */
 		if (sdio->final_block_in_bio != sdio->cur_page_block ||
-		    cur_offset != bio_next_offset)
+		    cur_offset != bio_next_offset ||
+		    !fscrypt_mergeable_bio(sdio->bio, dio->inode,
+					   cur_offset >> dio->inode->i_blkbits))
 			dio_bio_submit(dio, sdio);
 	}