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authorMikulas Patocka <mpatocka@redhat.com>2024-02-20 19:11:51 +0100
committerSasha Levin <sashal@kernel.org>2024-03-26 18:20:26 -0400
commitb22b54f247f601a0896092c779d4c6bb80038475 (patch)
tree5963478b1a6c4bc1c4bb5ab5bc869a516929a223
parent6fb80b3e75b5ab85ca7eeb1e5cba33b5f1d2d0db (diff)
dm-verity, dm-crypt: align "struct bvec_iter" correctly
[ Upstream commit 787f1b2800464aa277236a66eb3c279535edd460 ] "struct bvec_iter" is defined with the __packed attribute, so it is aligned on a single byte. On X86 (and on other architectures that support unaligned addresses in hardware), "struct bvec_iter" is accessed using the 8-byte and 4-byte memory instructions, however these instructions are less efficient if they operate on unaligned addresses. (on RISC machines that don't have unaligned access in hardware, GCC generates byte-by-byte accesses that are very inefficient - see [1]) This commit reorders the entries in "struct dm_verity_io" and "struct convert_context", so that "struct bvec_iter" is aligned on 8 bytes. [1] https://lore.kernel.org/all/ZcLuWUNRZadJr0tQ@fedora/T/ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/md/dm-crypt.c4
-rw-r--r--drivers/md/dm-verity.h4
2 files changed, 4 insertions, 4 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3e215aa85b99..e8c534b5870a 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -52,11 +52,11 @@
struct convert_context {
struct completion restart;
struct bio *bio_in;
- struct bio *bio_out;
struct bvec_iter iter_in;
+ struct bio *bio_out;
struct bvec_iter iter_out;
- u64 cc_sector;
atomic_t cc_pending;
+ u64 cc_sector;
union {
struct skcipher_request *req;
struct aead_request *req_aead;
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index 4620a98c9956..db93a91169d5 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -80,12 +80,12 @@ struct dm_verity_io {
/* original value of bio->bi_end_io */
bio_end_io_t *orig_bi_end_io;
+ struct bvec_iter iter;
+
sector_t block;
unsigned int n_blocks;
bool in_tasklet;
- struct bvec_iter iter;
-
struct work_struct work;
char *recheck_buffer;