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authorMikulas Patocka2024-02-20 19:11:51 +0100
committerMike Snitzer2024-02-20 13:34:32 -0500
commit787f1b2800464aa277236a66eb3c279535edd460 (patch)
tree03a370dd0d630c2285e52ef27bd9e85b18bf5f3a /drivers/md
parent42e15d12070b4ff9af2b980f1b65774c2dab0507 (diff)
dm-verity, dm-crypt: align "struct bvec_iter" correctly
"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>
Diffstat (limited to 'drivers/md')
-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 6044614bab76..f54cd6714af3 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -53,11 +53,11 @@
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;