Ensure that byte swapping occurs on big endian architectures when
reading or writing the superblock.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
---
drivers/md/bcache/bcache.h | 12 ++++++++++++
drivers/md/bcache/super.c | 4 ++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 72b1ea4576d9..50ddc78596bf 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -784,6 +784,18 @@ static inline bool ptr_available(struct cache_set *c, const struct bkey *k,
bch_crc64(p, q - p); \
})
+/*
+ * Variant of csum_set() for data structures in which (i)->keys has type
+ * __le16.
+ */
+#define csum_set_le(i) ({ \
+ const void *p = (void *)(i) + sizeof(uint64_t); \
+ const void *q = bkey_idx((struct bkey *)(i)->d, \
+ le16_to_cpu((i)->keys)); \
+ \
+ bch_crc64(p, q - p); \
+})
+
/* Error handling macros */
#define btree_bug(b, ...) \
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 39bec137f636..31d700aecd56 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -110,7 +110,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
goto err;
err = "Bad checksum";
- if (s->csum != csum_set(s))
+ if (s->csum != csum_set_le(s))
goto err;
err = "Bad UUID";
@@ -236,7 +236,7 @@ static void __write_super(struct cache_sb *sb, struct bio *bio)
for (i = 0; i < sb->keys; i++)
out->d[i] = cpu_to_le64(sb->d[i]);
- out->csum = csum_set(out);
+ out->csum = csum_set_le(out);
pr_debug("ver %llu, flags %llu, seq %llu",
sb->version, sb->flags, sb->seq);
--
2.16.2
