bcache: Minor journal fix
The real fix is where we check the bytes we need against how much is
remaining - we also need to check for a journal entry bigger than our
buffer, we'll never write those and it would be bad if we tried to read
one.
Also improve the diagnostic messages.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 7eafdf0..29cccc5 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -44,11 +44,11 @@
closure_init_stack(&cl);
- pr_debug("reading %llu", (uint64_t) bucket);
+ pr_debug("reading %u", bucket_index);
while (offset < ca->sb.bucket_size) {
reread: left = ca->sb.bucket_size - offset;
- len = min_t(unsigned, left, PAGE_SECTORS * 8);
+ len = min_t(unsigned, left, PAGE_SECTORS << JSET_BITS);
bio_reset(bio);
bio->bi_iter.bi_sector = bucket + offset;
@@ -74,17 +74,26 @@
struct list_head *where;
size_t blocks, bytes = set_bytes(j);
- if (j->magic != jset_magic(&ca->sb))
+ if (j->magic != jset_magic(&ca->sb)) {
+ pr_debug("%u: bad magic", bucket_index);
return ret;
+ }
- if (bytes > left << 9)
+ if (bytes > left << 9 ||
+ bytes > PAGE_SIZE << JSET_BITS) {
+ pr_info("%u: too big, %zu bytes, offset %u",
+ bucket_index, bytes, offset);
return ret;
+ }
if (bytes > len << 9)
goto reread;
- if (j->csum != csum_set(j))
+ if (j->csum != csum_set(j)) {
+ pr_info("%u: bad csum, %zu bytes, offset %u",
+ bucket_index, bytes, offset);
return ret;
+ }
blocks = set_blocks(j, ca->set);
