Commit b3fa7e77 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

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: default avatarKent Overstreet <kmo@daterainc.com>
parent ef71ec00

drivers/md/bcache/journal.c

+14 −5
Original line number Diff line number Diff line
@@ -44,11 +44,11 @@ static int journal_read_bucket(struct cache *ca, struct list_head *list, 


	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 @@ reread: left = ca->sb.bucket_size - offset; 
			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);

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