Commit 3c845acd authored Nov 15, 2019 by Jan Kara Committed by Theodore Ts'o Nov 15, 2019

jbd2: make jbd2_handle_buffer_credits() handle reserved handles



The helper jbd2_handle_buffer_credits() doesn't correctly handle reserved
handles which can lead to crashes. Fix it getting of journal pointer to
work for reserved handles as well.

Fixes: a9a8344e ("ext4, jbd2: Provide accessor function for handle credits")
Reported-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191115102210.29445-1-jack@suse.cz


Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent 565333a1

include/linux/jbd2.h

+6 −2

Original line number	Diff line number	Diff line
		@@ -1627,10 +1627,14 @@ static inline tid_t jbd2_get_latest_transaction(journal_t *journal)
		return tid;
		}


		static inline int jbd2_handle_buffer_credits(handle_t *handle)
		{
		journal_t *journal = handle->h_transaction->t_journal;
		journal_t *journal;

		if (!handle->h_reserved)
		journal = handle->h_transaction->t_journal;
		else
		journal = handle->h_journal;

		return handle->h_total_credits -
		DIV_ROUND_UP(handle->h_revoke_credits_requested,

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