On Jan 31, 2008 11:14 -0500, Josef Bacik wrote: [snip excellent analysis] > So you get into this situation where > t_nr_buffers (the actual number of buffers that are on the transaction) is > greater than the number of buffers accounted for via t_outstanding_credits. > This presents a problem since as we loop through writting buffers to the > journal, we decrement t_outstanding_credits, and if t_nr_buffers is more than > t_outstanding_credits then we end up with a negative number for > t_outstanding_credits > > Signed-off-by: Josef Bacik <jbacik@xxxxxxxxxx> Do you know what kernel this problem was introduced in, or is this a long standing problem? Presumably the same is needed for jbd2? Once we have some decent amount of testing going on with ext4, I think it makes sense to merge the jbd2 changes back into jbd and return to a single code base, since there is nothing in the jbd2 code that ext3 can't also work with (i.e. all of the changes are properly isolated with compatibility flags and such). > @@ -1056,7 +1056,7 @@ static inline int jbd_space_needed(journal_t *journal) > int nblocks = journal->j_max_transaction_buffers; > if (journal->j_committing_transaction) > nblocks += journal->j_committing_transaction-> > - t_outstanding_credits; > + t_nr_buffers; (trivial) this can be moved back onto the previous line. > @@ -1168,7 +1168,7 @@ static inline int jbd_space_needed(journal_t *journal) > int nblocks = journal->j_max_transaction_buffers; > if (journal->j_committing_transaction) > nblocks += journal->j_committing_transaction-> > - t_outstanding_credits; > + t_nr_buffers; Same... Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
