The patch titled
jbd: fix BUG in journal_commit_transaction()
has been added to the -mm tree. Its filename is
jbd-fix-bug-in-journal_commit_transaction.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Jan Kara <jack@xxxxxxx>
Fix possible assertion failure in journal_commit_transaction() on
jh->b_next_transaction == NULL (when we are processing BJ_Forget list and
buffer is not jbddirty).
!jbddirty buffers can be placed on BJ_Forget list for example by
journal_forget() or by __dispose_buffer() - generally such buffer means
that it has been freed by this transaction.
Freed buffers should not be reallocated until the transaction has committed
(that's why we have the assertion there) but they *can* be reallocated when
the transaction has already been committed to disk and we are just
processing the BJ_Forget list (as soon as we remove b_committed_data from
the bitmap bh, ext3 will be able to reallocate buffers freed by the
committing transaction). So we have to also count with the case that the
buffer has been reallocated and b_next_transaction has been already set.
And one more subtle point: it can happen that we manage to reallocate the
buffer and also mark it jbddirty. Then we also add the freed buffer to the
checkpoint list of the committing trasaction. But that should do no harm.
Signed-off-by: Jan Kara <jack@xxxxxxx>
Acked-by: "Stephen C. Tweedie" <sct@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/jbd/commit.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)
diff -puN fs/jbd/commit.c~jbd-fix-bug-in-journal_commit_transaction fs/jbd/commit.c
--- devel/fs/jbd/commit.c~jbd-fix-bug-in-journal_commit_transaction 2006-04-20 15:32:46.000000000 -0700
+++ devel-akpm/fs/jbd/commit.c 2006-04-20 15:32:46.000000000 -0700
@@ -790,11 +790,22 @@ restart_loop:
jbd_unlock_bh_state(bh);
} else {
J_ASSERT_BH(bh, !buffer_dirty(bh));
- J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
- __journal_unfile_buffer(jh);
- jbd_unlock_bh_state(bh);
- journal_remove_journal_head(bh); /* needs a brelse */
- release_buffer_page(bh);
+ /* The buffer on BJ_Forget list and not jbddirty means
+ * it has been freed by this transaction and hence it
+ * could not have been reallocated until this
+ * transaction has committed. *BUT* it could be
+ * reallocated once we have written all the data to
+ * disk and before we process the buffer on BJ_Forget
+ * list. */
+ JBUFFER_TRACE(jh, "refile or unfile freed buffer");
+ __journal_refile_buffer(jh);
+ if (!jh->b_transaction) {
+ jbd_unlock_bh_state(bh);
+ /* needs a brelse */
+ journal_remove_journal_head(bh);
+ release_buffer_page(bh);
+ } else
+ jbd_unlock_bh_state(bh);
}
cond_resched_lock(&journal->j_list_lock);
}
_
Patches currently in -mm which might be from jack@xxxxxxx are
jbd-fix-bug-in-journal_commit_transaction.patch
use-list_add_tail-instead-of-list_add.patch
-
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