[PATCH 3/4] xfs: fix double free in xlog_recover_commit_trans

Dave Chinner
2014-08-26T01:21:55Z

From: Dave Chinner <dchinner@redhat.com>

When an error occurs during buffer submission in
xlog_recover_commit_trans(), we free the trans structure twice. Fix
it by only freeing the structure in the caller regardless of the
success or failure of the function.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_log_recover.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 460cf98..23895d5 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -3524,8 +3524,6 @@ out:
if (!list_empty(&done_list))
list_splice_init(&done_list, &trans->r_itemq);

- xlog_recover_free_trans(trans);
-
error2 = xfs_buf_delwri_submit(&buffer_list);
return error ? error : error2;
}
@@ -3571,6 +3569,11 @@ xlog_recovery_process_ophdr(
if (flags & XLOG_WAS_CONT_TRANS)
flags &= ~XLOG_CONTINUE_TRANS;

+ /*
+ * Callees must not free the trans structure. We own it, so we'll decide
+ * if we need to free it or not based on the operation being done and
+ * it's result.
+ */
switch (flags) {
/* expected flag values */
case 0:
@@ -3582,7 +3585,8 @@ xlog_recovery_process_ophdr(
break;
case XLOG_COMMIT_TRANS:
error = xlog_recover_commit_trans(log, trans, pass);
- break;
+ xlog_recover_free_trans(trans);
+ return error;

/* unexpected flag values */
case XLOG_UNMOUNT_TRANS:
--
2.0.0