Fix segfault with verify_async
At some point the filename was added to the report on verify failures,
however this broke verify_async, as the file pointer on the io_u is
set to NULL before the verify thread sees the io_u. The result is a
segfault when there is a verify mismatch.
This patch changes the semantics of a deferred free (IO_U_F_FREE_DEF)
to have already called put_file, but not set the file pointer to NULL.
This is safe to do as the file list is only freed after all the
verify threads have been terminated.
FYI - this is the minimal config to cause the error this patch fixes,
and is what I used to test the fix. (Not using thread still causes a
segfault, but it is reported more subtly since just a sub-process hits
it.)
[segv]
ioengine=null
size=4k
verify=meta
rw=read
thread
verify_async=1
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/io_u.c b/io_u.c
index d1f66a9..fc3ee49 100644
--- a/io_u.c
+++ b/io_u.c
@@ -597,13 +597,12 @@
{
td_io_u_lock(td);
- io_u->flags |= IO_U_F_FREE;
- io_u->flags &= ~IO_U_F_FREE_DEF;
-
- if (io_u->file)
+ if (io_u->file && !(io_u->flags & IO_U_F_FREE_DEF))
put_file_log(td, io_u->file);
-
io_u->file = NULL;
+ io_u->flags &= ~IO_U_F_FREE_DEF;
+ io_u->flags |= IO_U_F_FREE;
+
if (io_u->flags & IO_U_F_IN_CUR_DEPTH)
td->cur_depth--;
flist_del_init(&io_u->list);