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
On Tue, Oct 25, 2011 at 1:23 PM, Steven Lang <tirea@xxxxxxxxxx> wrote:
> 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.
>
> 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 @@ void put_io_u(struct thread_data *td, struct io_u *io_u)
> {
> 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);
> diff --git a/verify.c b/verify.c
> index c450e88..68ee60f 100644
> --- a/verify.c
> +++ b/verify.c
> @@ -599,10 +599,8 @@ int verify_io_u_async(struct thread_data *td,
> struct io_u *io_u)
> if (io_u->file)
> put_file_log(td, io_u->file);
>
> - io_u->file = NULL;
> -
> pthread_mutex_lock(&td->io_u_lock);
> -
> +
> if (io_u->flags & IO_U_F_IN_CUR_DEPTH) {
> td->cur_depth--;
> io_u->flags &= ~IO_U_F_IN_CUR_DEPTH;
>
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