gfs2: initialize transaction tr_ailX_lists earlier

commit cbcc89b6 upstream.

Since transactions may be freed shortly after they're created, before
a log_flush occurs, we need to initialize their ail1 and ail2 lists
earlier. Before this patch, the ail1 list was initialized in gfs2_log_flush().
This moves the initialization to the point when the transaction is first
created.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/gfs2/glops.c

@@ -89,6 +89,8 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 	memset(&tr, 0, sizeof(tr));
 	INIT_LIST_HEAD(&tr.tr_buf);
 	INIT_LIST_HEAD(&tr.tr_databuf);
+	INIT_LIST_HEAD(&tr.tr_ail1_list);
+	INIT_LIST_HEAD(&tr.tr_ail2_list);
 	tr.tr_revokes = atomic_read(&gl->gl_ail_count);
 
 	if (!tr.tr_revokes)

fs/gfs2/log.c

@@ -806,8 +806,6 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
 	tr = sdp->sd_log_tr;
 	if (tr) {
 		sdp->sd_log_tr = NULL;
-		INIT_LIST_HEAD(&tr->tr_ail1_list);
-		INIT_LIST_HEAD(&tr->tr_ail2_list);
 		tr->tr_first = sdp->sd_log_flush_head;
 		if (unlikely (state == SFS_FROZEN))
 			gfs2_assert_withdraw(sdp, !tr->tr_num_buf_new && !tr->tr_num_databuf_new);

fs/gfs2/trans.c

@@ -56,6 +56,8 @@ int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
 						   sizeof(u64));
 	INIT_LIST_HEAD(&tr->tr_databuf);
 	INIT_LIST_HEAD(&tr->tr_buf);
+	INIT_LIST_HEAD(&tr->tr_ail1_list);
+	INIT_LIST_HEAD(&tr->tr_ail2_list);
 
 	sb_start_intwrite(sdp->sd_vfs);