jffs2: Erase pending blocks in GC pass, avoid invalid -EIO return

jffs2_garbage_collect_pass() would previously return -EAGAIN if it
couldn't find anything to garbage collect from, and there were blocks on
the erase_pending_list. If the blocks were actually in the process of
being erased, though, then they wouldn't be on that list. Check for
nr_erasing_blocks being non-zero instead.

Fix jffs2_reserve_space() to wait for the in-progress erases to
complete, when jffs2_garbage_collect_pass() returns -EAGAIN.

And fix jffs2_erase_succeeded() to actually wake up the erase_wait wq
that jffs2_reserve_space() is now using.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c
index 191359dde4e1..08e2c69fc147 100644
--- a/fs/jffs2/nodemgmt.c
+++ b/fs/jffs2/nodemgmt.c
@@ -116,9 +116,21 @@ int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
 
 			ret = jffs2_garbage_collect_pass(c);
 
-			if (ret == -EAGAIN)
-				jffs2_erase_pending_blocks(c, 1);
-			else if (ret)
+			if (ret == -EAGAIN) {
+				spin_lock(&c->erase_completion_lock);
+				if (c->nr_erasing_blocks &&
+				    list_empty(&c->erase_pending_list) &&
+				    list_empty(&c->erase_complete_list)) {
+					DECLARE_WAITQUEUE(wait, current);
+					set_current_state(TASK_UNINTERRUPTIBLE);
+					add_wait_queue(&c->erase_wait, &wait);
+					D1(printk(KERN_DEBUG "%s waiting for erase to complete\n", __func__));
+					spin_unlock(&c->erase_completion_lock);
+
+					schedule();
+				} else
+					spin_unlock(&c->erase_completion_lock);
+			} else if (ret)
 				return ret;
 
 			cond_resched();