lightnvm: pblk: GC error handling

Currently when there is an IO error (or similar) on GC read path, pblk
still move the line, which was currently under GC process to free state.
Such a behaviour can lead to silent data mismatch issue.

With this patch, the line which was under GC process on which some IO
errors occurred, will be putted back to closed state (instead of free
state as it was without this patch) and the L2P mapping for such a
failed sectors will not be updated.

Then in case of any user IOs to such a failed sectors, pblk would be
able to return at least real IO error instead of stale data as it is
right now.

Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
index 38e26fe23138..73be3a0311ff 100644
--- a/drivers/lightnvm/pblk-core.c
+++ b/drivers/lightnvm/pblk-core.c
@@ -1703,6 +1703,14 @@ static void __pblk_line_put(struct pblk *pblk, struct pblk_line *line)
 
 	spin_lock(&line->lock);
 	WARN_ON(line->state != PBLK_LINESTATE_GC);
+	if (line->w_err_gc->has_gc_err) {
+		spin_unlock(&line->lock);
+		pblk_err(pblk, "line %d had errors during GC\n", line->id);
+		pblk_put_line_back(pblk, line);
+		line->w_err_gc->has_gc_err = 0;
+		return;
+	}
+
 	line->state = PBLK_LINESTATE_FREE;
 	trace_pblk_line_state(pblk_disk_name(pblk), line->id,
 					line->state);