The invalidate_remove() function has incomplete logic for handling write
hit bios after cache invalidation. It sets up the remapping for the
overwrite_bio but then drops it immediately without submission, causing
write operations to hang.
Fix by adding a new invalidate_committed() continuation that submits
the remapped writes to the cache origin after metadata commit completes,
while using the overwrite_endio hook to ensure proper completion
sequencing. This maintains existing coherency. Also improve error
handling in invalidate_complete() to preserve the original error status
instead of using bio_io_error() unconditionally.
Fixes: b29d4986d0da ("dm cache: significant rework to leverage
dm-bio-prison-v2")
Signed-off-by: Ming-Hung Tsai <[email protected]>
---
drivers/md/dm-cache-target.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index ac9901033073..8b62fe69722d 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1467,8 +1467,14 @@ static void invalidate_complete(struct
dm_cache_migration *mg, bool success)
free_prison_cell(cache, mg->cell);
}
- if (!success && mg->overwrite_bio)
- bio_io_error(mg->overwrite_bio);
+ if (mg->overwrite_bio) {
+ // Set generic error if the bio hasn't been issued yet,
+ // e.g., invalidation or metadata commit failed before bio
+ // submission. Otherwise preserve the bio's own error status.
+ if (!success && !mg->overwrite_bio->bi_status)
+ mg->overwrite_bio->bi_status = BLK_STS_IOERR;
+ bio_endio(mg->overwrite_bio);
+ }
free_migration(mg);
defer_bios(cache, &bios);
@@ -1508,6 +1514,22 @@ static int invalidate_cblock(struct cache *cache,
dm_cblock_t cblock)
return r;
}
+static void invalidate_committed(struct work_struct *ws)
+{
+ struct dm_cache_migration *mg = ws_to_mg(ws);
+ struct cache *cache = mg->cache;
+ struct bio *bio = mg->overwrite_bio;
+ struct per_bio_data *pb = get_per_bio_data(bio);
+
+ if (mg->k.input)
+ invalidate_complete(mg, false);
+
+ init_continuation(&mg->k, invalidate_completed);
+ remap_to_origin_clear_discard(cache, bio, mg->invalidate_oblock);
+ dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg);
+ dm_submit_bio_remap(bio, NULL);
+}
+
static void invalidate_remove(struct work_struct *ws)
{
int r;
@@ -1520,10 +1542,8 @@ static void invalidate_remove(struct work_struct *ws)
return;
}
- init_continuation(&mg->k, invalidate_completed);
+ init_continuation(&mg->k, invalidate_committed);
continue_after_commit(&cache->committer, &mg->k);
- remap_to_origin_clear_discard(cache, mg->overwrite_bio,
mg->invalidate_oblock);
- mg->overwrite_bio = NULL;
schedule_commit(&cache->committer);
}
--
2.49.0
