FS-Cache: Handle a new operation submitted against a killed object

Reject new operations that are being submitted against an object if that
object has failed its lookup or creation states or has been killed by the
cache backend for some other reason, such as having been culled.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steve Dickson <steved@redhat.com>
Acked-by: Jeff Layton <jeff.layton@primarydata.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 12bb468bf0ae..9b79fc9a1464 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -610,6 +610,8 @@ static const struct fscache_state *fscache_lookup_failure(struct fscache_object
         object->cache->ops->lookup_complete(object);
         fscache_stat_d(&fscache_n_cop_lookup_complete);
 
+        set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags);
+
         cookie = object->cookie;
         set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
         if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index dec6defe3be3..18658fffbba1 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -176,6 +176,9 @@ int fscache_submit_exclusive_op(struct fscache_object *object,
                 list_add_tail(&op->pend_link, &object->pending_ops);
                 fscache_stat(&fscache_n_op_pend);
                 ret = 0;
+        } else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
+                op->state = FSCACHE_OP_ST_CANCELLED;
+                ret = -ENOBUFS;
         } else {
                 fscache_report_unexpected_submission(object, op, ostate);
                 op->state = FSCACHE_OP_ST_CANCELLED;
@@ -249,6 +252,9 @@ int fscache_submit_op(struct fscache_object *object,
                 list_add_tail(&op->pend_link, &object->pending_ops);
                 fscache_stat(&fscache_n_op_pend);
                 ret = 0;
+        } else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
+                op->state = FSCACHE_OP_ST_CANCELLED;
+                ret = -ENOBUFS;
         } else {
                 fscache_report_unexpected_submission(object, op, ostate);
                 ASSERT(!fscache_object_is_active(object));