bcachefs: BTREE_TRIGGER_TRANSACTIONAL

New flag so that triggers can distinguish whether we're running
transactional or atomic triggers (or gc) - unifying the callbacks.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/bkey_methods.h b/fs/bcachefs/bkey_methods.h
index 8960200550977964ef5676e47ab12819ec198275..d8f42ba1cd0f3b502872362b5e8480a0eb53fcbd 100644 (file)
--- a/fs/bcachefs/bkey_methods.h
+++ b/fs/bcachefs/bkey_methods.h
@@ -95,11 +95,10 @@ enum btree_update_flags {
        __BTREE_UPDATE_NOJOURNAL,
        __BTREE_UPDATE_KEY_CACHE_RECLAIM,
 
-       __BTREE_TRIGGER_NORUN,          /* Don't run triggers at all */
-
+       __BTREE_TRIGGER_NORUN,
+       __BTREE_TRIGGER_TRANSACTIONAL,
        __BTREE_TRIGGER_INSERT,
        __BTREE_TRIGGER_OVERWRITE,
-
        __BTREE_TRIGGER_GC,
        __BTREE_TRIGGER_BUCKET_INVALIDATE,
 };
@@ -108,12 +107,31 @@ enum btree_update_flags {
 #define BTREE_UPDATE_NOJOURNAL         (1U << __BTREE_UPDATE_NOJOURNAL)
 #define BTREE_UPDATE_KEY_CACHE_RECLAIM (1U << __BTREE_UPDATE_KEY_CACHE_RECLAIM)
 
+/* Don't run triggers at all */
 #define BTREE_TRIGGER_NORUN            (1U << __BTREE_TRIGGER_NORUN)
 
+/*
+ * If set, we're running transactional triggers as part of a transaction commit:
+ * triggers may generate new updates
+ *
+ * If cleared, and either BTREE_TRIGGER_INSERT|BTREE_TRIGGER_OVERWRITE are set,
+ * we're running atomic triggers during a transaction commit: we have our
+ * journal reservation, we're holding btree node write locks, and we know the
+ * transaction is going to commit (returning an error here is a fatal error,
+ * causing us to go emergency read-only)
+ */
+#define BTREE_TRIGGER_TRANSACTIONAL    (1U << __BTREE_TRIGGER_TRANSACTIONAL)
+
+/* @new is entering the btree */
 #define BTREE_TRIGGER_INSERT           (1U << __BTREE_TRIGGER_INSERT)
+
+/* @old is leaving the btree */
 #define BTREE_TRIGGER_OVERWRITE                (1U << __BTREE_TRIGGER_OVERWRITE)
 
+/* We're in gc/fsck: running triggers to recalculate e.g. disk usage */
 #define BTREE_TRIGGER_GC               (1U << __BTREE_TRIGGER_GC)
+
+/* signal from bucket invalidate path to alloc trigger */
 #define BTREE_TRIGGER_BUCKET_INVALIDATE        (1U << __BTREE_TRIGGER_BUCKET_INVALIDATE)
 
 static inline int bch2_trans_mark_key(struct btree_trans *trans,
@@ -124,7 +142,7 @@ static inline int bch2_trans_mark_key(struct btree_trans *trans,
        const struct bkey_ops *ops = bch2_bkey_type_ops(old.k->type ?: new.k->type);
 
        return ops->trans_trigger
-               ? ops->trans_trigger(trans, btree_id, level, old, new, flags)
+               ? ops->trans_trigger(trans, btree_id, level, old, new, flags|BTREE_TRIGGER_TRANSACTIONAL)
                : 0;
 }