[PATCH 14/21] cache: return results of a cache flush

Darrick J. Wong
2025-09-16T00:54:18Z

Modify cache_flush to return whether or not there were errors whilst
flushing the cache.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
lib/support/cache.h | 4 ++--
lib/support/cache.c | 11 +++++++----
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/support/cache.h b/lib/support/cache.h
index e8f1c82ef7869c..8d39ca5c02a285 100644
--- a/lib/support/cache.h
+++ b/lib/support/cache.h
@@ -58,7 +58,7 @@ typedef void *cache_key_t;

typedef void (*cache_walk_t)(struct cache *c, struct cache_node *cn, void *d);
typedef struct cache_node * (*cache_node_alloc_t)(struct cache *c, cache_key_t k);
-typedef int (*cache_node_flush_t)(struct cache *c, struct cache_node *cn);
+typedef bool (*cache_node_flush_t)(struct cache *c, struct cache_node *cn);
typedef void (*cache_node_relse_t)(struct cache *c, struct cache_node *cn);
typedef unsigned int (*cache_node_hash_t)(cache_key_t, unsigned int,
unsigned int);
@@ -132,7 +132,7 @@ int cache_init(int flags, unsigned int size,
void cache_destroy(struct cache *cache);
void cache_walk(struct cache *cache, cache_walk_t fn, void *data);
void cache_purge(struct cache *);
-void cache_flush(struct cache *);
+bool cache_flush(struct cache *cache);

int cache_node_get(struct cache *, cache_key_t, struct cache_node **);
void cache_node_put(struct cache *, struct cache_node *);
diff --git a/lib/support/cache.c b/lib/support/cache.c
index 49568ffa6de2e4..fa07b4ad8222d2 100644
--- a/lib/support/cache.c
+++ b/lib/support/cache.c
@@ -631,18 +631,19 @@ cache_purge(
}

/*
- * Flush all nodes in the cache to disk.
+ * Flush all nodes in the cache to disk. Returns true if the flush succeeded.
*/
-void
+bool
cache_flush(
struct cache *cache)
{
struct cache_hash *hash;
struct cache_node *node;
int i;
+ bool still_dirty = false;

if (!cache->flush)
- return;
+ return true;

for (i = 0; i < cache->c_hashsize; i++) {
hash = &cache->c_hash[i];
@@ -650,11 +651,13 @@ cache_flush(
pthread_mutex_lock(&hash->ch_mutex);
list_for_each_entry(node, &hash->ch_list, cn_hash) {
pthread_mutex_lock(&node->cn_mutex);
- cache->flush(cache, node);
+ still_dirty |= cache->flush(cache, node);
pthread_mutex_unlock(&node->cn_mutex);
}
pthread_mutex_unlock(&hash->ch_mutex);
}
+
+ return !still_dirty;
}

#define HASH_REPORT (3 * HASH_CACHE_RATIO)