[PATCH 16/64] fscache: Add a function for a cache backend to note an I/O error

From: David Howells
Date: Mon Nov 29 2021 - 09:29:15 EST


Add a function to the backend API to note an I/O error in a cache.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: linux-cachefs@xxxxxxxxxx
---

fs/fscache/cache.c | 20 ++++++++++++++++++++
include/linux/fscache-cache.h | 2 ++
2 files changed, 22 insertions(+)

diff --git a/fs/fscache/cache.c b/fs/fscache/cache.c
index bbd102be91c4..25eac61f1c29 100644
--- a/fs/fscache/cache.c
+++ b/fs/fscache/cache.c
@@ -321,6 +321,26 @@ void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_t
wake_up_var(&cache->n_accesses);
}

+/**
+ * fscache_io_error - Note a cache I/O error
+ * @cache: The record describing the cache
+ *
+ * Note that an I/O error occurred in a cache and that it should no longer be
+ * used for anything. This also reports the error into the kernel log.
+ *
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
+ * description.
+ */
+void fscache_io_error(struct fscache_cache *cache)
+{
+ if (fscache_set_cache_state_maybe(cache,
+ FSCACHE_CACHE_IS_ACTIVE,
+ FSCACHE_CACHE_GOT_IOERROR))
+ pr_err("Cache '%s' stopped due to I/O error\n",
+ cache->name);
+}
+EXPORT_SYMBOL(fscache_io_error);
+
/**
* fscache_withdraw_cache - Withdraw a cache from the active service
* @cache: The cache cookie
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index a10b66ca3544..936ef731bbc7 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -73,6 +73,8 @@ extern int fscache_add_cache(struct fscache_cache *cache,
extern void fscache_withdraw_cache(struct fscache_cache *cache);
extern void fscache_withdraw_volume(struct fscache_volume *volume);

+extern void fscache_io_error(struct fscache_cache *cache);
+
extern void fscache_end_volume_access(struct fscache_volume *volume,
struct fscache_cookie *cookie,
enum fscache_access_trace why);