fscache: Add a function for a cache backend to note an I/O error

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

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819598741.215744.891281275151382095.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163906901316.143852.15225412215771586528.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/163967100721.1823006.16435671567428949398.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/164021508840.640689.11902836226570620424.stgit@warthog.procyon.org.uk/

diff --git a/fs/fscache/cache.c b/fs/fscache/cache.c
index bbd102be91c4e2050cbeba776b1fdd8763e113d9..25eac61f1c2962e1c4ae905104f22b6d439e6f4e 100644 (file)
--- 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 a10b66ca3544ed80f0a560ad6ca50410ab42e718..936ef731bbc7ae45b8f2b3392e69af398d72b861 100644 (file)
--- 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);