fscache: Maintain a catalogue of allocated cookies
Maintain a catalogue of allocated cookies so that cookie collisions can be
handled properly. For the moment, this just involves printing a warning
and returning a NULL cookie to the caller of fscache_acquire_cookie(), but
in future it might make sense to wait for the old cookie to finish being
cleaned up.
This requires the cookie key to be stored attached to the cookie so that we
still have the key available if the netfs relinquishes the cookie. This is
done by an earlier patch.
The catalogue also renders redundant fscache_netfs_list (used for checking
for duplicates), so that can be removed.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index eb38f39..84b90a7 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -22,6 +22,7 @@
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
+#include <linux/list_bl.h>
#if defined(CONFIG_FSCACHE) || defined(CONFIG_FSCACHE_MODULE)
#define fscache_available() (1)
@@ -124,7 +125,6 @@ struct fscache_netfs {
uint32_t version; /* indexing version */
const char *name; /* filesystem name */
struct fscache_cookie *primary_index;
- struct list_head link; /* internal link */
};
/*
@@ -143,6 +143,7 @@ struct fscache_cookie {
struct hlist_head backing_objects; /* object(s) backing this file/index */
const struct fscache_cookie_def *def; /* definition */
struct fscache_cookie *parent; /* parent of this entry */
+ struct hlist_bl_node hash_link; /* Link in hash table */
void *netfs_data; /* back pointer to netfs */
struct radix_tree_root stores; /* pages to be stored on this cookie */
#define FSCACHE_COOKIE_PENDING_TAG 0 /* pages tag: pending write to cache */
@@ -156,11 +157,14 @@ struct fscache_cookie {
#define FSCACHE_COOKIE_RELINQUISHED 4 /* T if cookie has been relinquished */
#define FSCACHE_COOKIE_ENABLED 5 /* T if cookie is enabled */
#define FSCACHE_COOKIE_ENABLEMENT_LOCK 6 /* T if cookie is being en/disabled */
-#define FSCACHE_COOKIE_AUX_UPDATED 7 /* T if the auxiliary data was updated */
+#define FSCACHE_COOKIE_AUX_UPDATED 8 /* T if the auxiliary data was updated */
+#define FSCACHE_COOKIE_ACQUIRED 9 /* T if cookie is in use */
+#define FSCACHE_COOKIE_RELINQUISHING 10 /* T if cookie is being relinquished */
u8 type; /* Type of object */
u8 key_len; /* Length of index key */
u8 aux_len; /* Length of auxiliary data */
+ u32 key_hash; /* Hash of parent, type, key, len */
union {
void *key; /* Index key */
u8 inline_key[16]; /* - If the key is short enough */