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-rw-r--r--Documentation/filesystems/caching/backend-api.txt23
-rw-r--r--Documentation/filesystems/caching/fscache.txt4
-rw-r--r--fs/cachefiles/internal.h1
-rw-r--r--fs/cachefiles/namei.c33
-rw-r--r--fs/fscache/internal.h5
-rw-r--r--fs/fscache/object.c47
-rw-r--r--fs/fscache/stats.c10
-rw-r--r--include/linux/fscache-cache.h12
8 files changed, 122 insertions, 13 deletions
diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt
index 277d1e8..c0bd567 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.txt
@@ -676,6 +676,29 @@ FS-Cache provides some utilities that a cache backend may make use of:
as possible.
+ (*) Indicate that a stale object was found and discarded:
+
+ void fscache_object_retrying_stale(struct fscache_object *object);
+
+ This is called to indicate that the lookup procedure found an object in
+ the cache that the netfs decided was stale. The object has been
+ discarded from the cache and the lookup will be performed again.
+
+
+ (*) Indicate that the caching backend killed an object:
+
+ void fscache_object_mark_killed(struct fscache_object *object,
+ enum fscache_why_object_killed why);
+
+ This is called to indicate that the cache backend preemptively killed an
+ object. The why parameter should be set to indicate the reason:
+
+ FSCACHE_OBJECT_IS_STALE - the object was stale and needs discarding.
+ FSCACHE_OBJECT_NO_SPACE - there was insufficient cache space
+ FSCACHE_OBJECT_WAS_RETIRED - the object was retired when relinquished.
+ FSCACHE_OBJECT_WAS_CULLED - the object was culled to make space.
+
+
(*) Get and release references on a retrieval record:
void fscache_get_retrieval(struct fscache_retrieval *op);
diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt
index 770267a..66fa7fb 100644
--- a/Documentation/filesystems/caching/fscache.txt
+++ b/Documentation/filesystems/caching/fscache.txt
@@ -303,6 +303,10 @@ proc files.
wrp=N Number of in-progress write_page() cache ops
ucp=N Number of in-progress uncache_page() cache ops
dsp=N Number of in-progress dissociate_pages() cache ops
+ CacheEv nsp=N Number of object lookups/creations rejected due to lack of space
+ stl=N Number of stale objects deleted
+ rtr=N Number of objects retired when relinquished
+ cul=N Number of objects culled
(*) /proc/fs/fscache/histogram
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 8c52472..aecd085 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -43,7 +43,6 @@ struct cachefiles_object {
loff_t i_size; /* object size */
unsigned long flags;
#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
-#define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */
atomic_t usage; /* object usage count */
uint8_t type; /* object type */
uint8_t new; /* T if object new */
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 7f8e83f..1d60195 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -97,7 +97,8 @@ static noinline void cachefiles_printk_object(struct cachefiles_object *object,
* call vfs_unlink(), vfs_rmdir() or vfs_rename()
*/
static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
- struct dentry *dentry)
+ struct dentry *dentry,
+ enum fscache_why_object_killed why)
{
struct cachefiles_object *object;
struct rb_node *p;
@@ -132,8 +133,9 @@ found_dentry:
pr_err("\n");
pr_err("Error: Can't preemptively bury live object\n");
cachefiles_printk_object(object, NULL);
- } else if (test_and_set_bit(CACHEFILES_OBJECT_BURIED, &object->flags)) {
- pr_err("Error: Object already preemptively buried\n");
+ } else {
+ if (why != FSCACHE_OBJECT_IS_STALE)
+ fscache_object_mark_killed(&object->fscache, why);
}
write_unlock(&cache->active_lock);
@@ -265,7 +267,8 @@ requeue:
static int cachefiles_bury_object(struct cachefiles_cache *cache,
struct dentry *dir,
struct dentry *rep,
- bool preemptive)
+ bool preemptive,
+ enum fscache_why_object_killed why)
{
struct dentry *grave, *trap;
struct path path, path_to_graveyard;
@@ -289,7 +292,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
ret = vfs_unlink(dir->d_inode, rep, NULL);
if (preemptive)
- cachefiles_mark_object_buried(cache, rep);
+ cachefiles_mark_object_buried(cache, rep, why);
}
mutex_unlock(&dir->d_inode->i_mutex);
@@ -394,7 +397,7 @@ try_again:
"Rename failed with error %d", ret);
if (preemptive)
- cachefiles_mark_object_buried(cache, rep);
+ cachefiles_mark_object_buried(cache, rep, why);
}
unlock_rename(cache->graveyard, dir);
@@ -422,7 +425,7 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT);
- if (test_bit(CACHEFILES_OBJECT_BURIED, &object->flags)) {
+ if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) {
/* object allocation for the same key preemptively deleted this
* object's file so that it could create its own file */
_debug("object preemptively buried");
@@ -433,7 +436,8 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,
* may have been renamed */
if (dir == object->dentry->d_parent) {
ret = cachefiles_bury_object(cache, dir,
- object->dentry, false);
+ object->dentry, false,
+ FSCACHE_OBJECT_WAS_RETIRED);
} else {
/* it got moved, presumably by cachefilesd culling it,
* so it's no longer in the key path and we can ignore
@@ -522,7 +526,7 @@ lookup_again:
if (!next->d_inode) {
ret = cachefiles_has_space(cache, 1, 0);
if (ret < 0)
- goto create_error;
+ goto no_space_error;
path.dentry = dir;
ret = security_path_mkdir(&path, next, 0);
@@ -551,7 +555,7 @@ lookup_again:
if (!next->d_inode) {
ret = cachefiles_has_space(cache, 1, 0);
if (ret < 0)
- goto create_error;
+ goto no_space_error;
path.dentry = dir;
ret = security_path_mknod(&path, next, S_IFREG, 0);
@@ -602,7 +606,8 @@ lookup_again:
* mutex) */
object->dentry = NULL;
- ret = cachefiles_bury_object(cache, dir, next, true);
+ ret = cachefiles_bury_object(cache, dir, next, true,
+ FSCACHE_OBJECT_IS_STALE);
dput(next);
next = NULL;
@@ -610,6 +615,7 @@ lookup_again:
goto delete_error;
_debug("redo lookup");
+ fscache_object_retrying_stale(&object->fscache);
goto lookup_again;
}
}
@@ -662,6 +668,8 @@ lookup_again:
_leave(" = 0 [%lu]", object->dentry->d_inode->i_ino);
return 0;
+no_space_error:
+ fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE);
create_error:
_debug("create error %d", ret);
if (ret == -EIO)
@@ -927,7 +935,8 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
/* actually remove the victim (drops the dir mutex) */
_debug("bury");
- ret = cachefiles_bury_object(cache, dir, victim, false);
+ ret = cachefiles_bury_object(cache, dir, victim, false,
+ FSCACHE_OBJECT_WAS_CULLED);
if (ret < 0)
goto error;
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 7872a62..3063a58 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -271,6 +271,11 @@ extern atomic_t fscache_n_cop_write_page;
extern atomic_t fscache_n_cop_uncache_page;
extern atomic_t fscache_n_cop_dissociate_pages;
+extern atomic_t fscache_n_cache_no_space_reject;
+extern atomic_t fscache_n_cache_stale_objects;
+extern atomic_t fscache_n_cache_retired_objects;
+extern atomic_t fscache_n_cache_culled_objects;
+
static inline void fscache_stat(atomic_t *stat)
{
atomic_inc(stat);
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index da032da..12bb468 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -1016,3 +1016,50 @@ static const struct fscache_state *fscache_update_object(struct fscache_object *
_leave("");
return transit_to(WAIT_FOR_CMD);
}
+
+/**
+ * fscache_object_retrying_stale - Note retrying stale object
+ * @object: The object that will be retried
+ *
+ * Note that an object lookup found an on-disk object that was adjudged to be
+ * stale and has been deleted. The lookup will be retried.
+ */
+void fscache_object_retrying_stale(struct fscache_object *object)
+{
+ fscache_stat(&fscache_n_cache_no_space_reject);
+}
+EXPORT_SYMBOL(fscache_object_retrying_stale);
+
+/**
+ * fscache_object_mark_killed - Note that an object was killed
+ * @object: The object that was culled
+ * @why: The reason the object was killed.
+ *
+ * Note that an object was killed. Returns true if the object was
+ * already marked killed, false if it wasn't.
+ */
+void fscache_object_mark_killed(struct fscache_object *object,
+ enum fscache_why_object_killed why)
+{
+ if (test_and_set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags)) {
+ pr_err("Error: Object already killed by cache [%s]\n",
+ object->cache->identifier);
+ return;
+ }
+
+ switch (why) {
+ case FSCACHE_OBJECT_NO_SPACE:
+ fscache_stat(&fscache_n_cache_no_space_reject);
+ break;
+ case FSCACHE_OBJECT_IS_STALE:
+ fscache_stat(&fscache_n_cache_stale_objects);
+ break;
+ case FSCACHE_OBJECT_WAS_RETIRED:
+ fscache_stat(&fscache_n_cache_retired_objects);
+ break;
+ case FSCACHE_OBJECT_WAS_CULLED:
+ fscache_stat(&fscache_n_cache_culled_objects);
+ break;
+ }
+}
+EXPORT_SYMBOL(fscache_object_mark_killed);
diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c
index 40d13c7..3a722e8 100644
--- a/fs/fscache/stats.c
+++ b/fs/fscache/stats.c
@@ -130,6 +130,11 @@ atomic_t fscache_n_cop_write_page;
atomic_t fscache_n_cop_uncache_page;
atomic_t fscache_n_cop_dissociate_pages;
+atomic_t fscache_n_cache_no_space_reject;
+atomic_t fscache_n_cache_stale_objects;
+atomic_t fscache_n_cache_retired_objects;
+atomic_t fscache_n_cache_culled_objects;
+
/*
* display the general statistics
*/
@@ -271,6 +276,11 @@ static int fscache_stats_show(struct seq_file *m, void *v)
atomic_read(&fscache_n_cop_write_page),
atomic_read(&fscache_n_cop_uncache_page),
atomic_read(&fscache_n_cop_dissociate_pages));
+ seq_printf(m, "CacheEv: nsp=%d stl=%d rtr=%d cul=%d\n",
+ atomic_read(&fscache_n_cache_no_space_reject),
+ atomic_read(&fscache_n_cache_stale_objects),
+ atomic_read(&fscache_n_cache_retired_objects),
+ atomic_read(&fscache_n_cache_culled_objects));
return 0;
}
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 7714849..c9dafda 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -371,6 +371,7 @@ struct fscache_object {
#define FSCACHE_OBJECT_IS_LOOKED_UP 4 /* T if object has been looked up */
#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */
#define FSCACHE_OBJECT_RETIRED 6 /* T if object was retired on relinquishment */
+#define FSCACHE_OBJECT_KILLED_BY_CACHE 7 /* T if object was killed by the cache */
struct list_head cache_link; /* link in cache->object_list */
struct hlist_node cookie_link; /* link in cookie->backing_objects */
@@ -551,4 +552,15 @@ extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data,
uint16_t datalen);
+extern void fscache_object_retrying_stale(struct fscache_object *object);
+
+enum fscache_why_object_killed {
+ FSCACHE_OBJECT_IS_STALE,
+ FSCACHE_OBJECT_NO_SPACE,
+ FSCACHE_OBJECT_WAS_RETIRED,
+ FSCACHE_OBJECT_WAS_CULLED,
+};
+extern void fscache_object_mark_killed(struct fscache_object *object,
+ enum fscache_why_object_killed why);
+
#endif /* _LINUX_FSCACHE_CACHE_H */
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