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-rw-r--r--fs/fscache/Makefile1
-rw-r--r--fs/fscache/cookie.c497
-rw-r--r--fs/fscache/internal.h23
-rw-r--r--fs/fscache/main.c12
-rw-r--r--fs/fscache/proc.c4
-rw-r--r--fs/fscache/stats.c28
-rw-r--r--include/linux/fscache-cache.h22
-rw-r--r--include/linux/fscache.h134
-rw-r--r--include/trace/events/fscache.h111
9 files changed, 831 insertions, 1 deletions
diff --git a/fs/fscache/Makefile b/fs/fscache/Makefile
index bb5282ae682f..bcc79615f93a 100644
--- a/fs/fscache/Makefile
+++ b/fs/fscache/Makefile
@@ -5,6 +5,7 @@
fscache-y := \
cache.o \
+ cookie.o \
main.o \
volume.o
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
new file mode 100644
index 000000000000..438b0098aa73
--- /dev/null
+++ b/fs/fscache/cookie.c
@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* netfs cookie management
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * See Documentation/filesystems/caching/netfs-api.rst for more information on
+ * the netfs API.
+ */
+
+#define FSCACHE_DEBUG_LEVEL COOKIE
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+struct kmem_cache *fscache_cookie_jar;
+
+static void fscache_drop_cookie(struct fscache_cookie *cookie);
+
+#define fscache_cookie_hash_shift 15
+static struct hlist_bl_head fscache_cookie_hash[1 << fscache_cookie_hash_shift];
+static LIST_HEAD(fscache_cookies);
+static DEFINE_RWLOCK(fscache_cookies_lock);
+static const char fscache_cookie_states[FSCACHE_COOKIE_STATE__NR] = "-LCAFWRD";
+
+void fscache_print_cookie(struct fscache_cookie *cookie, char prefix)
+{
+ const u8 *k;
+
+ pr_err("%c-cookie c=%08x [fl=%lx na=%u nA=%u s=%c]\n",
+ prefix,
+ cookie->debug_id,
+ cookie->flags,
+ atomic_read(&cookie->n_active),
+ atomic_read(&cookie->n_accesses),
+ fscache_cookie_states[cookie->state]);
+ pr_err("%c-cookie V=%08x [%s]\n",
+ prefix,
+ cookie->volume->debug_id,
+ cookie->volume->key);
+
+ k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
+ cookie->inline_key : cookie->key;
+ pr_err("%c-key=[%u] '%*phN'\n", prefix, cookie->key_len, cookie->key_len, k);
+}
+
+static void fscache_free_cookie(struct fscache_cookie *cookie)
+{
+ if (WARN_ON_ONCE(test_bit(FSCACHE_COOKIE_IS_HASHED, &cookie->flags))) {
+ fscache_print_cookie(cookie, 'F');
+ return;
+ }
+
+ write_lock(&fscache_cookies_lock);
+ list_del(&cookie->proc_link);
+ write_unlock(&fscache_cookies_lock);
+ if (cookie->aux_len > sizeof(cookie->inline_aux))
+ kfree(cookie->aux);
+ if (cookie->key_len > sizeof(cookie->inline_key))
+ kfree(cookie->key);
+ fscache_stat_d(&fscache_n_cookies);
+ kmem_cache_free(fscache_cookie_jar, cookie);
+}
+
+static inline void wake_up_cookie_state(struct fscache_cookie *cookie)
+{
+ /* Use a barrier to ensure that waiters see the state variable
+ * change, as spin_unlock doesn't guarantee a barrier.
+ *
+ * See comments over wake_up_bit() and waitqueue_active().
+ */
+ smp_mb();
+ wake_up_var(&cookie->state);
+}
+
+static void __fscache_set_cookie_state(struct fscache_cookie *cookie,
+ enum fscache_cookie_state state)
+{
+ cookie->state = state;
+}
+
+/*
+ * Change the state a cookie is at and wake up anyone waiting for that - but
+ * only if the cookie isn't already marked as being in a cleanup state.
+ */
+void fscache_set_cookie_state(struct fscache_cookie *cookie,
+ enum fscache_cookie_state state)
+{
+ bool changed = false;
+
+ spin_lock(&cookie->lock);
+ switch (cookie->state) {
+ case FSCACHE_COOKIE_STATE_RELINQUISHING:
+ break;
+ default:
+ __fscache_set_cookie_state(cookie, state);
+ changed = true;
+ break;
+ }
+ spin_unlock(&cookie->lock);
+ if (changed)
+ wake_up_cookie_state(cookie);
+}
+EXPORT_SYMBOL(fscache_set_cookie_state);
+
+/*
+ * Set the index key in a cookie. The cookie struct has space for a 16-byte
+ * key plus length and hash, but if that's not big enough, it's instead a
+ * pointer to a buffer containing 3 bytes of hash, 1 byte of length and then
+ * the key data.
+ */
+static int fscache_set_key(struct fscache_cookie *cookie,
+ const void *index_key, size_t index_key_len)
+{
+ void *buf;
+ size_t buf_size;
+
+ buf_size = round_up(index_key_len, sizeof(__le32));
+
+ if (index_key_len > sizeof(cookie->inline_key)) {
+ buf = kzalloc(buf_size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ cookie->key = buf;
+ } else {
+ buf = cookie->inline_key;
+ }
+
+ memcpy(buf, index_key, index_key_len);
+ cookie->key_hash = fscache_hash(cookie->volume->key_hash,
+ buf, buf_size);
+ return 0;
+}
+
+static bool fscache_cookie_same(const struct fscache_cookie *a,
+ const struct fscache_cookie *b)
+{
+ const void *ka, *kb;
+
+ if (a->key_hash != b->key_hash ||
+ a->volume != b->volume ||
+ a->key_len != b->key_len)
+ return false;
+
+ if (a->key_len <= sizeof(a->inline_key)) {
+ ka = &a->inline_key;
+ kb = &b->inline_key;
+ } else {
+ ka = a->key;
+ kb = b->key;
+ }
+ return memcmp(ka, kb, a->key_len) == 0;
+}
+
+static atomic_t fscache_cookie_debug_id = ATOMIC_INIT(1);
+
+/*
+ * Allocate a cookie.
+ */
+static struct fscache_cookie *fscache_alloc_cookie(
+ struct fscache_volume *volume,
+ u8 advice,
+ const void *index_key, size_t index_key_len,
+ const void *aux_data, size_t aux_data_len,
+ loff_t object_size)
+{
+ struct fscache_cookie *cookie;
+
+ /* allocate and initialise a cookie */
+ cookie = kmem_cache_zalloc(fscache_cookie_jar, GFP_KERNEL);
+ if (!cookie)
+ return NULL;
+ fscache_stat(&fscache_n_cookies);
+
+ cookie->volume = volume;
+ cookie->advice = advice;
+ cookie->key_len = index_key_len;
+ cookie->aux_len = aux_data_len;
+ cookie->object_size = object_size;
+ if (object_size == 0)
+ __set_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);
+
+ if (fscache_set_key(cookie, index_key, index_key_len) < 0)
+ goto nomem;
+
+ if (cookie->aux_len <= sizeof(cookie->inline_aux)) {
+ memcpy(cookie->inline_aux, aux_data, cookie->aux_len);
+ } else {
+ cookie->aux = kmemdup(aux_data, cookie->aux_len, GFP_KERNEL);
+ if (!cookie->aux)
+ goto nomem;
+ }
+
+ refcount_set(&cookie->ref, 1);
+ cookie->debug_id = atomic_inc_return(&fscache_cookie_debug_id);
+ cookie->state = FSCACHE_COOKIE_STATE_QUIESCENT;
+ spin_lock_init(&cookie->lock);
+ INIT_LIST_HEAD(&cookie->commit_link);
+ INIT_WORK(&cookie->work, NULL /* PLACEHOLDER */);
+
+ write_lock(&fscache_cookies_lock);
+ list_add_tail(&cookie->proc_link, &fscache_cookies);
+ write_unlock(&fscache_cookies_lock);
+ fscache_see_cookie(cookie, fscache_cookie_new_acquire);
+ return cookie;
+
+nomem:
+ fscache_free_cookie(cookie);
+ return NULL;
+}
+
+static void fscache_wait_on_collision(struct fscache_cookie *candidate,
+ struct fscache_cookie *wait_for)
+{
+ enum fscache_cookie_state *statep = &wait_for->state;
+
+ wait_var_event_timeout(statep, READ_ONCE(*statep) == FSCACHE_COOKIE_STATE_DROPPED,
+ 20 * HZ);
+ if (READ_ONCE(*statep) != FSCACHE_COOKIE_STATE_DROPPED) {
+ pr_notice("Potential collision c=%08x old: c=%08x",
+ candidate->debug_id, wait_for->debug_id);
+ wait_var_event(statep, READ_ONCE(*statep) == FSCACHE_COOKIE_STATE_DROPPED);
+ }
+}
+
+/*
+ * Attempt to insert the new cookie into the hash. If there's a collision, we
+ * wait for the old cookie to complete if it's being relinquished and an error
+ * otherwise.
+ */
+static bool fscache_hash_cookie(struct fscache_cookie *candidate)
+{
+ struct fscache_cookie *cursor, *wait_for = NULL;
+ struct hlist_bl_head *h;
+ struct hlist_bl_node *p;
+ unsigned int bucket;
+
+ bucket = candidate->key_hash & (ARRAY_SIZE(fscache_cookie_hash) - 1);
+ h = &fscache_cookie_hash[bucket];
+
+ hlist_bl_lock(h);
+ hlist_bl_for_each_entry(cursor, p, h, hash_link) {
+ if (fscache_cookie_same(candidate, cursor)) {
+ if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cursor->flags))
+ goto collision;
+ wait_for = fscache_get_cookie(cursor,
+ fscache_cookie_get_hash_collision);
+ break;
+ }
+ }
+
+ fscache_get_volume(candidate->volume, fscache_volume_get_cookie);
+ atomic_inc(&candidate->volume->n_cookies);
+ hlist_bl_add_head(&candidate->hash_link, h);
+ set_bit(FSCACHE_COOKIE_IS_HASHED, &candidate->flags);
+ hlist_bl_unlock(h);
+
+ if (wait_for) {
+ fscache_wait_on_collision(candidate, wait_for);
+ fscache_put_cookie(wait_for, fscache_cookie_put_hash_collision);
+ }
+ return true;
+
+collision:
+ trace_fscache_cookie(cursor->debug_id, refcount_read(&cursor->ref),
+ fscache_cookie_collision);
+ pr_err("Duplicate cookie detected\n");
+ fscache_print_cookie(cursor, 'O');
+ fscache_print_cookie(candidate, 'N');
+ hlist_bl_unlock(h);
+ return false;
+}
+
+/*
+ * Request a cookie to represent a data storage object within a volume.
+ *
+ * We never let on to the netfs about errors. We may set a negative cookie
+ * pointer, but that's okay
+ */
+struct fscache_cookie *__fscache_acquire_cookie(
+ struct fscache_volume *volume,
+ u8 advice,
+ const void *index_key, size_t index_key_len,
+ const void *aux_data, size_t aux_data_len,
+ loff_t object_size)
+{
+ struct fscache_cookie *cookie;
+
+ _enter("V=%x", volume->debug_id);
+
+ if (!index_key || !index_key_len || index_key_len > 255 || aux_data_len > 255)
+ return NULL;
+ if (!aux_data || !aux_data_len) {
+ aux_data = NULL;
+ aux_data_len = 0;
+ }
+
+ fscache_stat(&fscache_n_acquires);
+
+ cookie = fscache_alloc_cookie(volume, advice,
+ index_key, index_key_len,
+ aux_data, aux_data_len,
+ object_size);
+ if (!cookie) {
+ fscache_stat(&fscache_n_acquires_oom);
+ return NULL;
+ }
+
+ if (!fscache_hash_cookie(cookie)) {
+ fscache_see_cookie(cookie, fscache_cookie_discard);
+ fscache_free_cookie(cookie);
+ return NULL;
+ }
+
+ trace_fscache_acquire(cookie);
+ fscache_stat(&fscache_n_acquires_ok);
+ _leave(" = c=%08x", cookie->debug_id);
+ return cookie;
+}
+EXPORT_SYMBOL(__fscache_acquire_cookie);
+
+/*
+ * Remove a cookie from the hash table.
+ */
+static void fscache_unhash_cookie(struct fscache_cookie *cookie)
+{
+ struct hlist_bl_head *h;
+ unsigned int bucket;
+
+ bucket = cookie->key_hash & (ARRAY_SIZE(fscache_cookie_hash) - 1);
+ h = &fscache_cookie_hash[bucket];
+
+ hlist_bl_lock(h);
+ hlist_bl_del(&cookie->hash_link);
+ clear_bit(FSCACHE_COOKIE_IS_HASHED, &cookie->flags);
+ hlist_bl_unlock(h);
+}
+
+/*
+ * Finalise a cookie after all its resources have been disposed of.
+ */
+static void fscache_drop_cookie(struct fscache_cookie *cookie)
+{
+ spin_lock(&cookie->lock);
+ __fscache_set_cookie_state(cookie, FSCACHE_COOKIE_STATE_DROPPED);
+ spin_unlock(&cookie->lock);
+ wake_up_cookie_state(cookie);
+
+ fscache_unhash_cookie(cookie);
+ fscache_stat(&fscache_n_relinquishes_dropped);
+}
+
+/*
+ * Allow the netfs to release a cookie back to the cache.
+ * - the object will be marked as recyclable on disk if retire is true
+ */
+void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
+{
+ fscache_stat(&fscache_n_relinquishes);
+ if (retire)
+ fscache_stat(&fscache_n_relinquishes_retire);
+
+ _enter("c=%08x{%d},%d",
+ cookie->debug_id, atomic_read(&cookie->n_active), retire);
+
+ if (WARN(test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags),
+ "Cookie c=%x already relinquished\n", cookie->debug_id))
+ return;
+
+ if (retire)
+ set_bit(FSCACHE_COOKIE_RETIRED, &cookie->flags);
+ trace_fscache_relinquish(cookie, retire);
+
+ ASSERTCMP(atomic_read(&cookie->n_active), ==, 0);
+ ASSERTCMP(atomic_read(&cookie->volume->n_cookies), >, 0);
+ atomic_dec(&cookie->volume->n_cookies);
+
+ set_bit(FSCACHE_COOKIE_DO_RELINQUISH, &cookie->flags);
+
+ if (test_bit(FSCACHE_COOKIE_HAS_BEEN_CACHED, &cookie->flags))
+ ; // PLACEHOLDER: Do something here if the cookie was cached
+ else
+ fscache_drop_cookie(cookie);
+ fscache_put_cookie(cookie, fscache_cookie_put_relinquish);
+}
+EXPORT_SYMBOL(__fscache_relinquish_cookie);
+
+/*
+ * Drop a reference to a cookie.
+ */
+void fscache_put_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
+{
+ struct fscache_volume *volume = cookie->volume;
+ unsigned int cookie_debug_id = cookie->debug_id;
+ bool zero;
+ int ref;
+
+ zero = __refcount_dec_and_test(&cookie->ref, &ref);
+ trace_fscache_cookie(cookie_debug_id, ref - 1, where);
+ if (zero) {
+ fscache_free_cookie(cookie);
+ fscache_put_volume(volume, fscache_volume_put_cookie);
+ }
+}
+EXPORT_SYMBOL(fscache_put_cookie);
+
+/*
+ * Get a reference to a cookie.
+ */
+struct fscache_cookie *fscache_get_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
+{
+ int ref;
+
+ __refcount_inc(&cookie->ref, &ref);
+ trace_fscache_cookie(cookie->debug_id, ref + 1, where);
+ return cookie;
+}
+EXPORT_SYMBOL(fscache_get_cookie);
+
+/*
+ * Generate a list of extant cookies in /proc/fs/fscache/cookies
+ */
+static int fscache_cookies_seq_show(struct seq_file *m, void *v)
+{
+ struct fscache_cookie *cookie;
+ unsigned int keylen = 0, auxlen = 0;
+ u8 *p;
+
+ if (v == &fscache_cookies) {
+ seq_puts(m,
+ "COOKIE VOLUME REF ACT ACC S FL DEF \n"
+ "======== ======== === === === = == ================\n"
+ );
+ return 0;
+ }
+
+ cookie = list_entry(v, struct fscache_cookie, proc_link);
+
+ seq_printf(m,
+ "%08x %08x %3d %3d %3d %c %02lx",
+ cookie->debug_id,
+ cookie->volume->debug_id,
+ refcount_read(&cookie->ref),
+ atomic_read(&cookie->n_active),
+ atomic_read(&cookie->n_accesses),
+ fscache_cookie_states[cookie->state],
+ cookie->flags);
+
+ keylen = cookie->key_len;
+ auxlen = cookie->aux_len;
+
+ if (keylen > 0 || auxlen > 0) {
+ seq_puts(m, " ");
+ p = keylen <= sizeof(cookie->inline_key) ?
+ cookie->inline_key : cookie->key;
+ for (; keylen > 0; keylen--)
+ seq_printf(m, "%02x", *p++);
+ if (auxlen > 0) {
+ seq_puts(m, ", ");
+ p = auxlen <= sizeof(cookie->inline_aux) ?
+ cookie->inline_aux : cookie->aux;
+ for (; auxlen > 0; auxlen--)
+ seq_printf(m, "%02x", *p++);
+ }
+ }
+
+ seq_puts(m, "\n");
+ return 0;
+}
+
+static void *fscache_cookies_seq_start(struct seq_file *m, loff_t *_pos)
+ __acquires(fscache_cookies_lock)
+{
+ read_lock(&fscache_cookies_lock);
+ return seq_list_start_head(&fscache_cookies, *_pos);
+}
+
+static void *fscache_cookies_seq_next(struct seq_file *m, void *v, loff_t *_pos)
+{
+ return seq_list_next(v, &fscache_cookies, _pos);
+}
+
+static void fscache_cookies_seq_stop(struct seq_file *m, void *v)
+ __releases(rcu)
+{
+ read_unlock(&fscache_cookies_lock);
+}
+
+
+const struct seq_operations fscache_cookies_seq_ops = {
+ .start = fscache_cookies_seq_start,
+ .next = fscache_cookies_seq_next,
+ .stop = fscache_cookies_seq_stop,
+ .show = fscache_cookies_seq_show,
+};
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 07dc9cbc2280..71c897757d44 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -51,6 +51,20 @@ static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
}
/*
+ * cookie.c
+ */
+extern struct kmem_cache *fscache_cookie_jar;
+extern const struct seq_operations fscache_cookies_seq_ops;
+
+extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
+static inline void fscache_see_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
+{
+ trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
+ where);
+}
+
+/*
* main.c
*/
extern unsigned fscache_debug;
@@ -75,6 +89,15 @@ extern void fscache_proc_cleanup(void);
extern atomic_t fscache_n_volumes;
extern atomic_t fscache_n_volumes_collision;
extern atomic_t fscache_n_volumes_nomem;
+extern atomic_t fscache_n_cookies;
+
+extern atomic_t fscache_n_acquires;
+extern atomic_t fscache_n_acquires_ok;
+extern atomic_t fscache_n_acquires_oom;
+
+extern atomic_t fscache_n_relinquishes;
+extern atomic_t fscache_n_relinquishes_retire;
+extern atomic_t fscache_n_relinquishes_dropped;
static inline void fscache_stat(atomic_t *stat)
{
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 687b34903d5b..ae493e9ca1c9 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -79,9 +79,20 @@ static int __init fscache_init(void)
if (ret < 0)
goto error_proc;
+ fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
+ sizeof(struct fscache_cookie),
+ 0, 0, NULL);
+ if (!fscache_cookie_jar) {
+ pr_notice("Failed to allocate a cookie jar\n");
+ ret = -ENOMEM;
+ goto error_cookie_jar;
+ }
+
pr_notice("Loaded\n");
return 0;
+error_cookie_jar:
+ fscache_proc_cleanup();
error_proc:
destroy_workqueue(fscache_wq);
error_wq:
@@ -97,6 +108,7 @@ static void __exit fscache_exit(void)
{
_enter("");
+ kmem_cache_destroy(fscache_cookie_jar);
fscache_proc_cleanup();
destroy_workqueue(fscache_wq);
pr_notice("Unloaded\n");
diff --git a/fs/fscache/proc.c b/fs/fscache/proc.c
index bc6ecbdd065d..dc3b0e9c8cce 100644
--- a/fs/fscache/proc.c
+++ b/fs/fscache/proc.c
@@ -27,6 +27,10 @@ int __init fscache_proc_init(void)
&fscache_volumes_seq_ops))
goto error;
+ if (!proc_create_seq("fs/fscache/cookies", S_IFREG | 0444, NULL,
+ &fscache_cookies_seq_ops))
+ goto error;
+
#ifdef CONFIG_FSCACHE_STATS
if (!proc_create_single("fs/fscache/stats", S_IFREG | 0444, NULL,
fscache_stats_show))
diff --git a/fs/fscache/stats.c b/fs/fscache/stats.c
index b811a4d03585..252e883ae148 100644
--- a/fs/fscache/stats.c
+++ b/fs/fscache/stats.c
@@ -16,6 +16,18 @@
atomic_t fscache_n_volumes;
atomic_t fscache_n_volumes_collision;
atomic_t fscache_n_volumes_nomem;
+atomic_t fscache_n_cookies;
+
+atomic_t fscache_n_acquires;
+atomic_t fscache_n_acquires_ok;
+atomic_t fscache_n_acquires_oom;
+
+atomic_t fscache_n_updates;
+EXPORT_SYMBOL(fscache_n_updates);
+
+atomic_t fscache_n_relinquishes;
+atomic_t fscache_n_relinquishes_retire;
+atomic_t fscache_n_relinquishes_dropped;
/*
* display the general statistics
@@ -23,12 +35,26 @@ atomic_t fscache_n_volumes_nomem;
int fscache_stats_show(struct seq_file *m, void *v)
{
seq_puts(m, "FS-Cache statistics\n");
- seq_printf(m, "Cookies: v=%d vcol=%u voom=%u\n",
+ seq_printf(m, "Cookies: n=%d v=%d vcol=%u voom=%u\n",
+ atomic_read(&fscache_n_cookies),
atomic_read(&fscache_n_volumes),
atomic_read(&fscache_n_volumes_collision),
atomic_read(&fscache_n_volumes_nomem)
);
+ seq_printf(m, "Acquire: n=%u ok=%u oom=%u\n",
+ atomic_read(&fscache_n_acquires),
+ atomic_read(&fscache_n_acquires_ok),
+ atomic_read(&fscache_n_acquires_oom));
+
+ seq_printf(m, "Updates: n=%u\n",
+ atomic_read(&fscache_n_updates));
+
+ seq_printf(m, "Relinqs: n=%u rtr=%u drop=%u\n",
+ atomic_read(&fscache_n_relinquishes),
+ atomic_read(&fscache_n_relinquishes_retire),
+ atomic_read(&fscache_n_relinquishes_dropped));
+
netfs_stats_show(m);
return 0;
}
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 18cd5c9877bb..c4355b888c91 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -17,6 +17,7 @@
#include <linux/fscache.h>
enum fscache_cache_trace;
+enum fscache_cookie_trace;
enum fscache_access_trace;
enum fscache_cache_state {
@@ -52,4 +53,25 @@ extern struct rw_semaphore fscache_addremove_sem;
extern struct fscache_cache *fscache_acquire_cache(const char *name);
extern void fscache_relinquish_cache(struct fscache_cache *cache);
+extern struct fscache_cookie *fscache_get_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where);
+extern void fscache_put_cookie(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where);
+extern void fscache_set_cookie_state(struct fscache_cookie *cookie,
+ enum fscache_cookie_state state);
+
+/**
+ * fscache_get_key - Get a pointer to the cookie key
+ * @cookie: The cookie to query
+ *
+ * Return a pointer to the where a cookie's key is stored.
+ */
+static inline void *fscache_get_key(struct fscache_cookie *cookie)
+{
+ if (cookie->key_len <= sizeof(cookie->inline_key))
+ return cookie->inline_key;
+ else
+ return cookie->key;
+}
+
#endif /* _LINUX_FSCACHE_CACHE_H */
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 131a741a6652..4450d17c11e8 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -31,6 +31,27 @@
#define fscache_cookie_enabled(cookie) (0)
#endif
+struct fscache_cookie;
+
+#define FSCACHE_ADV_SINGLE_CHUNK 0x01 /* The object is a single chunk of data */
+#define FSCACHE_ADV_WRITE_CACHE 0x00 /* Do cache if written to locally */
+#define FSCACHE_ADV_WRITE_NOCACHE 0x02 /* Don't cache if written to locally */
+
+/*
+ * Data object state.
+ */
+enum fscache_cookie_state {
+ FSCACHE_COOKIE_STATE_QUIESCENT, /* The cookie is uncached */
+ FSCACHE_COOKIE_STATE_LOOKING_UP, /* The cache object is being looked up */
+ FSCACHE_COOKIE_STATE_CREATING, /* The cache object is being created */
+ FSCACHE_COOKIE_STATE_ACTIVE, /* The cache is active, readable and writable */
+ FSCACHE_COOKIE_STATE_FAILED, /* The cache failed, withdraw to clear */
+ FSCACHE_COOKIE_STATE_WITHDRAWING, /* The cookie is being withdrawn */
+ FSCACHE_COOKIE_STATE_RELINQUISHING, /* The cookie is being relinquished */
+ FSCACHE_COOKIE_STATE_DROPPED, /* The cookie has been dropped */
+#define FSCACHE_COOKIE_STATE__NR (FSCACHE_COOKIE_STATE_DROPPED + 1)
+} __attribute__((mode(byte)));
+
/*
* Volume representation cookie.
*/
@@ -56,6 +77,60 @@ struct fscache_volume {
};
/*
+ * Data file representation cookie.
+ * - a file will only appear in one cache
+ * - a request to cache a file may or may not be honoured, subject to
+ * constraints such as disk space
+ * - indices are created on disk just-in-time
+ */
+struct fscache_cookie {
+ refcount_t ref;
+ atomic_t n_active; /* number of active users of cookie */
+ atomic_t n_accesses; /* Number of cache accesses in progress */
+ unsigned int debug_id;
+ unsigned int inval_counter; /* Number of invalidations made */
+ spinlock_t lock;
+ struct fscache_volume *volume; /* Parent volume of this file. */
+ void *cache_priv; /* Cache-side representation */
+ struct hlist_bl_node hash_link; /* Link in hash table */
+ struct list_head proc_link; /* Link in proc list */
+ struct list_head commit_link; /* Link in commit queue */
+ struct work_struct work; /* Commit/relinq/withdraw work */
+ loff_t object_size; /* Size of the netfs object */
+ unsigned long unused_at; /* Time at which unused (jiffies) */
+ unsigned long flags;
+#define FSCACHE_COOKIE_RELINQUISHED 0 /* T if cookie has been relinquished */
+#define FSCACHE_COOKIE_RETIRED 1 /* T if this cookie has retired on relinq */
+#define FSCACHE_COOKIE_IS_CACHING 2 /* T if this cookie is cached */
+#define FSCACHE_COOKIE_NO_DATA_TO_READ 3 /* T if this cookie has nothing to read */
+#define FSCACHE_COOKIE_NEEDS_UPDATE 4 /* T if attrs have been updated */
+#define FSCACHE_COOKIE_HAS_BEEN_CACHED 5 /* T if cookie needs withdraw-on-relinq */
+#define FSCACHE_COOKIE_DISABLED 6 /* T if cookie has been disabled */
+#define FSCACHE_COOKIE_LOCAL_WRITE 7 /* T if cookie has been modified locally */
+#define FSCACHE_COOKIE_NO_ACCESS_WAKE 8 /* T if no wake when n_accesses goes 0 */
+#define FSCACHE_COOKIE_DO_RELINQUISH 9 /* T if this cookie needs relinquishment */
+#define FSCACHE_COOKIE_DO_WITHDRAW 10 /* T if this cookie needs withdrawing */
+#define FSCACHE_COOKIE_DO_LRU_DISCARD 11 /* T if this cookie needs LRU discard */
+#define FSCACHE_COOKIE_DO_PREP_TO_WRITE 12 /* T if cookie needs write preparation */
+#define FSCACHE_COOKIE_HAVE_DATA 13 /* T if this cookie has data stored */
+#define FSCACHE_COOKIE_IS_HASHED 14 /* T if this cookie is hashed */
+
+ enum fscache_cookie_state state;
+ u8 advice; /* FSCACHE_ADV_* */
+ u8 key_len; /* Length of index key */
+ u8 aux_len; /* Length of auxiliary data */
+ u32 key_hash; /* Hash of volume, key, len */
+ union {
+ void *key; /* Index key */
+ u8 inline_key[16]; /* - If the key is short enough */
+ };
+ union {
+ void *aux; /* Auxiliary data */
+ u8 inline_aux[8]; /* - If the aux data is short enough */
+ };
+};
+
+/*
* slow-path functions for when there is actually caching available, and the
* netfs does actually have a valid token
* - these are not to be called directly
@@ -66,6 +141,14 @@ extern struct fscache_volume *__fscache_acquire_volume(const char *, const char
const void *, size_t);
extern void __fscache_relinquish_volume(struct fscache_volume *, const void *, bool);
+extern struct fscache_cookie *__fscache_acquire_cookie(
+ struct fscache_volume *,
+ u8,
+ const void *, size_t,
+ const void *, size_t,
+ loff_t);
+extern void __fscache_relinquish_cookie(struct fscache_cookie *, bool);
+
/**
* fscache_acquire_volume - Register a volume as desiring caching services
* @volume_key: An identification string for the volume
@@ -113,4 +196,55 @@ void fscache_relinquish_volume(struct fscache_volume *volume,
__fscache_relinquish_volume(volume, coherency_data, invalidate);
}
+/**
+ * fscache_acquire_cookie - Acquire a cookie to represent a cache object
+ * @volume: The volume in which to locate/create this cookie
+ * @advice: Advice flags (FSCACHE_COOKIE_ADV_*)
+ * @index_key: The index key for this cookie
+ * @index_key_len: Size of the index key
+ * @aux_data: The auxiliary data for the cookie (may be NULL)
+ * @aux_data_len: Size of the auxiliary data buffer
+ * @object_size: The initial size of object
+ *
+ * Acquire a cookie to represent a data file within the given cache volume.
+ *
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
+ * description.
+ */
+static inline
+struct fscache_cookie *fscache_acquire_cookie(struct fscache_volume *volume,
+ u8 advice,
+ const void *index_key,
+ size_t index_key_len,
+ const void *aux_data,
+ size_t aux_data_len,
+ loff_t object_size)
+{
+ if (!fscache_volume_valid(volume))
+ return NULL;
+ return __fscache_acquire_cookie(volume, advice,
+ index_key, index_key_len,
+ aux_data, aux_data_len,
+ object_size);
+}
+
+/**
+ * fscache_relinquish_cookie - Return the cookie to the cache, maybe discarding
+ * it
+ * @cookie: The cookie being returned
+ * @retire: True if the cache object the cookie represents is to be discarded
+ *
+ * This function returns a cookie to the cache, forcibly discarding the
+ * associated cache object if retire is set to true.
+ *
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
+ * description.
+ */
+static inline
+void fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
+{
+ if (fscache_cookie_valid(cookie))
+ __fscache_relinquish_cookie(cookie, retire);
+}
+
#endif /* _LINUX_FSCACHE_H */
diff --git a/include/trace/events/fscache.h b/include/trace/events/fscache.h
index eeb3e7d88e20..9286e1c4b2ac 100644
--- a/include/trace/events/fscache.h
+++ b/include/trace/events/fscache.h
@@ -45,6 +45,23 @@ enum fscache_volume_trace {
fscache_volume_see_hash_wake,
};
+enum fscache_cookie_trace {
+ fscache_cookie_collision,
+ fscache_cookie_discard,
+ fscache_cookie_get_end_access,
+ fscache_cookie_get_hash_collision,
+ fscache_cookie_new_acquire,
+ fscache_cookie_put_hash_collision,
+ fscache_cookie_put_over_queued,
+ fscache_cookie_put_relinquish,
+ fscache_cookie_put_withdrawn,
+ fscache_cookie_put_work,
+ fscache_cookie_see_active,
+ fscache_cookie_see_relinquish,
+ fscache_cookie_see_withdraw,
+ fscache_cookie_see_work,
+};
+
#endif
/*
@@ -74,6 +91,22 @@ enum fscache_volume_trace {
EM(fscache_volume_see_create_work, "SEE creat") \
E_(fscache_volume_see_hash_wake, "SEE hwake")
+#define fscache_cookie_traces \
+ EM(fscache_cookie_collision, "*COLLIDE*") \
+ EM(fscache_cookie_discard, "DISCARD ") \
+ EM(fscache_cookie_get_hash_collision, "GET hcoll") \
+ EM(fscache_cookie_get_end_access, "GQ endac") \
+ EM(fscache_cookie_new_acquire, "NEW acq ") \
+ EM(fscache_cookie_put_hash_collision, "PUT hcoll") \
+ EM(fscache_cookie_put_over_queued, "PQ overq") \
+ EM(fscache_cookie_put_relinquish, "PUT relnq") \
+ EM(fscache_cookie_put_withdrawn, "PUT wthdn") \
+ EM(fscache_cookie_put_work, "PQ work ") \
+ EM(fscache_cookie_see_active, "- activ") \
+ EM(fscache_cookie_see_relinquish, "- x-rlq") \
+ EM(fscache_cookie_see_withdraw, "- x-wth") \
+ E_(fscache_cookie_see_work, "- work ")
+
/*
* Export enum symbols via userspace.
*/
@@ -84,6 +117,7 @@ enum fscache_volume_trace {
fscache_cache_traces;
fscache_volume_traces;
+fscache_cookie_traces;
/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -145,6 +179,83 @@ TRACE_EVENT(fscache_volume,
__entry->usage)
);
+TRACE_EVENT(fscache_cookie,
+ TP_PROTO(unsigned int cookie_debug_id,
+ int ref,
+ enum fscache_cookie_trace where),
+
+ TP_ARGS(cookie_debug_id, ref, where),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, cookie )
+ __field(int, ref )
+ __field(enum fscache_cookie_trace, where )
+ ),
+
+ TP_fast_assign(
+ __entry->cookie = cookie_debug_id;
+ __entry->ref = ref;
+ __entry->where = where;
+ ),
+
+ TP_printk("c=%08x %s r=%d",
+ __entry->cookie,
+ __print_symbolic(__entry->where, fscache_cookie_traces),
+ __entry->ref)
+ );
+
+TRACE_EVENT(fscache_acquire,
+ TP_PROTO(struct fscache_cookie *cookie),
+
+ TP_ARGS(cookie),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, cookie )
+ __field(unsigned int, volume )
+ __field(int, v_ref )
+ __field(int, v_n_cookies )
+ ),
+
+ TP_fast_assign(
+ __entry->cookie = cookie->debug_id;
+ __entry->volume = cookie->volume->debug_id;
+ __entry->v_ref = refcount_read(&cookie->volume->ref);
+ __entry->v_n_cookies = atomic_read(&cookie->volume->n_cookies);
+ ),
+
+ TP_printk("c=%08x V=%08x vr=%d vc=%d",
+ __entry->cookie,
+ __entry->volume, __entry->v_ref, __entry->v_n_cookies)
+ );
+
+TRACE_EVENT(fscache_relinquish,
+ TP_PROTO(struct fscache_cookie *cookie, bool retire),
+
+ TP_ARGS(cookie, retire),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, cookie )
+ __field(unsigned int, volume )
+ __field(int, ref )
+ __field(int, n_active )
+ __field(u8, flags )
+ __field(bool, retire )
+ ),
+
+ TP_fast_assign(
+ __entry->cookie = cookie->debug_id;
+ __entry->volume = cookie->volume->debug_id;
+ __entry->ref = refcount_read(&cookie->ref);
+ __entry->n_active = atomic_read(&cookie->n_active);
+ __entry->flags = cookie->flags;
+ __entry->retire = retire;
+ ),
+
+ TP_printk("c=%08x V=%08x r=%d U=%d f=%02x rt=%u",
+ __entry->cookie, __entry->volume, __entry->ref,
+ __entry->n_active, __entry->flags, __entry->retire)
+ );
+
#endif /* _TRACE_FSCACHE_H */
/* This part must be outside protection */
generated by cgit (git 2.34.1) at 2024-05-23 09:45:50 +0000