Implement allocate, get, see and put functions for the cachefiles_object struct. The members of the struct we're going to need are also added. Additionally, implement a lifecycle tracepoint. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: linux-cachefs@xxxxxxxxxx Link: https://lore.kernel.org/r/163819639457.215744.4600093239395728232.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1 --- fs/cachefiles/interface.c | 86 +++++++++++++++++++++++++++++++++++++ fs/cachefiles/internal.h | 35 ++++++++++++++- fs/cachefiles/main.c | 16 +++++++ include/trace/events/cachefiles.h | 58 +++++++++++++++++++++++++ include/trace/events/fscache.h | 4 ++ 5 files changed, 197 insertions(+), 2 deletions(-) diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index 1793e46bd3e7..68bb7b6c4945 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -13,6 +13,92 @@ #include <trace/events/fscache.h> #include "internal.h" +static atomic_t cachefiles_object_debug_id; + +/* + * Allocate a cache object record. + */ +static +struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie) +{ + struct fscache_volume *vcookie = cookie->volume; + struct cachefiles_volume *volume = vcookie->cache_priv; + struct cachefiles_object *object; + + _enter("{%s},%x,", vcookie->key, cookie->debug_id); + + object = kmem_cache_zalloc(cachefiles_object_jar, GFP_KERNEL); + if (!object) + return NULL; + + refcount_set(&object->ref, 1); + + spin_lock_init(&object->lock); + INIT_LIST_HEAD(&object->cache_link); + object->volume = volume; + object->debug_id = atomic_inc_return(&cachefiles_object_debug_id); + object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object); + + fscache_count_object(vcookie->cache); + trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1, + cachefiles_obj_new); + return object; +} + +/* + * Note that an object has been seen. + */ +void cachefiles_see_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) +{ + trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, + refcount_read(&object->ref), why); +} + +/* + * Increment the usage count on an object; + */ +struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) +{ + int r; + + __refcount_inc(&object->ref, &r); + trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, r, why); + return object; +} + +/* + * dispose of a reference to an object + */ +void cachefiles_put_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why) +{ + unsigned int object_debug_id = object->debug_id; + unsigned int cookie_debug_id = object->cookie->debug_id; + struct fscache_cache *cache; + bool done; + int r; + + done = __refcount_dec_and_test(&object->ref, &r); + trace_cachefiles_ref(object_debug_id, cookie_debug_id, r, why); + if (done) { + _debug("- kill object OBJ%x", object_debug_id); + + ASSERTCMP(object->file, ==, NULL); + + kfree(object->d_name); + + cache = object->volume->cache->cache; + fscache_put_cookie(object->cookie, fscache_cookie_put_object); + object->cookie = NULL; + kmem_cache_free(cachefiles_object_jar, object); + fscache_uncount_object(cache); + } + + _leave(""); +} + const struct fscache_cache_ops cachefiles_cache_ops = { .name = "cachefiles", .acquire_volume = cachefiles_acquire_volume, diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 3b1a6d67cf96..ff378171c71d 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -19,6 +19,16 @@ struct cachefiles_cache; struct cachefiles_object; +enum cachefiles_content { + /* These values are saved on disk */ + CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */ + CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */ + CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */ + CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */ + CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */ + nr__cachefiles_content +}; + /* * Cached volume representation. */ @@ -31,10 +41,20 @@ struct cachefiles_volume { }; /* - * Data file records. + * Backing file state. */ struct cachefiles_object { - int debug_id; /* debugging ID */ + struct fscache_cookie *cookie; /* Netfs data storage object cookie */ + struct cachefiles_volume *volume; /* Cache volume that holds this object */ + struct list_head cache_link; /* Link in cache->*_list */ + struct file *file; /* The file representing this object */ + char *d_name; /* Backing file name */ + int debug_id; + spinlock_t lock; + refcount_t ref; + u8 d_name_len; /* Length of filename */ + enum cachefiles_content content_info:8; /* Info about content presence */ + unsigned long flags; }; /* @@ -146,6 +166,17 @@ static inline int cachefiles_inject_remove_error(void) * interface.c */ extern const struct fscache_cache_ops cachefiles_cache_ops; +extern void cachefiles_see_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why); +extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why); +extern void cachefiles_put_object(struct cachefiles_object *object, + enum cachefiles_obj_ref_trace why); + +/* + * main.c + */ +extern struct kmem_cache *cachefiles_object_jar; /* * namei.c diff --git a/fs/cachefiles/main.c b/fs/cachefiles/main.c index 533e3067d80f..3f369c6f816d 100644 --- a/fs/cachefiles/main.c +++ b/fs/cachefiles/main.c @@ -31,6 +31,8 @@ MODULE_DESCRIPTION("Mounted-filesystem based cache"); MODULE_AUTHOR("Red Hat, Inc."); MODULE_LICENSE("GPL"); +struct kmem_cache *cachefiles_object_jar; + static struct miscdevice cachefiles_dev = { .minor = MISC_DYNAMIC_MINOR, .name = "cachefiles", @@ -51,9 +53,22 @@ static int __init cachefiles_init(void) if (ret < 0) goto error_dev; + /* create an object jar */ + ret = -ENOMEM; + cachefiles_object_jar = + kmem_cache_create("cachefiles_object_jar", + sizeof(struct cachefiles_object), + 0, SLAB_HWCACHE_ALIGN, NULL); + if (!cachefiles_object_jar) { + pr_notice("Failed to allocate an object jar\n"); + goto error_object_jar; + } + pr_info("Loaded\n"); return 0; +error_object_jar: + misc_deregister(&cachefiles_dev); error_dev: cachefiles_unregister_error_injection(); error_einj: @@ -70,6 +85,7 @@ static void __exit cachefiles_exit(void) { pr_info("Unloading\n"); + kmem_cache_destroy(cachefiles_object_jar); misc_deregister(&cachefiles_dev); cachefiles_unregister_error_injection(); } diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h index b548dbaf85bb..493afa7fbfec 100644 --- a/include/trace/events/cachefiles.h +++ b/include/trace/events/cachefiles.h @@ -18,6 +18,21 @@ #ifndef __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY #define __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY +enum cachefiles_obj_ref_trace { + cachefiles_obj_get_ioreq, + cachefiles_obj_new, + cachefiles_obj_put_alloc_fail, + cachefiles_obj_put_detach, + cachefiles_obj_put_ioreq, + cachefiles_obj_see_clean_commit, + cachefiles_obj_see_clean_delete, + cachefiles_obj_see_clean_drop_tmp, + cachefiles_obj_see_lookup_cookie, + cachefiles_obj_see_lookup_failed, + cachefiles_obj_see_withdraw_cookie, + cachefiles_obj_see_withdrawal, +}; + enum fscache_why_object_killed { FSCACHE_OBJECT_IS_STALE, FSCACHE_OBJECT_IS_WEIRD, @@ -66,6 +81,20 @@ enum cachefiles_error_trace { EM(FSCACHE_OBJECT_WAS_RETIRED, "was_retired") \ E_(FSCACHE_OBJECT_WAS_CULLED, "was_culled") +#define cachefiles_obj_ref_traces \ + EM(cachefiles_obj_get_ioreq, "GET ioreq") \ + EM(cachefiles_obj_new, "NEW obj") \ + EM(cachefiles_obj_put_alloc_fail, "PUT alloc_fail") \ + EM(cachefiles_obj_put_detach, "PUT detach") \ + EM(cachefiles_obj_put_ioreq, "PUT ioreq") \ + EM(cachefiles_obj_see_clean_commit, "SEE clean_commit") \ + EM(cachefiles_obj_see_clean_delete, "SEE clean_delete") \ + EM(cachefiles_obj_see_clean_drop_tmp, "SEE clean_drop_tmp") \ + EM(cachefiles_obj_see_lookup_cookie, "SEE lookup_cookie") \ + EM(cachefiles_obj_see_lookup_failed, "SEE lookup_failed") \ + EM(cachefiles_obj_see_withdraw_cookie, "SEE withdraw_cookie") \ + E_(cachefiles_obj_see_withdrawal, "SEE withdrawal") + #define cachefiles_trunc_traces \ EM(cachefiles_trunc_dio_adjust, "DIOADJ") \ EM(cachefiles_trunc_expand_tmpfile, "EXPTMP") \ @@ -100,6 +129,7 @@ enum cachefiles_error_trace { #define E_(a, b) TRACE_DEFINE_ENUM(a); cachefiles_obj_kill_traces; +cachefiles_obj_ref_traces; cachefiles_trunc_traces; cachefiles_error_traces; @@ -113,6 +143,34 @@ cachefiles_error_traces; #define E_(a, b) { a, b } +TRACE_EVENT(cachefiles_ref, + TP_PROTO(unsigned int object_debug_id, + unsigned int cookie_debug_id, + int usage, + enum cachefiles_obj_ref_trace why), + + TP_ARGS(object_debug_id, cookie_debug_id, usage, why), + + /* Note that obj may be NULL */ + TP_STRUCT__entry( + __field(unsigned int, obj ) + __field(unsigned int, cookie ) + __field(enum cachefiles_obj_ref_trace, why ) + __field(int, usage ) + ), + + TP_fast_assign( + __entry->obj = object_debug_id; + __entry->cookie = cookie_debug_id; + __entry->usage = usage; + __entry->why = why; + ), + + TP_printk("c=%08x o=%08x u=%d %s", + __entry->cookie, __entry->obj, __entry->usage, + __print_symbolic(__entry->why, cachefiles_obj_ref_traces)) + ); + TRACE_EVENT(cachefiles_lookup, TP_PROTO(struct cachefiles_object *obj, struct dentry *de), diff --git a/include/trace/events/fscache.h b/include/trace/events/fscache.h index 5fa37a8b4ec7..d9d830296ec3 100644 --- a/include/trace/events/fscache.h +++ b/include/trace/events/fscache.h @@ -49,6 +49,7 @@ enum fscache_volume_trace { enum fscache_cookie_trace { fscache_cookie_collision, fscache_cookie_discard, + fscache_cookie_get_attach_object, fscache_cookie_get_end_access, fscache_cookie_get_hash_collision, fscache_cookie_get_inval_work, @@ -57,6 +58,7 @@ enum fscache_cookie_trace { fscache_cookie_new_acquire, fscache_cookie_put_hash_collision, fscache_cookie_put_lru, + fscache_cookie_put_object, fscache_cookie_put_over_queued, fscache_cookie_put_relinquish, fscache_cookie_put_withdrawn, @@ -122,6 +124,7 @@ enum fscache_access_trace { #define fscache_cookie_traces \ EM(fscache_cookie_collision, "*COLLIDE*") \ EM(fscache_cookie_discard, "DISCARD ") \ + EM(fscache_cookie_get_attach_object, "GET attch") \ EM(fscache_cookie_get_hash_collision, "GET hcoll") \ EM(fscache_cookie_get_end_access, "GQ endac") \ EM(fscache_cookie_get_inval_work, "GQ inval") \ @@ -130,6 +133,7 @@ enum fscache_access_trace { EM(fscache_cookie_new_acquire, "NEW acq ") \ EM(fscache_cookie_put_hash_collision, "PUT hcoll") \ EM(fscache_cookie_put_lru, "PUT lru ") \ + EM(fscache_cookie_put_object, "PUT obj ") \ EM(fscache_cookie_put_over_queued, "PQ overq") \ EM(fscache_cookie_put_relinquish, "PUT relnq") \ EM(fscache_cookie_put_withdrawn, "PUT wthdn") \
