diff options
Diffstat (limited to 'fs/fscache/main.c')
-rw-r--r-- | fs/fscache/main.c | 230 |
1 files changed, 0 insertions, 230 deletions
diff --git a/fs/fscache/main.c b/fs/fscache/main.c deleted file mode 100644 index 4207f98e405f..000000000000 --- a/fs/fscache/main.c +++ /dev/null @@ -1,230 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* General filesystem local caching manager - * - * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - */ - -#define FSCACHE_DEBUG_LEVEL CACHE -#include <linux/module.h> -#include <linux/init.h> -#include <linux/sched.h> -#include <linux/completion.h> -#include <linux/slab.h> -#include <linux/seq_file.h> -#define CREATE_TRACE_POINTS -#include "internal.h" - -MODULE_DESCRIPTION("FS Cache Manager"); -MODULE_AUTHOR("Red Hat, Inc."); -MODULE_LICENSE("GPL"); - -unsigned fscache_defer_lookup = 1; -module_param_named(defer_lookup, fscache_defer_lookup, uint, - S_IWUSR | S_IRUGO); -MODULE_PARM_DESC(fscache_defer_lookup, - "Defer cookie lookup to background thread"); - -unsigned fscache_defer_create = 1; -module_param_named(defer_create, fscache_defer_create, uint, - S_IWUSR | S_IRUGO); -MODULE_PARM_DESC(fscache_defer_create, - "Defer cookie creation to background thread"); - -unsigned fscache_debug; -module_param_named(debug, fscache_debug, uint, - S_IWUSR | S_IRUGO); -MODULE_PARM_DESC(fscache_debug, - "FS-Cache debugging mask"); - -struct kobject *fscache_root; -struct workqueue_struct *fscache_object_wq; -struct workqueue_struct *fscache_op_wq; - -DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait); - -/* these values serve as lower bounds, will be adjusted in fscache_init() */ -static unsigned fscache_object_max_active = 4; -static unsigned fscache_op_max_active = 2; - -#ifdef CONFIG_SYSCTL -static struct ctl_table_header *fscache_sysctl_header; - -static int fscache_max_active_sysctl(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) -{ - struct workqueue_struct **wqp = table->extra1; - unsigned int *datap = table->data; - int ret; - - ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret == 0) - workqueue_set_max_active(*wqp, *datap); - return ret; -} - -static struct ctl_table fscache_sysctls[] = { - { - .procname = "object_max_active", - .data = &fscache_object_max_active, - .maxlen = sizeof(unsigned), - .mode = 0644, - .proc_handler = fscache_max_active_sysctl, - .extra1 = &fscache_object_wq, - }, - { - .procname = "operation_max_active", - .data = &fscache_op_max_active, - .maxlen = sizeof(unsigned), - .mode = 0644, - .proc_handler = fscache_max_active_sysctl, - .extra1 = &fscache_op_wq, - }, - {} -}; - -static struct ctl_table fscache_sysctls_root[] = { - { - .procname = "fscache", - .mode = 0555, - .child = fscache_sysctls, - }, - {} -}; -#endif - -/* - * Mixing scores (in bits) for (7,20): - * Input delta: 1-bit 2-bit - * 1 round: 330.3 9201.6 - * 2 rounds: 1246.4 25475.4 - * 3 rounds: 1907.1 31295.1 - * 4 rounds: 2042.3 31718.6 - * Perfect: 2048 31744 - * (32*64) (32*31/2 * 64) - */ -#define HASH_MIX(x, y, a) \ - ( x ^= (a), \ - y ^= x, x = rol32(x, 7),\ - x += y, y = rol32(y,20),\ - y *= 9 ) - -static inline unsigned int fold_hash(unsigned long x, unsigned long y) -{ - /* Use arch-optimized multiply if one exists */ - return __hash_32(y ^ __hash_32(x)); -} - -/* - * Generate a hash. This is derived from full_name_hash(), but we want to be - * sure it is arch independent and that it doesn't change as bits of the - * computed hash value might appear on disk. The caller also guarantees that - * the hashed data will be a series of aligned 32-bit words. - */ -unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n) -{ - unsigned int a, x = 0, y = salt; - - for (; n; n--) { - a = *data++; - HASH_MIX(x, y, a); - } - return fold_hash(x, y); -} - -/* - * initialise the fs caching module - */ -static int __init fscache_init(void) -{ - unsigned int nr_cpus = num_possible_cpus(); - unsigned int cpu; - int ret; - - fscache_object_max_active = - clamp_val(nr_cpus, - fscache_object_max_active, WQ_UNBOUND_MAX_ACTIVE); - - ret = -ENOMEM; - fscache_object_wq = alloc_workqueue("fscache_object", WQ_UNBOUND, - fscache_object_max_active); - if (!fscache_object_wq) - goto error_object_wq; - - fscache_op_max_active = - clamp_val(fscache_object_max_active / 2, - fscache_op_max_active, WQ_UNBOUND_MAX_ACTIVE); - - ret = -ENOMEM; - fscache_op_wq = alloc_workqueue("fscache_operation", WQ_UNBOUND, - fscache_op_max_active); - if (!fscache_op_wq) - goto error_op_wq; - - for_each_possible_cpu(cpu) - init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu)); - - ret = fscache_proc_init(); - if (ret < 0) - goto error_proc; - -#ifdef CONFIG_SYSCTL - ret = -ENOMEM; - fscache_sysctl_header = register_sysctl_table(fscache_sysctls_root); - if (!fscache_sysctl_header) - goto error_sysctl; -#endif - - 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; - } - - fscache_root = kobject_create_and_add("fscache", kernel_kobj); - if (!fscache_root) - goto error_kobj; - - pr_notice("Loaded\n"); - return 0; - -error_kobj: - kmem_cache_destroy(fscache_cookie_jar); -error_cookie_jar: -#ifdef CONFIG_SYSCTL - unregister_sysctl_table(fscache_sysctl_header); -error_sysctl: -#endif - fscache_proc_cleanup(); -error_proc: - destroy_workqueue(fscache_op_wq); -error_op_wq: - destroy_workqueue(fscache_object_wq); -error_object_wq: - return ret; -} - -fs_initcall(fscache_init); - -/* - * clean up on module removal - */ -static void __exit fscache_exit(void) -{ - _enter(""); - - kobject_put(fscache_root); - kmem_cache_destroy(fscache_cookie_jar); -#ifdef CONFIG_SYSCTL - unregister_sysctl_table(fscache_sysctl_header); -#endif - fscache_proc_cleanup(); - destroy_workqueue(fscache_op_wq); - destroy_workqueue(fscache_object_wq); - pr_notice("Unloaded\n"); -} - -module_exit(fscache_exit); |