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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | /* General filesystem local caching manager * * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #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> #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 __user *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 /* * 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, fscache_cookie_init_once); 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); /* * wait_on_atomic_t() sleep function for uninterruptible waiting */ int fscache_wait_atomic_t(atomic_t *p) { schedule(); return 0; } |