1 /* General filesystem local caching manager 2 * 3 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #define FSCACHE_DEBUG_LEVEL CACHE 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/sched.h> 16 #include <linux/completion.h> 17 #include <linux/slab.h> 18 #include "internal.h" 19 20 MODULE_DESCRIPTION("FS Cache Manager"); 21 MODULE_AUTHOR("Red Hat, Inc."); 22 MODULE_LICENSE("GPL"); 23 24 unsigned fscache_defer_lookup = 1; 25 module_param_named(defer_lookup, fscache_defer_lookup, uint, 26 S_IWUSR | S_IRUGO); 27 MODULE_PARM_DESC(fscache_defer_lookup, 28 "Defer cookie lookup to background thread"); 29 30 unsigned fscache_defer_create = 1; 31 module_param_named(defer_create, fscache_defer_create, uint, 32 S_IWUSR | S_IRUGO); 33 MODULE_PARM_DESC(fscache_defer_create, 34 "Defer cookie creation to background thread"); 35 36 unsigned fscache_debug; 37 module_param_named(debug, fscache_debug, uint, 38 S_IWUSR | S_IRUGO); 39 MODULE_PARM_DESC(fscache_debug, 40 "FS-Cache debugging mask"); 41 42 struct kobject *fscache_root; 43 44 /* 45 * initialise the fs caching module 46 */ 47 static int __init fscache_init(void) 48 { 49 int ret; 50 51 ret = slow_work_register_user(THIS_MODULE); 52 if (ret < 0) 53 goto error_slow_work; 54 55 ret = fscache_proc_init(); 56 if (ret < 0) 57 goto error_proc; 58 59 fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar", 60 sizeof(struct fscache_cookie), 61 0, 62 0, 63 fscache_cookie_init_once); 64 if (!fscache_cookie_jar) { 65 printk(KERN_NOTICE 66 "FS-Cache: Failed to allocate a cookie jar\n"); 67 ret = -ENOMEM; 68 goto error_cookie_jar; 69 } 70 71 fscache_root = kobject_create_and_add("fscache", kernel_kobj); 72 if (!fscache_root) 73 goto error_kobj; 74 75 printk(KERN_NOTICE "FS-Cache: Loaded\n"); 76 return 0; 77 78 error_kobj: 79 kmem_cache_destroy(fscache_cookie_jar); 80 error_cookie_jar: 81 fscache_proc_cleanup(); 82 error_proc: 83 slow_work_unregister_user(THIS_MODULE); 84 error_slow_work: 85 return ret; 86 } 87 88 fs_initcall(fscache_init); 89 90 /* 91 * clean up on module removal 92 */ 93 static void __exit fscache_exit(void) 94 { 95 _enter(""); 96 97 kobject_put(fscache_root); 98 kmem_cache_destroy(fscache_cookie_jar); 99 fscache_proc_cleanup(); 100 slow_work_unregister_user(THIS_MODULE); 101 printk(KERN_NOTICE "FS-Cache: Unloaded\n"); 102 } 103 104 module_exit(fscache_exit); 105 106 /* 107 * wait_on_bit() sleep function for uninterruptible waiting 108 */ 109 int fscache_wait_bit(void *flags) 110 { 111 schedule(); 112 return 0; 113 } 114 EXPORT_SYMBOL(fscache_wait_bit); 115 116 /* 117 * wait_on_bit() sleep function for interruptible waiting 118 */ 119 int fscache_wait_bit_interruptible(void *flags) 120 { 121 schedule(); 122 return signal_pending(current); 123 } 124 EXPORT_SYMBOL(fscache_wait_bit_interruptible); 125