1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Miscellaneous bits for the netfs support library. 3 * 4 * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #include <linux/module.h> 9 #include <linux/export.h> 10 #include <linux/mempool.h> 11 #include <linux/proc_fs.h> 12 #include <linux/seq_file.h> 13 #include "internal.h" 14 #define CREATE_TRACE_POINTS 15 #include <trace/events/netfs.h> 16 17 MODULE_DESCRIPTION("Network fs support"); 18 MODULE_AUTHOR("Red Hat, Inc."); 19 MODULE_LICENSE("GPL"); 20 21 EXPORT_TRACEPOINT_SYMBOL(netfs_sreq); 22 23 unsigned netfs_debug; 24 module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); 25 MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); 26 27 static struct kmem_cache *netfs_request_slab; 28 static struct kmem_cache *netfs_subrequest_slab; 29 mempool_t netfs_request_pool; 30 mempool_t netfs_subrequest_pool; 31 32 #ifdef CONFIG_PROC_FS 33 LIST_HEAD(netfs_io_requests); 34 DEFINE_SPINLOCK(netfs_proc_lock); 35 36 static const char *netfs_origins[nr__netfs_io_origin] = { 37 [NETFS_READAHEAD] = "RA", 38 [NETFS_READPAGE] = "RP", 39 [NETFS_READ_FOR_WRITE] = "RW", 40 [NETFS_COPY_TO_CACHE] = "CC", 41 [NETFS_WRITEBACK] = "WB", 42 [NETFS_WRITETHROUGH] = "WT", 43 [NETFS_UNBUFFERED_WRITE] = "UW", 44 [NETFS_DIO_READ] = "DR", 45 [NETFS_DIO_WRITE] = "DW", 46 }; 47 48 /* 49 * Generate a list of I/O requests in /proc/fs/netfs/requests 50 */ 51 static int netfs_requests_seq_show(struct seq_file *m, void *v) 52 { 53 struct netfs_io_request *rreq; 54 55 if (v == &netfs_io_requests) { 56 seq_puts(m, 57 "REQUEST OR REF FL ERR OPS COVERAGE\n" 58 "======== == === == ==== === =========\n" 59 ); 60 return 0; 61 } 62 63 rreq = list_entry(v, struct netfs_io_request, proc_link); 64 seq_printf(m, 65 "%08x %s %3d %2lx %4d %3d @%04llx %llx/%llx", 66 rreq->debug_id, 67 netfs_origins[rreq->origin], 68 refcount_read(&rreq->ref), 69 rreq->flags, 70 rreq->error, 71 atomic_read(&rreq->nr_outstanding), 72 rreq->start, rreq->submitted, rreq->len); 73 seq_putc(m, '\n'); 74 return 0; 75 } 76 77 static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) 78 __acquires(rcu) 79 { 80 rcu_read_lock(); 81 return seq_list_start_head(&netfs_io_requests, *_pos); 82 } 83 84 static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) 85 { 86 return seq_list_next(v, &netfs_io_requests, _pos); 87 } 88 89 static void netfs_requests_seq_stop(struct seq_file *m, void *v) 90 __releases(rcu) 91 { 92 rcu_read_unlock(); 93 } 94 95 static const struct seq_operations netfs_requests_seq_ops = { 96 .start = netfs_requests_seq_start, 97 .next = netfs_requests_seq_next, 98 .stop = netfs_requests_seq_stop, 99 .show = netfs_requests_seq_show, 100 }; 101 #endif /* CONFIG_PROC_FS */ 102 103 static int __init netfs_init(void) 104 { 105 int ret = -ENOMEM; 106 107 netfs_request_slab = kmem_cache_create("netfs_request", 108 sizeof(struct netfs_io_request), 0, 109 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 110 NULL); 111 if (!netfs_request_slab) 112 goto error_req; 113 114 if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0) 115 goto error_reqpool; 116 117 netfs_subrequest_slab = kmem_cache_create("netfs_subrequest", 118 sizeof(struct netfs_io_subrequest), 0, 119 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 120 NULL); 121 if (!netfs_subrequest_slab) 122 goto error_subreq; 123 124 if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0) 125 goto error_subreqpool; 126 127 if (!proc_mkdir("fs/netfs", NULL)) 128 goto error_proc; 129 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, 130 &netfs_requests_seq_ops)) 131 goto error_procfile; 132 #ifdef CONFIG_FSCACHE_STATS 133 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, 134 netfs_stats_show)) 135 goto error_procfile; 136 #endif 137 138 ret = fscache_init(); 139 if (ret < 0) 140 goto error_fscache; 141 return 0; 142 143 error_fscache: 144 error_procfile: 145 remove_proc_entry("fs/netfs", NULL); 146 error_proc: 147 mempool_exit(&netfs_subrequest_pool); 148 error_subreqpool: 149 kmem_cache_destroy(netfs_subrequest_slab); 150 error_subreq: 151 mempool_exit(&netfs_request_pool); 152 error_reqpool: 153 kmem_cache_destroy(netfs_request_slab); 154 error_req: 155 return ret; 156 } 157 fs_initcall(netfs_init); 158 159 static void __exit netfs_exit(void) 160 { 161 fscache_exit(); 162 remove_proc_entry("fs/netfs", NULL); 163 mempool_exit(&netfs_subrequest_pool); 164 kmem_cache_destroy(netfs_subrequest_slab); 165 mempool_exit(&netfs_request_pool); 166 kmem_cache_destroy(netfs_request_slab); 167 } 168 module_exit(netfs_exit); 169