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 mempool_t netfs_folioq_pool; 32 33 #ifdef CONFIG_PROC_FS 34 LIST_HEAD(netfs_io_requests); 35 DEFINE_SPINLOCK(netfs_proc_lock); 36 37 static const char *netfs_origins[nr__netfs_io_origin] = { 38 [NETFS_READAHEAD] = "RA", 39 [NETFS_READPAGE] = "RP", 40 [NETFS_READ_GAPS] = "RG", 41 [NETFS_READ_SINGLE] = "R1", 42 [NETFS_READ_FOR_WRITE] = "RW", 43 [NETFS_UNBUFFERED_READ] = "UR", 44 [NETFS_DIO_READ] = "DR", 45 [NETFS_WRITEBACK] = "WB", 46 [NETFS_WRITEBACK_SINGLE] = "W1", 47 [NETFS_UNBUFFERED_WRITE] = "UW", 48 [NETFS_DIO_WRITE] = "DW", 49 [NETFS_PGPRIV2_COPY_TO_CACHE] = "2C", 50 }; 51 52 /* 53 * Generate a list of I/O requests in /proc/fs/netfs/requests 54 */ 55 static int netfs_requests_seq_show(struct seq_file *m, void *v) 56 { 57 struct netfs_io_request *rreq; 58 59 if (v == &netfs_io_requests) { 60 seq_puts(m, 61 "REQUEST OR REF FLAG ERR OPS COVERAGE\n" 62 "======== == === ==== ==== === =========\n" 63 ); 64 return 0; 65 } 66 67 rreq = list_entry(v, struct netfs_io_request, proc_link); 68 seq_printf(m, 69 "%08x %s %3d %4lx %4ld %3d @%04llx %llx/%llx", 70 rreq->debug_id, 71 netfs_origins[rreq->origin], 72 refcount_read(&rreq->ref), 73 rreq->flags, 74 rreq->error, 75 0, 76 rreq->start, rreq->submitted, rreq->len); 77 seq_putc(m, '\n'); 78 return 0; 79 } 80 81 static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) 82 __acquires(rcu) 83 { 84 rcu_read_lock(); 85 return seq_list_start_head(&netfs_io_requests, *_pos); 86 } 87 88 static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) 89 { 90 return seq_list_next(v, &netfs_io_requests, _pos); 91 } 92 93 static void netfs_requests_seq_stop(struct seq_file *m, void *v) 94 __releases(rcu) 95 { 96 rcu_read_unlock(); 97 } 98 99 static const struct seq_operations netfs_requests_seq_ops = { 100 .start = netfs_requests_seq_start, 101 .next = netfs_requests_seq_next, 102 .stop = netfs_requests_seq_stop, 103 .show = netfs_requests_seq_show, 104 }; 105 #endif /* CONFIG_PROC_FS */ 106 107 static int __init netfs_init(void) 108 { 109 int ret = -ENOMEM; 110 111 if (mempool_init_kmalloc_pool(&netfs_folioq_pool, 100, sizeof(struct folio_queue)) < 0) 112 goto error_folioq_pool; 113 114 netfs_request_slab = kmem_cache_create("netfs_request", 115 sizeof(struct netfs_io_request), 0, 116 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 117 NULL); 118 if (!netfs_request_slab) 119 goto error_req; 120 121 if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0) 122 goto error_reqpool; 123 124 netfs_subrequest_slab = kmem_cache_create("netfs_subrequest", 125 sizeof(struct netfs_io_subrequest) + 16, 0, 126 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 127 NULL); 128 if (!netfs_subrequest_slab) 129 goto error_subreq; 130 131 if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0) 132 goto error_subreqpool; 133 134 #ifdef CONFIG_PROC_FS 135 if (!proc_mkdir("fs/netfs", NULL)) 136 goto error_proc; 137 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, 138 &netfs_requests_seq_ops)) 139 goto error_procfile; 140 #endif 141 #ifdef CONFIG_FSCACHE_STATS 142 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, 143 netfs_stats_show)) 144 goto error_procfile; 145 #endif 146 147 ret = fscache_init(); 148 if (ret < 0) 149 goto error_fscache; 150 return 0; 151 152 error_fscache: 153 #ifdef CONFIG_PROC_FS 154 error_procfile: 155 remove_proc_subtree("fs/netfs", NULL); 156 error_proc: 157 #endif 158 mempool_exit(&netfs_subrequest_pool); 159 error_subreqpool: 160 kmem_cache_destroy(netfs_subrequest_slab); 161 error_subreq: 162 mempool_exit(&netfs_request_pool); 163 error_reqpool: 164 kmem_cache_destroy(netfs_request_slab); 165 error_req: 166 mempool_exit(&netfs_folioq_pool); 167 error_folioq_pool: 168 return ret; 169 } 170 fs_initcall(netfs_init); 171 172 static void __exit netfs_exit(void) 173 { 174 fscache_exit(); 175 remove_proc_subtree("fs/netfs", NULL); 176 mempool_exit(&netfs_subrequest_pool); 177 kmem_cache_destroy(netfs_subrequest_slab); 178 mempool_exit(&netfs_request_pool); 179 kmem_cache_destroy(netfs_request_slab); 180 mempool_exit(&netfs_folioq_pool); 181 } 182 module_exit(netfs_exit); 183