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