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