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 static struct kmem_cache *netfs_request_slab; 24 static struct kmem_cache *netfs_subrequest_slab; 25 mempool_t netfs_request_pool; 26 mempool_t netfs_subrequest_pool; 27 28 #ifdef CONFIG_PROC_FS 29 LIST_HEAD(netfs_io_requests); 30 DEFINE_SPINLOCK(netfs_proc_lock); 31 32 static const char *netfs_origins[nr__netfs_io_origin] = { 33 [NETFS_READAHEAD] = "RA", 34 [NETFS_READPAGE] = "RP", 35 [NETFS_READ_FOR_WRITE] = "RW", 36 [NETFS_COPY_TO_CACHE] = "CC", 37 [NETFS_WRITEBACK] = "WB", 38 [NETFS_WRITETHROUGH] = "WT", 39 [NETFS_UNBUFFERED_WRITE] = "UW", 40 [NETFS_DIO_READ] = "DR", 41 [NETFS_DIO_WRITE] = "DW", 42 }; 43 44 /* 45 * Generate a list of I/O requests in /proc/fs/netfs/requests 46 */ 47 static int netfs_requests_seq_show(struct seq_file *m, void *v) 48 { 49 struct netfs_io_request *rreq; 50 51 if (v == &netfs_io_requests) { 52 seq_puts(m, 53 "REQUEST OR REF FL ERR OPS COVERAGE\n" 54 "======== == === == ==== === =========\n" 55 ); 56 return 0; 57 } 58 59 rreq = list_entry(v, struct netfs_io_request, proc_link); 60 seq_printf(m, 61 "%08x %s %3d %2lx %4d %3d @%04llx %llx/%llx", 62 rreq->debug_id, 63 netfs_origins[rreq->origin], 64 refcount_read(&rreq->ref), 65 rreq->flags, 66 rreq->error, 67 atomic_read(&rreq->nr_outstanding), 68 rreq->start, rreq->submitted, rreq->len); 69 seq_putc(m, '\n'); 70 return 0; 71 } 72 73 static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) 74 __acquires(rcu) 75 { 76 rcu_read_lock(); 77 return seq_list_start_head(&netfs_io_requests, *_pos); 78 } 79 80 static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) 81 { 82 return seq_list_next(v, &netfs_io_requests, _pos); 83 } 84 85 static void netfs_requests_seq_stop(struct seq_file *m, void *v) 86 __releases(rcu) 87 { 88 rcu_read_unlock(); 89 } 90 91 static const struct seq_operations netfs_requests_seq_ops = { 92 .start = netfs_requests_seq_start, 93 .next = netfs_requests_seq_next, 94 .stop = netfs_requests_seq_stop, 95 .show = netfs_requests_seq_show, 96 }; 97 #endif /* CONFIG_PROC_FS */ 98 99 static int __init netfs_init(void) 100 { 101 int ret = -ENOMEM; 102 103 netfs_request_slab = kmem_cache_create("netfs_request", 104 sizeof(struct netfs_io_request), 0, 105 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 106 NULL); 107 if (!netfs_request_slab) 108 goto error_req; 109 110 if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0) 111 goto error_reqpool; 112 113 netfs_subrequest_slab = kmem_cache_create("netfs_subrequest", 114 sizeof(struct netfs_io_subrequest), 0, 115 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 116 NULL); 117 if (!netfs_subrequest_slab) 118 goto error_subreq; 119 120 if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0) 121 goto error_subreqpool; 122 123 if (!proc_mkdir("fs/netfs", NULL)) 124 goto error_proc; 125 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, 126 &netfs_requests_seq_ops)) 127 goto error_procfile; 128 #ifdef CONFIG_FSCACHE_STATS 129 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, 130 netfs_stats_show)) 131 goto error_procfile; 132 #endif 133 134 ret = fscache_init(); 135 if (ret < 0) 136 goto error_fscache; 137 return 0; 138 139 error_fscache: 140 error_procfile: 141 remove_proc_entry("fs/netfs", NULL); 142 error_proc: 143 mempool_exit(&netfs_subrequest_pool); 144 error_subreqpool: 145 kmem_cache_destroy(netfs_subrequest_slab); 146 error_subreq: 147 mempool_exit(&netfs_request_pool); 148 error_reqpool: 149 kmem_cache_destroy(netfs_request_slab); 150 error_req: 151 return ret; 152 } 153 fs_initcall(netfs_init); 154 155 static void __exit netfs_exit(void) 156 { 157 fscache_exit(); 158 remove_proc_entry("fs/netfs", NULL); 159 mempool_exit(&netfs_subrequest_pool); 160 kmem_cache_destroy(netfs_subrequest_slab); 161 mempool_exit(&netfs_request_pool); 162 kmem_cache_destroy(netfs_request_slab); 163 } 164 module_exit(netfs_exit); 165