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/proc_fs.h> 11#include <linux/seq_file.h> 12#include "internal.h" 13#define CREATE_TRACE_POINTS 14#include <trace/events/netfs.h> 15 16MODULE_DESCRIPTION("Network fs support"); 17MODULE_AUTHOR("Red Hat, Inc."); 18MODULE_LICENSE("GPL"); 19 20EXPORT_TRACEPOINT_SYMBOL(netfs_sreq); 21 22unsigned netfs_debug; 23module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); 24MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); 25 26#ifdef CONFIG_PROC_FS 27LIST_HEAD(netfs_io_requests); 28DEFINE_SPINLOCK(netfs_proc_lock); 29 30static const char *netfs_origins[nr__netfs_io_origin] = { 31 [NETFS_READAHEAD] = "RA", 32 [NETFS_READPAGE] = "RP", 33 [NETFS_READ_FOR_WRITE] = "RW", 34 [NETFS_WRITEBACK] = "WB", 35 [NETFS_WRITETHROUGH] = "WT", 36 [NETFS_LAUNDER_WRITE] = "LW", 37 [NETFS_UNBUFFERED_WRITE] = "UW", 38 [NETFS_DIO_READ] = "DR", 39 [NETFS_DIO_WRITE] = "DW", 40}; 41 42/* 43 * Generate a list of I/O requests in /proc/fs/netfs/requests 44 */ 45static int netfs_requests_seq_show(struct seq_file *m, void *v) 46{ 47 struct netfs_io_request *rreq; 48 49 if (v == &netfs_io_requests) { 50 seq_puts(m, 51 "REQUEST OR REF FL ERR OPS COVERAGE\n" 52 "======== == === == ==== === =========\n" 53 ); 54 return 0; 55 } 56 57 rreq = list_entry(v, struct netfs_io_request, proc_link); 58 seq_printf(m, 59 "%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx", 60 rreq->debug_id, 61 netfs_origins[rreq->origin], 62 refcount_read(&rreq->ref), 63 rreq->flags, 64 rreq->error, 65 atomic_read(&rreq->nr_outstanding), 66 rreq->start, rreq->submitted, rreq->len); 67 seq_putc(m, '\n'); 68 return 0; 69} 70 71static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) 72 __acquires(rcu) 73{ 74 rcu_read_lock(); 75 return seq_list_start_head(&netfs_io_requests, *_pos); 76} 77 78static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) 79{ 80 return seq_list_next(v, &netfs_io_requests, _pos); 81} 82 83static void netfs_requests_seq_stop(struct seq_file *m, void *v) 84 __releases(rcu) 85{ 86 rcu_read_unlock(); 87} 88 89static const struct seq_operations netfs_requests_seq_ops = { 90 .start = netfs_requests_seq_start, 91 .next = netfs_requests_seq_next, 92 .stop = netfs_requests_seq_stop, 93 .show = netfs_requests_seq_show, 94}; 95#endif /* CONFIG_PROC_FS */ 96 97static int __init netfs_init(void) 98{ 99 int ret = -ENOMEM; 100 101 if (!proc_mkdir("fs/netfs", NULL)) 102 goto error; 103 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, 104 &netfs_requests_seq_ops)) 105 goto error_proc; 106#ifdef CONFIG_FSCACHE_STATS 107 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, 108 netfs_stats_show)) 109 goto error_proc; 110#endif 111 112 ret = fscache_init(); 113 if (ret < 0) 114 goto error_proc; 115 return 0; 116 117error_proc: 118 remove_proc_entry("fs/netfs", NULL); 119error: 120 return ret; 121} 122fs_initcall(netfs_init); 123 124static void __exit netfs_exit(void) 125{ 126 fscache_exit(); 127 remove_proc_entry("fs/netfs", NULL); 128} 129module_exit(netfs_exit); 130