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_WRITETHROUGH] = "WT",
48 [NETFS_UNBUFFERED_WRITE] = "UW",
49 [NETFS_DIO_WRITE] = "DW",
50 [NETFS_PGPRIV2_COPY_TO_CACHE] = "2C",
51 };
52
53 /*
54 * Generate a list of I/O requests in /proc/fs/netfs/requests
55 */
netfs_requests_seq_show(struct seq_file * m,void * v)56 static int netfs_requests_seq_show(struct seq_file *m, void *v)
57 {
58 struct netfs_io_request *rreq;
59
60 if (v == &netfs_io_requests) {
61 seq_puts(m,
62 "REQUEST OR REF FLAG ERR OPS COVERAGE\n"
63 "======== == === ==== ==== === =========\n"
64 );
65 return 0;
66 }
67
68 rreq = list_entry(v, struct netfs_io_request, proc_link);
69 seq_printf(m,
70 "%08x %s %3d %4lx %4ld %3d @%04llx %llx/%llx",
71 rreq->debug_id,
72 netfs_origins[rreq->origin],
73 refcount_read(&rreq->ref),
74 rreq->flags,
75 rreq->error,
76 0,
77 rreq->start, rreq->submitted, rreq->len);
78 seq_putc(m, '\n');
79 return 0;
80 }
81
netfs_requests_seq_start(struct seq_file * m,loff_t * _pos)82 static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos)
83 __acquires(rcu)
84 {
85 rcu_read_lock();
86 return seq_list_start_head(&netfs_io_requests, *_pos);
87 }
88
netfs_requests_seq_next(struct seq_file * m,void * v,loff_t * _pos)89 static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos)
90 {
91 return seq_list_next(v, &netfs_io_requests, _pos);
92 }
93
netfs_requests_seq_stop(struct seq_file * m,void * v)94 static void netfs_requests_seq_stop(struct seq_file *m, void *v)
95 __releases(rcu)
96 {
97 rcu_read_unlock();
98 }
99
100 static const struct seq_operations netfs_requests_seq_ops = {
101 .start = netfs_requests_seq_start,
102 .next = netfs_requests_seq_next,
103 .stop = netfs_requests_seq_stop,
104 .show = netfs_requests_seq_show,
105 };
106 #endif /* CONFIG_PROC_FS */
107
netfs_init(void)108 static int __init netfs_init(void)
109 {
110 int ret = -ENOMEM;
111
112 if (mempool_init_kmalloc_pool(&netfs_folioq_pool, 100, sizeof(struct folio_queue)) < 0)
113 goto error_folioq_pool;
114
115 netfs_request_slab = kmem_cache_create("netfs_request",
116 sizeof(struct netfs_io_request), 0,
117 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
118 NULL);
119 if (!netfs_request_slab)
120 goto error_req;
121
122 if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0)
123 goto error_reqpool;
124
125 netfs_subrequest_slab = kmem_cache_create("netfs_subrequest",
126 sizeof(struct netfs_io_subrequest) + 16, 0,
127 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
128 NULL);
129 if (!netfs_subrequest_slab)
130 goto error_subreq;
131
132 if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0)
133 goto error_subreqpool;
134
135 #ifdef CONFIG_PROC_FS
136 if (!proc_mkdir("fs/netfs", NULL))
137 goto error_proc;
138 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
139 &netfs_requests_seq_ops))
140 goto error_procfile;
141 #endif
142 #ifdef CONFIG_FSCACHE_STATS
143 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
144 netfs_stats_show))
145 goto error_procfile;
146 #endif
147
148 ret = fscache_init();
149 if (ret < 0)
150 goto error_fscache;
151 return 0;
152
153 error_fscache:
154 #ifdef CONFIG_PROC_FS
155 error_procfile:
156 remove_proc_subtree("fs/netfs", NULL);
157 error_proc:
158 #endif
159 mempool_exit(&netfs_subrequest_pool);
160 error_subreqpool:
161 kmem_cache_destroy(netfs_subrequest_slab);
162 error_subreq:
163 mempool_exit(&netfs_request_pool);
164 error_reqpool:
165 kmem_cache_destroy(netfs_request_slab);
166 error_req:
167 mempool_exit(&netfs_folioq_pool);
168 error_folioq_pool:
169 return ret;
170 }
171 fs_initcall(netfs_init);
172
netfs_exit(void)173 static void __exit netfs_exit(void)
174 {
175 fscache_exit();
176 remove_proc_subtree("fs/netfs", NULL);
177 mempool_exit(&netfs_subrequest_pool);
178 kmem_cache_destroy(netfs_subrequest_slab);
179 mempool_exit(&netfs_request_pool);
180 kmem_cache_destroy(netfs_request_slab);
181 mempool_exit(&netfs_folioq_pool);
182 }
183 module_exit(netfs_exit);
184