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 */
netfs_requests_seq_show(struct seq_file * m,void * v)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
netfs_requests_seq_start(struct seq_file * m,loff_t * _pos)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
netfs_requests_seq_next(struct seq_file * m,void * v,loff_t * _pos)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
netfs_requests_seq_stop(struct seq_file * m,void * v)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
netfs_init(void)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
netfs_exit(void)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