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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
17MODULE_DESCRIPTION("Network fs support");
18MODULE_AUTHOR("Red Hat, Inc.");
19MODULE_LICENSE("GPL");
20
21EXPORT_TRACEPOINT_SYMBOL(netfs_sreq);
22
23unsigned netfs_debug;
24module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
25MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
26
27static struct kmem_cache *netfs_request_slab;
28static struct kmem_cache *netfs_subrequest_slab;
29mempool_t netfs_request_pool;
30mempool_t netfs_subrequest_pool;
31
32#ifdef CONFIG_PROC_FS
33LIST_HEAD(netfs_io_requests);
34DEFINE_SPINLOCK(netfs_proc_lock);
35
36static 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_UNBUFFERED_READ] = "UR",
43 [NETFS_DIO_READ] = "DR",
44 [NETFS_WRITEBACK] = "WB",
45 [NETFS_WRITEBACK_SINGLE] = "W1",
46 [NETFS_WRITETHROUGH] = "WT",
47 [NETFS_UNBUFFERED_WRITE] = "UW",
48 [NETFS_DIO_WRITE] = "DW",
49 [NETFS_PGPRIV2_COPY_TO_CACHE] = "2C",
50};
51
52/*
53 * Generate a list of I/O requests in /proc/fs/netfs/requests
54 */
55static int netfs_requests_seq_show(struct seq_file *m, void *v)
56{
57 struct netfs_io_request *rreq;
58
59 if (v == &netfs_io_requests) {
60 seq_puts(m,
61 "REQUEST OR REF FLAG ERR OPS COVERAGE\n"
62 "======== == === ==== ==== === =========\n"
63 );
64 return 0;
65 }
66
67 rreq = list_entry(v, struct netfs_io_request, proc_link);
68 seq_printf(m,
69 "%08x %s %3d %4lx %4ld %3d @%04llx %llx/%llx",
70 rreq->debug_id,
71 netfs_origins[rreq->origin],
72 refcount_read(&rreq->ref),
73 rreq->flags,
74 rreq->error,
75 0,
76 rreq->start, rreq->submitted, rreq->len);
77 seq_putc(m, '\n');
78 return 0;
79}
80
81static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos)
82 __acquires(rcu)
83{
84 rcu_read_lock();
85 return seq_list_start_head(&netfs_io_requests, *_pos);
86}
87
88static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos)
89{
90 return seq_list_next(v, &netfs_io_requests, _pos);
91}
92
93static void netfs_requests_seq_stop(struct seq_file *m, void *v)
94 __releases(rcu)
95{
96 rcu_read_unlock();
97}
98
99static const struct seq_operations netfs_requests_seq_ops = {
100 .start = netfs_requests_seq_start,
101 .next = netfs_requests_seq_next,
102 .stop = netfs_requests_seq_stop,
103 .show = netfs_requests_seq_show,
104};
105#endif /* CONFIG_PROC_FS */
106
107static int __init netfs_init(void)
108{
109 int ret = -ENOMEM;
110
111 netfs_request_slab = kmem_cache_create("netfs_request",
112 sizeof(struct netfs_io_request), 0,
113 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
114 NULL);
115 if (!netfs_request_slab)
116 goto error_req;
117
118 if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0)
119 goto error_reqpool;
120
121 netfs_subrequest_slab = kmem_cache_create("netfs_subrequest",
122 sizeof(struct netfs_io_subrequest) + 16, 0,
123 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
124 NULL);
125 if (!netfs_subrequest_slab)
126 goto error_subreq;
127
128 if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0)
129 goto error_subreqpool;
130
131#ifdef CONFIG_PROC_FS
132 if (!proc_mkdir("fs/netfs", NULL))
133 goto error_proc;
134 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
135 &netfs_requests_seq_ops))
136 goto error_procfile;
137#endif
138#ifdef CONFIG_FSCACHE_STATS
139 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
140 netfs_stats_show))
141 goto error_procfile;
142#endif
143
144 ret = fscache_init();
145 if (ret < 0)
146 goto error_fscache;
147 return 0;
148
149error_fscache:
150#ifdef CONFIG_PROC_FS
151error_procfile:
152 remove_proc_subtree("fs/netfs", NULL);
153error_proc:
154#endif
155 mempool_exit(&netfs_subrequest_pool);
156error_subreqpool:
157 kmem_cache_destroy(netfs_subrequest_slab);
158error_subreq:
159 mempool_exit(&netfs_request_pool);
160error_reqpool:
161 kmem_cache_destroy(netfs_request_slab);
162error_req:
163 return ret;
164}
165fs_initcall(netfs_init);
166
167static void __exit netfs_exit(void)
168{
169 fscache_exit();
170 remove_proc_subtree("fs/netfs", NULL);
171 mempool_exit(&netfs_subrequest_pool);
172 kmem_cache_destroy(netfs_subrequest_slab);
173 mempool_exit(&netfs_request_pool);
174 kmem_cache_destroy(netfs_request_slab);
175}
176module_exit(netfs_exit);