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