1// SPDX-License-Identifier: GPL-2.0-only
2/* Object lifetime handling and tracing.
3 *
4 * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/slab.h>
9#include "internal.h"
10
11/*
12 * Allocate an I/O request and initialise it.
13 */
14struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
15 struct file *file,
16 loff_t start, size_t len,
17 enum netfs_io_origin origin)
18{
19 static atomic_t debug_ids;
20 struct inode *inode = file ? file_inode(f: file) : mapping->host;
21 struct netfs_inode *ctx = netfs_inode(inode);
22 struct netfs_io_request *rreq;
23 bool is_unbuffered = (origin == NETFS_UNBUFFERED_WRITE ||
24 origin == NETFS_DIO_READ ||
25 origin == NETFS_DIO_WRITE);
26 bool cached = !is_unbuffered && netfs_is_cache_enabled(ctx);
27 int ret;
28
29 rreq = kzalloc(size: ctx->ops->io_request_size ?: sizeof(struct netfs_io_request),
30 GFP_KERNEL);
31 if (!rreq)
32 return ERR_PTR(error: -ENOMEM);
33
34 rreq->start = start;
35 rreq->len = len;
36 rreq->upper_len = len;
37 rreq->origin = origin;
38 rreq->netfs_ops = ctx->ops;
39 rreq->mapping = mapping;
40 rreq->inode = inode;
41 rreq->i_size = i_size_read(inode);
42 rreq->debug_id = atomic_inc_return(v: &debug_ids);
43 INIT_LIST_HEAD(list: &rreq->subrequests);
44 INIT_WORK(&rreq->work, NULL);
45 refcount_set(r: &rreq->ref, n: 1);
46
47 __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
48 if (cached)
49 __set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags);
50 if (file && file->f_flags & O_NONBLOCK)
51 __set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags);
52 if (rreq->netfs_ops->init_request) {
53 ret = rreq->netfs_ops->init_request(rreq, file);
54 if (ret < 0) {
55 kfree(objp: rreq);
56 return ERR_PTR(error: ret);
57 }
58 }
59
60 trace_netfs_rreq_ref(rreq_debug_id: rreq->debug_id, ref: 1, what: netfs_rreq_trace_new);
61 netfs_proc_add_rreq(rreq);
62 netfs_stat(stat: &netfs_n_rh_rreq);
63 return rreq;
64}
65
66void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what)
67{
68 int r;
69
70 __refcount_inc(r: &rreq->ref, oldp: &r);
71 trace_netfs_rreq_ref(rreq_debug_id: rreq->debug_id, ref: r + 1, what);
72}
73
74void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
75{
76 struct netfs_io_subrequest *subreq;
77
78 while (!list_empty(head: &rreq->subrequests)) {
79 subreq = list_first_entry(&rreq->subrequests,
80 struct netfs_io_subrequest, rreq_link);
81 list_del(entry: &subreq->rreq_link);
82 netfs_put_subrequest(subreq, was_async,
83 what: netfs_sreq_trace_put_clear);
84 }
85}
86
87static void netfs_free_request(struct work_struct *work)
88{
89 struct netfs_io_request *rreq =
90 container_of(work, struct netfs_io_request, work);
91 unsigned int i;
92
93 trace_netfs_rreq(rreq, what: netfs_rreq_trace_free);
94 netfs_proc_del_rreq(rreq);
95 netfs_clear_subrequests(rreq, was_async: false);
96 if (rreq->netfs_ops->free_request)
97 rreq->netfs_ops->free_request(rreq);
98 if (rreq->cache_resources.ops)
99 rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
100 if (rreq->direct_bv) {
101 for (i = 0; i < rreq->direct_bv_count; i++) {
102 if (rreq->direct_bv[i].bv_page) {
103 if (rreq->direct_bv_unpin)
104 unpin_user_page(page: rreq->direct_bv[i].bv_page);
105 }
106 }
107 kvfree(addr: rreq->direct_bv);
108 }
109 kfree_rcu(rreq, rcu);
110 netfs_stat_d(stat: &netfs_n_rh_rreq);
111}
112
113void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
114 enum netfs_rreq_ref_trace what)
115{
116 unsigned int debug_id;
117 bool dead;
118 int r;
119
120 if (rreq) {
121 debug_id = rreq->debug_id;
122 dead = __refcount_dec_and_test(r: &rreq->ref, oldp: &r);
123 trace_netfs_rreq_ref(rreq_debug_id: debug_id, ref: r - 1, what);
124 if (dead) {
125 if (was_async) {
126 rreq->work.func = netfs_free_request;
127 if (!queue_work(wq: system_unbound_wq, work: &rreq->work))
128 BUG();
129 } else {
130 netfs_free_request(work: &rreq->work);
131 }
132 }
133 }
134}
135
136/*
137 * Allocate and partially initialise an I/O request structure.
138 */
139struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq)
140{
141 struct netfs_io_subrequest *subreq;
142
143 subreq = kzalloc(size: rreq->netfs_ops->io_subrequest_size ?:
144 sizeof(struct netfs_io_subrequest),
145 GFP_KERNEL);
146 if (subreq) {
147 INIT_WORK(&subreq->work, NULL);
148 INIT_LIST_HEAD(list: &subreq->rreq_link);
149 refcount_set(r: &subreq->ref, n: 2);
150 subreq->rreq = rreq;
151 netfs_get_request(rreq, what: netfs_rreq_trace_get_subreq);
152 netfs_stat(stat: &netfs_n_rh_sreq);
153 }
154
155 return subreq;
156}
157
158void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
159 enum netfs_sreq_ref_trace what)
160{
161 int r;
162
163 __refcount_inc(r: &subreq->ref, oldp: &r);
164 trace_netfs_sreq_ref(rreq_debug_id: subreq->rreq->debug_id, subreq_debug_index: subreq->debug_index, ref: r + 1,
165 what);
166}
167
168static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
169 bool was_async)
170{
171 struct netfs_io_request *rreq = subreq->rreq;
172
173 trace_netfs_sreq(sreq: subreq, what: netfs_sreq_trace_free);
174 if (rreq->netfs_ops->free_subrequest)
175 rreq->netfs_ops->free_subrequest(subreq);
176 kfree(objp: subreq);
177 netfs_stat_d(stat: &netfs_n_rh_sreq);
178 netfs_put_request(rreq, was_async, what: netfs_rreq_trace_put_subreq);
179}
180
181void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
182 enum netfs_sreq_ref_trace what)
183{
184 unsigned int debug_index = subreq->debug_index;
185 unsigned int debug_id = subreq->rreq->debug_id;
186 bool dead;
187 int r;
188
189 dead = __refcount_dec_and_test(r: &subreq->ref, oldp: &r);
190 trace_netfs_sreq_ref(rreq_debug_id: debug_id, subreq_debug_index: debug_index, ref: r - 1, what);
191 if (dead)
192 netfs_free_subrequest(subreq, was_async);
193}
194

source code of linux/fs/netfs/objects.c