summaryrefslogtreecommitdiffstats
path: root/fs/netfs/objects.c
blob: 657b19e6011857d7b7683477a3e940bcb7f50cf5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// SPDX-License-Identifier: GPL-2.0-only
/* Object lifetime handling and tracing.
 *
 * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/slab.h>
#include "internal.h"

/*
 * Allocate an I/O request and initialise it.
 */
struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
					     struct file *file,
					     loff_t start, size_t len,
					     enum netfs_io_origin origin)
{
	static atomic_t debug_ids;
	struct inode *inode = file ? file_inode(file) : mapping->host;
	struct netfs_i_context *ctx = netfs_i_context(inode);
	struct netfs_io_request *rreq;
	int ret;

	rreq = kzalloc(sizeof(struct netfs_io_request), GFP_KERNEL);
	if (!rreq)
		return ERR_PTR(-ENOMEM);

	rreq->start	= start;
	rreq->len	= len;
	rreq->origin	= origin;
	rreq->netfs_ops	= ctx->ops;
	rreq->mapping	= mapping;
	rreq->inode	= inode;
	rreq->i_size	= i_size_read(inode);
	rreq->debug_id	= atomic_inc_return(&debug_ids);
	INIT_LIST_HEAD(&rreq->subrequests);
	INIT_WORK(&rreq->work, netfs_rreq_work);
	refcount_set(&rreq->ref, 1);
	__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
	if (rreq->netfs_ops->init_request) {
		ret = rreq->netfs_ops->init_request(rreq, file);
		if (ret < 0) {
			kfree(rreq);
			return ERR_PTR(ret);
		}
	}

	netfs_stat(&netfs_n_rh_rreq);
	return rreq;
}

void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what)
{
	int r;

	__refcount_inc(&rreq->ref, &r);
	trace_netfs_rreq_ref(rreq->debug_id, r + 1, what);
}

void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
{
	struct netfs_io_subrequest *subreq;

	while (!list_empty(&rreq->subrequests)) {
		subreq = list_first_entry(&rreq->subrequests,
					  struct netfs_io_subrequest, rreq_link);
		list_del(&subreq->rreq_link);
		netfs_put_subrequest(subreq, was_async,
				     netfs_sreq_trace_put_clear);
	}
}

static void netfs_free_request(struct work_struct *work)
{
	struct netfs_io_request *rreq =
		container_of(work, struct netfs_io_request, work);

	netfs_clear_subrequests(rreq, false);
	if (rreq->netfs_priv)
		rreq->netfs_ops->cleanup(rreq->mapping, rreq->netfs_priv);
	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
	if (rreq->cache_resources.ops)
		rreq->cache_resources.ops->end_operation(&rreq->cache_resources);
	kfree(rreq);
	netfs_stat_d(&netfs_n_rh_rreq);
}

void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
		       enum netfs_rreq_ref_trace what)
{
	unsigned int debug_id = rreq->debug_id;
	bool dead;
	int r;

	dead = __refcount_dec_and_test(&rreq->ref, &r);
	trace_netfs_rreq_ref(debug_id, r - 1, what);
	if (dead) {
		if (was_async) {
			rreq->work.func = netfs_free_request;
			if (!queue_work(system_unbound_wq, &rreq->work))
				BUG();
		} else {
			netfs_free_request(&rreq->work);
		}
	}
}

/*
 * Allocate and partially initialise an I/O request structure.
 */
struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq)
{
	struct netfs_io_subrequest *subreq;

	subreq = kzalloc(sizeof(struct netfs_io_subrequest), GFP_KERNEL);
	if (subreq) {
		INIT_LIST_HEAD(&subreq->rreq_link);
		refcount_set(&subreq->ref, 2);
		subreq->rreq = rreq;
		netfs_get_request(rreq, netfs_rreq_trace_get_subreq);
		netfs_stat(&netfs_n_rh_sreq);
	}

	return subreq;
}

void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
			  enum netfs_sreq_ref_trace what)
{
	int r;

	__refcount_inc(&subreq->ref, &r);
	trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, r + 1,
			     what);
}

static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
				  bool was_async)
{
	struct netfs_io_request *rreq = subreq->rreq;

	trace_netfs_sreq(subreq, netfs_sreq_trace_free);
	kfree(subreq);
	netfs_stat_d(&netfs_n_rh_sreq);
	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
}

void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
			  enum netfs_sreq_ref_trace what)
{
	unsigned int debug_index = subreq->debug_index;
	unsigned int debug_id = subreq->rreq->debug_id;
	bool dead;
	int r;

	dead = __refcount_dec_and_test(&subreq->ref, &r);
	trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what);
	if (dead)
		netfs_free_subrequest(subreq, was_async);
}