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
162
163
164
165
166
167
168
169
170
|
// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "librbd/io/ReadResult.h"
#include "include/buffer.h"
#include "common/dout.h"
#include "librbd/io/AioCompletion.h"
#include <boost/variant/apply_visitor.hpp>
#include <boost/variant/static_visitor.hpp>
#define dout_subsys ceph_subsys_rbd
#undef dout_prefix
#define dout_prefix *_dout << "librbd::io::ReadResult: " << this \
<< " " << __func__ << ": "
namespace librbd {
namespace io {
struct ReadResult::SetClipLengthVisitor : public boost::static_visitor<void> {
size_t length;
explicit SetClipLengthVisitor(size_t length) : length(length) {
}
void operator()(Linear &linear) const {
ceph_assert(length <= linear.buf_len);
linear.buf_len = length;
}
template <typename T>
void operator()(T &t) const {
}
};
struct ReadResult::AssembleResultVisitor : public boost::static_visitor<void> {
CephContext *cct;
Striper::StripedReadResult &destriper;
AssembleResultVisitor(CephContext *cct, Striper::StripedReadResult &destriper)
: cct(cct), destriper(destriper) {
}
void operator()(Empty &empty) const {
ldout(cct, 20) << "dropping read result" << dendl;
}
void operator()(Linear &linear) const {
ldout(cct, 20) << "copying resulting bytes to "
<< reinterpret_cast<void*>(linear.buf) << dendl;
destriper.assemble_result(cct, linear.buf, linear.buf_len);
}
void operator()(Vector &vector) const {
bufferlist bl;
destriper.assemble_result(cct, bl, true);
ldout(cct, 20) << "copying resulting " << bl.length() << " bytes to iovec "
<< reinterpret_cast<const void*>(vector.iov) << dendl;
bufferlist::iterator it = bl.begin();
size_t length = bl.length();
size_t offset = 0;
int idx = 0;
for (; offset < length && idx < vector.iov_count; idx++) {
size_t len = std::min(vector.iov[idx].iov_len, length - offset);
it.copy(len, static_cast<char *>(vector.iov[idx].iov_base));
offset += len;
}
ceph_assert(offset == bl.length());
}
void operator()(Bufferlist &bufferlist) const {
bufferlist.bl->clear();
destriper.assemble_result(cct, *bufferlist.bl, true);
ldout(cct, 20) << "moved resulting " << bufferlist.bl->length() << " "
<< "bytes to bl " << reinterpret_cast<void*>(bufferlist.bl)
<< dendl;
}
};
ReadResult::C_ImageReadRequest::C_ImageReadRequest(
AioCompletion *aio_completion, const Extents image_extents)
: aio_completion(aio_completion), image_extents(image_extents) {
aio_completion->add_request();
}
void ReadResult::C_ImageReadRequest::finish(int r) {
CephContext *cct = aio_completion->ictx->cct;
ldout(cct, 10) << "C_ImageReadRequest: r=" << r
<< dendl;
if (r >= 0) {
size_t length = 0;
for (auto &image_extent : image_extents) {
length += image_extent.second;
}
ceph_assert(length == bl.length());
aio_completion->lock.Lock();
aio_completion->read_result.m_destriper.add_partial_result(
cct, bl, image_extents);
aio_completion->lock.Unlock();
r = length;
}
aio_completion->complete_request(r);
}
ReadResult::C_ObjectReadRequest::C_ObjectReadRequest(
AioCompletion *aio_completion, uint64_t object_off, uint64_t object_len,
Extents&& buffer_extents)
: aio_completion(aio_completion), object_off(object_off),
object_len(object_len), buffer_extents(std::move(buffer_extents)) {
aio_completion->add_request();
}
void ReadResult::C_ObjectReadRequest::finish(int r) {
CephContext *cct = aio_completion->ictx->cct;
ldout(cct, 10) << "C_ObjectReadRequest: r=" << r
<< dendl;
if (r == -ENOENT) {
r = 0;
}
if (r >= 0) {
ldout(cct, 10) << " got " << extent_map
<< " for " << buffer_extents
<< " bl " << bl.length() << dendl;
// handle the case where a sparse-read wasn't issued
if (extent_map.empty()) {
extent_map[object_off] = bl.length();
}
aio_completion->lock.Lock();
aio_completion->read_result.m_destriper.add_partial_sparse_result(
cct, bl, extent_map, object_off, buffer_extents);
aio_completion->lock.Unlock();
r = object_len;
}
aio_completion->complete_request(r);
}
ReadResult::ReadResult() : m_buffer(Empty()) {
}
ReadResult::ReadResult(char *buf, size_t buf_len)
: m_buffer(Linear(buf, buf_len)) {
}
ReadResult::ReadResult(const struct iovec *iov, int iov_count)
: m_buffer(Vector(iov, iov_count)) {
}
ReadResult::ReadResult(ceph::bufferlist *bl)
: m_buffer(Bufferlist(bl)) {
}
void ReadResult::set_clip_length(size_t length) {
boost::apply_visitor(SetClipLengthVisitor(length), m_buffer);
}
void ReadResult::assemble_result(CephContext *cct) {
boost::apply_visitor(AssembleResultVisitor(cct, m_destriper), m_buffer);
}
} // namespace io
} // namespace librbd
|
