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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/*-
* Copyright (c) 2014-present MongoDB, Inc.
* Copyright (c) 2008-2014 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
/*
* __wt_bm_read --
* Map or read address cookie referenced block into a buffer.
*/
int
__wt_bm_read(
WT_BM *bm, WT_SESSION_IMPL *session, WT_ITEM *buf, const uint8_t *addr, size_t addr_size)
{
WT_BLOCK *block;
wt_off_t offset;
uint32_t checksum, objectid, size;
block = bm->block;
/* Crack the cookie. */
WT_RET(__wt_block_addr_unpack(
session, block, addr, addr_size, &objectid, &offset, &size, &checksum));
#ifdef HAVE_DIAGNOSTIC
/*
* In diagnostic mode, verify the block we're about to read isn't on the available list, or for
* live systems, the discard list. This only applies if the block is in this object.
*/
if (objectid == block->objectid)
WT_RET(__wt_block_misplaced(
session, block, "read", offset, size, bm->is_live, __PRETTY_FUNCTION__, __LINE__));
#endif
/* Read the block. */
__wt_capacity_throttle(session, size, WT_THROTTLE_READ);
WT_RET(__wt_block_read_off(session, block, buf, objectid, offset, size, checksum));
/* Optionally discard blocks from the system's buffer cache. */
WT_RET(__wt_block_discard(session, block, (size_t)size));
return (0);
}
/*
* __wt_bm_corrupt_dump --
* Dump a block into the log in 1KB chunks.
*/
static int
__wt_bm_corrupt_dump(WT_SESSION_IMPL *session, WT_ITEM *buf, uint32_t objectid, wt_off_t offset,
uint32_t size, uint32_t checksum) WT_GCC_FUNC_ATTRIBUTE((cold))
{
WT_DECL_ITEM(tmp);
WT_DECL_RET;
size_t chunk, i, nchunks;
#define WT_CORRUPT_FMT "{%" PRIu32 ": %" PRIuMAX ", %" PRIu32 ", %#" PRIx32 "}"
if (buf->size == 0) {
__wt_errx(session, WT_CORRUPT_FMT ": empty buffer, no dump available", objectid,
(uintmax_t)offset, size, checksum);
return (0);
}
WT_RET(__wt_scr_alloc(session, 4 * 1024, &tmp));
nchunks = buf->size / 1024 + (buf->size % 1024 == 0 ? 0 : 1);
for (chunk = i = 0;;) {
WT_ERR(__wt_buf_catfmt(session, tmp, "%02x ", ((uint8_t *)buf->data)[i]));
if (++i == buf->size || i % 1024 == 0) {
__wt_errx(session,
WT_CORRUPT_FMT ": (chunk %" WT_SIZET_FMT " of %" WT_SIZET_FMT "): %.*s", objectid,
(uintmax_t)offset, size, checksum, ++chunk, nchunks, (int)tmp->size,
(char *)tmp->data);
if (i == buf->size)
break;
WT_ERR(__wt_buf_set(session, tmp, "", 0));
}
}
err:
__wt_scr_free(session, &tmp);
return (ret);
}
/*
* __wt_bm_corrupt --
* Report a block has been corrupted, external API.
*/
int
__wt_bm_corrupt(WT_BM *bm, WT_SESSION_IMPL *session, const uint8_t *addr, size_t addr_size)
{
WT_DECL_ITEM(tmp);
WT_DECL_RET;
wt_off_t offset;
uint32_t checksum, objectid, size;
/* Read the block. */
WT_RET(__wt_scr_alloc(session, 0, &tmp));
WT_ERR(__wt_bm_read(bm, session, tmp, addr, addr_size));
/* Crack the cookie, dump the block. */
WT_ERR(__wt_block_addr_unpack(
session, bm->block, addr, addr_size, &objectid, &offset, &size, &checksum));
WT_ERR(__wt_bm_corrupt_dump(session, tmp, objectid, offset, size, checksum));
err:
__wt_scr_free(session, &tmp);
return (ret);
}
#ifdef HAVE_DIAGNOSTIC
/*
* __wt_block_read_off_blind --
* Read the block at an offset, return the size and checksum, debugging only.
*/
int
__wt_block_read_off_blind(
WT_SESSION_IMPL *session, WT_BLOCK *block, wt_off_t offset, uint32_t *sizep, uint32_t *checksump)
{
WT_BLOCK_HEADER *blk;
WT_DECL_ITEM(tmp);
WT_DECL_RET;
*sizep = 0;
*checksump = 0;
/*
* Make sure the buffer is large enough for the header and read the first allocation-size block.
*/
WT_RET(__wt_scr_alloc(session, block->allocsize, &tmp));
WT_ERR(__wt_read(session, block->fh, offset, (size_t)block->allocsize, tmp->mem));
blk = WT_BLOCK_HEADER_REF(tmp->mem);
__wt_block_header_byteswap(blk);
*sizep = blk->disk_size;
*checksump = blk->checksum;
err:
__wt_scr_free(session, &tmp);
return (ret);
}
#endif
/*
* __wt_block_read_off --
* Read an addr/size pair referenced block into a buffer.
*/
int
__wt_block_read_off(WT_SESSION_IMPL *session, WT_BLOCK *block, WT_ITEM *buf, uint32_t objectid,
wt_off_t offset, uint32_t size, uint32_t checksum)
{
WT_BLOCK_HEADER *blk, swap;
size_t bufsize;
__wt_verbose(session, WT_VERB_READ, "off %" PRIuMAX ", size %" PRIu32 ", checksum %#" PRIx32,
(uintmax_t)offset, size, checksum);
WT_STAT_CONN_INCR(session, block_read);
WT_STAT_CONN_INCRV(session, block_byte_read, size);
/* Swap file handles if reading from a different object. */
if (block->objectid != objectid)
WT_RET(__wt_blkcache_get_handle(session, block, objectid, &block));
/*
* Grow the buffer as necessary and read the block. Buffers should be aligned for reading, but
* there are lots of buffers (for example, file cursors have two buffers each, key and value),
* and it's difficult to be sure we've found all of them. If the buffer isn't aligned, it's an
* easy fix: set the flag and guarantee we reallocate it. (Most of the time on reads, the buffer
* memory has not yet been allocated, so we're not adding any additional processing time.)
*/
if (F_ISSET(buf, WT_ITEM_ALIGNED))
bufsize = size;
else {
F_SET(buf, WT_ITEM_ALIGNED);
bufsize = WT_MAX(size, buf->memsize + 10);
}
/*
* Ensure we don't read information that isn't there. It shouldn't ever happen, but it's a cheap
* test.
*/
if (size < block->allocsize)
WT_RET_MSG(session, EINVAL,
"%s: impossibly small block size of %" PRIu32 "B, less than allocation size of %" PRIu32,
block->name, size, block->allocsize);
WT_RET(__wt_buf_init(session, buf, bufsize));
buf->size = size;
WT_RET(__wt_read(session, block->fh, offset, size, buf->mem));
/*
* We incrementally read through the structure before doing a checksum, do little- to big-endian
* handling early on, and then select from the original or swapped structure as needed.
*/
blk = WT_BLOCK_HEADER_REF(buf->mem);
__wt_block_header_byteswap_copy(blk, &swap);
if (swap.checksum == checksum) {
blk->checksum = 0;
if (__wt_checksum_match(buf->mem,
F_ISSET(&swap, WT_BLOCK_DATA_CKSUM) ? size : WT_BLOCK_COMPRESS_SKIP, checksum)) {
/*
* Swap the page-header as needed; this doesn't belong here, but it's the best place to
* catch all callers.
*/
__wt_page_header_byteswap(buf->mem);
return (0);
}
if (!F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE))
__wt_errx(session,
"%s: potential hardware corruption, read checksum error for %" PRIu32
"B block at offset %" PRIuMAX
": calculated block checksum doesn't match expected checksum",
block->name, size, (uintmax_t)offset);
} else if (!F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE))
__wt_errx(session,
"%s: potential hardware corruption, read checksum error for %" PRIu32
"B block at offset %" PRIuMAX ": block header checksum of %#" PRIx32
" doesn't match expected checksum of %#" PRIx32,
block->name, size, (uintmax_t)offset, swap.checksum, checksum);
if (!F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE))
WT_IGNORE_RET(__wt_bm_corrupt_dump(session, buf, objectid, offset, size, checksum));
/* Panic if a checksum fails during an ordinary read. */
F_SET(S2C(session), WT_CONN_DATA_CORRUPTION);
if (block->verify || F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE))
return (WT_ERROR);
WT_RET_PANIC(session, WT_ERROR, "%s: fatal read error", block->name);
}
|
