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
237
238
239
240
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2006 Silicon Graphics, Inc.
* Copyright (c) 2012-2013 Red Hat, Inc.
* All rights reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_shared.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_symlink.h"
#include "xfs_cksum.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_log.h"
/*
* Each contiguous block has a header, so it is not just a simple pathlen
* to FSB conversion.
*/
int
xfs_symlink_blocks(
struct xfs_mount *mp,
int pathlen)
{
int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
return (pathlen + buflen - 1) / buflen;
}
int
xfs_symlink_hdr_set(
struct xfs_mount *mp,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return 0;
memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
dsl->sl_offset = cpu_to_be32(offset);
dsl->sl_bytes = cpu_to_be32(size);
uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
dsl->sl_owner = cpu_to_be64(ino);
dsl->sl_blkno = cpu_to_be64(bp->b_bn);
bp->b_ops = &xfs_symlink_buf_ops;
return sizeof(struct xfs_dsymlink_hdr);
}
/*
* Checking of the symlink header is split into two parts. the verifier does
* CRC, location and bounds checking, the unpacking function checks the path
* parameters and owner.
*/
bool
xfs_symlink_hdr_ok(
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
struct xfs_buf *bp)
{
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (offset != be32_to_cpu(dsl->sl_offset))
return false;
if (size != be32_to_cpu(dsl->sl_bytes))
return false;
if (ino != be64_to_cpu(dsl->sl_owner))
return false;
/* ok */
return true;
}
static xfs_failaddr_t
xfs_symlink_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
if (!xfs_sb_version_hascrc(&mp->m_sb))
return __this_address;
if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
return __this_address;
if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
return __this_address;
if (be32_to_cpu(dsl->sl_offset) +
be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
return __this_address;
if (dsl->sl_owner == 0)
return __this_address;
if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
return __this_address;
return NULL;
}
static void
xfs_symlink_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
xfs_failaddr_t fa;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
xfs_verifier_error(bp, -EFSBADCRC, __this_address);
else {
fa = xfs_symlink_verify(bp);
if (fa)
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
}
}
static void
xfs_symlink_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_buf_log_item *bip = bp->b_log_item;
xfs_failaddr_t fa;
/* no verification of non-crc buffers */
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
fa = xfs_symlink_verify(bp);
if (fa) {
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
}
if (bip) {
struct xfs_dsymlink_hdr *dsl = bp->b_addr;
dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
}
xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
}
const struct xfs_buf_ops xfs_symlink_buf_ops = {
.name = "xfs_symlink",
.verify_read = xfs_symlink_read_verify,
.verify_write = xfs_symlink_write_verify,
.verify_struct = xfs_symlink_verify,
};
void
xfs_symlink_local_to_remote(
struct xfs_trans *tp,
struct xfs_buf *bp,
struct xfs_inode *ip,
struct xfs_ifork *ifp)
{
struct xfs_mount *mp = ip->i_mount;
char *buf;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
if (!xfs_sb_version_hascrc(&mp->m_sb)) {
bp->b_ops = NULL;
memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
return;
}
/*
* As this symlink fits in an inode literal area, it must also fit in
* the smallest buffer the filesystem supports.
*/
ASSERT(BBTOB(bp->b_length) >=
ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
bp->b_ops = &xfs_symlink_buf_ops;
buf = bp->b_addr;
buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
ifp->if_bytes - 1);
}
/*
* Verify the in-memory consistency of an inline symlink data fork. This
* does not do on-disk format checks.
*/
xfs_failaddr_t
xfs_symlink_shortform_verify(
struct xfs_inode *ip)
{
char *sfp;
char *endp;
struct xfs_ifork *ifp;
int size;
ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
sfp = (char *)ifp->if_u1.if_data;
size = ifp->if_bytes;
endp = sfp + size;
/*
* Zero length symlinks should never occur in memory as they are
* never alllowed to exist on disk.
*/
if (!size)
return __this_address;
/* No negative sizes or overly long symlink targets. */
if (size < 0 || size > XFS_SYMLINK_MAXLEN)
return __this_address;
/* No NULLs in the target either. */
if (memchr(sfp, 0, size - 1))
return __this_address;
/* We /did/ null-terminate the buffer, right? */
if (*endp != 0)
return __this_address;
return NULL;
}
|
