1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4 * Copyright (c) 2012-2013 Red Hat, Inc.
7 #include "libxfs_priv.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_shared.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_bmap_btree.h"
15 #include "xfs_inode.h"
16 #include "xfs_trace.h"
17 #include "xfs_cksum.h"
18 #include "xfs_trans.h"
22 * Each contiguous block has a header, so it is not just a simple pathlen
30 int buflen
= XFS_SYMLINK_BUF_SPACE(mp
, mp
->m_sb
.sb_blocksize
);
32 return (pathlen
+ buflen
- 1) / buflen
;
43 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
45 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
48 memset(dsl
, 0, sizeof(struct xfs_dsymlink_hdr
));
49 dsl
->sl_magic
= cpu_to_be32(XFS_SYMLINK_MAGIC
);
50 dsl
->sl_offset
= cpu_to_be32(offset
);
51 dsl
->sl_bytes
= cpu_to_be32(size
);
52 uuid_copy(&dsl
->sl_uuid
, &mp
->m_sb
.sb_meta_uuid
);
53 dsl
->sl_owner
= cpu_to_be64(ino
);
54 dsl
->sl_blkno
= cpu_to_be64(bp
->b_bn
);
55 bp
->b_ops
= &xfs_symlink_buf_ops
;
57 return sizeof(struct xfs_dsymlink_hdr
);
61 * Checking of the symlink header is split into two parts. the verifier does
62 * CRC, location and bounds checking, the unpacking function checks the path
63 * parameters and owner.
72 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
74 if (offset
!= be32_to_cpu(dsl
->sl_offset
))
76 if (size
!= be32_to_cpu(dsl
->sl_bytes
))
78 if (ino
!= be64_to_cpu(dsl
->sl_owner
))
89 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
90 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
92 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
93 return __this_address
;
94 if (dsl
->sl_magic
!= cpu_to_be32(XFS_SYMLINK_MAGIC
))
95 return __this_address
;
96 if (!uuid_equal(&dsl
->sl_uuid
, &mp
->m_sb
.sb_meta_uuid
))
97 return __this_address
;
98 if (bp
->b_bn
!= be64_to_cpu(dsl
->sl_blkno
))
99 return __this_address
;
100 if (be32_to_cpu(dsl
->sl_offset
) +
101 be32_to_cpu(dsl
->sl_bytes
) >= XFS_SYMLINK_MAXLEN
)
102 return __this_address
;
103 if (dsl
->sl_owner
== 0)
104 return __this_address
;
105 if (!xfs_log_check_lsn(mp
, be64_to_cpu(dsl
->sl_lsn
)))
106 return __this_address
;
112 xfs_symlink_read_verify(
115 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
118 /* no verification of non-crc buffers */
119 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
122 if (!xfs_buf_verify_cksum(bp
, XFS_SYMLINK_CRC_OFF
))
123 xfs_verifier_error(bp
, -EFSBADCRC
, __this_address
);
125 fa
= xfs_symlink_verify(bp
);
127 xfs_verifier_error(bp
, -EFSCORRUPTED
, fa
);
132 xfs_symlink_write_verify(
135 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
136 struct xfs_buf_log_item
*bip
= bp
->b_log_item
;
139 /* no verification of non-crc buffers */
140 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
143 fa
= xfs_symlink_verify(bp
);
145 xfs_verifier_error(bp
, -EFSCORRUPTED
, fa
);
150 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
151 dsl
->sl_lsn
= cpu_to_be64(bip
->bli_item
.li_lsn
);
153 xfs_buf_update_cksum(bp
, XFS_SYMLINK_CRC_OFF
);
156 const struct xfs_buf_ops xfs_symlink_buf_ops
= {
157 .name
= "xfs_symlink",
158 .verify_read
= xfs_symlink_read_verify
,
159 .verify_write
= xfs_symlink_write_verify
,
160 .verify_struct
= xfs_symlink_verify
,
164 xfs_symlink_local_to_remote(
165 struct xfs_trans
*tp
,
167 struct xfs_inode
*ip
,
168 struct xfs_ifork
*ifp
)
170 struct xfs_mount
*mp
= ip
->i_mount
;
173 xfs_trans_buf_set_type(tp
, bp
, XFS_BLFT_SYMLINK_BUF
);
175 if (!xfs_sb_version_hascrc(&mp
->m_sb
)) {
177 memcpy(bp
->b_addr
, ifp
->if_u1
.if_data
, ifp
->if_bytes
);
178 xfs_trans_log_buf(tp
, bp
, 0, ifp
->if_bytes
- 1);
183 * As this symlink fits in an inode literal area, it must also fit in
184 * the smallest buffer the filesystem supports.
186 ASSERT(BBTOB(bp
->b_length
) >=
187 ifp
->if_bytes
+ sizeof(struct xfs_dsymlink_hdr
));
189 bp
->b_ops
= &xfs_symlink_buf_ops
;
192 buf
+= xfs_symlink_hdr_set(mp
, ip
->i_ino
, 0, ifp
->if_bytes
, bp
);
193 memcpy(buf
, ifp
->if_u1
.if_data
, ifp
->if_bytes
);
194 xfs_trans_log_buf(tp
, bp
, 0, sizeof(struct xfs_dsymlink_hdr
) +
198 /* Verify the consistency of an inline symlink. */
200 xfs_symlink_shortform_verify(
201 struct xfs_inode
*ip
)
205 struct xfs_ifork
*ifp
;
208 ASSERT(ip
->i_d
.di_format
== XFS_DINODE_FMT_LOCAL
);
209 ifp
= XFS_IFORK_PTR(ip
, XFS_DATA_FORK
);
210 sfp
= (char *)ifp
->if_u1
.if_data
;
211 size
= ifp
->if_bytes
;
214 /* Zero length symlinks can exist while we're deleting a remote one. */
218 /* No negative sizes or overly long symlink targets. */
219 if (size
< 0 || size
> XFS_SYMLINK_MAXLEN
)
220 return __this_address
;
222 /* No NULLs in the target either. */
223 if (memchr(sfp
, 0, size
- 1))
224 return __this_address
;
226 /* We /did/ null-terminate the buffer, right? */
228 return __this_address
;