2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * Copyright (c) 2012-2013 Red Hat, Inc.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_shared.h"
24 #include "xfs_trans_resv.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_inode.h"
30 #include "xfs_error.h"
31 #include "xfs_trace.h"
32 #include "xfs_symlink.h"
33 #include "xfs_cksum.h"
34 #include "xfs_trans.h"
35 #include "xfs_buf_item.h"
39 * Each contiguous block has a header, so it is not just a simple pathlen
47 int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
49 return (pathlen + buflen - 1) / buflen;
60 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
62 if (!xfs_sb_version_hascrc(&mp->m_sb))
65 dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
66 dsl->sl_offset = cpu_to_be32(offset);
67 dsl->sl_bytes = cpu_to_be32(size);
68 uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_uuid);
69 dsl->sl_owner = cpu_to_be64(ino);
70 dsl->sl_blkno = cpu_to_be64(bp->b_bn);
71 bp->b_ops = &xfs_symlink_buf_ops;
73 return sizeof(struct xfs_dsymlink_hdr);
77 * Checking of the symlink header is split into two parts. the verifier does
78 * CRC, location and bounds checking, the unpacking function checks the path
79 * parameters and owner.
89 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
91 if (offset != be32_to_cpu(dsl->sl_offset))
93 if (size != be32_to_cpu(dsl->sl_bytes))
95 if (ino != be64_to_cpu(dsl->sl_owner))
106 struct xfs_mount *mp = bp->b_target->bt_mount;
107 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
109 if (!xfs_sb_version_hascrc(&mp->m_sb))
111 if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
113 if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
115 if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
117 if (be32_to_cpu(dsl->sl_offset) +
118 be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
120 if (dsl->sl_owner == 0)
127 xfs_symlink_read_verify(
130 struct xfs_mount *mp = bp->b_target->bt_mount;
132 /* no verification of non-crc buffers */
133 if (!xfs_sb_version_hascrc(&mp->m_sb))
136 if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
137 xfs_buf_ioerror(bp, EFSBADCRC);
138 else if (!xfs_symlink_verify(bp))
139 xfs_buf_ioerror(bp, EFSCORRUPTED);
142 xfs_verifier_error(bp);
146 xfs_symlink_write_verify(
149 struct xfs_mount *mp = bp->b_target->bt_mount;
150 struct xfs_buf_log_item *bip = bp->b_fspriv;
152 /* no verification of non-crc buffers */
153 if (!xfs_sb_version_hascrc(&mp->m_sb))
156 if (!xfs_symlink_verify(bp)) {
157 xfs_buf_ioerror(bp, EFSCORRUPTED);
158 xfs_verifier_error(bp);
163 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
164 dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
166 xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
169 const struct xfs_buf_ops xfs_symlink_buf_ops = {
170 .verify_read = xfs_symlink_read_verify,
171 .verify_write = xfs_symlink_write_verify,
175 xfs_symlink_local_to_remote(
176 struct xfs_trans *tp,
178 struct xfs_inode *ip,
179 struct xfs_ifork *ifp)
181 struct xfs_mount *mp = ip->i_mount;
184 if (!xfs_sb_version_hascrc(&mp->m_sb)) {
186 memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
191 * As this symlink fits in an inode literal area, it must also fit in
192 * the smallest buffer the filesystem supports.
194 ASSERT(BBTOB(bp->b_length) >=
195 ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
197 bp->b_ops = &xfs_symlink_buf_ops;
200 buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
201 memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);