mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / xfs / libxfs / xfs_symlink_remote.c
blobc484877129a0d0b55c6f94517c0a1ac1703550fc
1 /*
2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * Copyright (c) 2012-2013 Red Hat, Inc.
4 * All rights reserved.
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
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_shared.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_mount.h"
26 #include "xfs_bmap_btree.h"
27 #include "xfs_inode.h"
28 #include "xfs_error.h"
29 #include "xfs_trace.h"
30 #include "xfs_symlink.h"
31 #include "xfs_cksum.h"
32 #include "xfs_trans.h"
33 #include "xfs_buf_item.h"
34 #include "xfs_log.h"
38 * Each contiguous block has a header, so it is not just a simple pathlen
39 * to FSB conversion.
41 int
42 xfs_symlink_blocks(
43 struct xfs_mount *mp,
44 int pathlen)
46 int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
48 return (pathlen + buflen - 1) / buflen;
51 int
52 xfs_symlink_hdr_set(
53 struct xfs_mount *mp,
54 xfs_ino_t ino,
55 uint32_t offset,
56 uint32_t size,
57 struct xfs_buf *bp)
59 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
61 if (!xfs_sb_version_hascrc(&mp->m_sb))
62 return 0;
64 memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
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_meta_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.
81 bool
82 xfs_symlink_hdr_ok(
83 xfs_ino_t ino,
84 uint32_t offset,
85 uint32_t size,
86 struct xfs_buf *bp)
88 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
90 if (offset != be32_to_cpu(dsl->sl_offset))
91 return false;
92 if (size != be32_to_cpu(dsl->sl_bytes))
93 return false;
94 if (ino != be64_to_cpu(dsl->sl_owner))
95 return false;
97 /* ok */
98 return true;
101 static bool
102 xfs_symlink_verify(
103 struct xfs_buf *bp)
105 struct xfs_mount *mp = bp->b_target->bt_mount;
106 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
108 if (!xfs_sb_version_hascrc(&mp->m_sb))
109 return false;
110 if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
111 return false;
112 if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
113 return false;
114 if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
115 return false;
116 if (be32_to_cpu(dsl->sl_offset) +
117 be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
118 return false;
119 if (dsl->sl_owner == 0)
120 return false;
121 if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
122 return false;
124 return true;
127 static void
128 xfs_symlink_read_verify(
129 struct xfs_buf *bp)
131 struct xfs_mount *mp = bp->b_target->bt_mount;
133 /* no verification of non-crc buffers */
134 if (!xfs_sb_version_hascrc(&mp->m_sb))
135 return;
137 if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
138 xfs_buf_ioerror(bp, -EFSBADCRC);
139 else if (!xfs_symlink_verify(bp))
140 xfs_buf_ioerror(bp, -EFSCORRUPTED);
142 if (bp->b_error)
143 xfs_verifier_error(bp);
146 static void
147 xfs_symlink_write_verify(
148 struct xfs_buf *bp)
150 struct xfs_mount *mp = bp->b_target->bt_mount;
151 struct xfs_buf_log_item *bip = bp->b_fspriv;
153 /* no verification of non-crc buffers */
154 if (!xfs_sb_version_hascrc(&mp->m_sb))
155 return;
157 if (!xfs_symlink_verify(bp)) {
158 xfs_buf_ioerror(bp, -EFSCORRUPTED);
159 xfs_verifier_error(bp);
160 return;
163 if (bip) {
164 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
165 dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
167 xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
170 const struct xfs_buf_ops xfs_symlink_buf_ops = {
171 .name = "xfs_symlink",
172 .verify_read = xfs_symlink_read_verify,
173 .verify_write = xfs_symlink_write_verify,
176 void
177 xfs_symlink_local_to_remote(
178 struct xfs_trans *tp,
179 struct xfs_buf *bp,
180 struct xfs_inode *ip,
181 struct xfs_ifork *ifp)
183 struct xfs_mount *mp = ip->i_mount;
184 char *buf;
186 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
188 if (!xfs_sb_version_hascrc(&mp->m_sb)) {
189 bp->b_ops = NULL;
190 memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
191 xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
192 return;
196 * As this symlink fits in an inode literal area, it must also fit in
197 * the smallest buffer the filesystem supports.
199 ASSERT(BBTOB(bp->b_length) >=
200 ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
202 bp->b_ops = &xfs_symlink_buf_ops;
204 buf = bp->b_addr;
205 buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
206 memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
207 xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
208 ifp->if_bytes - 1);