xref: /openbmc/linux/fs/xfs/libxfs/xfs_dquot_buf.c (revision e3b9f1e8)
1 /*
2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3  * Copyright (c) 2013 Red Hat, Inc.
4  * All Rights Reserved.
5  *
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.
9  *
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.
14  *
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
18  */
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_shared.h"
22 #include "xfs_format.h"
23 #include "xfs_log_format.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_mount.h"
26 #include "xfs_inode.h"
27 #include "xfs_quota.h"
28 #include "xfs_trans.h"
29 #include "xfs_qm.h"
30 #include "xfs_error.h"
31 #include "xfs_cksum.h"
32 #include "xfs_trace.h"
33 
34 int
35 xfs_calc_dquots_per_chunk(
36 	unsigned int		nbblks)	/* basic block units */
37 {
38 	ASSERT(nbblks > 0);
39 	return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
40 }
41 
42 /*
43  * Do some primitive error checking on ondisk dquot data structures.
44  */
45 xfs_failaddr_t
46 xfs_dquot_verify(
47 	struct xfs_mount *mp,
48 	xfs_disk_dquot_t *ddq,
49 	xfs_dqid_t	 id,
50 	uint		 type,	  /* used only when IO_dorepair is true */
51 	uint		 flags)
52 {
53 	/*
54 	 * We can encounter an uninitialized dquot buffer for 2 reasons:
55 	 * 1. If we crash while deleting the quotainode(s), and those blks got
56 	 *    used for user data. This is because we take the path of regular
57 	 *    file deletion; however, the size field of quotainodes is never
58 	 *    updated, so all the tricks that we play in itruncate_finish
59 	 *    don't quite matter.
60 	 *
61 	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
62 	 *    But the allocation will be replayed so we'll end up with an
63 	 *    uninitialized quota block.
64 	 *
65 	 * This is all fine; things are still consistent, and we haven't lost
66 	 * any quota information. Just don't complain about bad dquot blks.
67 	 */
68 	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
69 		return __this_address;
70 	if (ddq->d_version != XFS_DQUOT_VERSION)
71 		return __this_address;
72 
73 	if (ddq->d_flags != XFS_DQ_USER &&
74 	    ddq->d_flags != XFS_DQ_PROJ &&
75 	    ddq->d_flags != XFS_DQ_GROUP)
76 		return __this_address;
77 
78 	if (id != -1 && id != be32_to_cpu(ddq->d_id))
79 		return __this_address;
80 
81 	if (!ddq->d_id)
82 		return NULL;
83 
84 	if (ddq->d_blk_softlimit &&
85 	    be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
86 	    !ddq->d_btimer)
87 		return __this_address;
88 
89 	if (ddq->d_ino_softlimit &&
90 	    be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
91 	    !ddq->d_itimer)
92 		return __this_address;
93 
94 	if (ddq->d_rtb_softlimit &&
95 	    be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
96 	    !ddq->d_rtbtimer)
97 		return __this_address;
98 
99 	return NULL;
100 }
101 
102 /*
103  * Do some primitive error checking on ondisk dquot data structures.
104  */
105 int
106 xfs_dquot_repair(
107 	struct xfs_mount	*mp,
108 	struct xfs_disk_dquot	*ddq,
109 	xfs_dqid_t		id,
110 	uint			type)
111 {
112 	struct xfs_dqblk	*d = (struct xfs_dqblk *)ddq;
113 
114 
115 	/*
116 	 * Typically, a repair is only requested by quotacheck.
117 	 */
118 	ASSERT(id != -1);
119 	memset(d, 0, sizeof(xfs_dqblk_t));
120 
121 	d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
122 	d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
123 	d->dd_diskdq.d_flags = type;
124 	d->dd_diskdq.d_id = cpu_to_be32(id);
125 
126 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
127 		uuid_copy(&d->dd_uuid, &mp->m_sb.sb_meta_uuid);
128 		xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
129 				 XFS_DQUOT_CRC_OFF);
130 	}
131 
132 	return 0;
133 }
134 
135 STATIC bool
136 xfs_dquot_buf_verify_crc(
137 	struct xfs_mount	*mp,
138 	struct xfs_buf		*bp)
139 {
140 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
141 	int			ndquots;
142 	int			i;
143 
144 	if (!xfs_sb_version_hascrc(&mp->m_sb))
145 		return true;
146 
147 	/*
148 	 * if we are in log recovery, the quota subsystem has not been
149 	 * initialised so we have no quotainfo structure. In that case, we need
150 	 * to manually calculate the number of dquots in the buffer.
151 	 */
152 	if (mp->m_quotainfo)
153 		ndquots = mp->m_quotainfo->qi_dqperchunk;
154 	else
155 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
156 
157 	for (i = 0; i < ndquots; i++, d++) {
158 		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
159 				 XFS_DQUOT_CRC_OFF))
160 			return false;
161 		if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_meta_uuid))
162 			return false;
163 	}
164 	return true;
165 }
166 
167 STATIC xfs_failaddr_t
168 xfs_dquot_buf_verify(
169 	struct xfs_mount	*mp,
170 	struct xfs_buf		*bp)
171 {
172 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
173 	xfs_failaddr_t		fa;
174 	xfs_dqid_t		id = 0;
175 	int			ndquots;
176 	int			i;
177 
178 	/*
179 	 * if we are in log recovery, the quota subsystem has not been
180 	 * initialised so we have no quotainfo structure. In that case, we need
181 	 * to manually calculate the number of dquots in the buffer.
182 	 */
183 	if (mp->m_quotainfo)
184 		ndquots = mp->m_quotainfo->qi_dqperchunk;
185 	else
186 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
187 
188 	/*
189 	 * On the first read of the buffer, verify that each dquot is valid.
190 	 * We don't know what the id of the dquot is supposed to be, just that
191 	 * they should be increasing monotonically within the buffer. If the
192 	 * first id is corrupt, then it will fail on the second dquot in the
193 	 * buffer so corruptions could point to the wrong dquot in this case.
194 	 */
195 	for (i = 0; i < ndquots; i++) {
196 		struct xfs_disk_dquot	*ddq;
197 
198 		ddq = &d[i].dd_diskdq;
199 
200 		if (i == 0)
201 			id = be32_to_cpu(ddq->d_id);
202 
203 		fa = xfs_dquot_verify(mp, ddq, id + i, 0, 0);
204 		if (fa)
205 			return fa;
206 	}
207 
208 	return NULL;
209 }
210 
211 static xfs_failaddr_t
212 xfs_dquot_buf_verify_struct(
213 	struct xfs_buf		*bp)
214 {
215 	struct xfs_mount	*mp = bp->b_target->bt_mount;
216 
217 	return xfs_dquot_buf_verify(mp, bp);
218 }
219 
220 static void
221 xfs_dquot_buf_read_verify(
222 	struct xfs_buf		*bp)
223 {
224 	struct xfs_mount	*mp = bp->b_target->bt_mount;
225 	xfs_failaddr_t		fa;
226 
227 	if (!xfs_dquot_buf_verify_crc(mp, bp))
228 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
229 	else {
230 		fa = xfs_dquot_buf_verify(mp, bp);
231 		if (fa)
232 			xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
233 	}
234 }
235 
236 /*
237  * readahead errors are silent and simply leave the buffer as !done so a real
238  * read will then be run with the xfs_dquot_buf_ops verifier. See
239  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
240  * reporting the failure.
241  */
242 static void
243 xfs_dquot_buf_readahead_verify(
244 	struct xfs_buf	*bp)
245 {
246 	struct xfs_mount	*mp = bp->b_target->bt_mount;
247 
248 	if (!xfs_dquot_buf_verify_crc(mp, bp) ||
249 	    xfs_dquot_buf_verify(mp, bp) != NULL) {
250 		xfs_buf_ioerror(bp, -EIO);
251 		bp->b_flags &= ~XBF_DONE;
252 	}
253 }
254 
255 /*
256  * we don't calculate the CRC here as that is done when the dquot is flushed to
257  * the buffer after the update is done. This ensures that the dquot in the
258  * buffer always has an up-to-date CRC value.
259  */
260 static void
261 xfs_dquot_buf_write_verify(
262 	struct xfs_buf		*bp)
263 {
264 	struct xfs_mount	*mp = bp->b_target->bt_mount;
265 	xfs_failaddr_t		fa;
266 
267 	fa = xfs_dquot_buf_verify(mp, bp);
268 	if (fa)
269 		xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
270 }
271 
272 const struct xfs_buf_ops xfs_dquot_buf_ops = {
273 	.name = "xfs_dquot",
274 	.verify_read = xfs_dquot_buf_read_verify,
275 	.verify_write = xfs_dquot_buf_write_verify,
276 	.verify_struct = xfs_dquot_buf_verify_struct,
277 };
278 
279 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
280 	.name = "xfs_dquot_ra",
281 	.verify_read = xfs_dquot_buf_readahead_verify,
282 	.verify_write = xfs_dquot_buf_write_verify,
283 };
284