1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4  * Copyright (c) 2013 Red Hat, Inc.
5  * All Rights Reserved.
6  */
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_quota.h"
16 #include "xfs_trans.h"
17 #include "xfs_qm.h"
18 #include "xfs_error.h"
19 #include "xfs_cksum.h"
20 #include "xfs_trace.h"
21 
22 int
xfs_calc_dquots_per_chunk(unsigned int nbblks)23 xfs_calc_dquots_per_chunk(
24 	unsigned int		nbblks)	/* basic block units */
25 {
26 	ASSERT(nbblks > 0);
27 	return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
28 }
29 
30 /*
31  * Do some primitive error checking on ondisk dquot data structures.
32  *
33  * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
34  * we verify them separately because at some points we have only the
35  * smaller xfs_disk_dquot structure available.
36  */
37 
38 xfs_failaddr_t
xfs_dquot_verify(struct xfs_mount * mp,xfs_disk_dquot_t * ddq,xfs_dqid_t id,uint type)39 xfs_dquot_verify(
40 	struct xfs_mount *mp,
41 	xfs_disk_dquot_t *ddq,
42 	xfs_dqid_t	 id,
43 	uint		 type)	  /* used only during quotacheck */
44 {
45 	/*
46 	 * We can encounter an uninitialized dquot buffer for 2 reasons:
47 	 * 1. If we crash while deleting the quotainode(s), and those blks got
48 	 *    used for user data. This is because we take the path of regular
49 	 *    file deletion; however, the size field of quotainodes is never
50 	 *    updated, so all the tricks that we play in itruncate_finish
51 	 *    don't quite matter.
52 	 *
53 	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
54 	 *    But the allocation will be replayed so we'll end up with an
55 	 *    uninitialized quota block.
56 	 *
57 	 * This is all fine; things are still consistent, and we haven't lost
58 	 * any quota information. Just don't complain about bad dquot blks.
59 	 */
60 	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
61 		return __this_address;
62 	if (ddq->d_version != XFS_DQUOT_VERSION)
63 		return __this_address;
64 
65 	if (type && ddq->d_flags != type)
66 		return __this_address;
67 	if (ddq->d_flags != XFS_DQ_USER &&
68 	    ddq->d_flags != XFS_DQ_PROJ &&
69 	    ddq->d_flags != XFS_DQ_GROUP)
70 		return __this_address;
71 
72 	if (id != -1 && id != be32_to_cpu(ddq->d_id))
73 		return __this_address;
74 
75 	if (!ddq->d_id)
76 		return NULL;
77 
78 	if (ddq->d_blk_softlimit &&
79 	    be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
80 	    !ddq->d_btimer)
81 		return __this_address;
82 
83 	if (ddq->d_ino_softlimit &&
84 	    be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
85 	    !ddq->d_itimer)
86 		return __this_address;
87 
88 	if (ddq->d_rtb_softlimit &&
89 	    be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
90 	    !ddq->d_rtbtimer)
91 		return __this_address;
92 
93 	return NULL;
94 }
95 
96 xfs_failaddr_t
xfs_dqblk_verify(struct xfs_mount * mp,struct xfs_dqblk * dqb,xfs_dqid_t id,uint type)97 xfs_dqblk_verify(
98 	struct xfs_mount	*mp,
99 	struct xfs_dqblk	*dqb,
100 	xfs_dqid_t	 	id,
101 	uint		 	type)	/* used only during quotacheck */
102 {
103 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
104 	    !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
105 		return __this_address;
106 
107 	return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
108 }
109 
110 /*
111  * Do some primitive error checking on ondisk dquot data structures.
112  */
113 int
xfs_dqblk_repair(struct xfs_mount * mp,struct xfs_dqblk * dqb,xfs_dqid_t id,uint type)114 xfs_dqblk_repair(
115 	struct xfs_mount	*mp,
116 	struct xfs_dqblk	*dqb,
117 	xfs_dqid_t		id,
118 	uint			type)
119 {
120 	/*
121 	 * Typically, a repair is only requested by quotacheck.
122 	 */
123 	ASSERT(id != -1);
124 	memset(dqb, 0, sizeof(xfs_dqblk_t));
125 
126 	dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
127 	dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
128 	dqb->dd_diskdq.d_flags = type;
129 	dqb->dd_diskdq.d_id = cpu_to_be32(id);
130 
131 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
132 		uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
133 		xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
134 				 XFS_DQUOT_CRC_OFF);
135 	}
136 
137 	return 0;
138 }
139 
140 STATIC bool
xfs_dquot_buf_verify_crc(struct xfs_mount * mp,struct xfs_buf * bp,bool readahead)141 xfs_dquot_buf_verify_crc(
142 	struct xfs_mount	*mp,
143 	struct xfs_buf		*bp,
144 	bool			readahead)
145 {
146 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
147 	int			ndquots;
148 	int			i;
149 
150 	if (!xfs_sb_version_hascrc(&mp->m_sb))
151 		return true;
152 
153 	/*
154 	 * if we are in log recovery, the quota subsystem has not been
155 	 * initialised so we have no quotainfo structure. In that case, we need
156 	 * to manually calculate the number of dquots in the buffer.
157 	 */
158 	if (mp->m_quotainfo)
159 		ndquots = mp->m_quotainfo->qi_dqperchunk;
160 	else
161 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
162 
163 	for (i = 0; i < ndquots; i++, d++) {
164 		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
165 				 XFS_DQUOT_CRC_OFF)) {
166 			if (!readahead)
167 				xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
168 					d, sizeof(*d), __this_address);
169 			return false;
170 		}
171 	}
172 	return true;
173 }
174 
175 STATIC xfs_failaddr_t
xfs_dquot_buf_verify(struct xfs_mount * mp,struct xfs_buf * bp,bool readahead)176 xfs_dquot_buf_verify(
177 	struct xfs_mount	*mp,
178 	struct xfs_buf		*bp,
179 	bool			readahead)
180 {
181 	struct xfs_dqblk	*dqb = bp->b_addr;
182 	xfs_failaddr_t		fa;
183 	xfs_dqid_t		id = 0;
184 	int			ndquots;
185 	int			i;
186 
187 	/*
188 	 * if we are in log recovery, the quota subsystem has not been
189 	 * initialised so we have no quotainfo structure. In that case, we need
190 	 * to manually calculate the number of dquots in the buffer.
191 	 */
192 	if (mp->m_quotainfo)
193 		ndquots = mp->m_quotainfo->qi_dqperchunk;
194 	else
195 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
196 
197 	/*
198 	 * On the first read of the buffer, verify that each dquot is valid.
199 	 * We don't know what the id of the dquot is supposed to be, just that
200 	 * they should be increasing monotonically within the buffer. If the
201 	 * first id is corrupt, then it will fail on the second dquot in the
202 	 * buffer so corruptions could point to the wrong dquot in this case.
203 	 */
204 	for (i = 0; i < ndquots; i++) {
205 		struct xfs_disk_dquot	*ddq;
206 
207 		ddq = &dqb[i].dd_diskdq;
208 
209 		if (i == 0)
210 			id = be32_to_cpu(ddq->d_id);
211 
212 		fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
213 		if (fa) {
214 			if (!readahead)
215 				xfs_buf_verifier_error(bp, -EFSCORRUPTED,
216 					__func__, &dqb[i],
217 					sizeof(struct xfs_dqblk), fa);
218 			return fa;
219 		}
220 	}
221 
222 	return NULL;
223 }
224 
225 static xfs_failaddr_t
xfs_dquot_buf_verify_struct(struct xfs_buf * bp)226 xfs_dquot_buf_verify_struct(
227 	struct xfs_buf		*bp)
228 {
229 	struct xfs_mount	*mp = bp->b_target->bt_mount;
230 
231 	return xfs_dquot_buf_verify(mp, bp, false);
232 }
233 
234 static void
xfs_dquot_buf_read_verify(struct xfs_buf * bp)235 xfs_dquot_buf_read_verify(
236 	struct xfs_buf		*bp)
237 {
238 	struct xfs_mount	*mp = bp->b_target->bt_mount;
239 
240 	if (!xfs_dquot_buf_verify_crc(mp, bp, false))
241 		return;
242 	xfs_dquot_buf_verify(mp, bp, false);
243 }
244 
245 /*
246  * readahead errors are silent and simply leave the buffer as !done so a real
247  * read will then be run with the xfs_dquot_buf_ops verifier. See
248  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
249  * reporting the failure.
250  */
251 static void
xfs_dquot_buf_readahead_verify(struct xfs_buf * bp)252 xfs_dquot_buf_readahead_verify(
253 	struct xfs_buf	*bp)
254 {
255 	struct xfs_mount	*mp = bp->b_target->bt_mount;
256 
257 	if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
258 	    xfs_dquot_buf_verify(mp, bp, true) != NULL) {
259 		xfs_buf_ioerror(bp, -EIO);
260 		bp->b_flags &= ~XBF_DONE;
261 	}
262 }
263 
264 /*
265  * we don't calculate the CRC here as that is done when the dquot is flushed to
266  * the buffer after the update is done. This ensures that the dquot in the
267  * buffer always has an up-to-date CRC value.
268  */
269 static void
xfs_dquot_buf_write_verify(struct xfs_buf * bp)270 xfs_dquot_buf_write_verify(
271 	struct xfs_buf		*bp)
272 {
273 	struct xfs_mount	*mp = bp->b_target->bt_mount;
274 
275 	xfs_dquot_buf_verify(mp, bp, false);
276 }
277 
278 const struct xfs_buf_ops xfs_dquot_buf_ops = {
279 	.name = "xfs_dquot",
280 	.verify_read = xfs_dquot_buf_read_verify,
281 	.verify_write = xfs_dquot_buf_write_verify,
282 	.verify_struct = xfs_dquot_buf_verify_struct,
283 };
284 
285 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
286 	.name = "xfs_dquot_ra",
287 	.verify_read = xfs_dquot_buf_readahead_verify,
288 	.verify_write = xfs_dquot_buf_write_verify,
289 };
290