xref: /openbmc/linux/fs/xfs/libxfs/xfs_dquot_buf.c (revision 29c37341)
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 
20 int
21 xfs_calc_dquots_per_chunk(
22 	unsigned int		nbblks)	/* basic block units */
23 {
24 	ASSERT(nbblks > 0);
25 	return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
26 }
27 
28 /*
29  * Do some primitive error checking on ondisk dquot data structures.
30  *
31  * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
32  * we verify them separately because at some points we have only the
33  * smaller xfs_disk_dquot structure available.
34  */
35 
36 xfs_failaddr_t
37 xfs_dquot_verify(
38 	struct xfs_mount	*mp,
39 	struct xfs_disk_dquot	*ddq,
40 	xfs_dqid_t		id)	/* used only during quotacheck */
41 {
42 	__u8			ddq_type;
43 
44 	/*
45 	 * We can encounter an uninitialized dquot buffer for 2 reasons:
46 	 * 1. If we crash while deleting the quotainode(s), and those blks got
47 	 *    used for user data. This is because we take the path of regular
48 	 *    file deletion; however, the size field of quotainodes is never
49 	 *    updated, so all the tricks that we play in itruncate_finish
50 	 *    don't quite matter.
51 	 *
52 	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
53 	 *    But the allocation will be replayed so we'll end up with an
54 	 *    uninitialized quota block.
55 	 *
56 	 * This is all fine; things are still consistent, and we haven't lost
57 	 * any quota information. Just don't complain about bad dquot blks.
58 	 */
59 	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
60 		return __this_address;
61 	if (ddq->d_version != XFS_DQUOT_VERSION)
62 		return __this_address;
63 
64 	if (ddq->d_type & ~XFS_DQTYPE_ANY)
65 		return __this_address;
66 	ddq_type = ddq->d_type & XFS_DQTYPE_REC_MASK;
67 	if (ddq_type != XFS_DQTYPE_USER &&
68 	    ddq_type != XFS_DQTYPE_PROJ &&
69 	    ddq_type != XFS_DQTYPE_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
97 xfs_dqblk_verify(
98 	struct xfs_mount	*mp,
99 	struct xfs_dqblk	*dqb,
100 	xfs_dqid_t		id)	/* used only during quotacheck */
101 {
102 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
103 	    !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
104 		return __this_address;
105 
106 	return xfs_dquot_verify(mp, &dqb->dd_diskdq, id);
107 }
108 
109 /*
110  * Do some primitive error checking on ondisk dquot data structures.
111  */
112 void
113 xfs_dqblk_repair(
114 	struct xfs_mount	*mp,
115 	struct xfs_dqblk	*dqb,
116 	xfs_dqid_t		id,
117 	xfs_dqtype_t		type)
118 {
119 	/*
120 	 * Typically, a repair is only requested by quotacheck.
121 	 */
122 	ASSERT(id != -1);
123 	memset(dqb, 0, sizeof(xfs_dqblk_t));
124 
125 	dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
126 	dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
127 	dqb->dd_diskdq.d_type = type;
128 	dqb->dd_diskdq.d_id = cpu_to_be32(id);
129 
130 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
131 		uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
132 		xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
133 				 XFS_DQUOT_CRC_OFF);
134 	}
135 }
136 
137 STATIC bool
138 xfs_dquot_buf_verify_crc(
139 	struct xfs_mount	*mp,
140 	struct xfs_buf		*bp,
141 	bool			readahead)
142 {
143 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
144 	int			ndquots;
145 	int			i;
146 
147 	if (!xfs_sb_version_hascrc(&mp->m_sb))
148 		return true;
149 
150 	/*
151 	 * if we are in log recovery, the quota subsystem has not been
152 	 * initialised so we have no quotainfo structure. In that case, we need
153 	 * to manually calculate the number of dquots in the buffer.
154 	 */
155 	if (mp->m_quotainfo)
156 		ndquots = mp->m_quotainfo->qi_dqperchunk;
157 	else
158 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
159 
160 	for (i = 0; i < ndquots; i++, d++) {
161 		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
162 				 XFS_DQUOT_CRC_OFF)) {
163 			if (!readahead)
164 				xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
165 					d, sizeof(*d), __this_address);
166 			return false;
167 		}
168 	}
169 	return true;
170 }
171 
172 STATIC xfs_failaddr_t
173 xfs_dquot_buf_verify(
174 	struct xfs_mount	*mp,
175 	struct xfs_buf		*bp,
176 	bool			readahead)
177 {
178 	struct xfs_dqblk	*dqb = bp->b_addr;
179 	xfs_failaddr_t		fa;
180 	xfs_dqid_t		id = 0;
181 	int			ndquots;
182 	int			i;
183 
184 	/*
185 	 * if we are in log recovery, the quota subsystem has not been
186 	 * initialised so we have no quotainfo structure. In that case, we need
187 	 * to manually calculate the number of dquots in the buffer.
188 	 */
189 	if (mp->m_quotainfo)
190 		ndquots = mp->m_quotainfo->qi_dqperchunk;
191 	else
192 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
193 
194 	/*
195 	 * On the first read of the buffer, verify that each dquot is valid.
196 	 * We don't know what the id of the dquot is supposed to be, just that
197 	 * they should be increasing monotonically within the buffer. If the
198 	 * first id is corrupt, then it will fail on the second dquot in the
199 	 * buffer so corruptions could point to the wrong dquot in this case.
200 	 */
201 	for (i = 0; i < ndquots; i++) {
202 		struct xfs_disk_dquot	*ddq;
203 
204 		ddq = &dqb[i].dd_diskdq;
205 
206 		if (i == 0)
207 			id = be32_to_cpu(ddq->d_id);
208 
209 		fa = xfs_dqblk_verify(mp, &dqb[i], id + i);
210 		if (fa) {
211 			if (!readahead)
212 				xfs_buf_verifier_error(bp, -EFSCORRUPTED,
213 					__func__, &dqb[i],
214 					sizeof(struct xfs_dqblk), fa);
215 			return fa;
216 		}
217 	}
218 
219 	return NULL;
220 }
221 
222 static xfs_failaddr_t
223 xfs_dquot_buf_verify_struct(
224 	struct xfs_buf		*bp)
225 {
226 	struct xfs_mount	*mp = bp->b_mount;
227 
228 	return xfs_dquot_buf_verify(mp, bp, false);
229 }
230 
231 static void
232 xfs_dquot_buf_read_verify(
233 	struct xfs_buf		*bp)
234 {
235 	struct xfs_mount	*mp = bp->b_mount;
236 
237 	if (!xfs_dquot_buf_verify_crc(mp, bp, false))
238 		return;
239 	xfs_dquot_buf_verify(mp, bp, false);
240 }
241 
242 /*
243  * readahead errors are silent and simply leave the buffer as !done so a real
244  * read will then be run with the xfs_dquot_buf_ops verifier. See
245  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
246  * reporting the failure.
247  */
248 static void
249 xfs_dquot_buf_readahead_verify(
250 	struct xfs_buf	*bp)
251 {
252 	struct xfs_mount	*mp = bp->b_mount;
253 
254 	if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
255 	    xfs_dquot_buf_verify(mp, bp, true) != NULL) {
256 		xfs_buf_ioerror(bp, -EIO);
257 		bp->b_flags &= ~XBF_DONE;
258 	}
259 }
260 
261 /*
262  * we don't calculate the CRC here as that is done when the dquot is flushed to
263  * the buffer after the update is done. This ensures that the dquot in the
264  * buffer always has an up-to-date CRC value.
265  */
266 static void
267 xfs_dquot_buf_write_verify(
268 	struct xfs_buf		*bp)
269 {
270 	struct xfs_mount	*mp = bp->b_mount;
271 
272 	xfs_dquot_buf_verify(mp, bp, false);
273 }
274 
275 const struct xfs_buf_ops xfs_dquot_buf_ops = {
276 	.name = "xfs_dquot",
277 	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
278 		     cpu_to_be16(XFS_DQUOT_MAGIC) },
279 	.verify_read = xfs_dquot_buf_read_verify,
280 	.verify_write = xfs_dquot_buf_write_verify,
281 	.verify_struct = xfs_dquot_buf_verify_struct,
282 };
283 
284 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
285 	.name = "xfs_dquot_ra",
286 	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
287 		     cpu_to_be16(XFS_DQUOT_MAGIC) },
288 	.verify_read = xfs_dquot_buf_readahead_verify,
289 	.verify_write = xfs_dquot_buf_write_verify,
290 };
291