xref: /openbmc/linux/fs/xfs/libxfs/xfs_dquot_buf.c (revision 20e2fc42)
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 	xfs_disk_dquot_t *ddq,
40 	xfs_dqid_t	 id,
41 	uint		 type)	  /* used only during quotacheck */
42 {
43 	/*
44 	 * We can encounter an uninitialized dquot buffer for 2 reasons:
45 	 * 1. If we crash while deleting the quotainode(s), and those blks got
46 	 *    used for user data. This is because we take the path of regular
47 	 *    file deletion; however, the size field of quotainodes is never
48 	 *    updated, so all the tricks that we play in itruncate_finish
49 	 *    don't quite matter.
50 	 *
51 	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
52 	 *    But the allocation will be replayed so we'll end up with an
53 	 *    uninitialized quota block.
54 	 *
55 	 * This is all fine; things are still consistent, and we haven't lost
56 	 * any quota information. Just don't complain about bad dquot blks.
57 	 */
58 	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
59 		return __this_address;
60 	if (ddq->d_version != XFS_DQUOT_VERSION)
61 		return __this_address;
62 
63 	if (type && ddq->d_flags != type)
64 		return __this_address;
65 	if (ddq->d_flags != XFS_DQ_USER &&
66 	    ddq->d_flags != XFS_DQ_PROJ &&
67 	    ddq->d_flags != XFS_DQ_GROUP)
68 		return __this_address;
69 
70 	if (id != -1 && id != be32_to_cpu(ddq->d_id))
71 		return __this_address;
72 
73 	if (!ddq->d_id)
74 		return NULL;
75 
76 	if (ddq->d_blk_softlimit &&
77 	    be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
78 	    !ddq->d_btimer)
79 		return __this_address;
80 
81 	if (ddq->d_ino_softlimit &&
82 	    be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
83 	    !ddq->d_itimer)
84 		return __this_address;
85 
86 	if (ddq->d_rtb_softlimit &&
87 	    be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
88 	    !ddq->d_rtbtimer)
89 		return __this_address;
90 
91 	return NULL;
92 }
93 
94 xfs_failaddr_t
95 xfs_dqblk_verify(
96 	struct xfs_mount	*mp,
97 	struct xfs_dqblk	*dqb,
98 	xfs_dqid_t	 	id,
99 	uint		 	type)	/* used only during quotacheck */
100 {
101 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
102 	    !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
103 		return __this_address;
104 
105 	return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
106 }
107 
108 /*
109  * Do some primitive error checking on ondisk dquot data structures.
110  */
111 void
112 xfs_dqblk_repair(
113 	struct xfs_mount	*mp,
114 	struct xfs_dqblk	*dqb,
115 	xfs_dqid_t		id,
116 	uint			type)
117 {
118 	/*
119 	 * Typically, a repair is only requested by quotacheck.
120 	 */
121 	ASSERT(id != -1);
122 	memset(dqb, 0, sizeof(xfs_dqblk_t));
123 
124 	dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
125 	dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
126 	dqb->dd_diskdq.d_flags = type;
127 	dqb->dd_diskdq.d_id = cpu_to_be32(id);
128 
129 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
130 		uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
131 		xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
132 				 XFS_DQUOT_CRC_OFF);
133 	}
134 }
135 
136 STATIC bool
137 xfs_dquot_buf_verify_crc(
138 	struct xfs_mount	*mp,
139 	struct xfs_buf		*bp,
140 	bool			readahead)
141 {
142 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
143 	int			ndquots;
144 	int			i;
145 
146 	if (!xfs_sb_version_hascrc(&mp->m_sb))
147 		return true;
148 
149 	/*
150 	 * if we are in log recovery, the quota subsystem has not been
151 	 * initialised so we have no quotainfo structure. In that case, we need
152 	 * to manually calculate the number of dquots in the buffer.
153 	 */
154 	if (mp->m_quotainfo)
155 		ndquots = mp->m_quotainfo->qi_dqperchunk;
156 	else
157 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
158 
159 	for (i = 0; i < ndquots; i++, d++) {
160 		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
161 				 XFS_DQUOT_CRC_OFF)) {
162 			if (!readahead)
163 				xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
164 					d, sizeof(*d), __this_address);
165 			return false;
166 		}
167 	}
168 	return true;
169 }
170 
171 STATIC xfs_failaddr_t
172 xfs_dquot_buf_verify(
173 	struct xfs_mount	*mp,
174 	struct xfs_buf		*bp,
175 	bool			readahead)
176 {
177 	struct xfs_dqblk	*dqb = bp->b_addr;
178 	xfs_failaddr_t		fa;
179 	xfs_dqid_t		id = 0;
180 	int			ndquots;
181 	int			i;
182 
183 	/*
184 	 * if we are in log recovery, the quota subsystem has not been
185 	 * initialised so we have no quotainfo structure. In that case, we need
186 	 * to manually calculate the number of dquots in the buffer.
187 	 */
188 	if (mp->m_quotainfo)
189 		ndquots = mp->m_quotainfo->qi_dqperchunk;
190 	else
191 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
192 
193 	/*
194 	 * On the first read of the buffer, verify that each dquot is valid.
195 	 * We don't know what the id of the dquot is supposed to be, just that
196 	 * they should be increasing monotonically within the buffer. If the
197 	 * first id is corrupt, then it will fail on the second dquot in the
198 	 * buffer so corruptions could point to the wrong dquot in this case.
199 	 */
200 	for (i = 0; i < ndquots; i++) {
201 		struct xfs_disk_dquot	*ddq;
202 
203 		ddq = &dqb[i].dd_diskdq;
204 
205 		if (i == 0)
206 			id = be32_to_cpu(ddq->d_id);
207 
208 		fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
209 		if (fa) {
210 			if (!readahead)
211 				xfs_buf_verifier_error(bp, -EFSCORRUPTED,
212 					__func__, &dqb[i],
213 					sizeof(struct xfs_dqblk), fa);
214 			return fa;
215 		}
216 	}
217 
218 	return NULL;
219 }
220 
221 static xfs_failaddr_t
222 xfs_dquot_buf_verify_struct(
223 	struct xfs_buf		*bp)
224 {
225 	struct xfs_mount	*mp = bp->b_mount;
226 
227 	return xfs_dquot_buf_verify(mp, bp, false);
228 }
229 
230 static void
231 xfs_dquot_buf_read_verify(
232 	struct xfs_buf		*bp)
233 {
234 	struct xfs_mount	*mp = bp->b_mount;
235 
236 	if (!xfs_dquot_buf_verify_crc(mp, bp, false))
237 		return;
238 	xfs_dquot_buf_verify(mp, bp, false);
239 }
240 
241 /*
242  * readahead errors are silent and simply leave the buffer as !done so a real
243  * read will then be run with the xfs_dquot_buf_ops verifier. See
244  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
245  * reporting the failure.
246  */
247 static void
248 xfs_dquot_buf_readahead_verify(
249 	struct xfs_buf	*bp)
250 {
251 	struct xfs_mount	*mp = bp->b_mount;
252 
253 	if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
254 	    xfs_dquot_buf_verify(mp, bp, true) != NULL) {
255 		xfs_buf_ioerror(bp, -EIO);
256 		bp->b_flags &= ~XBF_DONE;
257 	}
258 }
259 
260 /*
261  * we don't calculate the CRC here as that is done when the dquot is flushed to
262  * the buffer after the update is done. This ensures that the dquot in the
263  * buffer always has an up-to-date CRC value.
264  */
265 static void
266 xfs_dquot_buf_write_verify(
267 	struct xfs_buf		*bp)
268 {
269 	struct xfs_mount	*mp = bp->b_mount;
270 
271 	xfs_dquot_buf_verify(mp, bp, false);
272 }
273 
274 const struct xfs_buf_ops xfs_dquot_buf_ops = {
275 	.name = "xfs_dquot",
276 	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
277 		     cpu_to_be16(XFS_DQUOT_MAGIC) },
278 	.verify_read = xfs_dquot_buf_read_verify,
279 	.verify_write = xfs_dquot_buf_write_verify,
280 	.verify_struct = xfs_dquot_buf_verify_struct,
281 };
282 
283 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
284 	.name = "xfs_dquot_ra",
285 	.magic16 = { cpu_to_be16(XFS_DQUOT_MAGIC),
286 		     cpu_to_be16(XFS_DQUOT_MAGIC) },
287 	.verify_read = xfs_dquot_buf_readahead_verify,
288 	.verify_write = xfs_dquot_buf_write_verify,
289 };
290