xref: /openbmc/linux/fs/xfs/libxfs/xfs_dquot_buf.c (revision d236d361)
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 int
46 xfs_dqcheck(
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 	const char	 *str)
53 {
54 	xfs_dqblk_t	 *d = (xfs_dqblk_t *)ddq;
55 	int		errs = 0;
56 
57 	/*
58 	 * We can encounter an uninitialized dquot buffer for 2 reasons:
59 	 * 1. If we crash while deleting the quotainode(s), and those blks got
60 	 *    used for user data. This is because we take the path of regular
61 	 *    file deletion; however, the size field of quotainodes is never
62 	 *    updated, so all the tricks that we play in itruncate_finish
63 	 *    don't quite matter.
64 	 *
65 	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
66 	 *    But the allocation will be replayed so we'll end up with an
67 	 *    uninitialized quota block.
68 	 *
69 	 * This is all fine; things are still consistent, and we haven't lost
70 	 * any quota information. Just don't complain about bad dquot blks.
71 	 */
72 	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC)) {
73 		if (flags & XFS_QMOPT_DOWARN)
74 			xfs_alert(mp,
75 			"%s : XFS dquot ID 0x%x, magic 0x%x != 0x%x",
76 			str, id, be16_to_cpu(ddq->d_magic), XFS_DQUOT_MAGIC);
77 		errs++;
78 	}
79 	if (ddq->d_version != XFS_DQUOT_VERSION) {
80 		if (flags & XFS_QMOPT_DOWARN)
81 			xfs_alert(mp,
82 			"%s : XFS dquot ID 0x%x, version 0x%x != 0x%x",
83 			str, id, ddq->d_version, XFS_DQUOT_VERSION);
84 		errs++;
85 	}
86 
87 	if (ddq->d_flags != XFS_DQ_USER &&
88 	    ddq->d_flags != XFS_DQ_PROJ &&
89 	    ddq->d_flags != XFS_DQ_GROUP) {
90 		if (flags & XFS_QMOPT_DOWARN)
91 			xfs_alert(mp,
92 			"%s : XFS dquot ID 0x%x, unknown flags 0x%x",
93 			str, id, ddq->d_flags);
94 		errs++;
95 	}
96 
97 	if (id != -1 && id != be32_to_cpu(ddq->d_id)) {
98 		if (flags & XFS_QMOPT_DOWARN)
99 			xfs_alert(mp,
100 			"%s : ondisk-dquot 0x%p, ID mismatch: "
101 			"0x%x expected, found id 0x%x",
102 			str, ddq, id, be32_to_cpu(ddq->d_id));
103 		errs++;
104 	}
105 
106 	if (!errs && ddq->d_id) {
107 		if (ddq->d_blk_softlimit &&
108 		    be64_to_cpu(ddq->d_bcount) >
109 				be64_to_cpu(ddq->d_blk_softlimit)) {
110 			if (!ddq->d_btimer) {
111 				if (flags & XFS_QMOPT_DOWARN)
112 					xfs_alert(mp,
113 			"%s : Dquot ID 0x%x (0x%p) BLK TIMER NOT STARTED",
114 					str, (int)be32_to_cpu(ddq->d_id), ddq);
115 				errs++;
116 			}
117 		}
118 		if (ddq->d_ino_softlimit &&
119 		    be64_to_cpu(ddq->d_icount) >
120 				be64_to_cpu(ddq->d_ino_softlimit)) {
121 			if (!ddq->d_itimer) {
122 				if (flags & XFS_QMOPT_DOWARN)
123 					xfs_alert(mp,
124 			"%s : Dquot ID 0x%x (0x%p) INODE TIMER NOT STARTED",
125 					str, (int)be32_to_cpu(ddq->d_id), ddq);
126 				errs++;
127 			}
128 		}
129 		if (ddq->d_rtb_softlimit &&
130 		    be64_to_cpu(ddq->d_rtbcount) >
131 				be64_to_cpu(ddq->d_rtb_softlimit)) {
132 			if (!ddq->d_rtbtimer) {
133 				if (flags & XFS_QMOPT_DOWARN)
134 					xfs_alert(mp,
135 			"%s : Dquot ID 0x%x (0x%p) RTBLK TIMER NOT STARTED",
136 					str, (int)be32_to_cpu(ddq->d_id), ddq);
137 				errs++;
138 			}
139 		}
140 	}
141 
142 	if (!errs || !(flags & XFS_QMOPT_DQREPAIR))
143 		return errs;
144 
145 	if (flags & XFS_QMOPT_DOWARN)
146 		xfs_notice(mp, "Re-initializing dquot ID 0x%x", id);
147 
148 	/*
149 	 * Typically, a repair is only requested by quotacheck.
150 	 */
151 	ASSERT(id != -1);
152 	ASSERT(flags & XFS_QMOPT_DQREPAIR);
153 	memset(d, 0, sizeof(xfs_dqblk_t));
154 
155 	d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
156 	d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
157 	d->dd_diskdq.d_flags = type;
158 	d->dd_diskdq.d_id = cpu_to_be32(id);
159 
160 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
161 		uuid_copy(&d->dd_uuid, &mp->m_sb.sb_meta_uuid);
162 		xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
163 				 XFS_DQUOT_CRC_OFF);
164 	}
165 
166 	return errs;
167 }
168 
169 STATIC bool
170 xfs_dquot_buf_verify_crc(
171 	struct xfs_mount	*mp,
172 	struct xfs_buf		*bp)
173 {
174 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
175 	int			ndquots;
176 	int			i;
177 
178 	if (!xfs_sb_version_hascrc(&mp->m_sb))
179 		return true;
180 
181 	/*
182 	 * if we are in log recovery, the quota subsystem has not been
183 	 * initialised so we have no quotainfo structure. In that case, we need
184 	 * to manually calculate the number of dquots in the buffer.
185 	 */
186 	if (mp->m_quotainfo)
187 		ndquots = mp->m_quotainfo->qi_dqperchunk;
188 	else
189 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
190 
191 	for (i = 0; i < ndquots; i++, d++) {
192 		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
193 				 XFS_DQUOT_CRC_OFF))
194 			return false;
195 		if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_meta_uuid))
196 			return false;
197 	}
198 	return true;
199 }
200 
201 STATIC bool
202 xfs_dquot_buf_verify(
203 	struct xfs_mount	*mp,
204 	struct xfs_buf		*bp,
205 	int			warn)
206 {
207 	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
208 	xfs_dqid_t		id = 0;
209 	int			ndquots;
210 	int			i;
211 
212 	/*
213 	 * if we are in log recovery, the quota subsystem has not been
214 	 * initialised so we have no quotainfo structure. In that case, we need
215 	 * to manually calculate the number of dquots in the buffer.
216 	 */
217 	if (mp->m_quotainfo)
218 		ndquots = mp->m_quotainfo->qi_dqperchunk;
219 	else
220 		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
221 
222 	/*
223 	 * On the first read of the buffer, verify that each dquot is valid.
224 	 * We don't know what the id of the dquot is supposed to be, just that
225 	 * they should be increasing monotonically within the buffer. If the
226 	 * first id is corrupt, then it will fail on the second dquot in the
227 	 * buffer so corruptions could point to the wrong dquot in this case.
228 	 */
229 	for (i = 0; i < ndquots; i++) {
230 		struct xfs_disk_dquot	*ddq;
231 		int			error;
232 
233 		ddq = &d[i].dd_diskdq;
234 
235 		if (i == 0)
236 			id = be32_to_cpu(ddq->d_id);
237 
238 		error = xfs_dqcheck(mp, ddq, id + i, 0, warn, __func__);
239 		if (error)
240 			return false;
241 	}
242 	return true;
243 }
244 
245 static void
246 xfs_dquot_buf_read_verify(
247 	struct xfs_buf	*bp)
248 {
249 	struct xfs_mount	*mp = bp->b_target->bt_mount;
250 
251 	if (!xfs_dquot_buf_verify_crc(mp, bp))
252 		xfs_buf_ioerror(bp, -EFSBADCRC);
253 	else if (!xfs_dquot_buf_verify(mp, bp, XFS_QMOPT_DOWARN))
254 		xfs_buf_ioerror(bp, -EFSCORRUPTED);
255 
256 	if (bp->b_error)
257 		xfs_verifier_error(bp);
258 }
259 
260 /*
261  * readahead errors are silent and simply leave the buffer as !done so a real
262  * read will then be run with the xfs_dquot_buf_ops verifier. See
263  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
264  * reporting the failure.
265  */
266 static void
267 xfs_dquot_buf_readahead_verify(
268 	struct xfs_buf	*bp)
269 {
270 	struct xfs_mount	*mp = bp->b_target->bt_mount;
271 
272 	if (!xfs_dquot_buf_verify_crc(mp, bp) ||
273 	    !xfs_dquot_buf_verify(mp, bp, 0)) {
274 		xfs_buf_ioerror(bp, -EIO);
275 		bp->b_flags &= ~XBF_DONE;
276 	}
277 }
278 
279 /*
280  * we don't calculate the CRC here as that is done when the dquot is flushed to
281  * the buffer after the update is done. This ensures that the dquot in the
282  * buffer always has an up-to-date CRC value.
283  */
284 static void
285 xfs_dquot_buf_write_verify(
286 	struct xfs_buf	*bp)
287 {
288 	struct xfs_mount	*mp = bp->b_target->bt_mount;
289 
290 	if (!xfs_dquot_buf_verify(mp, bp, XFS_QMOPT_DOWARN)) {
291 		xfs_buf_ioerror(bp, -EFSCORRUPTED);
292 		xfs_verifier_error(bp);
293 		return;
294 	}
295 }
296 
297 const struct xfs_buf_ops xfs_dquot_buf_ops = {
298 	.name = "xfs_dquot",
299 	.verify_read = xfs_dquot_buf_read_verify,
300 	.verify_write = xfs_dquot_buf_write_verify,
301 };
302 
303 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
304 	.name = "xfs_dquot_ra",
305 	.verify_read = xfs_dquot_buf_readahead_verify,
306 	.verify_write = xfs_dquot_buf_write_verify,
307 };
308