summaryrefslogtreecommitdiff
path: root/fs/xfs/scrub/rtsummary.c
blob: fabd0ed9dfa67637686768dff5d27ef0ee78674d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <djwong@kernel.org>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_inode.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_rtbitmap.h"
#include "xfs_bit.h"
#include "xfs_bmap.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"
#include "scrub/xfile.h"

/*
 * Realtime Summary
 * ================
 *
 * We check the realtime summary by scanning the realtime bitmap file to create
 * a new summary file incore, and then we compare the computed version against
 * the ondisk version.  We use the 'xfile' functionality to store this
 * (potentially large) amount of data in pageable memory.
 */

struct xchk_rtsummary {
	struct xfs_rtalloc_args	args;

	uint64_t		rextents;
	uint64_t		rbmblocks;
	uint64_t		rsumsize;
	unsigned int		rsumlevels;

	/* Memory buffer for the summary comparison. */
	union xfs_suminfo_raw	words[];
};

/* Set us up to check the rtsummary file. */
int
xchk_setup_rtsummary(
	struct xfs_scrub	*sc)
{
	struct xfs_mount	*mp = sc->mp;
	char			*descr;
	struct xchk_rtsummary	*rts;
	int			error;

	rts = kvzalloc(struct_size(rts, words, mp->m_blockwsize),
			XCHK_GFP_FLAGS);
	if (!rts)
		return -ENOMEM;
	sc->buf = rts;

	/*
	 * Create an xfile to construct a new rtsummary file.  The xfile allows
	 * us to avoid pinning kernel memory for this purpose.
	 */
	descr = xchk_xfile_descr(sc, "realtime summary file");
	error = xfile_create(descr, mp->m_rsumsize, &sc->xfile);
	kfree(descr);
	if (error)
		return error;

	error = xchk_trans_alloc(sc, 0);
	if (error)
		return error;

	error = xchk_install_live_inode(sc, mp->m_rsumip);
	if (error)
		return error;

	error = xchk_ino_dqattach(sc);
	if (error)
		return error;

	/*
	 * Locking order requires us to take the rtbitmap first.  We must be
	 * careful to unlock it ourselves when we are done with the rtbitmap
	 * file since the scrub infrastructure won't do that for us.  Only
	 * then we can lock the rtsummary inode.
	 */
	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
	xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);

	/*
	 * Now that we've locked the rtbitmap and rtsummary, we can't race with
	 * growfsrt trying to expand the summary or change the size of the rt
	 * volume.  Hence it is safe to compute and check the geometry values.
	 */
	if (mp->m_sb.sb_rblocks) {
		xfs_filblks_t	rsumblocks;
		int		rextslog;

		rts->rextents = xfs_rtb_to_rtx(mp, mp->m_sb.sb_rblocks);
		rextslog = xfs_compute_rextslog(rts->rextents);
		rts->rsumlevels = rextslog + 1;
		rts->rbmblocks = xfs_rtbitmap_blockcount(mp, rts->rextents);
		rsumblocks = xfs_rtsummary_blockcount(mp, rts->rsumlevels,
				rts->rbmblocks);
		rts->rsumsize = XFS_FSB_TO_B(mp, rsumblocks);
	}
	return 0;
}

/* Helper functions to record suminfo words in an xfile. */

static inline int
xfsum_load(
	struct xfs_scrub	*sc,
	xfs_rtsumoff_t		sumoff,
	union xfs_suminfo_raw	*rawinfo)
{
	return xfile_obj_load(sc->xfile, rawinfo,
			sizeof(union xfs_suminfo_raw),
			sumoff << XFS_WORDLOG);
}

static inline int
xfsum_store(
	struct xfs_scrub	*sc,
	xfs_rtsumoff_t		sumoff,
	const union xfs_suminfo_raw rawinfo)
{
	return xfile_obj_store(sc->xfile, &rawinfo,
			sizeof(union xfs_suminfo_raw),
			sumoff << XFS_WORDLOG);
}

static inline int
xfsum_copyout(
	struct xfs_scrub	*sc,
	xfs_rtsumoff_t		sumoff,
	union xfs_suminfo_raw	*rawinfo,
	unsigned int		nr_words)
{
	return xfile_obj_load(sc->xfile, rawinfo, nr_words << XFS_WORDLOG,
			sumoff << XFS_WORDLOG);
}

static inline xfs_suminfo_t
xchk_rtsum_inc(
	struct xfs_mount	*mp,
	union xfs_suminfo_raw	*v)
{
	v->old += 1;
	return v->old;
}

/* Update the summary file to reflect the free extent that we've accumulated. */
STATIC int
xchk_rtsum_record_free(
	struct xfs_mount		*mp,
	struct xfs_trans		*tp,
	const struct xfs_rtalloc_rec	*rec,
	void				*priv)
{
	struct xfs_scrub		*sc = priv;
	xfs_fileoff_t			rbmoff;
	xfs_rtblock_t			rtbno;
	xfs_filblks_t			rtlen;
	xfs_rtsumoff_t			offs;
	unsigned int			lenlog;
	union xfs_suminfo_raw		v;
	xfs_suminfo_t			value;
	int				error = 0;

	if (xchk_should_terminate(sc, &error))
		return error;

	/* Compute the relevant location in the rtsum file. */
	rbmoff = xfs_rtx_to_rbmblock(mp, rec->ar_startext);
	lenlog = xfs_highbit64(rec->ar_extcount);
	offs = xfs_rtsumoffs(mp, lenlog, rbmoff);

	rtbno = xfs_rtx_to_rtb(mp, rec->ar_startext);
	rtlen = xfs_rtx_to_rtb(mp, rec->ar_extcount);

	if (!xfs_verify_rtbext(mp, rtbno, rtlen)) {
		xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
		return -EFSCORRUPTED;
	}

	/* Bump the summary count. */
	error = xfsum_load(sc, offs, &v);
	if (error)
		return error;

	value = xchk_rtsum_inc(sc->mp, &v);
	trace_xchk_rtsum_record_free(mp, rec->ar_startext, rec->ar_extcount,
			lenlog, offs, value);

	return xfsum_store(sc, offs, v);
}

/* Compute the realtime summary from the realtime bitmap. */
STATIC int
xchk_rtsum_compute(
	struct xfs_scrub	*sc)
{
	struct xfs_mount	*mp = sc->mp;
	unsigned long long	rtbmp_blocks;

	/* If the bitmap size doesn't match the computed size, bail. */
	rtbmp_blocks = xfs_rtbitmap_blockcount(mp, mp->m_sb.sb_rextents);
	if (XFS_FSB_TO_B(mp, rtbmp_blocks) != mp->m_rbmip->i_disk_size)
		return -EFSCORRUPTED;

	return xfs_rtalloc_query_all(sc->mp, sc->tp, xchk_rtsum_record_free,
			sc);
}

/* Compare the rtsummary file against the one we computed. */
STATIC int
xchk_rtsum_compare(
	struct xfs_scrub	*sc)
{
	struct xfs_bmbt_irec	map;
	struct xfs_iext_cursor	icur;

	struct xfs_mount	*mp = sc->mp;
	struct xfs_inode	*ip = sc->ip;
	struct xchk_rtsummary	*rts = sc->buf;
	xfs_fileoff_t		off = 0;
	xfs_fileoff_t		endoff;
	xfs_rtsumoff_t		sumoff = 0;
	int			error = 0;

	rts->args.mp = sc->mp;
	rts->args.tp = sc->tp;

	/* Mappings may not cross or lie beyond EOF. */
	endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);
	if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {
		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);
		return 0;
	}

	while (off < endoff) {
		int		nmap = 1;

		if (xchk_should_terminate(sc, &error))
			return error;
		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
			return 0;

		/* Make sure we have a written extent. */
		error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,
				XFS_DATA_FORK);
		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
			return error;

		if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
			return 0;
		}

		off += map.br_blockcount;
	}

	for (off = 0; off < endoff; off++) {
		union xfs_suminfo_raw	*ondisk_info;

		/* Read a block's worth of ondisk rtsummary file. */
		error = xfs_rtsummary_read_buf(&rts->args, off);
		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
			return error;

		/* Read a block's worth of computed rtsummary file. */
		error = xfsum_copyout(sc, sumoff, rts->words, mp->m_blockwsize);
		if (error) {
			xfs_rtbuf_cache_relse(&rts->args);
			return error;
		}

		ondisk_info = xfs_rsumblock_infoptr(&rts->args, 0);
		if (memcmp(ondisk_info, rts->words,
					mp->m_blockwsize << XFS_WORDLOG) != 0) {
			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
			xfs_rtbuf_cache_relse(&rts->args);
			return error;
		}

		xfs_rtbuf_cache_relse(&rts->args);
		sumoff += mp->m_blockwsize;
	}

	return 0;
}

/* Scrub the realtime summary. */
int
xchk_rtsummary(
	struct xfs_scrub	*sc)
{
	struct xfs_mount	*mp = sc->mp;
	struct xchk_rtsummary	*rts = sc->buf;
	int			error = 0;

	/* Is sb_rextents correct? */
	if (mp->m_sb.sb_rextents != rts->rextents) {
		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
		goto out_rbm;
	}

	/* Is m_rsumlevels correct? */
	if (mp->m_rsumlevels != rts->rsumlevels) {
		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);
		goto out_rbm;
	}

	/* Is m_rsumsize correct? */
	if (mp->m_rsumsize != rts->rsumsize) {
		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);
		goto out_rbm;
	}

	/* The summary file length must be aligned to an fsblock. */
	if (mp->m_rsumip->i_disk_size & mp->m_blockmask) {
		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);
		goto out_rbm;
	}

	/*
	 * Is the summary file itself large enough to handle the rt volume?
	 * growfsrt expands the summary file before updating sb_rextents, so
	 * the file can be larger than rsumsize.
	 */
	if (mp->m_rsumip->i_disk_size < rts->rsumsize) {
		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);
		goto out_rbm;
	}

	/* Invoke the fork scrubber. */
	error = xchk_metadata_inode_forks(sc);
	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
		goto out_rbm;

	/* Construct the new summary file from the rtbitmap. */
	error = xchk_rtsum_compute(sc);
	if (error == -EFSCORRUPTED) {
		/*
		 * EFSCORRUPTED means the rtbitmap is corrupt, which is an xref
		 * error since we're checking the summary file.
		 */
		xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
		error = 0;
		goto out_rbm;
	}
	if (error)
		goto out_rbm;

	/* Does the computed summary file match the actual rtsummary file? */
	error = xchk_rtsum_compare(sc);

out_rbm:
	/* Unlock the rtbitmap since we're done with it. */
	xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
	return error;
}