xref: /linux/fs/xfs/scrub/rtrmap.c (revision b477ff98d903618a1ab8247861f2ea6e70c0f0f8)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2018-2024 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <djwong@kernel.org>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_defer.h"
13 #include "xfs_btree.h"
14 #include "xfs_bit.h"
15 #include "xfs_log_format.h"
16 #include "xfs_trans.h"
17 #include "xfs_sb.h"
18 #include "xfs_rmap.h"
19 #include "xfs_rmap_btree.h"
20 #include "xfs_rtrmap_btree.h"
21 #include "xfs_inode.h"
22 #include "xfs_rtalloc.h"
23 #include "xfs_rtgroup.h"
24 #include "xfs_metafile.h"
25 #include "xfs_refcount.h"
26 #include "scrub/xfs_scrub.h"
27 #include "scrub/scrub.h"
28 #include "scrub/common.h"
29 #include "scrub/btree.h"
30 #include "scrub/trace.h"
31 #include "scrub/repair.h"
32 
33 /* Set us up with the realtime metadata locked. */
34 int
xchk_setup_rtrmapbt(struct xfs_scrub * sc)35 xchk_setup_rtrmapbt(
36 	struct xfs_scrub	*sc)
37 {
38 	int			error;
39 
40 	if (xchk_need_intent_drain(sc))
41 		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
42 
43 	if (xchk_could_repair(sc)) {
44 		error = xrep_setup_rtrmapbt(sc);
45 		if (error)
46 			return error;
47 	}
48 
49 	error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr);
50 	if (error)
51 		return error;
52 
53 	error = xchk_setup_rt(sc);
54 	if (error)
55 		return error;
56 
57 	error = xchk_install_live_inode(sc, rtg_rmap(sc->sr.rtg));
58 	if (error)
59 		return error;
60 
61 	return xchk_rtgroup_lock(sc, &sc->sr, XCHK_RTGLOCK_ALL);
62 }
63 
64 /* Realtime reverse mapping. */
65 
66 struct xchk_rtrmap {
67 	/*
68 	 * The furthest-reaching of the rmapbt records that we've already
69 	 * processed.  This enables us to detect overlapping records for space
70 	 * allocations that cannot be shared.
71 	 */
72 	struct xfs_rmap_irec	overlap_rec;
73 
74 	/*
75 	 * The previous rmapbt record, so that we can check for two records
76 	 * that could be one.
77 	 */
78 	struct xfs_rmap_irec	prev_rec;
79 };
80 
81 static inline bool
xchk_rtrmapbt_is_shareable(struct xfs_scrub * sc,const struct xfs_rmap_irec * irec)82 xchk_rtrmapbt_is_shareable(
83 	struct xfs_scrub		*sc,
84 	const struct xfs_rmap_irec	*irec)
85 {
86 	if (!xfs_has_rtreflink(sc->mp))
87 		return false;
88 	if (irec->rm_flags & XFS_RMAP_UNWRITTEN)
89 		return false;
90 	return true;
91 }
92 
93 /* Flag failures for records that overlap but cannot. */
94 STATIC void
xchk_rtrmapbt_check_overlapping(struct xchk_btree * bs,struct xchk_rtrmap * cr,const struct xfs_rmap_irec * irec)95 xchk_rtrmapbt_check_overlapping(
96 	struct xchk_btree		*bs,
97 	struct xchk_rtrmap		*cr,
98 	const struct xfs_rmap_irec	*irec)
99 {
100 	xfs_rtblock_t			pnext, inext;
101 
102 	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
103 		return;
104 
105 	/* No previous record? */
106 	if (cr->overlap_rec.rm_blockcount == 0)
107 		goto set_prev;
108 
109 	/* Do overlap_rec and irec overlap? */
110 	pnext = cr->overlap_rec.rm_startblock + cr->overlap_rec.rm_blockcount;
111 	if (pnext <= irec->rm_startblock)
112 		goto set_prev;
113 
114 	/* Overlap is only allowed if both records are data fork mappings. */
115 	if (!xchk_rtrmapbt_is_shareable(bs->sc, &cr->overlap_rec) ||
116 	    !xchk_rtrmapbt_is_shareable(bs->sc, irec))
117 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
118 
119 	/* Save whichever rmap record extends furthest. */
120 	inext = irec->rm_startblock + irec->rm_blockcount;
121 	if (pnext > inext)
122 		return;
123 
124 set_prev:
125 	memcpy(&cr->overlap_rec, irec, sizeof(struct xfs_rmap_irec));
126 }
127 
128 /* Decide if two reverse-mapping records can be merged. */
129 static inline bool
xchk_rtrmap_mergeable(struct xchk_rtrmap * cr,const struct xfs_rmap_irec * r2)130 xchk_rtrmap_mergeable(
131 	struct xchk_rtrmap		*cr,
132 	const struct xfs_rmap_irec	*r2)
133 {
134 	const struct xfs_rmap_irec	*r1 = &cr->prev_rec;
135 
136 	/* Ignore if prev_rec is not yet initialized. */
137 	if (cr->prev_rec.rm_blockcount == 0)
138 		return false;
139 
140 	if (r1->rm_owner != r2->rm_owner)
141 		return false;
142 	if (r1->rm_startblock + r1->rm_blockcount != r2->rm_startblock)
143 		return false;
144 	if ((unsigned long long)r1->rm_blockcount + r2->rm_blockcount >
145 	    XFS_RMAP_LEN_MAX)
146 		return false;
147 	if (r1->rm_flags != r2->rm_flags)
148 		return false;
149 	return r1->rm_offset + r1->rm_blockcount == r2->rm_offset;
150 }
151 
152 /* Flag failures for records that could be merged. */
153 STATIC void
xchk_rtrmapbt_check_mergeable(struct xchk_btree * bs,struct xchk_rtrmap * cr,const struct xfs_rmap_irec * irec)154 xchk_rtrmapbt_check_mergeable(
155 	struct xchk_btree		*bs,
156 	struct xchk_rtrmap		*cr,
157 	const struct xfs_rmap_irec	*irec)
158 {
159 	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
160 		return;
161 
162 	if (xchk_rtrmap_mergeable(cr, irec))
163 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
164 
165 	memcpy(&cr->prev_rec, irec, sizeof(struct xfs_rmap_irec));
166 }
167 
168 /* Cross-reference a rmap against the refcount btree. */
169 STATIC void
xchk_rtrmapbt_xref_rtrefc(struct xfs_scrub * sc,struct xfs_rmap_irec * irec)170 xchk_rtrmapbt_xref_rtrefc(
171 	struct xfs_scrub	*sc,
172 	struct xfs_rmap_irec	*irec)
173 {
174 	xfs_rgblock_t		fbno;
175 	xfs_extlen_t		flen;
176 	bool			is_inode;
177 	bool			is_bmbt;
178 	bool			is_attr;
179 	bool			is_unwritten;
180 	int			error;
181 
182 	if (!sc->sr.refc_cur || xchk_skip_xref(sc->sm))
183 		return;
184 
185 	is_inode = !XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
186 	is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
187 	is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
188 	is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
189 
190 	/* If this is shared, must be a data fork extent. */
191 	error = xfs_refcount_find_shared(sc->sr.refc_cur, irec->rm_startblock,
192 			irec->rm_blockcount, &fbno, &flen, false);
193 	if (!xchk_should_check_xref(sc, &error, &sc->sr.refc_cur))
194 		return;
195 	if (flen != 0 && (!is_inode || is_attr || is_bmbt || is_unwritten))
196 		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
197 }
198 
199 /* Cross-reference with other metadata. */
200 STATIC void
xchk_rtrmapbt_xref(struct xfs_scrub * sc,struct xfs_rmap_irec * irec)201 xchk_rtrmapbt_xref(
202 	struct xfs_scrub	*sc,
203 	struct xfs_rmap_irec	*irec)
204 {
205 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
206 		return;
207 
208 	xchk_xref_is_used_rt_space(sc,
209 			xfs_rgbno_to_rtb(sc->sr.rtg, irec->rm_startblock),
210 			irec->rm_blockcount);
211 	if (irec->rm_owner == XFS_RMAP_OWN_COW)
212 		xchk_xref_is_cow_staging(sc, irec->rm_startblock,
213 				irec->rm_blockcount);
214 	else
215 		xchk_rtrmapbt_xref_rtrefc(sc, irec);
216 }
217 
218 /* Scrub a realtime rmapbt record. */
219 STATIC int
xchk_rtrmapbt_rec(struct xchk_btree * bs,const union xfs_btree_rec * rec)220 xchk_rtrmapbt_rec(
221 	struct xchk_btree		*bs,
222 	const union xfs_btree_rec	*rec)
223 {
224 	struct xchk_rtrmap		*cr = bs->private;
225 	struct xfs_rmap_irec		irec;
226 
227 	if (xfs_rmap_btrec_to_irec(rec, &irec) != NULL ||
228 	    xfs_rtrmap_check_irec(to_rtg(bs->cur->bc_group), &irec) != NULL) {
229 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
230 		return 0;
231 	}
232 
233 	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
234 		return 0;
235 
236 	xchk_rtrmapbt_check_mergeable(bs, cr, &irec);
237 	xchk_rtrmapbt_check_overlapping(bs, cr, &irec);
238 	xchk_rtrmapbt_xref(bs->sc, &irec);
239 	return 0;
240 }
241 
242 /* Scrub the realtime rmap btree. */
243 int
xchk_rtrmapbt(struct xfs_scrub * sc)244 xchk_rtrmapbt(
245 	struct xfs_scrub	*sc)
246 {
247 	struct xfs_inode	*ip = rtg_rmap(sc->sr.rtg);
248 	struct xfs_owner_info	oinfo;
249 	struct xchk_rtrmap	cr = { };
250 	int			error;
251 
252 	error = xchk_metadata_inode_forks(sc);
253 	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
254 		return error;
255 
256 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, XFS_DATA_FORK);
257 	return xchk_btree(sc, sc->sr.rmap_cur, xchk_rtrmapbt_rec, &oinfo, &cr);
258 }
259 
260 /* xref check that the extent has no realtime reverse mapping at all */
261 void
xchk_xref_has_no_rt_owner(struct xfs_scrub * sc,xfs_rgblock_t bno,xfs_extlen_t len)262 xchk_xref_has_no_rt_owner(
263 	struct xfs_scrub	*sc,
264 	xfs_rgblock_t		bno,
265 	xfs_extlen_t		len)
266 {
267 	enum xbtree_recpacking	outcome;
268 	int			error;
269 
270 	if (!sc->sr.rmap_cur || xchk_skip_xref(sc->sm))
271 		return;
272 
273 	error = xfs_rmap_has_records(sc->sr.rmap_cur, bno, len, &outcome);
274 	if (!xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur))
275 		return;
276 	if (outcome != XBTREE_RECPACKING_EMPTY)
277 		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
278 }
279 
280 /* xref check that the extent is completely mapped */
281 void
xchk_xref_has_rt_owner(struct xfs_scrub * sc,xfs_rgblock_t bno,xfs_extlen_t len)282 xchk_xref_has_rt_owner(
283 	struct xfs_scrub	*sc,
284 	xfs_rgblock_t		bno,
285 	xfs_extlen_t		len)
286 {
287 	enum xbtree_recpacking	outcome;
288 	int			error;
289 
290 	if (!sc->sr.rmap_cur || xchk_skip_xref(sc->sm))
291 		return;
292 
293 	error = xfs_rmap_has_records(sc->sr.rmap_cur, bno, len, &outcome);
294 	if (!xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur))
295 		return;
296 	if (outcome != XBTREE_RECPACKING_FULL)
297 		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
298 }
299 
300 /* xref check that the extent is only owned by a given owner */
301 void
xchk_xref_is_only_rt_owned_by(struct xfs_scrub * sc,xfs_agblock_t bno,xfs_extlen_t len,const struct xfs_owner_info * oinfo)302 xchk_xref_is_only_rt_owned_by(
303 	struct xfs_scrub		*sc,
304 	xfs_agblock_t			bno,
305 	xfs_extlen_t			len,
306 	const struct xfs_owner_info	*oinfo)
307 {
308 	struct xfs_rmap_matches		res;
309 	int				error;
310 
311 	if (!sc->sr.rmap_cur || xchk_skip_xref(sc->sm))
312 		return;
313 
314 	error = xfs_rmap_count_owners(sc->sr.rmap_cur, bno, len, oinfo, &res);
315 	if (!xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur))
316 		return;
317 	if (res.matches != 1)
318 		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
319 	if (res.bad_non_owner_matches)
320 		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
321 	if (res.non_owner_matches)
322 		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
323 }
324