xref: /openbmc/linux/fs/xfs/scrub/rmap.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
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_btree.h"
13 #include "xfs_rmap.h"
14 #include "xfs_refcount.h"
15 #include "scrub/scrub.h"
16 #include "scrub/common.h"
17 #include "scrub/btree.h"
18 
19 /*
20  * Set us up to scrub reverse mapping btrees.
21  */
22 int
23 xchk_setup_ag_rmapbt(
24 	struct xfs_scrub	*sc,
25 	struct xfs_inode	*ip)
26 {
27 	return xchk_setup_ag_btree(sc, ip, false);
28 }
29 
30 /* Reverse-mapping scrubber. */
31 
32 /* Cross-reference a rmap against the refcount btree. */
33 STATIC void
34 xchk_rmapbt_xref_refc(
35 	struct xfs_scrub	*sc,
36 	struct xfs_rmap_irec	*irec)
37 {
38 	xfs_agblock_t		fbno;
39 	xfs_extlen_t		flen;
40 	bool			non_inode;
41 	bool			is_bmbt;
42 	bool			is_attr;
43 	bool			is_unwritten;
44 	int			error;
45 
46 	if (!sc->sa.refc_cur || xchk_skip_xref(sc->sm))
47 		return;
48 
49 	non_inode = XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
50 	is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
51 	is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
52 	is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
53 
54 	/* If this is shared, must be a data fork extent. */
55 	error = xfs_refcount_find_shared(sc->sa.refc_cur, irec->rm_startblock,
56 			irec->rm_blockcount, &fbno, &flen, false);
57 	if (!xchk_should_check_xref(sc, &error, &sc->sa.refc_cur))
58 		return;
59 	if (flen != 0 && (non_inode || is_attr || is_bmbt || is_unwritten))
60 		xchk_btree_xref_set_corrupt(sc, sc->sa.refc_cur, 0);
61 }
62 
63 /* Cross-reference with the other btrees. */
64 STATIC void
65 xchk_rmapbt_xref(
66 	struct xfs_scrub	*sc,
67 	struct xfs_rmap_irec	*irec)
68 {
69 	xfs_agblock_t		agbno = irec->rm_startblock;
70 	xfs_extlen_t		len = irec->rm_blockcount;
71 
72 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
73 		return;
74 
75 	xchk_xref_is_used_space(sc, agbno, len);
76 	if (irec->rm_owner == XFS_RMAP_OWN_INODES)
77 		xchk_xref_is_inode_chunk(sc, agbno, len);
78 	else
79 		xchk_xref_is_not_inode_chunk(sc, agbno, len);
80 	if (irec->rm_owner == XFS_RMAP_OWN_COW)
81 		xchk_xref_is_cow_staging(sc, irec->rm_startblock,
82 				irec->rm_blockcount);
83 	else
84 		xchk_rmapbt_xref_refc(sc, irec);
85 }
86 
87 /* Scrub an rmapbt record. */
88 STATIC int
89 xchk_rmapbt_rec(
90 	struct xchk_btree	*bs,
91 	union xfs_btree_rec	*rec)
92 {
93 	struct xfs_mount	*mp = bs->cur->bc_mp;
94 	struct xfs_rmap_irec	irec;
95 	xfs_agnumber_t		agno = bs->cur->bc_ag.agno;
96 	bool			non_inode;
97 	bool			is_unwritten;
98 	bool			is_bmbt;
99 	bool			is_attr;
100 	int			error;
101 
102 	error = xfs_rmap_btrec_to_irec(rec, &irec);
103 	if (!xchk_btree_process_error(bs->sc, bs->cur, 0, &error))
104 		goto out;
105 
106 	/* Check extent. */
107 	if (irec.rm_startblock + irec.rm_blockcount <= irec.rm_startblock)
108 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
109 
110 	if (irec.rm_owner == XFS_RMAP_OWN_FS) {
111 		/*
112 		 * xfs_verify_agbno returns false for static fs metadata.
113 		 * Since that only exists at the start of the AG, validate
114 		 * that by hand.
115 		 */
116 		if (irec.rm_startblock != 0 ||
117 		    irec.rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
118 			xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
119 	} else {
120 		/*
121 		 * Otherwise we must point somewhere past the static metadata
122 		 * but before the end of the FS.  Run the regular check.
123 		 */
124 		if (!xfs_verify_agbno(mp, agno, irec.rm_startblock) ||
125 		    !xfs_verify_agbno(mp, agno, irec.rm_startblock +
126 				irec.rm_blockcount - 1))
127 			xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
128 	}
129 
130 	/* Check flags. */
131 	non_inode = XFS_RMAP_NON_INODE_OWNER(irec.rm_owner);
132 	is_bmbt = irec.rm_flags & XFS_RMAP_BMBT_BLOCK;
133 	is_attr = irec.rm_flags & XFS_RMAP_ATTR_FORK;
134 	is_unwritten = irec.rm_flags & XFS_RMAP_UNWRITTEN;
135 
136 	if (is_bmbt && irec.rm_offset != 0)
137 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
138 
139 	if (non_inode && irec.rm_offset != 0)
140 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
141 
142 	if (is_unwritten && (is_bmbt || non_inode || is_attr))
143 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
144 
145 	if (non_inode && (is_bmbt || is_unwritten || is_attr))
146 		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
147 
148 	if (!non_inode) {
149 		if (!xfs_verify_ino(mp, irec.rm_owner))
150 			xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
151 	} else {
152 		/* Non-inode owner within the magic values? */
153 		if (irec.rm_owner <= XFS_RMAP_OWN_MIN ||
154 		    irec.rm_owner > XFS_RMAP_OWN_FS)
155 			xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
156 	}
157 
158 	xchk_rmapbt_xref(bs->sc, &irec);
159 out:
160 	return error;
161 }
162 
163 /* Scrub the rmap btree for some AG. */
164 int
165 xchk_rmapbt(
166 	struct xfs_scrub	*sc)
167 {
168 	return xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
169 			&XFS_RMAP_OINFO_AG, NULL);
170 }
171 
172 /* xref check that the extent is owned by a given owner */
173 static inline void
174 xchk_xref_check_owner(
175 	struct xfs_scrub		*sc,
176 	xfs_agblock_t			bno,
177 	xfs_extlen_t			len,
178 	const struct xfs_owner_info	*oinfo,
179 	bool				should_have_rmap)
180 {
181 	bool				has_rmap;
182 	int				error;
183 
184 	if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
185 		return;
186 
187 	error = xfs_rmap_record_exists(sc->sa.rmap_cur, bno, len, oinfo,
188 			&has_rmap);
189 	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
190 		return;
191 	if (has_rmap != should_have_rmap)
192 		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
193 }
194 
195 /* xref check that the extent is owned by a given owner */
196 void
197 xchk_xref_is_owned_by(
198 	struct xfs_scrub		*sc,
199 	xfs_agblock_t			bno,
200 	xfs_extlen_t			len,
201 	const struct xfs_owner_info	*oinfo)
202 {
203 	xchk_xref_check_owner(sc, bno, len, oinfo, true);
204 }
205 
206 /* xref check that the extent is not owned by a given owner */
207 void
208 xchk_xref_is_not_owned_by(
209 	struct xfs_scrub		*sc,
210 	xfs_agblock_t			bno,
211 	xfs_extlen_t			len,
212 	const struct xfs_owner_info	*oinfo)
213 {
214 	xchk_xref_check_owner(sc, bno, len, oinfo, false);
215 }
216 
217 /* xref check that the extent has no reverse mapping at all */
218 void
219 xchk_xref_has_no_owner(
220 	struct xfs_scrub	*sc,
221 	xfs_agblock_t		bno,
222 	xfs_extlen_t		len)
223 {
224 	bool			has_rmap;
225 	int			error;
226 
227 	if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
228 		return;
229 
230 	error = xfs_rmap_has_record(sc->sa.rmap_cur, bno, len, &has_rmap);
231 	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
232 		return;
233 	if (has_rmap)
234 		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
235 }
236