1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2019-2023 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_btree.h"
13 #include "xfs_ag.h"
14 #include "xfs_health.h"
15 #include "scrub/scrub.h"
16 #include "scrub/health.h"
17 #include "scrub/common.h"
18
19 /*
20 * Scrub and In-Core Filesystem Health Assessments
21 * ===============================================
22 *
23 * Online scrub and repair have the time and the ability to perform stronger
24 * checks than we can do from the metadata verifiers, because they can
25 * cross-reference records between data structures. Therefore, scrub is in a
26 * good position to update the online filesystem health assessments to reflect
27 * the good/bad state of the data structure.
28 *
29 * We therefore extend scrub in the following ways to achieve this:
30 *
31 * 1. Create a "sick_mask" field in the scrub context. When we're setting up a
32 * scrub call, set this to the default XFS_SICK_* flag(s) for the selected
33 * scrub type (call it A). Scrub and repair functions can override the default
34 * sick_mask value if they choose.
35 *
36 * 2. If the scrubber returns a runtime error code, we exit making no changes
37 * to the incore sick state.
38 *
39 * 3. If the scrubber finds that A is clean, use sick_mask to clear the incore
40 * sick flags before exiting.
41 *
42 * 4. If the scrubber finds that A is corrupt, use sick_mask to set the incore
43 * sick flags. If the user didn't want to repair then we exit, leaving the
44 * metadata structure unfixed and the sick flag set.
45 *
46 * 5. Now we know that A is corrupt and the user wants to repair, so run the
47 * repairer. If the repairer returns an error code, we exit with that error
48 * code, having made no further changes to the incore sick state.
49 *
50 * 6. If repair rebuilds A correctly and the subsequent re-scrub of A is clean,
51 * use sick_mask to clear the incore sick flags. This should have the effect
52 * that A is no longer marked sick.
53 *
54 * 7. If repair rebuilds A incorrectly, the re-scrub will find it corrupt and
55 * use sick_mask to set the incore sick flags. This should have no externally
56 * visible effect since we already set them in step (4).
57 *
58 * There are some complications to this story, however. For certain types of
59 * complementary metadata indices (e.g. inobt/finobt), it is easier to rebuild
60 * both structures at the same time. The following principles apply to this
61 * type of repair strategy:
62 *
63 * 8. Any repair function that rebuilds multiple structures should update
64 * sick_mask_visible to reflect whatever other structures are rebuilt, and
65 * verify that all the rebuilt structures can pass a scrub check. The outcomes
66 * of 5-7 still apply, but with a sick_mask that covers everything being
67 * rebuilt.
68 */
69
70 /* Map our scrub type to a sick mask and a set of health update functions. */
71
72 enum xchk_health_group {
73 XHG_FS = 1,
74 XHG_RT,
75 XHG_AG,
76 XHG_INO,
77 };
78
79 struct xchk_health_map {
80 enum xchk_health_group group;
81 unsigned int sick_mask;
82 };
83
84 static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = {
85 [XFS_SCRUB_TYPE_SB] = { XHG_AG, XFS_SICK_AG_SB },
86 [XFS_SCRUB_TYPE_AGF] = { XHG_AG, XFS_SICK_AG_AGF },
87 [XFS_SCRUB_TYPE_AGFL] = { XHG_AG, XFS_SICK_AG_AGFL },
88 [XFS_SCRUB_TYPE_AGI] = { XHG_AG, XFS_SICK_AG_AGI },
89 [XFS_SCRUB_TYPE_BNOBT] = { XHG_AG, XFS_SICK_AG_BNOBT },
90 [XFS_SCRUB_TYPE_CNTBT] = { XHG_AG, XFS_SICK_AG_CNTBT },
91 [XFS_SCRUB_TYPE_INOBT] = { XHG_AG, XFS_SICK_AG_INOBT },
92 [XFS_SCRUB_TYPE_FINOBT] = { XHG_AG, XFS_SICK_AG_FINOBT },
93 [XFS_SCRUB_TYPE_RMAPBT] = { XHG_AG, XFS_SICK_AG_RMAPBT },
94 [XFS_SCRUB_TYPE_REFCNTBT] = { XHG_AG, XFS_SICK_AG_REFCNTBT },
95 [XFS_SCRUB_TYPE_INODE] = { XHG_INO, XFS_SICK_INO_CORE },
96 [XFS_SCRUB_TYPE_BMBTD] = { XHG_INO, XFS_SICK_INO_BMBTD },
97 [XFS_SCRUB_TYPE_BMBTA] = { XHG_INO, XFS_SICK_INO_BMBTA },
98 [XFS_SCRUB_TYPE_BMBTC] = { XHG_INO, XFS_SICK_INO_BMBTC },
99 [XFS_SCRUB_TYPE_DIR] = { XHG_INO, XFS_SICK_INO_DIR },
100 [XFS_SCRUB_TYPE_XATTR] = { XHG_INO, XFS_SICK_INO_XATTR },
101 [XFS_SCRUB_TYPE_SYMLINK] = { XHG_INO, XFS_SICK_INO_SYMLINK },
102 [XFS_SCRUB_TYPE_PARENT] = { XHG_INO, XFS_SICK_INO_PARENT },
103 [XFS_SCRUB_TYPE_RTBITMAP] = { XHG_RT, XFS_SICK_RT_BITMAP },
104 [XFS_SCRUB_TYPE_RTSUM] = { XHG_RT, XFS_SICK_RT_SUMMARY },
105 [XFS_SCRUB_TYPE_UQUOTA] = { XHG_FS, XFS_SICK_FS_UQUOTA },
106 [XFS_SCRUB_TYPE_GQUOTA] = { XHG_FS, XFS_SICK_FS_GQUOTA },
107 [XFS_SCRUB_TYPE_PQUOTA] = { XHG_FS, XFS_SICK_FS_PQUOTA },
108 [XFS_SCRUB_TYPE_FSCOUNTERS] = { XHG_FS, XFS_SICK_FS_COUNTERS },
109 [XFS_SCRUB_TYPE_QUOTACHECK] = { XHG_FS, XFS_SICK_FS_QUOTACHECK },
110 [XFS_SCRUB_TYPE_NLINKS] = { XHG_FS, XFS_SICK_FS_NLINKS },
111 [XFS_SCRUB_TYPE_DIRTREE] = { XHG_INO, XFS_SICK_INO_DIRTREE },
112 };
113
114 /* Return the health status mask for this scrub type. */
115 unsigned int
116 xchk_health_mask_for_scrub_type(
117 __u32 scrub_type)
118 {
119 return type_to_health_flag[scrub_type].sick_mask;
120 }
121
122 /*
123 * If the scrub state is clean, add @mask to the scrub sick mask to clear
124 * additional sick flags from the metadata object's sick state.
125 */
126 void
127 xchk_mark_healthy_if_clean(
128 struct xfs_scrub *sc,
129 unsigned int mask)
130 {
131 if (!(sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
132 XFS_SCRUB_OFLAG_XCORRUPT)))
133 sc->sick_mask |= mask;
134 }
135
136 /*
137 * If we're scrubbing a piece of file metadata for the first time, does it look
138 * like it has been zapped? Skip the check if we just repaired the metadata
139 * and are revalidating it.
140 */
141 bool
142 xchk_file_looks_zapped(
143 struct xfs_scrub *sc,
144 unsigned int mask)
145 {
146 ASSERT((mask & ~XFS_SICK_INO_ZAPPED) == 0);
147
148 if (sc->flags & XREP_ALREADY_FIXED)
149 return false;
150
151 return xfs_inode_has_sickness(sc->ip, mask);
152 }
153
154 /*
155 * Scrub gave the filesystem a clean bill of health, so clear all the indirect
156 * markers of past problems (at least for the fs and ags) so that we can be
157 * healthy again.
158 */
159 STATIC void
160 xchk_mark_all_healthy(
161 struct xfs_mount *mp)
162 {
163 struct xfs_perag *pag;
164 xfs_agnumber_t agno;
165
166 xfs_fs_mark_healthy(mp, XFS_SICK_FS_INDIRECT);
167 xfs_rt_mark_healthy(mp, XFS_SICK_RT_INDIRECT);
168 for_each_perag(mp, agno, pag)
169 xfs_ag_mark_healthy(pag, XFS_SICK_AG_INDIRECT);
170 }
171
172 /*
173 * Update filesystem health assessments based on what we found and did.
174 *
175 * If the scrubber finds errors, we mark sick whatever's mentioned in
176 * sick_mask, no matter whether this is a first scan or an
177 * evaluation of repair effectiveness.
178 *
179 * Otherwise, no direct corruption was found, so mark whatever's in
180 * sick_mask as healthy.
181 */
182 void
183 xchk_update_health(
184 struct xfs_scrub *sc)
185 {
186 struct xfs_perag *pag;
187 bool bad;
188
189 /*
190 * The HEALTHY scrub type is a request from userspace to clear all the
191 * indirect flags after a clean scan of the entire filesystem. As such
192 * there's no sick flag defined for it, so we branch here ahead of the
193 * mask check.
194 */
195 if (sc->sm->sm_type == XFS_SCRUB_TYPE_HEALTHY &&
196 !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
197 xchk_mark_all_healthy(sc->mp);
198 return;
199 }
200
201 if (!sc->sick_mask)
202 return;
203
204 bad = (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
205 XFS_SCRUB_OFLAG_XCORRUPT));
206 switch (type_to_health_flag[sc->sm->sm_type].group) {
207 case XHG_AG:
208 pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
209 if (bad)
210 xfs_ag_mark_corrupt(pag, sc->sick_mask);
211 else
212 xfs_ag_mark_healthy(pag, sc->sick_mask);
213 xfs_perag_put(pag);
214 break;
215 case XHG_INO:
216 if (!sc->ip)
217 return;
218 if (bad) {
219 unsigned int mask = sc->sick_mask;
220
221 /*
222 * If we're coming in for repairs then we don't want
223 * sickness flags to propagate to the incore health
224 * status if the inode gets inactivated before we can
225 * fix it.
226 */
227 if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
228 mask |= XFS_SICK_INO_FORGET;
229 xfs_inode_mark_corrupt(sc->ip, mask);
230 } else
231 xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
232 break;
233 case XHG_FS:
234 if (bad)
235 xfs_fs_mark_corrupt(sc->mp, sc->sick_mask);
236 else
237 xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
238 break;
239 case XHG_RT:
240 if (bad)
241 xfs_rt_mark_corrupt(sc->mp, sc->sick_mask);
242 else
243 xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
244 break;
245 default:
246 ASSERT(0);
247 break;
248 }
249 }
250
251 /* Is the given per-AG btree healthy enough for scanning? */
252 void
253 xchk_ag_btree_del_cursor_if_sick(
254 struct xfs_scrub *sc,
255 struct xfs_btree_cur **curp,
256 unsigned int sm_type)
257 {
258 unsigned int mask = (*curp)->bc_ops->sick_mask;
259
260 /*
261 * We always want the cursor if it's the same type as whatever we're
262 * scrubbing, even if we already know the structure is corrupt.
263 *
264 * Otherwise, we're only interested in the btree for cross-referencing.
265 * If we know the btree is bad then don't bother, just set XFAIL.
266 */
267 if (sc->sm->sm_type == sm_type)
268 return;
269
270 /*
271 * If we just repaired some AG metadata, sc->sick_mask will reflect all
272 * the per-AG metadata types that were repaired. Exclude these from
273 * the filesystem health query because we have not yet updated the
274 * health status and we want everything to be scanned.
275 */
276 if ((sc->flags & XREP_ALREADY_FIXED) &&
277 type_to_health_flag[sc->sm->sm_type].group == XHG_AG)
278 mask &= ~sc->sick_mask;
279
280 if (xfs_ag_has_sickness((*curp)->bc_ag.pag, mask)) {
281 sc->sm->sm_flags |= XFS_SCRUB_OFLAG_XFAIL;
282 xfs_btree_del_cursor(*curp, XFS_BTREE_NOERROR);
283 *curp = NULL;
284 }
285 }
286
287 /*
288 * Quick scan to double-check that there isn't any evidence of lingering
289 * primary health problems. If we're still clear, then the health update will
290 * take care of clearing the indirect evidence.
291 */
292 int
293 xchk_health_record(
294 struct xfs_scrub *sc)
295 {
296 struct xfs_mount *mp = sc->mp;
297 struct xfs_perag *pag;
298 xfs_agnumber_t agno;
299
300 unsigned int sick;
301 unsigned int checked;
302
303 xfs_fs_measure_sickness(mp, &sick, &checked);
304 if (sick & XFS_SICK_FS_PRIMARY)
305 xchk_set_corrupt(sc);
306
307 xfs_rt_measure_sickness(mp, &sick, &checked);
308 if (sick & XFS_SICK_RT_PRIMARY)
309 xchk_set_corrupt(sc);
310
311 for_each_perag(mp, agno, pag) {
312 xfs_ag_measure_sickness(pag, &sick, &checked);
313 if (sick & XFS_SICK_AG_PRIMARY)
314 xchk_set_corrupt(sc);
315 }
316
317 return 0;
318 }
319
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