xref: /linux/fs/xfs/scrub/health.c (revision 63b47f026cc841bd3d3438dd6fccbc394dfead87)
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