xref: /linux/fs/xfs/scrub/health.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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 };
112 
113 /* Return the health status mask for this scrub type. */
114 unsigned int
115 xchk_health_mask_for_scrub_type(
116 	__u32			scrub_type)
117 {
118 	return type_to_health_flag[scrub_type].sick_mask;
119 }
120 
121 /*
122  * If the scrub state is clean, add @mask to the scrub sick mask to clear
123  * additional sick flags from the metadata object's sick state.
124  */
125 void
126 xchk_mark_healthy_if_clean(
127 	struct xfs_scrub	*sc,
128 	unsigned int		mask)
129 {
130 	if (!(sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
131 				  XFS_SCRUB_OFLAG_XCORRUPT)))
132 		sc->sick_mask |= mask;
133 }
134 
135 /*
136  * If we're scrubbing a piece of file metadata for the first time, does it look
137  * like it has been zapped?  Skip the check if we just repaired the metadata
138  * and are revalidating it.
139  */
140 bool
141 xchk_file_looks_zapped(
142 	struct xfs_scrub	*sc,
143 	unsigned int		mask)
144 {
145 	ASSERT((mask & ~XFS_SICK_INO_ZAPPED) == 0);
146 
147 	if (sc->flags & XREP_ALREADY_FIXED)
148 		return false;
149 
150 	return xfs_inode_has_sickness(sc->ip, mask);
151 }
152 
153 /*
154  * Scrub gave the filesystem a clean bill of health, so clear all the indirect
155  * markers of past problems (at least for the fs and ags) so that we can be
156  * healthy again.
157  */
158 STATIC void
159 xchk_mark_all_healthy(
160 	struct xfs_mount	*mp)
161 {
162 	struct xfs_perag	*pag;
163 	xfs_agnumber_t		agno;
164 
165 	xfs_fs_mark_healthy(mp, XFS_SICK_FS_INDIRECT);
166 	xfs_rt_mark_healthy(mp, XFS_SICK_RT_INDIRECT);
167 	for_each_perag(mp, agno, pag)
168 		xfs_ag_mark_healthy(pag, XFS_SICK_AG_INDIRECT);
169 }
170 
171 /*
172  * Update filesystem health assessments based on what we found and did.
173  *
174  * If the scrubber finds errors, we mark sick whatever's mentioned in
175  * sick_mask, no matter whether this is a first scan or an
176  * evaluation of repair effectiveness.
177  *
178  * Otherwise, no direct corruption was found, so mark whatever's in
179  * sick_mask as healthy.
180  */
181 void
182 xchk_update_health(
183 	struct xfs_scrub	*sc)
184 {
185 	struct xfs_perag	*pag;
186 	bool			bad;
187 
188 	/*
189 	 * The HEALTHY scrub type is a request from userspace to clear all the
190 	 * indirect flags after a clean scan of the entire filesystem.  As such
191 	 * there's no sick flag defined for it, so we branch here ahead of the
192 	 * mask check.
193 	 */
194 	if (sc->sm->sm_type == XFS_SCRUB_TYPE_HEALTHY &&
195 	    !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
196 		xchk_mark_all_healthy(sc->mp);
197 		return;
198 	}
199 
200 	if (!sc->sick_mask)
201 		return;
202 
203 	bad = (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
204 				   XFS_SCRUB_OFLAG_XCORRUPT));
205 	switch (type_to_health_flag[sc->sm->sm_type].group) {
206 	case XHG_AG:
207 		pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
208 		if (bad)
209 			xfs_ag_mark_corrupt(pag, sc->sick_mask);
210 		else
211 			xfs_ag_mark_healthy(pag, sc->sick_mask);
212 		xfs_perag_put(pag);
213 		break;
214 	case XHG_INO:
215 		if (!sc->ip)
216 			return;
217 		if (bad) {
218 			unsigned int	mask = sc->sick_mask;
219 
220 			/*
221 			 * If we're coming in for repairs then we don't want
222 			 * sickness flags to propagate to the incore health
223 			 * status if the inode gets inactivated before we can
224 			 * fix it.
225 			 */
226 			if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
227 				mask |= XFS_SICK_INO_FORGET;
228 			xfs_inode_mark_corrupt(sc->ip, mask);
229 		} else
230 			xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
231 		break;
232 	case XHG_FS:
233 		if (bad)
234 			xfs_fs_mark_corrupt(sc->mp, sc->sick_mask);
235 		else
236 			xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
237 		break;
238 	case XHG_RT:
239 		if (bad)
240 			xfs_rt_mark_corrupt(sc->mp, sc->sick_mask);
241 		else
242 			xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
243 		break;
244 	default:
245 		ASSERT(0);
246 		break;
247 	}
248 }
249 
250 /* Is the given per-AG btree healthy enough for scanning? */
251 void
252 xchk_ag_btree_del_cursor_if_sick(
253 	struct xfs_scrub	*sc,
254 	struct xfs_btree_cur	**curp,
255 	unsigned int		sm_type)
256 {
257 	unsigned int		mask = (*curp)->bc_ops->sick_mask;
258 
259 	/*
260 	 * We always want the cursor if it's the same type as whatever we're
261 	 * scrubbing, even if we already know the structure is corrupt.
262 	 *
263 	 * Otherwise, we're only interested in the btree for cross-referencing.
264 	 * If we know the btree is bad then don't bother, just set XFAIL.
265 	 */
266 	if (sc->sm->sm_type == sm_type)
267 		return;
268 
269 	/*
270 	 * If we just repaired some AG metadata, sc->sick_mask will reflect all
271 	 * the per-AG metadata types that were repaired.  Exclude these from
272 	 * the filesystem health query because we have not yet updated the
273 	 * health status and we want everything to be scanned.
274 	 */
275 	if ((sc->flags & XREP_ALREADY_FIXED) &&
276 	    type_to_health_flag[sc->sm->sm_type].group == XHG_AG)
277 		mask &= ~sc->sick_mask;
278 
279 	if (xfs_ag_has_sickness((*curp)->bc_ag.pag, mask)) {
280 		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_XFAIL;
281 		xfs_btree_del_cursor(*curp, XFS_BTREE_NOERROR);
282 		*curp = NULL;
283 	}
284 }
285 
286 /*
287  * Quick scan to double-check that there isn't any evidence of lingering
288  * primary health problems.  If we're still clear, then the health update will
289  * take care of clearing the indirect evidence.
290  */
291 int
292 xchk_health_record(
293 	struct xfs_scrub	*sc)
294 {
295 	struct xfs_mount	*mp = sc->mp;
296 	struct xfs_perag	*pag;
297 	xfs_agnumber_t		agno;
298 
299 	unsigned int		sick;
300 	unsigned int		checked;
301 
302 	xfs_fs_measure_sickness(mp, &sick, &checked);
303 	if (sick & XFS_SICK_FS_PRIMARY)
304 		xchk_set_corrupt(sc);
305 
306 	xfs_rt_measure_sickness(mp, &sick, &checked);
307 	if (sick & XFS_SICK_RT_PRIMARY)
308 		xchk_set_corrupt(sc);
309 
310 	for_each_perag(mp, agno, pag) {
311 		xfs_ag_measure_sickness(pag, &sick, &checked);
312 		if (sick & XFS_SICK_AG_PRIMARY)
313 			xchk_set_corrupt(sc);
314 	}
315 
316 	return 0;
317 }
318