xref: /linux/fs/xfs/scrub/health.c (revision 3f61fd41f38328f0a585eaba2d72d339fe9aecda)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019 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_btree.h"
11 #include "xfs_sb.h"
12 #include "xfs_health.h"
13 #include "scrub/scrub.h"
14 
15 /*
16  * Scrub and In-Core Filesystem Health Assessments
17  * ===============================================
18  *
19  * Online scrub and repair have the time and the ability to perform stronger
20  * checks than we can do from the metadata verifiers, because they can
21  * cross-reference records between data structures.  Therefore, scrub is in a
22  * good position to update the online filesystem health assessments to reflect
23  * the good/bad state of the data structure.
24  *
25  * We therefore extend scrub in the following ways to achieve this:
26  *
27  * 1. Create a "sick_mask" field in the scrub context.  When we're setting up a
28  * scrub call, set this to the default XFS_SICK_* flag(s) for the selected
29  * scrub type (call it A).  Scrub and repair functions can override the default
30  * sick_mask value if they choose.
31  *
32  * 2. If the scrubber returns a runtime error code, we exit making no changes
33  * to the incore sick state.
34  *
35  * 3. If the scrubber finds that A is clean, use sick_mask to clear the incore
36  * sick flags before exiting.
37  *
38  * 4. If the scrubber finds that A is corrupt, use sick_mask to set the incore
39  * sick flags.  If the user didn't want to repair then we exit, leaving the
40  * metadata structure unfixed and the sick flag set.
41  *
42  * 5. Now we know that A is corrupt and the user wants to repair, so run the
43  * repairer.  If the repairer returns an error code, we exit with that error
44  * code, having made no further changes to the incore sick state.
45  *
46  * 6. If repair rebuilds A correctly and the subsequent re-scrub of A is clean,
47  * use sick_mask to clear the incore sick flags.  This should have the effect
48  * that A is no longer marked sick.
49  *
50  * 7. If repair rebuilds A incorrectly, the re-scrub will find it corrupt and
51  * use sick_mask to set the incore sick flags.  This should have no externally
52  * visible effect since we already set them in step (4).
53  *
54  * There are some complications to this story, however.  For certain types of
55  * complementary metadata indices (e.g. inobt/finobt), it is easier to rebuild
56  * both structures at the same time.  The following principles apply to this
57  * type of repair strategy:
58  *
59  * 8. Any repair function that rebuilds multiple structures should update
60  * sick_mask_visible to reflect whatever other structures are rebuilt, and
61  * verify that all the rebuilt structures can pass a scrub check.  The outcomes
62  * of 5-7 still apply, but with a sick_mask that covers everything being
63  * rebuilt.
64  */
65 
66 /* Map our scrub type to a sick mask and a set of health update functions. */
67 
68 enum xchk_health_group {
69 	XHG_FS = 1,
70 	XHG_RT,
71 	XHG_AG,
72 	XHG_INO,
73 };
74 
75 struct xchk_health_map {
76 	enum xchk_health_group	group;
77 	unsigned int		sick_mask;
78 };
79 
80 static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = {
81 	[XFS_SCRUB_TYPE_SB]		= { XHG_AG,  XFS_SICK_AG_SB },
82 	[XFS_SCRUB_TYPE_AGF]		= { XHG_AG,  XFS_SICK_AG_AGF },
83 	[XFS_SCRUB_TYPE_AGFL]		= { XHG_AG,  XFS_SICK_AG_AGFL },
84 	[XFS_SCRUB_TYPE_AGI]		= { XHG_AG,  XFS_SICK_AG_AGI },
85 	[XFS_SCRUB_TYPE_BNOBT]		= { XHG_AG,  XFS_SICK_AG_BNOBT },
86 	[XFS_SCRUB_TYPE_CNTBT]		= { XHG_AG,  XFS_SICK_AG_CNTBT },
87 	[XFS_SCRUB_TYPE_INOBT]		= { XHG_AG,  XFS_SICK_AG_INOBT },
88 	[XFS_SCRUB_TYPE_FINOBT]		= { XHG_AG,  XFS_SICK_AG_FINOBT },
89 	[XFS_SCRUB_TYPE_RMAPBT]		= { XHG_AG,  XFS_SICK_AG_RMAPBT },
90 	[XFS_SCRUB_TYPE_REFCNTBT]	= { XHG_AG,  XFS_SICK_AG_REFCNTBT },
91 	[XFS_SCRUB_TYPE_INODE]		= { XHG_INO, XFS_SICK_INO_CORE },
92 	[XFS_SCRUB_TYPE_BMBTD]		= { XHG_INO, XFS_SICK_INO_BMBTD },
93 	[XFS_SCRUB_TYPE_BMBTA]		= { XHG_INO, XFS_SICK_INO_BMBTA },
94 	[XFS_SCRUB_TYPE_BMBTC]		= { XHG_INO, XFS_SICK_INO_BMBTC },
95 	[XFS_SCRUB_TYPE_DIR]		= { XHG_INO, XFS_SICK_INO_DIR },
96 	[XFS_SCRUB_TYPE_XATTR]		= { XHG_INO, XFS_SICK_INO_XATTR },
97 	[XFS_SCRUB_TYPE_SYMLINK]	= { XHG_INO, XFS_SICK_INO_SYMLINK },
98 	[XFS_SCRUB_TYPE_PARENT]		= { XHG_INO, XFS_SICK_INO_PARENT },
99 	[XFS_SCRUB_TYPE_RTBITMAP]	= { XHG_RT,  XFS_SICK_RT_BITMAP },
100 	[XFS_SCRUB_TYPE_RTSUM]		= { XHG_RT,  XFS_SICK_RT_SUMMARY },
101 	[XFS_SCRUB_TYPE_UQUOTA]		= { XHG_FS,  XFS_SICK_FS_UQUOTA },
102 	[XFS_SCRUB_TYPE_GQUOTA]		= { XHG_FS,  XFS_SICK_FS_GQUOTA },
103 	[XFS_SCRUB_TYPE_PQUOTA]		= { XHG_FS,  XFS_SICK_FS_PQUOTA },
104 	[XFS_SCRUB_TYPE_FSCOUNTERS]	= { XHG_FS,  XFS_SICK_FS_COUNTERS },
105 };
106 
107 /* Return the health status mask for this scrub type. */
108 unsigned int
109 xchk_health_mask_for_scrub_type(
110 	__u32			scrub_type)
111 {
112 	return type_to_health_flag[scrub_type].sick_mask;
113 }
114 
115 /*
116  * Update filesystem health assessments based on what we found and did.
117  *
118  * If the scrubber finds errors, we mark sick whatever's mentioned in
119  * sick_mask, no matter whether this is a first scan or an
120  * evaluation of repair effectiveness.
121  *
122  * Otherwise, no direct corruption was found, so mark whatever's in
123  * sick_mask as healthy.
124  */
125 void
126 xchk_update_health(
127 	struct xfs_scrub	*sc)
128 {
129 	struct xfs_perag	*pag;
130 	bool			bad;
131 
132 	if (!sc->sick_mask)
133 		return;
134 
135 	bad = (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT);
136 	switch (type_to_health_flag[sc->sm->sm_type].group) {
137 	case XHG_AG:
138 		pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
139 		if (bad)
140 			xfs_ag_mark_sick(pag, sc->sick_mask);
141 		else
142 			xfs_ag_mark_healthy(pag, sc->sick_mask);
143 		xfs_perag_put(pag);
144 		break;
145 	case XHG_INO:
146 		if (!sc->ip)
147 			return;
148 		if (bad)
149 			xfs_inode_mark_sick(sc->ip, sc->sick_mask);
150 		else
151 			xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
152 		break;
153 	case XHG_FS:
154 		if (bad)
155 			xfs_fs_mark_sick(sc->mp, sc->sick_mask);
156 		else
157 			xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
158 		break;
159 	case XHG_RT:
160 		if (bad)
161 			xfs_rt_mark_sick(sc->mp, sc->sick_mask);
162 		else
163 			xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
164 		break;
165 	default:
166 		ASSERT(0);
167 		break;
168 	}
169 }
170 
171 /* Is the given per-AG btree healthy enough for scanning? */
172 bool
173 xchk_ag_btree_healthy_enough(
174 	struct xfs_scrub	*sc,
175 	struct xfs_perag	*pag,
176 	xfs_btnum_t		btnum)
177 {
178 	unsigned int		mask = 0;
179 
180 	/*
181 	 * We always want the cursor if it's the same type as whatever we're
182 	 * scrubbing, even if we already know the structure is corrupt.
183 	 *
184 	 * Otherwise, we're only interested in the btree for cross-referencing.
185 	 * If we know the btree is bad then don't bother, just set XFAIL.
186 	 */
187 	switch (btnum) {
188 	case XFS_BTNUM_BNO:
189 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_BNOBT)
190 			return true;
191 		mask = XFS_SICK_AG_BNOBT;
192 		break;
193 	case XFS_BTNUM_CNT:
194 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_CNTBT)
195 			return true;
196 		mask = XFS_SICK_AG_CNTBT;
197 		break;
198 	case XFS_BTNUM_INO:
199 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_INOBT)
200 			return true;
201 		mask = XFS_SICK_AG_INOBT;
202 		break;
203 	case XFS_BTNUM_FINO:
204 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_FINOBT)
205 			return true;
206 		mask = XFS_SICK_AG_FINOBT;
207 		break;
208 	case XFS_BTNUM_RMAP:
209 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_RMAPBT)
210 			return true;
211 		mask = XFS_SICK_AG_RMAPBT;
212 		break;
213 	case XFS_BTNUM_REFC:
214 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_REFCNTBT)
215 			return true;
216 		mask = XFS_SICK_AG_REFCNTBT;
217 		break;
218 	default:
219 		ASSERT(0);
220 		return true;
221 	}
222 
223 	if (xfs_ag_has_sickness(pag, mask)) {
224 		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_XFAIL;
225 		return false;
226 	}
227 
228 	return true;
229 }
230