xref: /openbmc/linux/fs/xfs/scrub/health.c (revision 6c33a6f4)
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 #include "scrub/health.h"
15 
16 /*
17  * Scrub and In-Core Filesystem Health Assessments
18  * ===============================================
19  *
20  * Online scrub and repair have the time and the ability to perform stronger
21  * checks than we can do from the metadata verifiers, because they can
22  * cross-reference records between data structures.  Therefore, scrub is in a
23  * good position to update the online filesystem health assessments to reflect
24  * the good/bad state of the data structure.
25  *
26  * We therefore extend scrub in the following ways to achieve this:
27  *
28  * 1. Create a "sick_mask" field in the scrub context.  When we're setting up a
29  * scrub call, set this to the default XFS_SICK_* flag(s) for the selected
30  * scrub type (call it A).  Scrub and repair functions can override the default
31  * sick_mask value if they choose.
32  *
33  * 2. If the scrubber returns a runtime error code, we exit making no changes
34  * to the incore sick state.
35  *
36  * 3. If the scrubber finds that A is clean, use sick_mask to clear the incore
37  * sick flags before exiting.
38  *
39  * 4. If the scrubber finds that A is corrupt, use sick_mask to set the incore
40  * sick flags.  If the user didn't want to repair then we exit, leaving the
41  * metadata structure unfixed and the sick flag set.
42  *
43  * 5. Now we know that A is corrupt and the user wants to repair, so run the
44  * repairer.  If the repairer returns an error code, we exit with that error
45  * code, having made no further changes to the incore sick state.
46  *
47  * 6. If repair rebuilds A correctly and the subsequent re-scrub of A is clean,
48  * use sick_mask to clear the incore sick flags.  This should have the effect
49  * that A is no longer marked sick.
50  *
51  * 7. If repair rebuilds A incorrectly, the re-scrub will find it corrupt and
52  * use sick_mask to set the incore sick flags.  This should have no externally
53  * visible effect since we already set them in step (4).
54  *
55  * There are some complications to this story, however.  For certain types of
56  * complementary metadata indices (e.g. inobt/finobt), it is easier to rebuild
57  * both structures at the same time.  The following principles apply to this
58  * type of repair strategy:
59  *
60  * 8. Any repair function that rebuilds multiple structures should update
61  * sick_mask_visible to reflect whatever other structures are rebuilt, and
62  * verify that all the rebuilt structures can pass a scrub check.  The outcomes
63  * of 5-7 still apply, but with a sick_mask that covers everything being
64  * rebuilt.
65  */
66 
67 /* Map our scrub type to a sick mask and a set of health update functions. */
68 
69 enum xchk_health_group {
70 	XHG_FS = 1,
71 	XHG_RT,
72 	XHG_AG,
73 	XHG_INO,
74 };
75 
76 struct xchk_health_map {
77 	enum xchk_health_group	group;
78 	unsigned int		sick_mask;
79 };
80 
81 static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = {
82 	[XFS_SCRUB_TYPE_SB]		= { XHG_AG,  XFS_SICK_AG_SB },
83 	[XFS_SCRUB_TYPE_AGF]		= { XHG_AG,  XFS_SICK_AG_AGF },
84 	[XFS_SCRUB_TYPE_AGFL]		= { XHG_AG,  XFS_SICK_AG_AGFL },
85 	[XFS_SCRUB_TYPE_AGI]		= { XHG_AG,  XFS_SICK_AG_AGI },
86 	[XFS_SCRUB_TYPE_BNOBT]		= { XHG_AG,  XFS_SICK_AG_BNOBT },
87 	[XFS_SCRUB_TYPE_CNTBT]		= { XHG_AG,  XFS_SICK_AG_CNTBT },
88 	[XFS_SCRUB_TYPE_INOBT]		= { XHG_AG,  XFS_SICK_AG_INOBT },
89 	[XFS_SCRUB_TYPE_FINOBT]		= { XHG_AG,  XFS_SICK_AG_FINOBT },
90 	[XFS_SCRUB_TYPE_RMAPBT]		= { XHG_AG,  XFS_SICK_AG_RMAPBT },
91 	[XFS_SCRUB_TYPE_REFCNTBT]	= { XHG_AG,  XFS_SICK_AG_REFCNTBT },
92 	[XFS_SCRUB_TYPE_INODE]		= { XHG_INO, XFS_SICK_INO_CORE },
93 	[XFS_SCRUB_TYPE_BMBTD]		= { XHG_INO, XFS_SICK_INO_BMBTD },
94 	[XFS_SCRUB_TYPE_BMBTA]		= { XHG_INO, XFS_SICK_INO_BMBTA },
95 	[XFS_SCRUB_TYPE_BMBTC]		= { XHG_INO, XFS_SICK_INO_BMBTC },
96 	[XFS_SCRUB_TYPE_DIR]		= { XHG_INO, XFS_SICK_INO_DIR },
97 	[XFS_SCRUB_TYPE_XATTR]		= { XHG_INO, XFS_SICK_INO_XATTR },
98 	[XFS_SCRUB_TYPE_SYMLINK]	= { XHG_INO, XFS_SICK_INO_SYMLINK },
99 	[XFS_SCRUB_TYPE_PARENT]		= { XHG_INO, XFS_SICK_INO_PARENT },
100 	[XFS_SCRUB_TYPE_RTBITMAP]	= { XHG_RT,  XFS_SICK_RT_BITMAP },
101 	[XFS_SCRUB_TYPE_RTSUM]		= { XHG_RT,  XFS_SICK_RT_SUMMARY },
102 	[XFS_SCRUB_TYPE_UQUOTA]		= { XHG_FS,  XFS_SICK_FS_UQUOTA },
103 	[XFS_SCRUB_TYPE_GQUOTA]		= { XHG_FS,  XFS_SICK_FS_GQUOTA },
104 	[XFS_SCRUB_TYPE_PQUOTA]		= { XHG_FS,  XFS_SICK_FS_PQUOTA },
105 	[XFS_SCRUB_TYPE_FSCOUNTERS]	= { XHG_FS,  XFS_SICK_FS_COUNTERS },
106 };
107 
108 /* Return the health status mask for this scrub type. */
109 unsigned int
110 xchk_health_mask_for_scrub_type(
111 	__u32			scrub_type)
112 {
113 	return type_to_health_flag[scrub_type].sick_mask;
114 }
115 
116 /*
117  * Update filesystem health assessments based on what we found and did.
118  *
119  * If the scrubber finds errors, we mark sick whatever's mentioned in
120  * sick_mask, no matter whether this is a first scan or an
121  * evaluation of repair effectiveness.
122  *
123  * Otherwise, no direct corruption was found, so mark whatever's in
124  * sick_mask as healthy.
125  */
126 void
127 xchk_update_health(
128 	struct xfs_scrub	*sc)
129 {
130 	struct xfs_perag	*pag;
131 	bool			bad;
132 
133 	if (!sc->sick_mask)
134 		return;
135 
136 	bad = (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT);
137 	switch (type_to_health_flag[sc->sm->sm_type].group) {
138 	case XHG_AG:
139 		pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
140 		if (bad)
141 			xfs_ag_mark_sick(pag, sc->sick_mask);
142 		else
143 			xfs_ag_mark_healthy(pag, sc->sick_mask);
144 		xfs_perag_put(pag);
145 		break;
146 	case XHG_INO:
147 		if (!sc->ip)
148 			return;
149 		if (bad)
150 			xfs_inode_mark_sick(sc->ip, sc->sick_mask);
151 		else
152 			xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
153 		break;
154 	case XHG_FS:
155 		if (bad)
156 			xfs_fs_mark_sick(sc->mp, sc->sick_mask);
157 		else
158 			xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
159 		break;
160 	case XHG_RT:
161 		if (bad)
162 			xfs_rt_mark_sick(sc->mp, sc->sick_mask);
163 		else
164 			xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
165 		break;
166 	default:
167 		ASSERT(0);
168 		break;
169 	}
170 }
171 
172 /* Is the given per-AG btree healthy enough for scanning? */
173 bool
174 xchk_ag_btree_healthy_enough(
175 	struct xfs_scrub	*sc,
176 	struct xfs_perag	*pag,
177 	xfs_btnum_t		btnum)
178 {
179 	unsigned int		mask = 0;
180 
181 	/*
182 	 * We always want the cursor if it's the same type as whatever we're
183 	 * scrubbing, even if we already know the structure is corrupt.
184 	 *
185 	 * Otherwise, we're only interested in the btree for cross-referencing.
186 	 * If we know the btree is bad then don't bother, just set XFAIL.
187 	 */
188 	switch (btnum) {
189 	case XFS_BTNUM_BNO:
190 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_BNOBT)
191 			return true;
192 		mask = XFS_SICK_AG_BNOBT;
193 		break;
194 	case XFS_BTNUM_CNT:
195 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_CNTBT)
196 			return true;
197 		mask = XFS_SICK_AG_CNTBT;
198 		break;
199 	case XFS_BTNUM_INO:
200 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_INOBT)
201 			return true;
202 		mask = XFS_SICK_AG_INOBT;
203 		break;
204 	case XFS_BTNUM_FINO:
205 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_FINOBT)
206 			return true;
207 		mask = XFS_SICK_AG_FINOBT;
208 		break;
209 	case XFS_BTNUM_RMAP:
210 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_RMAPBT)
211 			return true;
212 		mask = XFS_SICK_AG_RMAPBT;
213 		break;
214 	case XFS_BTNUM_REFC:
215 		if (sc->sm->sm_type == XFS_SCRUB_TYPE_REFCNTBT)
216 			return true;
217 		mask = XFS_SICK_AG_REFCNTBT;
218 		break;
219 	default:
220 		ASSERT(0);
221 		return true;
222 	}
223 
224 	if (xfs_ag_has_sickness(pag, mask)) {
225 		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_XFAIL;
226 		return false;
227 	}
228 
229 	return true;
230 }
231