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
 68enum xchk_health_group {
 69	XHG_FS = 1,
 70	XHG_RT,
 71	XHG_AG,
 72	XHG_INO,
 73};
 74
 75struct xchk_health_map {
 76	enum xchk_health_group	group;
 77	unsigned int		sick_mask;
 78};
 79
 80static 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. */
108unsigned int
109xchk_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 */
125void
126xchk_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? */
172bool
173xchk_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}