1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2020-2023 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_log_format.h"
14#include "xfs_trans.h"
15#include "xfs_inode.h"
16#include "xfs_bit.h"
17#include "xfs_bmap.h"
18#include "xfs_bmap_btree.h"
19#include "scrub/scrub.h"
20#include "scrub/common.h"
21#include "scrub/trace.h"
22#include "scrub/repair.h"
23#include "scrub/xfile.h"
24#include "scrub/rtbitmap.h"
25
26/* Set up to repair the realtime bitmap file metadata. */
27int
28xrep_setup_rtbitmap(
29	struct xfs_scrub	*sc,
30	struct xchk_rtbitmap	*rtb)
31{
32	struct xfs_mount	*mp = sc->mp;
33	unsigned long long	blocks = 0;
34
35	/*
36	 * Reserve enough blocks to write out a completely new bmbt for a
37	 * maximally fragmented bitmap file.  We do not hold the rtbitmap
38	 * ILOCK yet, so this is entirely speculative.
39	 */
40	blocks = xfs_bmbt_calc_size(mp, mp->m_sb.sb_rbmblocks);
41	if (blocks > UINT_MAX)
42		return -EOPNOTSUPP;
43
44	rtb->resblks += blocks;
45	return 0;
46}
47
48/*
49 * Make sure that the given range of the data fork of the realtime file is
50 * mapped to written blocks.  The caller must ensure that the inode is joined
51 * to the transaction.
52 */
53STATIC int
54xrep_rtbitmap_data_mappings(
55	struct xfs_scrub	*sc,
56	xfs_filblks_t		len)
57{
58	struct xfs_bmbt_irec	map;
59	xfs_fileoff_t		off = 0;
60	int			error;
61
62	ASSERT(sc->ip != NULL);
63
64	while (off < len) {
65		int		nmaps = 1;
66
67		/*
68		 * If we have a real extent mapping this block then we're
69		 * in ok shape.
70		 */
71		error = xfs_bmapi_read(sc->ip, off, len - off, &map, &nmaps,
72				XFS_DATA_FORK);
73		if (error)
74			return error;
75		if (nmaps == 0) {
76			ASSERT(nmaps != 0);
77			return -EFSCORRUPTED;
78		}
79
80		/*
81		 * Written extents are ok.  Holes are not filled because we
82		 * do not know the freespace information.
83		 */
84		if (xfs_bmap_is_written_extent(&map) ||
85		    map.br_startblock == HOLESTARTBLOCK) {
86			off = map.br_startoff + map.br_blockcount;
87			continue;
88		}
89
90		/*
91		 * If we find a delalloc reservation then something is very
92		 * very wrong.  Bail out.
93		 */
94		if (map.br_startblock == DELAYSTARTBLOCK)
95			return -EFSCORRUPTED;
96
97		/* Make sure we're really converting an unwritten extent. */
98		if (map.br_state != XFS_EXT_UNWRITTEN) {
99			ASSERT(map.br_state == XFS_EXT_UNWRITTEN);
100			return -EFSCORRUPTED;
101		}
102
103		/* Make sure this block has a real zeroed extent mapped. */
104		nmaps = 1;
105		error = xfs_bmapi_write(sc->tp, sc->ip, map.br_startoff,
106				map.br_blockcount,
107				XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO,
108				0, &map, &nmaps);
109		if (error)
110			return error;
111		if (nmaps != 1)
112			return -EFSCORRUPTED;
113
114		/* Commit new extent and all deferred work. */
115		error = xrep_defer_finish(sc);
116		if (error)
117			return error;
118
119		off = map.br_startoff + map.br_blockcount;
120	}
121
122	return 0;
123}
124
125/* Fix broken rt volume geometry. */
126STATIC int
127xrep_rtbitmap_geometry(
128	struct xfs_scrub	*sc,
129	struct xchk_rtbitmap	*rtb)
130{
131	struct xfs_mount	*mp = sc->mp;
132	struct xfs_trans	*tp = sc->tp;
133
134	/* Superblock fields */
135	if (mp->m_sb.sb_rextents != rtb->rextents)
136		xfs_trans_mod_sb(sc->tp, XFS_TRANS_SB_REXTENTS,
137				rtb->rextents - mp->m_sb.sb_rextents);
138
139	if (mp->m_sb.sb_rbmblocks != rtb->rbmblocks)
140		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
141				rtb->rbmblocks - mp->m_sb.sb_rbmblocks);
142
143	if (mp->m_sb.sb_rextslog != rtb->rextslog)
144		xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
145				rtb->rextslog - mp->m_sb.sb_rextslog);
146
147	/* Fix broken isize */
148	sc->ip->i_disk_size = roundup_64(sc->ip->i_disk_size,
149					 mp->m_sb.sb_blocksize);
150
151	if (sc->ip->i_disk_size < XFS_FSB_TO_B(mp, rtb->rbmblocks))
152		sc->ip->i_disk_size = XFS_FSB_TO_B(mp, rtb->rbmblocks);
153
154	xfs_trans_log_inode(sc->tp, sc->ip, XFS_ILOG_CORE);
155	return xrep_roll_trans(sc);
156}
157
158/* Repair the realtime bitmap file metadata. */
159int
160xrep_rtbitmap(
161	struct xfs_scrub	*sc)
162{
163	struct xchk_rtbitmap	*rtb = sc->buf;
164	struct xfs_mount	*mp = sc->mp;
165	unsigned long long	blocks = 0;
166	int			error;
167
168	/* Impossibly large rtbitmap means we can't touch the filesystem. */
169	if (rtb->rbmblocks > U32_MAX)
170		return 0;
171
172	/*
173	 * If the size of the rt bitmap file is larger than what we reserved,
174	 * figure out if we need to adjust the block reservation in the
175	 * transaction.
176	 */
177	blocks = xfs_bmbt_calc_size(mp, rtb->rbmblocks);
178	if (blocks > UINT_MAX)
179		return -EOPNOTSUPP;
180	if (blocks > rtb->resblks) {
181		error = xfs_trans_reserve_more(sc->tp, blocks, 0);
182		if (error)
183			return error;
184
185		rtb->resblks += blocks;
186	}
187
188	/* Fix inode core and forks. */
189	error = xrep_metadata_inode_forks(sc);
190	if (error)
191		return error;
192
193	xfs_trans_ijoin(sc->tp, sc->ip, 0);
194
195	/* Ensure no unwritten extents. */
196	error = xrep_rtbitmap_data_mappings(sc, rtb->rbmblocks);
197	if (error)
198		return error;
199
200	/* Fix inconsistent bitmap geometry */
201	return xrep_rtbitmap_geometry(sc, rtb);
202}
203