xref: /linux/fs/xfs/scrub/rtbitmap.c (revision d7b4e3287ca3a7baf66efd9158498e551a9550da)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2017-2023 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_log_format.h"
13 #include "xfs_trans.h"
14 #include "xfs_rtbitmap.h"
15 #include "xfs_inode.h"
16 #include "xfs_bmap.h"
17 #include "xfs_bit.h"
18 #include "xfs_sb.h"
19 #include "scrub/scrub.h"
20 #include "scrub/common.h"
21 #include "scrub/repair.h"
22 #include "scrub/rtbitmap.h"
23 
24 /* Set us up with the realtime metadata locked. */
25 int
26 xchk_setup_rtbitmap(
27 	struct xfs_scrub	*sc)
28 {
29 	struct xfs_mount	*mp = sc->mp;
30 	struct xchk_rtbitmap	*rtb;
31 	int			error;
32 
33 	rtb = kzalloc(sizeof(struct xchk_rtbitmap), XCHK_GFP_FLAGS);
34 	if (!rtb)
35 		return -ENOMEM;
36 	sc->buf = rtb;
37 
38 	if (xchk_could_repair(sc)) {
39 		error = xrep_setup_rtbitmap(sc, rtb);
40 		if (error)
41 			return error;
42 	}
43 
44 	error = xchk_trans_alloc(sc, rtb->resblks);
45 	if (error)
46 		return error;
47 
48 	error = xchk_install_live_inode(sc, sc->mp->m_rbmip);
49 	if (error)
50 		return error;
51 
52 	error = xchk_ino_dqattach(sc);
53 	if (error)
54 		return error;
55 
56 	xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP);
57 
58 	/*
59 	 * Now that we've locked the rtbitmap, we can't race with growfsrt
60 	 * trying to expand the bitmap or change the size of the rt volume.
61 	 * Hence it is safe to compute and check the geometry values.
62 	 */
63 	if (mp->m_sb.sb_rblocks) {
64 		rtb->rextents = xfs_rtb_to_rtx(mp, mp->m_sb.sb_rblocks);
65 		rtb->rextslog = xfs_compute_rextslog(rtb->rextents);
66 		rtb->rbmblocks = xfs_rtbitmap_blockcount(mp, rtb->rextents);
67 	}
68 	return 0;
69 }
70 
71 /* Realtime bitmap. */
72 
73 /* Scrub a free extent record from the realtime bitmap. */
74 STATIC int
75 xchk_rtbitmap_rec(
76 	struct xfs_mount	*mp,
77 	struct xfs_trans	*tp,
78 	const struct xfs_rtalloc_rec *rec,
79 	void			*priv)
80 {
81 	struct xfs_scrub	*sc = priv;
82 	xfs_rtblock_t		startblock;
83 	xfs_filblks_t		blockcount;
84 
85 	startblock = xfs_rtx_to_rtb(mp, rec->ar_startext);
86 	blockcount = xfs_rtx_to_rtb(mp, rec->ar_extcount);
87 
88 	if (!xfs_verify_rtbext(mp, startblock, blockcount))
89 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
90 	return 0;
91 }
92 
93 /* Make sure the entire rtbitmap file is mapped with written extents. */
94 STATIC int
95 xchk_rtbitmap_check_extents(
96 	struct xfs_scrub	*sc)
97 {
98 	struct xfs_bmbt_irec	map;
99 	struct xfs_iext_cursor	icur;
100 	struct xfs_mount	*mp = sc->mp;
101 	struct xfs_inode	*ip = sc->ip;
102 	xfs_fileoff_t		off = 0;
103 	xfs_fileoff_t		endoff;
104 	int			error = 0;
105 
106 	/* Mappings may not cross or lie beyond EOF. */
107 	endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);
108 	if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {
109 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);
110 		return 0;
111 	}
112 
113 	while (off < endoff) {
114 		int		nmap = 1;
115 
116 		if (xchk_should_terminate(sc, &error) ||
117 		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
118 			break;
119 
120 		/* Make sure we have a written extent. */
121 		error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,
122 				XFS_DATA_FORK);
123 		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
124 			break;
125 
126 		if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
127 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
128 			break;
129 		}
130 
131 		off += map.br_blockcount;
132 	}
133 
134 	return error;
135 }
136 
137 /* Scrub the realtime bitmap. */
138 int
139 xchk_rtbitmap(
140 	struct xfs_scrub	*sc)
141 {
142 	struct xfs_mount	*mp = sc->mp;
143 	struct xchk_rtbitmap	*rtb = sc->buf;
144 	int			error;
145 
146 	/* Is sb_rextents correct? */
147 	if (mp->m_sb.sb_rextents != rtb->rextents) {
148 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
149 		return 0;
150 	}
151 
152 	/* Is sb_rextslog correct? */
153 	if (mp->m_sb.sb_rextslog != rtb->rextslog) {
154 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
155 		return 0;
156 	}
157 
158 	/*
159 	 * Is sb_rbmblocks large enough to handle the current rt volume?  In no
160 	 * case can we exceed 4bn bitmap blocks since the super field is a u32.
161 	 */
162 	if (rtb->rbmblocks > U32_MAX) {
163 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
164 		return 0;
165 	}
166 	if (mp->m_sb.sb_rbmblocks != rtb->rbmblocks) {
167 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
168 		return 0;
169 	}
170 
171 	/* The bitmap file length must be aligned to an fsblock. */
172 	if (mp->m_rbmip->i_disk_size & mp->m_blockmask) {
173 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
174 		return 0;
175 	}
176 
177 	/*
178 	 * Is the bitmap file itself large enough to handle the rt volume?
179 	 * growfsrt expands the bitmap file before updating sb_rextents, so the
180 	 * file can be larger than sb_rbmblocks.
181 	 */
182 	if (mp->m_rbmip->i_disk_size < XFS_FSB_TO_B(mp, rtb->rbmblocks)) {
183 		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);
184 		return 0;
185 	}
186 
187 	/* Invoke the fork scrubber. */
188 	error = xchk_metadata_inode_forks(sc);
189 	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
190 		return error;
191 
192 	error = xchk_rtbitmap_check_extents(sc);
193 	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
194 		return error;
195 
196 	error = xfs_rtalloc_query_all(mp, sc->tp, xchk_rtbitmap_rec, sc);
197 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
198 		return error;
199 
200 	return 0;
201 }
202 
203 /* xref check that the extent is not free in the rtbitmap */
204 void
205 xchk_xref_is_used_rt_space(
206 	struct xfs_scrub	*sc,
207 	xfs_rtblock_t		rtbno,
208 	xfs_extlen_t		len)
209 {
210 	xfs_rtxnum_t		startext;
211 	xfs_rtxnum_t		endext;
212 	bool			is_free;
213 	int			error;
214 
215 	if (xchk_skip_xref(sc->sm))
216 		return;
217 
218 	startext = xfs_rtb_to_rtx(sc->mp, rtbno);
219 	endext = xfs_rtb_to_rtx(sc->mp, rtbno + len - 1);
220 	xfs_ilock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
221 	error = xfs_rtalloc_extent_is_free(sc->mp, sc->tp, startext,
222 			endext - startext + 1, &is_free);
223 	if (!xchk_should_check_xref(sc, &error, NULL))
224 		goto out_unlock;
225 	if (is_free)
226 		xchk_ino_xref_set_corrupt(sc, sc->mp->m_rbmip->i_ino);
227 out_unlock:
228 	xfs_iunlock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
229 }
230