Line data Source code
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_btree.h"
13 : #include "xfs_inode.h"
14 : #include "xfs_log_format.h"
15 : #include "xfs_trans.h"
16 : #include "xfs_rtalloc.h"
17 : #include "xfs_bit.h"
18 : #include "xfs_bmap.h"
19 : #include "scrub/scrub.h"
20 : #include "scrub/common.h"
21 : #include "scrub/trace.h"
22 : #include "scrub/xfile.h"
23 : #include "scrub/repair.h"
24 : #include "scrub/rtsummary.h"
25 :
26 : /*
27 : * Realtime Summary
28 : * ================
29 : *
30 : * We check the realtime summary by scanning the realtime bitmap file to create
31 : * a new summary file incore, and then we compare the computed version against
32 : * the ondisk version. We use the 'xfile' functionality to store this
33 : * (potentially large) amount of data in pageable memory.
34 : */
35 :
36 : /* Set us up to check the rtsummary file. */
37 : int
38 39792 : xchk_setup_rtsummary(
39 : struct xfs_scrub *sc)
40 : {
41 39792 : struct xfs_mount *mp = sc->mp;
42 39792 : char *descr;
43 39792 : size_t bufsize = mp->m_sb.sb_blocksize;
44 39792 : unsigned int resblks = 0;
45 39792 : int error;
46 :
47 79584 : if (xchk_could_repair(sc)) {
48 1764 : error = xrep_setup_rtsummary(sc, &resblks, &bufsize);
49 1764 : if (error)
50 : return error;
51 : }
52 :
53 : /*
54 : * Create an xfile to construct a new rtsummary file. The xfile allows
55 : * us to avoid pinning kernel memory for this purpose.
56 : */
57 38028 : descr = xchk_xfile_descr(sc, "realtime summary file");
58 38028 : error = xfile_create(descr, mp->m_rsumsize, &sc->xfile);
59 38028 : kfree(descr);
60 38028 : if (error)
61 : return error;
62 :
63 38028 : error = xchk_trans_alloc(sc, resblks);
64 38028 : if (error)
65 : return error;
66 :
67 : /* Allocate a memory buffer for the summary comparison. */
68 38028 : sc->buf = kvmalloc(bufsize, XCHK_GFP_FLAGS);
69 38028 : if (!sc->buf)
70 : return -ENOMEM;
71 :
72 38028 : error = xchk_install_live_inode(sc, mp->m_rsumip);
73 38028 : if (error)
74 : return error;
75 :
76 38028 : error = xchk_ino_dqattach(sc);
77 38028 : if (error)
78 : return error;
79 :
80 : /*
81 : * Locking order requires us to take the rtbitmap first. We must be
82 : * careful to unlock it ourselves when we are done with the rtbitmap
83 : * file since the scrub infrastructure won't do that for us. Only
84 : * then we can lock the rtsummary inode.
85 : */
86 38028 : xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
87 38028 : xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);
88 38028 : return 0;
89 : }
90 :
91 : /* Helper functions to record suminfo words in an xfile. */
92 :
93 : static inline int
94 : xfsum_load(
95 : struct xfs_scrub *sc,
96 : xchk_rtsumoff_t sumoff,
97 : xfs_suminfo_t *info)
98 : {
99 16643782 : return xfile_obj_load(sc->xfile, info, sizeof(xfs_suminfo_t),
100 16643782 : sumoff << XFS_WORDLOG);
101 : }
102 :
103 : static inline int
104 : xfsum_store(
105 : struct xfs_scrub *sc,
106 : xchk_rtsumoff_t sumoff,
107 : const xfs_suminfo_t info)
108 : {
109 16643782 : return xfile_obj_store(sc->xfile, &info, sizeof(xfs_suminfo_t),
110 : sumoff << XFS_WORDLOG);
111 : }
112 :
113 : inline int
114 0 : xfsum_copyout(
115 : struct xfs_scrub *sc,
116 : xchk_rtsumoff_t sumoff,
117 : xfs_suminfo_t *info,
118 : unsigned int nr_words)
119 : {
120 242007 : return xfile_obj_load(sc->xfile, info, nr_words << XFS_WORDLOG,
121 0 : sumoff << XFS_WORDLOG);
122 : }
123 :
124 : /* Update the summary file to reflect the free extent that we've accumulated. */
125 : STATIC int
126 16643782 : xchk_rtsum_record_free(
127 : struct xfs_mount *mp,
128 : struct xfs_trans *tp,
129 : const struct xfs_rtalloc_rec *rec,
130 : void *priv)
131 : {
132 16643782 : struct xfs_scrub *sc = priv;
133 16643782 : xfs_fileoff_t rbmoff;
134 16643782 : xfs_rtblock_t rtbno;
135 16643782 : xfs_filblks_t rtlen;
136 16643782 : xchk_rtsumoff_t offs;
137 16643782 : unsigned int lenlog;
138 16643782 : xfs_suminfo_t v = 0;
139 16643782 : int error = 0;
140 :
141 16643782 : if (xchk_should_terminate(sc, &error))
142 0 : return error;
143 :
144 : /* Compute the relevant location in the rtsum file. */
145 16643782 : rbmoff = XFS_BITTOBLOCK(mp, rec->ar_startext);
146 16643782 : lenlog = XFS_RTBLOCKLOG(rec->ar_extcount);
147 16643782 : offs = XFS_SUMOFFS(mp, lenlog, rbmoff);
148 :
149 16643782 : rtbno = rec->ar_startext * mp->m_sb.sb_rextsize;
150 16643782 : rtlen = rec->ar_extcount * mp->m_sb.sb_rextsize;
151 :
152 16643782 : if (!xfs_verify_rtext(mp, rtbno, rtlen)) {
153 0 : xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
154 0 : return -EFSCORRUPTED;
155 : }
156 :
157 : /* Bump the summary count. */
158 16643782 : error = xfsum_load(sc, offs, &v);
159 16643782 : if (error)
160 : return error;
161 :
162 16643782 : v++;
163 16643782 : trace_xchk_rtsum_record_free(mp, rec->ar_startext, rec->ar_extcount,
164 : lenlog, offs, v);
165 :
166 16643782 : return xfsum_store(sc, offs, v);
167 : }
168 :
169 : /* Compute the realtime summary from the realtime bitmap. */
170 : STATIC int
171 38028 : xchk_rtsum_compute(
172 : struct xfs_scrub *sc)
173 : {
174 38028 : struct xfs_mount *mp = sc->mp;
175 38028 : unsigned long long rtbmp_bytes;
176 :
177 : /* If the bitmap size doesn't match the computed size, bail. */
178 38028 : rtbmp_bytes = howmany_64(mp->m_sb.sb_rextents, NBBY);
179 38028 : if (roundup_64(rtbmp_bytes, mp->m_sb.sb_blocksize) !=
180 38028 : mp->m_rbmip->i_disk_size)
181 : return -EFSCORRUPTED;
182 :
183 38028 : return xfs_rtalloc_query_all(sc->mp, sc->tp, xchk_rtsum_record_free,
184 : sc);
185 : }
186 :
187 : /* Compare the rtsummary file against the one we computed. */
188 : STATIC int
189 38028 : xchk_rtsum_compare(
190 : struct xfs_scrub *sc)
191 : {
192 38028 : struct xfs_mount *mp = sc->mp;
193 38028 : struct xfs_buf *bp;
194 38028 : struct xfs_bmbt_irec map;
195 38028 : xfs_fileoff_t off;
196 38028 : xchk_rtsumoff_t sumoff = 0;
197 38028 : int nmap;
198 :
199 280035 : for (off = 0; off < XFS_B_TO_FSB(mp, mp->m_rsumsize); off++) {
200 242007 : int error = 0;
201 :
202 242007 : if (xchk_should_terminate(sc, &error))
203 0 : return error;
204 242007 : if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
205 : return 0;
206 :
207 : /* Make sure we have a written extent. */
208 242007 : nmap = 1;
209 242007 : error = xfs_bmapi_read(mp->m_rsumip, off, 1, &map, &nmap,
210 : XFS_DATA_FORK);
211 242007 : if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
212 0 : return error;
213 :
214 242007 : if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
215 0 : xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
216 0 : return 0;
217 : }
218 :
219 : /* Read a block's worth of ondisk rtsummary file. */
220 242007 : error = xfs_rtbuf_get(mp, sc->tp, off, 1, &bp);
221 242007 : if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
222 0 : return error;
223 :
224 : /* Read a block's worth of computed rtsummary file. */
225 242007 : error = xfsum_copyout(sc, sumoff, sc->buf, mp->m_blockwsize);
226 242007 : if (error) {
227 0 : xfs_trans_brelse(sc->tp, bp);
228 0 : return error;
229 : }
230 :
231 242007 : if (memcmp(bp->b_addr, sc->buf,
232 242007 : mp->m_blockwsize << XFS_WORDLOG) != 0)
233 0 : xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
234 :
235 242007 : xfs_trans_brelse(sc->tp, bp);
236 242007 : sumoff += mp->m_blockwsize;
237 : }
238 :
239 : return 0;
240 : }
241 :
242 : /* Scrub the realtime summary. */
243 : int
244 38028 : xchk_rtsummary(
245 : struct xfs_scrub *sc)
246 : {
247 38028 : struct xfs_mount *mp = sc->mp;
248 38028 : int error = 0;
249 :
250 : /* Invoke the fork scrubber. */
251 38028 : error = xchk_metadata_inode_forks(sc);
252 38028 : if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
253 0 : goto out_rbm;
254 :
255 : /* Construct the new summary file from the rtbitmap. */
256 38028 : error = xchk_rtsum_compute(sc);
257 38028 : if (error == -EFSCORRUPTED) {
258 : /*
259 : * EFSCORRUPTED means the rtbitmap is corrupt, which is an xref
260 : * error since we're checking the summary file.
261 : */
262 0 : xchk_ino_xref_set_corrupt(sc, mp->m_rbmip->i_ino);
263 0 : error = 0;
264 0 : goto out_rbm;
265 : }
266 38028 : if (error)
267 0 : goto out_rbm;
268 :
269 : /* Does the computed summary file match the actual rtsummary file? */
270 38028 : error = xchk_rtsum_compare(sc);
271 :
272 38028 : out_rbm:
273 : /* Unlock the rtbitmap since we're done with it. */
274 38028 : xfs_iunlock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);
275 38028 : return error;
276 : }
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