xref: /linux/fs/xfs/scrub/rtbitmap.c (revision c148bc7535650fbfa95a1f571b9ffa2ab478ea33)
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_log_format.h"
14 #include "xfs_trans.h"
15 #include "xfs_rtbitmap.h"
16 #include "xfs_inode.h"
17 #include "xfs_bmap.h"
18 #include "xfs_bit.h"
19 #include "xfs_rtgroup.h"
20 #include "xfs_sb.h"
21 #include "xfs_rmap.h"
22 #include "xfs_rtrmap_btree.h"
23 #include "xfs_exchmaps.h"
24 #include "xfs_zone_alloc.h"
25 #include "scrub/scrub.h"
26 #include "scrub/common.h"
27 #include "scrub/repair.h"
28 #include "scrub/tempexch.h"
29 #include "scrub/rtbitmap.h"
30 #include "scrub/btree.h"
31 
32 /* Set us up with the realtime metadata locked. */
33 int
xchk_setup_rtbitmap(struct xfs_scrub * sc)34 xchk_setup_rtbitmap(
35 	struct xfs_scrub	*sc)
36 {
37 	struct xfs_mount	*mp = sc->mp;
38 	struct xchk_rtbitmap	*rtb;
39 	int			error;
40 
41 	if (xchk_need_intent_drain(sc))
42 		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
43 
44 	rtb = kzalloc(struct_size(rtb, words, xchk_rtbitmap_wordcnt(sc)),
45 			XCHK_GFP_FLAGS);
46 	if (!rtb)
47 		return -ENOMEM;
48 	sc->buf = rtb;
49 	rtb->sc = sc;
50 
51 	error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr);
52 	if (error)
53 		return error;
54 
55 	if (xchk_could_repair(sc)) {
56 		error = xrep_setup_rtbitmap(sc, rtb);
57 		if (error)
58 			return error;
59 	}
60 
61 	error = xchk_trans_alloc(sc, rtb->resblks);
62 	if (error)
63 		return error;
64 
65 	error = xchk_install_live_inode(sc, rtg_bitmap(sc->sr.rtg));
66 	if (error)
67 		return error;
68 
69 	error = xchk_ino_dqattach(sc);
70 	if (error)
71 		return error;
72 
73 	error = xchk_rtgroup_lock(sc, &sc->sr, XCHK_RTGLOCK_ALL);
74 	if (error)
75 		return error;
76 
77 	/*
78 	 * Now that we've locked the rtbitmap, we can't race with growfsrt
79 	 * trying to expand the bitmap or change the size of the rt volume.
80 	 * Hence it is safe to compute and check the geometry values.
81 	 */
82 	if (mp->m_sb.sb_rblocks) {
83 		rtb->rextents = xfs_blen_to_rtbxlen(mp, mp->m_sb.sb_rblocks);
84 		rtb->rextslog = xfs_compute_rextslog(rtb->rextents);
85 		rtb->rbmblocks = xfs_rtbitmap_blockcount(mp);
86 	}
87 
88 	return 0;
89 }
90 
91 /* Per-rtgroup bitmap contents. */
92 
93 /* Cross-reference rtbitmap entries with other metadata. */
94 STATIC void
xchk_rtbitmap_xref(struct xchk_rtbitmap * rtb,xfs_rtblock_t startblock,xfs_rtblock_t blockcount)95 xchk_rtbitmap_xref(
96 	struct xchk_rtbitmap	*rtb,
97 	xfs_rtblock_t		startblock,
98 	xfs_rtblock_t		blockcount)
99 {
100 	struct xfs_scrub	*sc = rtb->sc;
101 	xfs_rgblock_t		rgbno = xfs_rtb_to_rgbno(sc->mp, startblock);
102 
103 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
104 		return;
105 	if (!sc->sr.rmap_cur)
106 		return;
107 
108 	xchk_xref_has_no_rt_owner(sc, rgbno, blockcount);
109 	xchk_xref_is_not_rt_shared(sc, rgbno, blockcount);
110 	xchk_xref_is_not_rt_cow_staging(sc, rgbno, blockcount);
111 
112 	if (rtb->next_free_rgbno < rgbno)
113 		xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno,
114 				rgbno - rtb->next_free_rgbno);
115 	rtb->next_free_rgbno = rgbno + blockcount;
116 }
117 
118 /* Scrub a free extent record from the realtime bitmap. */
119 STATIC int
xchk_rtbitmap_rec(struct xfs_rtgroup * rtg,struct xfs_trans * tp,const struct xfs_rtalloc_rec * rec,void * priv)120 xchk_rtbitmap_rec(
121 	struct xfs_rtgroup	*rtg,
122 	struct xfs_trans	*tp,
123 	const struct xfs_rtalloc_rec *rec,
124 	void			*priv)
125 {
126 	struct xchk_rtbitmap	*rtb = priv;
127 	struct xfs_scrub	*sc = rtb->sc;
128 	xfs_rtblock_t		startblock;
129 	xfs_filblks_t		blockcount;
130 
131 	startblock = xfs_rtx_to_rtb(rtg, rec->ar_startext);
132 	blockcount = xfs_rtxlen_to_extlen(rtg_mount(rtg), rec->ar_extcount);
133 
134 	if (!xfs_verify_rtbext(rtg_mount(rtg), startblock, blockcount))
135 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
136 
137 	xchk_rtbitmap_xref(rtb, startblock, blockcount);
138 
139 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
140 		return -ECANCELED;
141 
142 	return 0;
143 }
144 
145 /* Make sure the entire rtbitmap file is mapped with written extents. */
146 STATIC int
xchk_rtbitmap_check_extents(struct xfs_scrub * sc)147 xchk_rtbitmap_check_extents(
148 	struct xfs_scrub	*sc)
149 {
150 	struct xfs_bmbt_irec	map;
151 	struct xfs_iext_cursor	icur;
152 	struct xfs_mount	*mp = sc->mp;
153 	struct xfs_inode	*ip = sc->ip;
154 	xfs_fileoff_t		off = 0;
155 	xfs_fileoff_t		endoff;
156 	int			error = 0;
157 
158 	/* Mappings may not cross or lie beyond EOF. */
159 	endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);
160 	if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {
161 		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);
162 		return 0;
163 	}
164 
165 	while (off < endoff) {
166 		int		nmap = 1;
167 
168 		if (xchk_should_terminate(sc, &error) ||
169 		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
170 			break;
171 
172 		/* Make sure we have a written extent. */
173 		error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,
174 				XFS_DATA_FORK);
175 		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))
176 			break;
177 
178 		if (nmap != 1 || !xfs_bmap_is_written_extent(&map)) {
179 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
180 			break;
181 		}
182 
183 		off += map.br_blockcount;
184 	}
185 
186 	return error;
187 }
188 
189 /* Scrub this group's realtime bitmap. */
190 int
xchk_rtbitmap(struct xfs_scrub * sc)191 xchk_rtbitmap(
192 	struct xfs_scrub	*sc)
193 {
194 	struct xfs_mount	*mp = sc->mp;
195 	struct xfs_rtgroup	*rtg = sc->sr.rtg;
196 	struct xfs_inode	*rbmip = rtg_bitmap(rtg);
197 	struct xchk_rtbitmap	*rtb = sc->buf;
198 	xfs_rgblock_t		last_rgbno;
199 	int			error;
200 
201 	/* Is sb_rextents correct? */
202 	if (mp->m_sb.sb_rextents != rtb->rextents) {
203 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
204 		return 0;
205 	}
206 
207 	/* Is sb_rextslog correct? */
208 	if (mp->m_sb.sb_rextslog != rtb->rextslog) {
209 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
210 		return 0;
211 	}
212 
213 	/*
214 	 * Is sb_rbmblocks large enough to handle the current rt volume?  In no
215 	 * case can we exceed 4bn bitmap blocks since the super field is a u32.
216 	 */
217 	if (rtb->rbmblocks > U32_MAX) {
218 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
219 		return 0;
220 	}
221 	if (mp->m_sb.sb_rbmblocks != rtb->rbmblocks) {
222 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
223 		return 0;
224 	}
225 
226 	/* The bitmap file length must be aligned to an fsblock. */
227 	if (rbmip->i_disk_size & mp->m_blockmask) {
228 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
229 		return 0;
230 	}
231 
232 	/*
233 	 * Is the bitmap file itself large enough to handle the rt volume?
234 	 * growfsrt expands the bitmap file before updating sb_rextents, so the
235 	 * file can be larger than sb_rbmblocks.
236 	 */
237 	if (rbmip->i_disk_size < XFS_FSB_TO_B(mp, rtb->rbmblocks)) {
238 		xchk_ino_set_corrupt(sc, rbmip->i_ino);
239 		return 0;
240 	}
241 
242 	/* Invoke the fork scrubber. */
243 	error = xchk_metadata_inode_forks(sc);
244 	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
245 		return error;
246 
247 	error = xchk_rtbitmap_check_extents(sc);
248 	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
249 		return error;
250 
251 	rtb->next_free_rgbno = 0;
252 	error = xfs_rtalloc_query_all(rtg, sc->tp, xchk_rtbitmap_rec, rtb);
253 	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
254 		return error;
255 
256 	/*
257 	 * Check that the are rmappings for all rt extents between the end of
258 	 * the last free extent we saw and the last possible extent in the rt
259 	 * group.
260 	 */
261 	last_rgbno = rtg->rtg_extents * mp->m_sb.sb_rextsize - 1;
262 	if (rtb->next_free_rgbno < last_rgbno)
263 		xchk_xref_has_rt_owner(sc, rtb->next_free_rgbno,
264 				last_rgbno - rtb->next_free_rgbno);
265 	return 0;
266 }
267 
268 /* xref check that the extent is not free in the rtbitmap */
269 void
xchk_xref_is_used_rt_space(struct xfs_scrub * sc,xfs_rtblock_t rtbno,xfs_extlen_t len)270 xchk_xref_is_used_rt_space(
271 	struct xfs_scrub	*sc,
272 	xfs_rtblock_t		rtbno,
273 	xfs_extlen_t		len)
274 {
275 	struct xfs_rtgroup	*rtg = sc->sr.rtg;
276 	xfs_rtxnum_t		startext;
277 	xfs_rtxnum_t		endext;
278 	bool			is_free;
279 	int			error;
280 
281 	if (xchk_skip_xref(sc->sm))
282 		return;
283 
284 	if (xfs_has_zoned(sc->mp)) {
285 		if (!xfs_zone_rgbno_is_valid(rtg,
286 				xfs_rtb_to_rgbno(sc->mp, rtbno) + len - 1))
287 			xchk_ino_xref_set_corrupt(sc, rtg_rmap(rtg)->i_ino);
288 		return;
289 	}
290 
291 	startext = xfs_rtb_to_rtx(sc->mp, rtbno);
292 	endext = xfs_rtb_to_rtx(sc->mp, rtbno + len - 1);
293 	error = xfs_rtalloc_extent_is_free(rtg, sc->tp, startext,
294 			endext - startext + 1, &is_free);
295 	if (!xchk_should_check_xref(sc, &error, NULL))
296 		return;
297 	if (is_free)
298 		xchk_ino_xref_set_corrupt(sc, rtg_bitmap(rtg)->i_ino);
299 }
300