1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 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_bit.h"
10#include "xfs_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_log_format.h"
14#include "xfs_trans.h"
15#include "xfs_inode.h"
16#include "xfs_quota.h"
17#include "xfs_qm.h"
18#include "xfs_bmap.h"
19#include "scrub/scrub.h"
20#include "scrub/common.h"
21#include "scrub/quota.h"
22#include "scrub/trace.h"
23
24/* Initialize a dquot iteration cursor. */
25void
26xchk_dqiter_init(
27 struct xchk_dqiter *cursor,
28 struct xfs_scrub *sc,
29 xfs_dqtype_t dqtype)
30{
31 cursor->sc = sc;
32 cursor->bmap.br_startoff = NULLFILEOFF;
33 cursor->dqtype = dqtype & XFS_DQTYPE_REC_MASK;
34 cursor->quota_ip = xfs_quota_inode(sc->mp, cursor->dqtype);
35 cursor->id = 0;
36}
37
38/*
39 * Ensure that the cached data fork mapping for the dqiter cursor is fresh and
40 * covers the dquot pointed to by the scan cursor.
41 */
42STATIC int
43xchk_dquot_iter_revalidate_bmap(
44 struct xchk_dqiter *cursor)
45{
46 struct xfs_quotainfo *qi = cursor->sc->mp->m_quotainfo;
47 struct xfs_ifork *ifp = xfs_ifork_ptr(cursor->quota_ip,
48 XFS_DATA_FORK);
49 xfs_fileoff_t fileoff;
50 xfs_dqid_t this_id = cursor->id;
51 int nmaps = 1;
52 int error;
53
54 fileoff = this_id / qi->qi_dqperchunk;
55
56 /*
57 * If we have a mapping for cursor->id and it's still fresh, there's
58 * no need to reread the bmbt.
59 */
60 if (cursor->bmap.br_startoff != NULLFILEOFF &&
61 cursor->if_seq == ifp->if_seq &&
62 cursor->bmap.br_startoff + cursor->bmap.br_blockcount > fileoff)
63 return 0;
64
65 /* Look up the data fork mapping for the dquot id of interest. */
66 error = xfs_bmapi_read(cursor->quota_ip, fileoff,
67 XFS_MAX_FILEOFF - fileoff, &cursor->bmap, &nmaps, 0);
68 if (error)
69 return error;
70 if (!nmaps) {
71 ASSERT(nmaps > 0);
72 return -EFSCORRUPTED;
73 }
74 if (cursor->bmap.br_startoff > fileoff) {
75 ASSERT(cursor->bmap.br_startoff == fileoff);
76 return -EFSCORRUPTED;
77 }
78
79 cursor->if_seq = ifp->if_seq;
80 trace_xchk_dquot_iter_revalidate_bmap(cursor, cursor->id);
81 return 0;
82}
83
84/* Advance the dqiter cursor to the next non-sparse region of the quota file. */
85STATIC int
86xchk_dquot_iter_advance_bmap(
87 struct xchk_dqiter *cursor,
88 uint64_t *next_ondisk_id)
89{
90 struct xfs_quotainfo *qi = cursor->sc->mp->m_quotainfo;
91 struct xfs_ifork *ifp = xfs_ifork_ptr(cursor->quota_ip,
92 XFS_DATA_FORK);
93 xfs_fileoff_t fileoff;
94 uint64_t next_id;
95 int nmaps = 1;
96 int error;
97
98 /* Find the dquot id for the next non-hole mapping. */
99 do {
100 fileoff = cursor->bmap.br_startoff + cursor->bmap.br_blockcount;
101 if (fileoff > XFS_DQ_ID_MAX / qi->qi_dqperchunk) {
102 /* The hole goes beyond the max dquot id, we're done */
103 *next_ondisk_id = -1ULL;
104 return 0;
105 }
106
107 error = xfs_bmapi_read(cursor->quota_ip, fileoff,
108 XFS_MAX_FILEOFF - fileoff, &cursor->bmap,
109 &nmaps, 0);
110 if (error)
111 return error;
112 if (!nmaps) {
113 /* Must have reached the end of the mappings. */
114 *next_ondisk_id = -1ULL;
115 return 0;
116 }
117 if (cursor->bmap.br_startoff > fileoff) {
118 ASSERT(cursor->bmap.br_startoff == fileoff);
119 return -EFSCORRUPTED;
120 }
121 } while (!xfs_bmap_is_real_extent(&cursor->bmap));
122
123 next_id = cursor->bmap.br_startoff * qi->qi_dqperchunk;
124 if (next_id > XFS_DQ_ID_MAX) {
125 /* The hole goes beyond the max dquot id, we're done */
126 *next_ondisk_id = -1ULL;
127 return 0;
128 }
129
130 /* Propose jumping forward to the dquot in the next allocated block. */
131 *next_ondisk_id = next_id;
132 cursor->if_seq = ifp->if_seq;
133 trace_xchk_dquot_iter_advance_bmap(cursor, *next_ondisk_id);
134 return 0;
135}
136
137/*
138 * Find the id of the next highest incore dquot. Normally this will correspond
139 * exactly with the quota file block mappings, but repair might have erased a
140 * mapping because it was crosslinked; in that case, we need to re-allocate the
141 * space so that we can reset q_blkno.
142 */
143STATIC void
144xchk_dquot_iter_advance_incore(
145 struct xchk_dqiter *cursor,
146 uint64_t *next_incore_id)
147{
148 struct xfs_quotainfo *qi = cursor->sc->mp->m_quotainfo;
149 struct radix_tree_root *tree = xfs_dquot_tree(qi, cursor->dqtype);
150 struct xfs_dquot *dq;
151 unsigned int nr_found;
152
153 *next_incore_id = -1ULL;
154
155 mutex_lock(&qi->qi_tree_lock);
156 nr_found = radix_tree_gang_lookup(tree, (void **)&dq, cursor->id, 1);
157 if (nr_found)
158 *next_incore_id = dq->q_id;
159 mutex_unlock(&qi->qi_tree_lock);
160
161 trace_xchk_dquot_iter_advance_incore(cursor, *next_incore_id);
162}
163
164/*
165 * Walk all incore dquots of this filesystem. Caller must set *@cursorp to
166 * zero before the first call, and must not hold the quota file ILOCK.
167 * Returns 1 and a valid *@dqpp; 0 and *@dqpp == NULL when there are no more
168 * dquots to iterate; or a negative errno.
169 */
170int
171xchk_dquot_iter(
172 struct xchk_dqiter *cursor,
173 struct xfs_dquot **dqpp)
174{
175 struct xfs_mount *mp = cursor->sc->mp;
176 struct xfs_dquot *dq = NULL;
177 uint64_t next_ondisk, next_incore = -1ULL;
178 unsigned int lock_mode;
179 int error = 0;
180
181 if (cursor->id > XFS_DQ_ID_MAX)
182 return 0;
183 next_ondisk = cursor->id;
184
185 /* Revalidate and/or advance the cursor. */
186 lock_mode = xfs_ilock_data_map_shared(cursor->quota_ip);
187 error = xchk_dquot_iter_revalidate_bmap(cursor);
188 if (!error && !xfs_bmap_is_real_extent(&cursor->bmap))
189 error = xchk_dquot_iter_advance_bmap(cursor, &next_ondisk);
190 xfs_iunlock(cursor->quota_ip, lock_mode);
191 if (error)
192 return error;
193
194 if (next_ondisk > cursor->id)
195 xchk_dquot_iter_advance_incore(cursor, &next_incore);
196
197 /* Pick the next dquot in the sequence and return it. */
198 cursor->id = min(next_ondisk, next_incore);
199 if (cursor->id > XFS_DQ_ID_MAX)
200 return 0;
201
202 trace_xchk_dquot_iter(cursor, cursor->id);
203
204 error = xfs_qm_dqget(mp, cursor->id, cursor->dqtype, false, &dq);
205 if (error)
206 return error;
207
208 cursor->id = dq->q_id + 1;
209 *dqpp = dq;
210 return 1;
211}
212

source code of linux/fs/xfs/scrub/dqiterate.c