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 #ifndef __XFS_SCRUB_SCRUB_H__
7 #define __XFS_SCRUB_SCRUB_H__
8
9 struct xfs_scrub;
10
11 struct xchk_relax {
12 unsigned long next_resched;
13 unsigned int resched_nr;
14 bool interruptible;
15 };
16
17 /* Yield to the scheduler at most 10x per second. */
18 #define XCHK_RELAX_NEXT (jiffies + (HZ / 10))
19
20 #define INIT_XCHK_RELAX \
21 (struct xchk_relax){ \
22 .next_resched = XCHK_RELAX_NEXT, \
23 .resched_nr = 0, \
24 .interruptible = true, \
25 }
26
27 /*
28 * Relax during a scrub operation and exit if there's a fatal signal pending.
29 *
30 * If preemption is disabled, we need to yield to the scheduler every now and
31 * then so that we don't run afoul of the soft lockup watchdog or RCU stall
32 * detector. cond_resched calls are somewhat expensive (~5ns) so we want to
33 * ratelimit this to 10x per second. Amortize the cost of the other checks by
34 * only doing it once every 100 calls.
35 */
36 static inline int xchk_maybe_relax(struct xchk_relax *widget)
37 {
38 /* Amortize the cost of scheduling and checking signals. */
39 if (likely(++widget->resched_nr < 100))
40 return 0;
41 widget->resched_nr = 0;
42
43 if (unlikely(widget->next_resched <= jiffies)) {
44 cond_resched();
45 widget->next_resched = XCHK_RELAX_NEXT;
46 }
47
48 if (widget->interruptible && fatal_signal_pending(current))
49 return -EINTR;
50
51 return 0;
52 }
53
54 /*
55 * Standard flags for allocating memory within scrub. NOFS context is
56 * configured by the process allocation scope. Scrub and repair must be able
57 * to back out gracefully if there isn't enough memory. Force-cast to avoid
58 * complaints from static checkers.
59 */
60 #define XCHK_GFP_FLAGS ((__force gfp_t)(GFP_KERNEL | __GFP_NOWARN | \
61 __GFP_RETRY_MAYFAIL))
62
63 /*
64 * For opening files by handle for fsck operations, we don't trust the inumber
65 * or the allocation state; therefore, perform an untrusted lookup. We don't
66 * want these inodes to pollute the cache, so mark them for immediate removal.
67 */
68 #define XCHK_IGET_FLAGS (XFS_IGET_UNTRUSTED | XFS_IGET_DONTCACHE)
69
70 /* Type info and names for the scrub types. */
71 enum xchk_type {
72 ST_NONE = 1, /* disabled */
73 ST_PERAG, /* per-AG metadata */
74 ST_FS, /* per-FS metadata */
75 ST_INODE, /* per-inode metadata */
76 };
77
78 struct xchk_meta_ops {
79 /* Acquire whatever resources are needed for the operation. */
80 int (*setup)(struct xfs_scrub *sc);
81
82 /* Examine metadata for errors. */
83 int (*scrub)(struct xfs_scrub *);
84
85 /* Repair or optimize the metadata. */
86 int (*repair)(struct xfs_scrub *);
87
88 /*
89 * Re-scrub the metadata we repaired, in case there's extra work that
90 * we need to do to check our repair work. If this is NULL, we'll use
91 * the ->scrub function pointer, assuming that the regular scrub is
92 * sufficient.
93 */
94 int (*repair_eval)(struct xfs_scrub *sc);
95
96 /* Decide if we even have this piece of metadata. */
97 bool (*has)(struct xfs_mount *);
98
99 /* type describing required/allowed inputs */
100 enum xchk_type type;
101 };
102
103 /* Buffer pointers and btree cursors for an entire AG. */
104 struct xchk_ag {
105 struct xfs_perag *pag;
106
107 /* AG btree roots */
108 struct xfs_buf *agf_bp;
109 struct xfs_buf *agi_bp;
110
111 /* AG btrees */
112 struct xfs_btree_cur *bno_cur;
113 struct xfs_btree_cur *cnt_cur;
114 struct xfs_btree_cur *ino_cur;
115 struct xfs_btree_cur *fino_cur;
116 struct xfs_btree_cur *rmap_cur;
117 struct xfs_btree_cur *refc_cur;
118 };
119
120 struct xfs_scrub {
121 /* General scrub state. */
122 struct xfs_mount *mp;
123 struct xfs_scrub_metadata *sm;
124 const struct xchk_meta_ops *ops;
125 struct xfs_trans *tp;
126
127 /* File that scrub was called with. */
128 struct file *file;
129
130 /*
131 * File that is undergoing the scrub operation. This can differ from
132 * the file that scrub was called with if we're checking file-based fs
133 * metadata (e.g. rt bitmaps) or if we're doing a scrub-by-handle for
134 * something that can't be opened directly (e.g. symlinks).
135 */
136 struct xfs_inode *ip;
137
138 /* Kernel memory buffer used by scrubbers; freed at teardown. */
139 void *buf;
140
141 /*
142 * Clean up resources owned by whatever is in the buffer. Cleanup can
143 * be deferred with this hook as a means for scrub functions to pass
144 * data to repair functions. This function must not free the buffer
145 * itself.
146 */
147 void (*buf_cleanup)(void *buf);
148
149 /* xfile used by the scrubbers; freed at teardown. */
150 struct xfile *xfile;
151
152 /* buffer target for in-memory btrees; also freed at teardown. */
153 struct xfs_buftarg *xmbtp;
154
155 /* Lock flags for @ip. */
156 uint ilock_flags;
157
158 /* The orphanage, for stashing files that have lost their parent. */
159 uint orphanage_ilock_flags;
160 struct xfs_inode *orphanage;
161
162 /* A temporary file on this filesystem, for staging new metadata. */
163 struct xfs_inode *tempip;
164 uint temp_ilock_flags;
165
166 /* See the XCHK/XREP state flags below. */
167 unsigned int flags;
168
169 /*
170 * The XFS_SICK_* flags that correspond to the metadata being scrubbed
171 * or repaired. We will use this mask to update the in-core fs health
172 * status with whatever we find.
173 */
174 unsigned int sick_mask;
175
176 /* next time we want to cond_resched() */
177 struct xchk_relax relax;
178
179 /* State tracking for single-AG operations. */
180 struct xchk_ag sa;
181 };
182
183 /* XCHK state flags grow up from zero, XREP state flags grown down from 2^31 */
184 #define XCHK_TRY_HARDER (1U << 0) /* can't get resources, try again */
185 #define XCHK_HAVE_FREEZE_PROT (1U << 1) /* do we have freeze protection? */
186 #define XCHK_FSGATES_DRAIN (1U << 2) /* defer ops draining enabled */
187 #define XCHK_NEED_DRAIN (1U << 3) /* scrub needs to drain defer ops */
188 #define XCHK_FSGATES_QUOTA (1U << 4) /* quota live update enabled */
189 #define XCHK_FSGATES_DIRENTS (1U << 5) /* directory live update enabled */
190 #define XCHK_FSGATES_RMAP (1U << 6) /* rmapbt live update enabled */
191 #define XREP_RESET_PERAG_RESV (1U << 30) /* must reset AG space reservation */
192 #define XREP_ALREADY_FIXED (1U << 31) /* checking our repair work */
193
194 /*
195 * The XCHK_FSGATES* flags reflect functionality in the main filesystem that
196 * are only enabled for this particular online fsck. When not in use, the
197 * features are gated off via dynamic code patching, which is why the state
198 * must be enabled during scrub setup and can only be torn down afterwards.
199 */
200 #define XCHK_FSGATES_ALL (XCHK_FSGATES_DRAIN | \
201 XCHK_FSGATES_QUOTA | \
202 XCHK_FSGATES_DIRENTS | \
203 XCHK_FSGATES_RMAP)
204
205 struct xfs_scrub_subord {
206 struct xfs_scrub sc;
207 struct xfs_scrub *parent_sc;
208 unsigned int old_smtype;
209 unsigned int old_smflags;
210 };
211
212 struct xfs_scrub_subord *xchk_scrub_create_subord(struct xfs_scrub *sc,
213 unsigned int subtype);
214 void xchk_scrub_free_subord(struct xfs_scrub_subord *sub);
215
216 /*
217 * We /could/ terminate a scrub/repair operation early. If we're not
218 * in a good place to continue (fatal signal, etc.) then bail out.
219 * Note that we're careful not to make any judgements about *error.
220 */
221 static inline bool
222 xchk_should_terminate(
223 struct xfs_scrub *sc,
224 int *error)
225 {
226 if (xchk_maybe_relax(&sc->relax)) {
227 if (*error == 0)
228 *error = -EINTR;
229 return true;
230 }
231 return false;
232 }
233
234 /* Metadata scrubbers */
235 int xchk_tester(struct xfs_scrub *sc);
236 int xchk_superblock(struct xfs_scrub *sc);
237 int xchk_agf(struct xfs_scrub *sc);
238 int xchk_agfl(struct xfs_scrub *sc);
239 int xchk_agi(struct xfs_scrub *sc);
240 int xchk_allocbt(struct xfs_scrub *sc);
241 int xchk_iallocbt(struct xfs_scrub *sc);
242 int xchk_rmapbt(struct xfs_scrub *sc);
243 int xchk_refcountbt(struct xfs_scrub *sc);
244 int xchk_inode(struct xfs_scrub *sc);
245 int xchk_bmap_data(struct xfs_scrub *sc);
246 int xchk_bmap_attr(struct xfs_scrub *sc);
247 int xchk_bmap_cow(struct xfs_scrub *sc);
248 int xchk_directory(struct xfs_scrub *sc);
249 int xchk_xattr(struct xfs_scrub *sc);
250 int xchk_symlink(struct xfs_scrub *sc);
251 int xchk_parent(struct xfs_scrub *sc);
252 int xchk_dirtree(struct xfs_scrub *sc);
253 #ifdef CONFIG_XFS_RT
254 int xchk_rtbitmap(struct xfs_scrub *sc);
255 int xchk_rtsummary(struct xfs_scrub *sc);
256 #else
257 static inline int
258 xchk_rtbitmap(struct xfs_scrub *sc)
259 {
260 return -ENOENT;
261 }
262 static inline int
263 xchk_rtsummary(struct xfs_scrub *sc)
264 {
265 return -ENOENT;
266 }
267 #endif
268 #ifdef CONFIG_XFS_QUOTA
269 int xchk_quota(struct xfs_scrub *sc);
270 int xchk_quotacheck(struct xfs_scrub *sc);
271 #else
272 static inline int
273 xchk_quota(struct xfs_scrub *sc)
274 {
275 return -ENOENT;
276 }
277 static inline int
278 xchk_quotacheck(struct xfs_scrub *sc)
279 {
280 return -ENOENT;
281 }
282 #endif
283 int xchk_fscounters(struct xfs_scrub *sc);
284 int xchk_nlinks(struct xfs_scrub *sc);
285
286 /* cross-referencing helpers */
287 void xchk_xref_is_used_space(struct xfs_scrub *sc, xfs_agblock_t agbno,
288 xfs_extlen_t len);
289 void xchk_xref_is_not_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
290 xfs_extlen_t len);
291 void xchk_xref_is_inode_chunk(struct xfs_scrub *sc, xfs_agblock_t agbno,
292 xfs_extlen_t len);
293 void xchk_xref_is_only_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
294 xfs_extlen_t len, const struct xfs_owner_info *oinfo);
295 void xchk_xref_is_not_owned_by(struct xfs_scrub *sc, xfs_agblock_t agbno,
296 xfs_extlen_t len, const struct xfs_owner_info *oinfo);
297 void xchk_xref_has_no_owner(struct xfs_scrub *sc, xfs_agblock_t agbno,
298 xfs_extlen_t len);
299 void xchk_xref_is_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
300 xfs_extlen_t len);
301 void xchk_xref_is_not_shared(struct xfs_scrub *sc, xfs_agblock_t bno,
302 xfs_extlen_t len);
303 void xchk_xref_is_not_cow_staging(struct xfs_scrub *sc, xfs_agblock_t bno,
304 xfs_extlen_t len);
305 #ifdef CONFIG_XFS_RT
306 void xchk_xref_is_used_rt_space(struct xfs_scrub *sc, xfs_rtblock_t rtbno,
307 xfs_extlen_t len);
308 #else
309 # define xchk_xref_is_used_rt_space(sc, rtbno, len) do { } while (0)
310 #endif
311
312 #endif /* __XFS_SCRUB_SCRUB_H__ */
313
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