1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "fs.h"
4 #include "messages.h"
5 #include "discard.h"
6 #include "super.h"
7
8 #ifdef CONFIG_PRINTK
9
10 #define STATE_STRING_PREFACE " state "
11 #define STATE_STRING_BUF_LEN (sizeof(STATE_STRING_PREFACE) + BTRFS_FS_STATE_COUNT + 1)
12
13 /*
14 * Characters to print to indicate error conditions or uncommon filesystem state.
15 * RO is not an error.
16 */
17 static const char fs_state_chars[] = {
18 [BTRFS_FS_STATE_REMOUNTING] = 'M',
19 [BTRFS_FS_STATE_RO] = 0,
20 [BTRFS_FS_STATE_TRANS_ABORTED] = 'A',
21 [BTRFS_FS_STATE_DEV_REPLACING] = 'R',
22 [BTRFS_FS_STATE_DUMMY_FS_INFO] = 0,
23 [BTRFS_FS_STATE_NO_DATA_CSUMS] = 'C',
24 [BTRFS_FS_STATE_SKIP_META_CSUMS] = 'S',
25 [BTRFS_FS_STATE_LOG_CLEANUP_ERROR] = 'L',
26 };
27
btrfs_state_to_string(const struct btrfs_fs_info * info,char * buf)28 static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *buf)
29 {
30 unsigned int bit;
31 bool states_printed = false;
32 unsigned long fs_state = READ_ONCE(info->fs_state);
33 char *curr = buf;
34
35 memcpy(curr, STATE_STRING_PREFACE, sizeof(STATE_STRING_PREFACE));
36 curr += sizeof(STATE_STRING_PREFACE) - 1;
37
38 if (BTRFS_FS_ERROR(info)) {
39 *curr++ = 'E';
40 states_printed = true;
41 }
42
43 for_each_set_bit(bit, &fs_state, sizeof(fs_state)) {
44 WARN_ON_ONCE(bit >= BTRFS_FS_STATE_COUNT);
45 if ((bit < BTRFS_FS_STATE_COUNT) && fs_state_chars[bit]) {
46 *curr++ = fs_state_chars[bit];
47 states_printed = true;
48 }
49 }
50
51 /* If no states were printed, reset the buffer */
52 if (!states_printed)
53 curr = buf;
54
55 *curr++ = 0;
56 }
57 #endif
58
59 /*
60 * Generally the error codes correspond to their respective errors, but there
61 * are a few special cases.
62 *
63 * EUCLEAN: Any sort of corruption that we encounter. The tree-checker for
64 * instance will return EUCLEAN if any of the blocks are corrupted in
65 * a way that is problematic. We want to reserve EUCLEAN for these
66 * sort of corruptions.
67 *
68 * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we
69 * need to use EROFS for this case. We will have no idea of the
70 * original failure, that will have been reported at the time we tripped
71 * over the error. Each subsequent error that doesn't have any context
72 * of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR.
73 */
btrfs_decode_error(int error)74 const char * __attribute_const__ btrfs_decode_error(int error)
75 {
76 char *errstr = "unknown";
77
78 switch (error) {
79 case -ENOENT: /* -2 */
80 errstr = "No such entry";
81 break;
82 case -EIO: /* -5 */
83 errstr = "IO failure";
84 break;
85 case -ENOMEM: /* -12*/
86 errstr = "Out of memory";
87 break;
88 case -EEXIST: /* -17 */
89 errstr = "Object already exists";
90 break;
91 case -ENOSPC: /* -28 */
92 errstr = "No space left";
93 break;
94 case -EROFS: /* -30 */
95 errstr = "Readonly filesystem";
96 break;
97 case -EOPNOTSUPP: /* -95 */
98 errstr = "Operation not supported";
99 break;
100 case -EUCLEAN: /* -117 */
101 errstr = "Filesystem corrupted";
102 break;
103 case -EDQUOT: /* -122 */
104 errstr = "Quota exceeded";
105 break;
106 }
107
108 return errstr;
109 }
110
111 /*
112 * Decodes expected errors from the caller and invokes the appropriate error
113 * response.
114 */
115 __cold
__btrfs_handle_fs_error(struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int error,const char * fmt,...)116 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
117 unsigned int line, int error, const char *fmt, ...)
118 {
119 struct super_block *sb = fs_info->sb;
120 #ifdef CONFIG_PRINTK
121 char statestr[STATE_STRING_BUF_LEN];
122 const char *errstr;
123 #endif
124
125 #ifdef CONFIG_PRINTK_INDEX
126 printk_index_subsys_emit(
127 "BTRFS: error (device %s%s) in %s:%d: errno=%d %s", KERN_CRIT, fmt);
128 #endif
129
130 /*
131 * Special case: if the error is EROFS, and we're already under
132 * SB_RDONLY, then it is safe here.
133 */
134 if (error == -EROFS && sb_rdonly(sb))
135 return;
136
137 #ifdef CONFIG_PRINTK
138 errstr = btrfs_decode_error(error);
139 btrfs_state_to_string(fs_info, statestr);
140 if (fmt) {
141 struct va_format vaf;
142 va_list args;
143
144 va_start(args, fmt);
145 vaf.fmt = fmt;
146 vaf.va = &args;
147
148 pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s (%pV)\n",
149 sb->s_id, statestr, function, line, error, errstr, &vaf);
150 va_end(args);
151 } else {
152 pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s\n",
153 sb->s_id, statestr, function, line, error, errstr);
154 }
155 #endif
156
157 /*
158 * Today we only save the error info to memory. Long term we'll also
159 * send it down to the disk.
160 */
161 WRITE_ONCE(fs_info->fs_error, error);
162
163 /* Don't go through full error handling during mount. */
164 if (!(sb->s_flags & SB_BORN))
165 return;
166
167 if (sb_rdonly(sb))
168 return;
169
170 btrfs_discard_stop(fs_info);
171
172 /* Handle error by forcing the filesystem readonly. */
173 btrfs_set_sb_rdonly(sb);
174 btrfs_info(fs_info, "forced readonly");
175 /*
176 * Note that a running device replace operation is not canceled here
177 * although there is no way to update the progress. It would add the
178 * risk of a deadlock, therefore the canceling is omitted. The only
179 * penalty is that some I/O remains active until the procedure
180 * completes. The next time when the filesystem is mounted writable
181 * again, the device replace operation continues.
182 */
183 }
184
185 #ifdef CONFIG_PRINTK
186 static const char * const logtypes[] = {
187 "emergency",
188 "alert",
189 "critical",
190 "error",
191 "warning",
192 "notice",
193 "info",
194 "debug",
195 };
196
197 /*
198 * Use one ratelimit state per log level so that a flood of less important
199 * messages doesn't cause more important ones to be dropped.
200 */
201 static struct ratelimit_state printk_limits[] = {
202 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
203 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
204 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
205 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
206 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
207 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
208 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
209 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
210 };
211
_btrfs_printk(const struct btrfs_fs_info * fs_info,const char * fmt,...)212 void __cold _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
213 {
214 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
215 struct va_format vaf;
216 va_list args;
217 int kern_level;
218 const char *type = logtypes[4];
219 struct ratelimit_state *ratelimit = &printk_limits[4];
220
221 #ifdef CONFIG_PRINTK_INDEX
222 printk_index_subsys_emit("%sBTRFS %s (device %s): ", NULL, fmt);
223 #endif
224
225 va_start(args, fmt);
226
227 while ((kern_level = printk_get_level(fmt)) != 0) {
228 size_t size = printk_skip_level(fmt) - fmt;
229
230 if (kern_level >= '0' && kern_level <= '7') {
231 memcpy(lvl, fmt, size);
232 lvl[size] = '\0';
233 type = logtypes[kern_level - '0'];
234 ratelimit = &printk_limits[kern_level - '0'];
235 }
236 fmt += size;
237 }
238
239 vaf.fmt = fmt;
240 vaf.va = &args;
241
242 if (__ratelimit(ratelimit)) {
243 if (fs_info) {
244 char statestr[STATE_STRING_BUF_LEN];
245
246 btrfs_state_to_string(fs_info, statestr);
247 _printk("%sBTRFS %s (device %s%s): %pV\n", lvl, type,
248 fs_info->sb->s_id, statestr, &vaf);
249 } else {
250 _printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
251 }
252 }
253
254 va_end(args);
255 }
256 #endif
257
258 #if BITS_PER_LONG == 32
btrfs_warn_32bit_limit(struct btrfs_fs_info * fs_info)259 void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
260 {
261 if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
262 btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
263 btrfs_warn(fs_info,
264 "due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
265 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
266 btrfs_warn(fs_info,
267 "please consider upgrading to 64bit kernel/hardware");
268 }
269 }
270
btrfs_err_32bit_limit(struct btrfs_fs_info * fs_info)271 void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
272 {
273 if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
274 btrfs_err(fs_info, "reached 32bit limit for logical addresses");
275 btrfs_err(fs_info,
276 "due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
277 BTRFS_32BIT_MAX_FILE_SIZE >> 40);
278 btrfs_err(fs_info,
279 "please consider upgrading to 64bit kernel/hardware");
280 }
281 }
282 #endif
283
284 /*
285 * Decode unexpected, fatal errors from the caller, issue an alert, and either
286 * panic or BUGs, depending on mount options.
287 */
288 __cold
__btrfs_panic(const struct btrfs_fs_info * fs_info,const char * function,unsigned int line,int error,const char * fmt,...)289 void __btrfs_panic(const struct btrfs_fs_info *fs_info, const char *function,
290 unsigned int line, int error, const char *fmt, ...)
291 {
292 char *s_id = "<unknown>";
293 const char *errstr;
294 struct va_format vaf = { .fmt = fmt };
295 va_list args;
296
297 if (fs_info)
298 s_id = fs_info->sb->s_id;
299
300 va_start(args, fmt);
301 vaf.va = &args;
302
303 errstr = btrfs_decode_error(error);
304 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
305 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
306 s_id, function, line, &vaf, error, errstr);
307
308 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
309 function, line, &vaf, error, errstr);
310 va_end(args);
311 /* Caller calls BUG() */
312 }
313