xref: /linux/fs/btrfs/messages.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
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_CSUMS]		= 'C',
24 	[BTRFS_FS_STATE_LOG_CLEANUP_ERROR]	= 'L',
25 };
26 
27 static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *buf)
28 {
29 	unsigned int bit;
30 	bool states_printed = false;
31 	unsigned long fs_state = READ_ONCE(info->fs_state);
32 	char *curr = buf;
33 
34 	memcpy(curr, STATE_STRING_PREFACE, sizeof(STATE_STRING_PREFACE));
35 	curr += sizeof(STATE_STRING_PREFACE) - 1;
36 
37 	if (BTRFS_FS_ERROR(info)) {
38 		*curr++ = 'E';
39 		states_printed = true;
40 	}
41 
42 	for_each_set_bit(bit, &fs_state, sizeof(fs_state)) {
43 		WARN_ON_ONCE(bit >= BTRFS_FS_STATE_COUNT);
44 		if ((bit < BTRFS_FS_STATE_COUNT) && fs_state_chars[bit]) {
45 			*curr++ = fs_state_chars[bit];
46 			states_printed = true;
47 		}
48 	}
49 
50 	/* If no states were printed, reset the buffer */
51 	if (!states_printed)
52 		curr = buf;
53 
54 	*curr++ = 0;
55 }
56 #endif
57 
58 /*
59  * Generally the error codes correspond to their respective errors, but there
60  * are a few special cases.
61  *
62  * EUCLEAN: Any sort of corruption that we encounter.  The tree-checker for
63  *          instance will return EUCLEAN if any of the blocks are corrupted in
64  *          a way that is problematic.  We want to reserve EUCLEAN for these
65  *          sort of corruptions.
66  *
67  * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we
68  *        need to use EROFS for this case.  We will have no idea of the
69  *        original failure, that will have been reported at the time we tripped
70  *        over the error.  Each subsequent error that doesn't have any context
71  *        of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR.
72  */
73 const char * __attribute_const__ btrfs_decode_error(int error)
74 {
75 	char *errstr = "unknown";
76 
77 	switch (error) {
78 	case -ENOENT:		/* -2 */
79 		errstr = "No such entry";
80 		break;
81 	case -EIO:		/* -5 */
82 		errstr = "IO failure";
83 		break;
84 	case -ENOMEM:		/* -12*/
85 		errstr = "Out of memory";
86 		break;
87 	case -EEXIST:		/* -17 */
88 		errstr = "Object already exists";
89 		break;
90 	case -ENOSPC:		/* -28 */
91 		errstr = "No space left";
92 		break;
93 	case -EROFS:		/* -30 */
94 		errstr = "Readonly filesystem";
95 		break;
96 	case -EOPNOTSUPP:	/* -95 */
97 		errstr = "Operation not supported";
98 		break;
99 	case -EUCLEAN:		/* -117 */
100 		errstr = "Filesystem corrupted";
101 		break;
102 	case -EDQUOT:		/* -122 */
103 		errstr = "Quota exceeded";
104 		break;
105 	}
106 
107 	return errstr;
108 }
109 
110 /*
111  * Decodes expected errors from the caller and invokes the appropriate error
112  * response.
113  */
114 __cold
115 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
116 		       unsigned int line, int error, const char *fmt, ...)
117 {
118 	struct super_block *sb = fs_info->sb;
119 #ifdef CONFIG_PRINTK
120 	char statestr[STATE_STRING_BUF_LEN];
121 	const char *errstr;
122 #endif
123 
124 #ifdef CONFIG_PRINTK_INDEX
125 	printk_index_subsys_emit(
126 		"BTRFS: error (device %s%s) in %s:%d: errno=%d %s", KERN_CRIT, fmt);
127 #endif
128 
129 	/*
130 	 * Special case: if the error is EROFS, and we're already under
131 	 * SB_RDONLY, then it is safe here.
132 	 */
133 	if (error == -EROFS && sb_rdonly(sb))
134 		return;
135 
136 #ifdef CONFIG_PRINTK
137 	errstr = btrfs_decode_error(error);
138 	btrfs_state_to_string(fs_info, statestr);
139 	if (fmt) {
140 		struct va_format vaf;
141 		va_list args;
142 
143 		va_start(args, fmt);
144 		vaf.fmt = fmt;
145 		vaf.va = &args;
146 
147 		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s (%pV)\n",
148 			sb->s_id, statestr, function, line, error, errstr, &vaf);
149 		va_end(args);
150 	} else {
151 		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s\n",
152 			sb->s_id, statestr, function, line, error, errstr);
153 	}
154 #endif
155 
156 	/*
157 	 * Today we only save the error info to memory.  Long term we'll also
158 	 * send it down to the disk.
159 	 */
160 	WRITE_ONCE(fs_info->fs_error, error);
161 
162 	/* Don't go through full error handling during mount. */
163 	if (!(sb->s_flags & SB_BORN))
164 		return;
165 
166 	if (sb_rdonly(sb))
167 		return;
168 
169 	btrfs_discard_stop(fs_info);
170 
171 	/* Handle error by forcing the filesystem readonly. */
172 	btrfs_set_sb_rdonly(sb);
173 	btrfs_info(fs_info, "forced readonly");
174 	/*
175 	 * Note that a running device replace operation is not canceled here
176 	 * although there is no way to update the progress. It would add the
177 	 * risk of a deadlock, therefore the canceling is omitted. The only
178 	 * penalty is that some I/O remains active until the procedure
179 	 * completes. The next time when the filesystem is mounted writable
180 	 * again, the device replace operation continues.
181 	 */
182 }
183 
184 #ifdef CONFIG_PRINTK
185 static const char * const logtypes[] = {
186 	"emergency",
187 	"alert",
188 	"critical",
189 	"error",
190 	"warning",
191 	"notice",
192 	"info",
193 	"debug",
194 };
195 
196 /*
197  * Use one ratelimit state per log level so that a flood of less important
198  * messages doesn't cause more important ones to be dropped.
199  */
200 static struct ratelimit_state printk_limits[] = {
201 	RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
202 	RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
203 	RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
204 	RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
205 	RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
206 	RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
207 	RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
208 	RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
209 };
210 
211 void __cold _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
212 {
213 	char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
214 	struct va_format vaf;
215 	va_list args;
216 	int kern_level;
217 	const char *type = logtypes[4];
218 	struct ratelimit_state *ratelimit = &printk_limits[4];
219 
220 #ifdef CONFIG_PRINTK_INDEX
221 	printk_index_subsys_emit("%sBTRFS %s (device %s): ", NULL, fmt);
222 #endif
223 
224 	va_start(args, fmt);
225 
226 	while ((kern_level = printk_get_level(fmt)) != 0) {
227 		size_t size = printk_skip_level(fmt) - fmt;
228 
229 		if (kern_level >= '0' && kern_level <= '7') {
230 			memcpy(lvl, fmt,  size);
231 			lvl[size] = '\0';
232 			type = logtypes[kern_level - '0'];
233 			ratelimit = &printk_limits[kern_level - '0'];
234 		}
235 		fmt += size;
236 	}
237 
238 	vaf.fmt = fmt;
239 	vaf.va = &args;
240 
241 	if (__ratelimit(ratelimit)) {
242 		if (fs_info) {
243 			char statestr[STATE_STRING_BUF_LEN];
244 
245 			btrfs_state_to_string(fs_info, statestr);
246 			_printk("%sBTRFS %s (device %s%s): %pV\n", lvl, type,
247 				fs_info->sb->s_id, statestr, &vaf);
248 		} else {
249 			_printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
250 		}
251 	}
252 
253 	va_end(args);
254 }
255 #endif
256 
257 #if BITS_PER_LONG == 32
258 void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
259 {
260 	if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
261 		btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
262 		btrfs_warn(fs_info,
263 "due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
264 			   BTRFS_32BIT_MAX_FILE_SIZE >> 40);
265 		btrfs_warn(fs_info,
266 			   "please consider upgrading to 64bit kernel/hardware");
267 	}
268 }
269 
270 void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
271 {
272 	if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
273 		btrfs_err(fs_info, "reached 32bit limit for logical addresses");
274 		btrfs_err(fs_info,
275 "due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
276 			  BTRFS_32BIT_MAX_FILE_SIZE >> 40);
277 		btrfs_err(fs_info,
278 			   "please consider upgrading to 64bit kernel/hardware");
279 	}
280 }
281 #endif
282 
283 /*
284  * Decode unexpected, fatal errors from the caller, issue an alert, and either
285  * panic or BUGs, depending on mount options.
286  */
287 __cold
288 void __btrfs_panic(const struct btrfs_fs_info *fs_info, const char *function,
289 		   unsigned int line, int error, const char *fmt, ...)
290 {
291 	char *s_id = "<unknown>";
292 	const char *errstr;
293 	struct va_format vaf = { .fmt = fmt };
294 	va_list args;
295 
296 	if (fs_info)
297 		s_id = fs_info->sb->s_id;
298 
299 	va_start(args, fmt);
300 	vaf.va = &args;
301 
302 	errstr = btrfs_decode_error(error);
303 	if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
304 		panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
305 			s_id, function, line, &vaf, error, errstr);
306 
307 	btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
308 		   function, line, &vaf, error, errstr);
309 	va_end(args);
310 	/* Caller calls BUG() */
311 }
312