fs/btrfs/messages.c

   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
  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  */
  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
 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
 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         /* Do not ratelimit if CONFIG_BTRFS_DEBUG is enabled. */
 243         if (IS_ENABLED(CONFIG_BTRFS_DEBUG) || __ratelimit(ratelimit)) {
 244                 if (fs_info) {
 245                         char statestr[STATE_STRING_BUF_LEN];
 246
 247                         btrfs_state_to_string(fs_info, statestr);
 248                         _printk("%sBTRFS %s (device %s%s): %pV\n", lvl, type,
 249                                 fs_info->sb->s_id, statestr, &vaf);
 250                 } else {
 251                         _printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
 252                 }
 253         }
 254
 255         va_end(args);
 256 }
 257 #endif
 258
 259 #if BITS_PER_LONG == 32
 260 void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
 261 {
 262         if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
 263                 btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
 264                 btrfs_warn(fs_info,
 265 "due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
 266                            BTRFS_32BIT_MAX_FILE_SIZE >> 40);
 267                 btrfs_warn(fs_info,
 268                            "please consider upgrading to 64bit kernel/hardware");
 269         }
 270 }
 271
 272 void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
 273 {
 274         if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
 275                 btrfs_err(fs_info, "reached 32bit limit for logical addresses");
 276                 btrfs_err(fs_info,
 277 "due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
 278                           BTRFS_32BIT_MAX_FILE_SIZE >> 40);
 279                 btrfs_err(fs_info,
 280                            "please consider upgrading to 64bit kernel/hardware");
 281         }
 282 }
 283 #endif
 284
 285 /*
 286  * Decode unexpected, fatal errors from the caller, issue an alert, and either
 287  * panic or BUGs, depending on mount options.
 288  */
 289 __cold
 290 void __btrfs_panic(const struct btrfs_fs_info *fs_info, const char *function,
 291                    unsigned int line, int error, const char *fmt, ...)
 292 {
 293         char *s_id = "<unknown>";
 294         const char *errstr;
 295         struct va_format vaf = { .fmt = fmt };
 296         va_list args;
 297
 298         if (fs_info)
 299                 s_id = fs_info->sb->s_id;
 300
 301         va_start(args, fmt);
 302         vaf.va = &args;
 303
 304         errstr = btrfs_decode_error(error);
 305         if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
 306                 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 307                         s_id, function, line, &vaf, error, errstr);
 308
 309         btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
 310                    function, line, &vaf, error, errstr);
 311         va_end(args);
 312         /* Caller calls BUG() */
 313 }