1 files changed, 313 insertions, 0 deletions
diff --git a/fs/btrfs/messages.c b/fs/btrfs/messages.c
new file mode 100644
index 000000000..7695decc7
--- /dev/null
+++ b/fs/btrfs/messages.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "fs.h"
+#include "messages.h"
+#include "discard.h"
+#include "transaction.h"
+#include "space-info.h"
+#include "super.h"
+
+#ifdef CONFIG_PRINTK
+
+#define STATE_STRING_PREFACE	": state "
+#define STATE_STRING_BUF_LEN	(sizeof(STATE_STRING_PREFACE) + BTRFS_FS_STATE_COUNT + 1)
+
+/*
+ * Characters to print to indicate error conditions or uncommon filesystem state.
+ * RO is not an error.
+ */
+static const char fs_state_chars[] = {
+	[BTRFS_FS_STATE_REMOUNTING]		= 'M',
+	[BTRFS_FS_STATE_RO]			= 0,
+	[BTRFS_FS_STATE_TRANS_ABORTED]		= 'A',
+	[BTRFS_FS_STATE_DEV_REPLACING]		= 'R',
+	[BTRFS_FS_STATE_DUMMY_FS_INFO]		= 0,
+	[BTRFS_FS_STATE_NO_CSUMS]		= 'C',
+	[BTRFS_FS_STATE_LOG_CLEANUP_ERROR]	= 'L',
+};
+
+static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *buf)
+{
+	unsigned int bit;
+	bool states_printed = false;
+	unsigned long fs_state = READ_ONCE(info->fs_state);
+	char *curr = buf;
+
+	memcpy(curr, STATE_STRING_PREFACE, sizeof(STATE_STRING_PREFACE));
+	curr += sizeof(STATE_STRING_PREFACE) - 1;
+
+	if (BTRFS_FS_ERROR(info)) {
+		*curr++ = 'E';
+		states_printed = true;
+	}
+
+	for_each_set_bit(bit, &fs_state, sizeof(fs_state)) {
+		WARN_ON_ONCE(bit >= BTRFS_FS_STATE_COUNT);
+		if ((bit < BTRFS_FS_STATE_COUNT) && fs_state_chars[bit]) {
+			*curr++ = fs_state_chars[bit];
+			states_printed = true;
+		}
+	}
+
+	/* If no states were printed, reset the buffer */
+	if (!states_printed)
+		curr = buf;
+
+	*curr++ = 0;
+}
+#endif
+
+/*
+ * Generally the error codes correspond to their respective errors, but there
+ * are a few special cases.
+ *
+ * EUCLEAN: Any sort of corruption that we encounter.  The tree-checker for
+ *          instance will return EUCLEAN if any of the blocks are corrupted in
+ *          a way that is problematic.  We want to reserve EUCLEAN for these
+ *          sort of corruptions.
+ *
+ * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we
+ *        need to use EROFS for this case.  We will have no idea of the
+ *        original failure, that will have been reported at the time we tripped
+ *        over the error.  Each subsequent error that doesn't have any context
+ *        of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR.
+ */
+const char * __attribute_const__ btrfs_decode_error(int errno)
+{
+	char *errstr = "unknown";
+
+	switch (errno) {
+	case -ENOENT:		/* -2 */
+		errstr = "No such entry";
+		break;
+	case -EIO:		/* -5 */
+		errstr = "IO failure";
+		break;
+	case -ENOMEM:		/* -12*/
+		errstr = "Out of memory";
+		break;
+	case -EEXIST:		/* -17 */
+		errstr = "Object already exists";
+		break;
+	case -ENOSPC:		/* -28 */
+		errstr = "No space left";
+		break;
+	case -EROFS:		/* -30 */
+		errstr = "Readonly filesystem";
+		break;
+	case -EOPNOTSUPP:	/* -95 */
+		errstr = "Operation not supported";
+		break;
+	case -EUCLEAN:		/* -117 */
+		errstr = "Filesystem corrupted";
+		break;
+	case -EDQUOT:		/* -122 */
+		errstr = "Quota exceeded";
+		break;
+	}
+
+	return errstr;
+}
+
+/*
+ * __btrfs_handle_fs_error decodes expected errors from the caller and
+ * invokes the appropriate error response.
+ */
+__cold
+void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function,
+		       unsigned int line, int errno, const char *fmt, ...)
+{
+	struct super_block *sb = fs_info->sb;
+#ifdef CONFIG_PRINTK
+	char statestr[STATE_STRING_BUF_LEN];
+	const char *errstr;
+#endif
+
+#ifdef CONFIG_PRINTK_INDEX
+	printk_index_subsys_emit(
+		"BTRFS: error (device %s%s) in %s:%d: errno=%d %s", KERN_CRIT, fmt);
+#endif
+
+	/*
+	 * Special case: if the error is EROFS, and we're already under
+	 * SB_RDONLY, then it is safe here.
+	 */
+	if (errno == -EROFS && sb_rdonly(sb))
+		return;
+
+#ifdef CONFIG_PRINTK
+	errstr = btrfs_decode_error(errno);
+	btrfs_state_to_string(fs_info, statestr);
+	if (fmt) {
+		struct va_format vaf;
+		va_list args;
+
+		va_start(args, fmt);
+		vaf.fmt = fmt;
+		vaf.va = &args;
+
+		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s (%pV)\n",
+			sb->s_id, statestr, function, line, errno, errstr, &vaf);
+		va_end(args);
+	} else {
+		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s\n",
+			sb->s_id, statestr, function, line, errno, errstr);
+	}
+#endif
+
+	/*
+	 * Today we only save the error info to memory.  Long term we'll also
+	 * send it down to the disk.
+	 */
+	WRITE_ONCE(fs_info->fs_error, errno);
+
+	/* Don't go through full error handling during mount. */
+	if (!(sb->s_flags & SB_BORN))
+		return;
+
+	if (sb_rdonly(sb))
+		return;
+
+	btrfs_discard_stop(fs_info);
+
+	/* Handle error by forcing the filesystem readonly. */
+	btrfs_set_sb_rdonly(sb);
+	btrfs_info(fs_info, "forced readonly");
+	/*
+	 * Note that a running device replace operation is not canceled here
+	 * although there is no way to update the progress. It would add the
+	 * risk of a deadlock, therefore the canceling is omitted. The only
+	 * penalty is that some I/O remains active until the procedure
+	 * completes. The next time when the filesystem is mounted writable
+	 * again, the device replace operation continues.
+	 */
+}
+
+#ifdef CONFIG_PRINTK
+static const char * const logtypes[] = {
+	"emergency",
+	"alert",
+	"critical",
+	"error",
+	"warning",
+	"notice",
+	"info",
+	"debug",
+};
+
+/*
+ * Use one ratelimit state per log level so that a flood of less important
+ * messages doesn't cause more important ones to be dropped.
+ */
+static struct ratelimit_state printk_limits[] = {
+	RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
+	RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
+};
+
+void __cold _btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
+{
+	char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
+	struct va_format vaf;
+	va_list args;
+	int kern_level;
+	const char *type = logtypes[4];
+	struct ratelimit_state *ratelimit = &printk_limits[4];
+
+#ifdef CONFIG_PRINTK_INDEX
+	printk_index_subsys_emit("%sBTRFS %s (device %s): ", NULL, fmt);
+#endif
+
+	va_start(args, fmt);
+
+	while ((kern_level = printk_get_level(fmt)) != 0) {
+		size_t size = printk_skip_level(fmt) - fmt;
+
+		if (kern_level >= '0' && kern_level <= '7') {
+			memcpy(lvl, fmt,  size);
+			lvl[size] = '\0';
+			type = logtypes[kern_level - '0'];
+			ratelimit = &printk_limits[kern_level - '0'];
+		}
+		fmt += size;
+	}
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	if (__ratelimit(ratelimit)) {
+		if (fs_info) {
+			char statestr[STATE_STRING_BUF_LEN];
+
+			btrfs_state_to_string(fs_info, statestr);
+			_printk("%sBTRFS %s (device %s%s): %pV\n", lvl, type,
+				fs_info->sb->s_id, statestr, &vaf);
+		} else {
+			_printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
+		}
+	}
+
+	va_end(args);
+}
+#endif
+
+#if BITS_PER_LONG == 32
+void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info)
+{
+	if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) {
+		btrfs_warn(fs_info, "reaching 32bit limit for logical addresses");
+		btrfs_warn(fs_info,
+"due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT",
+			   BTRFS_32BIT_MAX_FILE_SIZE >> 40);
+		btrfs_warn(fs_info,
+			   "please consider upgrading to 64bit kernel/hardware");
+	}
+}
+
+void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info)
+{
+	if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) {
+		btrfs_err(fs_info, "reached 32bit limit for logical addresses");
+		btrfs_err(fs_info,
+"due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed",
+			  BTRFS_32BIT_MAX_FILE_SIZE >> 40);
+		btrfs_err(fs_info,
+			   "please consider upgrading to 64bit kernel/hardware");
+	}
+}
+#endif
+
+/*
+ * __btrfs_panic decodes unexpected, fatal errors from the caller, issues an
+ * alert, and either panics or BUGs, depending on mount options.
+ */
+__cold
+void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
+		   unsigned int line, int errno, const char *fmt, ...)
+{
+	char *s_id = "<unknown>";
+	const char *errstr;
+	struct va_format vaf = { .fmt = fmt };
+	va_list args;
+
+	if (fs_info)
+		s_id = fs_info->sb->s_id;
+
+	va_start(args, fmt);
+	vaf.va = &args;
+
+	errstr = btrfs_decode_error(errno);
+	if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR)))
+		panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
+			s_id, function, line, &vaf, errno, errstr);
+
+	btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
+		   function, line, &vaf, errno, errstr);
+	va_end(args);
+	/* Caller calls BUG() */
+}