Commit c067da87 authored by Sweet Tea Dorminy's avatar Sweet Tea Dorminy Committed by David Sterba
Browse files

btrfs: add filesystems state details to error messages 



When a filesystem goes read-only due to an error, multiple errors tend
to be reported, some of which are knock-on failures. Logging fs_states,
in btrfs_handle_fs_error() and btrfs_printk() helps distinguish the
first error from subsequent messages which may only exist due to an
error state.

Under the new format, most initial errors will look like:
`BTRFS: error (device loop0) in ...`
while subsequent errors will begin with:
`error (device loop0: state E) in ...`

An initial transaction abort error will look like
`error (device loop0: state A) in ...`
and subsequent messages will contain
`(device loop0: state EA) in ...`

In addition to the error states we can also print other states that are
temporary, like remounting, device replace, or indicate a global state
that may affect functionality.

Now implemented:

E - filesystem error detected
A - transaction aborted
L - log tree errors

M - remounting in progress
R - device replace in progress
C - data checksums not verified (mounted with ignoredatacsums)

Signed-off-by: default avatarSweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent b2d9f2dc

fs/btrfs/ctree.h

+2 −0
Original line number Diff line number Diff line
@@ -149,6 +149,8 @@ enum { 


	/* Indicates there was an error cleaning up a log tree. */

	BTRFS_FS_STATE_LOG_CLEANUP_ERROR,



	BTRFS_FS_STATE_COUNT

};



#define BTRFS_BACKREF_REV_MAX		256

fs/btrfs/super.c

+60 −8
Original line number Diff line number Diff line
@@ -66,6 +66,52 @@ static struct file_system_type btrfs_root_fs_type; 


static int btrfs_remount(struct super_block *sb, int *flags, char *data);



#ifdef CONFIG_PRINTK



#define STATE_STRING_PREFACE	": state "

#define STATE_STRING_BUF_LEN	(sizeof(STATE_STRING_PREFACE) + BTRFS_FS_STATE_COUNT)



/*

 * Characters to print to indicate error conditions or uncommon filesystem sate.

 * RO is not an error.

 */

static const char fs_state_chars[] = {

	[BTRFS_FS_STATE_ERROR]			= 'E',

	[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;



	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.
@@ -128,6 +174,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function 
{

	struct super_block *sb = fs_info->sb;

#ifdef CONFIG_PRINTK

	char statestr[STATE_STRING_BUF_LEN];

	const char *errstr;

#endif
@@ -140,6 +187,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function 


#ifdef CONFIG_PRINTK

	errstr = btrfs_decode_error(errno);

	btrfs_state_to_string(fs_info, statestr);

	if (fmt) {

		struct va_format vaf;

		va_list args;
@@ -148,12 +196,12 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function 
		vaf.fmt = fmt;

		vaf.va = &args;



		pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",

			sb->s_id, function, line, errno, errstr, &vaf);

		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) in %s:%d: errno=%d %s\n",

			sb->s_id, function, line, errno, errstr);

		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s\n",

			sb->s_id, statestr, function, line, errno, errstr);

	}

#endif
@@ -240,12 +288,16 @@ void __cold btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, . 
	vaf.va = &args;



	if (__ratelimit(ratelimit)) {

		if (fs_info)

			printk("%sBTRFS %s (device %s): %pV\n", lvl, type,

				fs_info->sb->s_id, &vaf);

		else

		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);

}