Commit ae3364e5 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: store the error that turned the fs into error state 



Currently when we turn the fs into an error state, typically after a
transaction abort, we don't store the error anywhere, we just set a bit
(BTRFS_FS_STATE_ERROR) at struct btrfs_fs_info::fs_state to signal the
error state.

There are cases where it would be useful to have access to the specific
error in order to provide a more meaningful error to users/applications.
This change adds a member to struct btrfs_fs_info to store the error and
removes the BTRFS_FS_STATE_ERROR bit. When there's no error, the new
member (fs_error) has a value of 0, otherwise its value is a negative
errno value.

Followup changes will make use of this new member.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 1b6948ac

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -3222,7 +3222,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device 


	/* check FS state, whether FS is broken. */

	if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)

		set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);

		WRITE_ONCE(fs_info->fs_error, -EUCLEAN);



	/*

	 * In the long term, we'll store the compression type in the super

fs/btrfs/fs.h

+8 −4
Original line number Diff line number Diff line
@@ -46,8 +46,6 @@ static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE); 
 * Runtime (in-memory) states of filesystem

 */

enum {

	/* Global indicator of serious filesystem errors */

	BTRFS_FS_STATE_ERROR,

	/*

	 * Filesystem is being remounted, allow to skip some operations, like

	 * defrag
@@ -686,6 +684,12 @@ struct btrfs_fs_info { 
	bool qgroup_rescan_running;

	u8 qgroup_drop_subtree_thres;



	/*

	 * If this is not 0, then it indicates a serious filesystem error has

	 * happened and it contains that error (negative errno value).

	 */

	int fs_error;



	/* Filesystem state */

	unsigned long fs_state;
@@ -962,8 +966,8 @@ static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info) 
	clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);

}



#define BTRFS_FS_ERROR(fs_info)	(unlikely(test_bit(BTRFS_FS_STATE_ERROR, \

						   &(fs_info)->fs_state)))

#define BTRFS_FS_ERROR(fs_info)	(READ_ONCE((fs_info)->fs_error))



#define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info)				\

	(unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,		\

			   &(fs_info)->fs_state)))

fs/btrfs/messages.c

+7 −3
Original line number Diff line number Diff line
@@ -10,14 +10,13 @@ 
#ifdef CONFIG_PRINTK



#define STATE_STRING_PREFACE	": state "

#define STATE_STRING_BUF_LEN	(sizeof(STATE_STRING_PREFACE) + BTRFS_FS_STATE_COUNT)

#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_ERROR]			= 'E',

	[BTRFS_FS_STATE_REMOUNTING]		= 'M',

	[BTRFS_FS_STATE_RO]			= 0,

	[BTRFS_FS_STATE_TRANS_ABORTED]		= 'A',
@@ -37,6 +36,11 @@ static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *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]) {
@@ -155,7 +159,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function 
	 * Today we only save the error info to memory.  Long term we'll also

	 * send it down to the disk.

	 */

	set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);

	WRITE_ONCE(fs_info->fs_error, errno);



	/* Don't go through full error handling during mount. */

	if (!(sb->s_flags & SB_BORN))