Commit 1979dbbe authored by Li Nan's avatar Li Nan Committed by Song Liu
Browse files

md: factor out a helper exceed_read_errors() to check read_errors 



Move check_decay_read_errors() to raid1-10.c and factor out a helper
exceed_read_errors() to check if read_errors exceeds the limit, so that
raid1 can also use it. There are no functional changes.

Signed-off-by: default avatarLi Nan <linan122@huawei.com>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231215023852.3478228-2-linan666@huaweicloud.com
parent dc1cc22e

drivers/md/raid1-10.c

+54 −0
Original line number Diff line number Diff line
@@ -173,3 +173,57 @@ static inline void raid1_prepare_flush_writes(struct bitmap *bitmap) 
	else

		md_bitmap_unplug(bitmap);

}



/*

 * Used by fix_read_error() to decay the per rdev read_errors.

 * We halve the read error count for every hour that has elapsed

 * since the last recorded read error.

 */

static inline void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)

{

	long cur_time_mon;

	unsigned long hours_since_last;

	unsigned int read_errors = atomic_read(&rdev->read_errors);



	cur_time_mon = ktime_get_seconds();



	if (rdev->last_read_error == 0) {

		/* first time we've seen a read error */

		rdev->last_read_error = cur_time_mon;

		return;

	}



	hours_since_last = (long)(cur_time_mon -

			    rdev->last_read_error) / 3600;



	rdev->last_read_error = cur_time_mon;



	/*

	 * if hours_since_last is > the number of bits in read_errors

	 * just set read errors to 0. We do this to avoid

	 * overflowing the shift of read_errors by hours_since_last.

	 */

	if (hours_since_last >= 8 * sizeof(read_errors))

		atomic_set(&rdev->read_errors, 0);

	else

		atomic_set(&rdev->read_errors, read_errors >> hours_since_last);

}



static inline bool exceed_read_errors(struct mddev *mddev, struct md_rdev *rdev)

{

	int max_read_errors = atomic_read(&mddev->max_corr_read_errors);

	int read_errors;



	check_decay_read_errors(mddev, rdev);

	read_errors =  atomic_inc_return(&rdev->read_errors);

	if (read_errors > max_read_errors) {

		pr_notice("md/"RAID_1_10_NAME":%s: %pg: Raid device exceeded read_error threshold [cur %d:max %d]\n",

			  mdname(mddev), rdev->bdev, read_errors, max_read_errors);

		pr_notice("md/"RAID_1_10_NAME":%s: %pg: Failing raid device\n",

			  mdname(mddev), rdev->bdev);

		md_error(mddev, rdev);

		return true;

	}



	return false;

}

drivers/md/raid1.c

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ static void lower_barrier(struct r1conf *conf, sector_t sector_nr); 
#define raid1_log(md, fmt, args...)				\

	do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)



#define RAID_1_10_NAME "raid1"

#include "raid1-10.c"



#define START(node) ((node)->start)

drivers/md/raid10.c

+3 −46
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#include <linux/raid/md_p.h>

#include <trace/events/block.h>

#include "md.h"



#define RAID_1_10_NAME "raid10"

#include "raid10.h"

#include "raid0.h"

#include "md-bitmap.h"
@@ -2592,42 +2594,6 @@ static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio) 
	}

}



/*

 * Used by fix_read_error() to decay the per rdev read_errors.

 * We halve the read error count for every hour that has elapsed

 * since the last recorded read error.

 *

 */

static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)

{

	long cur_time_mon;

	unsigned long hours_since_last;

	unsigned int read_errors = atomic_read(&rdev->read_errors);



	cur_time_mon = ktime_get_seconds();



	if (rdev->last_read_error == 0) {

		/* first time we've seen a read error */

		rdev->last_read_error = cur_time_mon;

		return;

	}



	hours_since_last = (long)(cur_time_mon -

			    rdev->last_read_error) / 3600;



	rdev->last_read_error = cur_time_mon;



	/*

	 * if hours_since_last is > the number of bits in read_errors

	 * just set read errors to 0. We do this to avoid

	 * overflowing the shift of read_errors by hours_since_last.

	 */

	if (hours_since_last >= 8 * sizeof(read_errors))

		atomic_set(&rdev->read_errors, 0);

	else

		atomic_set(&rdev->read_errors, read_errors >> hours_since_last);

}



static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,

			    int sectors, struct page *page, enum req_op op)

{
@@ -2665,7 +2631,6 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 
	int sect = 0; /* Offset from r10_bio->sector */

	int sectors = r10_bio->sectors, slot = r10_bio->read_slot;

	struct md_rdev *rdev;

	int max_read_errors = atomic_read(&mddev->max_corr_read_errors);

	int d = r10_bio->devs[slot].devnum;



	/* still own a reference to this rdev, so it cannot
@@ -2678,15 +2643,7 @@ static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10 
		   more fix_read_error() attempts */

		return;



	check_decay_read_errors(mddev, rdev);

	atomic_inc(&rdev->read_errors);

	if (atomic_read(&rdev->read_errors) > max_read_errors) {

		pr_notice("md/raid10:%s: %pg: Raid device exceeded read_error threshold [cur %d:max %d]\n",

			  mdname(mddev), rdev->bdev,

			  atomic_read(&rdev->read_errors), max_read_errors);

		pr_notice("md/raid10:%s: %pg: Failing raid device\n",

			  mdname(mddev), rdev->bdev);

		md_error(mddev, rdev);

	if (exceed_read_errors(mddev, rdev)) {

		r10_bio->devs[slot].bio = IO_BLOCKED;

		return;

	}