Commit 8b110e39 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: implement repair function when direct read fails 



This patch implement data repair function when direct read fails.

The detail of the implementation is:
- When we find the data is not right, we try to read the data from the other
  mirror.
- When the io on the mirror ends, we will insert the endio work into the
  dedicated btrfs workqueue, not common read endio workqueue, because the
  original endio work is still blocked in the btrfs endio workqueue, if we
  insert the endio work of the io on the mirror into that workqueue, deadlock
  would happen.
- After we get right data, we write it back to the corrupted mirror.
- And if the data on the new mirror is still corrupted, we will try next
  mirror until we read right data or all the mirrors are traversed.
- After the above work, we set the uptodate flag according to the result.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 28e1cc7d

fs/btrfs/async-thread.c

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ BTRFS_WORK_HELPER(endio_helper); 
BTRFS_WORK_HELPER(endio_meta_helper);

BTRFS_WORK_HELPER(endio_meta_write_helper);

BTRFS_WORK_HELPER(endio_raid56_helper);

BTRFS_WORK_HELPER(endio_repair_helper);

BTRFS_WORK_HELPER(rmw_helper);

BTRFS_WORK_HELPER(endio_write_helper);

BTRFS_WORK_HELPER(freespace_write_helper);

fs/btrfs/async-thread.h

+1 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ BTRFS_WORK_HELPER_PROTO(endio_helper); 
BTRFS_WORK_HELPER_PROTO(endio_meta_helper);

BTRFS_WORK_HELPER_PROTO(endio_meta_write_helper);

BTRFS_WORK_HELPER_PROTO(endio_raid56_helper);

BTRFS_WORK_HELPER_PROTO(endio_repair_helper);

BTRFS_WORK_HELPER_PROTO(rmw_helper);

BTRFS_WORK_HELPER_PROTO(endio_write_helper);

BTRFS_WORK_HELPER_PROTO(freespace_write_helper);

fs/btrfs/btrfs_inode.h

+1 −1
Original line number Diff line number Diff line
@@ -271,7 +271,7 @@ struct btrfs_dio_private { 
	 * The original bio may be splited to several sub-bios, this is

	 * done during endio of sub-bios

	 */

	int (*subio_endio)(struct inode *, struct btrfs_io_bio *);

	int (*subio_endio)(struct inode *, struct btrfs_io_bio *, int);

};



/*

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -1538,6 +1538,7 @@ struct btrfs_fs_info { 
	struct btrfs_workqueue *endio_workers;

	struct btrfs_workqueue *endio_meta_workers;

	struct btrfs_workqueue *endio_raid56_workers;

	struct btrfs_workqueue *endio_repair_workers;

	struct btrfs_workqueue *rmw_workers;

	struct btrfs_workqueue *endio_meta_write_workers;

	struct btrfs_workqueue *endio_write_workers;

fs/btrfs/disk-io.c

+10 −1
Original line number Diff line number Diff line
@@ -713,7 +713,11 @@ static void end_workqueue_bio(struct bio *bio, int err) 
			func = btrfs_endio_write_helper;

		}

	} else {

		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {

		if (unlikely(end_io_wq->metadata ==

			     BTRFS_WQ_ENDIO_DIO_REPAIR)) {

			wq = fs_info->endio_repair_workers;

			func = btrfs_endio_repair_helper;

		} else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56) {

			wq = fs_info->endio_raid56_workers;

			func = btrfs_endio_raid56_helper;

		} else if (end_io_wq->metadata) {
@@ -741,6 +745,7 @@ int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio, 
			int metadata)

{

	struct end_io_wq *end_io_wq;



	end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);

	if (!end_io_wq)

		return -ENOMEM;
@@ -2055,6 +2060,7 @@ static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info) 
	btrfs_destroy_workqueue(fs_info->endio_workers);

	btrfs_destroy_workqueue(fs_info->endio_meta_workers);

	btrfs_destroy_workqueue(fs_info->endio_raid56_workers);

	btrfs_destroy_workqueue(fs_info->endio_repair_workers);

	btrfs_destroy_workqueue(fs_info->rmw_workers);

	btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);

	btrfs_destroy_workqueue(fs_info->endio_write_workers);
@@ -2572,6 +2578,8 @@ int open_ctree(struct super_block *sb, 
		btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);

	fs_info->endio_raid56_workers =

		btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);

	fs_info->endio_repair_workers =

		btrfs_alloc_workqueue("endio-repair", flags, 1, 0);

	fs_info->rmw_workers =

		btrfs_alloc_workqueue("rmw", flags, max_active, 2);

	fs_info->endio_write_workers =
@@ -2593,6 +2601,7 @@ int open_ctree(struct super_block *sb, 
	      fs_info->submit_workers && fs_info->flush_workers &&

	      fs_info->endio_workers && fs_info->endio_meta_workers &&

	      fs_info->endio_meta_write_workers &&

	      fs_info->endio_repair_workers &&

	      fs_info->endio_write_workers && fs_info->endio_raid56_workers &&

	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&

	      fs_info->caching_workers && fs_info->readahead_workers &&

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