Patch "btrfs: Reset IO error counters before start of device replacing" has been added to the 4.5-stable tree

This is a note to let you know that I've just added the patch titled

btrfs: Reset IO error counters before start of device replacing

to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
btrfs-reset-io-error-counters-before-start-of-device-replacing.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Yauhen Kharuzhy <[email protected]>
Date: Tue, 29 Mar 2016 14:17:48 -0700
Subject: btrfs: Reset IO error counters before start of device replacing

From: Yauhen Kharuzhy <[email protected]>

commit 7ccefb98ce3e5c4493cd213cd03714b7149cf0cb upstream.

If device replace entry was found on disk at mounting and its num_write_errors stats counter has non-NULL value, then replace operation will never be finished and -EIO error will be reported by btrfs_scrub_dev() because this counter is never reset.

 # mount -o degraded /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 # btrfs replace status /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 Started on 25.Mar 07:28:00, canceled on 25.Mar 07:28:01 at 0.0%, 40 write errs, 0 uncorr. read errs
 # btrfs replace start -B 4 /dev/sdg /media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/
 ERROR: ioctl(DEV_REPLACE_START) failed on "/media/a4fb5c0a-21c5-4fe7-8d0e-fdd87d5f71ee/": Input/output error, no error

Reset num_write_errors and num_uncorrectable_read_errors counters in the dev_replace structure before start of replacing.

---
 fs/btrfs/dev-replace.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -394,6 +394,8 @@ int btrfs_dev_replace_start(struct btrfs
 	dev_replace->cursor_right = 0;
 	dev_replace->is_valid = 1;
 	dev_replace->item_needs_writeback = 1;
+	atomic64_set(&dev_replace->num_write_errors, 0);
+	atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);
 	args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
 	btrfs_dev_replace_unlock(dev_replace);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.5/btrfs-reset-io-error-counters-before-start-of-device-replacing.patch