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authorAnand Jain <anand.jain@oracle.com>2017-10-14 08:34:02 +0800
committerDavid Sterba <dsterba@suse.com>2017-10-30 12:28:01 +0100
commit102ed2c5ff932439bbbe74c7bd63e6d5baa9f732 (patch)
tree3ed87b2dd40cc5d05dcec274e882784d926cabbf /fs/btrfs
parentde48373454aceaf65877f9953eaf942505e83cc5 (diff)
downloadlinux-102ed2c5ff932439bbbe74c7bd63e6d5baa9f732.tar.bz2
btrfs: fix false EIO for missing device
When one of the device is missing, bbio_error() takes care of setting the error status. And if its only IO that is pending in that stripe, it fails to check the status of the other IO at %bbio_error before setting the error %bi_status for the %orig_bio. Fix this by checking if %bbio->error has exceeded the %bbio->max_errors. Reproducer as below fdatasync error is seen intermittently. mount -o degraded /dev/sdc /btrfs dd status=none if=/dev/zero of=$(mktemp /btrfs/XXX) bs=4096 count=1 conv=fdatasync dd: fdatasync failed for ‘/btrfs/LSe’: Input/output error The reason for the intermittences of the problem is because the following conditions have to be met, which depends on timing: In btrfs_map_bio() - the RAID1 the missing device has to be at %dev_nr = 1 In bbio_error() . before bbio_error() is called the bio of the not-missing device at %dev_nr = 0 must be completed so that the below condition is true if (atomic_dec_and_test(&bbio->stripes_pending)) { Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/volumes.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6df39b5fda89..11d7707a3fb3 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6129,7 +6129,10 @@ static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
bio->bi_iter.bi_sector = logical >> 9;
- bio->bi_status = BLK_STS_IOERR;
+ if (atomic_read(&bbio->error) > bbio->max_errors)
+ bio->bi_status = BLK_STS_IOERR;
+ else
+ bio->bi_status = BLK_STS_OK;
btrfs_end_bbio(bbio, bio);
}
}