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| author | Anand Jain <anand.jain@oracle.com> | 2017-10-14 08:34:02 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-20 10:10:30 +0100 |
| commit | 4bcbfac98d517eae6d12257aed923347be16930c (patch) | |
| tree | 3ddaf9b9269a6583627020509a35f65c1a206ff0 | |
| parent | 7bd6bf08dd5b30dbe0696a7387dedc65a5f9a3e6 (diff) | |
| download | linux-stable-4bcbfac98d517eae6d12257aed923347be16930c.tar.gz linux-stable-4bcbfac98d517eae6d12257aed923347be16930c.tar.bz2 linux-stable-4bcbfac98d517eae6d12257aed923347be16930c.zip | |
btrfs: fix false EIO for missing device
[ Upstream commit 102ed2c5ff932439bbbe74c7bd63e6d5baa9f732 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/volumes.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b39737568c22..abc57f7b2716 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6144,7 +6144,10 @@ 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); } } |