Dave Chinner <david@xxxxxxxxxxxxx> writes: > You need the XFS patch I posted so that readahead buffer > verification is avoided in the case of an error being returned from > the readahead. I apologize if I was not clear in my previous post. I mean to say that returning -EIO from dm, even in conjunction with your patch, is not sufficient to fix the problem. Specifically, I repeated the experiment with v3.8.2 patched as discussed below, running my original script (repeated here for completeness): pvcreate /dev/vd[bc] vgcreate test /dev/vd[bc] lvcreate -L 8G -n vol test /dev/vdb mkfs.xfs -f /dev/mapper/test-vol mount -o noatime /dev/mapper/test-vol /mnt cd /mnt git clone ~/linux-stable cd / umount /mnt mount -o noatime /dev/mapper/test-vol /mnt pvmove -b /dev/vdb /dev/vdc sleep 2 rm -rf /mnt/linux-stable I obtained a string of errors that starts with this: [ 166.596574] XFS (dm-1): metadata I/O error: block 0x805060 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.599556] XFS (dm-1): metadata I/O error: block 0x805060 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.604845] XFS (dm-1): metadata I/O error: block 0x5285b8 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.607894] XFS (dm-1): metadata I/O error: block 0x5285b8 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.614242] XFS (dm-1): metadata I/O error: block 0x54f2b0 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.617307] XFS (dm-1): metadata I/O error: block 0x54f2b0 ("xfs_trans_read_buf_map") error 5 numblks 8 [ 166.651373] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.653517] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.655545] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.657614] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.659685] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.661731] XFS (dm-1): Corruption detected. Unmount and run xfs_repair [ 166.663761] XFS (dm-1): Corruption detected. Unmount and run xfs_repair I used v3.8.2 with the following diff, including both your xfs patch and my attempt to patch dm-raid1 to return EIO: diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index fa51918..88903e3 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -1169,7 +1169,7 @@ static int mirror_map(struct dm_target *ti, struct bio *bio) */ if (!r || (r == -EWOULDBLOCK)) { if (rw == READA) - return -EWOULDBLOCK; + return -EIO; queue_bio(ms, bio, rw); return DM_MAPIO_SUBMITTED; diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index fbbb9eb..c961dd4 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1024,7 +1024,9 @@ xfs_buf_iodone_work( bool read = !!(bp->b_flags & XBF_READ); bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD); - if (read && bp->b_ops) + + /* only validate buffers that were read without errors */ + if (read && bp->b_ops && !bp->b_error && (bp->b_flags & XBF_DONE)) bp->b_ops->verify_read(bp); if (bp->b_iodone) So your patch is not sufficient to fix the problem, even if dm returns -EIO instead of -EAGAIN. My question is, what is dm supposed to return? Regards, MF -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel