btrfs: submit superblock io with REQ_META and REQ_PRIO

The superblock is also metadata of the filesystem so the relevant IO
should be tagged as such. We also tag it as high priority, as it's the
last block committed for metadata from a given transaction. Any delays
would effectively block the whole transaction, also blocking any other
operation holding the device_list_mutex.

Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2017-08-18 18:16:25 +02:00
parent dc59215d4f
commit db95c876c5

View file

@ -3433,9 +3433,10 @@ static int write_dev_supers(struct btrfs_device *device,
*/
if (i == 0) {
ret = btrfsic_submit_bh(REQ_OP_WRITE,
REQ_SYNC | REQ_FUA, bh);
REQ_SYNC | REQ_FUA | REQ_META | REQ_PRIO, bh);
} else {
ret = btrfsic_submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
ret = btrfsic_submit_bh(REQ_OP_WRITE,
REQ_SYNC | REQ_META | REQ_PRIO, bh);
}
if (ret)
errors++;