void complete_master_bio(struct drbd_conf *mdev,
struct bio_and_error *m)
{
trace_drbd_bio(mdev, "Rq", m->bio, 1, NULL);
bio_endio(m->bio, m->error);
dec_ap_bio(mdev);
}
STATIC int _drbd_md_sync_page_io(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev,
struct page *page, sector_t sector,
int rw, int size)
{
struct bio *bio;
struct drbd_md_io md_io;
int ok;
md_io.mdev = mdev;
init_completion(&md_io.event);
md_io.error = 0;
if ((rw & WRITE) && !test_bit(MD_NO_BARRIER, &mdev->flags))
rw |= DRBD_REQ_FUA | DRBD_REQ_FLUSH;
rw |= DRBD_REQ_UNPLUG | DRBD_REQ_SYNC;
#ifndef REQ_FLUSH
/* < 2.6.36, "barrier" semantic may fail with EOPNOTSUPP */
retry:
#endif
bio = bio_alloc(GFP_NOIO, 1);
bio->bi_bdev = bdev->md_bdev;
bio->bi_sector = sector;
ok = (bio_add_page(bio, page, size, 0) == size);
if (!ok)
goto out;
bio->bi_private = &md_io;
bio->bi_end_io = drbd_md_io_complete;
bio->bi_rw = rw;
trace_drbd_bio(mdev, "Md", bio, 0, NULL);
if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
bio_endio(bio, -EIO);
else
submit_bio(rw, bio);
wait_for_completion(&md_io.event);
ok = bio_flagged(bio, BIO_UPTODATE) && md_io.error == 0;
#ifndef REQ_FLUSH
/* check for unsupported barrier op.
* would rather check on EOPNOTSUPP, but that is not reliable.
* don't try again for ANY return value != 0 */
if (unlikely((bio->bi_rw & DRBD_REQ_HARDBARRIER) && !ok)) {
/* Try again with no barrier */
dev_warn(DEV, "Barriers not supported on meta data device - disabling\n");
set_bit(MD_NO_BARRIER, &mdev->flags);
rw &= ~DRBD_REQ_HARDBARRIER;
bio_put(bio);
goto retry;
}
#endif
out:
bio_put(bio);
return ok;
}
