drbd: REQ_HARDBARRIER -> REQ_FUA transition for meta data accesses

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Philipp Reisner 2010-08-25 10:21:04 +02:00
parent 2451fc3b2b
commit a8a4e51e69
3 changed files with 7 additions and 20 deletions

View File

@ -78,11 +78,10 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
init_completion(&md_io.event);
md_io.error = 0;
if ((rw & WRITE) && !test_bit(MD_NO_BARRIER, &mdev->flags))
rw |= REQ_HARDBARRIER;
if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
rw |= REQ_FUA;
rw |= REQ_UNPLUG | REQ_SYNC;
retry:
bio = bio_alloc(GFP_NOIO, 1);
bio->bi_bdev = bdev->md_bdev;
bio->bi_sector = sector;
@ -100,17 +99,6 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
wait_for_completion(&md_io.event);
ok = bio_flagged(bio, BIO_UPTODATE) && md_io.error == 0;
/* 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 & 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 &= ~REQ_HARDBARRIER;
bio_put(bio);
goto retry;
}
out:
bio_put(bio);
return ok;

View File

@ -835,8 +835,7 @@ enum {
NO_BARRIER_SUPP, /* underlying block device doesn't implement barriers */
CONSIDER_RESYNC,
MD_NO_BARRIER, /* meta data device does not support barriers,
so don't even try */
MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */
SUSPEND_IO, /* suspend application io */
BITMAP_IO, /* suspend application io;
once no more io in flight, start bitmap io */
@ -2404,13 +2403,13 @@ static inline void drbd_md_flush(struct drbd_conf *mdev)
{
int r;
if (test_bit(MD_NO_BARRIER, &mdev->flags))
if (test_bit(MD_NO_FUA, &mdev->flags))
return;
r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL,
BLKDEV_IFL_WAIT);
if (r) {
set_bit(MD_NO_BARRIER, &mdev->flags);
set_bit(MD_NO_FUA, &mdev->flags);
dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r);
}
}

View File

@ -1103,9 +1103,9 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
/* Reset the "barriers don't work" bits here, then force meta data to
* be written, to ensure we determine if barriers are supported. */
if (nbc->dc.no_md_flush)
set_bit(MD_NO_BARRIER, &mdev->flags);
set_bit(MD_NO_FUA, &mdev->flags);
else
clear_bit(MD_NO_BARRIER, &mdev->flags);
clear_bit(MD_NO_FUA, &mdev->flags);
/* Point of no return reached.
* Devices and memory are no longer released by error cleanup below.