diff options
| author | Christoph Hellwig <hch@infradead.org> | 2009-09-30 13:52:12 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-10-01 21:19:30 +0200 |
| commit | c15227de132f1295f3db6b7df9079956b1020fd8 (patch) | |
| tree | ad06f119f283cf8a6313681055e8132ba2851ddb /drivers/staging/dst | |
| parent | 3bd0f0c763e497c8674b28e3df2732f48683dabd (diff) | |
block: use normal I/O path for discard requests
prepare_discard_fn() was being called in a place where memory allocation
was effectively impossible. This makes it inappropriate for all but
the most trivial translations of Linux's DISCARD operation to the block
command set. Additionally adding a payload there makes the ownership
of the bio backing unclear as it's now allocated by the device driver
and not the submitter as usual.
It is replaced with QUEUE_FLAG_DISCARD which is used to indicate whether
the queue supports discard operations or not. blkdev_issue_discard now
allocates a one-page, sector-length payload which is the right thing
for the common ATA and SCSI implementations.
The mtd implementation of prepare_discard_fn() is replaced with simply
checking for the request being a discard.
Largely based on a previous patch from Matthew Wilcox <matthew@wil.cx>
which did the prepare_discard_fn but not the different payload allocation
yet.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/staging/dst')
| -rw-r--r-- | drivers/staging/dst/dcore.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/dst/dcore.c b/drivers/staging/dst/dcore.c index ac8577358ba..5e8db067758 100644 --- a/drivers/staging/dst/dcore.c +++ b/drivers/staging/dst/dcore.c @@ -102,7 +102,7 @@ static int dst_request(struct request_queue *q, struct bio *bio) struct dst_node *n = q->queuedata; int err = -EIO; - if (bio_empty_barrier(bio) && !q->prepare_discard_fn) { + if (bio_empty_barrier(bio) && !blk_queue_discard(q)) { /* * This is a dirty^Wnice hack, but if we complete this * operation with -EOPNOTSUPP like intended, XFS |