target: make iblock_emulate_sync_cache asynchronous

Do not block the submitting thread when handling a SYNCHRONIZE CACHE command,
but implement it asynchronously by sending the FLUSH command ourself and
calling transport_complete_sync_cache from the completion handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Christoph Hellwig 2011-10-14 07:29:58 -04:00 committed by Nicholas Bellinger
parent 6b20fa9aaf
commit df5fa691ce

View File

@ -313,37 +313,42 @@ static unsigned long long iblock_emulate_read_cap_with_block_size(
return blocks_long;
}
static void iblock_end_io_flush(struct bio *bio, int err)
{
struct se_cmd *cmd = bio->bi_private;
if (err)
pr_err("IBLOCK: cache flush failed: %d\n", err);
if (cmd)
transport_complete_sync_cache(cmd, err == 0);
bio_put(bio);
}
/*
* Emulate SYCHRONIZE_CACHE_*
* Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
* always flush the whole cache.
*/
static void iblock_emulate_sync_cache(struct se_task *task)
{
struct se_cmd *cmd = task->task_se_cmd;
struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
int immed = (cmd->t_task_cdb[1] & 0x2);
sector_t error_sector;
int ret;
struct bio *bio;
/*
* If the Immediate bit is set, queue up the GOOD response
* for this SYNCHRONIZE_CACHE op
* for this SYNCHRONIZE_CACHE op.
*/
if (immed)
transport_complete_sync_cache(cmd, 1);
/*
* blkdev_issue_flush() does not support a specifying a range, so
* we have to flush the entire cache.
*/
ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
if (ret != 0) {
pr_err("IBLOCK: block_issue_flush() failed: %d "
" error_sector: %llu\n", ret,
(unsigned long long)error_sector);
}
bio = bio_alloc(GFP_KERNEL, 0);
bio->bi_end_io = iblock_end_io_flush;
bio->bi_bdev = ib_dev->ibd_bd;
if (!immed)
transport_complete_sync_cache(cmd, ret == 0);
bio->bi_private = cmd;
submit_bio(WRITE_FLUSH, bio);
}
/*