nvmet: add support for the Write Zeroes command
Add support for handling write zeroes command on target.
Call into __blkdev_issue_zeroout, which the block layer expands into the
best suitable variant of zeroing the LBAs. Allow write zeroes operation
to deallocate the LBAs when calling __blkdev_issue_zeroout.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 7ab9c93..383ea10 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -237,7 +237,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
id->nn = cpu_to_le32(ctrl->subsys->max_nsid);
- id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM);
+ id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
+ NVME_CTRL_ONCS_WRITE_ZEROES);
/* XXX: don't report vwc if the underlying device is write through */
id->vwc = NVME_CTRL_VWC_PRESENT;