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From:   "Rodrigo R. Galvao" <rosattig@linux.vnet.ibm.com>
Cc:     hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org,
        linux-kernel@vger.kernel.org, rosattig@linux.vnet.ibm.com,
        rodrigorosattig@gmail.com
Subject: [PATCH v3] nvmet: fix nvmet_execute_write_zeroes function
Date:   Mon,  2 Apr 2018 13:31:39 -0300
Message-Id: <1522686699-26894-1-git-send-email-rosattig@linux.vnet.ibm.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When trying to issue write_zeroes command against TARGET with a 4K block
size, it ends up hitting the following condition at __blkdev_issue_zeroout:

     if ((sector | nr_sects) & bs_mask)
                return -EINVAL;

Causing the command to always fail.
Considering we need to add 1 to get the correct block count, that addition
needs to be performed in the native format, so we moved the +1 right after
le16_to_cpu prior to converting to 512b.

Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com>
---
 drivers/nvme/target/io-cmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/io-cmd.c b/drivers/nvme/target/io-cmd.c
index 28bbdff..cd23441 100644
--- a/drivers/nvme/target/io-cmd.c
+++ b/drivers/nvme/target/io-cmd.c
@@ -173,8 +173,8 @@ static void nvmet_execute_write_zeroes(struct nvmet_req *req)
 
 	sector = le64_to_cpu(write_zeroes->slba) <<
 		(req->ns->blksize_shift - 9);
-	nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length)) <<
-		(req->ns->blksize_shift - 9)) + 1;
+	nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
+		(req->ns->blksize_shift - 9));
 
 	if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 				GFP_KERNEL, &bio, 0))
-- 
2.7.4