From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Date: Wed, 25 Oct 2017 16:47:25 +0000 Subject: [PATCH 15/20] tcmu: fix free block calculation Message-Id: <1508950050-10120-16-git-send-email-mchristi@redhat.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: target-devel@vger.kernel.org The blocks_left calculation does not account for free blocks between 0 and thresh, so we could be queueing/waiting when there are enough blocks free. This has us add in the blocks between 0 and thresh as well as at the end from thresh to DATA_BLOCK_BITS. Signed-off-by: Mike Christie --- drivers/target/target_core_user.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 45cf37f..5eb919a 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -675,7 +675,7 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh) { - return DATA_BLOCK_SIZE * (thresh - bitmap_weight(bitmap, thresh)); + return thresh - bitmap_weight(bitmap, thresh); } /* @@ -715,8 +715,9 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, /* try to check and get the data blocks as needed */ space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh); - if (space < data_needed) { - unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh; + if ((space * DATA_BLOCK_SIZE) < data_needed) { + unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh + + space; unsigned long grow; if (blocks_left < blocks_needed) { -- 2.7.2