[PATCH V3 (resend) 2/7] CIFS: SMBD: Do not call ib_dereg_mr on invalidated memory registration

From: Long Li
Date: Thu Sep 20 2018 - 17:20:02 EST


From: Long Li <longli@xxxxxxxxxxxxx>

It is not necessary to deregister a memory registration after it has been
successfully invalidated.

Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
fs/cifs/smbdirect.c | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 5fdb9a5..5e28236 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2295,8 +2295,12 @@ static void smbd_mr_recovery_work(struct work_struct *work)
int rc;

list_for_each_entry(smbdirect_mr, &info->mr_list, list) {
- if (smbdirect_mr->state == MR_INVALIDATED ||
- smbdirect_mr->state == MR_ERROR) {
+ if (smbdirect_mr->state == MR_INVALIDATED)
+ ib_dma_unmap_sg(
+ info->id->device, smbdirect_mr->sgl,
+ smbdirect_mr->sgl_count,
+ smbdirect_mr->dir);
+ else if (smbdirect_mr->state == MR_ERROR) {

/* recover this MR entry */
rc = ib_dereg_mr(smbdirect_mr->mr);
@@ -2320,25 +2324,21 @@ static void smbd_mr_recovery_work(struct work_struct *work)
smbd_disconnect_rdma_connection(info);
continue;
}
+ } else
+ /* This MR is being used, don't recover it */
+ continue;

- if (smbdirect_mr->state == MR_INVALIDATED)
- ib_dma_unmap_sg(
- info->id->device, smbdirect_mr->sgl,
- smbdirect_mr->sgl_count,
- smbdirect_mr->dir);
-
- smbdirect_mr->state = MR_READY;
+ smbdirect_mr->state = MR_READY;

- /* smbdirect_mr->state is updated by this function
- * and is read and updated by I/O issuing CPUs trying
- * to get a MR, the call to atomic_inc_return
- * implicates a memory barrier and guarantees this
- * value is updated before waking up any calls to
- * get_mr() from the I/O issuing CPUs
- */
- if (atomic_inc_return(&info->mr_ready_count) == 1)
- wake_up_interruptible(&info->wait_mr);
- }
+ /* smbdirect_mr->state is updated by this function
+ * and is read and updated by I/O issuing CPUs trying
+ * to get a MR, the call to atomic_inc_return
+ * implicates a memory barrier and guarantees this
+ * value is updated before waking up any calls to
+ * get_mr() from the I/O issuing CPUs
+ */
+ if (atomic_inc_return(&info->mr_ready_count) == 1)
+ wake_up_interruptible(&info->wait_mr);
}
}

--
2.7.4