tcmu: Fix flushing cmd entry dcache page

When feeding the tcmu's cmd ring, we need to flush the dcache page
for the cmd entry to make sure these kernel stores are visible to
user space mappings of that page.

For the none PAD cmd entry, this will be flushed at the end of the
tcmu_queue_cmd_ring().

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 1e69b1b32558d14cd6bdc8b39b80c88786dd9c3f..a8ff6b5fdec8f425ed79a0c924d271321fcf593f 100644 (file)
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -825,21 +825,21 @@ tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
                size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
 
                entry = (void *) mb + CMDR_OFF + cmd_head;
-               tcmu_flush_dcache_range(entry, sizeof(*entry));
                tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
                tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
                entry->hdr.cmd_id = 0; /* not used for PAD */
                entry->hdr.kflags = 0;
                entry->hdr.uflags = 0;
+               tcmu_flush_dcache_range(entry, sizeof(*entry));
 
                UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
+               tcmu_flush_dcache_range(mb, sizeof(*mb));
 
                cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
                WARN_ON(cmd_head != 0);
        }
 
        entry = (void *) mb + CMDR_OFF + cmd_head;
-       tcmu_flush_dcache_range(entry, sizeof(*entry));
        tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
        entry->hdr.cmd_id = tcmu_cmd->cmd_id;
        entry->hdr.kflags = 0;