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[PATCH-v4.12.y,1/2] tcmu: Fix flushing cmd entry dcache page

Message ID 1502075487-19236-2-git-send-email-nab@linux-iscsi.org (mailing list archive)
State New, archived
Headers show

Commit Message

Nicholas A. Bellinger Aug. 7, 2017, 3:11 a.m. UTC 
From: Xiubo Li <lixiubo@cmss.chinamobile.com>

commit 9d62bc0e6d79b11e3298e831358155930fb8f5e3 upstream.

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>
---
 drivers/target/target_core_user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index beb5f09..c8b63b8 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -699,21 +699,21 @@  static inline size_t tcmu_cmd_get_cmd_size(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;