From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Mon, 23 Sep 2013 18:42:28 +0000 (-0700)
Subject: vhost/scsi: Use GFP_ATOMIC with percpu_ida_alloc for obtaining tag
X-Git-Tag: v5.15~19106^2~19
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4a47d3a1ff10e564bf04f27ac14552df64f60cdf;p=platform%2Fkernel%2Flinux-starfive.git

vhost/scsi: Use GFP_ATOMIC with percpu_ida_alloc for obtaining tag

Fix GFP_KERNEL -> GFP_ATOMIC usage of percpu_ida_alloc() within
vhost_scsi_get_tag(), as this code is expected to be called directly
from interrupt context.

v2 changes:

  - Handle possible tag < 0 failure with GFP_ATOMIC

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Asias He <asias@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 592b316..ce5221f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -728,7 +728,12 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq,
 	}
 	se_sess = tv_nexus->tvn_se_sess;
 
-	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_KERNEL);
+	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC);
+	if (tag < 0) {
+		pr_err("Unable to obtain tag for tcm_vhost_cmd\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
 	cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[tag];
 	sg = cmd->tvc_sgl;
 	pages = cmd->tvc_upages;