scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in new_tape_buffer

new_tape_buffer() is never called in atomic context. new_tape_buffer()
is only called by st_probe(), which is only set as ".probe" in struct
scsi_driver.

Despite never getting called from atomic context, new_tape_buffer()
calls kzalloc() with GFP_ATOMIC, which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, which
can sleep and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 4c7d39b825a3ad853afda867757d3724e91cdc5f..e64489a4a9a610e76109e4b4fa8fa6a3f6c86a51 100644 (file)
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -3878,7 +3878,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
 {
        struct st_buffer *tb;
 
-       tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
+       tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
        if (!tb) {
                printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
                return NULL;
@@ -3889,7 +3889,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
        tb->buffer_size = 0;
 
        tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
-                                    GFP_ATOMIC);
+                                    GFP_KERNEL);
        if (!tb->reserved_pages) {
                kfree(tb);
                return NULL;