These changes are a raw update to a vanilla kernel 4.1.10, with the

[kvmfornfv.git] / kernel / block / blk-mq-sysfs.c

diff --git a/kernel/block/blk-mq-sysfs.c b/kernel/block/blk-mq-sysfs.c
index b79685e..279c5d6 100644 (file)
--- a/kernel/block/blk-mq-sysfs.c
+++ b/kernel/block/blk-mq-sysfs.c
@@ -141,15 +141,26 @@ static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page)
 
 static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg)
 {
-       char *start_page = page;
        struct request *rq;
+       int len = snprintf(page, PAGE_SIZE - 1, "%s:\n", msg);
+
+       list_for_each_entry(rq, list, queuelist) {
+               const int rq_len = 2 * sizeof(rq) + 2;
+
+               /* if the output will be truncated */
+               if (PAGE_SIZE - 1 < len + rq_len) {
+                       /* backspacing if it can't hold '\t...\n' */
+                       if (PAGE_SIZE - 1 < len + 5)
+                               len -= rq_len;
+                       len += snprintf(page + len, PAGE_SIZE - 1 - len,
+                                       "\t...\n");
+                       break;
+               }
+               len += snprintf(page + len, PAGE_SIZE - 1 - len,
+                               "\t%p\n", rq);
+       }
 
-       page += sprintf(page, "%s:\n", msg);
-
-       list_for_each_entry(rq, list, queuelist)
-               page += sprintf(page, "\t%p\n", rq);
-
-       return page - start_page;
+       return len;
 }
 
 static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page)