block: use strncmp() instead of strcmp() for comparing device name

Commit Message

Chengguang Xu Jan. 31, 2019, 9:25 a.m. UTC

We use strlcpy() to copy device name in register_blkdev(),
so if the device name is longer enough(accurately longer
than 15 bytes), the copied name is truncated to 15 bytes.
In this case, it's better to use strncmp() to compare device
name instead of strcmp() in unregister_blkdev(), so that
we can recognize the device name correctly.

Signed-off-by: Chengguang Xu <[e-mail]>
---
 block/genhd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/block/genhd.c b/block/genhd.c
index 1dd8fd6613b8..efc532ae9de9 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -424,7 +424,7 @@  void unregister_blkdev(unsigned int major, const char *name)
 	for (n = &major_names[index]; *n; n = &(*n)->next)
 		if ((*n)->major == major)
 			break;
-	if (!*n || strcmp((*n)->name, name)) {
+	if (!*n || strncmp((*n)->name, name, strlen((*n)->name))) {
 		WARN_ON(1);
 	} else {
 		p = *n;