[PATCH 12/30] smb/client: use bsearch() to find target in ntstatus_to_dos_map array

chenxiaosong.chenxiaosong@linux.dev posted 30 patches 1 week, 4 days ago
[PATCH 12/30] smb/client: use bsearch() to find target in ntstatus_to_dos_map array
Posted by chenxiaosong.chenxiaosong@linux.dev 1 week, 4 days ago
From: ChenXiaoSong <chenxiaosong@kylinos.cn>

The array currently has 525 elements. When searching for the last element,
the original loop-based search method requires 525 comparisons, while
binary search algorithm requires only 9 comparisons.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 fs/smb/client/netmisc.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/fs/smb/client/netmisc.c b/fs/smb/client/netmisc.c
index 8a84f826d486..55100c2c14cf 100644
--- a/fs/smb/client/netmisc.c
+++ b/fs/smb/client/netmisc.c
@@ -803,6 +803,9 @@ static unsigned int ntstatus_to_dos_num = sizeof(ntstatus_to_dos_map) /
 /* cmp_ntstatus_to_dos */
 DEFINE_CMP_FUNC(ntstatus_to_dos, ntstatus);
 
+/* search_in_ntstatus_to_dos_map */
+DEFINE_SEARCH_FUNC(ntstatus_to_dos, ntstatus, ntstatus_to_dos_map, ntstatus_to_dos_num);
+
 /*****************************************************************************
  Print an error message from the status code
  *****************************************************************************/
@@ -826,19 +829,21 @@ cifs_print_status(__u32 status_code)
 static void
 ntstatus_to_dos(__u32 ntstatus, __u8 *eclass, __u16 *ecode)
 {
-	int i;
+	struct ntstatus_to_dos *err_map;
+
 	if (ntstatus == 0) {
 		*eclass = 0;
 		*ecode = 0;
 		return;
 	}
-	for (i = 0; ntstatus_to_dos_map[i].ntstatus; i++) {
-		if (ntstatus == ntstatus_to_dos_map[i].ntstatus) {
-			*eclass = ntstatus_to_dos_map[i].dos_class;
-			*ecode = ntstatus_to_dos_map[i].dos_code;
-			return;
-		}
+
+	err_map = search_in_ntstatus_to_dos_map(ntstatus);
+	if (err_map) {
+		*eclass = err_map->dos_class;
+		*ecode = err_map->dos_code;
+		return;
 	}
+
 	*eclass = ERRHRD;
 	*ecode = ERRgeneral;
 }
-- 
2.43.0