Commit 75563adb authored by ChenXiaoSong's avatar ChenXiaoSong Committed by Steve French
Browse files

smb/client: use bsearch() to find target in smb2_error_map_table 



The smb2_error_map_table array currently has 1740 elements. When searching
for the last element, the original loop-based search method requires 1740
comparisons, while binary search algorithm requires only 10 comparisons.

Suggested-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/linux-cifs/20260106071507.1420900-5-chenxiaosong.chenxiaosong@linux.dev/


Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 453382f1

fs/smb/client/smb2maperror.c

+34 −12
Original line number Diff line number Diff line
@@ -30,13 +30,36 @@ static const struct status_to_posix_error smb2_error_map_table[] = { 
#include "smb2_mapping_table.c"

};



static __always_inline int cmp_smb2_status(const void *_key, const void *_pivot)

{

	__u32 key = *(__u32 *)_key;

	const struct status_to_posix_error *pivot = _pivot;



	if (key < pivot->smb2_status)

		return -1;

	if (key > pivot->smb2_status)

		return 1;

	return 0;

}



static const struct status_to_posix_error *smb2_get_err_map(__u32 smb2_status)

{

	const struct status_to_posix_error *err_map;



	err_map = __inline_bsearch(&smb2_status, smb2_error_map_table,

				   ARRAY_SIZE(smb2_error_map_table),

				   sizeof(struct status_to_posix_error),

				   cmp_smb2_status);

	return err_map;

}



int

map_smb2_to_linux_error(char *buf, bool log_err)

{

	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;

	unsigned int i;

	int rc = -EIO;

	__le32 smb2err = shdr->Status;

	const struct status_to_posix_error *err_map;



	if (smb2err == 0) {

		trace_smb3_cmd_done(le32_to_cpu(shdr->Id.SyncId.TreeId),
@@ -50,21 +73,20 @@ map_smb2_to_linux_error(char *buf, bool log_err) 
		   (smb2err != STATUS_END_OF_FILE)) ||

		  (cifsFYI & CIFS_RC);



	for (i = 0; i < sizeof(smb2_error_map_table) /

			sizeof(struct status_to_posix_error); i++) {

		if (smb2_error_map_table[i].smb2_status == smb2err) {

	err_map = smb2_get_err_map(le32_to_cpu(smb2err));

	if (!err_map)

		goto out;



	rc = err_map->posix_error;

	if (log_err)

				pr_notice("Status code returned 0x%08x %s\n", smb2err,

					  smb2_error_map_table[i].status_string);

			rc = smb2_error_map_table[i].posix_error;

			break;

		}

	}

		pr_notice("Status code returned 0x%08x %s\n",

			  err_map->smb2_status, err_map->status_string);



out:

	/* on error mapping not found  - return EIO */



	cifs_dbg(FYI, "Mapping SMB2 status code 0x%08x to POSIX err %d\n",

		 __le32_to_cpu(smb2err), rc);

		 le32_to_cpu(smb2err), rc);



	trace_smb3_cmd_err(le32_to_cpu(shdr->Id.SyncId.TreeId),

			   le64_to_cpu(shdr->SessionId),