From 8e69212253d320d4768071086b1111e6ab91d9bd Mon Sep 17 00:00:00 2001

From: Kari Argillander <kari.argillander@gmail.com>

Date: Thu, 2 Sep 2021 18:40:50 +0300

Subject: [Backport 8e69212253d3] src: Always use binary search with entry

 search

We do not have any reason to keep old linear search in. Before this was

used for error path or if table was so big that it cannot be allocated.

Current binary search implementation won't need error path. Remove old

references to linear entry search.

Signed-off-by: Kari Argillander <kari.argillander@gmail.com>

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

---

 src/index.c | 50 ++++++------------------------------------------

 src/ntfs.h  |  3 ---

 2 files changed, 6 insertions(+), 47 deletions(-)

diff --git a/src/index.c b/src/index.c

index 3ad1ee608e531ea7c7793e691fe706ee0a6c33a4..4f71a91f07d9fc56efe6a80ebf52995e2e9a65de 100644

--- a/src/index.c

+++ b/src/index.c

@@ -671,22 +671,16 @@ static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,

 				  const struct INDEX_HDR *hdr, const void *key,

 				  size_t key_len, const void *ctx, int *diff)

 {

-	struct NTFS_DE *e;

+	struct NTFS_DE *e, *found = NULL;

 	NTFS_CMP_FUNC cmp = indx->cmp;

+	int min_idx = 0, mid_idx, max_idx = 0;

+	int diff2;

+	int table_size = 8;

 	u32 e_size, e_key_len;

 	u32 end = le32_to_cpu(hdr->used);

 	u32 off = le32_to_cpu(hdr->de_off);

-

-#ifdef NTFS3_INDEX_BINARY_SEARCH

-	struct NTFS_DE *found = NULL;

-	int min_idx = 0, mid_idx, max_idx = 0;

-	int table_size = 8;

-	int diff2;

 	u16 offs[128];

-	if (end > 0x10000)

-		goto next;

-

 fill_table:

 	if (off + sizeof(struct NTFS_DE) > end)

 		return NULL;

@@ -720,7 +714,8 @@ static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,

 				return NULL;

 			max_idx = 0;

-			table_size = min(table_size * 2, 128);

+			table_size = min(table_size * 2,

+					 (int)ARRAY_SIZE(offs));

 			goto fill_table;

 		}

 	} else if (diff2 < 0) {

@@ -744,39 +739,6 @@ static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,

 	e = Add2Ptr(hdr, offs[mid_idx]);

 	goto binary_search;

-#endif

-

-next:

-	/*

-	 * Entries index are sorted.

-	 * Enumerate all entries until we find entry

-	 * that is <= to the search value.

-	 */

-	if (off + sizeof(struct NTFS_DE) > end)

-		return NULL;

-

-	e = Add2Ptr(hdr, off);

-	e_size = le16_to_cpu(e->size);

-

-	if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)

-		return NULL;

-

-	off += e_size;

-

-	e_key_len = le16_to_cpu(e->key_size);

-

-	*diff = (*cmp)(key, key_len, e + 1, e_key_len, ctx);

-	if (!*diff)

-		return e;

-

-	if (*diff <= 0)

-		return e;

-

-	if (de_is_last(e)) {

-		*diff = 1;

-		return e;

-	}

-	goto next;

 }

 /*

diff --git a/src/ntfs.h b/src/ntfs.h

index 695b684bce20dd4f274884ba9a1022555b47823a..303a162c31587475adb8c3190b16fa451e9616a7 100644

--- a/src/ntfs.h

+++ b/src/ntfs.h

@@ -21,9 +21,6 @@

 /* TODO: Check 4K MFT record and 512 bytes cluster. */

-/* Activate this define to use binary search in indexes. */

-#define NTFS3_INDEX_BINARY_SEARCH

-

 /* Check each run for marked clusters. */

 #define NTFS3_CHECK_FREE_CLST

-- 

2.31.1