[PATCH] bitops: ntfs: remove generic_ffs()

Now the only user who are using generic_ffs() is ntfs filesystem.  This patch
isolates generic_ffs() as ntfs_ffs() for ntfs.

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ntfs/logfile.c

@@ -515,10 +515,10 @@ BOOL ntfs_check_logfile(struct inode *log_vi, RESTART_PAGE_HEADER **rp)
 		log_page_size = PAGE_CACHE_SIZE;
 	log_page_mask = log_page_size - 1;
 	/*
-	 * Use generic_ffs() instead of ffs() to enable the compiler to
+	 * Use ntfs_ffs() instead of ffs() to enable the compiler to
 	 * optimize log_page_size and log_page_bits into constants.
 	 */
-	log_page_bits = generic_ffs(log_page_size) - 1;
+	log_page_bits = ntfs_ffs(log_page_size) - 1;
 	size &= ~(s64)(log_page_size - 1);
 	/*
 	 * Ensure the log file is big enough to store at least the two restart

fs/ntfs/mft.c

@@ -2670,7 +2670,7 @@ mft_rec_already_initialized:
 			ni->name_len = 4;
 
 			ni->itype.index.block_size = 4096;
-			ni->itype.index.block_size_bits = generic_ffs(4096) - 1;
+			ni->itype.index.block_size_bits = ntfs_ffs(4096) - 1;
 			ni->itype.index.collation_rule = COLLATION_FILE_NAME;
 			if (vol->cluster_size <= ni->itype.index.block_size) {
 				ni->itype.index.vcn_size = vol->cluster_size;

fs/ntfs/ntfs.h

@@ -132,4 +132,33 @@ extern int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
 /* From fs/ntfs/upcase.c */
 extern ntfschar *generate_default_upcase(void);
 
+static inline int ntfs_ffs(int x)
+{
+	int r = 1;
+
+	if (!x)
+		return 0;
+	if (!(x & 0xffff)) {
+		x >>= 16;
+		r += 16;
+	}
+	if (!(x & 0xff)) {
+		x >>= 8;
+		r += 8;
+	}
+	if (!(x & 0xf)) {
+		x >>= 4;
+		r += 4;
+	}
+	if (!(x & 3)) {
+		x >>= 2;
+		r += 2;
+	}
+	if (!(x & 1)) {
+		x >>= 1;
+		r += 1;
+	}
+	return r;
+}
+
 #endif /* _LINUX_NTFS_H */