Reconstruct source directory tree.

1 files changed, 156 insertions, 0 deletions

diff --git a/src/ext4_bitmap.c b/src/ext4_bitmap.c
new file mode 100644
index 0000000..1320033
--- /dev/null
+++ b/src/ext4_bitmap.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup lwext4
+ * @{
+ */
+/**
+ * @file  ext4_bitmap.c
+ * @brief Block/inode bitmap allocator.
+ */
+
+#include "ext4_config.h"
+#include "ext4_bitmap.h"
+
+#include "ext4_errno.h"
+
+void ext4_bmap_bits_free(uint8_t *bmap, uint32_t sbit, uint32_t bcnt)
+{
+	uint32_t i = sbit;
+
+	while (i & 7) {
+
+		if (!bcnt)
+			return;
+
+		ext4_bmap_bit_clr(bmap, i);
+
+		bcnt--;
+		i++;
+	}
+	sbit = i;
+	bmap += (sbit >> 3);
+
+	while (bcnt >= 32) {
+		*(uint32_t *)bmap = 0;
+		bmap += 4;
+		bcnt -= 32;
+		sbit += 32;
+	}
+
+	while (bcnt >= 16) {
+		*(uint16_t *)bmap = 0;
+		bmap += 2;
+		bcnt -= 16;
+		sbit += 16;
+	}
+
+	while (bcnt >= 8) {
+		*bmap = 0;
+		bmap += 1;
+		bcnt -= 8;
+		sbit += 8;
+	}
+
+	for (i = 0; i < bcnt; ++i) {
+		ext4_bmap_bit_clr(bmap, i);
+	}
+}
+
+int ext4_bmap_bit_find_clr(uint8_t *bmap, uint32_t sbit, uint32_t ebit,
+			   uint32_t *bit_id)
+{
+	uint32_t i;
+	uint32_t bcnt = ebit - sbit;
+
+	i = sbit;
+
+	while (i & 7) {
+
+		if (!bcnt)
+			return ENOSPC;
+
+		if (ext4_bmap_is_bit_clr(bmap, i)) {
+			*bit_id = sbit;
+			return EOK;
+		}
+
+		i++;
+		bcnt--;
+	}
+
+	sbit = i;
+	bmap += (sbit >> 3);
+
+	while (bcnt >= 32) {
+		if (*(uint32_t *)bmap != 0xFFFFFFFF)
+			goto finish_it;
+
+		bmap += 4;
+		bcnt -= 32;
+		sbit += 32;
+	}
+
+	while (bcnt >= 16) {
+		if (*(uint16_t *)bmap != 0xFFFF)
+			goto finish_it;
+
+		bmap += 2;
+		bcnt -= 16;
+		sbit += 16;
+	}
+
+finish_it:
+	while (bcnt >= 8) {
+		if (*bmap != 0xFF) {
+			for (i = 0; i < 8; ++i) {
+				if (ext4_bmap_is_bit_clr(bmap, i)) {
+					*bit_id = sbit + i;
+					return EOK;
+				}
+			}
+		}
+
+		bmap += 1;
+		bcnt -= 8;
+		sbit += 8;
+	}
+
+	for (i = 0; i < bcnt; ++i) {
+		if (ext4_bmap_is_bit_clr(bmap, i)) {
+			*bit_id = sbit + i;
+			return EOK;
+		}
+	}
+
+	return ENOSPC;
+}
+
+/**
+ * @}
+ */