shithub: lwext4

Download patch

ref: 94d428f1fb88c5c45eba3fd586fa73e5d346b9e0
parent: 90ed580cfaf169c57bc1a3e2117a6f72184b36ec
author: ngkaho1234 <[email protected]>
date: Thu Oct 1 15:10:57 EDT 2015

FIX: block bitmap is not correctly initialized.

--- a/lwext4/ext4_balloc.c
+++ b/lwext4/ext4_balloc.c
@@ -52,8 +52,8 @@
  * @param baddr Absolute address of block.
  * @return Block group index
  */
-static uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
-					      uint32_t baddr)
+uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
+				       uint32_t baddr)
 {
 	if (ext4_get32(s, first_data_block))
 		baddr--;
@@ -61,37 +61,20 @@
 	return baddr / ext4_get32(s, blocks_per_group);
 }
 
-uint32_t
-ext4_balloc_get_first_data_block_in_group(struct ext4_sblock *s,
-					  struct ext4_block_group_ref *bg_ref)
+/**@brief Compute the starting block address of a block group
+ * @param sb   superblock pointer.
+ * @param bgid block group index
+ * @return Block address
+ */
+uint32_t ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
+				       uint32_t bgid)
 {
-	uint32_t block_group_count = ext4_block_group_cnt(s);
-	uint32_t inode_table_first_block =
-	    ext4_bg_get_inode_table_first_block(bg_ref->block_group, s);
-	uint32_t block_size = ext4_sb_get_block_size(s);
+	uint32_t baddr = 0;
+	if (ext4_get32(s, first_data_block))
+		baddr++;
 
-	uint16_t inode_size = ext4_get16(s, inode_size);
-	uint32_t inodes_per_group = ext4_get32(s, inodes_per_group);
-
-	uint32_t inode_table_bytes;
-
-	if (bg_ref->index < block_group_count - 1) {
-		inode_table_bytes = inodes_per_group * inode_size;
-	} else {
-		/* Last block group could be smaller */
-		uint32_t inodes_count_total = ext4_get32(s, inodes_count);
-		inode_table_bytes =
-		    (inodes_count_total -
-		     ((block_group_count - 1) * inodes_per_group)) *
-		    inode_size;
-	}
-
-	uint32_t inode_table_blocks = inode_table_bytes / block_size;
-
-	if (inode_table_bytes % block_size)
-		inode_table_blocks++;
-
-	return inode_table_first_block + inode_table_blocks;
+	baddr += bgid * ext4_get32(s, blocks_per_group);
+	return baddr;
 }
 
 int ext4_balloc_free_block(struct ext4_inode_ref *inode_ref, uint32_t baddr)
@@ -369,8 +352,7 @@
 	}
 
 	/* Compute indexes */
-	uint32_t first_in_group =
-	    ext4_balloc_get_first_data_block_in_group(sb, &bg_ref);
+	uint32_t first_in_group = ext4_balloc_get_block_of_bgid(sb, bg_ref.index);
 
 	uint32_t first_in_group_index =
 	    ext4_fs_baddr2_index_in_group(sb, first_in_group);
@@ -488,8 +470,7 @@
 		}
 
 		/* Compute indexes */
-		first_in_group =
-		    ext4_balloc_get_first_data_block_in_group(sb, &bg_ref);
+		first_in_group = ext4_balloc_get_block_of_bgid(sb, bgid);
 		index_in_group =
 		    ext4_fs_baddr2_index_in_group(sb, first_in_group);
 		blocks_in_group = ext4_blocks_in_group_cnt(sb, bgid);
--- a/lwext4/ext4_balloc.h
+++ b/lwext4/ext4_balloc.h
@@ -48,13 +48,21 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-/**@brief   Get first datablock in block group
- * @param   s superblock descriptor
- * @param   bg_ref block group reference
- * @return  block id of the first datablock in block group*/
-uint32_t
-ext4_balloc_get_first_data_block_in_group(struct ext4_sblock *s,
-					  struct ext4_block_group_ref *bg_ref);
+/**@brief Compute number of block group from block address.
+ * @param sb superblock pointer.
+ * @param baddr Absolute address of block.
+ * @return Block group index
+ */
+uint32_t ext4_balloc_get_bgid_of_block(struct ext4_sblock *s,
+				       uint32_t baddr);
+
+/**@brief Compute the starting block address of a block group
+ * @param sb   superblock pointer.
+ * @param bgid block group index
+ * @return Block address
+ */
+uint32_t ext4_balloc_get_block_of_bgid(struct ext4_sblock *s,
+				       uint32_t bgid);
 
 /**@brief   Free block from inode.
  * @param   inode_ref inode reference
--- a/lwext4/ext4_config.h
+++ b/lwext4/ext4_config.h
@@ -114,7 +114,7 @@
 
 /**@brief   Include assert codes from ext4_debug or standard library.*/
 #ifndef CONFIG_HAVE_OWN_ASSERT
-#define CONFIG_HAVE_OWN_ASSERT 1
+#define CONFIG_HAVE_OWN_ASSERT 0
 #endif
 
 /**@brief   Statistics of block device*/
--- a/lwext4/ext4_fs.c
+++ b/lwext4/ext4_fs.c
@@ -271,6 +271,40 @@
 	return EOK;
 }
 
+/**@brief Determine whether the block is inside the group.
+ * @param baddr   block address
+ * @param bgid    block group id
+ * @return Error code
+ */
+static int ext4_block_in_group(struct ext4_sblock *s,
+			       uint32_t baddr,
+			       uint32_t bgid)
+{
+	uint32_t actual_bgid;
+	actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
+	if (actual_bgid == bgid)
+		return 1;
+	return 0;
+}
+
+/**@brief   To avoid calling the atomic setbit hundreds or thousands of times, we only
+ *          need to use it within a single byte (to ensure we get endianness right).
+ *          We can use memset for the rest of the bitmap as there are no other users.
+ */
+static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
+{
+	int i;
+
+	if (start_bit >= end_bit)
+		return;
+
+	for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
+		ext4_bmap_bit_set(bitmap, i);
+
+	if (i < end_bit)
+		memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
+}
+
 /**@brief Initialize block bitmap in block group.
  * @param bg_ref Reference to block group
  * @return Error code
@@ -277,10 +311,31 @@
  */
 static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
 {
-	uint32_t i;
+	uint32_t i, bit, bit_max;
+	uint32_t group_blocks;
+	uint16_t inode_size = ext4_get16(&bg_ref->fs->sb, inode_size);
+	uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
+	uint32_t inodes_per_group = ext4_get32(&bg_ref->fs->sb, inodes_per_group);
 	uint32_t bitmap_block_addr =
 	    ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
+	uint32_t bitmap_inode_addr =
+	    ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
+	uint32_t inode_table_addr =
+	    ext4_bg_get_inode_table_first_block(bg_ref->block_group,
+						&bg_ref->fs->sb);
+	uint32_t first_group_addr =
+	    ext4_balloc_get_block_of_bgid(&bg_ref->fs->sb, bg_ref->index);
 
+	uint32_t dsc_per_block =
+	    ext4_sb_get_block_size(&bg_ref->fs->sb) /
+	    ext4_sb_get_desc_size(&bg_ref->fs->sb);
+
+	bool flex_bg =
+		ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
+						 EXT4_FEATURE_INCOMPAT_FLEX_BG);
+
+	uint32_t inode_table_bcnt = inodes_per_group * inode_size / block_size;
+
 	struct ext4_block block_bitmap;
 	int rc =
 	    ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
@@ -287,22 +342,67 @@
 	if (rc != EOK)
 		return rc;
 
-	memset(block_bitmap.data, 0, ext4_sb_get_block_size(&bg_ref->fs->sb));
+	memset(block_bitmap.data, 0, block_size);
 
-	/* Determine first block and first data block in group */
-	uint32_t first_idx = 0;
+	bit_max = ext4_sb_is_super_in_bg(&bg_ref->fs->sb, bg_ref->index);
+	if (!ext4_sb_has_feature_incompatible(&bg_ref->fs->sb,
+					      EXT4_FEATURE_INCOMPAT_META_BG) ||
+			bg_ref->index < ext4_sb_first_meta_bg(&bg_ref->fs->sb) *
+			dsc_per_block) {
+		if (bit_max) {
+			bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
+						   bg_ref->index);
+			bit_max +=
+				ext4_get16(&bg_ref->fs->sb,
+					   s_reserved_gdt_blocks);
+		}
+	} else { /* For META_BG_BLOCK_GROUPS */
+		bit_max += ext4_bg_num_gdb(&bg_ref->fs->sb,
+					   bg_ref->index);
+	}
+        for (bit = 0; bit < bit_max; bit++)
+            ext4_bmap_bit_set(block_bitmap.data, bit);
 
-	uint32_t first_data =
-	    ext4_balloc_get_first_data_block_in_group(&bg_ref->fs->sb, bg_ref);
-	uint32_t first_data_idx =
-	    ext4_fs_baddr2_index_in_group(&bg_ref->fs->sb, first_data);
+	if (bg_ref->index == ext4_block_group_cnt(&bg_ref->fs->sb) - 1) {
+		/*
+		 * Even though mke2fs always initialize first and last group
+		 * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
+		 * to make sure we calculate the right free blocks
+		 */
+		group_blocks = (ext4_sb_get_blocks_cnt(&bg_ref->fs->sb) -
+				ext4_get32(&bg_ref->fs->sb, first_data_block) -
+				(ext4_get32(&bg_ref->fs->sb, blocks_per_group) *
+				 (ext4_block_group_cnt(&bg_ref->fs->sb) - 1)));
+	} else {
+		group_blocks = ext4_get32(&bg_ref->fs->sb, blocks_per_group);
+	}
+	if (!flex_bg ||
+	    ext4_block_in_group(&bg_ref->fs->sb,
+				bitmap_block_addr, bg_ref->index))
+		ext4_bmap_bit_set(block_bitmap.data,
+				  bitmap_block_addr - first_group_addr);
 
-	/*Set bits from to first block to first data block - 1 to one
-	 * (allocated)*/
-	/*TODO: Optimize it*/
-	for (i = first_idx; i < first_data_idx; ++i)
-		ext4_bmap_bit_set(block_bitmap.data, i);
+	if (!flex_bg ||
+	    ext4_block_in_group(&bg_ref->fs->sb,
+				bitmap_inode_addr, bg_ref->index))
+		ext4_bmap_bit_set(block_bitmap.data,
+				  bitmap_inode_addr - first_group_addr);
 
+        for (i = inode_table_addr;
+		i < inode_table_addr + inode_table_bcnt; i++) {
+		if (!flex_bg ||
+		    ext4_block_in_group(&bg_ref->fs->sb,
+					i,
+					bg_ref->index))
+			ext4_bmap_bit_set(block_bitmap.data,
+					i - first_group_addr);
+	}
+        /*
+         * Also if the number of blocks within the group is
+         * less than the blocksize * 8 ( which is the size
+         * of bitmap ), set rest of the block bitmap to 1
+         */
+        ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
 	block_bitmap.dirty = true;
 
 	/* Save bitmap */
--- a/lwext4/ext4_fs.h
+++ b/lwext4/ext4_fs.h
@@ -56,7 +56,6 @@
 static inline uint32_t ext4_fs_baddr2_index_in_group(struct ext4_sblock *s,
 						     uint32_t baddr)
 {
-	ext4_assert(baddr);
 	if (ext4_get32(s, first_data_block))
 		baddr--;