ext3-16tb-overflow-fixes.patch

非常经典的一个分布式系统

 				EXT3_XATTR_REFCOUNT_MAX) {

Date: Tue, 19 Sep 2006 15:32:02 -0500
From: Eric Sandeen <[e-mail]>
Subject: [RHEL5 Patch 1/3] (resend) Fix ext3 overflows at 16T

This one is in -mm as fix-ext3-mounts-at-16t.patch and 
fix-ext3-mounts-at-16t-fix.patch  

this gets things mounting for a 16T ext3 filesystem.  (patched up 
e2fsprogs will be needed too, working on that)

jarod wilson has been helping with testing.

This patch fixes these issues in the kernel:

o sbi->s_groups_count overflows in ext3_fill_super()

	sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
			       le32_to_cpu(es->s_first_data_block) +
			       EXT3_BLOCKS_PER_GROUP(sb) - 1) /
			      EXT3_BLOCKS_PER_GROUP(sb);

  at 16T, s_blocks_count is already maxed out; adding
  EXT3_BLOCKS_PER_GROUP(sb) overflows it and groups_count comes out to 0. 
  Not really what we want, and causes a failed mount.

  Changing it this way works & avoids the overflow:

  (A + B - 1)/B changed to: ((A - 1)/B) + 1

o ext3_check_descriptors() overflows range checks

  ext3_check_descriptors() iterates over all block groups making sure
  that various bits are within the right block ranges...  on the last pass
  through, it is checking the error case

   [item] >= block + EXT3_BLOCKS_PER_GROUP(sb)

  where "block" is the first block in the last block group.  The last
  block in this group (and the last one that will fit in 32 bits) is block
  + EXT3_BLOCKS_PER_GROUP(sb)- 1.  block + EXT3_BLOCKS_PER_GROUP(sb) wraps
  back around to 0.

  so, make things clearer with "first_block" and "last_block" where those
  are first and last, inclusive, and use <, > rather than <, >=.

  Finally, the last block group may be smaller than the rest, so account
  for this on the last pass through: last_block = sb->s_blocks_count - 1;

Signed-off-by: Eric Sandeen <[e-mail]>
Cc: Mingming Cao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

Index: linux-2.6.17-1.2654.el5/fs/ext3/super.c
===================================================================
--- linux-2.6.17-1.2654.el5.orig/fs/ext3/super.c
+++ linux-2.6.17-1.2654.el5/fs/ext3/super.c
@@ -1132,7 +1132,8 @@ static int ext3_setup_super(struct super
 static int ext3_check_descriptors (struct super_block * sb)
 {
 	struct ext3_sb_info *sbi = EXT3_SB(sb);
-	ext3_fsblk_t block = le32_to_cpu(sbi->s_es->s_first_data_block);
+	ext3_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+	ext3_fsblk_t last_block;
 	struct ext3_group_desc * gdp = NULL;
 	int desc_block = 0;
 	int i;
@@ -1141,12 +1142,17 @@ static int ext3_check_descriptors (struc
 
 	for (i = 0; i < sbi->s_groups_count; i++)
 	{
+		if (i == sbi->s_groups_count - 1)
+			last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
+		else
+			last_block = first_block +
+				(EXT3_BLOCKS_PER_GROUP(sb) - 1);
+
 		if ((i % EXT3_DESC_PER_BLOCK(sb)) == 0)
 			gdp = (struct ext3_group_desc *)
 					sbi->s_group_desc[desc_block++]->b_data;
-		if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
-		    le32_to_cpu(gdp->bg_block_bitmap) >=
-				block + EXT3_BLOCKS_PER_GROUP(sb))
+		if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+		    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
 		{
 			ext3_error (sb, "ext3_check_descriptors",
 				    "Block bitmap for group %d"
@@ -1155,9 +1161,8 @@ static int ext3_check_descriptors (struc
 					le32_to_cpu(gdp->bg_block_bitmap));
 			return 0;
 		}
-		if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
-		    le32_to_cpu(gdp->bg_inode_bitmap) >=
-				block + EXT3_BLOCKS_PER_GROUP(sb))
+		if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+		    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
 		{
 			ext3_error (sb, "ext3_check_descriptors",
 				    "Inode bitmap for group %d"
@@ -1166,9 +1171,9 @@ static int ext3_check_descriptors (struc
 					le32_to_cpu(gdp->bg_inode_bitmap));
 			return 0;
 		}
-		if (le32_to_cpu(gdp->bg_inode_table) < block ||
-		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
-		    block + EXT3_BLOCKS_PER_GROUP(sb))
+		if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+		    le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
+		    last_block)
 		{
 			ext3_error (sb, "ext3_check_descriptors",
 				    "Inode table for group %d"
@@ -1177,7 +1182,7 @@ static int ext3_check_descriptors (struc
 					le32_to_cpu(gdp->bg_inode_table));
 			return 0;
 		}
-		block += EXT3_BLOCKS_PER_GROUP(sb);
+		first_block += EXT3_BLOCKS_PER_GROUP(sb);
 		gdp++;
 	}
 
@@ -1580,10 +1585,9 @@ static int ext3_fill_super (struct super
 
 	if (EXT3_BLOCKS_PER_GROUP(sb) == 0)
 		goto cantfind_ext3;
-	sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
-			       le32_to_cpu(es->s_first_data_block) +
-			       EXT3_BLOCKS_PER_GROUP(sb) - 1) /
-			      EXT3_BLOCKS_PER_GROUP(sb);
+	sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+			       le32_to_cpu(es->s_first_data_block) - 1)
+				       / EXT3_BLOCKS_PER_GROUP(sb)) + 1;
 	db_count = (sbi->s_groups_count + EXT3_DESC_PER_BLOCK(sb) - 1) /
 		   EXT3_DESC_PER_BLOCK(sb);
 	sbi->s_group_desc = kmalloc(db_count * sizeof (struct buffer_head *),

Date: Tue, 19 Sep 2006 15:32:42 -0500
From: Eric Sandeen <[e-mail]>
Subject: [RHEL5 Patch 2/3] (resend) Fix more ext3 overflows at 16T

This is in akpm's tree as
more-ext3-16t-overflow-fixes.patch and more-ext3-16t-overflow-fixes-fix.patch

Some of the changes in balloc.c are just cosmetic -
if they overflow they'll then underflow and things are fine.

5th hunk actually fixes an overflow problem.

Also check for potential overflows in inode & block counts when resizing.

Signed-off-by: Eric Sandeen <[e-mail]>
Cc: Mingming Cao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

Index: linux-2.6.17-1.2654.el5/fs/ext3/balloc.c
===================================================================
--- linux-2.6.17-1.2654.el5.orig/fs/ext3/balloc.c
+++ linux-2.6.17-1.2654.el5/fs/ext3/balloc.c
@@ -168,7 +168,7 @@ goal_in_my_reservation(struct ext3_reser
 	ext3_fsblk_t group_first_block, group_last_block;
 
 	group_first_block = ext3_group_first_block_no(sb, group);
-	group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+	group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	if ((rsv->_rsv_start > group_last_block) ||
 	    (rsv->_rsv_end < group_first_block))
@@ -897,7 +897,7 @@ static int alloc_new_reservation(struct 
 	spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
 
 	group_first_block = ext3_group_first_block_no(sb, group);
-	group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+	group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	if (grp_goal < 0)
 		start_block = group_first_block;
@@ -1063,7 +1063,7 @@ ext3_try_to_allocate_with_rsv(struct sup
 			struct ext3_reserve_window_node * my_rsv,
 			unsigned long *count, int *errp)
 {
-	ext3_fsblk_t group_first_block;
+	ext3_fsblk_t group_first_block, group_last_block;
 	ext3_grpblk_t ret = 0;
 	int fatal;
 	unsigned long num = *count;
@@ -1100,6 +1100,7 @@ ext3_try_to_allocate_with_rsv(struct sup
 	 * first block is the block number of the first block in this group
 	 */
 	group_first_block = ext3_group_first_block_no(sb, group);
+	group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
 
 	/*
 	 * Basically we will allocate a new block from inode's reservation
@@ -1132,8 +1133,8 @@ ext3_try_to_allocate_with_rsv(struct sup
 			try_to_extend_reservation(my_rsv, sb,
 					*count-my_rsv->rsv_end + grp_goal - 1);
 
-		if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
-		    || (my_rsv->rsv_end < group_first_block))
+		if ((my_rsv->rsv_start > group_last_block) ||
+				(my_rsv->rsv_end < group_first_block))
 			BUG();
 		ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, grp_goal,
 					   &num, &my_rsv->rsv_window);
Index: linux-2.6.17-1.2654.el5/fs/ext3/resize.c
===================================================================
--- linux-2.6.17-1.2654.el5.orig/fs/ext3/resize.c
+++ linux-2.6.17-1.2654.el5/fs/ext3/resize.c
@@ -730,6 +730,18 @@ int ext3_group_add(struct super_block *s
 		return -EPERM;
 	}
 
+	if (le32_to_cpu(es->s_blocks_count) + input->blocks_count <
+	    le32_to_cpu(es->s_blocks_count)) {
+		ext3_warning(sb, __FUNCTION__, "blocks_count overflow\n");
+		return -EINVAL;
+	}
+
+	if (le32_to_cpu(es->s_inodes_count) + EXT3_INODES_PER_GROUP(sb) <
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext3_warning(sb, __FUNCTION__, "inodes_count overflow\n");
+		return -EINVAL;
+	}
+
 	if (reserved_gdb || gdb_off == 0) {
 		if (!EXT3_HAS_COMPAT_FEATURE(sb,
 					     EXT3_FEATURE_COMPAT_RESIZE_INODE)){
@@ -958,6 +970,11 @@ int ext3_group_extend(struct super_block
 
 	add = EXT3_BLOCKS_PER_GROUP(sb) - last;
 
+	if (o_blocks_count + add < o_blocks_count) {
+		ext3_warning(sb, __FUNCTION__, "blocks_count overflow");
+		return -EINVAL;
+	}
+
 	if (o_blocks_count + add > n_blocks_count)
 		add = n_blocks_count - o_blocks_count;