[PATCH] ext2: fix mounts at 16T

Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 19 insertions, 13 deletions

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 4286ff6330b6..d978d3febb8c 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -544,17 +544,24 @@ static int ext2_check_descriptors (struct super_block * sb)
         int i;
         int desc_block = 0;
         struct ext2_sb_info *sbi = EXT2_SB(sb);
-        unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+        unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+        unsigned long last_block;
         struct ext2_group_desc * gdp = NULL;
 
         ext2_debug ("Checking group descriptors");
 
         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 +
+                                (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
                 if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
                         gdp = (struct ext2_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 + EXT2_BLOCKS_PER_GROUP(sb))
+                if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+                    le32_to_cpu(gdp->bg_block_bitmap) > last_block)
                 {
                         ext2_error (sb, "ext2_check_descriptors",
                                     "Block bitmap for group %d"
@@ -562,8 +569,8 @@ static int ext2_check_descriptors (struct super_block * sb)
                                     i, (unsigned long) 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 + EXT2_BLOCKS_PER_GROUP(sb))
+                if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+                    le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
                 {
                         ext2_error (sb, "ext2_check_descriptors",
                                     "Inode bitmap for group %d"
@@ -571,9 +578,9 @@ static int ext2_check_descriptors (struct super_block * sb)
                                     i, (unsigned long) 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 + EXT2_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)
                 {
                         ext2_error (sb, "ext2_check_descriptors",
                                     "Inode table for group %d"
@@ -581,7 +588,7 @@ static int ext2_check_descriptors (struct super_block * sb)
                                     i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
                         return 0;
                 }
-                block += EXT2_BLOCKS_PER_GROUP(sb);
+                first_block += EXT2_BLOCKS_PER_GROUP(sb);
                 gdp++;
         }
         return 1;
@@ -861,10 +868,9 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 
         if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
                 goto cantfind_ext2;
-        sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
-                                        le32_to_cpu(es->s_first_data_block) +
-                                       EXT2_BLOCKS_PER_GROUP(sb) - 1) /
-                                       EXT2_BLOCKS_PER_GROUP(sb);
+        sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+                                le32_to_cpu(es->s_first_data_block) - 1)
+                                        / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
         db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
                    EXT2_DESC_PER_BLOCK(sb);
         sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);