Merge branch 'maint' into next

[tools/e2fsprogs.git] / lib / ext2fs / initialize.c

diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index 75fbf8e..34753d0 100644 (file)
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -91,8 +91,10 @@ errcode_t ext2fs_initialize(const char *name, int flags,
        unsigned int    rem;
        unsigned int    overhead = 0;
        unsigned int    ipg;
+       unsigned int    flexbg_size;
        dgrp_t          i;
        blk64_t         free_blocks;
+       blk64_t         flexbg_overhead;
        blk_t           numblocks;
        int             rsv_gdt;
        int             csum_flag;
@@ -419,6 +421,28 @@ ipg_retry:
        }
 
        /*
+        * Calculate the flex_bg related metadata blocks count.
+        * It includes the boot block, the super block,
+        * the block group descriptors, the reserved gdt blocks,
+        * the block bitmaps, the inode bitmaps and the inode tables.
+        * This is a simple check, so that the backup superblock and
+        * other feature related blocks are not considered.
+        */
+       flexbg_size = 1 << fs->super->s_log_groups_per_flex;
+       flexbg_overhead = super->s_first_data_block + 1 +
+               fs->desc_blocks + super->s_reserved_gdt_blocks +
+               (__u64)flexbg_size * (2 + fs->inode_blocks_per_group);
+
+       /*
+        * Disallow creating ext4 which breaks flex_bg metadata layout
+        * obviously.
+        */
+       if (flexbg_overhead > ext2fs_blocks_count(fs->super)) {
+               retval = EXT2_ET_INVALID_ARGUMENT;
+               goto cleanup;
+       }
+
+       /*
         * At this point we know how big the filesystem will be.  So
         * we can do any and all allocations that depend on the block
         * count.