Re: [U-Boot] [PATCH 2/7] ext4: determine group descriptor size for 64bit feature

Hi Stefan, Tom,

I'm using genext2fs command in Linux to generate my boot image for kernel and its dtb, my command is like this: $ genext2fs -b 32768 -B $((32*1024*1024/32768)) -d boot/ -i 8192 -U boot.img

In the latest version of U-Boot, the image from above command is not able to be mount. After debug, I found out that the root cause is that the genext2fs does not have a initial value for revision_level in super block. After I do the mount and umount for the image in Linux, the U-Boot then can mount the image.

Is it possible to still support the ext2 image generated by genext2fs command in U-Boot?

Thanks, - Kever On 09/17/2016 08:10 AM, Stefan Brüns wrote:

If EXT4_FEATURE_INCOMPAT_64BIT is set, the descriptor can be read from the superblocks, otherwise it defaults to 32.

Signed-off-by: Stefan Brüns stefan.bruens@rwth-aachen.de

fs/ext4/ext4_common.c | 18 ++++++++++++++---- include/ext4fs.h | 2 ++ 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index a78b0b8..416a9db 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -2233,13 +2233,23 @@ int ext4fs_mount(unsigned part_length) goto fail; }

• if (le32_to_cpu(data->sblock.revision_level) == 0)

• if (le32_to_cpu(data->sblock.revision_level) == 0) { fs->inodesz = 128;

• else

• } else {

• debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
  

•       __le32_to_cpu(data->sblock.feature_compatibility),
  

•       __le32_to_cpu(data->sblock.feature_incompat),
  

•       __le32_to_cpu(data->sblock.feature_ro_compat));
  

• fs->inodesz = le16_to_cpu(data->sblock.inode_size);

• fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
  

• 	EXT4_FEATURE_INCOMPAT_64BIT ?
  

• 	le16_to_cpu(data->sblock.descriptor_size) : 32;
  

• }

• debug("EXT2 rev %d, inode_size %d\n",

•       le32_to_cpu(data->sblock.revision_level), fs->inodesz);
  

• debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",

•      le32_to_cpu(data->sblock.revision_level),
  

•      fs->inodesz, fs->gdsize);
  
  

  data->diropen.data = data; data->diropen.ino = 2;

diff --git a/include/ext4fs.h b/include/ext4fs.h index 6e31c73..7e1ee6c 100644 --- a/include/ext4fs.h +++ b/include/ext4fs.h @@ -87,6 +87,8 @@ struct ext_filesystem { uint32_t inodesz; /* Sectors per Block */ uint32_t sect_perblk;

• /* Group Descriptor size */
• uint16_t gdsize; /* Group Descriptor Block Number */ uint32_t gdtable_blkno; /* Total block groups of partition */