ext4: determine group descriptor size for 64bit feature
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>
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 5f21dc7..2df4f8b 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -2233,13 +2233,23 @@
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 @@
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 */