[PATCH] ext4: allow larger descriptor size
make block group descriptor larger.
Signed-off-by: Alexandre Ratchov <alexandre.ratchov@bull.net>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index df77ea8..3dacb12 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -74,10 +74,12 @@
return NULL;
}
- desc = (struct ext4_group_desc *) sbi->s_group_desc[group_desc]->b_data;
+ desc = (struct ext4_group_desc *)(
+ (__u8 *)sbi->s_group_desc[group_desc]->b_data +
+ offset * EXT4_DESC_SIZE(sb));
if (bh)
*bh = sbi->s_group_desc[group_desc];
- return desc + offset;
+ return desc;
}
/**
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c05dc57..d03e7d8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2432,14 +2432,16 @@
return 0;
}
- gdp = (struct ext4_group_desc *)bh->b_data;
+ gdp = (struct ext4_group_desc *)((__u8 *)bh->b_data +
+ desc * EXT4_DESC_SIZE(sb));
/*
* Figure out the offset within the block group inode table
*/
offset = ((ino - 1) % EXT4_INODES_PER_GROUP(sb)) *
EXT4_INODE_SIZE(sb);
- block = ext4_inode_table(gdp + desc) +
- (offset >> EXT4_BLOCK_SIZE_BITS(sb));
+ block = ext4_inode_table(gdp) + (offset >> EXT4_BLOCK_SIZE_BITS(sb));
+
+
iloc->block_group = block_group;
iloc->offset = offset & (EXT4_BLOCK_SIZE(sb) - 1);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d844175..bc8848b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1268,7 +1268,8 @@
return 0;
}
first_block += EXT4_BLOCKS_PER_GROUP(sb);
- gdp++;
+ gdp = (struct ext4_group_desc *)
+ ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
}
ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
@@ -1619,7 +1620,18 @@
sbi->s_frag_size, blocksize);
goto failed_mount;
}
- sbi->s_frags_per_block = 1;
+ sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
+ if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE ||
+ sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
+ sbi->s_desc_size & (sbi->s_desc_size - 1)) {
+ printk(KERN_ERR
+ "EXT4-fs: unsupported descriptor size %ld\n",
+ sbi->s_desc_size);
+ goto failed_mount;
+ }
+ } else
+ sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group);
sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
@@ -1630,7 +1642,7 @@
goto cantfind_ext4;
sbi->s_itb_per_group = sbi->s_inodes_per_group /
sbi->s_inodes_per_block;
- sbi->s_desc_per_block = blocksize / sizeof(struct ext4_group_desc);
+ sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
sbi->s_sbh = bh;
sbi->s_mount_state = le16_to_cpu(es->s_state);
sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index 8e5009e..a3df2af 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -142,6 +142,9 @@
/*
* Macro-instructions used to manage group descriptors
*/
+#define EXT4_MIN_DESC_SIZE 32
+#define EXT4_MAX_DESC_SIZE EXT4_MIN_BLOCK_SIZE
+#define EXT4_DESC_SIZE(s) (EXT4_SB(s)->s_desc_size)
#ifdef __KERNEL__
# define EXT4_BLOCKS_PER_GROUP(s) (EXT4_SB(s)->s_blocks_per_group)
# define EXT4_DESC_PER_BLOCK(s) (EXT4_SB(s)->s_desc_per_block)
@@ -149,7 +152,7 @@
# define EXT4_DESC_PER_BLOCK_BITS(s) (EXT4_SB(s)->s_desc_per_block_bits)
#else
# define EXT4_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
-# define EXT4_DESC_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / sizeof (struct ext4_group_desc))
+# define EXT4_DESC_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
# define EXT4_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
#endif
@@ -474,7 +477,7 @@
* things it doesn't understand...
*/
__le32 s_first_ino; /* First non-reserved inode */
- __le16 s_inode_size; /* size of inode structure */
+ __le16 s_inode_size; /* size of inode structure */
__le16 s_block_group_nr; /* block group # of this superblock */
__le32 s_feature_compat; /* compatible feature set */
/*60*/ __le32 s_feature_incompat; /* incompatible feature set */
@@ -500,7 +503,7 @@
__le32 s_hash_seed[4]; /* HTREE hash seed */
__u8 s_def_hash_version; /* Default hash version to use */
__u8 s_reserved_char_pad;
- __u16 s_reserved_word_pad;
+ __le16 s_desc_size; /* size of group descriptor */
/*100*/ __le32 s_default_mount_opts;
__le32 s_first_meta_bg; /* First metablock block group */
__le32 s_mkfs_time; /* When the filesystem was created */
diff --git a/include/linux/ext4_fs_sb.h b/include/linux/ext4_fs_sb.h
index ce7a844..691a713 100644
--- a/include/linux/ext4_fs_sb.h
+++ b/include/linux/ext4_fs_sb.h
@@ -29,6 +29,7 @@
*/
struct ext4_sb_info {
unsigned long s_frag_size; /* Size of a fragment in bytes */
+ unsigned long s_desc_size; /* Size of a group descriptor in bytes */
unsigned long s_frags_per_block;/* Number of fragments per block */
unsigned long s_inodes_per_block;/* Number of inodes per block */
unsigned long s_frags_per_group;/* Number of fragments in a group */