Hi Bean,
Bean <[EMAIL PROTECTED]> writes:
> This patch add support for extents in ext4.
This is really great! :D
Can you also provide a changelog entry?
> diff --git a/fs/ext2.c b/fs/ext2.c
> index 22fd272..3518dcf 100644
> --- a/fs/ext2.c
> +++ b/fs/ext2.c
> @@ -86,6 +86,8 @@
> #define EXT3_JOURNAL_FLAG_DELETED 4
> #define EXT3_JOURNAL_FLAG_LAST_TAG 8
>
> +#define EXT4_EXTENTS_FLAG 0x80000
> +
> /* The ext2 superblock. */
> struct grub_ext2_sblock
> {
> @@ -226,6 +228,33 @@ struct grub_ext3_journal_sblock
> grub_uint32_t start;
> };
>
> +#define EXT4_EXT_MAGIC 0xf30a
> +
> +struct grub_ext4_extent_header
> +{
> + grub_uint16_t magic;
> + grub_uint16_t entries;
> + grub_uint16_t max;
> + grub_uint16_t depth;
> + grub_uint32_t generation;
> +};
> +
> +struct grub_ext4_extent
> +{
> + grub_uint32_t block;
> + grub_uint16_t len;
> + grub_uint16_t start_hi;
> + grub_uint32_t start;
> +};
> +
> +struct grub_ext4_extent_idx
> +{
> + grub_uint32_t block;
> + grub_uint32_t leaf;
> + grub_uint16_t leaf_hi;
> + grub_uint16_t unused;
> +};
> +
> struct grub_fshelp_node
> {
> struct grub_ext2_data *data;
> @@ -262,6 +291,46 @@ grub_ext2_blockgroup (struct grub_ext2_data *data, int
> group,
> sizeof (struct grub_ext2_block_group), (char *)
> blkgrp);
> }
>
> +static struct grub_ext4_extent_header *
> +grub_ext4_find_leaf (struct grub_ext2_data *data,
> + struct grub_ext4_extent_header *ext_block,
> + grub_uint32_t fileblock)
> +{
> + char buf[EXT2_BLOCK_SIZE(data)];
> + struct grub_ext4_extent_idx *index;
> +
> + while (1)
> + {
> + int i;
> + grub_disk_addr_t block;
> +
> + index = (struct grub_ext4_extent_idx *) (ext_block + 1);
> +
> + if (grub_le_to_cpu16(ext_block->magic) != EXT4_EXT_MAGIC)
> + return 0;
> +
> + if (ext_block->depth == 0)
> + return ext_block;
> +
> + for (i = 0; i < grub_le_to_cpu16 (ext_block->entries); i++)
> + {
> + if (fileblock < grub_le_to_cpu32(index[i].block))
> + break;
> + }
> +
> + if (i == 0)
> + return 0;
> +
> + block = grub_le_to_cpu16 (index[i].leaf_hi);
> + block = (block << 32) + grub_le_to_cpu32 (index[i].leaf);
> + if (grub_disk_read (data->disk,
> + block << LOG2_EXT2_BLOCK_SIZE (data),
> + 0, sizeof (buf), buf))
> + return 0;
> +
> + ext_block = (struct grub_ext4_extent_header *) buf;
> + }
> +}
>
> static grub_disk_addr_t
> grub_ext2_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
> @@ -272,6 +341,41 @@ grub_ext2_read_block (grub_fshelp_node_t node,
> grub_disk_addr_t fileblock)
> unsigned int blksz = EXT2_BLOCK_SIZE (data);
> int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
>
> + if (inode->flags & EXT4_EXTENTS_FLAG)
> + {
> + struct grub_ext4_extent_header *leaf;
> + struct grub_ext4_extent *ext;
> + int i;
> +
> + leaf = grub_ext4_find_leaf (data,
> + (struct grub_ext4_extent_header *)
> inode->blocks.dir_blocks,
> + fileblock);
> + if (! leaf)
> + {
> + grub_error (GRUB_ERR_BAD_FS, "invalid extent");
> + return -1;
> + }
> +
> + ext = (struct grub_ext4_extent *) (leaf + 1);
> + for (i = 0; i < grub_le_to_cpu16 (leaf->entries); i++)
> + if ((fileblock >= grub_le_to_cpu32 (ext[i].block)) &&
> + (fileblock < grub_le_to_cpu32 (ext[i].block) +
> + grub_le_to_cpu16 (ext[i].len)) &&
> + ((grub_le_to_cpu16 (ext[i].len) >> 15) == 0))
> + {
> + grub_disk_addr_t start;
> +
> + start = grub_le_to_cpu16 (ext[i].start_hi);
> + start = (start << 32) + grub_le_to_cpu32 (ext[i].start);
> + return fileblock - grub_le_to_cpu32 (ext[i].block) + start;
> + }
> +
> +
> +
> + grub_printf ("HH\n");
Whoops? ;-)
> + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
> + "ext2fs doesn't support extents");
Why the error? I thought you have added extent support? Doesn't this
mean the extent has another error of some kind?
--
Marco
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