f2fs: enhance on-disk inode structure scalability
This patch add new flag F2FS_EXTRA_ATTR storing in inode.i_inline
to indicate that on-disk structure of current inode is extended.
In order to extend, we changed the inode structure a bit:
Original one:
struct f2fs_inode {
...
struct f2fs_extent i_ext;
__le32 i_addr[DEF_ADDRS_PER_INODE];
__le32 i_nid[DEF_NIDS_PER_INODE];
}
Extended one:
struct f2fs_inode {
...
struct f2fs_extent i_ext;
union {
struct {
__le16 i_extra_isize;
__le16 i_padding;
__le32 i_extra_end[0];
};
__le32 i_addr[DEF_ADDRS_PER_INODE];
};
__le32 i_nid[DEF_NIDS_PER_INODE];
}
Once F2FS_EXTRA_ATTR is set, we will steal four bytes in the head of
i_addr field for storing i_extra_isize and i_padding. with i_extra_isize,
we can calculate actual size of reserved space in i_addr, available
attribute fields included in total extra attribute fields for current
inode can be described as below:
+--------------------+
| .i_mode |
| ... |
| .i_ext |
+--------------------+
| .i_extra_isize |-----+
| .i_padding | |
| .i_prjid | |
| .i_atime_extra | |
| .i_ctime_extra | |
| .i_mtime_extra |<----+
| .i_inode_cs |<----- store blkaddr/inline from here
| .i_xattr_cs |
| ... |
+--------------------+
| |
| block address |
| |
+--------------------+
| .i_nid |
+--------------------+
| node_footer |
| (nid, ino, offset) |
+--------------------+
Hence, with this patch, we would enhance scalability of f2fs inode for
storing more newly added attribute.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 530c703..4233774 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -447,8 +447,6 @@
/* Will be used by directory only */
fi->i_dir_level = F2FS_SB(sb)->dir_level;
- fi->i_inline_reserved = DEF_INLINE_RESERVED_SIZE;
-
return &fi->vfs_inode;
}
@@ -1306,9 +1304,16 @@
static loff_t max_file_blocks(void)
{
- loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
+ loff_t result = 0;
loff_t leaf_count = ADDRS_PER_BLOCK;
+ /*
+ * note: previously, result is equal to (DEF_ADDRS_PER_INODE -
+ * F2FS_INLINE_XATTR_ADDRS), but now f2fs try to reserve more
+ * space in inode.i_addr, it will be more safe to reassign
+ * result as zero.
+ */
+
/* two direct node blocks */
result += (leaf_count * 2);