exfat: reduce FAT chain traversal

Before this commit, ->dir and ->entry of exfat_inode_info record the
first cluster of the parent directory and the directory entry index
starting from this cluster.

The directory entry set will be gotten during write-back-inode/rmdir/
unlink/rename. If the clusters of the parent directory are not
continuous, the FAT chain will be traversed from the first cluster of
the parent directory to find the cluster where ->entry is located.

After this commit, ->dir records the cluster where the first directory
entry in the directory entry set is located, and ->entry records the
directory entry index in the cluster, so that there is almost no need
to access the FAT when getting the directory entry set.

Signed-off-by: Yuezhang Mo <[email protected]>
Reviewed-by: Aoyama Wataru <[email protected]>
Reviewed-by: Daniel Palmer <[email protected]>
Reviewed-by: Sungjong Seo <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>

0 files changed, 0 insertions, 0 deletions