[PATCH v1 0/9] Enable exfat_get_block to support obtaining multiple clusters

[Chi Zhiling <chizhiling@163.com>]

From: Chi Zhiling <chizhiling@kylinos.cn>

This patch series significantly improves exFAT read performance
by adding multi-cluster mapping support.
The changes reduce get_block calls during sequential reads,
particularly benefiting small cluster sizes.

- Extends exfat_get_cluster() and exfat_map_cluster() to handle multiple contiguous clusters
- Adds buffer head caching for FAT table reads

Performance results show ~10% improvement for 512-byte clusters (454->511 MB/s)
and reduced get_block overhead from 10.8% to 0.02% for NO_FAT_CHAIN files.

All criticism and suggestions are welcome :)

Chi Zhiling (9):
  exfat: add cache option for __exfat_ent_get
  exfat: support reuse buffer head for exfat_ent_get
  exfat: reuse cache to improve exfat_get_cluster
  exfat: improve exfat_count_num_clusters
  exfat: improve exfat_find_last_cluster
  exfat: remove unused parameters from exfat_get_cluster
  exfat: tweak exfat_cache_lookup to support zero offset cluster
  exfat: support multi-cluster for exfat_map_cluster
  exfat: support multi-cluster for exfat_get_cluster

 fs/exfat/cache.c    | 108 ++++++++++++++++++++++++++++----------------
 fs/exfat/exfat_fs.h |   7 ++-
 fs/exfat/fatent.c   |  61 ++++++++++++++++---------
 fs/exfat/inode.c    |  46 +++++++++++--------
 4 files changed, 137 insertions(+), 85 deletions(-)

-- 
2.43.0