On Thu, 17 Aug 2023 16:28:11 +0800
Gao Xiang <hsiang...@linux.alibaba.com> wrote:
> EROFS_MAP_FULL_MAPPED is more accurate to decide if caching the last
> incomplete pcluster for later read or not.
>
> Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
> ---
> fs/erofs/zdata.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index 4009283944ca..c28945532a02 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -528,8 +528,6 @@ struct z_erofs_decompress_frontend {
> z_erofs_next_pcluster_t owned_head;
> enum z_erofs_pclustermode mode;
>
> - /* used for applying cache strategy on the fly */
> - bool backmost;
> erofs_off_t headoffset;
>
> /* a pointer used to pick up inplace I/O pages */
> @@ -538,7 +536,7 @@ struct z_erofs_decompress_frontend {
>
> #define DECOMPRESS_FRONTEND_INIT(__i) { \
> .inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \
> - .mode = Z_EROFS_PCLUSTER_FOLLOWED, .backmost = true }
> + .mode = Z_EROFS_PCLUSTER_FOLLOWED }
>
> static bool z_erofs_should_alloc_cache(struct z_erofs_decompress_frontend
> *fe)
> {
> @@ -547,7 +545,7 @@ static bool z_erofs_should_alloc_cache(struct
> z_erofs_decompress_frontend *fe)
> if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
> return false;
>
> - if (fe->backmost)
> + if (!(fe->map.m_flags & EROFS_MAP_FULL_MAPPED))
So, i understand (map.m_flags & EROFS_MAP_FULL_MAPPED) should be false if
allocate cache is needed
(fe->backmost is true)?
> return true;
>
> if (cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
> @@ -939,7 +937,6 @@ static void z_erofs_pcluster_end(struct
> z_erofs_decompress_frontend *fe)
> erofs_workgroup_put(&pcl->obj);
>
> fe->pcl = NULL;
> - fe->backmost = false;
> }
>
> static int z_erofs_read_fragment(struct super_block *sb, struct page *page,
