On 2023/8/18 13:51, Yue Hu wrote:
> On Thu, 17 Aug 2023 16:28:11 +0800
> Gao Xiang <[email protected]> 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 <[email protected]>
>> ---
>> 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)?
fe->backmost is inaccurate compared with !EROFS_MAP_FULL_MAPPED,
if !EROFS_MAP_FULL_MAPPED, it should be cached instead.
Thanks,
Gao Xiang