diff mbox series

[6/8] erofs: get rid of fe->backmost for cache decompression

Message ID 20230817082813.81180-6-hsiangkao@linux.alibaba.com
State New
Headers
Series [1/8] erofs: simplify z_erofs_read_fragment() |

Commit Message

Gao Xiang Aug. 17, 2023, 8:28 a.m. UTC 
  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 <hsiangkao@linux.alibaba.com>
---
 fs/erofs/zdata.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

Comments

Gao Xiang Aug. 18, 2023, 7:48 a.m. UTC | #1 
On 2023/8/18 13:51, Yue Hu wrote:
> On Thu, 17 Aug 2023 16:28:11 +0800
> Gao Xiang <hsiangkao@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 <hsiangkao@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)?

fe->backmost is inaccurate compared with !EROFS_MAP_FULL_MAPPED,
if !EROFS_MAP_FULL_MAPPED, it should be cached instead.

Thanks,
Gao Xiang
diff mbox series

Patch

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))
 		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,