linux.git/fs/f2fs/extent_cache.c, branch v6.2-rc2

f2fs: add block_age-based extent cache

2022-12-12T22:53:56+00:00

This patch introduces a runtime hot/cold data separation method
for f2fs, in order to improve the accuracy for data temperature
classification, reduce the garbage collection overhead after
long-term data updates.

Enhanced hot/cold data separation can record data block update
frequency as "age" of the extent per inode, and take use of the age
info to indicate better temperature type for data block allocation:
 - It records total data blocks allocated since mount;
 - When file extent has been updated, it calculate the count of data
blocks allocated since last update as the age of the extent;
 - Before the data block allocated, it searches for the age info and
chooses the suitable segment for allocation.

Test and result:
 - Prepare: create about 30000 files
  * 3% for cold files (with cold file extension like .apk, from 3M to 10M)
  * 50% for warm files (with random file extension like .FcDxq, from 1K
to 4M)
  * 47% for hot files (with hot file extension like .db, from 1K to 256K)
 - create(5%)/random update(90%)/delete(5%) the files
  * total write amount is about 70G
  * fsync will be called for .db files, and buffered write will be used
for other files

The storage of test device is large enough(128G) so that it will not
switch to SSR mode during the test.

Benefit: dirty segment count increment reduce about 14%
 - before: Dirty +21110
 - after:  Dirty +18286

Signed-off-by: qixiaoyu1 
Signed-off-by: xiongping1 
Signed-off-by: Jaegeuk Kim

f2fs: allocate the extent_cache by default

2022-12-12T22:53:56+00:00

Let's allocate it to remove the runtime complexity.

Signed-off-by: Jaegeuk Kim

f2fs: refactor extent_cache to support for read and more

2022-12-12T22:53:56+00:00

This patch prepares extent_cache to be ready for addition.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: remove unnecessary __init_extent_tree

2022-12-12T22:53:56+00:00

Added into the caller.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: move internal functions into extent_cache.c

2022-12-12T22:53:55+00:00

No functional change.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: specify extent cache for read explicitly

2022-12-12T22:53:55+00:00

Let's descrbie it's read extent cache.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: code clean and fix a type error

2022-10-04T20:31:44+00:00

ERROR: code indent should use tabs where possible
ERROR: spaces required around that ':'
ERROR: incorrect tab

Found serveral code type errors when review the code and fix it.
There is no function change.

Signed-off-by: Zhang Qilong 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: add "c_len" into trace_f2fs_update_extent_tree_range for compressed file

2022-10-04T20:31:43+00:00

The trace_f2fs_update_extent_tree_range could not record compressed
block length in the cluster of compress file and we just add it.

Signed-off-by: Zhang Qilong 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix race condition on setting FI_NO_EXTENT flag

2022-10-04T20:31:43+00:00

The following scenarios exist.
process A:               process B:
->f2fs_drop_extent_tree  ->f2fs_update_extent_cache_range
                          ->f2fs_update_extent_tree_range
                           ->write_lock
 ->set_inode_flag
                           ->is_inode_flag_set
                           ->__free_extent_tree // Shouldn't
                                                // have been
                                                // cleaned up
                                                // here
  ->write_lock

In this case, the "FI_NO_EXTENT" flag is set between
f2fs_update_extent_tree_range and is_inode_flag_set
by other process. it leads to clearing the whole exten
tree which should not have happened. And we fix it by
move the setting it to the range of write_lock.

Fixes:5f281fab9b9a3 ("f2fs: disable extent_cache for fcollapse/finsert inodes")
Signed-off-by: Zhang Qilong 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: support fault injection for f2fs_kmem_cache_alloc()

2021-08-17T18:59:05+00:00

This patch supports to inject fault into f2fs_kmem_cache_alloc().

Usage:
a) echo 32768 > /sys/fs/f2fs//inject_type or
b) mount -o fault_type=32768  

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim