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| author | Daeho Jeong <daehojeong@google.com> | 2021-09-29 20:12:03 +0200 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2021-10-26 23:04:30 +0200 |
| commit | 6691d940b0e09dd1564130e7a354d6deaf05d009 (patch) | |
| tree | ae609ea58abdfd7ce7c73e72f82d39226f2de3a9 /fs/f2fs/segment.h | |
| parent | f2fs: replace snprintf in show functions with sysfs_emit (diff) | |
| download | linux-6691d940b0e09dd1564130e7a354d6deaf05d009.tar.xz linux-6691d940b0e09dd1564130e7a354d6deaf05d009.zip | |
f2fs: introduce fragment allocation mode mount option
Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.
"fragment:segment": f2fs allocates a new segment in ramdom position.
With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
"max_fragment_chunk" and "max_fragment_hole" sysfs
nodes. f2fs will allocate 1..<max_fragment_chunk>
blocks in a chunk and make a hole in the length of
1..<max_fragment_hole> by turns in a newly allocated
free segment. Plus, this mode implicitly enables
"fragment:segment" option for more randomness.
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/segment.h')
| -rw-r--r-- | fs/f2fs/segment.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 89fff258727d..46fde9f3f28e 100644 --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -314,6 +314,7 @@ struct curseg_info { unsigned short next_blkoff; /* next block offset to write */ unsigned int zone; /* current zone number */ unsigned int next_segno; /* preallocated segment */ + int fragment_remained_chunk; /* remained block size in a chunk for block fragmentation mode */ bool inited; /* indicate inmem log is inited */ }; |