diff options
| author | Daeho Jeong <daehojeong@google.com> | 2021-09-29 11:12:03 -0700 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2021-10-26 14:04:30 -0700 |
| commit | 6691d940b0e09dd1564130e7a354d6deaf05d009 (patch) | |
| tree | ae609ea58abdfd7ce7c73e72f82d39226f2de3a9 /fs/f2fs/f2fs.h | |
| parent | 84eab2a899f28137e51a36861ed2df9579f54ebe (diff) | |
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/f2fs.h')
| -rw-r--r-- | fs/f2fs/f2fs.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 039a229e11c9..e2a35aa3ad9a 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1287,8 +1287,10 @@ enum { }; enum { - FS_MODE_ADAPTIVE, /* use both lfs/ssr allocation */ - FS_MODE_LFS, /* use lfs allocation only */ + FS_MODE_ADAPTIVE, /* use both lfs/ssr allocation */ + FS_MODE_LFS, /* use lfs allocation only */ + FS_MODE_FRAGMENT_SEG, /* segment fragmentation mode */ + FS_MODE_FRAGMENT_BLK, /* block fragmentation mode */ }; enum { @@ -1759,6 +1761,9 @@ struct f2fs_sb_info { unsigned long seq_file_ra_mul; /* multiplier for ra_pages of seq. files in fadvise */ + int max_fragment_chunk; /* max chunk size for block fragmentation mode */ + int max_fragment_hole; /* max hole size for block fragmentation mode */ + #ifdef CONFIG_F2FS_FS_COMPRESSION struct kmem_cache *page_array_slab; /* page array entry */ unsigned int page_array_slab_size; /* default page array slab size */ @@ -3519,6 +3524,16 @@ unsigned int f2fs_usable_segs_in_sec(struct f2fs_sb_info *sbi, unsigned int f2fs_usable_blks_in_seg(struct f2fs_sb_info *sbi, unsigned int segno); +#define DEF_FRAGMENT_SIZE 4 +#define MIN_FRAGMENT_SIZE 1 +#define MAX_FRAGMENT_SIZE 512 + +static inline bool f2fs_need_rand_seg(struct f2fs_sb_info *sbi) +{ + return F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_SEG || + F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK; +} + /* * checkpoint.c */ |