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Diffstat (limited to 'Documentation/filesystems/f2fs.txt')
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index 13c2ff034348..12a147c9f87f 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -174,6 +174,23 @@ offgrpjquota Turn off group journelled quota. offprjjquota Turn off project journelled quota. quota Enable plain user disk quota accounting. noquota Disable all plain disk quota option. +whint_mode=%s Control which write hints are passed down to block + layer. This supports "off", "user-based", and + "fs-based". In "off" mode (default), f2fs does not pass + down hints. In "user-based" mode, f2fs tries to pass + down hints given by users. And in "fs-based" mode, f2fs + passes down hints with its policy. +alloc_mode=%s Adjust block allocation policy, which supports "reuse" + and "default". +fsync_mode=%s Control the policy of fsync. Currently supports "posix" + and "strict". In "posix" mode, which is default, fsync + will follow POSIX semantics and does a light operation + to improve the filesystem performance. In "strict" mode, + fsync will be heavy and behaves in line with xfs, ext4 + and btrfs, where xfstest generic/342 will pass, but the + performance will regress. +test_dummy_encryption Enable dummy encryption, which provides a fake fscrypt + context. The fake fscrypt context is used by xfstests. ================================================================================ DEBUGFS ENTRIES @@ -611,3 +628,63 @@ algorithm. In order to identify whether the data in the victim segment are valid or not, F2FS manages a bitmap. Each bit represents the validity of a block, and the bitmap is composed of a bit stream covering whole blocks in main area. + +Write-hint Policy +----------------- + +1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET. + +2) whint_mode=user-based. F2FS tries to pass down hints given by +users. + +User F2FS Block +---- ---- ----- + META WRITE_LIFE_NOT_SET + HOT_NODE " + WARM_NODE " + COLD_NODE " +*ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME +*extension list " " + +-- buffered io +WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME +WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT +WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET +WRITE_LIFE_NONE " " +WRITE_LIFE_MEDIUM " " +WRITE_LIFE_LONG " " + +-- direct io +WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME +WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT +WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET +WRITE_LIFE_NONE " WRITE_LIFE_NONE +WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM +WRITE_LIFE_LONG " WRITE_LIFE_LONG + +3) whint_mode=fs-based. F2FS passes down hints with its policy. + +User F2FS Block +---- ---- ----- + META WRITE_LIFE_MEDIUM; + HOT_NODE WRITE_LIFE_NOT_SET + WARM_NODE " + COLD_NODE WRITE_LIFE_NONE +ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME +extension list " " + +-- buffered io +WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME +WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT +WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_LONG +WRITE_LIFE_NONE " " +WRITE_LIFE_MEDIUM " " +WRITE_LIFE_LONG " " + +-- direct io +WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME +WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT +WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET +WRITE_LIFE_NONE " WRITE_LIFE_NONE +WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM +WRITE_LIFE_LONG " WRITE_LIFE_LONG |