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authorJaegeuk Kim <jaegeuk@kernel.org>2024-04-17 23:01:55 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2024-04-19 20:56:13 +0300
commit7643f3fe27729b20e6fcf6b314b00b8b93504356 (patch)
tree42ef1e80c57a604345d02f4d8fd3c07b02573e9b /Documentation/filesystems
parentb2cf5a1ff236fcd0eb9dcbb188df30b50bb1af0f (diff)
downloadlinux-7643f3fe27729b20e6fcf6b314b00b8b93504356.tar.xz
f2fs: assign the write hint per stream by default
This reverts commit 930e2607638d ("f2fs: remove obsolete whint_mode"), as we decide to pass write hints to the disk. Cc: Hyunchul Lee <cheol.lee@lge.com> Signed-off-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.rst29
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index efc3493fd6f8..68a0885fb5e6 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -774,6 +774,35 @@ 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
+-----------------
+
+F2FS sets the whint all the time with the below policy.
+
+===================== ======================== ===================
+User F2FS Block
+===================== ======================== ===================
+N/A META WRITE_LIFE_NONE|REQ_META
+N/A HOT_NODE WRITE_LIFE_NONE
+N/A WARM_NODE WRITE_LIFE_MEDIUM
+N/A COLD_NODE WRITE_LIFE_LONG
+ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
+extension list " "
+
+-- buffered io
+N/A COLD_DATA WRITE_LIFE_EXTREME
+N/A HOT_DATA WRITE_LIFE_SHORT
+N/A WARM_DATA WRITE_LIFE_NOT_SET
+
+-- 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
+===================== ======================== ===================
+
Fallocate(2) Policy
-------------------