Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH] f2fs: document: add description about compressed space handling | Date | Tue, 13 Apr 2021 17:56:53 +0800 |
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User or developer may still be confused about why f2fs doesn't expose compressed space to userspace, add description about compressed space handling policy into f2fs documentation.
Signed-off-by: Chao Yu <yuchao0@huawei.com> --- Documentation/filesystems/f2fs.rst | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst index 63c0c49b726d..992bf91eeec8 100644 --- a/Documentation/filesystems/f2fs.rst +++ b/Documentation/filesystems/f2fs.rst @@ -819,6 +819,14 @@ Compression implementation * chattr +c file * chattr +c dir; touch dir/file * mount w/ -o compress_extension=ext; touch file.ext + * mount w/ -o compress_extension=*; touch any_file + +- At this point, compression feature doesn't expose compressed space to user + directly in order to guarantee potential data updates later to the space. + Instead, the main goal is to reduce data writes to flash disk as much as + possible, resulting in extending disk life time as well as relaxing IO + congestion. Alternatively, we've added ioctl interface to reclaim compressed + space and show it to user after putting the immutable bit. Compress metadata layout:: -- 2.29.2
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