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Diffstat (limited to 'Documentation/filesystems/f2fs.rst')
| -rw-r--r-- | Documentation/filesystems/f2fs.rst | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst index b8ee761c9922..dae15c96e659 100644 --- a/Documentation/filesystems/f2fs.rst +++ b/Documentation/filesystems/f2fs.rst @@ -260,6 +260,14 @@ compress_extension=%s Support adding specified extension, so that f2fs can enab For other files, we can still enable compression via ioctl. Note that, there is one reserved special extension '*', it can be set to enable compression for all files. +compress_chksum Support verifying chksum of raw data in compressed cluster. +compress_mode=%s Control file compression mode. This supports "fs" and "user" + modes. In "fs" mode (default), f2fs does automatic compression + on the compression enabled files. In "user" mode, f2fs disables + the automaic compression and gives the user discretion of + choosing the target file and the timing. The user can do manual + compression/decompression on the compression enabled files using + ioctls. inlinecrypt When possible, encrypt/decrypt the contents of encrypted files using the blk-crypto framework rather than filesystem-layer encryption. This allows the use of @@ -810,6 +818,34 @@ Compress metadata layout:: | data length | data chksum | reserved | compressed data | +-------------+-------------+----------+----------------------------+ +Compression mode +-------------------------- + +f2fs supports "fs" and "user" compression modes with "compression_mode" mount option. +With this option, f2fs provides a choice to select the way how to compress the +compression enabled files (refer to "Compression implementation" section for how to +enable compression on a regular inode). + +1) compress_mode=fs +This is the default option. f2fs does automatic compression in the writeback of the +compression enabled files. + +2) compress_mode=user +This disables the automaic compression and gives the user discretion of choosing the +target file and the timing. The user can do manual compression/decompression on the +compression enabled files using F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE +ioctls like the below. + +To decompress a file, + +fd = open(filename, O_WRONLY, 0); +ret = ioctl(fd, F2FS_IOC_DECOMPRESS_FILE); + +To compress a file, + +fd = open(filename, O_WRONLY, 0); +ret = ioctl(fd, F2FS_IOC_COMPRESS_FILE); + NVMe Zoned Namespace devices ---------------------------- |