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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 22:18:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-17 22:18:00 +0300
commitff49c86f27e4726a86f5034543e6e684daf41955 (patch)
tree6b7ee8712cba9439677a6fdb20df2b8468d65280 /Documentation/filesystems
parentb97d4c424e362ebf88fd9aa1b7ad82e3a28c26d3 (diff)
parent75e91c888989cf2df5c78b251b07de1f5052e30e (diff)
downloadlinux-ff49c86f27e4726a86f5034543e6e684daf41955.tar.xz
Merge tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim: "In this round, we've made more work into per-file compression support. For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to change the algorithm or cluster size per file. F2FS_IOC_COMPRESS | DECOMPRESS_FILE provides a way to compress and decompress the existing normal files manually. There is also a new mount option, compress_mode=fs|user, which can control who compresses the data. Chao also added a checksum feature with a mount option so that we are able to detect any corrupted cluster. In addition, Daniel contributed casefolding with encryption patch, which will be used for Android devices. Summary: Enhancements: - add ioctls and mount option to manage per-file compression feature - support casefolding with encryption - support checksum for compressed cluster - avoid IO starvation by replacing mutex with rwsem - add sysfs, max_io_bytes, to control max bio size Bug fixes: - fix use-after-free issue when compression and fsverity are enabled - fix consistency corruption during fault injection test - fix data offset for lseek - get rid of buffer_head which has 32bits limit in fiemap - fix some bugs in multi-partitions support - fix nat entry count calculation in shrinker - fix some stat information And, we've refactored some logics and fix minor bugs as well" * tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits) f2fs: compress: fix compression chksum f2fs: fix shift-out-of-bounds in sanity_check_raw_super() f2fs: fix race of pending_pages in decompression f2fs: fix to account inline xattr correctly during recovery f2fs: inline: fix wrong inline inode stat f2fs: inline: correct comment in f2fs_recover_inline_data f2fs: don't check PAGE_SIZE again in sanity_check_raw_super() f2fs: convert to F2FS_*_INO macro f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size f2fs: don't allow any writes on readonly mount f2fs: avoid race condition for shrinker count f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE f2fs: add compress_mode mount option f2fs: Remove unnecessary unlikely() f2fs: init dirty_secmap incorrectly f2fs: remove buffer_head which has 32bits limit f2fs: fix wrong block count instead of bytes f2fs: use new conversion functions between blks and bytes f2fs: rename logical_to_blk and blk_to_logical f2fs: fix kbytes written stat for multi-device case ...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.rst36
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
----------------------------