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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-09 09:37:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-09 09:37:56 -0700
commit227c4d507c71acb7bece298a98d83e5b44433f62 (patch)
tree4530225b123b33dac28c02b135912af6663685ab /Documentation/filesystems
parentbd9c3506032983d7bc3245015951db0aad9e6e3d (diff)
parent28607bf3aa6f9762b32dc7f1ed0488823c0651b8 (diff)
Merge tag 'f2fs-for-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim: "In this round, we've improved the compression support especially for Android such as allowing compression for mmap files, replacing the immutable bit with internal bit to prohibits data writes explicitly, and adding a mount option, "compress_cache", to improve random reads. And, we added "readonly" feature to compact the partition w/ compression enabled, which will be useful for Android RO partitions. Enhancements: - support compression for mmap file - use an f2fs flag instead of IMMUTABLE bit for compression - support RO feature w/ extent_cache - fully support swapfile with file pinning - improve atgc tunability - add nocompress extensions to unselect files for compression Bug fixes: - fix false alaram on iget failure during GC - fix race condition on global pointers when there are multiple f2fs instances - add MODULE_SOFTDEP for initramfs As usual, we've also cleaned up some places for better code readability (e.g., sysfs/feature, debugging messages, slab cache name, and docs)" * tag 'f2fs-for-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (32 commits) f2fs: drop dirty node pages when cp is in error status f2fs: initialize page->private when using for our internal use f2fs: compress: add nocompress extensions support MAINTAINERS: f2fs: update my email address f2fs: remove false alarm on iget failure during GC f2fs: enable extent cache for compression files in read-only f2fs: fix to avoid adding tab before doc section f2fs: introduce f2fs_casefolded_name slab cache f2fs: swap: support migrating swapfile in aligned write mode f2fs: swap: remove dead codes f2fs: compress: add compress_inode to cache compressed blocks f2fs: clean up /sys/fs/f2fs/<disk>/features f2fs: add pin_file in feature list f2fs: Advertise encrypted casefolding in sysfs f2fs: Show casefolding support only when supported f2fs: support RO feature f2fs: logging neatening f2fs: introduce FI_COMPRESS_RELEASED instead of using IMMUTABLE bit f2fs: compress: remove unneeded preallocation f2fs: atgc: export entries for better tunability via sysfs ...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/f2fs.rst50
1 files changed, 41 insertions, 9 deletions
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 992bf91eeec8..ff9e7cc97c65 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -281,6 +281,18 @@ 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.
+nocompress_extension=%s Support adding specified extension, so that f2fs can disable
+ compression on those corresponding files, just contrary to compression extension.
+ If you know exactly which files cannot be compressed, you can use this.
+ The same extension name can't appear in both compress and nocompress
+ extension at the same time.
+ If the compress extension specifies all files, the types specified by the
+ nocompress extension will be treated as special cases and will not be compressed.
+ Don't allow use '*' to specifie all file in nocompress extension.
+ After add nocompress_extension, the priority should be:
+ dir_flag < comp_extention,nocompress_extension < comp_file_flag,no_comp_file_flag.
+ See more in compression sections.
+
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
@@ -289,6 +301,9 @@ compress_mode=%s Control file compression mode. This supports "fs" and "user"
choosing the target file and the timing. The user can do manual
compression/decompression on the compression enabled files using
ioctls.
+compress_cache Support to use address space of a filesystem managed inode to
+ cache compressed block, in order to improve cache hit ratio of
+ random read.
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
@@ -717,10 +732,10 @@ users.
===================== ======================== ===================
User F2FS Block
===================== ======================== ===================
- META WRITE_LIFE_NOT_SET
- HOT_NODE "
- WARM_NODE "
- COLD_NODE "
+N/A META WRITE_LIFE_NOT_SET
+N/A HOT_NODE "
+N/A WARM_NODE "
+N/A COLD_NODE "
ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
extension list " "
@@ -746,10 +761,10 @@ WRITE_LIFE_LONG " WRITE_LIFE_LONG
===================== ======================== ===================
User F2FS Block
===================== ======================== ===================
- META WRITE_LIFE_MEDIUM;
- HOT_NODE WRITE_LIFE_NOT_SET
- WARM_NODE "
- COLD_NODE WRITE_LIFE_NONE
+N/A META WRITE_LIFE_MEDIUM;
+N/A HOT_NODE WRITE_LIFE_NOT_SET
+N/A WARM_NODE "
+N/A COLD_NODE WRITE_LIFE_NONE
ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
extension list " "
@@ -814,13 +829,30 @@ Compression implementation
all logical blocks in cluster contain valid data and compress ratio of
cluster data is lower than specified threshold.
-- To enable compression on regular inode, there are three ways:
+- To enable compression on regular inode, there are four ways:
* 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
+- To disable compression on regular inode, there are two ways:
+
+ * chattr -c file
+ * mount w/ -o nocompress_extension=ext; touch file.ext
+
+- Priority in between FS_COMPR_FL, FS_NOCOMP_FS, extensions:
+
+ * compress_extension=so; nocompress_extension=zip; chattr +c dir; touch
+ dir/foo.so; touch dir/bar.zip; touch dir/baz.txt; then foo.so and baz.txt
+ should be compresse, bar.zip should be non-compressed. chattr +c dir/bar.zip
+ can enable compress on bar.zip.
+ * compress_extension=so; nocompress_extension=zip; chattr -c dir; touch
+ dir/foo.so; touch dir/bar.zip; touch dir/baz.txt; then foo.so should be
+ compresse, bar.zip and baz.txt should be non-compressed.
+ chattr+c dir/bar.zip; chattr+c dir/baz.txt; can enable compress on bar.zip
+ and baz.txt.
+
- 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