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-rw-r--r--Documentation/ABI/testing/sysfs-fs-f2fs31
-rw-r--r--Documentation/filesystems/f2fs.rst14
2 files changed, 44 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index cbeac1bebe2f..4849b8e84e42 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -276,7 +276,7 @@ Date April 2019
Contact: "Daniel Rosenberg" <drosen@google.com>
Description: If checkpoint=disable, it displays the number of blocks that
are unusable.
- If checkpoint=enable it displays the enumber of blocks that
+ If checkpoint=enable it displays the number of blocks that
would be unusable if checkpoint=disable were to be set.
What: /sys/fs/f2fs/<disk>/encoding
@@ -409,3 +409,32 @@ Description: Give a way to change checkpoint merge daemon's io priority.
I/O priority "3". We can select the class between "rt" and "be",
and set the I/O priority within valid range of it. "," delimiter
is necessary in between I/O class and priority number.
+
+What: /sys/fs/f2fs/<disk>/ovp_segments
+Date: March 2021
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Shows the number of overprovision segments.
+
+What: /sys/fs/f2fs/<disk>/compr_written_block
+Date: March 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the block count written after compression since mount. Note
+ that when the compressed blocks are deleted, this count doesn't
+ decrease. If you write "0" here, you can initialize
+ compr_written_block and compr_saved_block to "0".
+
+What: /sys/fs/f2fs/<disk>/compr_saved_block
+Date: March 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the saved block count with compression since mount. Note
+ that when the compressed blocks are deleted, this count doesn't
+ decrease. If you write "0" here, you can initialize
+ compr_written_block and compr_saved_block to "0".
+
+What: /sys/fs/f2fs/<disk>/compr_new_inode
+Date: March 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the count of inode newly enabled for compression since mount.
+ Note that when the compression is disabled for the files, this count
+ doesn't decrease. If you write "0" here, you can initialize
+ compr_new_inode to "0".
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 35ed01a5fbc9..992bf91eeec8 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -110,6 +110,12 @@ background_gc=%s Turn on/off cleaning operations, namely garbage
on synchronous garbage collection running in background.
Default value for this option is on. So garbage
collection is on by default.
+gc_merge When background_gc is on, this option can be enabled to
+ let background GC thread to handle foreground GC requests,
+ it can eliminate the sluggish issue caused by slow foreground
+ GC operation when GC is triggered from a process with limited
+ I/O and CPU resources.
+nogc_merge Disable GC merge feature.
disable_roll_forward Disable the roll-forward recovery routine
norecovery Disable the roll-forward recovery routine, mounted read-
only (i.e., -o ro,disable_roll_forward)
@@ -813,6 +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::