summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-05-04 18:03:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-04 18:03:38 -0700
commitd0195c7d7af6a456c37f4b4b2df5528f10714482 (patch)
tree9b93122a6011814b63fd5a66d2a0a240388ad5e5 /Documentation
parente4adffb8daf476a01e7b4a55f586dc8c26e81392 (diff)
parent9557727876674893d35940fddbd03d3b505e7ed8 (diff)
downloadlinux-d0195c7d7af6a456c37f4b4b2df5528f10714482.tar.bz2
Merge tag 'f2fs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim: "In this round, we added a new mount option, "checkpoint_merge", which introduces a kernel thread dealing with the f2fs checkpoints. Once we start to manage the IO priority along with blk-cgroup, the checkpoint operation can be processed in a lower priority under the process context. Since the checkpoint holds all the filesystem operations, we give a higher priority to the checkpoint thread all the time. Enhancements: - introduce gc_merge mount option to introduce a checkpoint thread - improve to run discard thread efficiently - allow modular compression algorithms - expose # of overprivision segments to sysfs - expose runtime compression stat to sysfs Bug fixes: - fix OOB memory access by the node id lookup - avoid touching checkpointed data in the checkpoint-disabled mode - fix the resizing flow to avoid kernel panic and race conditions - fix block allocation issues on pinned files - address some swapfile issues - fix hugtask problem and kernel panic during atomic write operations - don't start checkpoint thread in RO And, we've cleaned up some kernel coding style and build warnings. In addition, we fixed some minor race conditions and error handling routines" * tag 'f2fs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (48 commits) f2fs: drop inplace IO if fs status is abnormal f2fs: compress: remove unneed check condition f2fs: clean up left deprecated IO trace codes f2fs: avoid using native allocate_segment_by_default() f2fs: remove unnecessary struct declaration f2fs: fix to avoid NULL pointer dereference f2fs: avoid duplicated codes for cleanup f2fs: document: add description about compressed space handling f2fs: clean up build warnings f2fs: fix the periodic wakeups of discard thread f2fs: fix to avoid accessing invalid fio in f2fs_allocate_data_block() f2fs: fix to avoid GC/mmap race with f2fs_truncate() f2fs: set checkpoint_merge by default f2fs: Fix a hungtask problem in atomic write f2fs: fix to restrict mount condition on readonly block device f2fs: introduce gc_merge mount option f2fs: fix to cover __allocate_new_section() with curseg_lock f2fs: fix wrong alloc_type in f2fs_do_replace_block f2fs: delete empty compress.h f2fs: fix a typo in inode.c ...
Diffstat (limited to 'Documentation')
-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::