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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/ABI/testing/sysfs-fs-f2fs
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
+Date: July 2013
+Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
+Description: Controls the maximum sleep time for gc_thread. Time
+ is in milliseconds.
+
+What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
+Date: July 2013
+Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
+Description: Controls the minimum sleep time for gc_thread. Time
+ is in milliseconds.
+
+What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
+Date: July 2013
+Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
+Description: Controls the default sleep time for gc_thread. Time
+ is in milliseconds.
+
+What: /sys/fs/f2fs/<disk>/gc_idle
+Date: July 2013
+Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
+Description: Controls the victim selection policy for garbage collection.
+ Setting gc_idle = 0(default) will disable this option. Setting:
+
+ =========== ===============================================
+ gc_idle = 1 will select the Cost Benefit approach & setting
+ gc_idle = 2 will select the greedy approach & setting
+ gc_idle = 3 will select the age-threshold based approach.
+ =========== ===============================================
+
+What: /sys/fs/f2fs/<disk>/reclaim_segments
+Date: October 2013
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: This parameter controls the number of prefree segments to be
+ reclaimed. If the number of prefree segments is larger than
+ the number of segments in the proportion to the percentage
+ over total volume size, f2fs tries to conduct checkpoint to
+ reclaim the prefree segments to free segments.
+ By default, 5% over total # of segments.
+
+What: /sys/fs/f2fs/<disk>/main_blkaddr
+Date: November 2019
+Contact: "Ramon Pantin" <pantin@google.com>
+Description: Shows first block address of MAIN area.
+
+What: /sys/fs/f2fs/<disk>/ipu_policy
+Date: November 2013
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the in-place-update policy.
+ updates in f2fs. User can set:
+
+ ==== =================
+ 0x01 F2FS_IPU_FORCE
+ 0x02 F2FS_IPU_SSR
+ 0x04 F2FS_IPU_UTIL
+ 0x08 F2FS_IPU_SSR_UTIL
+ 0x10 F2FS_IPU_FSYNC
+ 0x20 F2FS_IPU_ASYNC
+ 0x40 F2FS_IPU_NOCACHE
+ 0x80 F2FS_IPU_HONOR_OPU_WRITE
+ ==== =================
+
+ Refer segment.h for details.
+
+What: /sys/fs/f2fs/<disk>/min_ipu_util
+Date: November 2013
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the FS utilization condition for the in-place-update
+ policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
+
+What: /sys/fs/f2fs/<disk>/min_fsync_blocks
+Date: September 2014
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the dirty page count condition for the in-place-update
+ policies.
+
+What: /sys/fs/f2fs/<disk>/min_seq_blocks
+Date: August 2018
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the dirty page count condition for batched sequential
+ writes in writepages.
+
+What: /sys/fs/f2fs/<disk>/min_hot_blocks
+Date: March 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the dirty page count condition for redefining hot data.
+
+What: /sys/fs/f2fs/<disk>/min_ssr_sections
+Date: October 2017
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Controls the free section threshold to trigger SSR allocation.
+ If this is large, SSR mode will be enabled early.
+
+What: /sys/fs/f2fs/<disk>/max_small_discards
+Date: November 2013
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the issue rate of discard commands that consist of small
+ blocks less than 2MB. The candidates to be discarded are cached until
+ checkpoint is triggered, and issued during the checkpoint.
+ By default, it is disabled with 0.
+
+What: /sys/fs/f2fs/<disk>/max_discard_request
+Date: December 2021
+Contact: "Konstantin Vyshetsky" <vkon@google.com>
+Description: Controls the number of discards a thread will issue at a time.
+ Higher number will allow the discard thread to finish its work
+ faster, at the cost of higher latency for incomming I/O.
+
+What: /sys/fs/f2fs/<disk>/min_discard_issue_time
+Date: December 2021
+Contact: "Konstantin Vyshetsky" <vkon@google.com>
+Description: Controls the interval the discard thread will wait between
+ issuing discard requests when there are discards to be issued and
+ no I/O aware interruptions occur.
+
+What: /sys/fs/f2fs/<disk>/mid_discard_issue_time
+Date: December 2021
+Contact: "Konstantin Vyshetsky" <vkon@google.com>
+Description: Controls the interval the discard thread will wait between
+ issuing discard requests when there are discards to be issued and
+ an I/O aware interruption occurs.
+
+What: /sys/fs/f2fs/<disk>/max_discard_issue_time
+Date: December 2021
+Contact: "Konstantin Vyshetsky" <vkon@google.com>
+Description: Controls the interval the discard thread will wait when there are
+ no discard operations to be issued.
+
+What: /sys/fs/f2fs/<disk>/discard_granularity
+Date: July 2017
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Controls discard granularity of inner discard thread. Inner thread
+ will not issue discards with size that is smaller than granularity.
+ The unit size is one block(4KB), now only support configuring
+ in range of [1, 512]. Default value is 4(=16KB).
+
+What: /sys/fs/f2fs/<disk>/umount_discard_timeout
+Date: January 2019
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Set timeout to issue discard commands during umount.
+ Default: 5 secs
+
+What: /sys/fs/f2fs/<disk>/pending_discard
+Date: November 2021
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Shows the number of pending discard commands in the queue.
+
+What: /sys/fs/f2fs/<disk>/max_victim_search
+Date: January 2014
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the number of trials to find a victim segment
+ when conducting SSR and cleaning operations. The default value
+ is 4096 which covers 8GB block address range.
+
+What: /sys/fs/f2fs/<disk>/migration_granularity
+Date: October 2018
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Controls migration granularity of garbage collection on large
+ section, it can let GC move partial segment{s} of one section
+ in one GC cycle, so that dispersing heavy overhead GC to
+ multiple lightweight one.
+
+What: /sys/fs/f2fs/<disk>/dir_level
+Date: March 2014
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the directory level for large directory. If a
+ directory has a number of files, it can reduce the file lookup
+ latency by increasing this dir_level value. Otherwise, it
+ needs to decrease this value to reduce the space overhead.
+ The default value is 0.
+
+What: /sys/fs/f2fs/<disk>/ram_thresh
+Date: March 2014
+Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description: Controls the memory footprint used by free nids and cached
+ nat entries. By default, 1 is set, which indicates
+ 10 MB / 1 GB RAM.
+
+What: /sys/fs/f2fs/<disk>/batched_trim_sections
+Date: February 2015
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the trimming rate in batch mode.
+ <deprecated>
+
+What: /sys/fs/f2fs/<disk>/cp_interval
+Date: October 2015
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the checkpoint timing, set to 60 seconds by default.
+
+What: /sys/fs/f2fs/<disk>/idle_interval
+Date: January 2016
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls the idle timing of system, if there is no FS operation
+ during given interval.
+ Set to 5 seconds by default.
+
+What: /sys/fs/f2fs/<disk>/discard_idle_interval
+Date: September 2018
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Contact: "Sahitya Tummala" <stummala@codeaurora.org>
+Description: Controls the idle timing of discard thread given
+ this time interval.
+ Default is 5 secs.
+
+What: /sys/fs/f2fs/<disk>/gc_idle_interval
+Date: September 2018
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Contact: "Sahitya Tummala" <stummala@codeaurora.org>
+Description: Controls the idle timing for gc path. Set to 5 seconds by default.
+
+What: /sys/fs/f2fs/<disk>/iostat_enable
+Date: August 2017
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Controls to enable/disable IO stat.
+
+What: /sys/fs/f2fs/<disk>/ra_nid_pages
+Date: October 2015
+Contact: "Chao Yu" <chao2.yu@samsung.com>
+Description: Controls the count of nid pages to be readaheaded.
+ When building free nids, F2FS reads NAT blocks ahead for
+ speed up. Default is 0.
+
+What: /sys/fs/f2fs/<disk>/dirty_nats_ratio
+Date: January 2016
+Contact: "Chao Yu" <chao2.yu@samsung.com>
+Description: Controls dirty nat entries ratio threshold, if current
+ ratio exceeds configured threshold, checkpoint will
+ be triggered for flushing dirty nat entries.
+
+What: /sys/fs/f2fs/<disk>/lifetime_write_kbytes
+Date: January 2016
+Contact: "Shuoran Liu" <liushuoran@huawei.com>
+Description: Shows total written kbytes issued to disk.
+
+What: /sys/fs/f2fs/<disk>/features
+Date: July 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/
+ Shows all enabled features in current device.
+ Supported features:
+ encryption, blkzoned, extra_attr, projquota, inode_checksum,
+ flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
+ verity, sb_checksum, casefold, readonly, compression, pin_file.
+
+What: /sys/fs/f2fs/<disk>/feature_list/
+Date: June 2021
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule.
+ Supported on-disk features:
+ encryption, block_zoned (aka blkzoned), extra_attr,
+ project_quota (aka projquota), inode_checksum,
+ flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
+ verity, sb_checksum, casefold, readonly, compression.
+ Note that, pin_file is moved into /sys/fs/f2fs/features/.
+
+What: /sys/fs/f2fs/features/
+Date: July 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Shows all enabled kernel features.
+ Supported features:
+ encryption, block_zoned, extra_attr, project_quota,
+ inode_checksum, flexible_inline_xattr, quota_ino,
+ inode_crtime, lost_found, verity, sb_checksum,
+ casefold, readonly, compression, test_dummy_encryption_v2,
+ atomic_write, pin_file, encrypted_casefold.
+
+What: /sys/fs/f2fs/<disk>/inject_rate
+Date: May 2016
+Contact: "Sheng Yong" <shengyong1@huawei.com>
+Description: Controls the injection rate of arbitrary faults.
+
+What: /sys/fs/f2fs/<disk>/inject_type
+Date: May 2016
+Contact: "Sheng Yong" <shengyong1@huawei.com>
+Description: Controls the injection type of arbitrary faults.
+
+What: /sys/fs/f2fs/<disk>/dirty_segments
+Date: October 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Shows the number of dirty segments.
+
+What: /sys/fs/f2fs/<disk>/reserved_blocks
+Date: June 2017
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Controls target reserved blocks in system, the threshold
+ is soft, it could exceed current available user space.
+
+What: /sys/fs/f2fs/<disk>/current_reserved_blocks
+Date: October 2017
+Contact: "Yunlong Song" <yunlong.song@huawei.com>
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Shows current reserved blocks in system, it may be temporarily
+ smaller than target_reserved_blocks, but will gradually
+ increase to target_reserved_blocks when more free blocks are
+ freed by user later.
+
+What: /sys/fs/f2fs/<disk>/gc_urgent
+Date: August 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Do background GC aggressively when set. Set to 0 by default.
+ gc urgent high(1): does GC forcibly in a period of given
+ gc_urgent_sleep_time and ignores I/O idling check. uses greedy
+ GC approach and turns SSR mode on.
+ gc urgent low(2): lowers the bar of checking I/O idling in
+ order to process outstanding discard commands and GC a
+ little bit aggressively. uses cost benefit GC approach.
+ gc urgent mid(3): does GC forcibly in a period of given
+ gc_urgent_sleep_time and executes a mid level of I/O idling check.
+ uses cost benefit GC approach.
+
+What: /sys/fs/f2fs/<disk>/gc_urgent_sleep_time
+Date: August 2017
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls sleep time of GC urgent mode. Set to 500ms by default.
+
+What: /sys/fs/f2fs/<disk>/readdir_ra
+Date: November 2017
+Contact: "Sheng Yong" <shengyong1@huawei.com>
+Description: Controls readahead inode block in readdir. Enabled by default.
+
+What: /sys/fs/f2fs/<disk>/gc_pin_file_thresh
+Date: January 2018
+Contact: Jaegeuk Kim <jaegeuk@kernel.org>
+Description: This indicates how many GC can be failed for the pinned
+ file. If it exceeds this, F2FS doesn't guarantee its pinning
+ state. 2048 trials is set by default.
+
+What: /sys/fs/f2fs/<disk>/extension_list
+Date: Feburary 2018
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Used to control configure extension list:
+ - Query: cat /sys/fs/f2fs/<disk>/extension_list
+ - Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
+ - Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
+ - [h] means add/del hot file extension
+ - [c] means add/del cold file extension
+
+What: /sys/fs/f2fs/<disk>/unusable
+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 number of blocks that
+ would be unusable if checkpoint=disable were to be set.
+
+What: /sys/fs/f2fs/<disk>/encoding
+Date July 2019
+Contact: "Daniel Rosenberg" <drosen@google.com>
+Description: Displays name and version of the encoding set for the filesystem.
+ If no encoding is set, displays (none)
+
+What: /sys/fs/f2fs/<disk>/free_segments
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of free segments in disk.
+
+What: /sys/fs/f2fs/<disk>/cp_foreground_calls
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of checkpoint operations performed on demand. Available when
+ CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/cp_background_calls
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of checkpoint operations performed in the background to
+ free segments. Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/gc_foreground_calls
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of garbage collection operations performed on demand.
+ Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/gc_background_calls
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of garbage collection operations triggered in background.
+ Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/moved_blocks_foreground
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of blocks moved by garbage collection in foreground.
+ Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/moved_blocks_background
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Number of blocks moved by garbage collection in background.
+ Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/avg_vblocks
+Date: September 2019
+Contact: "Hridya Valsaraju" <hridya@google.com>
+Description: Average number of valid blocks.
+ Available when CONFIG_F2FS_STAT_FS=y.
+
+What: /sys/fs/f2fs/<disk>/mounted_time_sec
+Date: February 2020
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Show the mounted time in secs of this partition.
+
+What: /sys/fs/f2fs/<disk>/data_io_flag
+Date: April 2020
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Give a way to attach REQ_META|FUA to data writes
+ given temperature-based bits. Now the bits indicate:
+
+ +-------------------+-------------------+
+ | REQ_META | REQ_FUA |
+ +------+------+-----+------+------+-----+
+ | 5 | 4 | 3 | 2 | 1 | 0 |
+ +------+------+-----+------+------+-----+
+ | Cold | Warm | Hot | Cold | Warm | Hot |
+ +------+------+-----+------+------+-----+
+
+What: /sys/fs/f2fs/<disk>/node_io_flag
+Date: June 2020
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Give a way to attach REQ_META|FUA to node writes
+ given temperature-based bits. Now the bits indicate:
+
+ +-------------------+-------------------+
+ | REQ_META | REQ_FUA |
+ +------+------+-----+------+------+-----+
+ | 5 | 4 | 3 | 2 | 1 | 0 |
+ +------+------+-----+------+------+-----+
+ | Cold | Warm | Hot | Cold | Warm | Hot |
+ +------+------+-----+------+------+-----+
+
+What: /sys/fs/f2fs/<disk>/iostat_period_ms
+Date: April 2020
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Give a way to change iostat_period time. 3secs by default.
+ The new iostat trace gives stats gap given the period.
+What: /sys/fs/f2fs/<disk>/max_io_bytes
+Date: December 2020
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: This gives a control to limit the bio size in f2fs.
+ Default is zero, which will follow underlying block layer limit,
+ whereas, if it has a certain bytes value, f2fs won't submit a
+ bio larger than that size.
+
+What: /sys/fs/f2fs/<disk>/stat/sb_status
+Date: December 2020
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: Show status of f2fs superblock in real time.
+
+ ====== ===================== =================================
+ value sb status macro description
+ 0x1 SBI_IS_DIRTY dirty flag for checkpoint
+ 0x2 SBI_IS_CLOSE specify unmounting
+ 0x4 SBI_NEED_FSCK need fsck.f2fs to fix
+ 0x8 SBI_POR_DOING recovery is doing or not
+ 0x10 SBI_NEED_SB_WRITE need to recover superblock
+ 0x20 SBI_NEED_CP need to checkpoint
+ 0x40 SBI_IS_SHUTDOWN shutdown by ioctl
+ 0x80 SBI_IS_RECOVERED recovered orphan/data
+ 0x100 SBI_CP_DISABLED CP was disabled last mount
+ 0x200 SBI_CP_DISABLED_QUICK CP was disabled quickly
+ 0x400 SBI_QUOTA_NEED_FLUSH need to flush quota info in CP
+ 0x800 SBI_QUOTA_SKIP_FLUSH skip flushing quota in current CP
+ 0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted
+ 0x2000 SBI_IS_RESIZEFS resizefs is in process
+ 0x4000 SBI_IS_FREEZING freefs is in process
+ ====== ===================== =================================
+
+What: /sys/fs/f2fs/<disk>/stat/cp_status
+Date: September 2022
+Contact: "Chao Yu" <chao.yu@oppo.com>
+Description: Show status of f2fs checkpoint in real time.
+
+ =============================== ==============================
+ cp flag value
+ CP_UMOUNT_FLAG 0x00000001
+ CP_ORPHAN_PRESENT_FLAG 0x00000002
+ CP_COMPACT_SUM_FLAG 0x00000004
+ CP_ERROR_FLAG 0x00000008
+ CP_FSCK_FLAG 0x00000010
+ CP_FASTBOOT_FLAG 0x00000020
+ CP_CRC_RECOVERY_FLAG 0x00000040
+ CP_NAT_BITS_FLAG 0x00000080
+ CP_TRIMMED_FLAG 0x00000100
+ CP_NOCRC_RECOVERY_FLAG 0x00000200
+ CP_LARGE_NAT_BITMAP_FLAG 0x00000400
+ CP_QUOTA_NEED_FSCK_FLAG 0x00000800
+ CP_DISABLED_FLAG 0x00001000
+ CP_DISABLED_QUICK_FLAG 0x00002000
+ CP_RESIZEFS_FLAG 0x00004000
+ =============================== ==============================
+
+What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
+Date: January 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Give a way to change checkpoint merge daemon's io priority.
+ Its default value is "be,3", which means "BE" I/O class and
+ 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".
+
+What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio
+Date: May 2021
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: When ATGC is on, it controls candidate ratio in order to limit total
+ number of potential victim in all candidates, the value should be in
+ range of [0, 100], by default it was initialized as 20(%).
+
+What: /sys/fs/f2fs/<disk>/atgc_candidate_count
+Date: May 2021
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: When ATGC is on, it controls candidate count in order to limit total
+ number of potential victim in all candidates, by default it was
+ initialized as 10 (sections).
+
+What: /sys/fs/f2fs/<disk>/atgc_age_weight
+Date: May 2021
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: When ATGC is on, it controls age weight to balance weight proportion
+ in between aging and valid blocks, the value should be in range of
+ [0, 100], by default it was initialized as 60(%).
+
+What: /sys/fs/f2fs/<disk>/atgc_age_threshold
+Date: May 2021
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description: When ATGC is on, it controls age threshold to bypass GCing young
+ candidates whose age is not beyond the threshold, by default it was
+ initialized as 604800 seconds (equals to 7 days).
+
+What: /sys/fs/f2fs/<disk>/gc_reclaimed_segments
+Date: July 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show how many segments have been reclaimed by GC during a specific
+ GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,
+ 3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid)
+ You can re-initialize this value to "0".
+
+What: /sys/fs/f2fs/<disk>/gc_segment_mode
+Date: July 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: You can control for which gc mode the "gc_reclaimed_segments" node shows.
+ Refer to the description of the modes in "gc_reclaimed_segments".
+
+What: /sys/fs/f2fs/<disk>/seq_file_ra_mul
+Date: July 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: You can control the multiplier value of bdi device readahead window size
+ between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option.
+
+What: /sys/fs/f2fs/<disk>/max_fragment_chunk
+Date: August 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: With "mode=fragment:block" mount options, we can scatter block allocation.
+ f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
+ in the length of 1..<max_fragment_hole> by turns. This value can be set
+ between 1..512 and the default value is 4.
+
+What: /sys/fs/f2fs/<disk>/max_fragment_hole
+Date: August 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: With "mode=fragment:block" mount options, we can scatter block allocation.
+ f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
+ in the length of 1..<max_fragment_hole> by turns. This value can be set
+ between 1..512 and the default value is 4.
+
+What: /sys/fs/f2fs/<disk>/gc_urgent_high_remaining
+Date: December 2021
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: You can set the trial count limit for GC urgent high mode with this value.
+ If GC thread gets to the limit, the mode will turn back to GC normal mode.
+ By default, the value is zero, which means there is no limit like before.
+
+What: /sys/fs/f2fs/<disk>/max_roll_forward_node_blocks
+Date: January 2022
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Controls max # of node block writes to be used for roll forward
+ recovery. This can limit the roll forward recovery time.
+
+What: /sys/fs/f2fs/<disk>/unusable_blocks_per_sec
+Date: June 2022
+Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description: Shows the number of unusable blocks in a section which was defined by
+ the zone capacity reported by underlying zoned device.
+
+What: /sys/fs/f2fs/<disk>/current_atomic_write
+Date: July 2022
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the total current atomic write block count, which is not committed yet.
+ This is a read-only entry.
+
+What: /sys/fs/f2fs/<disk>/peak_atomic_write
+Date: July 2022
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the peak value of total current atomic write block count after boot.
+ If you write "0" here, you can initialize to "0".
+
+What: /sys/fs/f2fs/<disk>/committed_atomic_block
+Date: July 2022
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the accumulated total committed atomic write block count after boot.
+ If you write "0" here, you can initialize to "0".
+
+What: /sys/fs/f2fs/<disk>/revoked_atomic_block
+Date: July 2022
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Show the accumulated total revoked atomic write block count after boot.
+ If you write "0" here, you can initialize to "0".