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-rw-r--r--Documentation/ABI/testing/sysfs-fs-f2fs482
1 files changed, 449 insertions, 33 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 4bb93a06d8ab..1a4d83953379 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -20,9 +20,13 @@ 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 = 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
@@ -37,18 +41,32 @@ Description: This parameter controls the number of prefree segments to be
What: /sys/fs/f2fs/<disk>/main_blkaddr
Date: November 2019
Contact: "Ramon Pantin" <pantin@google.com>
-Description:
- Shows first block address of MAIN area.
+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.
+
+ ===== =============== ===================================================
+ value policy description
+ 0x00 DISABLE disable IPU(=default option in LFS mode)
+ 0x01 FORCE all the time
+ 0x02 SSR if SSR mode is activated
+ 0x04 UTIL if FS utilization is over threshold
+ 0x08 SSR_UTIL if SSR mode is activated and FS utilization is over
+ threshold
+ 0x10 FSYNC activated in fsync path only for high performance
+ flash storages. IPU will be triggered only if the
+ # of dirty pages over min_fsync_blocks.
+ (=default option)
+ 0x20 ASYNC do IPU given by asynchronous write requests
+ 0x40 NOCACHE disable IPU bio cache
+ 0x80 HONOR_OPU_WRITE use OPU write prior to IPU write if inode has
+ FI_OPU_WRITE flag
+ ===== =============== ===================================================
+
Refer segment.h for details.
What: /sys/fs/f2fs/<disk>/min_ipu_util
@@ -84,9 +102,42 @@ 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.
+ blocks less than 2MB. The candidates to be discarded are cached during
+ checkpoint, and issued by issue_discard thread after checkpoint.
+ It is enabled by default.
+
+What: /sys/fs/f2fs/<disk>/max_ordered_discard
+Date: October 2022
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: Controls the maximum ordered discard, the unit size is one block(4KB).
+ Set it to 16 by default.
+
+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 incoming 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
@@ -94,7 +145,8 @@ 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).
+ in range of [1, 512]. Default value is 16.
+ For small devices, default value is 1.
What: /sys/fs/f2fs/<disk>/umount_discard_timeout
Date: January 2019
@@ -102,6 +154,11 @@ 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>
@@ -133,12 +190,6 @@ 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>
@@ -154,7 +205,7 @@ Description: Controls the idle timing of system, if there is no FS operation
What: /sys/fs/f2fs/<disk>/discard_idle_interval
Date: September 2018
Contact: "Chao Yu" <yuchao0@huawei.com>
-Contact: "Sahitya Tummala" <stummala@codeaurora.org>
+Contact: "Sahitya Tummala" <quic_stummala@quicinc.com>
Description: Controls the idle timing of discard thread given
this time interval.
Default is 5 secs.
@@ -162,7 +213,7 @@ Description: Controls the idle timing of discard thread given
What: /sys/fs/f2fs/<disk>/gc_idle_interval
Date: September 2018
Contact: "Chao Yu" <yuchao0@huawei.com>
-Contact: "Sahitya Tummala" <stummala@codeaurora.org>
+Contact: "Sahitya Tummala" <quic_stummala@quicinc.com>
Description: Controls the idle timing for gc path. Set to 5 seconds by default.
What: /sys/fs/f2fs/<disk>/iostat_enable
@@ -192,7 +243,34 @@ Description: Shows total written kbytes issued to disk.
What: /sys/fs/f2fs/<disk>/features
Date: July 2017
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description: Shows all enabled features in current device.
+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
@@ -227,9 +305,16 @@ Description: Shows current reserved blocks in system, it may be temporarily
What: /sys/fs/f2fs/<disk>/gc_urgent
Date: August 2017
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description: Do background GC agressively when set. When gc_urgent = 1,
- background thread starts to do GC by given gc_urgent_sleep_time
- interval. It is set to 0 by default.
+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
@@ -249,7 +334,7 @@ Description: This indicates how many GC can be failed for the pinned
state. 2048 trials is set by default.
What: /sys/fs/f2fs/<disk>/extension_list
-Date: Feburary 2018
+Date: February 2018
Contact: "Chao Yu" <yuchao0@huawei.com>
Description: Used to control configure extension list:
- Query: cat /sys/fs/f2fs/<disk>/extension_list
@@ -263,7 +348,7 @@ 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
@@ -329,21 +414,352 @@ 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 |
+
+ +-------------------+-------------------+
+ | 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 |
+
+ +-------------------+-------------------+
+ | 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>/stat/issued_discard
+Date: December 2023
+Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
+Description: Shows the number of issued discard.
+
+What: /sys/fs/f2fs/<disk>/stat/queued_discard
+Date: December 2023
+Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
+Description: Shows the number of queued discard.
+
+What: /sys/fs/f2fs/<disk>/stat/undiscard_blks
+Date: December 2023
+Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
+Description: Shows the total number of undiscard blocks.
+
+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_remaining_trials
+Date: October 2022
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: You can set the trial count limit for GC urgent and idle 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".
+
+What: /sys/fs/f2fs/<disk>/gc_mode
+Date: October 2022
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: Show the current gc_mode as a string.
+ This is a read-only entry.
+
+What: /sys/fs/f2fs/<disk>/discard_urgent_util
+Date: November 2022
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: When space utilization exceeds this, do background DISCARD aggressively.
+ Does DISCARD forcibly in a period of given min_discard_issue_time when the number
+ of discards is not 0 and set discard granularity to 1.
+ Default: 80
+
+What: /sys/fs/f2fs/<disk>/hot_data_age_threshold
+Date: November 2022
+Contact: "Ping Xiong" <xiongping1@xiaomi.com>
+Description: When DATA SEPARATION is on, it controls the age threshold to indicate
+ the data blocks as hot. By default it was initialized as 262144 blocks
+ (equals to 1GB).
+
+What: /sys/fs/f2fs/<disk>/warm_data_age_threshold
+Date: November 2022
+Contact: "Ping Xiong" <xiongping1@xiaomi.com>
+Description: When DATA SEPARATION is on, it controls the age threshold to indicate
+ the data blocks as warm. By default it was initialized as 2621440 blocks
+ (equals to 10GB).
+
+What: /sys/fs/f2fs/<disk>/fault_rate
+Date: May 2016
+Contact: "Sheng Yong" <shengyong@oppo.com>
+Contact: "Chao Yu" <chao@kernel.org>
+Description: Enable fault injection in all supported types with
+ specified injection rate.
+
+What: /sys/fs/f2fs/<disk>/fault_type
+Date: May 2016
+Contact: "Sheng Yong" <shengyong@oppo.com>
+Contact: "Chao Yu" <chao@kernel.org>
+Description: Support configuring fault injection type, should be
+ enabled with fault_injection option, fault type value
+ is shown below, it supports single or combined type.
+
+ =========================== ===========
+ Type_Name Type_Value
+ =========================== ===========
+ FAULT_KMALLOC 0x000000001
+ FAULT_KVMALLOC 0x000000002
+ FAULT_PAGE_ALLOC 0x000000004
+ FAULT_PAGE_GET 0x000000008
+ FAULT_ALLOC_BIO 0x000000010 (obsolete)
+ FAULT_ALLOC_NID 0x000000020
+ FAULT_ORPHAN 0x000000040
+ FAULT_BLOCK 0x000000080
+ FAULT_DIR_DEPTH 0x000000100
+ FAULT_EVICT_INODE 0x000000200
+ FAULT_TRUNCATE 0x000000400
+ FAULT_READ_IO 0x000000800
+ FAULT_CHECKPOINT 0x000001000
+ FAULT_DISCARD 0x000002000
+ FAULT_WRITE_IO 0x000004000
+ FAULT_SLAB_ALLOC 0x000008000
+ FAULT_DQUOT_INIT 0x000010000
+ FAULT_LOCK_OP 0x000020000
+ FAULT_BLKADDR_VALIDITY 0x000040000
+ FAULT_BLKADDR_CONSISTENCE 0x000080000
+ FAULT_NO_SEGMENT 0x000100000
+ =========================== ===========
+
+What: /sys/fs/f2fs/<disk>/discard_io_aware_gran
+Date: January 2023
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: Controls background discard granularity of inner discard thread
+ when is not in idle. 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 [0, 512].
+ Default: 512
+
+What: /sys/fs/f2fs/<disk>/last_age_weight
+Date: January 2023
+Contact: "Ping Xiong" <xiongping1@xiaomi.com>
+Description: When DATA SEPARATION is on, it controls the weight of last data block age.
+
+What: /sys/fs/f2fs/<disk>/compress_watermark
+Date: February 2023
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: When compress cache is on, it controls free memory watermark
+ in order to limit caching compress page. If free memory is lower
+ than watermark, then deny caching compress page. The value should be in
+ range of (0, 100], by default it was initialized as 20(%).
+
+What: /sys/fs/f2fs/<disk>/compress_percent
+Date: February 2023
+Contact: "Yangtao Li" <frank.li@vivo.com>
+Description: When compress cache is on, it controls cached page
+ percent(compress pages / free_ram) in order to limit caching compress page.
+ If cached page percent exceed threshold, then deny caching compress page.
+ The value should be in range of (0, 100], by default it was initialized
+ as 20(%).
+
+What: /sys/fs/f2fs/<disk>/discard_io_aware
+Date: November 2023
+Contact: "Chao Yu" <chao@kernel.org>
+Description: It controls to enable/disable IO aware feature for background discard.
+ By default, the value is 1 which indicates IO aware is on.