1What:		/sys/fs/f2fs/<disk>/gc_max_sleep_time
2Date:		July 2013
3Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
4Description:	Controls the maximum sleep time for gc_thread. Time
5		is in milliseconds.
6
7What:		/sys/fs/f2fs/<disk>/gc_min_sleep_time
8Date:		July 2013
9Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
10Description:	Controls the minimum sleep time for gc_thread. Time
11		is in milliseconds.
12
13What:		/sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
14Date:		July 2013
15Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
16Description:	Controls the default sleep time for gc_thread. Time
17		is in milliseconds.
18
19What:		/sys/fs/f2fs/<disk>/gc_idle
20Date:		July 2013
21Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
22Description:	Controls the victim selection policy for garbage collection.
23		Setting gc_idle = 0(default) will disable this option. Setting:
24
25		===========  ===============================================
26		gc_idle = 1  will select the Cost Benefit approach & setting
27		gc_idle = 2  will select the greedy approach & setting
28		gc_idle = 3  will select the age-threshold based approach.
29		===========  ===============================================
30
31What:		/sys/fs/f2fs/<disk>/reclaim_segments
32Date:		October 2013
33Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
34Description:	This parameter controls the number of prefree segments to be
35		reclaimed. If the number of prefree segments is larger than
36		the number of segments in the proportion to the percentage
37		over total volume size, f2fs tries to conduct checkpoint to
38		reclaim the prefree segments to free segments.
39		By default, 5% over total # of segments.
40
41What:		/sys/fs/f2fs/<disk>/main_blkaddr
42Date:		November 2019
43Contact:	"Ramon Pantin" <pantin@google.com>
44Description:	Shows first block address of MAIN area.
45
46What:		/sys/fs/f2fs/<disk>/ipu_policy
47Date:		November 2013
48Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
49Description:	Controls the in-place-update policy.
50		updates in f2fs. User can set:
51
52		===== =============== ===================================================
53		value policy          description
54		0x00  DISABLE         disable IPU(=default option in LFS mode)
55		0x01  FORCE           all the time
56		0x02  SSR             if SSR mode is activated
57		0x04  UTIL            if FS utilization is over threshold
58		0x08  SSR_UTIL        if SSR mode is activated and FS utilization is over
59		                      threshold
60		0x10  FSYNC           activated in fsync path only for high performance
61		                      flash storages. IPU will be triggered only if the
62		                      # of dirty pages over min_fsync_blocks.
63		                      (=default option)
64		0x20  ASYNC           do IPU given by asynchronous write requests
65		0x40  NOCACHE         disable IPU bio cache
66		0x80  HONOR_OPU_WRITE use OPU write prior to IPU write if inode has
67		                      FI_OPU_WRITE flag
68		===== =============== ===================================================
69
70		Refer segment.h for details.
71
72What:		/sys/fs/f2fs/<disk>/min_ipu_util
73Date:		November 2013
74Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
75Description:	Controls the FS utilization condition for the in-place-update
76		policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
77
78What:		/sys/fs/f2fs/<disk>/min_fsync_blocks
79Date:		September 2014
80Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
81Description:	Controls the dirty page count condition for the in-place-update
82		policies.
83
84What:		/sys/fs/f2fs/<disk>/min_seq_blocks
85Date:		August 2018
86Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
87Description:	Controls the dirty page count condition for batched sequential
88		writes in writepages.
89
90What:		/sys/fs/f2fs/<disk>/min_hot_blocks
91Date:		March 2017
92Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
93Description:	Controls the dirty page count condition for redefining hot data.
94
95What:		/sys/fs/f2fs/<disk>/min_ssr_sections
96Date:		October 2017
97Contact:	"Chao Yu" <yuchao0@huawei.com>
98Description:	Controls the free section threshold to trigger SSR allocation.
99		If this is large, SSR mode will be enabled early.
100
101What:		/sys/fs/f2fs/<disk>/max_small_discards
102Date:		November 2013
103Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
104Description:	Controls the issue rate of discard commands that consist of small
105		blocks less than 2MB. The candidates to be discarded are cached until
106		checkpoint is triggered, and issued during the checkpoint.
107		By default, it is disabled with 0.
108
109What:		/sys/fs/f2fs/<disk>/max_ordered_discard
110Date:		October 2022
111Contact:	"Yangtao Li" <frank.li@vivo.com>
112Description:	Controls the maximum ordered discard, the unit size is one block(4KB).
113		Set it to 16 by default.
114
115What:		/sys/fs/f2fs/<disk>/max_discard_request
116Date:		December 2021
117Contact:	"Konstantin Vyshetsky" <vkon@google.com>
118Description:	Controls the number of discards a thread will issue at a time.
119		Higher number will allow the discard thread to finish its work
120		faster, at the cost of higher latency for incoming I/O.
121
122What:		/sys/fs/f2fs/<disk>/min_discard_issue_time
123Date:		December 2021
124Contact:	"Konstantin Vyshetsky" <vkon@google.com>
125Description:	Controls the interval the discard thread will wait between
126		issuing discard requests when there are discards to be issued and
127		no I/O aware interruptions occur.
128
129What:		/sys/fs/f2fs/<disk>/mid_discard_issue_time
130Date:		December 2021
131Contact:	"Konstantin Vyshetsky" <vkon@google.com>
132Description:	Controls the interval the discard thread will wait between
133		issuing discard requests when there are discards to be issued and
134		an I/O aware interruption occurs.
135
136What:		/sys/fs/f2fs/<disk>/max_discard_issue_time
137Date:		December 2021
138Contact:	"Konstantin Vyshetsky" <vkon@google.com>
139Description:	Controls the interval the discard thread will wait when there are
140		no discard operations to be issued.
141
142What:		/sys/fs/f2fs/<disk>/discard_granularity
143Date:		July 2017
144Contact:	"Chao Yu" <yuchao0@huawei.com>
145Description:	Controls discard granularity of inner discard thread. Inner thread
146		will not issue discards with size that is smaller than granularity.
147		The unit size is one block(4KB), now only support configuring
148		in range of [1, 512]. Default value is 16.
149		For small devices, default value is 1.
150
151What:		/sys/fs/f2fs/<disk>/umount_discard_timeout
152Date:		January 2019
153Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
154Description:	Set timeout to issue discard commands during umount.
155	        Default: 5 secs
156
157What:		/sys/fs/f2fs/<disk>/pending_discard
158Date:		November 2021
159Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
160Description:	Shows the number of pending discard commands in the queue.
161
162What:		/sys/fs/f2fs/<disk>/max_victim_search
163Date:		January 2014
164Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
165Description:	Controls the number of trials to find a victim segment
166		when conducting SSR and cleaning operations. The default value
167		is 4096 which covers 8GB block address range.
168
169What:		/sys/fs/f2fs/<disk>/migration_granularity
170Date:		October 2018
171Contact:	"Chao Yu" <yuchao0@huawei.com>
172Description:	Controls migration granularity of garbage collection on large
173		section, it can let GC move partial segment{s} of one section
174		in one GC cycle, so that dispersing heavy overhead GC to
175		multiple lightweight one.
176
177What:		/sys/fs/f2fs/<disk>/dir_level
178Date:		March 2014
179Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
180Description:	Controls the directory level for large directory. If a
181		directory has a number of files, it can reduce the file lookup
182		latency by increasing this dir_level value. Otherwise, it
183		needs to decrease this value to reduce the space overhead.
184		The default value is 0.
185
186What:		/sys/fs/f2fs/<disk>/ram_thresh
187Date:		March 2014
188Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
189Description:	Controls the memory footprint used by free nids and cached
190		nat entries. By default, 1 is set, which indicates
191		10 MB / 1 GB RAM.
192
193What:		/sys/fs/f2fs/<disk>/cp_interval
194Date:		October 2015
195Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
196Description:	Controls the checkpoint timing, set to 60 seconds by default.
197
198What:		/sys/fs/f2fs/<disk>/idle_interval
199Date:		January 2016
200Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
201Description:	Controls the idle timing of system, if there is no FS operation
202		during given interval.
203		Set to 5 seconds by default.
204
205What:		/sys/fs/f2fs/<disk>/discard_idle_interval
206Date:		September 2018
207Contact:	"Chao Yu" <yuchao0@huawei.com>
208Contact:	"Sahitya Tummala" <stummala@codeaurora.org>
209Description:	Controls the idle timing of discard thread given
210		this time interval.
211		Default is 5 secs.
212
213What:		/sys/fs/f2fs/<disk>/gc_idle_interval
214Date:		September 2018
215Contact:	"Chao Yu" <yuchao0@huawei.com>
216Contact:	"Sahitya Tummala" <stummala@codeaurora.org>
217Description:    Controls the idle timing for gc path. Set to 5 seconds by default.
218
219What:		/sys/fs/f2fs/<disk>/iostat_enable
220Date:		August 2017
221Contact:	"Chao Yu" <yuchao0@huawei.com>
222Description:	Controls to enable/disable IO stat.
223
224What:		/sys/fs/f2fs/<disk>/ra_nid_pages
225Date:		October 2015
226Contact:	"Chao Yu" <chao2.yu@samsung.com>
227Description:	Controls the count of nid pages to be readaheaded.
228		When building free nids, F2FS reads NAT blocks ahead for
229		speed up. Default is 0.
230
231What:		/sys/fs/f2fs/<disk>/dirty_nats_ratio
232Date:		January 2016
233Contact:	"Chao Yu" <chao2.yu@samsung.com>
234Description:	Controls dirty nat entries ratio threshold, if current
235		ratio exceeds configured threshold, checkpoint will
236		be triggered for flushing dirty nat entries.
237
238What:		/sys/fs/f2fs/<disk>/lifetime_write_kbytes
239Date:		January 2016
240Contact:	"Shuoran Liu" <liushuoran@huawei.com>
241Description:	Shows total written kbytes issued to disk.
242
243What:		/sys/fs/f2fs/<disk>/features
244Date:		July 2017
245Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
246Description:	<deprecated: should use /sys/fs/f2fs/<disk>/feature_list/>
247		Shows all enabled features in current device.
248		Supported features:
249		encryption, blkzoned, extra_attr, projquota, inode_checksum,
250		flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
251		verity, sb_checksum, casefold, readonly, compression, pin_file.
252
253What:		/sys/fs/f2fs/<disk>/feature_list/
254Date:		June 2021
255Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
256Description:	Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule.
257		Supported on-disk features:
258		encryption, block_zoned (aka blkzoned), extra_attr,
259		project_quota (aka projquota), inode_checksum,
260		flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
261		verity, sb_checksum, casefold, readonly, compression.
262		Note that, pin_file is moved into /sys/fs/f2fs/features/.
263
264What:		/sys/fs/f2fs/features/
265Date:		July 2017
266Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
267Description:	Shows all enabled kernel features.
268		Supported features:
269		encryption, block_zoned, extra_attr, project_quota,
270		inode_checksum, flexible_inline_xattr, quota_ino,
271		inode_crtime, lost_found, verity, sb_checksum,
272		casefold, readonly, compression, test_dummy_encryption_v2,
273		atomic_write, pin_file, encrypted_casefold.
274
275What:		/sys/fs/f2fs/<disk>/inject_rate
276Date:		May 2016
277Contact:	"Sheng Yong" <shengyong1@huawei.com>
278Description:	Controls the injection rate of arbitrary faults.
279
280What:		/sys/fs/f2fs/<disk>/inject_type
281Date:		May 2016
282Contact:	"Sheng Yong" <shengyong1@huawei.com>
283Description:	Controls the injection type of arbitrary faults.
284
285What:		/sys/fs/f2fs/<disk>/dirty_segments
286Date:		October 2017
287Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
288Description:	Shows the number of dirty segments.
289
290What:		/sys/fs/f2fs/<disk>/reserved_blocks
291Date:		June 2017
292Contact:	"Chao Yu" <yuchao0@huawei.com>
293Description:	Controls target reserved blocks in system, the threshold
294		is soft, it could exceed current available user space.
295
296What:		/sys/fs/f2fs/<disk>/current_reserved_blocks
297Date:		October 2017
298Contact:	"Yunlong Song" <yunlong.song@huawei.com>
299Contact:	"Chao Yu" <yuchao0@huawei.com>
300Description:	Shows current reserved blocks in system, it may be temporarily
301		smaller than target_reserved_blocks, but will gradually
302		increase to target_reserved_blocks when more free blocks are
303		freed by user later.
304
305What:		/sys/fs/f2fs/<disk>/gc_urgent
306Date:		August 2017
307Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
308Description:	Do background GC aggressively when set. Set to 0 by default.
309		gc urgent high(1): does GC forcibly in a period of given
310		gc_urgent_sleep_time and ignores I/O idling check. uses greedy
311		GC approach and turns SSR mode on.
312		gc urgent low(2): lowers the bar of checking I/O idling in
313		order to process outstanding discard commands and GC a
314		little bit aggressively. uses cost benefit GC approach.
315		gc urgent mid(3): does GC forcibly in a period of given
316		gc_urgent_sleep_time and executes a mid level of I/O idling check.
317		uses cost benefit GC approach.
318
319What:		/sys/fs/f2fs/<disk>/gc_urgent_sleep_time
320Date:		August 2017
321Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
322Description:	Controls sleep time of GC urgent mode. Set to 500ms by default.
323
324What:		/sys/fs/f2fs/<disk>/readdir_ra
325Date:		November 2017
326Contact:	"Sheng Yong" <shengyong1@huawei.com>
327Description:	Controls readahead inode block in readdir. Enabled by default.
328
329What:		/sys/fs/f2fs/<disk>/gc_pin_file_thresh
330Date:		January 2018
331Contact:	Jaegeuk Kim <jaegeuk@kernel.org>
332Description:	This indicates how many GC can be failed for the pinned
333		file. If it exceeds this, F2FS doesn't guarantee its pinning
334		state. 2048 trials is set by default.
335
336What:		/sys/fs/f2fs/<disk>/extension_list
337Date:		February 2018
338Contact:	"Chao Yu" <yuchao0@huawei.com>
339Description:	Used to control configure extension list:
340		- Query: cat /sys/fs/f2fs/<disk>/extension_list
341		- Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
342		- Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
343		- [h] means add/del hot file extension
344		- [c] means add/del cold file extension
345
346What:		/sys/fs/f2fs/<disk>/unusable
347Date		April 2019
348Contact:	"Daniel Rosenberg" <drosen@google.com>
349Description:	If checkpoint=disable, it displays the number of blocks that
350		are unusable.
351		If checkpoint=enable it displays the number of blocks that
352		would be unusable if checkpoint=disable were to be set.
353
354What:		/sys/fs/f2fs/<disk>/encoding
355Date		July 2019
356Contact:	"Daniel Rosenberg" <drosen@google.com>
357Description:	Displays name and version of the encoding set for the filesystem.
358		If no encoding is set, displays (none)
359
360What:		/sys/fs/f2fs/<disk>/free_segments
361Date:		September 2019
362Contact:	"Hridya Valsaraju" <hridya@google.com>
363Description:	Number of free segments in disk.
364
365What:		/sys/fs/f2fs/<disk>/cp_foreground_calls
366Date:		September 2019
367Contact:	"Hridya Valsaraju" <hridya@google.com>
368Description:	Number of checkpoint operations performed on demand. Available when
369		CONFIG_F2FS_STAT_FS=y.
370
371What:		/sys/fs/f2fs/<disk>/cp_background_calls
372Date:		September 2019
373Contact:	"Hridya Valsaraju" <hridya@google.com>
374Description:	Number of checkpoint operations performed in the background to
375		free segments. Available when CONFIG_F2FS_STAT_FS=y.
376
377What:		/sys/fs/f2fs/<disk>/gc_foreground_calls
378Date:		September 2019
379Contact:	"Hridya Valsaraju" <hridya@google.com>
380Description:	Number of garbage collection operations performed on demand.
381		Available when CONFIG_F2FS_STAT_FS=y.
382
383What:		/sys/fs/f2fs/<disk>/gc_background_calls
384Date:		September 2019
385Contact:	"Hridya Valsaraju" <hridya@google.com>
386Description:	Number of garbage collection operations triggered in background.
387		Available when CONFIG_F2FS_STAT_FS=y.
388
389What:		/sys/fs/f2fs/<disk>/moved_blocks_foreground
390Date:		September 2019
391Contact:	"Hridya Valsaraju" <hridya@google.com>
392Description:	Number of blocks moved by garbage collection in foreground.
393		Available when CONFIG_F2FS_STAT_FS=y.
394
395What:		/sys/fs/f2fs/<disk>/moved_blocks_background
396Date:		September 2019
397Contact:	"Hridya Valsaraju" <hridya@google.com>
398Description:	Number of blocks moved by garbage collection in background.
399		Available when CONFIG_F2FS_STAT_FS=y.
400
401What:		/sys/fs/f2fs/<disk>/avg_vblocks
402Date:		September 2019
403Contact:	"Hridya Valsaraju" <hridya@google.com>
404Description:	Average number of valid blocks.
405		Available when CONFIG_F2FS_STAT_FS=y.
406
407What:		/sys/fs/f2fs/<disk>/mounted_time_sec
408Date:		February 2020
409Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
410Description:	Show the mounted time in secs of this partition.
411
412What:		/sys/fs/f2fs/<disk>/data_io_flag
413Date:		April 2020
414Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
415Description:	Give a way to attach REQ_META|FUA to data writes
416		given temperature-based bits. Now the bits indicate:
417
418		+-------------------+-------------------+
419		|      REQ_META     |      REQ_FUA      |
420		+------+------+-----+------+------+-----+
421		|    5 |    4 |   3 |    2 |    1 |   0 |
422		+------+------+-----+------+------+-----+
423		| Cold | Warm | Hot | Cold | Warm | Hot |
424		+------+------+-----+------+------+-----+
425
426What:		/sys/fs/f2fs/<disk>/node_io_flag
427Date:		June 2020
428Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
429Description:	Give a way to attach REQ_META|FUA to node writes
430		given temperature-based bits. Now the bits indicate:
431
432		+-------------------+-------------------+
433		|      REQ_META     |      REQ_FUA      |
434		+------+------+-----+------+------+-----+
435		|    5 |    4 |   3 |    2 |    1 |   0 |
436		+------+------+-----+------+------+-----+
437		| Cold | Warm | Hot | Cold | Warm | Hot |
438		+------+------+-----+------+------+-----+
439
440What:		/sys/fs/f2fs/<disk>/iostat_period_ms
441Date:		April 2020
442Contact:	"Daeho Jeong" <daehojeong@google.com>
443Description:	Give a way to change iostat_period time. 3secs by default.
444		The new iostat trace gives stats gap given the period.
445What:		/sys/fs/f2fs/<disk>/max_io_bytes
446Date:		December 2020
447Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
448Description:	This gives a control to limit the bio size in f2fs.
449		Default is zero, which will follow underlying block layer limit,
450		whereas, if it has a certain bytes value, f2fs won't submit a
451		bio larger than that size.
452
453What:		/sys/fs/f2fs/<disk>/stat/sb_status
454Date:		December 2020
455Contact:	"Chao Yu" <yuchao0@huawei.com>
456Description:	Show status of f2fs superblock in real time.
457
458		====== ===================== =================================
459		value  sb status macro       description
460		0x1    SBI_IS_DIRTY          dirty flag for checkpoint
461		0x2    SBI_IS_CLOSE          specify unmounting
462		0x4    SBI_NEED_FSCK         need fsck.f2fs to fix
463		0x8    SBI_POR_DOING         recovery is doing or not
464		0x10   SBI_NEED_SB_WRITE     need to recover superblock
465		0x20   SBI_NEED_CP           need to checkpoint
466		0x40   SBI_IS_SHUTDOWN       shutdown by ioctl
467		0x80   SBI_IS_RECOVERED      recovered orphan/data
468		0x100  SBI_CP_DISABLED       CP was disabled last mount
469		0x200  SBI_CP_DISABLED_QUICK CP was disabled quickly
470		0x400  SBI_QUOTA_NEED_FLUSH  need to flush quota info in CP
471		0x800  SBI_QUOTA_SKIP_FLUSH  skip flushing quota in current CP
472		0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted
473		0x2000 SBI_IS_RESIZEFS       resizefs is in process
474		0x4000 SBI_IS_FREEZING       freefs is in process
475		====== ===================== =================================
476
477What:		/sys/fs/f2fs/<disk>/stat/cp_status
478Date:		September 2022
479Contact:	"Chao Yu" <chao.yu@oppo.com>
480Description:	Show status of f2fs checkpoint in real time.
481
482		=============================== ==============================
483		cp flag				value
484		CP_UMOUNT_FLAG			0x00000001
485		CP_ORPHAN_PRESENT_FLAG		0x00000002
486		CP_COMPACT_SUM_FLAG		0x00000004
487		CP_ERROR_FLAG			0x00000008
488		CP_FSCK_FLAG			0x00000010
489		CP_FASTBOOT_FLAG		0x00000020
490		CP_CRC_RECOVERY_FLAG		0x00000040
491		CP_NAT_BITS_FLAG		0x00000080
492		CP_TRIMMED_FLAG			0x00000100
493		CP_NOCRC_RECOVERY_FLAG		0x00000200
494		CP_LARGE_NAT_BITMAP_FLAG	0x00000400
495		CP_QUOTA_NEED_FSCK_FLAG		0x00000800
496		CP_DISABLED_FLAG		0x00001000
497		CP_DISABLED_QUICK_FLAG		0x00002000
498		CP_RESIZEFS_FLAG		0x00004000
499		=============================== ==============================
500
501What:		/sys/fs/f2fs/<disk>/ckpt_thread_ioprio
502Date:		January 2021
503Contact:	"Daeho Jeong" <daehojeong@google.com>
504Description:	Give a way to change checkpoint merge daemon's io priority.
505		Its default value is "be,3", which means "BE" I/O class and
506		I/O priority "3". We can select the class between "rt" and "be",
507		and set the I/O priority within valid range of it. "," delimiter
508		is necessary in between I/O class and priority number.
509
510What:		/sys/fs/f2fs/<disk>/ovp_segments
511Date:		March 2021
512Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
513Description:	Shows the number of overprovision segments.
514
515What:		/sys/fs/f2fs/<disk>/compr_written_block
516Date:		March 2021
517Contact:	"Daeho Jeong" <daehojeong@google.com>
518Description:	Show the block count written after compression since mount. Note
519		that when the compressed blocks are deleted, this count doesn't
520		decrease. If you write "0" here, you can initialize
521		compr_written_block and compr_saved_block to "0".
522
523What:		/sys/fs/f2fs/<disk>/compr_saved_block
524Date:		March 2021
525Contact:	"Daeho Jeong" <daehojeong@google.com>
526Description:	Show the saved block count with compression since mount. Note
527		that when the compressed blocks are deleted, this count doesn't
528		decrease. If you write "0" here, you can initialize
529		compr_written_block and compr_saved_block to "0".
530
531What:		/sys/fs/f2fs/<disk>/compr_new_inode
532Date:		March 2021
533Contact:	"Daeho Jeong" <daehojeong@google.com>
534Description:	Show the count of inode newly enabled for compression since mount.
535		Note that when the compression is disabled for the files, this count
536		doesn't decrease. If you write "0" here, you can initialize
537		compr_new_inode to "0".
538
539What:		/sys/fs/f2fs/<disk>/atgc_candidate_ratio
540Date:		May 2021
541Contact:	"Chao Yu" <yuchao0@huawei.com>
542Description:	When ATGC is on, it controls candidate ratio in order to limit total
543		number of potential victim in all candidates, the value should be in
544		range of [0, 100], by default it was initialized as 20(%).
545
546What:		/sys/fs/f2fs/<disk>/atgc_candidate_count
547Date:		May 2021
548Contact:	"Chao Yu" <yuchao0@huawei.com>
549Description:	When ATGC is on, it controls candidate count in order to limit total
550		number of potential victim in all candidates, by default it was
551		initialized as 10 (sections).
552
553What:		/sys/fs/f2fs/<disk>/atgc_age_weight
554Date:		May 2021
555Contact:	"Chao Yu" <yuchao0@huawei.com>
556Description:	When ATGC is on, it controls age weight to balance weight proportion
557		in between aging and valid blocks, the value should be in range of
558		[0, 100], by default it was initialized as 60(%).
559
560What:		/sys/fs/f2fs/<disk>/atgc_age_threshold
561Date:		May 2021
562Contact:	"Chao Yu" <yuchao0@huawei.com>
563Description:	When ATGC is on, it controls age threshold to bypass GCing young
564		candidates whose age is not beyond the threshold, by default it was
565		initialized as 604800 seconds (equals to 7 days).
566
567What:		/sys/fs/f2fs/<disk>/gc_reclaimed_segments
568Date:		July 2021
569Contact:	"Daeho Jeong" <daehojeong@google.com>
570Description:	Show how many segments have been reclaimed by GC during a specific
571		GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,
572		3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid)
573		You can re-initialize this value to "0".
574
575What:		/sys/fs/f2fs/<disk>/gc_segment_mode
576Date:		July 2021
577Contact:	"Daeho Jeong" <daehojeong@google.com>
578Description:	You can control for which gc mode the "gc_reclaimed_segments" node shows.
579		Refer to the description of the modes in "gc_reclaimed_segments".
580
581What:		/sys/fs/f2fs/<disk>/seq_file_ra_mul
582Date:		July 2021
583Contact:	"Daeho Jeong" <daehojeong@google.com>
584Description:	You can	control the multiplier value of	bdi device readahead window size
585		between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option.
586
587What:		/sys/fs/f2fs/<disk>/max_fragment_chunk
588Date:		August 2021
589Contact:	"Daeho Jeong" <daehojeong@google.com>
590Description:	With "mode=fragment:block" mount options, we can scatter block allocation.
591		f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
592		in the length of 1..<max_fragment_hole> by turns. This value can be set
593		between 1..512 and the default value is 4.
594
595What:		/sys/fs/f2fs/<disk>/max_fragment_hole
596Date:		August 2021
597Contact:	"Daeho Jeong" <daehojeong@google.com>
598Description:	With "mode=fragment:block" mount options, we can scatter block allocation.
599		f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
600		in the length of 1..<max_fragment_hole> by turns. This value can be set
601		between 1..512 and the default value is 4.
602
603What:		/sys/fs/f2fs/<disk>/gc_remaining_trials
604Date:		October 2022
605Contact:	"Yangtao Li" <frank.li@vivo.com>
606Description:	You can set the trial count limit for GC urgent and idle mode with this value.
607		If GC thread gets to the limit, the mode will turn back to GC normal mode.
608		By default, the value is zero, which means there is no limit like before.
609
610What:		/sys/fs/f2fs/<disk>/max_roll_forward_node_blocks
611Date:		January 2022
612Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
613Description:	Controls max # of node block writes to be used for roll forward
614		recovery. This can limit the roll forward recovery time.
615
616What:		/sys/fs/f2fs/<disk>/unusable_blocks_per_sec
617Date:		June 2022
618Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
619Description:	Shows the number of unusable blocks in a section which was defined by
620		the zone capacity reported by underlying zoned device.
621
622What:		/sys/fs/f2fs/<disk>/current_atomic_write
623Date:		July 2022
624Contact:	"Daeho Jeong" <daehojeong@google.com>
625Description:	Show the total current atomic write block count, which is not committed yet.
626		This is a read-only entry.
627
628What:		/sys/fs/f2fs/<disk>/peak_atomic_write
629Date:		July 2022
630Contact:	"Daeho Jeong" <daehojeong@google.com>
631Description:	Show the peak value of total current atomic write block count after boot.
632		If you write "0" here, you can initialize to "0".
633
634What:		/sys/fs/f2fs/<disk>/committed_atomic_block
635Date:		July 2022
636Contact:	"Daeho Jeong" <daehojeong@google.com>
637Description:	Show the accumulated total committed atomic write block count after boot.
638		If you write "0" here, you can initialize to "0".
639
640What:		/sys/fs/f2fs/<disk>/revoked_atomic_block
641Date:		July 2022
642Contact:	"Daeho Jeong" <daehojeong@google.com>
643Description:	Show the accumulated total revoked atomic write block count after boot.
644		If you write "0" here, you can initialize to "0".
645
646What:		/sys/fs/f2fs/<disk>/gc_mode
647Date:		October 2022
648Contact:	"Yangtao Li" <frank.li@vivo.com>
649Description:	Show the current gc_mode as a string.
650		This is a read-only entry.
651
652What:		/sys/fs/f2fs/<disk>/discard_urgent_util
653Date:		November 2022
654Contact:	"Yangtao Li" <frank.li@vivo.com>
655Description:	When space utilization exceeds this, do background DISCARD aggressively.
656		Does DISCARD forcibly in a period of given min_discard_issue_time when the number
657		of discards is not 0 and set discard granularity to 1.
658		Default: 80
659
660What:		/sys/fs/f2fs/<disk>/hot_data_age_threshold
661Date:		November 2022
662Contact:	"Ping Xiong" <xiongping1@xiaomi.com>
663Description:	When DATA SEPARATION is on, it controls the age threshold to indicate
664		the data blocks as hot. By default it was initialized as 262144 blocks
665		(equals to 1GB).
666
667What:		/sys/fs/f2fs/<disk>/warm_data_age_threshold
668Date:		November 2022
669Contact:	"Ping Xiong" <xiongping1@xiaomi.com>
670Description:	When DATA SEPARATION is on, it controls the age threshold to indicate
671		the data blocks as warm. By default it was initialized as 2621440 blocks
672		(equals to 10GB).
673
674What:		/sys/fs/f2fs/<disk>/fault_rate
675Date:		May 2016
676Contact:	"Sheng Yong" <shengyong@oppo.com>
677Contact:	"Chao Yu" <chao@kernel.org>
678Description:	Enable fault injection in all supported types with
679		specified injection rate.
680
681What:		/sys/fs/f2fs/<disk>/fault_type
682Date:		May 2016
683Contact:	"Sheng Yong" <shengyong@oppo.com>
684Contact:	"Chao Yu" <chao@kernel.org>
685Description:	Support configuring fault injection type, should be
686		enabled with fault_injection option, fault type value
687		is shown below, it supports single or combined type.
688
689		===================      ===========
690		Type_Name                Type_Value
691		===================      ===========
692		FAULT_KMALLOC            0x000000001
693		FAULT_KVMALLOC           0x000000002
694		FAULT_PAGE_ALLOC         0x000000004
695		FAULT_PAGE_GET           0x000000008
696		FAULT_ALLOC_BIO          0x000000010 (obsolete)
697		FAULT_ALLOC_NID          0x000000020
698		FAULT_ORPHAN             0x000000040
699		FAULT_BLOCK              0x000000080
700		FAULT_DIR_DEPTH          0x000000100
701		FAULT_EVICT_INODE        0x000000200
702		FAULT_TRUNCATE           0x000000400
703		FAULT_READ_IO            0x000000800
704		FAULT_CHECKPOINT         0x000001000
705		FAULT_DISCARD            0x000002000
706		FAULT_WRITE_IO           0x000004000
707		FAULT_SLAB_ALLOC         0x000008000
708		FAULT_DQUOT_INIT         0x000010000
709		FAULT_LOCK_OP            0x000020000
710		FAULT_BLKADDR            0x000040000
711		===================      ===========
712
713What:		/sys/fs/f2fs/<disk>/discard_io_aware_gran
714Date:		January 2023
715Contact:	"Yangtao Li" <frank.li@vivo.com>
716Description:	Controls background discard granularity of inner discard thread
717		when is not in idle. Inner thread will not issue discards with size that
718		is smaller than granularity. The unit size is one block(4KB), now only
719		support configuring in range of [0, 512].
720		Default: 512
721
722What:		/sys/fs/f2fs/<disk>/last_age_weight
723Date:		January 2023
724Contact:	"Ping Xiong" <xiongping1@xiaomi.com>
725Description:	When DATA SEPARATION is on, it controls the weight of last data block age.
726
727What:		/sys/fs/f2fs/<disk>/compress_watermark
728Date:		February 2023
729Contact:	"Yangtao Li" <frank.li@vivo.com>
730Description:	When compress cache is on, it controls free memory watermark
731		in order to limit caching compress page. If free memory is lower
732		than watermark, then deny caching compress page. The value should be in
733		range of (0, 100], by default it was initialized as 20(%).
734
735What:		/sys/fs/f2fs/<disk>/compress_percent
736Date:		February 2023
737Contact:	"Yangtao Li" <frank.li@vivo.com>
738Description:	When compress cache is on, it controls cached page
739		percent(compress pages / free_ram) in order to limit caching compress page.
740		If cached page percent exceed threshold, then deny caching compress page.
741		The value should be in range of (0, 100], by default it was initialized
742		as 20(%).
743