1 What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
2 Date: July 2013
3 Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
4 Description: Controls the maximum sleep time for gc_thread. Time
5 is in milliseconds.
6
7 What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
8 Date: July 2013
9 Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
10 Description: Controls the minimum sleep time for gc_thread. Time
11 is in milliseconds.
12
13 What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
14 Date: July 2013
15 Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
16 Description: Controls the default sleep time for gc_thread. Time
17 is in milliseconds.
18
19 What: /sys/fs/f2fs/<disk>/gc_idle
20 Date: July 2013
21 Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
22 Description: 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
31 What: /sys/fs/f2fs/<disk>/reclaim_segments
32 Date: October 2013
33 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
34 Description: 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
41 What: /sys/fs/f2fs/<disk>/main_blkaddr
42 Date: November 2019
43 Contact: "Ramon Pantin" <pantin@google.com>
44 Description: Shows first block address of MAIN area.
45
46 What: /sys/fs/f2fs/<disk>/ipu_policy
47 Date: November 2013
48 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
49 Description: 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
72 What: /sys/fs/f2fs/<disk>/min_ipu_util
73 Date: November 2013
74 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
75 Description: 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
78 What: /sys/fs/f2fs/<disk>/min_fsync_blocks
79 Date: September 2014
80 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
81 Description: Controls the dirty page count condition for the in-place-update
82 policies.
83
84 What: /sys/fs/f2fs/<disk>/min_seq_blocks
85 Date: August 2018
86 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
87 Description: Controls the dirty page count condition for batched sequential
88 writes in writepages.
89
90 What: /sys/fs/f2fs/<disk>/min_hot_blocks
91 Date: March 2017
92 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
93 Description: Controls the dirty page count condition for redefining hot data.
94
95 What: /sys/fs/f2fs/<disk>/min_ssr_sections
96 Date: October 2017
97 Contact: "Chao Yu" <yuchao0@huawei.com>
98 Description: Controls the free section threshold to trigger SSR allocation.
99 If this is large, SSR mode will be enabled early.
100
101 What: /sys/fs/f2fs/<disk>/max_small_discards
102 Date: November 2013
103 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
104 Description: Controls the issue rate of discard commands that consist of small
105 blocks less than 2MB. The candidates to be discarded are cached during
106 checkpoint, and issued by issue_discard thread after checkpoint.
107 It is enabled by default.
108
109 What: /sys/fs/f2fs/<disk>/max_ordered_discard
110 Date: October 2022
111 Contact: "Yangtao Li" <frank.li@vivo.com>
112 Description: Controls the maximum ordered discard, the unit size is one block(4KB).
113 Set it to 16 by default.
114
115 What: /sys/fs/f2fs/<disk>/max_discard_request
116 Date: December 2021
117 Contact: "Konstantin Vyshetsky" <vkon@google.com>
118 Description: 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
122 What: /sys/fs/f2fs/<disk>/min_discard_issue_time
123 Date: December 2021
124 Contact: "Konstantin Vyshetsky" <vkon@google.com>
125 Description: 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
129 What: /sys/fs/f2fs/<disk>/mid_discard_issue_time
130 Date: December 2021
131 Contact: "Konstantin Vyshetsky" <vkon@google.com>
132 Description: 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
136 What: /sys/fs/f2fs/<disk>/max_discard_issue_time
137 Date: December 2021
138 Contact: "Konstantin Vyshetsky" <vkon@google.com>
139 Description: Controls the interval the discard thread will wait when there are
140 no discard operations to be issued.
141
142 What: /sys/fs/f2fs/<disk>/discard_granularity
143 Date: July 2017
144 Contact: "Chao Yu" <yuchao0@huawei.com>
145 Description: 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
151 What: /sys/fs/f2fs/<disk>/umount_discard_timeout
152 Date: January 2019
153 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
154 Description: Set timeout to issue discard commands during umount.
155 Default: 5 secs
156
157 What: /sys/fs/f2fs/<disk>/pending_discard
158 Date: November 2021
159 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
160 Description: Shows the number of pending discard commands in the queue.
161
162 What: /sys/fs/f2fs/<disk>/max_victim_search
163 Date: January 2014
164 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
165 Description: 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
169 What: /sys/fs/f2fs/<disk>/migration_granularity
170 Date: October 2018
171 Contact: "Chao Yu" <yuchao0@huawei.com>
172 Description: 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
177 What: /sys/fs/f2fs/<disk>/dir_level
178 Date: March 2014
179 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
180 Description: 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
186 What: /sys/fs/f2fs/<disk>/ram_thresh
187 Date: March 2014
188 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
189 Description: 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
193 What: /sys/fs/f2fs/<disk>/cp_interval
194 Date: October 2015
195 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
196 Description: Controls the checkpoint timing, set to 60 seconds by default.
197
198 What: /sys/fs/f2fs/<disk>/idle_interval
199 Date: January 2016
200 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
201 Description: Controls the idle timing of system, if there is no FS operation
202 during given interval.
203 Set to 5 seconds by default.
204
205 What: /sys/fs/f2fs/<disk>/discard_idle_interval
206 Date: September 2018
207 Contact: "Chao Yu" <yuchao0@huawei.com>
208 Contact: "Sahitya Tummala" <quic_stummala@quicinc.com>
209 Description: Controls the idle timing of discard thread given
210 this time interval.
211 Default is 5 secs.
212
213 What: /sys/fs/f2fs/<disk>/gc_idle_interval
214 Date: September 2018
215 Contact: "Chao Yu" <yuchao0@huawei.com>
216 Contact: "Sahitya Tummala" <quic_stummala@quicinc.com>
217 Description: Controls the idle timing for gc path. Set to 5 seconds by default.
218
219 What: /sys/fs/f2fs/<disk>/iostat_enable
220 Date: August 2017
221 Contact: "Chao Yu" <yuchao0@huawei.com>
222 Description: Controls to enable/disable IO stat.
223
224 What: /sys/fs/f2fs/<disk>/ra_nid_pages
225 Date: October 2015
226 Contact: "Chao Yu" <chao2.yu@samsung.com>
227 Description: 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
231 What: /sys/fs/f2fs/<disk>/dirty_nats_ratio
232 Date: January 2016
233 Contact: "Chao Yu" <chao2.yu@samsung.com>
234 Description: Controls dirty nat entries ratio threshold, if current
235 ratio exceeds configured threshold, checkpoint will
236 be triggered for flushing dirty nat entries.
237
238 What: /sys/fs/f2fs/<disk>/lifetime_write_kbytes
239 Date: January 2016
240 Contact: "Shuoran Liu" <liushuoran@huawei.com>
241 Description: Shows total written kbytes issued to disk.
242
243 What: /sys/fs/f2fs/<disk>/features
244 Date: July 2017
245 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
246 Description: <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
253 What: /sys/fs/f2fs/<disk>/feature_list/
254 Date: June 2021
255 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
256 Description: 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
264 What: /sys/fs/f2fs/features/
265 Date: July 2017
266 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
267 Description: 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
275 What: /sys/fs/f2fs/<disk>/inject_rate
276 Date: May 2016
277 Contact: "Sheng Yong" <shengyong1@huawei.com>
278 Description: Controls the injection rate of arbitrary faults.
279
280 What: /sys/fs/f2fs/<disk>/inject_type
281 Date: May 2016
282 Contact: "Sheng Yong" <shengyong1@huawei.com>
283 Description: Controls the injection type of arbitrary faults.
284
285 What: /sys/fs/f2fs/<disk>/dirty_segments
286 Date: October 2017
287 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
288 Description: Shows the number of dirty segments.
289
290 What: /sys/fs/f2fs/<disk>/reserved_blocks
291 Date: June 2017
292 Contact: "Chao Yu" <yuchao0@huawei.com>
293 Description: Controls target reserved blocks in system, the threshold
294 is soft, it could exceed current available user space.
295
296 What: /sys/fs/f2fs/<disk>/current_reserved_blocks
297 Date: October 2017
298 Contact: "Yunlong Song" <yunlong.song@huawei.com>
299 Contact: "Chao Yu" <yuchao0@huawei.com>
300 Description: 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
305 What: /sys/fs/f2fs/<disk>/gc_urgent
306 Date: August 2017
307 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
308 Description: 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
319 What: /sys/fs/f2fs/<disk>/gc_urgent_sleep_time
320 Date: August 2017
321 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
322 Description: Controls sleep time of GC urgent mode. Set to 500ms by default.
323
324 What: /sys/fs/f2fs/<disk>/readdir_ra
325 Date: November 2017
326 Contact: "Sheng Yong" <shengyong1@huawei.com>
327 Description: Controls readahead inode block in readdir. Enabled by default.
328
329 What: /sys/fs/f2fs/<disk>/gc_pin_file_thresh
330 Date: January 2018
331 Contact: Jaegeuk Kim <jaegeuk@kernel.org>
332 Description: 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, and 65535 as maximum.
335
336 What: /sys/fs/f2fs/<disk>/extension_list
337 Date: February 2018
338 Contact: "Chao Yu" <yuchao0@huawei.com>
339 Description: 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
346 What: /sys/fs/f2fs/<disk>/unusable
347 Date April 2019
348 Contact: "Daniel Rosenberg" <drosen@google.com>
349 Description: 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
354 What: /sys/fs/f2fs/<disk>/encoding
355 Date July 2019
356 Contact: "Daniel Rosenberg" <drosen@google.com>
357 Description: Displays name and version of the encoding set for the filesystem.
358 If no encoding is set, displays (none)
359
360 What: /sys/fs/f2fs/<disk>/free_segments
361 Date: September 2019
362 Contact: "Hridya Valsaraju" <hridya@google.com>
363 Description: Number of free segments in disk.
364
365 What: /sys/fs/f2fs/<disk>/cp_foreground_calls
366 Date: September 2019
367 Contact: "Hridya Valsaraju" <hridya@google.com>
368 Description: Number of checkpoint operations performed on demand. Available when
369 CONFIG_F2FS_STAT_FS=y.
370
371 What: /sys/fs/f2fs/<disk>/cp_background_calls
372 Date: September 2019
373 Contact: "Hridya Valsaraju" <hridya@google.com>
374 Description: Number of checkpoint operations performed in the background to
375 free segments. Available when CONFIG_F2FS_STAT_FS=y.
376
377 What: /sys/fs/f2fs/<disk>/gc_foreground_calls
378 Date: September 2019
379 Contact: "Hridya Valsaraju" <hridya@google.com>
380 Description: Number of garbage collection operations performed on demand.
381 Available when CONFIG_F2FS_STAT_FS=y.
382
383 What: /sys/fs/f2fs/<disk>/gc_background_calls
384 Date: September 2019
385 Contact: "Hridya Valsaraju" <hridya@google.com>
386 Description: Number of garbage collection operations triggered in background.
387 Available when CONFIG_F2FS_STAT_FS=y.
388
389 What: /sys/fs/f2fs/<disk>/moved_blocks_foreground
390 Date: September 2019
391 Contact: "Hridya Valsaraju" <hridya@google.com>
392 Description: Number of blocks moved by garbage collection in foreground.
393 Available when CONFIG_F2FS_STAT_FS=y.
394
395 What: /sys/fs/f2fs/<disk>/moved_blocks_background
396 Date: September 2019
397 Contact: "Hridya Valsaraju" <hridya@google.com>
398 Description: Number of blocks moved by garbage collection in background.
399 Available when CONFIG_F2FS_STAT_FS=y.
400
401 What: /sys/fs/f2fs/<disk>/avg_vblocks
402 Date: September 2019
403 Contact: "Hridya Valsaraju" <hridya@google.com>
404 Description: Average number of valid blocks.
405 Available when CONFIG_F2FS_STAT_FS=y.
406
407 What: /sys/fs/f2fs/<disk>/mounted_time_sec
408 Date: February 2020
409 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
410 Description: Show the mounted time in secs of this partition.
411
412 What: /sys/fs/f2fs/<disk>/data_io_flag
413 Date: April 2020
414 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
415 Description: 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
426 What: /sys/fs/f2fs/<disk>/node_io_flag
427 Date: June 2020
428 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
429 Description: 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
440 What: /sys/fs/f2fs/<disk>/iostat_period_ms
441 Date: April 2020
442 Contact: "Daeho Jeong" <daehojeong@google.com>
443 Description: Give a way to change iostat_period time. 3secs by default.
444 The new iostat trace gives stats gap given the period.
445 What: /sys/fs/f2fs/<disk>/max_io_bytes
446 Date: December 2020
447 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
448 Description: 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
453 What: /sys/fs/f2fs/<disk>/stat/sb_status
454 Date: December 2020
455 Contact: "Chao Yu" <yuchao0@huawei.com>
456 Description: 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
477 What: /sys/fs/f2fs/<disk>/stat/cp_status
478 Date: September 2022
479 Contact: "Chao Yu" <chao.yu@oppo.com>
480 Description: 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
501 What: /sys/fs/f2fs/<disk>/stat/issued_discard
502 Date: December 2023
503 Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
504 Description: Shows the number of issued discard.
505
506 What: /sys/fs/f2fs/<disk>/stat/queued_discard
507 Date: December 2023
508 Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
509 Description: Shows the number of queued discard.
510
511 What: /sys/fs/f2fs/<disk>/stat/undiscard_blks
512 Date: December 2023
513 Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com>
514 Description: Shows the total number of undiscard blocks.
515
516 What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
517 Date: January 2021
518 Contact: "Daeho Jeong" <daehojeong@google.com>
519 Description: Give a way to change checkpoint merge daemon's io priority.
520 Its default value is "be,3", which means "BE" I/O class and
521 I/O priority "3". We can select the class between "rt" and "be",
522 and set the I/O priority within valid range of it. "," delimiter
523 is necessary in between I/O class and priority number.
524
525 What: /sys/fs/f2fs/<disk>/ovp_segments
526 Date: March 2021
527 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
528 Description: Shows the number of overprovision segments.
529
530 What: /sys/fs/f2fs/<disk>/compr_written_block
531 Date: March 2021
532 Contact: "Daeho Jeong" <daehojeong@google.com>
533 Description: Show the block count written after compression since mount. Note
534 that when the compressed blocks are deleted, this count doesn't
535 decrease. If you write "0" here, you can initialize
536 compr_written_block and compr_saved_block to "0".
537
538 What: /sys/fs/f2fs/<disk>/compr_saved_block
539 Date: March 2021
540 Contact: "Daeho Jeong" <daehojeong@google.com>
541 Description: Show the saved block count with compression since mount. Note
542 that when the compressed blocks are deleted, this count doesn't
543 decrease. If you write "0" here, you can initialize
544 compr_written_block and compr_saved_block to "0".
545
546 What: /sys/fs/f2fs/<disk>/compr_new_inode
547 Date: March 2021
548 Contact: "Daeho Jeong" <daehojeong@google.com>
549 Description: Show the count of inode newly enabled for compression since mount.
550 Note that when the compression is disabled for the files, this count
551 doesn't decrease. If you write "0" here, you can initialize
552 compr_new_inode to "0".
553
554 What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio
555 Date: May 2021
556 Contact: "Chao Yu" <yuchao0@huawei.com>
557 Description: When ATGC is on, it controls candidate ratio in order to limit total
558 number of potential victim in all candidates, the value should be in
559 range of [0, 100], by default it was initialized as 20(%).
560
561 What: /sys/fs/f2fs/<disk>/atgc_candidate_count
562 Date: May 2021
563 Contact: "Chao Yu" <yuchao0@huawei.com>
564 Description: When ATGC is on, it controls candidate count in order to limit total
565 number of potential victim in all candidates, by default it was
566 initialized as 10 (sections).
567
568 What: /sys/fs/f2fs/<disk>/atgc_age_weight
569 Date: May 2021
570 Contact: "Chao Yu" <yuchao0@huawei.com>
571 Description: When ATGC is on, it controls age weight to balance weight proportion
572 in between aging and valid blocks, the value should be in range of
573 [0, 100], by default it was initialized as 60(%).
574
575 What: /sys/fs/f2fs/<disk>/atgc_age_threshold
576 Date: May 2021
577 Contact: "Chao Yu" <yuchao0@huawei.com>
578 Description: When ATGC is on, it controls age threshold to bypass GCing young
579 candidates whose age is not beyond the threshold, by default it was
580 initialized as 604800 seconds (equals to 7 days).
581
582 What: /sys/fs/f2fs/<disk>/atgc_enabled
583 Date: Feb 2024
584 Contact: "Jinbao Liu" <liujinbao1@xiaomi.com>
585 Description: It represents whether ATGC is on or off. The value is 1 which
586 indicates that ATGC is on, and 0 indicates that it is off.
587
588 What: /sys/fs/f2fs/<disk>/gc_reclaimed_segments
589 Date: July 2021
590 Contact: "Daeho Jeong" <daehojeong@google.com>
591 Description: Show how many segments have been reclaimed by GC during a specific
592 GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,
593 3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid)
594 You can re-initialize this value to "0".
595
596 What: /sys/fs/f2fs/<disk>/gc_segment_mode
597 Date: July 2021
598 Contact: "Daeho Jeong" <daehojeong@google.com>
599 Description: You can control for which gc mode the "gc_reclaimed_segments" node shows.
600 Refer to the description of the modes in "gc_reclaimed_segments".
601
602 What: /sys/fs/f2fs/<disk>/seq_file_ra_mul
603 Date: July 2021
604 Contact: "Daeho Jeong" <daehojeong@google.com>
605 Description: You can control the multiplier value of bdi device readahead window size
606 between 2 (default) and 256 for POSIX_FADV_SEQUENTIAL advise option.
607
608 What: /sys/fs/f2fs/<disk>/max_fragment_chunk
609 Date: August 2021
610 Contact: "Daeho Jeong" <daehojeong@google.com>
611 Description: With "mode=fragment:block" mount options, we can scatter block allocation.
612 f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
613 in the length of 1..<max_fragment_hole> by turns. This value can be set
614 between 1..512 and the default value is 4.
615
616 What: /sys/fs/f2fs/<disk>/max_fragment_hole
617 Date: August 2021
618 Contact: "Daeho Jeong" <daehojeong@google.com>
619 Description: With "mode=fragment:block" mount options, we can scatter block allocation.
620 f2fs will allocate 1..<max_fragment_chunk> blocks in a chunk and make a hole
621 in the length of 1..<max_fragment_hole> by turns. This value can be set
622 between 1..512 and the default value is 4.
623
624 What: /sys/fs/f2fs/<disk>/gc_remaining_trials
625 Date: October 2022
626 Contact: "Yangtao Li" <frank.li@vivo.com>
627 Description: You can set the trial count limit for GC urgent and idle mode with this value.
628 If GC thread gets to the limit, the mode will turn back to GC normal mode.
629 By default, the value is zero, which means there is no limit like before.
630
631 What: /sys/fs/f2fs/<disk>/max_roll_forward_node_blocks
632 Date: January 2022
633 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
634 Description: Controls max # of node block writes to be used for roll forward
635 recovery. This can limit the roll forward recovery time.
636
637 What: /sys/fs/f2fs/<disk>/unusable_blocks_per_sec
638 Date: June 2022
639 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
640 Description: Shows the number of unusable blocks in a section which was defined by
641 the zone capacity reported by underlying zoned device.
642
643 What: /sys/fs/f2fs/<disk>/current_atomic_write
644 Date: July 2022
645 Contact: "Daeho Jeong" <daehojeong@google.com>
646 Description: Show the total current atomic write block count, which is not committed yet.
647 This is a read-only entry.
648
649 What: /sys/fs/f2fs/<disk>/peak_atomic_write
650 Date: July 2022
651 Contact: "Daeho Jeong" <daehojeong@google.com>
652 Description: Show the peak value of total current atomic write block count after boot.
653 If you write "0" here, you can initialize to "0".
654
655 What: /sys/fs/f2fs/<disk>/committed_atomic_block
656 Date: July 2022
657 Contact: "Daeho Jeong" <daehojeong@google.com>
658 Description: Show the accumulated total committed atomic write block count after boot.
659 If you write "0" here, you can initialize to "0".
660
661 What: /sys/fs/f2fs/<disk>/revoked_atomic_block
662 Date: July 2022
663 Contact: "Daeho Jeong" <daehojeong@google.com>
664 Description: Show the accumulated total revoked atomic write block count after boot.
665 If you write "0" here, you can initialize to "0".
666
667 What: /sys/fs/f2fs/<disk>/gc_mode
668 Date: October 2022
669 Contact: "Yangtao Li" <frank.li@vivo.com>
670 Description: Show the current gc_mode as a string.
671 This is a read-only entry.
672
673 What: /sys/fs/f2fs/<disk>/discard_urgent_util
674 Date: November 2022
675 Contact: "Yangtao Li" <frank.li@vivo.com>
676 Description: When space utilization exceeds this, do background DISCARD aggressively.
677 Does DISCARD forcibly in a period of given min_discard_issue_time when the number
678 of discards is not 0 and set discard granularity to 1.
679 Default: 80
680
681 What: /sys/fs/f2fs/<disk>/hot_data_age_threshold
682 Date: November 2022
683 Contact: "Ping Xiong" <xiongping1@xiaomi.com>
684 Description: When DATA SEPARATION is on, it controls the age threshold to indicate
685 the data blocks as hot. By default it was initialized as 262144 blocks
686 (equals to 1GB).
687
688 What: /sys/fs/f2fs/<disk>/warm_data_age_threshold
689 Date: November 2022
690 Contact: "Ping Xiong" <xiongping1@xiaomi.com>
691 Description: When DATA SEPARATION is on, it controls the age threshold to indicate
692 the data blocks as warm. By default it was initialized as 2621440 blocks
693 (equals to 10GB).
694
695 What: /sys/fs/f2fs/<disk>/fault_rate
696 Date: May 2016
697 Contact: "Sheng Yong" <shengyong@oppo.com>
698 Contact: "Chao Yu" <chao@kernel.org>
699 Description: Enable fault injection in all supported types with
700 specified injection rate.
701
702 What: /sys/fs/f2fs/<disk>/fault_type
703 Date: May 2016
704 Contact: "Sheng Yong" <shengyong@oppo.com>
705 Contact: "Chao Yu" <chao@kernel.org>
706 Description: Support configuring fault injection type, should be
707 enabled with fault_injection option, fault type value
708 is shown below, it supports single or combined type.
709
710 =========================== ===========
711 Type_Name Type_Value
712 =========================== ===========
713 FAULT_KMALLOC 0x000000001
714 FAULT_KVMALLOC 0x000000002
715 FAULT_PAGE_ALLOC 0x000000004
716 FAULT_PAGE_GET 0x000000008
717 FAULT_ALLOC_BIO 0x000000010 (obsolete)
718 FAULT_ALLOC_NID 0x000000020
719 FAULT_ORPHAN 0x000000040
720 FAULT_BLOCK 0x000000080
721 FAULT_DIR_DEPTH 0x000000100
722 FAULT_EVICT_INODE 0x000000200
723 FAULT_TRUNCATE 0x000000400
724 FAULT_READ_IO 0x000000800
725 FAULT_CHECKPOINT 0x000001000
726 FAULT_DISCARD 0x000002000
727 FAULT_WRITE_IO 0x000004000
728 FAULT_SLAB_ALLOC 0x000008000
729 FAULT_DQUOT_INIT 0x000010000
730 FAULT_LOCK_OP 0x000020000
731 FAULT_BLKADDR_VALIDITY 0x000040000
732 FAULT_BLKADDR_CONSISTENCE 0x000080000
733 FAULT_NO_SEGMENT 0x000100000
734 =========================== ===========
735
736 What: /sys/fs/f2fs/<disk>/discard_io_aware_gran
737 Date: January 2023
738 Contact: "Yangtao Li" <frank.li@vivo.com>
739 Description: Controls background discard granularity of inner discard thread
740 when is not in idle. Inner thread will not issue discards with size that
741 is smaller than granularity. The unit size is one block(4KB), now only
742 support configuring in range of [0, 512].
743 Default: 512
744
745 What: /sys/fs/f2fs/<disk>/last_age_weight
746 Date: January 2023
747 Contact: "Ping Xiong" <xiongping1@xiaomi.com>
748 Description: When DATA SEPARATION is on, it controls the weight of last data block age.
749
750 What: /sys/fs/f2fs/<disk>/compress_watermark
751 Date: February 2023
752 Contact: "Yangtao Li" <frank.li@vivo.com>
753 Description: When compress cache is on, it controls free memory watermark
754 in order to limit caching compress page. If free memory is lower
755 than watermark, then deny caching compress page. The value should be in
756 range of (0, 100], by default it was initialized as 20(%).
757
758 What: /sys/fs/f2fs/<disk>/compress_percent
759 Date: February 2023
760 Contact: "Yangtao Li" <frank.li@vivo.com>
761 Description: When compress cache is on, it controls cached page
762 percent(compress pages / free_ram) in order to limit caching compress page.
763 If cached page percent exceed threshold, then deny caching compress page.
764 The value should be in range of (0, 100], by default it was initialized
765 as 20(%).
766
767 What: /sys/fs/f2fs/<disk>/discard_io_aware
768 Date: November 2023
769 Contact: "Chao Yu" <chao@kernel.org>
770 Description: It controls to enable/disable IO aware feature for background discard.
771 By default, the value is 1 which indicates IO aware is on.
772
773 What: /sys/fs/f2fs/<disk>/blkzone_alloc_policy
774 Date: July 2024
775 Contact: "Yuanhong Liao" <liaoyuanhong@vivo.com>
776 Description: The zone UFS we are currently using consists of two parts:
777 conventional zones and sequential zones. It can be used to control which part
778 to prioritize for writes, with a default value of 0.
779
780 ======================== =========================================
781 value description
782 blkzone_alloc_policy = 0 Prioritize writing to sequential zones
783 blkzone_alloc_policy = 1 Only allow writing to sequential zones
784 blkzone_alloc_policy = 2 Prioritize writing to conventional zones
785 ======================== =========================================
786
787 What: /sys/fs/f2fs/<disk>/migration_window_granularity
788 Date: September 2024
789 Contact: "Daeho Jeong" <daehojeong@google.com>
790 Description: Controls migration window granularity of garbage collection on large
791 section. it can control the scanning window granularity for GC migration
792 in a unit of segment, while migration_granularity controls the number
793 of segments which can be migrated at the same turn.
794
795 What: /sys/fs/f2fs/<disk>/reserved_segments
796 Date: September 2024
797 Contact: "Daeho Jeong" <daehojeong@google.com>
798 Description: In order to fine tune GC behavior, we can control the number of
799 reserved segments.
800
801 What: /sys/fs/f2fs/<disk>/gc_no_zoned_gc_percent
802 Date: September 2024
803 Contact: "Daeho Jeong" <daehojeong@google.com>
804 Description: If the percentage of free sections over total sections is above this
805 number, F2FS do not garbage collection for zoned devices through the
806 background GC thread. the default number is "60".
807
808 What: /sys/fs/f2fs/<disk>/gc_boost_zoned_gc_percent
809 Date: September 2024
810 Contact: "Daeho Jeong" <daehojeong@google.com>
811 Description: If the percentage of free sections over total sections is under this
812 number, F2FS boosts garbage collection for zoned devices through the
813 background GC thread. the default number is "25".
814
815 What: /sys/fs/f2fs/<disk>/gc_valid_thresh_ratio
816 Date: September 2024
817 Contact: "Daeho Jeong" <daehojeong@google.com>
818 Description: It controls the valid block ratio threshold not to trigger excessive GC
819 for zoned deivces. The initial value of it is 95(%). F2FS will stop the
820 background GC thread from intiating GC for sections having valid blocks
821 exceeding the ratio.
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