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: 45 Shows first block address of MAIN area. 46 47What: /sys/fs/f2fs/<disk>/ipu_policy 48Date: November 2013 49Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 50Description: Controls the in-place-update policy. 51 updates in f2fs. User can set: 52 53 ==== ================= 54 0x01 F2FS_IPU_FORCE 55 0x02 F2FS_IPU_SSR 56 0x04 F2FS_IPU_UTIL 57 0x08 F2FS_IPU_SSR_UTIL 58 0x10 F2FS_IPU_FSYNC 59 0x20 F2FS_IPU_ASYNC, 60 0x40 F2FS_IPU_NOCACHE 61 ==== ================= 62 63 Refer segment.h for details. 64 65What: /sys/fs/f2fs/<disk>/min_ipu_util 66Date: November 2013 67Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 68Description: Controls the FS utilization condition for the in-place-update 69 policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies. 70 71What: /sys/fs/f2fs/<disk>/min_fsync_blocks 72Date: September 2014 73Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 74Description: Controls the dirty page count condition for the in-place-update 75 policies. 76 77What: /sys/fs/f2fs/<disk>/min_seq_blocks 78Date: August 2018 79Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 80Description: Controls the dirty page count condition for batched sequential 81 writes in writepages. 82 83What: /sys/fs/f2fs/<disk>/min_hot_blocks 84Date: March 2017 85Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 86Description: Controls the dirty page count condition for redefining hot data. 87 88What: /sys/fs/f2fs/<disk>/min_ssr_sections 89Date: October 2017 90Contact: "Chao Yu" <yuchao0@huawei.com> 91Description: Controls the free section threshold to trigger SSR allocation. 92 If this is large, SSR mode will be enabled early. 93 94What: /sys/fs/f2fs/<disk>/max_small_discards 95Date: November 2013 96Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 97Description: Controls the issue rate of discard commands that consist of small 98 blocks less than 2MB. The candidates to be discarded are cached until 99 checkpoint is triggered, and issued during the checkpoint. 100 By default, it is disabled with 0. 101 102What: /sys/fs/f2fs/<disk>/discard_granularity 103Date: July 2017 104Contact: "Chao Yu" <yuchao0@huawei.com> 105Description: Controls discard granularity of inner discard thread. Inner thread 106 will not issue discards with size that is smaller than granularity. 107 The unit size is one block(4KB), now only support configuring 108 in range of [1, 512]. Default value is 4(=16KB). 109 110What: /sys/fs/f2fs/<disk>/umount_discard_timeout 111Date: January 2019 112Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 113Description: Set timeout to issue discard commands during umount. 114 Default: 5 secs 115 116What: /sys/fs/f2fs/<disk>/max_victim_search 117Date: January 2014 118Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 119Description: Controls the number of trials to find a victim segment 120 when conducting SSR and cleaning operations. The default value 121 is 4096 which covers 8GB block address range. 122 123What: /sys/fs/f2fs/<disk>/migration_granularity 124Date: October 2018 125Contact: "Chao Yu" <yuchao0@huawei.com> 126Description: Controls migration granularity of garbage collection on large 127 section, it can let GC move partial segment{s} of one section 128 in one GC cycle, so that dispersing heavy overhead GC to 129 multiple lightweight one. 130 131What: /sys/fs/f2fs/<disk>/dir_level 132Date: March 2014 133Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 134Description: Controls the directory level for large directory. If a 135 directory has a number of files, it can reduce the file lookup 136 latency by increasing this dir_level value. Otherwise, it 137 needs to decrease this value to reduce the space overhead. 138 The default value is 0. 139 140What: /sys/fs/f2fs/<disk>/ram_thresh 141Date: March 2014 142Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> 143Description: Controls the memory footprint used by free nids and cached 144 nat entries. By default, 1 is set, which indicates 145 10 MB / 1 GB RAM. 146 147What: /sys/fs/f2fs/<disk>/batched_trim_sections 148Date: February 2015 149Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 150Description: Controls the trimming rate in batch mode. 151 <deprecated> 152 153What: /sys/fs/f2fs/<disk>/cp_interval 154Date: October 2015 155Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 156Description: Controls the checkpoint timing, set to 60 seconds by default. 157 158What: /sys/fs/f2fs/<disk>/idle_interval 159Date: January 2016 160Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 161Description: Controls the idle timing of system, if there is no FS operation 162 during given interval. 163 Set to 5 seconds by default. 164 165What: /sys/fs/f2fs/<disk>/discard_idle_interval 166Date: September 2018 167Contact: "Chao Yu" <yuchao0@huawei.com> 168Contact: "Sahitya Tummala" <stummala@codeaurora.org> 169Description: Controls the idle timing of discard thread given 170 this time interval. 171 Default is 5 secs. 172 173What: /sys/fs/f2fs/<disk>/gc_idle_interval 174Date: September 2018 175Contact: "Chao Yu" <yuchao0@huawei.com> 176Contact: "Sahitya Tummala" <stummala@codeaurora.org> 177Description: Controls the idle timing for gc path. Set to 5 seconds by default. 178 179What: /sys/fs/f2fs/<disk>/iostat_enable 180Date: August 2017 181Contact: "Chao Yu" <yuchao0@huawei.com> 182Description: Controls to enable/disable IO stat. 183 184What: /sys/fs/f2fs/<disk>/ra_nid_pages 185Date: October 2015 186Contact: "Chao Yu" <chao2.yu@samsung.com> 187Description: Controls the count of nid pages to be readaheaded. 188 When building free nids, F2FS reads NAT blocks ahead for 189 speed up. Default is 0. 190 191What: /sys/fs/f2fs/<disk>/dirty_nats_ratio 192Date: January 2016 193Contact: "Chao Yu" <chao2.yu@samsung.com> 194Description: Controls dirty nat entries ratio threshold, if current 195 ratio exceeds configured threshold, checkpoint will 196 be triggered for flushing dirty nat entries. 197 198What: /sys/fs/f2fs/<disk>/lifetime_write_kbytes 199Date: January 2016 200Contact: "Shuoran Liu" <liushuoran@huawei.com> 201Description: Shows total written kbytes issued to disk. 202 203What: /sys/fs/f2fs/<disk>/features 204Date: July 2017 205Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 206Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/ 207 Shows all enabled features in current device. 208 Supported features: 209 encryption, blkzoned, extra_attr, projquota, inode_checksum, 210 flexible_inline_xattr, quota_ino, inode_crtime, lost_found, 211 verity, sb_checksum, casefold, readonly, compression, pin_file. 212 213What: /sys/fs/f2fs/<disk>/feature_list/ 214Date: June 2021 215Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 216Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule. 217 Supported on-disk features: 218 encryption, block_zoned (aka blkzoned), extra_attr, 219 project_quota (aka projquota), inode_checksum, 220 flexible_inline_xattr, quota_ino, inode_crtime, lost_found, 221 verity, sb_checksum, casefold, readonly, compression. 222 Note that, pin_file is moved into /sys/fs/f2fs/features/. 223 224What: /sys/fs/f2fs/features/ 225Date: July 2017 226Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 227Description: Shows all enabled kernel features. 228 Supported features: 229 encryption, block_zoned, extra_attr, project_quota, 230 inode_checksum, flexible_inline_xattr, quota_ino, 231 inode_crtime, lost_found, verity, sb_checksum, 232 casefold, readonly, compression, test_dummy_encryption_v2, 233 atomic_write, pin_file, encrypted_casefold. 234 235What: /sys/fs/f2fs/<disk>/inject_rate 236Date: May 2016 237Contact: "Sheng Yong" <shengyong1@huawei.com> 238Description: Controls the injection rate of arbitrary faults. 239 240What: /sys/fs/f2fs/<disk>/inject_type 241Date: May 2016 242Contact: "Sheng Yong" <shengyong1@huawei.com> 243Description: Controls the injection type of arbitrary faults. 244 245What: /sys/fs/f2fs/<disk>/dirty_segments 246Date: October 2017 247Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 248Description: Shows the number of dirty segments. 249 250What: /sys/fs/f2fs/<disk>/reserved_blocks 251Date: June 2017 252Contact: "Chao Yu" <yuchao0@huawei.com> 253Description: Controls target reserved blocks in system, the threshold 254 is soft, it could exceed current available user space. 255 256What: /sys/fs/f2fs/<disk>/current_reserved_blocks 257Date: October 2017 258Contact: "Yunlong Song" <yunlong.song@huawei.com> 259Contact: "Chao Yu" <yuchao0@huawei.com> 260Description: Shows current reserved blocks in system, it may be temporarily 261 smaller than target_reserved_blocks, but will gradually 262 increase to target_reserved_blocks when more free blocks are 263 freed by user later. 264 265What: /sys/fs/f2fs/<disk>/gc_urgent 266Date: August 2017 267Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 268Description: Do background GC aggressively when set. When gc_urgent = 1, 269 background thread starts to do GC by given gc_urgent_sleep_time 270 interval. When gc_urgent = 2, F2FS will lower the bar of 271 checking idle in order to process outstanding discard commands 272 and GC a little bit aggressively. It is set to 0 by default. 273 274What: /sys/fs/f2fs/<disk>/gc_urgent_sleep_time 275Date: August 2017 276Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 277Description: Controls sleep time of GC urgent mode. Set to 500ms by default. 278 279What: /sys/fs/f2fs/<disk>/readdir_ra 280Date: November 2017 281Contact: "Sheng Yong" <shengyong1@huawei.com> 282Description: Controls readahead inode block in readdir. Enabled by default. 283 284What: /sys/fs/f2fs/<disk>/gc_pin_file_thresh 285Date: January 2018 286Contact: Jaegeuk Kim <jaegeuk@kernel.org> 287Description: This indicates how many GC can be failed for the pinned 288 file. If it exceeds this, F2FS doesn't guarantee its pinning 289 state. 2048 trials is set by default. 290 291What: /sys/fs/f2fs/<disk>/extension_list 292Date: Feburary 2018 293Contact: "Chao Yu" <yuchao0@huawei.com> 294Description: Used to control configure extension list: 295 - Query: cat /sys/fs/f2fs/<disk>/extension_list 296 - Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list 297 - Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list 298 - [h] means add/del hot file extension 299 - [c] means add/del cold file extension 300 301What: /sys/fs/f2fs/<disk>/unusable 302Date April 2019 303Contact: "Daniel Rosenberg" <drosen@google.com> 304Description: If checkpoint=disable, it displays the number of blocks that 305 are unusable. 306 If checkpoint=enable it displays the number of blocks that 307 would be unusable if checkpoint=disable were to be set. 308 309What: /sys/fs/f2fs/<disk>/encoding 310Date July 2019 311Contact: "Daniel Rosenberg" <drosen@google.com> 312Description: Displays name and version of the encoding set for the filesystem. 313 If no encoding is set, displays (none) 314 315What: /sys/fs/f2fs/<disk>/free_segments 316Date: September 2019 317Contact: "Hridya Valsaraju" <hridya@google.com> 318Description: Number of free segments in disk. 319 320What: /sys/fs/f2fs/<disk>/cp_foreground_calls 321Date: September 2019 322Contact: "Hridya Valsaraju" <hridya@google.com> 323Description: Number of checkpoint operations performed on demand. Available when 324 CONFIG_F2FS_STAT_FS=y. 325 326What: /sys/fs/f2fs/<disk>/cp_background_calls 327Date: September 2019 328Contact: "Hridya Valsaraju" <hridya@google.com> 329Description: Number of checkpoint operations performed in the background to 330 free segments. Available when CONFIG_F2FS_STAT_FS=y. 331 332What: /sys/fs/f2fs/<disk>/gc_foreground_calls 333Date: September 2019 334Contact: "Hridya Valsaraju" <hridya@google.com> 335Description: Number of garbage collection operations performed on demand. 336 Available when CONFIG_F2FS_STAT_FS=y. 337 338What: /sys/fs/f2fs/<disk>/gc_background_calls 339Date: September 2019 340Contact: "Hridya Valsaraju" <hridya@google.com> 341Description: Number of garbage collection operations triggered in background. 342 Available when CONFIG_F2FS_STAT_FS=y. 343 344What: /sys/fs/f2fs/<disk>/moved_blocks_foreground 345Date: September 2019 346Contact: "Hridya Valsaraju" <hridya@google.com> 347Description: Number of blocks moved by garbage collection in foreground. 348 Available when CONFIG_F2FS_STAT_FS=y. 349 350What: /sys/fs/f2fs/<disk>/moved_blocks_background 351Date: September 2019 352Contact: "Hridya Valsaraju" <hridya@google.com> 353Description: Number of blocks moved by garbage collection in background. 354 Available when CONFIG_F2FS_STAT_FS=y. 355 356What: /sys/fs/f2fs/<disk>/avg_vblocks 357Date: September 2019 358Contact: "Hridya Valsaraju" <hridya@google.com> 359Description: Average number of valid blocks. 360 Available when CONFIG_F2FS_STAT_FS=y. 361 362What: /sys/fs/f2fs/<disk>/mounted_time_sec 363Date: February 2020 364Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 365Description: Show the mounted time in secs of this partition. 366 367What: /sys/fs/f2fs/<disk>/data_io_flag 368Date: April 2020 369Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 370Description: Give a way to attach REQ_META|FUA to data writes 371 given temperature-based bits. Now the bits indicate: 372 373 +-------------------+-------------------+ 374 | REQ_META | REQ_FUA | 375 +------+------+-----+------+------+-----+ 376 | 5 | 4 | 3 | 2 | 1 | 0 | 377 +------+------+-----+------+------+-----+ 378 | Cold | Warm | Hot | Cold | Warm | Hot | 379 +------+------+-----+------+------+-----+ 380 381What: /sys/fs/f2fs/<disk>/node_io_flag 382Date: June 2020 383Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 384Description: Give a way to attach REQ_META|FUA to node writes 385 given temperature-based bits. Now the bits indicate: 386 387 +-------------------+-------------------+ 388 | REQ_META | REQ_FUA | 389 +------+------+-----+------+------+-----+ 390 | 5 | 4 | 3 | 2 | 1 | 0 | 391 +------+------+-----+------+------+-----+ 392 | Cold | Warm | Hot | Cold | Warm | Hot | 393 +------+------+-----+------+------+-----+ 394 395What: /sys/fs/f2fs/<disk>/iostat_period_ms 396Date: April 2020 397Contact: "Daeho Jeong" <daehojeong@google.com> 398Description: Give a way to change iostat_period time. 3secs by default. 399 The new iostat trace gives stats gap given the period. 400What: /sys/fs/f2fs/<disk>/max_io_bytes 401Date: December 2020 402Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 403Description: This gives a control to limit the bio size in f2fs. 404 Default is zero, which will follow underlying block layer limit, 405 whereas, if it has a certain bytes value, f2fs won't submit a 406 bio larger than that size. 407 408What: /sys/fs/f2fs/<disk>/stat/sb_status 409Date: December 2020 410Contact: "Chao Yu" <yuchao0@huawei.com> 411Description: Show status of f2fs superblock in real time. 412 413 ====== ===================== ================================= 414 value sb status macro description 415 0x1 SBI_IS_DIRTY dirty flag for checkpoint 416 0x2 SBI_IS_CLOSE specify unmounting 417 0x4 SBI_NEED_FSCK need fsck.f2fs to fix 418 0x8 SBI_POR_DOING recovery is doing or not 419 0x10 SBI_NEED_SB_WRITE need to recover superblock 420 0x20 SBI_NEED_CP need to checkpoint 421 0x40 SBI_IS_SHUTDOWN shutdown by ioctl 422 0x80 SBI_IS_RECOVERED recovered orphan/data 423 0x100 SBI_CP_DISABLED CP was disabled last mount 424 0x200 SBI_CP_DISABLED_QUICK CP was disabled quickly 425 0x400 SBI_QUOTA_NEED_FLUSH need to flush quota info in CP 426 0x800 SBI_QUOTA_SKIP_FLUSH skip flushing quota in current CP 427 0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted 428 0x2000 SBI_IS_RESIZEFS resizefs is in process 429 ====== ===================== ================================= 430 431What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio 432Date: January 2021 433Contact: "Daeho Jeong" <daehojeong@google.com> 434Description: Give a way to change checkpoint merge daemon's io priority. 435 Its default value is "be,3", which means "BE" I/O class and 436 I/O priority "3". We can select the class between "rt" and "be", 437 and set the I/O priority within valid range of it. "," delimiter 438 is necessary in between I/O class and priority number. 439 440What: /sys/fs/f2fs/<disk>/ovp_segments 441Date: March 2021 442Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> 443Description: Shows the number of overprovision segments. 444 445What: /sys/fs/f2fs/<disk>/compr_written_block 446Date: March 2021 447Contact: "Daeho Jeong" <daehojeong@google.com> 448Description: Show the block count written after compression since mount. Note 449 that when the compressed blocks are deleted, this count doesn't 450 decrease. If you write "0" here, you can initialize 451 compr_written_block and compr_saved_block to "0". 452 453What: /sys/fs/f2fs/<disk>/compr_saved_block 454Date: March 2021 455Contact: "Daeho Jeong" <daehojeong@google.com> 456Description: Show the saved block count with compression since mount. Note 457 that when the compressed blocks are deleted, this count doesn't 458 decrease. If you write "0" here, you can initialize 459 compr_written_block and compr_saved_block to "0". 460 461What: /sys/fs/f2fs/<disk>/compr_new_inode 462Date: March 2021 463Contact: "Daeho Jeong" <daehojeong@google.com> 464Description: Show the count of inode newly enabled for compression since mount. 465 Note that when the compression is disabled for the files, this count 466 doesn't decrease. If you write "0" here, you can initialize 467 compr_new_inode to "0". 468 469What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio 470Date: May 2021 471Contact: "Chao Yu" <yuchao0@huawei.com> 472Description: When ATGC is on, it controls candidate ratio in order to limit total 473 number of potential victim in all candidates, the value should be in 474 range of [0, 100], by default it was initialized as 20(%). 475 476What: /sys/fs/f2fs/<disk>/atgc_candidate_count 477Date: May 2021 478Contact: "Chao Yu" <yuchao0@huawei.com> 479Description: When ATGC is on, it controls candidate count in order to limit total 480 number of potential victim in all candidates, by default it was 481 initialized as 10 (sections). 482 483What: /sys/fs/f2fs/<disk>/atgc_age_weight 484Date: May 2021 485Contact: "Chao Yu" <yuchao0@huawei.com> 486Description: When ATGC is on, it controls age weight to balance weight proportion 487 in between aging and valid blocks, the value should be in range of 488 [0, 100], by default it was initialized as 60(%). 489 490What: /sys/fs/f2fs/<disk>/atgc_age_threshold 491Date: May 2021 492Contact: "Chao Yu" <yuchao0@huawei.com> 493Description: When ATGC is on, it controls age threshold to bypass GCing young 494 candidates whose age is not beyond the threshold, by default it was 495 initialized as 604800 seconds (equals to 7 days). 496