What: /sys/fs/f2fs//gc_max_sleep_time Date: July 2013 Contact: "Namjae Jeon" Description: Controls the maximum sleep time for gc_thread. Time is in milliseconds. What: /sys/fs/f2fs//gc_min_sleep_time Date: July 2013 Contact: "Namjae Jeon" Description: Controls the minimum sleep time for gc_thread. Time is in milliseconds. What: /sys/fs/f2fs//gc_no_gc_sleep_time Date: July 2013 Contact: "Namjae Jeon" Description: Controls the default sleep time for gc_thread. Time is in milliseconds. What: /sys/fs/f2fs//gc_idle Date: July 2013 Contact: "Namjae Jeon" Description: Controls the victim selection policy for garbage collection. Setting gc_idle = 0(default) will disable this option. Setting: =========== =============================================== gc_idle = 1 will select the Cost Benefit approach & setting gc_idle = 2 will select the greedy approach & setting gc_idle = 3 will select the age-threshold based approach. =========== =============================================== What: /sys/fs/f2fs//reclaim_segments Date: October 2013 Contact: "Jaegeuk Kim" Description: This parameter controls the number of prefree segments to be reclaimed. If the number of prefree segments is larger than the number of segments in the proportion to the percentage over total volume size, f2fs tries to conduct checkpoint to reclaim the prefree segments to free segments. By default, 5% over total # of segments. What: /sys/fs/f2fs//main_blkaddr Date: November 2019 Contact: "Ramon Pantin" Description: Shows first block address of MAIN area. What: /sys/fs/f2fs//ipu_policy Date: November 2013 Contact: "Jaegeuk Kim" Description: Controls the in-place-update policy. updates in f2fs. User can set: ===== =============== =================================================== 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//min_ipu_util Date: November 2013 Contact: "Jaegeuk Kim" Description: Controls the FS utilization condition for the in-place-update policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies. What: /sys/fs/f2fs//min_fsync_blocks Date: September 2014 Contact: "Jaegeuk Kim" Description: Controls the dirty page count condition for the in-place-update policies. What: /sys/fs/f2fs//min_seq_blocks Date: August 2018 Contact: "Jaegeuk Kim" Description: Controls the dirty page count condition for batched sequential writes in writepages. What: /sys/fs/f2fs//min_hot_blocks Date: March 2017 Contact: "Jaegeuk Kim" Description: Controls the dirty page count condition for redefining hot data. What: /sys/fs/f2fs//min_ssr_sections Date: October 2017 Contact: "Chao Yu" Description: Controls the free section threshold to trigger SSR allocation. If this is large, SSR mode will be enabled early. What: /sys/fs/f2fs//max_small_discards Date: November 2013 Contact: "Jaegeuk Kim" Description: Controls the issue rate of discard commands that consist of small 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//max_ordered_discard Date: October 2022 Contact: "Yangtao Li" Description: Controls the maximum ordered discard, the unit size is one block(4KB). Set it to 16 by default. What: /sys/fs/f2fs//max_discard_request Date: December 2021 Contact: "Konstantin Vyshetsky" 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//min_discard_issue_time Date: December 2021 Contact: "Konstantin Vyshetsky" 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//mid_discard_issue_time Date: December 2021 Contact: "Konstantin Vyshetsky" 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//max_discard_issue_time Date: December 2021 Contact: "Konstantin Vyshetsky" Description: Controls the interval the discard thread will wait when there are no discard operations to be issued. What: /sys/fs/f2fs//discard_granularity Date: July 2017 Contact: "Chao Yu" 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 16. For small devices, default value is 1. What: /sys/fs/f2fs//umount_discard_timeout Date: January 2019 Contact: "Jaegeuk Kim" Description: Set timeout to issue discard commands during umount. Default: 5 secs What: /sys/fs/f2fs//pending_discard Date: November 2021 Contact: "Jaegeuk Kim" Description: Shows the number of pending discard commands in the queue. What: /sys/fs/f2fs//max_victim_search Date: January 2014 Contact: "Jaegeuk Kim" Description: Controls the number of trials to find a victim segment when conducting SSR and cleaning operations. The default value is 4096 which covers 8GB block address range. What: /sys/fs/f2fs//migration_granularity Date: October 2018 Contact: "Chao Yu" Description: Controls migration granularity of garbage collection on large section, it can let GC move partial segment{s} of one section in one GC cycle, so that dispersing heavy overhead GC to multiple lightweight one. What: /sys/fs/f2fs//dir_level Date: March 2014 Contact: "Jaegeuk Kim" Description: Controls the directory level for large directory. If a directory has a number of files, it can reduce the file lookup latency by increasing this dir_level value. Otherwise, it needs to decrease this value to reduce the space overhead. The default value is 0. What: /sys/fs/f2fs//ram_thresh Date: March 2014 Contact: "Jaegeuk Kim" 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//cp_interval Date: October 2015 Contact: "Jaegeuk Kim" Description: Controls the checkpoint timing, set to 60 seconds by default. What: /sys/fs/f2fs//idle_interval Date: January 2016 Contact: "Jaegeuk Kim" Description: Controls the idle timing of system, if there is no FS operation during given interval. Set to 5 seconds by default. What: /sys/fs/f2fs//discard_idle_interval Date: September 2018 Contact: "Chao Yu" Contact: "Sahitya Tummala" Description: Controls the idle timing of discard thread given this time interval. Default is 5 secs. What: /sys/fs/f2fs//gc_idle_interval Date: September 2018 Contact: "Chao Yu" Contact: "Sahitya Tummala" Description: Controls the idle timing for gc path. Set to 5 seconds by default. What: /sys/fs/f2fs//iostat_enable Date: August 2017 Contact: "Chao Yu" Description: Controls to enable/disable IO stat. What: /sys/fs/f2fs//ra_nid_pages Date: October 2015 Contact: "Chao Yu" Description: Controls the count of nid pages to be readaheaded. When building free nids, F2FS reads NAT blocks ahead for speed up. Default is 0. What: /sys/fs/f2fs//dirty_nats_ratio Date: January 2016 Contact: "Chao Yu" Description: Controls dirty nat entries ratio threshold, if current ratio exceeds configured threshold, checkpoint will be triggered for flushing dirty nat entries. What: /sys/fs/f2fs//lifetime_write_kbytes Date: January 2016 Contact: "Shuoran Liu" Description: Shows total written kbytes issued to disk. What: /sys/fs/f2fs//features Date: July 2017 Contact: "Jaegeuk Kim" Description: /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//feature_list/ Date: June 2021 Contact: "Jaegeuk Kim" Description: Expand /sys/fs/f2fs//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" 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//inject_rate Date: May 2016 Contact: "Sheng Yong" Description: Controls the injection rate of arbitrary faults. What: /sys/fs/f2fs//inject_type Date: May 2016 Contact: "Sheng Yong" Description: Controls the injection type of arbitrary faults. What: /sys/fs/f2fs//dirty_segments Date: October 2017 Contact: "Jaegeuk Kim" Description: Shows the number of dirty segments. What: /sys/fs/f2fs//reserved_blocks Date: June 2017 Contact: "Chao Yu" Description: Controls target reserved blocks in system, the threshold is soft, it could exceed current available user space. What: /sys/fs/f2fs//current_reserved_blocks Date: October 2017 Contact: "Yunlong Song" Contact: "Chao Yu" Description: Shows current reserved blocks in system, it may be temporarily smaller than target_reserved_blocks, but will gradually increase to target_reserved_blocks when more free blocks are freed by user later. What: /sys/fs/f2fs//gc_urgent Date: August 2017 Contact: "Jaegeuk Kim" 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. always uses cost benefit GC approach, and will override age-threshold GC approach if ATGC is enabled at the same time. 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. always uses cost benefit GC approach, and will override age-threshold GC approach if ATGC is enabled at the same time. What: /sys/fs/f2fs//gc_urgent_sleep_time Date: August 2017 Contact: "Jaegeuk Kim" Description: Controls sleep time of GC urgent mode. Set to 500ms by default. What: /sys/fs/f2fs//readdir_ra Date: November 2017 Contact: "Sheng Yong" Description: Controls readahead inode block in readdir. Enabled by default. What: /sys/fs/f2fs//gc_pin_file_thresh Date: January 2018 Contact: Jaegeuk Kim Description: This indicates how many GC can be failed for the pinned file. If it exceeds this, F2FS doesn't guarantee its pinning state. 2048 trials is set by default, and 65535 as maximum. What: /sys/fs/f2fs//extension_list Date: February 2018 Contact: "Chao Yu" Description: Used to control configure extension list: - Query: cat /sys/fs/f2fs//extension_list - Add: echo '[h/c]extension' > /sys/fs/f2fs//extension_list - Del: echo '[h/c]!extension' > /sys/fs/f2fs//extension_list - [h] means add/del hot file extension - [c] means add/del cold file extension What: /sys/fs/f2fs//unusable Date April 2019 Contact: "Daniel Rosenberg" Description: If checkpoint=disable, it displays the number of blocks that are unusable. If checkpoint=enable it displays the number of blocks that would be unusable if checkpoint=disable were to be set. What: /sys/fs/f2fs//encoding Date July 2019 Contact: "Daniel Rosenberg" Description: Displays name and version of the encoding set for the filesystem. If no encoding is set, displays (none) What: /sys/fs/f2fs//free_segments Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of free segments in disk. What: /sys/fs/f2fs//cp_foreground_calls Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of checkpoint operations performed on demand. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//cp_background_calls Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of checkpoint operations performed in the background to free segments. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//gc_foreground_calls Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of garbage collection operations performed on demand. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//gc_background_calls Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of garbage collection operations triggered in background. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//moved_blocks_foreground Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of blocks moved by garbage collection in foreground. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//moved_blocks_background Date: September 2019 Contact: "Hridya Valsaraju" Description: Number of blocks moved by garbage collection in background. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//avg_vblocks Date: September 2019 Contact: "Hridya Valsaraju" Description: Average number of valid blocks. Available when CONFIG_F2FS_STAT_FS=y. What: /sys/fs/f2fs//mounted_time_sec Date: February 2020 Contact: "Jaegeuk Kim" Description: Show the mounted time in secs of this partition. What: /sys/fs/f2fs//data_io_flag Date: April 2020 Contact: "Jaegeuk Kim" Description: Give a way to attach REQ_META|FUA to data writes given temperature-based bits. Now the bits indicate: +-------------------+-------------------+ | REQ_META | REQ_FUA | +------+------+-----+------+------+-----+ | 5 | 4 | 3 | 2 | 1 | 0 | +------+------+-----+------+------+-----+ | Cold | Warm | Hot | Cold | Warm | Hot | +------+------+-----+------+------+-----+ What: /sys/fs/f2fs//node_io_flag Date: June 2020 Contact: "Jaegeuk Kim" Description: Give a way to attach REQ_META|FUA to node writes given temperature-based bits. Now the bits indicate: +-------------------+-------------------+ | REQ_META | REQ_FUA | +------+------+-----+------+------+-----+ | 5 | 4 | 3 | 2 | 1 | 0 | +------+------+-----+------+------+-----+ | Cold | Warm | Hot | Cold | Warm | Hot | +------+------+-----+------+------+-----+ What: /sys/fs/f2fs//iostat_period_ms Date: April 2020 Contact: "Daeho Jeong" 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//max_io_bytes Date: December 2020 Contact: "Jaegeuk Kim" 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//stat/sb_status Date: December 2020 Contact: "Chao Yu" 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//stat/cp_status Date: September 2022 Contact: "Chao Yu" 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//stat/issued_discard Date: December 2023 Contact: "Zhiguo Niu" Description: Shows the number of issued discard. What: /sys/fs/f2fs//stat/queued_discard Date: December 2023 Contact: "Zhiguo Niu" Description: Shows the number of queued discard. What: /sys/fs/f2fs//stat/undiscard_blks Date: December 2023 Contact: "Zhiguo Niu" Description: Shows the total number of undiscard blocks. What: /sys/fs/f2fs//ckpt_thread_ioprio Date: January 2021 Contact: "Daeho Jeong" 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//ovp_segments Date: March 2021 Contact: "Jaegeuk Kim" Description: Shows the number of overprovision segments. What: /sys/fs/f2fs//compr_written_block Date: March 2021 Contact: "Daeho Jeong" 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//compr_saved_block Date: March 2021 Contact: "Daeho Jeong" 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//compr_new_inode Date: March 2021 Contact: "Daeho Jeong" 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//atgc_candidate_ratio Date: May 2021 Contact: "Chao Yu" 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//atgc_candidate_count Date: May 2021 Contact: "Chao Yu" 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//atgc_age_weight Date: May 2021 Contact: "Chao Yu" 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//atgc_age_threshold Date: May 2021 Contact: "Chao Yu" 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//atgc_enabled Date: Feb 2024 Contact: "Jinbao Liu" Description: It represents whether ATGC is on or off. The value is 1 which indicates that ATGC is on, and 0 indicates that it is off. What: /sys/fs/f2fs//gc_reclaimed_segments Date: July 2021 Contact: "Daeho Jeong" 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//gc_segment_mode Date: July 2021 Contact: "Daeho Jeong" 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//seq_file_ra_mul Date: July 2021 Contact: "Daeho Jeong" 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//max_fragment_chunk Date: August 2021 Contact: "Daeho Jeong" Description: With "mode=fragment:block" mount options, we can scatter block allocation. f2fs will allocate 1.. blocks in a chunk and make a hole in the length of 1.. by turns. This value can be set between 1..512 and the default value is 4. What: /sys/fs/f2fs//max_fragment_hole Date: August 2021 Contact: "Daeho Jeong" Description: With "mode=fragment:block" mount options, we can scatter block allocation. f2fs will allocate 1.. blocks in a chunk and make a hole in the length of 1.. by turns. This value can be set between 1..512 and the default value is 4. What: /sys/fs/f2fs//gc_remaining_trials Date: October 2022 Contact: "Yangtao Li" 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//max_roll_forward_node_blocks Date: January 2022 Contact: "Jaegeuk Kim" 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//unusable_blocks_per_sec Date: June 2022 Contact: "Jaegeuk Kim" 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//current_atomic_write Date: July 2022 Contact: "Daeho Jeong" Description: Show the total current atomic write block count, which is not committed yet. This is a read-only entry. What: /sys/fs/f2fs//peak_atomic_write Date: July 2022 Contact: "Daeho Jeong" 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//committed_atomic_block Date: July 2022 Contact: "Daeho Jeong" 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//revoked_atomic_block Date: July 2022 Contact: "Daeho Jeong" 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//gc_mode Date: October 2022 Contact: "Yangtao Li" Description: Show the current gc_mode as a string. This is a read-only entry. What: /sys/fs/f2fs//discard_urgent_util Date: November 2022 Contact: "Yangtao Li" 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//hot_data_age_threshold Date: November 2022 Contact: "Ping Xiong" 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//warm_data_age_threshold Date: November 2022 Contact: "Ping Xiong" 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//fault_rate Date: May 2016 Contact: "Sheng Yong" Contact: "Chao Yu" Description: Enable fault injection in all supported types with specified injection rate. What: /sys/fs/f2fs//fault_type Date: May 2016 Contact: "Sheng Yong" Contact: "Chao Yu" 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//discard_io_aware_gran Date: January 2023 Contact: "Yangtao Li" 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//last_age_weight Date: January 2023 Contact: "Ping Xiong" Description: When DATA SEPARATION is on, it controls the weight of last data block age. What: /sys/fs/f2fs//compress_watermark Date: February 2023 Contact: "Yangtao Li" 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//compress_percent Date: February 2023 Contact: "Yangtao Li" 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//discard_io_aware Date: November 2023 Contact: "Chao Yu" Description: It controls to enable/disable IO aware feature for background discard. By default, the value is 1 which indicates IO aware is on. What: /sys/fs/f2fs//blkzone_alloc_policy Date: July 2024 Contact: "Yuanhong Liao" Description: The zone UFS we are currently using consists of two parts: conventional zones and sequential zones. It can be used to control which part to prioritize for writes, with a default value of 0. ======================== ========================================= value description blkzone_alloc_policy = 0 Prioritize writing to sequential zones blkzone_alloc_policy = 1 Only allow writing to sequential zones blkzone_alloc_policy = 2 Prioritize writing to conventional zones ======================== ========================================= What: /sys/fs/f2fs//migration_window_granularity Date: September 2024 Contact: "Daeho Jeong" Description: Controls migration window granularity of garbage collection on large section. it can control the scanning window granularity for GC migration in a unit of segment, while migration_granularity controls the number of segments which can be migrated at the same turn. What: /sys/fs/f2fs//reserved_segments Date: September 2024 Contact: "Daeho Jeong" Description: In order to fine tune GC behavior, we can control the number of reserved segments. What: /sys/fs/f2fs//gc_no_zoned_gc_percent Date: September 2024 Contact: "Daeho Jeong" Description: If the percentage of free sections over total sections is above this number, F2FS do not garbage collection for zoned devices through the background GC thread. the default number is "60". What: /sys/fs/f2fs//gc_boost_zoned_gc_percent Date: September 2024 Contact: "Daeho Jeong" Description: If the percentage of free sections over total sections is under this number, F2FS boosts garbage collection for zoned devices through the background GC thread. the default number is "25". What: /sys/fs/f2fs//gc_valid_thresh_ratio Date: September 2024 Contact: "Daeho Jeong" Description: It controls the valid block ratio threshold not to trigger excessive GC for zoned deivces. The initial value of it is 95(%). F2FS will stop the background GC thread from intiating GC for sections having valid blocks exceeding the ratio. What: /sys/fs/f2fs//max_read_extent_count Date: November 2024 Contact: "Chao Yu" Description: It controls max read extent count for per-inode, the value of threshold is 10240 by default.