diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-fs-f2fs')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-fs-f2fs | 473 |
1 files changed, 436 insertions, 37 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 2416b03ff283..770470e0598b 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -49,15 +49,23 @@ Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> Description: Controls the in-place-update policy. updates in f2fs. User can set: - ==== ================= - 0x01 F2FS_IPU_FORCE - 0x02 F2FS_IPU_SSR - 0x04 F2FS_IPU_UTIL - 0x08 F2FS_IPU_SSR_UTIL - 0x10 F2FS_IPU_FSYNC - 0x20 F2FS_IPU_ASYNC, - 0x40 F2FS_IPU_NOCACHE - ==== ================= + ===== =============== =================================================== + value policy description + 0x00 DISABLE disable IPU(=default option in LFS mode) + 0x01 FORCE all the time + 0x02 SSR if SSR mode is activated + 0x04 UTIL if FS utilization is over threshold + 0x08 SSR_UTIL if SSR mode is activated and FS utilization is over + threshold + 0x10 FSYNC activated in fsync path only for high performance + flash storages. IPU will be triggered only if the + # of dirty pages over min_fsync_blocks. + (=default option) + 0x20 ASYNC do IPU given by asynchronous write requests + 0x40 NOCACHE disable IPU bio cache + 0x80 HONOR_OPU_WRITE use OPU write prior to IPU write if inode has + FI_OPU_WRITE flag + ===== =============== =================================================== Refer segment.h for details. @@ -94,9 +102,42 @@ What: /sys/fs/f2fs/<disk>/max_small_discards Date: November 2013 Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com> Description: Controls the issue rate of discard commands that consist of small - blocks less than 2MB. The candidates to be discarded are cached until - checkpoint is triggered, and issued during the checkpoint. - By default, it is disabled with 0. + blocks less than 2MB. The candidates to be discarded are cached during + checkpoint, and issued by issue_discard thread after checkpoint. + It is enabled by default. + +What: /sys/fs/f2fs/<disk>/max_ordered_discard +Date: October 2022 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: Controls the maximum ordered discard, the unit size is one block(4KB). + Set it to 16 by default. + +What: /sys/fs/f2fs/<disk>/max_discard_request +Date: December 2021 +Contact: "Konstantin Vyshetsky" <vkon@google.com> +Description: Controls the number of discards a thread will issue at a time. + Higher number will allow the discard thread to finish its work + faster, at the cost of higher latency for incoming I/O. + +What: /sys/fs/f2fs/<disk>/min_discard_issue_time +Date: December 2021 +Contact: "Konstantin Vyshetsky" <vkon@google.com> +Description: Controls the interval the discard thread will wait between + issuing discard requests when there are discards to be issued and + no I/O aware interruptions occur. + +What: /sys/fs/f2fs/<disk>/mid_discard_issue_time +Date: December 2021 +Contact: "Konstantin Vyshetsky" <vkon@google.com> +Description: Controls the interval the discard thread will wait between + issuing discard requests when there are discards to be issued and + an I/O aware interruption occurs. + +What: /sys/fs/f2fs/<disk>/max_discard_issue_time +Date: December 2021 +Contact: "Konstantin Vyshetsky" <vkon@google.com> +Description: Controls the interval the discard thread will wait when there are + no discard operations to be issued. What: /sys/fs/f2fs/<disk>/discard_granularity Date: July 2017 @@ -104,7 +145,8 @@ Contact: "Chao Yu" <yuchao0@huawei.com> Description: Controls discard granularity of inner discard thread. Inner thread will not issue discards with size that is smaller than granularity. The unit size is one block(4KB), now only support configuring - in range of [1, 512]. Default value is 4(=16KB). + in range of [1, 512]. Default value is 16. + For small devices, default value is 1. What: /sys/fs/f2fs/<disk>/umount_discard_timeout Date: January 2019 @@ -148,12 +190,6 @@ Description: Controls the memory footprint used by free nids and cached nat entries. By default, 1 is set, which indicates 10 MB / 1 GB RAM. -What: /sys/fs/f2fs/<disk>/batched_trim_sections -Date: February 2015 -Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> -Description: Controls the trimming rate in batch mode. - <deprecated> - What: /sys/fs/f2fs/<disk>/cp_interval Date: October 2015 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> @@ -169,7 +205,7 @@ Description: Controls the idle timing of system, if there is no FS operation What: /sys/fs/f2fs/<disk>/discard_idle_interval Date: September 2018 Contact: "Chao Yu" <yuchao0@huawei.com> -Contact: "Sahitya Tummala" <stummala@codeaurora.org> +Contact: "Sahitya Tummala" <quic_stummala@quicinc.com> Description: Controls the idle timing of discard thread given this time interval. Default is 5 secs. @@ -177,7 +213,7 @@ Description: Controls the idle timing of discard thread given What: /sys/fs/f2fs/<disk>/gc_idle_interval Date: September 2018 Contact: "Chao Yu" <yuchao0@huawei.com> -Contact: "Sahitya Tummala" <stummala@codeaurora.org> +Contact: "Sahitya Tummala" <quic_stummala@quicinc.com> Description: Controls the idle timing for gc path. Set to 5 seconds by default. What: /sys/fs/f2fs/<disk>/iostat_enable @@ -207,7 +243,7 @@ Description: Shows total written kbytes issued to disk. What: /sys/fs/f2fs/<disk>/features Date: July 2017 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> -Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/ +Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/> Shows all enabled features in current device. Supported features: encryption, blkzoned, extra_attr, projquota, inode_checksum, @@ -234,7 +270,7 @@ Description: Shows all enabled kernel features. 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. + atomic_write, pin_file, encrypted_casefold, linear_lookup. What: /sys/fs/f2fs/<disk>/inject_rate Date: May 2016 @@ -269,11 +305,19 @@ Description: Shows current reserved blocks in system, it may be temporarily What: /sys/fs/f2fs/<disk>/gc_urgent Date: August 2017 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> -Description: Do background GC aggressively when set. When gc_urgent = 1, - background thread starts to do GC by given gc_urgent_sleep_time - interval. When gc_urgent = 2, F2FS will lower the bar of - checking idle in order to process outstanding discard commands - and GC a little bit aggressively. It is set to 0 by default. +Description: Do background GC aggressively when set. Set to 0 by default. + gc urgent high(1): does GC forcibly in a period of given + gc_urgent_sleep_time and ignores I/O idling check. uses greedy + GC approach and turns SSR mode on. + gc urgent low(2): lowers the bar of checking I/O idling in + order to process outstanding discard commands and GC a + little bit aggressively. 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/<disk>/gc_urgent_sleep_time Date: August 2017 @@ -290,10 +334,10 @@ Date: January 2018 Contact: Jaegeuk Kim <jaegeuk@kernel.org> 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. + state. 2048 trials is set by default, and 65535 as maximum. What: /sys/fs/f2fs/<disk>/extension_list -Date: Feburary 2018 +Date: February 2018 Contact: "Chao Yu" <yuchao0@huawei.com> Description: Used to control configure extension list: - Query: cat /sys/fs/f2fs/<disk>/extension_list @@ -303,7 +347,7 @@ Description: Used to control configure extension list: - [c] means add/del cold file extension What: /sys/fs/f2fs/<disk>/unusable -Date April 2019 +Date: April 2019 Contact: "Daniel Rosenberg" <drosen@google.com> Description: If checkpoint=disable, it displays the number of blocks that are unusable. @@ -311,7 +355,7 @@ Description: If checkpoint=disable, it displays the number of blocks that would be unusable if checkpoint=disable were to be set. What: /sys/fs/f2fs/<disk>/encoding -Date July 2019 +Date: July 2019 Contact: "Daniel Rosenberg" <drosen@google.com> Description: Displays name and version of the encoding set for the filesystem. If no encoding is set, displays (none) @@ -430,8 +474,48 @@ Description: Show status of f2fs superblock in real time. 0x800 SBI_QUOTA_SKIP_FLUSH skip flushing quota in current CP 0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted 0x2000 SBI_IS_RESIZEFS resizefs is in process + 0x4000 SBI_IS_FREEZING freefs is in process ====== ===================== ================================= +What: /sys/fs/f2fs/<disk>/stat/cp_status +Date: September 2022 +Contact: "Chao Yu" <chao.yu@oppo.com> +Description: Show status of f2fs checkpoint in real time. + + =============================== ============================== + cp flag value + CP_UMOUNT_FLAG 0x00000001 + CP_ORPHAN_PRESENT_FLAG 0x00000002 + CP_COMPACT_SUM_FLAG 0x00000004 + CP_ERROR_FLAG 0x00000008 + CP_FSCK_FLAG 0x00000010 + CP_FASTBOOT_FLAG 0x00000020 + CP_CRC_RECOVERY_FLAG 0x00000040 + CP_NAT_BITS_FLAG 0x00000080 + CP_TRIMMED_FLAG 0x00000100 + CP_NOCRC_RECOVERY_FLAG 0x00000200 + CP_LARGE_NAT_BITMAP_FLAG 0x00000400 + CP_QUOTA_NEED_FSCK_FLAG 0x00000800 + CP_DISABLED_FLAG 0x00001000 + CP_DISABLED_QUICK_FLAG 0x00002000 + CP_RESIZEFS_FLAG 0x00004000 + =============================== ============================== + +What: /sys/fs/f2fs/<disk>/stat/issued_discard +Date: December 2023 +Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com> +Description: Shows the number of issued discard. + +What: /sys/fs/f2fs/<disk>/stat/queued_discard +Date: December 2023 +Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com> +Description: Shows the number of queued discard. + +What: /sys/fs/f2fs/<disk>/stat/undiscard_blks +Date: December 2023 +Contact: "Zhiguo Niu" <zhiguo.niu@unisoc.com> +Description: Shows the total number of undiscard blocks. + What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio Date: January 2021 Contact: "Daeho Jeong" <daehojeong@google.com> @@ -498,12 +582,18 @@ Description: When ATGC is on, it controls age threshold to bypass GCing young candidates whose age is not beyond the threshold, by default it was initialized as 604800 seconds (equals to 7 days). +What: /sys/fs/f2fs/<disk>/atgc_enabled +Date: Feb 2024 +Contact: "Jinbao Liu" <liujinbao1@xiaomi.com> +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/<disk>/gc_reclaimed_segments Date: July 2021 Contact: "Daeho Jeong" <daehojeong@google.com> Description: Show how many segments have been reclaimed by GC during a specific GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy, - 3: GC idle AT, 4: GC urgent high, 5: GC urgent low) + 3: GC idle AT, 4: GC urgent high, 5: GC urgent low 6: GC urgent mid) You can re-initialize this value to "0". What: /sys/fs/f2fs/<disk>/gc_segment_mode @@ -534,9 +624,318 @@ Description: With "mode=fragment:block" mount options, we can scatter block allo in the length of 1..<max_fragment_hole> by turns. This value can be set between 1..512 and the default value is 4. -What: /sys/fs/f2fs/<disk>/gc_urgent_high_remaining -Date: December 2021 -Contact: "Daeho Jeong" <daehojeong@google.com> -Description: You can set the trial count limit for GC urgent high mode with this value. +What: /sys/fs/f2fs/<disk>/gc_remaining_trials +Date: October 2022 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: You can set the trial count limit for GC urgent and idle mode with this value. If GC thread gets to the limit, the mode will turn back to GC normal mode. By default, the value is zero, which means there is no limit like before. + +What: /sys/fs/f2fs/<disk>/max_roll_forward_node_blocks +Date: January 2022 +Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> +Description: Controls max # of node block writes to be used for roll forward + recovery. This can limit the roll forward recovery time. + +What: /sys/fs/f2fs/<disk>/unusable_blocks_per_sec +Date: June 2022 +Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> +Description: Shows the number of unusable blocks in a section which was defined by + the zone capacity reported by underlying zoned device. + +What: /sys/fs/f2fs/<disk>/max_open_zones +Date: November 2025 +Contact: "Yongpeng Yang" <yangyongpeng@xiaomi.com> +Description: Shows the max number of zones that F2FS can write concurrently when a zoned + device is mounted. + +What: /sys/fs/f2fs/<disk>/current_atomic_write +Date: July 2022 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Show the total current atomic write block count, which is not committed yet. + This is a read-only entry. + +What: /sys/fs/f2fs/<disk>/peak_atomic_write +Date: July 2022 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Show the peak value of total current atomic write block count after boot. + If you write "0" here, you can initialize to "0". + +What: /sys/fs/f2fs/<disk>/committed_atomic_block +Date: July 2022 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Show the accumulated total committed atomic write block count after boot. + If you write "0" here, you can initialize to "0". + +What: /sys/fs/f2fs/<disk>/revoked_atomic_block +Date: July 2022 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Show the accumulated total revoked atomic write block count after boot. + If you write "0" here, you can initialize to "0". + +What: /sys/fs/f2fs/<disk>/gc_mode +Date: October 2022 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: Show the current gc_mode as a string. + This is a read-only entry. + +What: /sys/fs/f2fs/<disk>/discard_urgent_util +Date: November 2022 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: When space utilization exceeds this, do background DISCARD aggressively. + Does DISCARD forcibly in a period of given min_discard_issue_time when the number + of discards is not 0 and set discard granularity to 1. + Default: 80 + +What: /sys/fs/f2fs/<disk>/hot_data_age_threshold +Date: November 2022 +Contact: "Ping Xiong" <xiongping1@xiaomi.com> +Description: When DATA SEPARATION is on, it controls the age threshold to indicate + the data blocks as hot. By default it was initialized as 262144 blocks + (equals to 1GB). + +What: /sys/fs/f2fs/<disk>/warm_data_age_threshold +Date: November 2022 +Contact: "Ping Xiong" <xiongping1@xiaomi.com> +Description: When DATA SEPARATION is on, it controls the age threshold to indicate + the data blocks as warm. By default it was initialized as 2621440 blocks + (equals to 10GB). + +What: /sys/fs/f2fs/<disk>/fault_rate +Date: May 2016 +Contact: "Sheng Yong" <shengyong@oppo.com> +Contact: "Chao Yu" <chao@kernel.org> +Description: Enable fault injection in all supported types with + specified injection rate. + +What: /sys/fs/f2fs/<disk>/fault_type +Date: May 2016 +Contact: "Sheng Yong" <shengyong@oppo.com> +Contact: "Chao Yu" <chao@kernel.org> +Description: Support configuring fault injection type, should be + enabled with fault_injection option, fault type value + is shown below, it supports single or combined type. + + =========================== ========== + Type_Name Type_Value + =========================== ========== + FAULT_KMALLOC 0x00000001 + FAULT_KVMALLOC 0x00000002 + FAULT_PAGE_ALLOC 0x00000004 + FAULT_PAGE_GET 0x00000008 + FAULT_ALLOC_BIO 0x00000010 (obsolete) + FAULT_ALLOC_NID 0x00000020 + FAULT_ORPHAN 0x00000040 + FAULT_BLOCK 0x00000080 + FAULT_DIR_DEPTH 0x00000100 + FAULT_EVICT_INODE 0x00000200 + FAULT_TRUNCATE 0x00000400 + FAULT_READ_IO 0x00000800 + FAULT_CHECKPOINT 0x00001000 + FAULT_DISCARD 0x00002000 + FAULT_WRITE_IO 0x00004000 + FAULT_SLAB_ALLOC 0x00008000 + FAULT_DQUOT_INIT 0x00010000 + FAULT_LOCK_OP 0x00020000 + FAULT_BLKADDR_VALIDITY 0x00040000 + FAULT_BLKADDR_CONSISTENCE 0x00080000 + FAULT_NO_SEGMENT 0x00100000 + FAULT_INCONSISTENT_FOOTER 0x00200000 + FAULT_TIMEOUT 0x00400000 (1000ms) + FAULT_VMALLOC 0x00800000 + =========================== ========== + +What: /sys/fs/f2fs/<disk>/discard_io_aware_gran +Date: January 2023 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: Controls background discard granularity of inner discard thread + when is not in idle. Inner thread will not issue discards with size that + is smaller than granularity. The unit size is one block(4KB), now only + support configuring in range of [0, 512]. + Default: 512 + +What: /sys/fs/f2fs/<disk>/last_age_weight +Date: January 2023 +Contact: "Ping Xiong" <xiongping1@xiaomi.com> +Description: When DATA SEPARATION is on, it controls the weight of last data block age. + +What: /sys/fs/f2fs/<disk>/compress_watermark +Date: February 2023 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: When compress cache is on, it controls free memory watermark + in order to limit caching compress page. If free memory is lower + than watermark, then deny caching compress page. The value should be in + range of (0, 100], by default it was initialized as 20(%). + +What: /sys/fs/f2fs/<disk>/compress_percent +Date: February 2023 +Contact: "Yangtao Li" <frank.li@vivo.com> +Description: When compress cache is on, it controls cached page + percent(compress pages / free_ram) in order to limit caching compress page. + If cached page percent exceed threshold, then deny caching compress page. + The value should be in range of (0, 100], by default it was initialized + as 20(%). + +What: /sys/fs/f2fs/<disk>/discard_io_aware +Date: November 2023 +Contact: "Chao Yu" <chao@kernel.org> +Description: It controls to enable/disable IO aware feature for background discard. + By default, the value is 1 which indicates IO aware is on. + +What: /sys/fs/f2fs/<disk>/blkzone_alloc_policy +Date: July 2024 +Contact: "Yuanhong Liao" <liaoyuanhong@vivo.com> +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/<disk>/migration_window_granularity +Date: September 2024 +Contact: "Daeho Jeong" <daehojeong@google.com> +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/<disk>/reserved_segments +Date: September 2024 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: In order to fine tune GC behavior, we can control the number of + reserved segments. + +What: /sys/fs/f2fs/<disk>/gc_no_zoned_gc_percent +Date: September 2024 +Contact: "Daeho Jeong" <daehojeong@google.com> +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/<disk>/gc_boost_zoned_gc_percent +Date: September 2024 +Contact: "Daeho Jeong" <daehojeong@google.com> +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/<disk>/gc_valid_thresh_ratio +Date: September 2024 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: It controls the valid block ratio threshold not to trigger excessive GC + for zoned devices. The initial value of it is 95(%). F2FS will stop the + background GC thread from initiating GC for sections having valid blocks + exceeding the ratio. + +What: /sys/fs/f2fs/<disk>/max_read_extent_count +Date: November 2024 +Contact: "Chao Yu" <chao@kernel.org> +Description: It controls max read extent count for per-inode, the value of threshold + is 10240 by default. + +What: /sys/fs/f2fs/tuning/reclaim_caches_kb +Date: February 2025 +Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> +Description: It reclaims the given KBs of file-backed pages registered by + ioctl(F2FS_IOC_DONATE_RANGE). + For example, writing N tries to drop N KBs spaces in LRU. + +What: /sys/fs/f2fs/<disk>/carve_out +Date: March 2025 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: For several zoned storage devices, vendors will provide extra space which + was used for device level GC than specs and F2FS can use this space for + filesystem level GC. To do that, we can reserve the space using + reserved_blocks. However, it is not enough, since this extra space should + not be shown to users. So, with this new sysfs node, we can hide the space + by subtracting reserved_blocks from total bytes. + +What: /sys/fs/f2fs/<disk>/encoding_flags +Date: April 2025 +Contact: "Chao Yu" <chao@kernel.org> +Description: This is a read-only entry to show the value of sb.s_encoding_flags, the + value is hexadecimal. + + ============================ ========== + Flag_Name Flag_Value + ============================ ========== + SB_ENC_STRICT_MODE_FL 0x00000001 + SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002 + ============================ ========== + +What: /sys/fs/f2fs/<disk>/reserved_pin_section +Date: June 2025 +Contact: "Chao Yu" <chao@kernel.org> +Description: This threshold is used to control triggering garbage collection while + fallocating on pinned file, so, it can guarantee there is enough free + reserved section before preallocating on pinned file. + By default, the value is ovp_sections, especially, for zoned ufs, the + value is 1. + +What: /sys/fs/f2fs/<disk>/gc_boost_gc_multiple +Date: June 2025 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Set a multiplier for the background GC migration window when F2FS GC is + boosted. The range should be from 1 to the segment count in a section. + Default: 5 + +What: /sys/fs/f2fs/<disk>/gc_boost_gc_greedy +Date: June 2025 +Contact: "Daeho Jeong" <daehojeong@google.com> +Description: Control GC algorithm for boost GC. 0: cost benefit, 1: greedy + Default: 1 + +What: /sys/fs/f2fs/<disk>/effective_lookup_mode +Date: August 2025 +Contact: "Daniel Lee" <chullee@google.com> +Description: + This is a read-only entry to show the effective directory lookup mode + F2FS is currently using for casefolded directories. + This considers both the "lookup_mode" mount option and the on-disk + encoding flag, SB_ENC_NO_COMPAT_FALLBACK_FL. + + Possible values are: + - "perf": Hash-only lookup. + - "compat": Hash-based lookup with a linear search fallback enabled + - "auto:perf": lookup_mode is auto and fallback is disabled on-disk + - "auto:compat": lookup_mode is auto and fallback is enabled on-disk + +What: /sys/fs/f2fs/<disk>/bggc_io_aware +Date: August 2025 +Contact: "Liao Yuanhong" <liaoyuanhong@vivo.com> +Description: Used to adjust the BG_GC priority when pending IO, with a default value + of 0. Specifically, for ZUFS, the default value is 1. + + ================== ====================================================== + value description + bggc_io_aware = 0 skip background GC if there is any kind of pending IO + bggc_io_aware = 1 skip background GC if there is pending read IO + bggc_io_aware = 2 don't aware IO for background GC + ================== ====================================================== + +What: /sys/fs/f2fs/<disk>/allocate_section_hint +Date: August 2025 +Contact: "Liao Yuanhong" <liaoyuanhong@vivo.com> +Description: Indicates the hint section between the first device and others in multi-devices + setup. It defaults to the end of the first device in sections. For a single storage + device, it defaults to the total number of sections. It can be manually set to match + scenarios where multi-devices are mapped to the same dm device. + +What: /sys/fs/f2fs/<disk>/allocate_section_policy +Date: August 2025 +Contact: "Liao Yuanhong" <liaoyuanhong@vivo.com> +Description: Controls write priority in multi-devices setups. A value of 0 means normal writing. + A value of 1 prioritizes writing to devices before the allocate_section_hint. A value of 2 + prioritizes writing to devices after the allocate_section_hint. The default is 0. + + =========================== ========================================================== + value description + allocate_section_policy = 0 Normal writing + allocate_section_policy = 1 Prioritize writing to section before allocate_section_hint + allocate_section_policy = 2 Prioritize writing to section after allocate_section_hint + =========================== ========================================================== |