Documentation/ABI/testing/sysfs-fs-f2fs
Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-fs-f2fs
File Facts
- System
- Linux kernel
- Corpus path
Documentation/ABI/testing/sysfs-fs-f2fs- Extension
[no extension]- Size
- 41966 bytes
- Lines
- 1004
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: Documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
Date: July 2013
Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description: Controls the maximum sleep time for gc_thread. Time
is in milliseconds.
What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
Date: July 2013
Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description: Controls the minimum sleep time for gc_thread. Time
is in milliseconds.
What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
Date: July 2013
Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description: Controls the default sleep time for gc_thread. Time
is in milliseconds.
What: /sys/fs/f2fs/<disk>/gc_idle
Date: July 2013
Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
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/<disk>/reclaim_segments
Date: October 2013
Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
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/<disk>/main_blkaddr
Date: November 2019
Contact: "Ramon Pantin" <pantin@google.com>
Description: Shows first block address of MAIN area.
What: /sys/fs/f2fs/<disk>/ipu_policy
Date: November 2013
Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
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.
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.