Merge tag 'kvm-s390-next-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-2.6.git] / Documentation / ABI / testing / sysfs-fs-f2fs
index aedeae1e8ec180f699f32a7f05b6b6b81105372c..1a6cd539712928f8f75bb04e340540bddc2c9300 100644 (file)
@@ -1,37 +1,40 @@
 What:          /sys/fs/f2fs/<disk>/gc_max_sleep_time
 Date:          July 2013
 Contact:       "Namjae Jeon" <namjae.jeon@samsung.com>
-Description:
-                Controls the maximun sleep time for gc_thread. Time
-                is in milliseconds.
+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.
+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.
+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.
+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.
 
 What:          /sys/fs/f2fs/<disk>/reclaim_segments
 Date:          October 2013
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the issue rate of segment discard commands.
-
-What:          /sys/fs/f2fs/<disk>/max_blkaddr
+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:
@@ -40,227 +43,278 @@ Description:
 What:          /sys/fs/f2fs/<disk>/ipu_policy
 Date:          November 2013
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the in-place-update policy.
+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.
+               Refer segment.h for details.
 
 What:          /sys/fs/f2fs/<disk>/min_ipu_util
 Date:          November 2013
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the FS utilization condition for the in-place-update
-                policies.
+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/<disk>/min_fsync_blocks
 Date:          September 2014
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Controls the dirty page count condition for the in-place-update
-                policies.
+Description:   Controls the dirty page count condition for the in-place-update
+               policies.
 
 What:          /sys/fs/f2fs/<disk>/min_seq_blocks
 Date:          August 2018
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Controls the dirty page count condition for batched sequential
-                writes in ->writepages.
-
+Description:   Controls the dirty page count condition for batched sequential
+               writes in writepages.
 
 What:          /sys/fs/f2fs/<disk>/min_hot_blocks
 Date:          March 2017
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Controls the dirty page count condition for redefining hot data.
+Description:   Controls the dirty page count condition for redefining hot data.
 
 What:          /sys/fs/f2fs/<disk>/min_ssr_sections
 Date:          October 2017
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-Description:
-                Controls the fee section threshold to trigger SSR allocation.
+Description:   Controls the free section threshold to trigger SSR allocation.
+               If this is large, SSR mode will be enabled early.
 
 What:          /sys/fs/f2fs/<disk>/max_small_discards
 Date:          November 2013
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the issue rate of small discard commands.
+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.
 
-What:          /sys/fs/f2fs/<disk>/discard_granularity
-Date:          July 2017
-Contact:       "Chao Yu" <yuchao0@huawei.com>
-Description:
-               Controls discard granularity of inner discard thread, inner thread
+What:          /sys/fs/f2fs/<disk>/discard_granularity
+Date:          July 2017
+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, now only support configuring in range
-               of [1, 512].
+               The unit size is one block(4KB), now only support configuring
+               in range of [1, 512]. Default value is 4(=16KB).
 
-What:          /sys/fs/f2fs/<disk>/umount_discard_timeout
-Date:          January 2019
-Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-               Set timeout to issue discard commands during umount.
-               Default: 5 secs
+What:          /sys/fs/f2fs/<disk>/umount_discard_timeout
+Date:          January 2019
+Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:   Set timeout to issue discard commands during umount.
+               Default: 5 secs
 
 What:          /sys/fs/f2fs/<disk>/max_victim_search
 Date:          January 2014
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the number of trials to find a victim segment.
+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/<disk>/migration_granularity
 Date:          October 2018
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-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.
+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/<disk>/dir_level
 Date:          March 2014
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the directory level for large directory.
+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/<disk>/ram_thresh
 Date:          March 2014
 Contact:       "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
-Description:
-                Controls the memory footprint used by f2fs.
+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>
+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>
-Description:
-                Controls the checkpoint timing.
+Description:   Controls the checkpoint timing, set to 60 seconds by default.
 
 What:          /sys/fs/f2fs/<disk>/idle_interval
 Date:          January 2016
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Controls the idle timing for all paths other than
-                discard and gc path.
+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/<disk>/discard_idle_interval
 Date:          September 2018
 Contact:       "Chao Yu" <yuchao0@huawei.com>
 Contact:       "Sahitya Tummala" <stummala@codeaurora.org>
-Description:
-                Controls the idle timing for discard path.
+Description:   Controls the idle timing of discard thread given
+               this time interval.
+               Default is 5 secs.
 
 What:          /sys/fs/f2fs/<disk>/gc_idle_interval
 Date:          September 2018
 Contact:       "Chao Yu" <yuchao0@huawei.com>
 Contact:       "Sahitya Tummala" <stummala@codeaurora.org>
-Description:
-                Controls the idle timing for gc path.
+Description:    Controls the idle timing for gc path. Set to 5 seconds by default.
 
 What:          /sys/fs/f2fs/<disk>/iostat_enable
 Date:          August 2017
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-Description:
-                Controls to enable/disable IO stat.
+Description:   Controls to enable/disable IO stat.
 
 What:          /sys/fs/f2fs/<disk>/ra_nid_pages
 Date:          October 2015
 Contact:       "Chao Yu" <chao2.yu@samsung.com>
-Description:
-                Controls the count of nid pages to be readaheaded.
+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/<disk>/dirty_nats_ratio
 Date:          January 2016
 Contact:       "Chao Yu" <chao2.yu@samsung.com>
-Description:
-                Controls dirty nat entries ratio threshold, if current
-                ratio exceeds configured threshold, checkpoint will
-                be triggered for flushing dirty nat entries.
+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/<disk>/lifetime_write_kbytes
 Date:          January 2016
 Contact:       "Shuoran Liu" <liushuoran@huawei.com>
-Description:
-                Shows total written kbytes issued to disk.
+Description:   Shows total written kbytes issued to disk.
 
 What:          /sys/fs/f2fs/<disk>/features
 Date:          July 2017
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Shows all enabled features in current device.
+Description:   Shows all enabled features in current device.
 
 What:          /sys/fs/f2fs/<disk>/inject_rate
 Date:          May 2016
 Contact:       "Sheng Yong" <shengyong1@huawei.com>
-Description:
-                Controls the injection rate.
+Description:   Controls the injection rate of arbitrary faults.
 
 What:          /sys/fs/f2fs/<disk>/inject_type
 Date:          May 2016
 Contact:       "Sheng Yong" <shengyong1@huawei.com>
-Description:
-                Controls the injection type.
+Description:   Controls the injection type of arbitrary faults.
+
+What:          /sys/fs/f2fs/<disk>/dirty_segments
+Date:          October 2017
+Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:   Shows the number of dirty segments.
 
 What:          /sys/fs/f2fs/<disk>/reserved_blocks
 Date:          June 2017
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-Description:
-                Controls target reserved blocks in system, the threshold
-                is soft, it could exceed current available user space.
+Description:   Controls target reserved blocks in system, the threshold
+               is soft, it could exceed current available user space.
 
 What:          /sys/fs/f2fs/<disk>/current_reserved_blocks
 Date:          October 2017
 Contact:       "Yunlong Song" <yunlong.song@huawei.com>
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-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.
+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/<disk>/gc_urgent
 Date:          August 2017
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Do background GC agressively
+Description:   Do background GC agressively when set. When gc_urgent = 1,
+               background thread starts to do GC by given gc_urgent_sleep_time
+               interval. It is set to 0 by default.
 
 What:          /sys/fs/f2fs/<disk>/gc_urgent_sleep_time
 Date:          August 2017
 Contact:       "Jaegeuk Kim" <jaegeuk@kernel.org>
-Description:
-                Controls sleep time of GC urgent mode
+Description:   Controls sleep time of GC urgent mode. Set to 500ms by default.
 
 What:          /sys/fs/f2fs/<disk>/readdir_ra
 Date:          November 2017
 Contact:       "Sheng Yong" <shengyong1@huawei.com>
-Description:
-                Controls readahead inode block in readdir.
+Description:   Controls readahead inode block in readdir. Enabled by default.
+
+What:          /sys/fs/f2fs/<disk>/gc_pin_file_thresh
+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.
 
 What:          /sys/fs/f2fs/<disk>/extension_list
 Date:          Feburary 2018
 Contact:       "Chao Yu" <yuchao0@huawei.com>
-Description:
-                Used to control configure extension list:
-                - Query: cat /sys/fs/f2fs/<disk>/extension_list
-                - Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
-                - Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
-                - [h] means add/del hot file extension
-                - [c] means add/del cold file extension
+Description:   Used to control configure extension list:
+               - Query: cat /sys/fs/f2fs/<disk>/extension_list
+               - Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
+               - Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
+               - [h] means add/del hot file extension
+               - [c] means add/del cold file extension
 
 What:          /sys/fs/f2fs/<disk>/unusable
 Date           April 2019
 Contact:       "Daniel Rosenberg" <drosen@google.com>
-Description:
-               If checkpoint=disable, it displays the number of blocks that are unusable.
-                If checkpoint=enable it displays the enumber of blocks that would be unusable
-                if checkpoint=disable were to be set.
+Description:   If checkpoint=disable, it displays the number of blocks that
+               are unusable.
+               If checkpoint=enable it displays the enumber of blocks that
+               would be unusable if checkpoint=disable were to be set.
 
 What:          /sys/fs/f2fs/<disk>/encoding
 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)
+Description:   Displays name and version of the encoding set for the filesystem.
+               If no encoding is set, displays (none)
+
+What:          /sys/fs/f2fs/<disk>/free_segments
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of free segments in disk.
+
+What:          /sys/fs/f2fs/<disk>/cp_foreground_calls
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of checkpoint operations performed on demand. Available when
+               CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/cp_background_calls
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of checkpoint operations performed in the background to
+               free segments. Available when CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/gc_foreground_calls
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of garbage collection operations performed on demand.
+               Available when CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/gc_background_calls
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of garbage collection operations triggered in background.
+               Available when CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/moved_blocks_foreground
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of blocks moved by garbage collection in foreground.
+               Available when CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/moved_blocks_background
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Number of blocks moved by garbage collection in background.
+               Available when CONFIG_F2FS_STAT_FS=y.
+
+What:          /sys/fs/f2fs/<disk>/avg_vblocks
+Date:          September 2019
+Contact:       "Hridya Valsaraju" <hridya@google.com>
+Description:   Average number of valid blocks.
+               Available when CONFIG_F2FS_STAT_FS=y.