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Diffstat (limited to 'Documentation/filesystems/f2fs.txt')
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 84 |
1 files changed, 78 insertions, 6 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index bd3c56c67380..3cd27bed6349 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -18,8 +18,8 @@ according to its internal geometry or flash memory management scheme, namely FTL F2FS and its tools support various parameters not only for configuring on-disk layout, but also for selecting allocation and cleaning algorithms. -The file system formatting tool, "mkfs.f2fs", is available from the following -git tree: +The following git tree provides the file system formatting tool (mkfs.f2fs), +a consistency checking tool (fsck.f2fs), and a debugging tool (dump.f2fs). >> git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git For reporting bugs and sending patches, please use the following mailing list: @@ -98,8 +98,13 @@ Cleaning Overhead MOUNT OPTIONS ================================================================================ -background_gc_off Turn off cleaning operations, namely garbage collection, - triggered in background when I/O subsystem is idle. +background_gc=%s Turn on/off cleaning operations, namely garbage + collection, triggered in background when I/O subsystem is + idle. If background_gc=on, it will turn on the garbage + collection and if background_gc=off, garbage collection + will be truned off. + Default value for this option is on. So garbage + collection is on by default. disable_roll_forward Disable the roll-forward recovery routine discard Issue discard/TRIM commands when a segment is cleaned. no_heap Disable heap-style segment allocation which finds free @@ -128,6 +133,38 @@ f2fs. Each file shows the whole f2fs information. - current memory footprint consumed by f2fs. ================================================================================ +SYSFS ENTRIES +================================================================================ + +Information about mounted f2f2 file systems can be found in +/sys/fs/f2fs. Each mounted filesystem will have a directory in +/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda). +The files in each per-device directory are shown in table below. + +Files in /sys/fs/f2fs/<devname> +(see also Documentation/ABI/testing/sysfs-fs-f2fs) +.............................................................................. + File Content + + gc_max_sleep_time This tuning parameter controls the maximum sleep + time for the garbage collection thread. Time is + in milliseconds. + + gc_min_sleep_time This tuning parameter controls the minimum sleep + time for the garbage collection thread. Time is + in milliseconds. + + gc_no_gc_sleep_time This tuning parameter controls the default sleep + time for the garbage collection thread. Time is + in milliseconds. + + gc_idle This parameter controls the selection of victim + 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 aproach. + +================================================================================ USAGE ================================================================================ @@ -144,8 +181,12 @@ USAGE # mkfs.f2fs -l label /dev/block_device # mount -t f2fs /dev/block_device /mnt/f2fs -Format options --------------- +mkfs.f2fs +--------- +The mkfs.f2fs is for the use of formatting a partition as the f2fs filesystem, +which builds a basic on-disk layout. + +The options consist of: -l [label] : Give a volume label, up to 512 unicode name. -a [0 or 1] : Split start location of each area for heap-based allocation. 1 is set by default, which performs this. @@ -159,6 +200,37 @@ Format options -t [0 or 1] : Disable discard command or not. 1 is set by default, which conducts discard. +fsck.f2fs +--------- +The fsck.f2fs is a tool to check the consistency of an f2fs-formatted +partition, which examines whether the filesystem metadata and user-made data +are cross-referenced correctly or not. +Note that, initial version of the tool does not fix any inconsistency. + +The options consist of: + -d debug level [default:0] + +dump.f2fs +--------- +The dump.f2fs shows the information of specific inode and dumps SSA and SIT to +file. Each file is dump_ssa and dump_sit. + +The dump.f2fs is used to debug on-disk data structures of the f2fs filesystem. +It shows on-disk inode information reconized by a given inode number, and is +able to dump all the SSA and SIT entries into predefined files, ./dump_ssa and +./dump_sit respectively. + +The options consist of: + -d debug level [default:0] + -i inode no (hex) + -s [SIT dump segno from #1~#2 (decimal), for all 0~-1] + -a [SSA dump segno from #1~#2 (decimal), for all 0~-1] + +Examples: +# dump.f2fs -i [ino] /dev/sdx +# dump.f2fs -s 0~-1 /dev/sdx (SIT dump) +# dump.f2fs -a 0~-1 /dev/sdx (SSA dump) + ================================================================================ DESIGN ================================================================================ |