I have a f2fs partition with missing Superblock. I made a disk image so I would not destroy the original partition trying to fix. sd-repair# fsck.f2fs sd128.img Info: Segments per section = 1 Info: Sections per zone = 1 Info: sector size = 512 Info: total sectors = 249737216 (121942 MB) Can't find a valid F2FS superblock at 0x0 Can't find a valid F2FS superblock at 0x1 Testdisk doesn't support F2FS. I don't know if there is a way to rewrite the superblocks, I would like to recover my files or repair the filesystem. Here is hex of what I believe is F2FS superblock, from a good partition 10 20 F5 F2 01 00 07 00 09 00 00 00 03 00 00 00 0C 00 00 00 09 00 00 00 01 00 00 00 01 00 00 00 00 00 00 00 00 00 20 00 00 00 00 00 E1 0F 00 00 FF 0F 00 00 02 00 00 00 02 00 00 00 12 00 00 00 08 00 00 00 E1 0F 00 00 00 02 00 00 00 02 00 00 00 06 00 00 00 0A 00 00 00 2E 00 00 00 3E 00 00 03 00 00 00 01 00 00 00 02 00 00 00 31 8B E4 FB 13 D1 42 26 A5 07 EA 8A B6 70 A9 45 Here is the hex I found on bad partiton 10 20 F5 F2 01 00 07 00 09 00 00 00 03 00 00 00 0C 00 00 00 09 00 00 00 01 00 00 00 01 00 00 00 00 00 00 00 00 46 DC 01 00 00 00 00 31 ED 00 00 22 EE 00 00 02 00 00 00 06 00 00 00 72 00 00 00 77 00 00 00 31 ED 00 00 00 02 00 00 00 02 00 00 00 06 00 00 00 12 00 00 00 F6 00 00 00 E4 01 00 03 00 00 00 01 00 00 00 02 00 00 00 16 CD C2 62 53 10 46 17 A5 B7 41 C6 8E AA 33 D5 73 00 64 00 2D 00 65 00 78 00 74 00 The superblock seems ok, differences are because of 1 is 128 GB part and other is 8 GB part. I don't know how to tell if the superblock is in the right location on bad partition. There offset don't match, from what I can tell. But I'm not that good with hex editors so I don't know how to compare there offsets. Update: the offset for the superblock was wrong it was at 0x600 or 3 sector. I removed the first 512 bytes from the disk image. Now fsck.f2fs shows sd-repair# fsck.f2fs -f trim_sd.img Info: Force to fix corruption Info: Segments per section = 1 Info: Sections per zone = 1 Info: sector size = 512 Info: total sectors = 249704447 (121925 MB) Info: MKFS version "Linux version 3.4.0-CM-g87d27dd (Adam@TheKeurig) (gcc version 4.9 20150123 (prerelease) (GCC) ) #6 SMP PREEMPT Sat Dec 17 21:28:57 CET 2016" Info: FSCK version from "Linux version 4.9.0-3-amd64 (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2 (2017-06-12)" to "Linux version 4.9.0-3-amd64 (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2 (2017-06-12)" Info: superblock features = 0 : Info: superblock encrypt level = 0, salt = 00000000000000000000000000000000 Info: total FS sectors = 249704448 (121926 MB) [f2fs_crc_valid: 477] CRC validation failed: cal_crc = 4076150800, blk_crc = 0 buff_size = 0x0 [f2fs_crc_valid: 477] CRC validation failed: cal_crc = 4076150800, blk_crc = 0 buff_size = 0x0 [f2fs_do_mount:1945] Can't find valid checkpoint From what I can tell the partition has shifted, It might be on issue with partition table. All the data seems to be intact. Is is using ms-dos partition table.

I've been trying to get a "clean" f2fs format on a WD SSD drive. But there is something that bugs me, and I cannot seem to find any specific details on it. When I format the SSD with f2fs: ```none $ sudo mkfs.f2fs -f -d9 -l BlueSSD /dev/sdb1 F2FS-tools: mkfs.f2fs Ver: 1.15.0 (2022-05-13) Info: Disable heap-based policy Info: Debug level = 9 Info: Label = BlueSSD Info: Trim is enabled Info: [/dev/sdb1] Disk Model: NCE0010PNC /dev/sdb1 appears to contain an existing filesystem (f2fs). Info: Segments per section = 1 Info: Sections per zone = 1 Info: sector size = 512 Info: total sectors = 1953521664 (953868 MB) Info: zone aligned segment0 blkaddr: 512 Info: format version with "Linux version 6.12.20+rpt-rpi-v8 (serge@raspberrypi.com) (aarch64-linux-gnu-gcc-12 (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #1 SMP PREEMPT Debian 1:6.12.20-1+rpt1~bpo12+1 (2025-03-19)" Info: [/dev/sdb1] Discarding device Info: This device doesn't support BLKSECDISCARD # This device doesn't support BLKDISCARD This device doesn't support BLKSECDISCARD I found that with both error messages, fstrim would fail. The SSD is connected to my system via USB-SATA adapter cable, so I figured I might need a udev rule. I [found one here](https://glump.net/howto/desktop/enable-trim-on-an-external-ssd-on-linux) that took care of the BLKDISCARD error; i.e. fstrim now runs successfully on the drive. However it did nothing for the BLKSECDISCARD error. [This search](https://duckduckgo.com/?q=what+does+%22BLKSECDISCARD%22+mean&t=ffab&df=2020-04-02..2025-04-03&ia=web) turned up results that suggest this is related to some sort of "security vulnerability" - maybe secure erase/wipe?? The same warning appears in several online posts related to formatting SSDs with mkfs.f2fs, but I've found no discussion or explanation of its meaning. And if it's actually a vulnerability, maybe I should be glad that it's ***not supported*** :) ?? So, a couple of questions for the *cognoscenti*: 1. What is the BLKSECDISCARD message; what does it mean, what are its implications? 2. Is there a patch available that makes it "go away"?

I used the Debian 12.5.0 ISO DVD image from the official website and wrote it to a USB flash drive via Rufus. During the "Load installer components from installation media" process got stuck, and by switching to the command line via CTRL+ALT+Fn, I could look at the Log and found that it triggered a Kernel Bug, is there any relevant clues? Edited: I've tried many times and the problem occurs at different steps of the installation, but the error remains the same and 95% of the time it occurs at the "Load installer components from installation media" step. There are two paragraphs in the Log, the first of which is:

[   20.009517] WARNING: CPU: 0 PID: 876 at mm/shmem.c:1193 shmem_evict_inode+0x26e/0x2b0
[   20.009521] Modules linked in: storage_ssd_mod intel_spi_cr_platform fat isofs hid_generic usbhid hid ...
[   20.009523] CPU: 0 PID: 876 Comm: kworker/u8:1 Not tainted 6.1.0-10-amd64 #1 Debian 6.1.76-1
[   20.009524] Hardware name: ASUSTeK COMPUTER INC. System Product Name/Pro WS W680-ACE IPMI, BIOS 3501 04/19/2024
[   20.009525] RIP: 0010:shmem_evict_inode+0x26e/0x2b0

The second is:

[ 20.009567] kernel BUG at fs/inode.c:613!
[ 20.009568] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 20.009569] CPU: 0 PID: 876 Comm: debconf Tainted: G W 6.1.0-18-amd64 #1 Debian 6.1.76-1
[ 20.009571] Hardware name: ASUSTeK COMPUTER INC. System Product Name/Pro WS W680-ACE IPMI, BIOS 3501 04/12/2024
[ 20.009572] RIP: 0010:clear_inode+0x7z/0x80

See image for details:

I read that the f2fs format is good for SSD storage so I formatted one of my drives with it. I also read in some kernel notes that encryption was added for it but there's no documentation to speak of. I typically prefer whole disk encryption. I'm not sure if that's possible for f2fs. I'm wondering if anyone knows any steps in which I might be able to encrypt an f2fs drive. I know it's done on Android for their full drive encryption (I'm running Ubuntu). Is LUKS filesystem agnostic? I don't think so. Any encryption would be good. No docs == no good. Here's a reference of kernel updates: http://lkml.iu.edu/hypermail/linux/kernel/1506.3/00598.html

A f2fs partition on my Android phone has recently become corrupted. It will still mount fine; however, I completely lost access to one directory (/data/media/0 ), which now shows as empty. Yet the disk space hasn't changed at all. When running fsck.f2fs from the terminal, it refuses to check on a mounted filesystem. I cannot unmount the data partition or remount it as read-only. Fine. After rebooting under recovery mode, where the partition is not mounted, I get this when running fsck.f2fs: ~ # fsck.f2fs /dev/block/mmcblk0p39 Info: sector size = 512 Info: total sectors = 21425920 (in 512bytes) Assertion failed! [fsck_chk_dentry_blk: 563] le32_to_cpu(de_blk->dentry[i].hash_code) == hash_code So it still refuses to help me and it now fails with an obscure error… stating the directory gives me: root@victara:/ # stat /data/media/0 File: `/data/media/0' Size: 4096 Blocks: 24 IO Blocks: 4096 directory Device: 10307h/66311d Inode: 4 Links: 35 Access: (770/drwxrwx---) Uid: (1023/media_rw) Gid: (1023/media_rw) Access: 2016-04-04 16:55:56.800148001 Modify: 2016-04-05 02:47:44.314999998 Change: 2016-04-05 02:47:44.314999998 The inode (number?) seemed to be quite low… So I checked other directories: root@victara:/ # stat /data/media/ File: '/data/media/' Size: 4096 Blocks: 16 IO Block: 4096 directory Device: 10307h/66311d Inode: 4078 Links: 4 Access: (0770/drwxrwx---) Uid: ( 1023/media_rw) Gid: ( 1023/media_rw) __bionic_open_tzdata: couldn't find any tzdata when looking for localtime! __bionic_open_tzdata: couldn't find any tzdata when looking for GMT! __bionic_open_tzdata: couldn't find any tzdata when looking for posixrules! Access: 2016-04-04 14:48:25.000000000 Modify: 1970-01-01 02:27:21.000000000 Change: 1970-02-07 02:30:36.000000000 root@victara:/ # stat /data/media/obb File: `/data/media/obb' Size: 4096 Blocks: 16 IO Blocks: 4096 directory Device: 10307h/66311d Inode: 4080 Links: 3 Access: (775/drwxrwxr-x) Uid: (1023/media_rw) Gid: (1023/media_rw) Access: 1970-01-01 03:27:21.519999999 Modify: 2016-03-17 22:38:30.505748550 Change: 2016-04-04 17:42:31.569999988 It looks like the parent dir (/data/media) has inode 4078, another child of the parent (/data/media/obb) has inode 4080. So, logically, /data/media/0 should have inode 4079, but stat tells me it has inode 4. So it looks like the filesystem metadata got corrupted. Without help from fsck.f2fs and debugfs (which sadly doesn't exist for f2fs), and in a pretty minimal Linux environment (Android recovery), is there a way I can correct the inode number or something else I can do to recover access to my data? --- Interestingly, the directory still seems to be taking up disk space, and it is considered as "not empty" so I cannot remove it. root@victara:/data/media # rm -rf 0 rm: 0: Directory not empty 1|root@victara:/data/media # ls 0 obb root@victara:/data/media # ls -al 0 total 0 *IMPORTANT: I cannot test solutions anymore since I need the phone and the storage space and reformatted the partition.*

I have a ramdisk mounted to /ram which typically holds temporary data that I know don't need saved. The filesystem of the ramdisk is f2fs, created by zram-generator with this configuration:

# /etc/systemd/zram-generator.conf
[zram0]
zram-size = ram
fs-type = f2fs
compression-algorithm = zstd
mount-point = /ram
options = nosuid,nodev,noatime,X-mount.mode=1777,X-mount.group=ramuser,atgc,gc_merge,lazytime

It will mount with these options:

$ findmnt /ram
TARGET SOURCE     FSTYPE OPTIONS
/ram   /dev/zram0 f2fs   rw,nosuid,nodev,noatime,lazytime,background_gc=on,gc_merge,discard,discard_unit=block,user_xattr,inline_xattr,acl,inline_data,inline_dentry,flush_merge,barrier,extent_cache,mode=adaptive,active_logs=6,alloc_mode=default,checkpoint_merge,fsync_mode=posix,atgc,memory=normal,errors=continue

This works for all my purposes as I intend. (Typically, I have a lot of text files which benefit greatly from the compression.) Now, I have a few video files which I want to convert to another format. I don't need them on my disk and I am fine with them being lost after a power outage, so I have them only in memory. For the conversion, I have this for loop:

for i in *.mkv; do
   ffmpeg -i "${i}" "${i:r}.mp4"  # convert mkv to mp4
   rm -v "${i}"                   # remove original
done

(The ffmpeg command is abbreviated, it works.) There are 6 mkv files which are 2 GB each, so it occupies 12 GB. This is fine. The converted mp4s are roughly the same size, so during the loop, it should use at maximum 12+2 GB. The -v switch for rm shows the removal of the file after the conversion. However, the memory fills up and the system breaks at some point. When killing the loop (with Ctrl+c), the memory is finally freed. So, it does not purge the old mkv files until the loop has finished. Does this for i in *.mkv hold all files, so that they can't be removed and are purged only after the loop has finished? lsof does not show the old files being still accessed. The file is removed (ls doesn't show it) but it seems like it's not purged.

I have got an encrypted f2fs image, I know the password, I'm able to mount it via sudo mount -t f2fs mmcblk0p64.img /mnt/mmcblk0p64 so it doesn't appear broken or anything, and f2fscrypt recognizes the policy

f2fscrypt get_policy /mnt/mmcblk0p64/data                                     
/mnt/mmcblk0p64/data: 17532673d8ab1f9f

however

fsck.f2fs -f mmcblk0p64.img
Info: Force to fix corruption
Info: MKFS version
  "4.9.206-perf+"
Info: FSCK version
  from "4.9.206-perf+"
    to "Linux version 6.5.7-060507-generic (kernel@sita) (x86_64-linux-gnu-gcc-13 (Ubuntu 13.2.0-4ubuntu3) 13.2.0, GNU ld (GNU Binutils for Ubuntu) 2.41) #202310102154 SMP PREEMPT_DYNAMIC Tue Oct 10 22:00:30 UTC 2023"
Info: superblock features = 481 :  encrypt verity quota_ino
Info: superblock encrypt level = 0, salt = 1a9ecca697dd4d1b9eb0d41a55754d41
Info: Segments per section = 1
Info: Sections per zone = 1
Info: total FS sectors = 104939480 (51239 MB)
Info: CKPT version = 9d277d6
Info: checkpoint state = 44 :  crc compacted_summary sudden-power-off

prints this salt, and when trying to use it to add a key like this:

f2fscrypt add_key -S 1a9ecca697dd4d1b9eb0d41a55754d41
Invalid salt: 1a9ecca697dd4d1b9eb0d41a55754d41

it fails. Is this the wrong salt, where do I get the salt for this purpose? The img comes from a broken android device, running kernel 4.9.206-perf+ f2fs-tools version f2fs-tools/mantic,now 1.16.0-1 Using twrp is not an option, it fails to decrypt it via the shell and the screen is broken. I need to be able to decrypt it on my computer.

I'm trying to use quota option in the f2fs filesystem. I have created a filesystem with f2fs and have a mounting point. I have added quota mounting options in /etc/fstab and remounted my device(sd card) and checked with the following command:

/proc/mounts | grep ' /mnt/xyz '

I cant see updated quota options in device mounting options. my linux kernel is v5.11 and I found that quota option is available from linux kernel v5.14(https://www.ansymbol.com/linux/v5.14/ident/quota_ino ). >quotacheck: Mountpoint (or device) /media/venk/UserData not found or has no quota enabled. >quotacheck: Cannot find filesystem to check or filesystem not mounted with quota option. any solutions, please?

A day ago, my SSD was perfectly usable. Then it suddenly corrupted my home filesystem, resulting in the following fsck output at the most verbose debugging level:

Info: Fix the reported corruption.
Info: Force to fix corruption
Info: Force to fix corruption
Info: Debug level = 3
	Info: can't find /sys, assuming normal block device
Info: Segments per section = 1
Info: Sections per zone = 1
Info: sector size = 512
Info: total sectors = 536870912 (262144 MB)
Info: MKFS version
  "Linux version 5.4.0-72-generic (buildd@lcy01-amd64-019) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #80-Ubuntu SMP Mon Apr 12 17:35:00 UTC 2021"
Info: FSCK version
  from "Linux version 5.4.0-74-generic (buildd@lgw01-amd64-038) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #83-Ubuntu SMP Sat May 8 02:35:39 UTC 2021"
    to "Linux version 6.2.0-20-generic (buildd@lcy02-amd64-035) (x86_64-linux-gnu-gcc-12 (Ubuntu 12.2.0-17ubuntu1) 12.2.0, GNU ld (GNU Binutils for Ubuntu) 2.40) #20-Ubuntu SMP PREEMPT_DYNAMIC Thu Apr  6 07:48:48 UTC 2023"
Info: superblock features = 0 : 
Info: superblock encrypt level = 0, salt = 00000000000000000000000000000000

+--------------------------------------------------------+
| Super block                                            |
+--------------------------------------------------------+
magic                         		[0xf2f52010 : 4076150800]
major_ver                     		[0x       1 : 1]
volum_name                    		[]
minor_ver                     		[0x       b : 11]
log_sectorsize                		[0x       9 : 9]
log_sectors_per_block         		[0x       3 : 3]
log_blocksize                 		[0x       c : 12]
log_blocks_per_seg            		[0x       9 : 9]
segs_per_sec                  		[0x       1 : 1]
secs_per_zone                 		[0x       1 : 1]
checksum_offset               		[0x       0 : 0]
block_count                   		[0x 4000000 : 67108864]
section_count                 		[0x   1fe85 : 130693]
segment_count                 		[0x   1ffff : 131071]
segment_count_ckpt            		[0x       2 : 2]
segment_count_sit             		[0x       a : 10]
segment_count_nat             		[0x      6e : 110]
segment_count_ssa             		[0x     100 : 256]
segment_count_main            		[0x   1fe85 : 130693]
segment0_blkaddr              		[0x     200 : 512]
cp_blkaddr                    		[0x     200 : 512]
sit_blkaddr                   		[0x     600 : 1536]
nat_blkaddr                   		[0x    1a00 : 6656]
ssa_blkaddr                   		[0x    f600 : 62976]
main_blkaddr                  		[0x   2f600 : 194048]
root_ino                      		[0x       3 : 3]
node_ino                      		[0x       1 : 1]
meta_ino                      		[0x       2 : 2]
cp_payload                    		[0x       0 : 0]
crc                           		[0x       0 : 0]
version                       Linux version 5.4.0-74-generic (buildd@lgw01-amd64-038) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #83-Ubuntu SMP Sat May 8 02:35:39 UTC 2021
Info: total FS sectors = 536870912 (262144 MB)
	Invalid CP CRC offset: 0
	Invalid CP CRC offset: 0
[f2fs_do_mount:3512] Can't find valid checkpoint

What are my options to restore the filesystem to a working condition? I am willing to write code to restore the superblock and/or checkpoints, including to assemble a valid checkpoint out of existing invalid checkpoints and existing superblock. Other filesystems in the drive are fine.

I have downloaded the latest version of the fscrypt v0.3.1, and installed all the runtime dependencies as mentioned in the README of fscrypt. When running make command in the fscrypt source folder, the following error shows:

: error: ld returned 1 exit status

: *** [Makefile:96: bin/fscrypt] Error 2

How to change the filesystem label and UUID of a F2FS filesystem? For EXT filesystems tune2fs from e2fsprogs has the -L new_label and -U uuid command-line options, but none of the utilities installed by f2fs-tools 1.13.0 (latest version at the moment of writing) seem to have similar functionality.

According to this Seagate presentation there are some ongoing (?) efforts targeted toward modification of ext4 file system introducing SMRFS -EXT4 - support of hmHDD. The goal is to provide layer that will hide specifics of ZAC commands from applications (I believe). There is also this document that claims that "As of kernel v 4.7... hm drives are exposed as SG node - No block device file". What does it mean? maybe these document are outdated and ext4 (or other common linux file system) has been added support for host aware HDD. What linux distro support HMHDD by file system? If such support exists - What steps are needed to get HMHDD up and running without changes in applications (where file system hides all specifics)? General applications like DB are my concern - not log style. Also there is such video (SDC2020: Improve Distributed Storage System TCO with SMR HDDs) that claims that starting from 4.10 linux kernel f2fs supports drives already - did you used such approach? Maybe f2fs is not best match for random operations but I hope f2fs can fulfill such tasks with acceptable performance (where reading is dominant)

When creating a new Flash-Friendly Filesystem (f2fs) with mkfs.f2fs, there is a switch to turn on or off what is described as "heap-based allocation". The man page describes the switch as: > -a heap-based-allocation > > Specify 1 or 0 to enable/disable heap based block allocation policy. If the value is equal to 1, each of active log areas are initially assigned separately according to the whole volume size. The default value is 1. which, doesn't really specify what the feature does. Some searches suggest that this was changed from a default of on to a default of off (and suggested this was a "feature"), but there is very little I can find to describe what this option does and what the actual ramifications of having it on vs off are.

As far as I know it is possible to enable on new partition. Is there any way to enable compression on existing f2fs partition? I don't want to wipe and create a new partition to enable this feature.

I have f2fs partition formatted with -O extra_attrs,compression. I've applied chattr +c to / before installing Archlinux. du shows 6.4G used and df shows 6.5G used. Compression algorithm is set in the fstab. How do I check that files are compressed indeed?

The maximum volume size supported by the f2fs file system 16TiB. How is this value determined ?

In the man page of mkfs.f2fs, I see the option: > -O feature-list Specify a feature list in order f2fs filesystem will supports. e.g "encrypt" and so on I'd like to know how can I get the full list of the optional features of f2fs and whether it is possible to modify existing file system and enable some features without data loss.

As per my understanding, READ/WRITE etc are file system operations in linux. The file systems registers callbacks with the Kernel (VFS) and are in turn called by it when the particular FS is detected during a READ/WRITE operation. For example: **EXT4_write:** VFS write request -> ext4_writepages() **F2FS_write:** VFS write request -> f2fs_write_data_page() But what if the storage medium is not formatted. It does not have any file system. When a READ/WRITE operation is performed on it, which filesystem operation is selected by default ?

I'm running Arch Linux [testing] x86_64 For some reasons, I can't relabel my root file system (F2FS) with SELinux (custom kernel compiled, using refpolicy) Kernel ver $ uname -a ⏎ Linux PenArch 3.16.3.201409282025-1-grsec #1 ZEN SMP PREEMPT x86_64 GNU/Linux Chcon error: # chcon -t mozilla_exec_t /usr/lib/nightly/nightly chcon: failed to change context of ‘/usr/lib/nightly/nightly’ to ‘system_u:object_r:mozilla_exec_t’: Operation not supported Here is my config snippet: CONFIG_F2FS_FS=m CONFIG_F2FS_STAT_FS=y CONFIG_F2FS_FS_XATTR=y CONFIG_F2FS_FS_POSIX_ACL=y CONFIG_F2FS_FS_SECURITY=y CONFIG_F2FS_CHECK_FS=y CONFIG_SECURITY_SELINUX=y CONFIG_SECURITY_SELINUX_BOOTPARAM=y CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE=0 CONFIG_SECURITY_SELINUX_DISABLE=y CONFIG_SECURITY_SELINUX_DEVELOP=y CONFIG_SECURITY_SELINUX_AVC_STATS=y CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE=1 # CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX is not set CONFIG_DEFAULT_SECURITY_SELINUX=y

I installed the f2fs-tools package in my Fedora system. I created a f2fs partition using mkfs.f2fs on my sdcard, but now I'm unable to use it. The system is unable to mount automatically nor manually the partition. Does anyone have some insight in what I may be doing wrong or not doing? Thank you.