Stack Overflow
Stack Overflow

Questions tagged [ext4]

Ext 4 is a linux filesystem.

Ext4 is a filesystem mostly used under linux. Other versions are ext, ext2 and ext3.

See Wikipedia for details on ext and ext4.

316 questions
2
votes
0 answers

Copying files to an unmounted ext4 image file

With FAT32 images, copying files to an unmounted image is possible with the mcopy command: mcopy -v -i [image file] -s [files to copy] ::/ However, this is not possible with an ext4-based image file. Is there an equivalent command to achieve the…
Ozmydis
  • 53
  • 4
2
votes
0 answers

What is the difference between O_DIRECT and DAX with ext4 filesystem on X86-64?

I understand the O_DIRECT flag when opening a file via the system call. The file with this flag is read without buffering. There are restrictions of read offset and the number of bytes of each read opearation. However, DAX is a parameter of the…
Jigao Luo
  • 127
  • 1
  • 6
2
votes
0 answers

Is trimming beginning of a file using fallocate with FALLOC_FL_COLLAPSE_RANGE atomic on ext4?

I'd like to know what are possible states if system crashes while trimming beginning of a file using fallocate with FALLOC_FL_COLLAPSE_RANGE flag. Is it possible that only part of the blocks we want to trim is absent, and some blocks are still…
greghvk
  • 76
  • 4
2
votes
0 answers

canned_fs_config vs fs_config in Android ext4 utils

When creating the filesystem images Android uses the utility mkuserimg_mke2fs. The utility can be provided a config file with the uid/gid and the permissions. The utility uses the fs_config function when a mountpoint is passed to it and uses the…
Venkata
  • 121
  • 2
2
votes
1 answer

debugfs set_inode_field ctime with nanoseconds

I'm using debugfs to change the ctime of a file (programm rotine attached to ctime of this specific file) on an ext4 file system. The therefor used command is: debugfs -w -R 'set_inode_field foo/bar ctime 20130503145204' /dev/vdb1 but this is…
cnbhl
  • 41
  • 4
2
votes
1 answer

Can the data=journal mode of EXT4 avoid user data loss?

journal mode data=journal mode provides full data and metadata journaling. All new data is written to the journal first, and then to its final location. In the event of a crash, the journal can be replayed, bringing both data and metadata into a…
benqwu
  • 21
  • 3
2
votes
0 answers

How to extract F2FS file system based disk img files?

I am writing a program in windows (C#) to extract disk images from AOSP. I am using simg2img, but to no avail. Simg2img only supports EXT4 based file systems and some of my IMG files are written in F2FS. How do I extract these files? I have been…
Manasvini Ganesh
  • 483
  • 5
  • 16
2
votes
1 answer

Yocto Custom Layer run Tune2fs on do_rootfs after mkfs.ext4

I'm using Yocto on Ubuntu 18.04 with the Warrior Branch of Meta-Tegra in order to try to integrate the RAUC Open Source project for Linux Firmware Updates. I've learned that U-Boot has issues writing to EXT4 partitions ( to update the U-Boot Env )…
PhilBot
  • 748
  • 18
  • 85
  • 173
2
votes
0 answers

How can I determine the maximum possible size a single file can have on an empty ext4 drive?

I have an empty ext4 formated hard disk and would like to create a single file that takes up all available disk space. And I would like to know the size of this file before creating it. My approach was to run 'df -k' to get the available space and…
user11248138
  • 31
  • 3
2
votes
1 answer

Project Quotas in ext4

This is regarding setting of Project Quotas/ Directory Quotas on ext4 filesystems. The patch for allowing Project Quotas in ext4 filesystems was submitted via patch https://lore.kernel.org/patchwork/patch/541895/ . I have tried the below steps…
Manish Gajjaria
  • 21
  • 1
  • 2
2
votes
1 answer

Ext2/3: Block Type Clarification: IND vs DIND vs TIND

I'm seeing references to "IND" vs "DIND" vs "TIND" block-types in a few places, whereas the definition in the code is very terse: (https://github.com/torvalds/linux/blob/master/fs/ext4/ext4.h#L362) #define EXT4_NDIR_BLOCKS 12 #define…
Dustin Oprea
  • 9,673
  • 13
  • 65
  • 105
2
votes
1 answer

Can Flink output be sinked to a NFS or GPFS file system?

Flink has a RollingFileSink which per the documentation works with HDFS (Hadoop). Are there similar classes which can be used to sink data to file systems such as NFS, ext4 or…
victtim
  • 790
  • 5
  • 17
2
votes
0 answers

Format SD card to EXT4 in Windows command line

For part of some application it is required to write a VBScript to format SD card to EXT4 fs. Application is running on Windows OS. I found that the format command in CMD can perform disk formatting but only to FAT*, NTFSm UDF and ReFS. Is there any…
lquasar
  • 45
  • 1
  • 6
2
votes
1 answer

Get filesystem creation date in C

I need to know the creation datetime of the filesystem on a disk (in a Linux machine) with C. I would like to avoid using shell commands, such as tune2fs -l /dev/sdb2 | grep 'Filesystem created:' and make a parser. Thanks
Rockietto
  • 109
  • 1
  • 11
2
votes
1 answer

How to know which address space a buffer head is mapped to?

In the jbd2 source code, any modification in the File System is mapped into a handle_t structure (per process) that later is used to map the buffer_head to the transaction_t which this handle is going to be part of. As far as I could understand,…
campescassiano
  • 809
  • 5
  • 18
1 2 3
…
21 22