/g/ - syscall of the day: f(data)sync - Technology

Anonymous

syscall of the day: f(data)syn(...) 03/04/26(Wed)09:26:30 No.108292753

File: 1687829191911161.png (9 KB, 658x673)

syscall of the day: f(data)sync Anonymous 03/04/26(Wed)09:26:30 No.108292753 Archived

previous: >>108285124
#define __NR_fsync                74
#define __NR_fdatasync            75
https://man7.org/linux/man-pages/man2/fsync.2.html

tl;dr:
flush file data to disk

the tl;dr honestly covers pretty much all of it for this one, lol. i guess it's maybe interesting that it blocks? plus the option for metadata-less flushes
i guess the one other thing worth mentioning is the EIO error case, where you can get some write-like errors when trying to flush
i'm sure these are useful to someone trying to do optimizations, but they're not something i've ever taken advantage of

relevant resources:
man man
man syscalls
https://man7.org/linux/man-pages/
https://linux.die.net/man/
https://elixir.bootlin.com/linux/
https://elixir.bootlin.com/musl/
https://elixir.bootlin.com/glibc/

Anonymous
03/04/26(Wed)10:00:51 No.108292995

Anonymous 03/04/26(Wed)10:00:51 No.108292995

File: chiyo;yotsuba:caption:int(...).jpg (96 KB, 1185x1215)

96 KB JPG

>>108292753
guess it can be useful for synchronization in some rare cases for network filesystems like NFS?
NFS by default uses async writes, data is flushed on close() of fsync(). Say you open a file and never close it. You continuously write to it on NFS client and expect to read it immediately on the server or another client, you could use fsync() for that.
Some shitty FUSE filesystems don't implement flush on fsync() (or even close() for that matter, muh "caching"), which leads to all sorts of synchronization issues (write and close a file, yet the changes aren't commited to the storage yet).

Anonymous
03/04/26(Wed)10:56:25 No.108293359

Anonymous 03/04/26(Wed)10:56:25 No.108293359

bampu

Anonymous
03/04/26(Wed)11:01:23 No.108293395

Anonymous 03/04/26(Wed)11:01:23 No.108293395

>>108292753
>pic
That's from the "OL has to wake up and go to work" set, right? Saucenao is garbage these days.

Anonymous
03/04/26(Wed)12:22:23 No.108294022

Anonymous 03/04/26(Wed)12:22:23 No.108294022

Remember to do a sync everytime you do a dd, kids!

Anonymous
03/04/26(Wed)13:52:00 No.108294662

Anonymous 03/04/26(Wed)13:52:00 No.108294662

Penis water tap lmao

Anonymous
03/04/26(Wed)16:08:47 No.108295663

Anonymous 03/04/26(Wed)16:08:47 No.108295663

>>108292753
Bump.

Anonymous
03/04/26(Wed)17:14:45 No.108296183

Anonymous 03/04/26(Wed)17:14:45 No.108296183

>>108294022
>dd
what's a dd?

Anonymous
03/04/26(Wed)17:25:13 No.108296266

Anonymous 03/04/26(Wed)17:25:13 No.108296266

>>108296183
Dick Destroyer.

Anonymous
03/04/26(Wed)20:22:43 No.108297413

Anonymous 03/04/26(Wed)20:22:43 No.108297413

>>108296183
It's the most based way to copy information. It is more commonly used to completely wipe hard drives, because if you type a command even slightly wrong, that's what you do.

Anonymous
03/04/26(Wed)20:34:38 No.108297465

Anonymous 03/04/26(Wed)20:34:38 No.108297465

>>108292753
oh no why is shy crying

Anonymous
03/04/26(Wed)21:44:44 No.108297887

Anonymous 03/04/26(Wed)21:44:44 No.108297887

>>108297413
i use it for formatting iso files onto USB drives
>>108293395
no idea sorry
>>108297465
because people don't post in her syscall threads :<

Anonymous
03/05/26(Thu)00:26:52 No.108298842

Anonymous 03/05/26(Thu)00:26:52 No.108298842

bampu

Anonymous
03/05/26(Thu)02:22:05 No.108299305

Anonymous 03/05/26(Thu)02:22:05 No.108299305

>>108297887
Just cp distro.iso /dev/sdb
dd is placebo

Anonymous
03/05/26(Thu)03:24:25 No.108299639

Anonymous 03/05/26(Thu)03:24:25 No.108299639

>>108296183
demand draft
https://en.wikipedia.org/wiki/Demand_draft