Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

journal_set_features(9) [centos man page]

JOURNAL_SET_FEATURES(9) 				     The Linux Journalling API					   JOURNAL_SET_FEATURES(9)

NAME
journal_set_features - Mark a given journal feature in the superblock SYNOPSIS
int journal_set_features(journal_t * journal, unsigned long compat, unsigned long ro, unsigned long incompat); ARGUMENTS
journal Journal to act on. compat bitmask of compatible features ro bitmask of features that force read-only mount incompat bitmask of incompatible features DESCRIPTION
Mark a given journal feature as present on the superblock. Returns true if the requested features could be set. AUTHORS
Roger Gammans <rgammans@computer-surgery.co.uk> Author. Stephen Tweedie <sct@redhat.com> Author. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 JOURNAL_SET_FEATURES(9)

Check Out this Related Man Page

JOURNAL_TRY_TO_FREE_(9) 				     The Linux Journalling API					   JOURNAL_TRY_TO_FREE_(9)

NAME
journal_try_to_free_buffers - try to free page buffers. SYNOPSIS
int journal_try_to_free_buffers(journal_t * journal, struct page * page, gfp_t gfp_mask); ARGUMENTS
journal journal for operation page to try and free gfp_mask we use the mask to detect how hard should we try to release buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to release the buffers. DESCRIPTION
For all the buffers on this page, if they are fully written out ordered data, move them onto BUF_CLEAN so try_to_free_buffers can reap them. This function returns non-zero if we wish try_to_free_buffers to be called. We do this if the page is releasable by try_to_free_buffers. We also do it if the page has locked or dirty buffers and the caller wants us to perform sync or async writeout. This complicates JBD locking somewhat. We aren't protected by the BKL here. We wish to remove the buffer from its committing or running transaction's ->t_datalist via __journal_unfile_buffer. This may *change* the value of transaction_t->t_datalist, so anyone who looks at t_datalist needs to lock against this function. Even worse, someone may be doing a journal_dirty_data on this buffer. So we need to lock against that. journal_dirty_data will come out of the lock with the buffer dirty, which makes it ineligible for release here. Who else is affected by this? hmm... Really the only contender is do_get_write_access - it could be looking at the buffer while journal_try_to_free_buffer is changing its state. But that cannot happen because we never reallocate freed data as metadata while the data is part of a transaction. Yes? Return 0 on failure, 1 on success AUTHORS
Roger Gammans <rgammans@computer-surgery.co.uk> Author. Stephen Tweedie <sct@redhat.com> Author. COPYRIGHT
Kernel Hackers Manual 2.6. July 2010 JOURNAL_TRY_TO_FREE_(9)
Man Page

15 More Discussions You Might Find Interesting

1. Fedora

Is UNIX an open source OS ?

Hi everyone, I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX. Ok onto business, my questions are-: Was/Is UNIX ever an open source operating system ? If UNIX was... (21 Replies)
Discussion started by: sreyan32
21 Replies

2. UNIX for Beginners Questions & Answers

Weird 'find' results

Hello and thanks in advance for any help anyone can offer me I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
Discussion started by: bodisha
14 Replies

3. UNIX for Beginners Questions & Answers

Set hard block limit for user using quota

hi all, i have installed quota on my centos 7 machine and its what im after (setting size limit on users, so they cant fill the hard drive) i want to now make this part of my create user script for my sftp server so i want to do a echo and a read command so i capture the limit they enter... (0 Replies)
Discussion started by: robertkwild
0 Replies

4. UNIX for Beginners Questions & Answers

Best performance UNIX just for HOST Virtualization?

Hi everybody, Which Unix base OS have best performance for HOST virtualization? I tested SmartOS but it needs another OS to connect remotely! Thanks in advance. (11 Replies)
Discussion started by: mbzadegan
11 Replies

5. UNIX for Beginners Questions & Answers

How to increment version inside a file?

Hi All, I need to write a shell script which opens a file and increments the version(text) within the file every time the script runs. For example: $ cat docker_file.yml version: '3.1' services: ui: image: repo-srv.dev.io:5000/facebook/ui:0.0.2-QA1 $ So, I would like... (6 Replies)
Discussion started by: akshayupadhayay
6 Replies

6. Programming

DB2 convert digits to binary format

Dear Team We use DB2 v10.5 and using DBArtisan tool Can someone please guide how to convert digits to binary numbers using db2 feature. Ex> for number 9 , binary should be 1001 ( 8+1) Any help appreciated. Thanks (2 Replies)
Discussion started by: Perlbaby
2 Replies

7. UNIX for Advanced & Expert Users

Tar Command

hi folks, how to using tar with exclude directory and compress it using tar.Z i only know how to exclude dir only with this command below: tar -cvf /varios/restore/test.tar -X excludefile.txt /jfma/test1/ how to compress it using 1 command? Thanx Please use CODE tags as... (6 Replies)
Discussion started by: only
6 Replies

8. UNIX for Advanced & Expert Users

CentOS7 restoring file capabilities

Quite an obscure question I think. We have a rebuild process for remote sites that allows us to PXE rebuild a till (actually a PC with a touch screen and various fancy bits) running CentOS. The current CentOS5 tills work just fine with a tar image restore and some personalisation. Sadly,... (4 Replies)
Discussion started by: rbatte1
4 Replies

9. Docker

Docker learning Phase-I

Hello All, I had recently learnt a bit of Docker(which provides containerization process). Here are some of my learning points from it. Let us start first with very basic question: What is Docker: Docker is a platform for sysadmins and developers to DEPLOY, DEVELOP and RUN applications ... (7 Replies)
Discussion started by: RavinderSingh13
7 Replies

10. UNIX for Advanced & Expert Users

Shopt -s histappend

What is the point of this? Whenever I close my shell it appends to the history file without adding this. I have never seen it overwrite my history file. # When the shell exits, append to the history file instead of overwriting it shopt -s histappend (3 Replies)
Discussion started by: cokedude
3 Replies

11. UNIX for Beginners Questions & Answers

Unsure why access time on a directory change isn't changing

Hello... And thanks in advance for any help anyone can offer me I was trying to work out the differences between displaying modify, access, and change times with the 'ls' command. Everything seems in order when I look at files, but the access time on a directory doesn't seem to change when I... (4 Replies)
Discussion started by: bodisha
4 Replies

12. UNIX for Beginners Questions & Answers

CentOS 6 ran out of space, need to reclaim it

Hello everyone, I am having an issue here with CentOS release 6.6 (Final) that shows all of the space used up, but I can't tell where the space went. Seemingly I am using up 100%, according to df -h Filesystem Size Used Avail Use% Mounted on... (27 Replies)
Discussion started by: DannyBoyCentOS
27 Replies

13. Shell Programming and Scripting

Controlling user input

I'm trying to use a bash script for a psych experiment that involves listening to sound files and responding. If I have something like the code below, how can I make sure that a key press is assigned to RESPONSE only after the second echo statement? for i in 1 2 3; do echo "Ready?" sleep 2 ... (10 Replies)
Discussion started by: darwin_886
10 Replies

14. Shell Programming and Scripting

[TIP] Processing YAML files with yq

After the success of the jq - tool for parsing and manipulating JSON-Data someone wrote a tool called yq, which aims to be the same for YAML, what jq is for JSON. Seems to work fine. I'll definitely give it a chance in future. Example YAML-File: --- !ruby/object:Puppet::Node::Facts ... (1 Reply)
Discussion started by: stomp
1 Replies

15. What is on Your Mind?

Please Welcome Dave Munro to the Moderator Team!

Dear All, I am very pleased to announce that Dave Munro (gull04) is joining the Moderation Team, after being a very valuable member of UNIX.com for 15+ years. Dave is an IT Consultant with 30 years of experience this year, has worked in many of the industry vertical market segments and has... (6 Replies)
Discussion started by: Neo
6 Replies