LOCKS_MANDATORY_AREA(9) The Linux VFS LOCKS_MANDATORY_AREA(9)NAME
locks_mandatory_area - Check for a conflicting lock
int locks_mandatory_area(int read_write, struct inode * inode, struct file * filp, loff_t offset, size_t count);
FLOCK_VERIFY_WRITE for exclusive access, FLOCK_VERIFY_READ for shared
the file to check
how the file was opened (if it was)
start of area to check
length of area to check
Searches the inode's list of locks to find any POSIX locks which conflict. This function is called from rw_verify_area and
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 LOCKS_MANDATORY_AREA(9)
Check Out this Related Man Page
VFS_LOCK_FILE(9) The Linux VFS VFS_LOCK_FILE(9)NAME
vfs_lock_file - file byte range lock
int vfs_lock_file(struct file * filp, unsigned int cmd, struct file_lock * fl, struct file_lock * conf);
The file to apply the lock to
type of locking operation (F_SETLK, F_GETLK, etc.)
The lock to be applied
Place to return a copy of the conflicting lock, if found.
A caller that doesn't care about the conflicting lock may pass NULL as the final argument.
If the filesystem defines a private ->lock method, then conf will be left unchanged; so a caller that cares should initialize it to some
To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX locks, the ->lock interface may return asynchronously, before
the lock has been granted or denied by the underlying filesystem, if (and only if) lm_grant is set. Callers expecting ->lock to return
asynchronously will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) the request is for a blocking lock. When ->lock
does return asynchronously, it must return FILE_LOCK_DEFERRED, and call ->lm_grant when the lock request completes. If the request is for
non-blocking lock the file system should return FILE_LOCK_DEFERRED then try to get the lock and call the callback routine with the result.
If the request timed out the callback routine will return a nonzero return code and the file system should release the lock. The file
system is also responsible to keep a corresponding posix lock when it grants a lock so the VFS can find out which locks are locally held
and do the correct lock cleanup when required. The underlying filesystem must not drop the kernel lock or call ->lm_grant before returning
to the caller with a FILE_LOCK_DEFERRED return code.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 VFS_LOCK_FILE(9)
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)
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)
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)
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
So, I would like... (6 Replies)
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)
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?
Please use CODE tags as... (6 Replies)
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)
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)
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)
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)
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
Filesystem Size Used Avail Use% Mounted on... (27 Replies)
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
... (10 Replies)
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.
... (1 Reply)
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)