02-19-2010
vnode file access
Hey, I'm new to the bsd kernel and i'm implementing a vop_read function. The problem I'm having is determining
1. Which physical block is being read given the vnode's logical block #
2. How many bytes are being read
Any tips are greatly appreciated!
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi
I need to access files from a specific folder of a Linux system from an another Linux System Remotely.
I know how to, Export a folder on One SCO System & can access the same by using Import via., NFS in the Sco Unix SVR4 System using the scoadmin utility.
Also, I know to use mount -t ... (2 Replies)
Discussion started by: S.Vishwanath
2 Replies
2. Programming
INFO:
The program should enter a circle radius and Id for that circle to a file, then it should search for that id and print the radius for that circle.
PROBLEM:
This program compiles but it's not searching properly.
Circle.h
#ifndef CIRCLE_H
#define CIRCLE_H
#include <iostream>... (0 Replies)
Discussion started by: VersEtreOuNe
0 Replies
3. Cybersecurity
Hello,
i need some help/advice on how to solve a particular problem.
these are the users:
|name | group |
---------- ---------------
|boss | department1 |
|assistant | department1 |
|employee | department1 |
|spy | department2 |
this is the... (0 Replies)
Discussion started by: elzalem
0 Replies
4. Programming
I'm in the UNIX environment. I'd like to read a Microsoft Access MDB file, and write the contents of that file into an ASCII text file. I want to write a C program to do this.
Does anyone know if there's already source code out there that does this?
Please advise. Thanks. (3 Replies)
Discussion started by: serendipity1276
3 Replies
5. UNIX for Dummies Questions & Answers
hi all,
i want to know y kernel is giving access for multiple users to access a file when one user may be the owner is executing that file. Because other user can manipulate that file when the other user is executing that file, it will give the unexpected result to owner . plz help me... (1 Reply)
Discussion started by: jimmyuk
1 Replies
6. IP Networking
Hi
Good Day, i would like to ask for further info about my problems experiencing this evening. Im a PPP0 connection in the internet using 3G located in asia pacific region.i had this problem this evening in my INTERNET connections that there are some sites i can't open example ( Gizmodo.com,... (2 Replies)
Discussion started by: jao_madn
2 Replies
7. Solaris
Hi All,
I want to configure samba share permission so that only directory creator/owner has a read and write permission and other users should not have any read/write access to that folder.Will that be possible and how can this be achieved within samba configuration.
Regards,
Sahil (1 Reply)
Discussion started by: sahil_shine
1 Replies
8. Proxy Server
Dear all experts here,
:)
I would like to install a proxy server on Linux server to perform solely to control the access of Web server.
In this case, some of my vendor asked me to try Squid and I have installed it onto my Linux server.
I would like know how can I set the configuration to... (1 Reply)
Discussion started by: kwliew999
1 Replies
9. Solaris
I'm trying to list all open sockets and their PIDs on Solaris 10 in C++.
In Solaris 11, they made this really simple by adding the PID to the mib structs (example, tcpConnCreationProcess in inet/mib2.h). This functionality isn't in Solaris 10, and can be seen in the new netstat source code.
... (1 Reply)
Discussion started by: mrmoss
1 Replies
10. Shell Programming and Scripting
We have three files as mentioned below:
1. main_file.txt: This is the file in which all operations will be done. Which means this file will be signed by using the below two files
2. signature_file.txt: This is a status file and contains two signatures.
3. command.txt:file contains two commands... (2 Replies)
Discussion started by: chetanojha
2 Replies
LEARN ABOUT DEBIAN
vop_getextattr
VOP_GETEXTATTR(9) BSD Kernel Developer's Manual VOP_GETEXTATTR(9)
NAME
VOP_GETEXTATTR -- retrieve named extended attribute from a vnode
SYNOPSIS
#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/extattr.h>
int
VOP_GETEXTATTR(struct vnode *vp, int attrnamespace, const char *name, struct uio *uio, size_t *size, struct ucred *cred, struct thread *td);
DESCRIPTION
This vnode call may be used to retrieve a specific named extended attribute from a file or directory.
Its arguments are:
vp The vnode of the file or directory.
attrnamespace Integer constant indicating which extended attribute namespace the attribute name is present in.
name Pointer to a null-terminated character string containing the attribute name.
uio The location of the data to be read.
size If not NULL, on return it will contain the number of bytes required to read all of the attribute data. In most cases uio will
be NULL when size is not, and vise versa.
cred The user credentials to use in authorizing the request.
td The thread requesting the extended attribute.
The cred pointer may be NULL to indicate that access control checks are not to be performed, if possible. This cred setting might be used to
allow the kernel to authorize extended attribute retrieval that the active process might not be permitted to do.
Extended attribute semantics may vary by file system implementing the call. More information on extended attributes may be found in
extattr(9).
LOCKS
The vnode will be locked on entry and should remain locked on return.
RETURN VALUES
On success, zero will be returned, and the uio structure will be updated to reflect data read. Otherwise, an appropriate error code is
returned.
ERRORS
[ENOATTR] The requested attribute was not defined for this vnode.
[EACCES] The the caller does not have the appropriate privilege.
[ENXIO] The request was not valid in this file system for the specified vnode and attribute name.
[ENOMEM] Sufficient memory is not available to fulfill the request.
[EFAULT] The uio structure refers to an invalid userspace address.
[EINVAL] The name, namespace, or uio argument is invalid.
[EOPNOTSUPP] The file system does not support VOP_GETEXTATTR().
SEE ALSO
extattr(9), vnode(9), VOP_LISTEXTATTR(9), VOP_SETEXTATTR(9)
BUGS
By passing in the empty string as the attribute name, some file systems will return a list of defined names on the target vnode for the
requested namespace. This is a bad API, and will be replaced by an explicit VOP.
BSD
December 23, 1999 BSD