ext4 uses generic_file_llseek for lseek, and I find this implementation for that in fs/read_write.c:
So really, nothing to it, and the only thing that could be blocking is that mutex...
I think you've saturated the kernel with so many simultaneous system calls to the same inode that they're competing for i_mutex.
I don't think this'd happen if you hadn't opened it with O_DIRECT. Caching is your friend...
Last edited by Corona688; 09-13-2011 at 11:05 AM..
Hi,
I am accepting a string from user. compare this output with the awk output as below...
echo "\n\n\tDay : \c"
read day
awk '{ if($day == $2) { if ($mon == $1) { print "Yes" }}}' syslog.txt
I am getting the follwoing error
awk: Field $() is not correct.
The input line... (5 Replies)
recently my project needs me to lseek a position over 4G size....
i found in linux or unix the parameters are all ulong 32 bits...the limit dooms the movement of a position over 4G
I was told that i should lseek64 to meet my need... but i have no idea where i can get the function neither by "man... (8 Replies)
Hey Guys
I am trying to implement the malloc function for my OS class and I am having a little trouble with it. I would be really grateful if I could get some hints on this problem.
So I am using a doubly-linked list as my data structure and I have to allocate memory for it (duh...). The... (1 Reply)
Hey Guys
Some of my friends have got together and we are trying to write a basic kernel similar to Linux. I am trying to implement the malloc function in C and I am using a doubly linked list as the primary data structure. I need to allocate memory for this link list (duh...) and I don't feel... (2 Replies)
I know there is lseek() function that will allow to write or read from certain position in the file. Is there similar function that will let do same but for array rather then file? (9 Replies)
I tried to use lseek system call to determine the number of bytes in a file. To do so, I used open system call with O_APPEND flag to open a file. As lseek returns the current offset so I called lseek for opened file with offset as zero and whence as SEEK_CUR. So I guess it must return the number of... (3 Replies)
I think both write at the end of the file ......
but is there a sharp difference between those 2 instruction .....
thank you
this is my 3rd question today forgive me :D (1 Reply)
Hi,
We are facing issues while backing up our 1205 GB filesystem on LTO5 Tape. During backup the "backup: The lseek call failed." messages were generated, I want to know why these messages were generating
AIX version is: 6100-08-00-0000
backup: The date of this level 0 backup is Mon Mar 11... (4 Replies)
The following code:
int fd;
if (fd = open("mem", O_RDONLY) == -1)
return 1;
if (lseek(fd, 0, SEEK_SET) == -1) {
char *buf = malloc(512);
buf = strerror(errno);
printf("%s\n", buf);
return 1;
}
always returns with "illegal seek"... (2 Replies)
Discussion started by: Sir_Tomasz
2 Replies
LEARN ABOUT FREEBSD
mac_free
MAC_FREE(3) BSD Library Functions Manual MAC_FREE(3)NAME
mac_free -- free MAC label
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/mac.h>
int
mac_free(mac_t label);
DESCRIPTION
The mac_free() function frees the storage allocated to contain a mac_t.
RETURN VALUES
The mac_free() function always returns 0. WARNING: see the notes in the BUGS section regarding the use of this function.
SEE ALSO mac(3), mac_get(3), mac_prepare(3), mac_set(3), mac_text(3), posix1e(3), mac(4), mac(9)STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17. Discussion of the draft continues on the cross-platform POSIX.1e implementation mailing
list. To join this list, see the FreeBSD POSIX.1e implementation page for more information.
HISTORY
Support for Mandatory Access Control was introduced in FreeBSD 5.0 as part of the TrustedBSD Project.
BUGS
POSIX.1e specifies that mac_free() will be used to free text strings created using mac_to_text(3). Because mac_t is a complex structure in
the TrustedBSD implementation, mac_free() is specific to mac_3, and must not be used to free the character strings returned from
mac_to_text(). Doing so may result in undefined behavior.
BSD December 21, 2001 BSD