Hello everyone, I want to create and read/write a file in Linux kernel or device driver, I have write some code, the file could be created successfully, but it can not be wrote in anything, the function "write" always return a negative number, the content of the file is still empty. The following code is what I wrote in my device driver, the code reference the function sys_open() in open.c and sys_write() in read_write.c, please give me a help, thanks!
struct file *filp;
char testbuf[100] = {0};
char *ptestbuf = NULL;
ssize_t count = 0;
ssize_t ret = 0;
int ii = 0;
filp = filp_open("/logfile", O_CREAT | O_WRONLY | O_TRUNC, 0666);
if (IS_ERR(filp))
printk("<0>Create record file error!\n\r");
for(ii = 0; ii < 100; ii++)
testbuf[ii] = 1;
ptestbuf = testbuf;
if (filp->f_mode & FMODE_WRITE)
{
struct inode *inode = filp->f_dentry->d_inode;
ret = locks_verify_area(FLOCK_VERIFY_WRITE, inode, filp, filp->f_pos, count);
if (!ret)
{
ssize_t (*write)(struct file *, const char *, size_t, loff_t *);
if (filp->f_op && (filp->f_op->write) != NULL)
{
write = filp->f_op->write;
count = 99;
ret = write(filp, (const char *)ptestbuf, count, &filp->f_pos);
printk("<0>After write, ret = %d \n\r");
}
}
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
