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    Subjectwrite data to a file from a kernel module

    I am trying to create a module for kernel 2.4.27 that writes data to a
    file when it
    receives a packet from the network interface card. In the code below
    the pkt_handler function is called each time a packet is received. A
    while after the insmod, the CPU reaches 100% and the pc freezes.

    Is there something wrong with the code or is there an alternate way to
    write data to a file? I think the problem is because the opening and
    writing are happening too often. Don't tell me to use the proc
    filesystem, it is
    not appropriate in my case.

    Thanks in advance.

    (I've commented out the semaphore operations because they don't seem to
    work as they are currently used)

    /* Packet handler. It is called by the kernel when a new packet has
    been received. */
    int pkt_handler (struct sk_buff *skb, struct net_device *dv, struct
    packet_type *pt)
    static int calls = 0;
    kfree_skb (skb);

    printk (KERN_ALERT "packet %d received\n", calls);
    if (calls++ > 10) {
    open_f_and_write ("/tmp/tmp.log");
    calls = 0;

    return 0;

    int open_f_and_write (const char *file_name)
    struct file *file = NULL;
    mm_segment_t fs;
    char *tmp;
    struct inode *inode;

    tmp = getname (file_name);

    file = filp_open (tmp, O_CREAT | O_WRONLY | O_APPEND, S_IRWXU);
    if (IS_ERR (file)) {
    int errno = PTR_ERR (file);
    printk (KERN_DEBUG "error %i\n", errno);
    return 2;
    if (!file->f_op->write) {
    fput (file);
    return 3;

    fs = get_fs ();
    set_fs (KERNEL_DS);
    //inode = file->f_dentry->d_inode;
    //down (&inode->i_sem);

    char *buffer = "write something\n";
    int p = file->f_op->write (file, buffer, m_strlen (buffer),
    printk (KERN_ALERT "write returned %d\n", p);
    set_fs (fs);
    putname (tmp);
    filp_close (file, NULL);

    return 0;
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      Last update: 2006-11-07 15:57    [W:0.020 / U:10.704 seconds]
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