Make flush_to_ldisc properly handle parallel calls
This commit is contained in:
parent
80f506918f
commit
45242006e1
1 changed files with 13 additions and 16 deletions
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@ -402,28 +402,26 @@ static void flush_to_ldisc(struct work_struct *work)
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container_of(work, struct tty_struct, buf.work.work);
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container_of(work, struct tty_struct, buf.work.work);
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unsigned long flags;
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unsigned long flags;
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struct tty_ldisc *disc;
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struct tty_ldisc *disc;
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struct tty_buffer *tbuf, *head;
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char *char_buf;
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unsigned char *flag_buf;
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disc = tty_ldisc_ref(tty);
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disc = tty_ldisc_ref(tty);
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if (disc == NULL) /* !TTY_LDISC */
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if (disc == NULL) /* !TTY_LDISC */
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return;
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return;
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spin_lock_irqsave(&tty->buf.lock, flags);
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spin_lock_irqsave(&tty->buf.lock, flags);
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/* So we know a flush is running */
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set_bit(TTY_FLUSHING, &tty->flags);
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if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
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head = tty->buf.head;
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struct tty_buffer *head;
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if (head != NULL) {
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while ((head = tty->buf.head) != NULL) {
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tty->buf.head = NULL;
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int count;
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for (;;) {
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char *char_buf;
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int count = head->commit - head->read;
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unsigned char *flag_buf;
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count = head->commit - head->read;
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if (!count) {
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if (!count) {
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if (head->next == NULL)
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if (head->next == NULL)
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break;
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break;
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tbuf = head;
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tty->buf.head = head->next;
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head = head->next;
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tty_buffer_free(tty, head);
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tty_buffer_free(tty, tbuf);
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continue;
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continue;
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}
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}
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/* Ldisc or user is trying to flush the buffers
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/* Ldisc or user is trying to flush the buffers
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@ -445,9 +443,9 @@ static void flush_to_ldisc(struct work_struct *work)
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flag_buf, count);
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flag_buf, count);
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spin_lock_irqsave(&tty->buf.lock, flags);
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spin_lock_irqsave(&tty->buf.lock, flags);
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}
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}
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/* Restore the queue head */
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clear_bit(TTY_FLUSHING, &tty->flags);
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tty->buf.head = head;
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}
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}
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/* We may have a deferred request to flush the input buffer,
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/* We may have a deferred request to flush the input buffer,
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if so pull the chain under the lock and empty the queue */
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if so pull the chain under the lock and empty the queue */
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if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
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if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
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@ -455,7 +453,6 @@ static void flush_to_ldisc(struct work_struct *work)
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clear_bit(TTY_FLUSHPENDING, &tty->flags);
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clear_bit(TTY_FLUSHPENDING, &tty->flags);
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wake_up(&tty->read_wait);
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wake_up(&tty->read_wait);
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}
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}
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clear_bit(TTY_FLUSHING, &tty->flags);
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spin_unlock_irqrestore(&tty->buf.lock, flags);
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spin_unlock_irqrestore(&tty->buf.lock, flags);
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tty_ldisc_deref(disc);
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tty_ldisc_deref(disc);
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