Messages in this thread Patch in this message | | | Date | Wed, 4 Jun 2003 01:58:02 +0100 (BST) | From | "P. Benie" <> | Subject | [PATCH] [2.5] Non-blocking write can block |
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Non-blocking writes to a tty will block if there is a blocking write waiting for the atomic_write semaphore.
Peter
--- linux-2.5.70/drivers/char/tty_io.c.orig 2003-06-03 21:34:42.000000000 +0100 +++ linux-2.5.70/drivers/char/tty_io.c 2003-06-04 01:40:33.000000000 +0100 @@ -687,8 +687,13 @@ { ssize_t ret = 0, written = 0;
- if (down_interruptible(&tty->atomic_write)) { - return -ERESTARTSYS; + if (file->f_flags & O_NONBLOCK) { + if (down_trylock(&tty->atomic_write)) + return -EAGAIN; + } + else { + if (down_interruptible(&tty->atomic_write)) + return -ERESTARTSYS; } if ( test_bit(TTY_NO_WRITE_SPLIT, &tty->flags) ) { lock_kernel(); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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