[PATCH] drivers/block/floppy.c: dont free_irq() from irq context
free_irq() should not be executed from softirq context.
Found by the lock validator. The fix is to push fd_free_irq() into
keventd. The code validates fine with this patch applied.
(akpm: this is revolting, but so is floppy.c)
[akpm@osdl.org: added flush_scheduled_work()]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 840919b..d3ad908 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -250,6 +250,18 @@
#include <linux/cdrom.h> /* for the compatibility eject ioctl */
#include <linux/completion.h>
+/*
+ * Interrupt freeing also means /proc VFS work - dont do it
+ * from interrupt context. We push this work into keventd:
+ */
+static void fd_free_irq_fn(void *data)
+{
+ fd_free_irq();
+}
+
+static DECLARE_WORK(fd_free_irq_work, fd_free_irq_fn, NULL);
+
+
static struct request *current_req;
static struct request_queue *floppy_queue;
static void do_fd_request(request_queue_t * q);
@@ -4433,6 +4445,13 @@
return 0;
}
spin_unlock_irqrestore(&floppy_usage_lock, flags);
+
+ /*
+ * We might have scheduled a free_irq(), wait it to
+ * drain first:
+ */
+ flush_scheduled_work();
+
if (fd_request_irq()) {
DPRINT("Unable to grab IRQ%d for the floppy driver\n",
FLOPPY_IRQ);
@@ -4522,7 +4541,7 @@
if (irqdma_allocated) {
fd_disable_dma();
fd_free_dma();
- fd_free_irq();
+ schedule_work(&fd_free_irq_work);
irqdma_allocated = 0;
}
set_dor(0, ~0, 8);
@@ -4633,6 +4652,8 @@
/* eject disk, if any */
fd_eject(0);
+ flush_scheduled_work(); /* fd_free_irq() might be pending */
+
wait_for_completion(&device_release);
}