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Subject[PATCH 04/16] swim3: fix interruptible_sleep_on race
Date
interruptible_sleep_on is racy and going away. This replaces the one
caller in the swim3 driver with the equivalent race-free
wait_event_interruptible call. Since we're here already, this
also fixes the case where we get interrupted from atomic context,
which used to just spin in the loop.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <axboe@kernel.dk>
---
drivers/block/swim3.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 20e061c..c74f7b5 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -30,6 +30,7 @@
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/spinlock.h>
+#include <linux/wait.h>
#include <asm/io.h>
#include <asm/dbdma.h>
#include <asm/prom.h>
@@ -840,14 +841,17 @@ static int grab_drive(struct floppy_state *fs, enum swim_state state,
spin_lock_irqsave(&swim3_lock, flags);
if (fs->state != idle && fs->state != available) {
++fs->wanted;
- while (fs->state != available) {
+ /* this will enable irqs in order to sleep */
+ if (!interruptible)
+ wait_event_lock_irq(fs->wait,
+ fs->state == available,
+ swim3_lock);
+ else if (wait_event_interruptible_lock_irq(fs->wait,
+ fs->state == available,
+ swim3_lock)) {
+ --fs->wanted;
spin_unlock_irqrestore(&swim3_lock, flags);
- if (interruptible && signal_pending(current)) {
- --fs->wanted;
- return -EINTR;
- }
- interruptible_sleep_on(&fs->wait);
- spin_lock_irqsave(&swim3_lock, flags);
+ return -EINTR;
}
--fs->wanted;
}
--
1.8.3.2


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