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swim3: fix interruptible_sleep_on race 

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>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Arnd Bergmann 2014-02-26 12:01:44 +01:00 committed by Jens Axboe
parent 7b8a3d22ba
commit 106fd892bc
1 changed files with 11 additions and 7 deletions
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18
drivers/block/swim3.c
View File

@ -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;
}