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Date: Thu, 20 Feb 2014 15:44:25 -0500
From: Tejun Heo <tj@...nel.org>
To: laijs@...fujitsu.com
Cc: linux-kernel@...r.kernel.org, Tejun Heo <tj@...nel.org>,
Jiri Kosina <jkosina@...e.cz>
Subject: [PATCH 3/9] floppy: don't use PREPARE_[DELAYED_]WORK
PREPARE_[DELAYED_]WORK() are being phased out. They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.
floppy has been multiplexing floppy_work and fd_timer with multiple
work functions. Introduce floppy_work_workfn() and fd_timer_workfn()
which invoke floppy_work_fn and fd_timer_fn respectively and always
use the two functions as the work functions and update the users to
set floppy_work_fn and fd_timer_fn instead of overriding work
functions using PREPARE_[DELAYED_]WORK().
It would probably be best to route this with other related updates
through the workqueue tree.
Lightly tested using qemu.
Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Jiri Kosina <jkosina@...e.cz>
---
drivers/block/floppy.c | 42 ++++++++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 14 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 2023043..8f5565b 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -961,17 +961,31 @@ static void empty(void)
{
}
-static DECLARE_WORK(floppy_work, NULL);
+static void (*floppy_work_fn)(void);
+
+static void floppy_work_workfn(struct work_struct *work)
+{
+ floppy_work_fn();
+}
+
+static DECLARE_WORK(floppy_work, floppy_work_workfn);
static void schedule_bh(void (*handler)(void))
{
WARN_ON(work_pending(&floppy_work));
- PREPARE_WORK(&floppy_work, (work_func_t)handler);
+ floppy_work_fn = handler;
queue_work(floppy_wq, &floppy_work);
}
-static DECLARE_DELAYED_WORK(fd_timer, NULL);
+static void (*fd_timer_fn)(void) = NULL;
+
+static void fd_timer_workfn(struct work_struct *work)
+{
+ fd_timer_fn();
+}
+
+static DECLARE_DELAYED_WORK(fd_timer, fd_timer_workfn);
static void cancel_activity(void)
{
@@ -982,7 +996,7 @@ static void cancel_activity(void)
/* this function makes sure that the disk stays in the drive during the
* transfer */
-static void fd_watchdog(struct work_struct *arg)
+static void fd_watchdog(void)
{
debug_dcl(DP->flags, "calling disk change from watchdog\n");
@@ -993,7 +1007,7 @@ static void fd_watchdog(struct work_struct *arg)
reset_fdc();
} else {
cancel_delayed_work(&fd_timer);
- PREPARE_DELAYED_WORK(&fd_timer, fd_watchdog);
+ fd_timer_fn = fd_watchdog;
queue_delayed_work(floppy_wq, &fd_timer, HZ / 10);
}
}
@@ -1005,7 +1019,8 @@ static void main_command_interrupt(void)
}
/* waits for a delay (spinup or select) to pass */
-static int fd_wait_for_completion(unsigned long expires, work_func_t function)
+static int fd_wait_for_completion(unsigned long expires,
+ void (*function)(void))
{
if (FDCS->reset) {
reset_fdc(); /* do the reset during sleep to win time
@@ -1016,7 +1031,7 @@ static int fd_wait_for_completion(unsigned long expires, work_func_t function)
if (time_before(jiffies, expires)) {
cancel_delayed_work(&fd_timer);
- PREPARE_DELAYED_WORK(&fd_timer, function);
+ fd_timer_fn = function;
queue_delayed_work(floppy_wq, &fd_timer, expires - jiffies);
return 1;
}
@@ -1334,8 +1349,7 @@ static int fdc_dtr(void)
* Pause 5 msec to avoid trouble. (Needs to be 2 jiffies)
*/
FDCS->dtr = raw_cmd->rate & 3;
- return fd_wait_for_completion(jiffies + 2UL * HZ / 100,
- (work_func_t)floppy_ready);
+ return fd_wait_for_completion(jiffies + 2UL * HZ / 100, floppy_ready);
} /* fdc_dtr */
static void tell_sector(void)
@@ -1440,7 +1454,7 @@ static void setup_rw_floppy(void)
int flags;
int dflags;
unsigned long ready_date;
- work_func_t function;
+ void (*function)(void);
flags = raw_cmd->flags;
if (flags & (FD_RAW_READ | FD_RAW_WRITE))
@@ -1454,9 +1468,9 @@ static void setup_rw_floppy(void)
*/
if (time_after(ready_date, jiffies + DP->select_delay)) {
ready_date -= DP->select_delay;
- function = (work_func_t)floppy_start;
+ function = floppy_start;
} else
- function = (work_func_t)setup_rw_floppy;
+ function = setup_rw_floppy;
/* wait until the floppy is spinning fast enough */
if (fd_wait_for_completion(ready_date, function))
@@ -1486,7 +1500,7 @@ static void setup_rw_floppy(void)
inr = result();
cont->interrupt();
} else if (flags & FD_RAW_NEED_DISK)
- fd_watchdog(NULL);
+ fd_watchdog();
}
static int blind_seek;
@@ -1863,7 +1877,7 @@ static int start_motor(void (*function)(void))
/* wait_for_completion also schedules reset if needed. */
return fd_wait_for_completion(DRS->select_date + DP->select_delay,
- (work_func_t)function);
+ function);
}
static void floppy_ready(void)
--
1.8.5.3
--
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