Move wait queue declaration and unplug to dm_wait_for_completion.
The purpose is to minimize duplicate code in the further patches.
The patch reorders functions a little bit. It doesn't change any
functionality. For proper non-deadlock operation, it is required
hat add_wait_queue happens before set_current_state(interruptible)
and before the test for !atomic_read(&md->pending) --- and this
patch follows that.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
Index: linux-2.6.29-rc3-devel/drivers/md/dm.c
===================================================================
--- linux-2.6.29-rc3-devel.orig/drivers/md/dm.c 2009-02-05 05:52:18.000000000 +0100
+++ linux-2.6.29-rc3-devel/drivers/md/dm.c 2009-02-05 05:52:19.000000000 +0100
@@ -1375,6 +1375,11 @@ EXPORT_SYMBOL_GPL(dm_put);
static int dm_wait_for_completion(struct mapped_device *md)
{
int r = 0;
+ DECLARE_WAITQUEUE(wait, current);
+
+ dm_unplug_all(md->queue);
+
+ add_wait_queue(&md->wait, &wait);
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
@@ -1392,6 +1397,8 @@ static int dm_wait_for_completion(struct
}
set_current_state(TASK_RUNNING);
+ remove_wait_queue(&md->wait, &wait);
+
return r;
}
@@ -1497,7 +1504,6 @@ static void unlock_fs(struct mapped_devi
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
{
struct dm_table *map = NULL;
- DECLARE_WAITQUEUE(wait, current);
int r = 0;
int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
@@ -1540,20 +1546,14 @@ int dm_suspend(struct mapped_device *md,
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO, &md->flags);
- add_wait_queue(&md->wait, &wait);
up_write(&md->io_lock);
- /* unplug */
- if (map)
- dm_table_unplug_all(map);
-
/*
* Wait for the already-mapped ios to complete.
*/
r = dm_wait_for_completion(md);
down_write(&md->io_lock);
- remove_wait_queue(&md->wait, &wait);
if (noflush)
__merge_pushback_list(md);
--
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