[patch] md: locking fix

From: Ingo Molnar
Date: Wed Apr 19 2006 - 05:48:22 EST


- fix mddev_lock() usage bugs in md_attr_show() and md_attr_store().
[they did not anticipate the possibility of getting a signal]

- remove mddev_lock_uninterruptible() [unused]

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

----

drivers/md/md.c | 24 ++++++++++++------------
1 files changed, 12 insertions(+), 12 deletions(-)

Index: linux/drivers/md/md.c
===================================================================
--- linux.orig/drivers/md/md.c
+++ linux/drivers/md/md.c
@@ -279,11 +279,6 @@ static inline int mddev_lock(mddev_t * m
return mutex_lock_interruptible(&mddev->reconfig_mutex);
}

-static inline void mddev_lock_uninterruptible(mddev_t * mddev)
-{
- mutex_lock(&mddev->reconfig_mutex);
-}
-
static inline int mddev_trylock(mddev_t * mddev)
{
return mutex_trylock(&mddev->reconfig_mutex);
@@ -2458,9 +2453,11 @@ md_attr_show(struct kobject *kobj, struc

if (!entry->show)
return -EIO;
- mddev_lock(mddev);
- rv = entry->show(mddev, page);
- mddev_unlock(mddev);
+ rv = mddev_lock(mddev);
+ if (!rv) {
+ rv = entry->show(mddev, page);
+ mddev_unlock(mddev);
+ }
return rv;
}

@@ -2474,9 +2471,11 @@ md_attr_store(struct kobject *kobj, stru

if (!entry->store)
return -EIO;
- mddev_lock(mddev);
- rv = entry->store(mddev, page, length);
- mddev_unlock(mddev);
+ rv = mddev_lock(mddev);
+ if (!rv) {
+ rv = entry->store(mddev, page, length);
+ mddev_unlock(mddev);
+ }
return rv;
}

@@ -4341,8 +4340,9 @@ static int md_seq_show(struct seq_file *
return 0;
}

- if (mddev_lock(mddev)!=0)
+ if (mddev_lock(mddev))
return -EINTR;
+
if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
seq_printf(seq, "%s : %sactive", mdname(mddev),
mddev->pers ? "" : "in");
-
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