diff options
| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-07-10 10:05:50 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-07-11 13:41:57 -0700 |
| commit | ffa423fb3251f8737303ffc3b0659e86e501808e (patch) | |
| tree | 0d93e56751fc63134f41f2bbb5e38963c6281aa4 | |
| parent | 6a146f3a5894b751cef16feb3d7903e45e3c445c (diff) | |
| download | linux-ffa423fb3251f8737303ffc3b0659e86e501808e.tar.bz2 | |
tap: convert a mutex to a spinlock
We are not allowed to block on the RCU reader side, so can't
just hold the mutex as before. As a quick fix, convert it to
a spinlock.
Fixes: d9f1f61c0801 ("tap: Extending tap device create/destroy APIs")
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/tap.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 9af3239d6ad5..3570c7576993 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -106,7 +106,7 @@ struct major_info { struct rcu_head rcu; dev_t major; struct idr minor_idr; - struct mutex minor_lock; + spinlock_t minor_lock; const char *device_name; struct list_head next; }; @@ -416,15 +416,15 @@ int tap_get_minor(dev_t major, struct tap_dev *tap) goto unlock; } - mutex_lock(&tap_major->minor_lock); - retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_KERNEL); + spin_lock(&tap_major->minor_lock); + retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_ATOMIC); if (retval >= 0) { tap->minor = retval; } else if (retval == -ENOSPC) { netdev_err(tap->dev, "Too many tap devices\n"); retval = -EINVAL; } - mutex_unlock(&tap_major->minor_lock); + spin_unlock(&tap_major->minor_lock); unlock: rcu_read_unlock(); @@ -442,12 +442,12 @@ void tap_free_minor(dev_t major, struct tap_dev *tap) goto unlock; } - mutex_lock(&tap_major->minor_lock); + spin_lock(&tap_major->minor_lock); if (tap->minor) { idr_remove(&tap_major->minor_idr, tap->minor); tap->minor = 0; } - mutex_unlock(&tap_major->minor_lock); + spin_unlock(&tap_major->minor_lock); unlock: rcu_read_unlock(); @@ -467,13 +467,13 @@ static struct tap_dev *dev_get_by_tap_file(int major, int minor) goto unlock; } - mutex_lock(&tap_major->minor_lock); + spin_lock(&tap_major->minor_lock); tap = idr_find(&tap_major->minor_idr, minor); if (tap) { dev = tap->dev; dev_hold(dev); } - mutex_unlock(&tap_major->minor_lock); + spin_unlock(&tap_major->minor_lock); unlock: rcu_read_unlock(); @@ -1244,7 +1244,7 @@ static int tap_list_add(dev_t major, const char *device_name) tap_major->major = MAJOR(major); idr_init(&tap_major->minor_idr); - mutex_init(&tap_major->minor_lock); + spin_lock_init(&tap_major->minor_lock); tap_major->device_name = device_name; |