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| author | Frank Munzert <munzert@de.ibm.com> | 2008-04-17 07:46:06 +0200 |
|---|---|---|
| committer | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-04-17 07:46:59 +0200 |
| commit | a695f16729e00995fe72baf0e8bee4bf9c232ae0 (patch) | |
| tree | 2fddf1722972564e33eedbedf9010bdd9735a74d /drivers/s390/char/vmur.h | |
| parent | [S390] tape: duplicate sysfs filename when setting tape device online (diff) | |
| download | linux-a695f16729e00995fe72baf0e8bee4bf9c232ae0.tar.xz linux-a695f16729e00995fe72baf0e8bee4bf9c232ae0.zip | |
[S390] vmur: Use wait queue instead of mutex to serialize open
If user space opens a unit record device node then vmur is leaving the kernel
with lock open_mutex still held to prevent other processes from opening the
device simultaneously. This causes lockdep to complain about a lock held when
returning to user space.
Now the mutex is replaced by a wait queue to serialize device open.
Signed-off-by: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Diffstat (limited to 'drivers/s390/char/vmur.h')
| -rw-r--r-- | drivers/s390/char/vmur.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/s390/char/vmur.h b/drivers/s390/char/vmur.h index fa959644735a..fa320ad4593d 100644 --- a/drivers/s390/char/vmur.h +++ b/drivers/s390/char/vmur.h @@ -62,7 +62,6 @@ struct file_control_block { struct urdev { struct ccw_device *cdev; /* Backpointer to ccw device */ struct mutex io_mutex; /* Serialises device IO */ - struct mutex open_mutex; /* Serialises access to device */ struct completion *io_done; /* do_ur_io waits; irq completes */ struct device *device; struct cdev *char_device; @@ -71,6 +70,9 @@ struct urdev { int class; /* VM device class */ int io_request_rc; /* return code from I/O request */ atomic_t ref_count; /* reference counter */ + wait_queue_head_t wait; /* wait queue to serialize open */ + int open_flag; /* "urdev is open" flag */ + spinlock_t open_lock; /* serialize critical sections */ }; /* |