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path: root/drivers/s390/char/vmur.h
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2008-04-17[S390] vmur: Use wait queue instead of mutex to serialize openFrank Munzert
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>
2007-08-22[S390] vmur: fix reference counting for vmur device structureMichael Holzheu
When a vmur device is removed due to a detach of the device, currently the ur device structure is freed. Unfortunately it can happen, that there is still a user of the device structure, when the character device is open during the detach process. To fix this, reference counting for the vmur structure is introduced. In addition to that, the online, offline, probe and remove functions are serialized now using a global mutex. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2007-08-10[S390] vmur: add "top of queue" sanity check for reader openMichael Holzheu
If the z/VM reader is already open, it can happen that after opening the Linux reader device, not the topmost file is processed. According the semantics of the Linux z/VM unit record device driver, always the topmost file has to be processed. With this fix an error is returned if that is not the case. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-08-10[S390] vmur: reject open on z/VM reader files with status HOLDMichael Holzheu
If a reader file with HOLD status is at the top of the reader queue, currently all read requests will return data of the second file in the queue. But the semantics of vmur is that always the topmost file is read. With this fix -EPERM is returned on open, if the topmost reader file is in HOLD status. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-07-17[S390] z/VM unit record device driverFrank Munzert
z/VM Unit record character device driver to access VM reader, punch, and printer. Signed-off-by: Frank Munzert <munzert@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>