Signed-off-by: NJonathan Corbet <corbet@lwn.net>

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: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NJan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

There are several s390 diagnose calls, which must be executed below the
2GB memory boundary. In order to enforce this, those diagnoses must be
compiled into the kernel. Currently diag 14 can be called within the
vmur kernel module from addresses above 2GB. This leads to specification
exceptions. This patch moves diag10, diag14 and diag210 into the new
diag.c file.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

If memory buffers above 2GB are used, diagnose 14 raises a specification
exception. This fix ensures that buffer allocation is done below the 2GB
boundary.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

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: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
000000000ff9fb08 000000000ff9fb18 0000000000000002 0000000000000000
000000000ff9fbb8 000000000ff9fb30 000000000ff9fb30 0000000000104198
0000000000000000 0000000000000002 0000000000000000 0000000000000000
000000000ff9fb18 000000000000000c 000000000ff9fb18 000000000ff9fb88
0000000000448db0 0000000000104198 000000000ff9fb18 000000000ff9fb68
Call Trace:
([<00000000001040ea>] show_trace+0x12e/0x170)
 [<00000000001041f2>] show_stack+0xc6/0xf8
 [<0000000000104252>] dump_stack+0x2e/0x3c
 [<0000000000155f9c>] __lock_acquire+0x460/0x1048
 [<0000000000156c16>] lock_acquire+0x92/0xb8
 [<000000000043f406>] _spin_lock_irqsave+0x62/0x80
 [<0000000000121382>] complete+0x32/0x78
 [<000000001082b468>] ur_int_handler+0xc8/0xec [vmur]
 [<0000000000313216>] ccw_device_call_handler+0xae/0xd4
 [<0000000000310da4>] ccw_device_irq+0x5c/0x130
 [<0000000000312c84>] io_subchannel_irq+0x8c/0x118
 [<000000000030a88c>] do_IRQ+0x16c/0x194
 [<0000000000111a62>] io_no_vtime+0x16/0x1c
 [<0000000080001394>] 0x80001394
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

vmur allocates one contiguous kernel buffer to copy user data when creating
ccw programs for punch or printer. If big block sizes are used, under memory
pressure it can happen, that we do not get memory in one chunk. Now we
allocate memory for each single record to avoid high order allocations.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Record length of spool file must be only stored in 1st SPLINK record
Signed-off-by: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

z/VM Unit record character device driver to access VM reader, punch,
and printer.
Signed-off-by: NFrank Munzert <munzert@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>