Use the newly introduced ccw request infrastructure to implement
pgid related operations: sense pgid, set pgid and disband pg.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use the newly introduced ccw request infrastructure to implement
the sense id operation.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Reduce code duplication by introducing a central infrastructure to
perform an internal I/O operation on a CCW device.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove the call to BUG() for situations which are unexpected
but do not cause actual problems.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Device recognition needs to be started with the ccw device lock
held to prevent race conditions between I/O starting and interrupt
reception.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Handle verification errors consistently through the existing
callback ccw_device_done to reduce cleanup code duplication.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove the return code from ccw_device_recognition and handle
recognition errors through the existing callback
ccw_device_recog_done to reduce cleanup code duplication.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Print a warning message in case a ccw device enters boxed or
not operational state during online/offline processing.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Introduce a central mechanism for performing delayed ccw device work
to ensure that different types of work do not overwrite each other.
Prioritization ensures that the most important work is always
performed while less important tasks are either obsoleted or repeated
later.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ensure that current and future users of sch->work do not overwrite
each other by introducing a single mechanism for delayed subchannel
work.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Change the initiative to update subchannel-ccw device associations
to the subchannel: when there is an indication that the internal
association no longer reflects the current hardware state, mark
each affected subchannel as requiring attention. Once processing
reaches a subchannel, determine the correct association for that
subchannel at that time and perform the necessary device_move
operations.

This change fixes problems with the previous approach which would
leave devices in an inconsistent state when a new hardware change
occurred while a device_move was already scheduled.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

sch_create_and_recog_new_device() associates a parent subchannel
with its ccw device child even though this is already done by
the subsequently called io_subchannel_recog(). Also make sure
io_subchannel_recog() sets the association under lock.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

io_subchannel_probe() frees memory for sch->private which is later
freed again when io_subchannel_remove() is called. Fix this problem
by removing the cleanup in io_subchannel_probe().
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In a system where the ctrl-alt-del init action initiated by signal
quiesce suspends the machine the quiesce handler override for
_machine_restart, _machine_halt and _machine_power_off needs to be
undone, otherwise the override is still present in the resumed
system. The next shutdown would then load the quiesce state psw
instead of performing the correct shutdown action.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The monreader device driver doesn't set dev->driver_data to NULL after
freeing the corresponding data structure. This leads to a use after
free bug in the freeze/thaw suspend/resume functions after the device
has been opened and closed once. Fix this by clearing dev->driver_data
in the close() function.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

After copying uts->nodename to the static nodename array the static
version isn't necessarily zero termininated, since the size of the
array is one byte too short.
Afterwards doing strncat(data, nodename, strlen(nodename)); may copy
an arbitrary large amount of bytes.
Fix this by getting rid of the static array and using strncat with
proper length limit.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix missing unregister_sysctl_table in case the SCLP doesn't provide
the requested feature. Also simplify the whole error handling while
at it.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If a suspended z/VM guest has been logged off before the resume the
'SET SMSG IUCV' CP command need to be repeated to reenable sending
message via SMSG. This fixes the following error:

HCPMFS057I H4214002 not receiving; SMSG off
Error: non-zero CP response for command 'SMSG H4214002 CMM SHRINK 5010': #57
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix the size of the local buffer and use snprintf to prevent
further miscalculations. Also fix the usage of bitwise vs logic
operations.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When configuring a LUN for use in zfcp, flush the SCSI work to ensure
the SCSI device has been created before returning. This means that a
configuration procedure can run these commands in a script and the
SCSI device is available immediately after the unit_add:

echo 1 > /sys/bus/ccw/drivers/zfcp/0.0.181d/online
echo 0x401040C300000000 > \
        /sys/bus/ccw/drivers/zfcp/0.0.181d/0x500507630313c562/unit_add
lsscsi
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Add HZ since the start_timer function expects jiffies, not seconds.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

After opening a remote port zfcp checks if the WWPN returned in the
PLOGI maches the WWPN of the port that should have been opened. On a
mismatch zfcp assumes that the DID just changed, queries the FC
nameserver and tries again. If the situation persists the erp will
give up.

With this strategy, if the remote port always returns the wrong PLOGI
data, the remote port will not be opened. Introduce a warning, so that
the system administrator knows why the remote port is not being opened
and to have a pointer to investigate the problem on the storage
system.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

For ports, zfcp gets the DID from the FC nameserver and tries to open
the port. If the open succeeds, zfcp compares the WWPN from the
nameserver with the WWPN in the PLOGI payload. In case of a mismatch,
zfcp assumes that the DID of the port just changed and we opened the
wrong port. This means that zfcp has to forget the DID, lookup the DID
again and retry.

This error case had a problem that zfcp forgets the DID, but never
looks up a new one, stalling the ERP in this case. Fix this by
triggering the DID lookup and properly exit from the ERP. The DID
lookup will trigger a new ERP action.

Also ensure when trying to open the port again with the new DID, first
close the open port, even in the NOESC case.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The pointer that is allocated with kmalloc() is passed to strsep()
which modifies it. Later on the modified pointer value will be passed
to kfree. Save the original pointer and pass that one to kfree
instead.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Fix this build error:

	next-20091013 randconfig build on s390x build breaks with

drivers/s390/built-in.o:(.data+0x3354): undefined reference to `sclp_vt220_pm_event_fn'
Reported-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NMichael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use cio_is_console() in io_subchannel_probe to indicate that the
special handling is console specific. As long as there is no other
subchannel for which this might be true, it is misleading to speak
of "early devices". Should more of these devices be introduced,
a cleanup of all console special handling is in order anyway.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

8d65af78 "sysctl: remove "struct file *" argument of ->proc_handler"
removed the struct file argument from all proc_handlers but didn't
change the call home proc handler (or call home was merged later).

So fix this now.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Hans-Joachim Picht <hans@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If the rdc_buffer is above 2G we need indirect addresssing so we have
to use an idaw to give the rdc_buffer to the ccw.
If the rdc_buffer is under 2G nothing changes.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Replace spin_lock with spin_lock_irqsave in dasd_eckd_restore_device.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When setting a channel attached tape online under Linux 2.6.31, the

"vol_id" process from udev hangs in sync_page():
 2 sync_page+144 [0x1dfaac]
 3 __wait_on_bit_lock+194 [0x58c23e]
 4 __lock_page+116 [0x1df9dc]
 5 truncate_inode_pages_range+728 [0x1ed7cc]
 6 __blkdev_put+244 [0x25f738]
 7 __fput+300 [0x229c4c]
 8 filp_close+122 [0x225a3a]

The reason for that is an error in the request queue handling. It can
happen that we fetch a request, but do not process it further because
the number of queued requests exceeds TAPEBLOCK_MIN_REQUEUE.
To fix this, we should call blk_peek_request() instead of
blk_fetch_request() in the while condition and fetch the request in
the loop body afterwards.

This bug was introduced with the patch "block: implement and enforce
request peek/start/fetch" (9934c8c0)
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is a race while re-reading the device characteristics. After
cleaning the memory area a cqr is build which reads the device
characteristics. This may take a rather long time and the device
characteristics structure is zero during this. Now it could be
possible that the block tasklet starts working and a new cqr will be
build. The build_cp command refers to the device characteristics
structure and this may lead into a divide by zero exception.
Fix this by re-reading the device characteristics into a temporary
structur and copy the data to the original structure. Also take the
ccwdev_lock.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Improve the comments for switch cases without a break. This fixes
some warnings of a code checker tool.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Do not shadow earlier symbol.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Allow users to set boxed devices offline. After setting them
offline, the device state will still be boxed.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When a ccw device appears not operational, inform the associated
device driver and act according to the response: if the driver
wants to keep the device, put it into the disconnected state.
If not, or if there is no driver or if the device is not online,
unregister it. This approach is consistent with no-path event
handling.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When there is no path left to a ccw device, inform the associated
device driver and act according to the response: if the driver
wants to keep the device, put it into the disconnected state.
If not, or if there is no driver or if the device is not online,
unregister it.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is a memory leak in /proc/cio_ignore. The iterator is allocated
in cio_ignore_proc_seq_start, but never freed in
cio_ignore_proc_seq_stop, because we cannot use the iterator
that was passed by seqfile. The seqfile interface passes the last
seen iterator to the stop function and not the first one. Since our
next function will return NULL at the end, the iter passed to
cio_ignore_proc_seq_stop is NULL. The original iter has leaked.
The solution is to use seq_open_private.

Found with kmemleak:
unreferenced object 0x1c720580 (size 32):
  comm "head", pid 973, jiffies 4294958302
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000000203154>] kmem_cache_alloc+0x190/0x19c
    [<00000000003fb462>] cio_ignore_proc_seq_start+0x5e/0x128
    [<0000000000231018>] seq_read+0xc8/0x4bc
    [<0000000000273954>] proc_reg_read+0xa8/0xf4
    [<000000000020e3d8>] vfs_read+0xac/0x1a4
    [<000000000020e5c6>] SyS_read+0x52/0xa8
    [<000000000011836e>] sysc_noemu+0x10/0x16
    [<0000004690b7936c>] 0x4690b7936c
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move dev_set_name to when we know that the device will actually be
registered in order to avoid a memory leak if the allocated memory
for the channel path has to be freed.
Signed-off-by: NMichael Ernst <mernst@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix this build failure:
drivers/s390/built-in.o: In function `raw3270_pm_unfreeze':
(.text+0x3ac04): undefined reference to `ccw_device_force_console'
with:
CONFIG_TN3270=y
CONFIG_TN3270_CONSOLE=n
CONFIG_TN3215_CONSOLE=n
Reported-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Running chchp --vary 0 and chccwdev -d on a FCP device with scsi
devices attached can lead to this thread hanging:

================================================================
STACK TRACE FOR TASK: 0x2fbfcc00 (kslowcrw)

 STACK:
 0 schedule+1136 [0x45f99c]
 1 schedule_timeout+534 [0x46054e]
 2 wait_for_common+374 [0x45f442]
 3 blk_execute_rq+160 [0x217a2c]
 4 scsi_execute+278 [0x26daf2]
 5 scsi_execute_req+150 [0x26dc86]
 6 sd_sync_cache+138 [0x28460a]
 7 sd_shutdown+130 [0x28486a]
 8 sd_remove+104 [0x284c84]
 9 __device_release_driver+152 [0x257430]
10 device_release_driver+56 [0x2575c8]
11 bus_remove_device+214 [0x25672a]
12 device_del+352 [0x25456c]
13 __scsi_remove_device+108 [0x272630]
14 scsi_remove_device+66 [0x2726ba]
15 zfcp_ccw_remove+824 [0x335558]
16 ccw_device_remove+62 [0x2b3f2a]
17 __device_release_driver+152 [0x257430]
18 device_release_driver+56 [0x2575c8]
19 bus_remove_device+214 [0x25672a]
20 device_del+352 [0x25456c]
21 ccw_device_unregister+92 [0x2b48c4]
22 io_subchannel_remove+108 [0x2b4950]
23 css_remove+62 [0x2af7ee]
24 __device_release_driver+152 [0x257430]
25 device_release_driver+56 [0x2575c8]
26 bus_remove_device+214 [0x25672a]
27 device_del+352 [0x25456c]
28 device_unregister+38 [0x25464a]
29 css_sch_device_unregister+68 [0x2af97c]
30 ccw_device_call_sch_unregister+78 [0x2b581e]
31 worker_thread+604 [0x69eb0]
32 kthread+154 [0x6ff42]
33 kernel_thread_starter+6 [0x1c952]
================================================================

The problem is that the chchp --vary 0 leads to zfcp first calling
fc_remote_port_delete which blocks all scsi devices on the remote
port. Calling scsi_remove_device later lets the sd driver issue a
SYNCHRONIZE_CACHE command. This command stays on the "stopped" request
requeue because the SCSI device is blocked. Fix this by first removing
the scsi and fc hosts which removes all scsi devices and do not use
scsi_remove_device.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>