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path: root/drivers/s390/block/dasd.c
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2012-04-07Merge branch '3.4-rc1' into android-tegra-nv-3.3-rebasedVarun Wadekar
Change-Id: Ib3b69ffc5ac3e07c9cc44cc49e9142088eec477e Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
2012-01-18[S390] dasd: revalidate server for new pathgroupStefan Haberland
If a pathgroup is established we get an event and have to revalidate the server to propagate supported features like PAV and enable them. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-01-06Merge branches 'vfsmount-guts', 'umode_t' and 'partitions' into ZAl Viro
2012-01-03switch debugfs to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-30[S390] dasd: prevent path verification before resumeStefan Haberland
Mark the device as suspended and delay execution of the path verification worker to prevent mix-up. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] dasd: re-initialize read_conf buffer for retriesStefan Haberland
The buffer for read configuration data has to be initialized with an EBCDIC string to show support for extended UIDs to z/VM. If this read configuration data CQR needs to be retried, the buffer may have changed in between. So re-initialize the buffer to get a correct extended UID under z/VM. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] dasd: wait for terminated requestStefan Haberland
After terminating a request in the dasd_sleep_on_immediatly function, wait for the clear interrupt to be received before starting the new request. This prevents the requests from getting mixed up. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] fix mismatch in summation of I/O IRQ statisticsPeter Oberparleiter
Current IRQ statistics support does not show detail counts for I/O interrupts which are processed internally only. The result is a summation count which is way off such as this one: CPU0 CPU1 CPU2 I/O: 1331 710 442 [...] QAI: 15 16 16 [I/O] QDIO Adapter Interrupt QDI: 1 0 0 [I/O] QDIO Interrupt DAS: 706 645 381 [I/O] DASD C15: 26 10 0 [I/O] 3215 C70: 0 0 0 [I/O] 3270 TAP: 0 0 0 [I/O] Tape VMR: 0 0 0 [I/O] Unit Record Devices LCS: 0 0 0 [I/O] LCS CLW: 0 0 0 [I/O] CLAW CTC: 0 0 0 [I/O] CTC APB: 0 0 0 [I/O] AP Bus Fix this by moving I/O interrupt accounting into the common I/O layer. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-08-03[S390] dasd: use vmalloc for statistics input bufferStefan Weinhuber
The size of the buffer that is used to store DASD statistics input strings depends on the user input. If the input string is to large, the write operation could fail with -ENOMEM. To avoid this, use vmalloc instead of kmalloc. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-07-24[S390] dasd: add enhanced DASD statistics interfaceStefan Weinhuber
This patch extends the DASD statistics to allow for a more detailed analysis of DASD I/O operations. In particular we want the statistics to provide answers to the following questions: - How many requests used a PAV alias? - How many requests used High Performance FICON? - How do read request perform versus write requests? The existing DASD statistics interface has several shortcomings - The interface for global data is a formatted text table in procfs (/proc/dasd/statistics). The layout is meant for human readers and is not to easy to parse. If values get to large for the table layout, they get scaled down. - The statistics which are collected per block device can be accessed via an ioctl interface, which can only be extended by defining a new ioctl. - There is no statistics interface for individual PAV base and alias devices. To overcome theses shortcomings we create a new DASD statistics interface in debugfs. This interface will contain one entry for global data, one per DASD block device, and one per DASD base and alias device. Each file contains the statistic data in easy to parse name/value and name/array pairs. The existing interfaces will remain functional, but they will not be extended. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-10[S390] dasd: prevent IO error during reserve/release loopStefan Haberland
The termination of running CQR caused by reserve/release operations may lead to an IO error if reserve/release is done in a tight loop. Prevent this by increasing the retry counter after termination. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-04-20[S390] dasd: fix race between open and offlineStefan Weinhuber
The dasd_open function uses the private_data pointer of the gendisk to find the dasd_block structure that matches the gendisk. When a DASD device is set offline, we set the private_data pointer of the gendisk to NULL and later remove the dasd_block structure, but there is still a small race window, in which dasd_open could first read a pointer from the private_data field and then try to use it, after the structure has already been freed. To close this race window, we will store a pointer to the dasd_devmap structure of the base device in the private_data field. The devmap entries are not deleted, and we already have proper locking and reference counting in place, so that we can safely get from a devmap pointer to the dasd_device and dasd_block structures of the device. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-05[S390] dasd: Correct retry counter for terminated I/O.Stefan Haberland
In case the DASD driver needs to term a running I/O the retry counter is decreased twice. Remove the unnecessary retry counter decrease in das_term_IO. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: Add support for raw ECKD access.Stefan Haberland
Normal I/O operations through the DASD device driver give only access to the data fields of an ECKD device even for track based I/O. This patch extends the DASD device driver to give access to whole ECKD tracks including count, key and data fields. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: Prevent deadlock during suspend/resume.Stefan Haberland
The freeze callback may set a stop bit so that a worker thread could not start I/O. The discipline specific freeze function waits for the worker to be completed. Set the stop_bit after the discipline specific freeze function has returned and no worker is running. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: Improve handling of stolen DASD reservationStefan Weinhuber
If a DASD device has been reserved by a Linux system, and later this reservation is ‘stolen’ by a second system by means of an unconditional reserve, then the first system receives a notification about this fact. With this patch such an event can be either ignored, as before, or it can be used to let the device fail all I/O request, so that the device will not block anymore. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: do path verification for paths added at runtimeStefan Weinhuber
When a new path is added at runtime, the CIO layer will call the drivers path_event callback. The DASD device driver uses this callback to trigger a path verification for the new path. The driver will use only those paths for I/O, which have been successfully verified. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: add High Performance FICON multitrack supportStefan Weinhuber
Some storage systems support multitrack High Performance FICON requests, which read or write data to more than one track. This patch enables the DASD device driver to generate multitrack High Performance FICON requests. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05[S390] dasd: add support for irq statisticsHeiko Carstens
Add support for DASD I/O interrupt statistics in /proc/interrupts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] dasd: ignore unsolicited interrupts for DIAGStefan Haberland
For the DASD DIAG discipline IO is started through special diagnose calls. Unsolicited interrupts may contain information about the device itself. But this information is not needed because the device is not used directly. Fix the case that an unimplemented dicipline function may be called by ignoring unsolicited interrupts for the DIAG disciplin. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] dasd: fix unsolicited interrupt recognitionStefan Weinhuber
The dasd interrupt handler needs to distinguish solicited from unsolicited interrupts, as unsolicited interrupts may require special handling (e.g. summary unit checks) and solicited interrupts require proper error recovery for the failed I/O request. The interrupt handler needs to check several bit fields in the interrupt response block (irb) to make this distinction. So far our check of the status control bits has not been specific enough, which may lead to a failed request getting just retried instead of the necessary error recovery. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-22Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...
2010-09-26s390/block: kill the big kernel lockArnd Bergmann
The dasd and dcssblk drivers gained the big kernel lock in the recent pushdown from the block layer, but they don't really need it, so remove the calls without a replacement. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org
2010-09-10block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()Tejun Heo
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with -EOPNOTSUPP and blk_queue_ordered() is replaced with simpler blk_queue_flush(). blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a device has write cache and can flush it, it should set REQ_FLUSH. If the device can handle FUA writes, it should also set REQ_FUA. All blk_queue_ordered() users are converted. * ORDERED_DRAIN is mapped to 0 which is the default value. * ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH. * ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: David S. Miller <davem@davemloft.net> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Pierre Ossman <drzeus@drzeus.cx> Cc: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-13[S390] dasd: fix format string typesHeiko Carstens
Get rid of these warnings: drivers/s390/block/dasd.c: In function '__dasd_device_check_expire': drivers/s390/block/dasd.c:1330: warning: format '%i' expects type 'int', but argument 4 has type 'long unsigned int' drivers/s390/block/dasd.c:1337: warning: format '%i' expects type 'int', but argument 4 has type 'long unsigned int' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-08-07block: push down BKL into .open and .releaseArnd Bergmann
The open and release block_device_operations are currently called with the BKL held. In order to change that, we must first make sure that all drivers that currently rely on this have no regressions. This blindly pushes the BKL into all .open and .release operations for all block drivers to prepare for the next step. The drivers can subsequently replace the BKL with their own locks or remove it completely when it can be shown that it is not needed. The functions blkdev_get and blkdev_put are the only remaining users of the big kernel lock in the block layer, besides a few uses in the ioctl code, none of which need to serialize with blkdev_{get,put}. Most of these two functions is also under the protection of bdev->bd_mutex, including the actual calls to ->open and ->release, and the common code does not access any global data structures that need the BKL. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07block: remove q->prepare_flush_fn completelyFUJITA Tomonori
This removes q->prepare_flush_fn completely (changes the blk_queue_ordered API). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-26[S390] dasd: unit check handling during internal cio I/OStefan Haberland
React on unit checks during cio internal I/O. Handle as unsolicited interrupt and advice cio to retry. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-17[S390] dasd: add dynamic pav tolerationStefan Haberland
For base Parallel Access Volume (PAV) there is a fixed mapping of base and alias devices. With dynamic PAV this mapping can be changed so that an alias device is used with another base device. This patch enables the DASD device driver to tolerate dynamic PAV changes. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-12[S390] dasd: fix race between tasklet and dasd_sleep_onStefan Weinhuber
The various dasd_sleep_on functions use a global wait queue when waiting for a cqr. The wait condition checks the status and devlist fields of the cqr to determine if it is safe to continue. This evaluation may return true, although the tasklet has not finished processing of the cqr and the callback function has not been called yet. When the callback is finally called, the data in the cqr may already be invalid. The sleep_on wait condition needs a safe way to determine if the tasklet has finished processing. Use the callback_data field of the cqr to store a token, which is set by the callback function itself. Cc: <stable@kernel.org> Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-04-22[S390] dasd: fix endless loop in erpStefan Haberland
If not enough memory is available to build a new erp request it ended up in an endless loop trying to build erp requests. Fixed the loop to proceed the next request instead. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-03-08[S390] dasd: automatic recognition of read-only devicesStefan Weinhuber
In z/VM it is possible to attach a device as read-only. To prevent unintentional write requests and subsequent I/O errors, we can detect this configuration using the z/VM DIAG 210 interface and set the respective linux block device to read-only as well. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-03-01Merge branch 'for-2.6.34' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.34' of git://git.kernel.dk/linux-2.6-block: (38 commits) block: don't access jiffies when initialising io_context cfq: remove 8 bytes of padding from cfq_rb_root on 64 bit builds block: fix for "Consolidate phys_segment and hw_segment limits" cfq-iosched: quantum check tweak blktrace: perform cleanup after setup error blkdev: fix merge_bvec_fn return value checks cfq-iosched: requests "in flight" vs "in driver" clarification cciss: Fix problem with scatter gather elements in the scsi half of the driver cciss: eliminate unnecessary pointer use in cciss scsi code cciss: do not use void pointer for scsi hba data cciss: factor out scatter gather chain block mapping code cciss: fix scatter gather chain block dma direction kludge cciss: simplify scatter gather code cciss: factor out scatter gather chain block allocation and freeing cciss: detect bad alignment of scsi commands at build time cciss: clarify command list padding calculation cfq-iosched: rethink seeky detection for SSDs cfq-iosched: rework seeky detection block: remove padding from io_context on 64bit builds block: Consolidate phys_segment and hw_segment limits ...
2010-02-26[S390] dasd: correct offline processingStefan Haberland
Flushing the dasd ccw request queue may stop the processing of the block device request queue. Destroy partitions may wait for outstanding requests and thus hang. Swapping dasd_destroy_partitions and dasd_flush_request_queue so that the request queue is empty before dasd_destroy_partitions is called. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] dasd: fix refcounting.Stefan Haberland
The function dasd_device_from_cdev returns a reference to the dasd device and increases the refcount by one. If an exception occurs, the refcount was not decreased in all cases e.g. in dasd_discipline_show. Prevent the offline processing from hang by correcting two functions to decrease the refcount even if an error occured. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] dasd: fix online/offline raceStefan Haberland
Setting a DASD online and offline in quick succession may cause a kernel panic or let the chhccwdev command wait forever. The Online process is split into two parts. After the first part is finished the offline process may be called. This may result in a situation where the second online processing part tries to set the DASD offline as well. Use a mutex to protect online and offline against each other. Also correct some checking. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26block: Consolidate phys_segment and hw_segment limitsMartin K. Petersen
Except for SCSI no device drivers distinguish between physical and hardware segment limits. Consolidate the two into a single segment limit. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-26block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectorsMartin K. Petersen
The block layer calling convention is blk_queue_<limit name>. blk_queue_max_sectors predates this practice, leading to some confusion. Rename the function to appropriately reflect that its intended use is to set max_hw_sectors. Also introduce a temporary wrapper for backwards compability. This can be removed after the merge window is closed. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-01-27[S390] dasd: fix possible NULL pointer errorsStefan Haberland
Fix possible NULL pointer in DASD messages and correct discipline checking. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: remove strings from s390dbfStefan Haberland
Remove strings from s390 debugfeature entries that could lead to a crash when the data is read from dbf because the strings do not exist any more. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: improve error recovery for internal I/OStefan Weinhuber
Most of the error conditions reported by a FICON storage server indicate situations which can be recovered. Sometimes the host just needs to retry an I/O request, but sometimes the recovery is more complex and requires the device driver to wait, choose a different path, etc. The DASD device driver has a fully featured error recovery for normal block layer I/O, but not for internal I/O request which are for example used during the device bring up. This can lead to situations where the IPL of a system fails because DASD devices are not properly recognized. This patch will extend the internal I/O handling to use the existing error recovery procedures. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: remove dead codeChristian Borntraeger
the todclk.h header file is dead code. Remove it. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: split PGID settings and statusPeter Oberparleiter
Split setting (driver wants feature enabled) and status (feature setup was successful) for PGID related ccw device features so that setup errors can be detected. Previously, incorrectly handled setup errors could in rare cases lead to erratic I/O behavior and permanently unusuable devices. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-10-14[S390] dasd: use idal for device characteristicsStefan Haberland
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: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-10-06[S390] dasd: fix race condition in resume codeStefan Haberland
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: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-22const: make block_device_operations constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-11[S390] dasd: optimize cpu usage in goodcaseStefan Haberland
remove unnecessary dbf call, remove string operations for magic Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] dasd: fail requests when device state is less then readyStefan Weinhuber
A DASD device that is not ready or online has no defined disk layout, so all requests that arrive in such a state need to be returned as failed. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>