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* s390/dasd: avoid undefined behaviourChristian Borntraeger2016-10-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the mdc value can be quite big (like 65535), so we are in undefined territory when doing the multiplication with the (also signed) FCX_MAX_DATA_FACTOR as outlined by UBSAN: UBSAN: Undefined behaviour in drivers/s390/block/dasd_eckd.c:1678:14 signed integer overflow: 65535 * 65536 cannot be represented in type 'int' CPU: 5 PID: 183 Comm: kworker/u512:1 Not tainted 4.7.0+ #150 Workqueue: events_unbound async_run_entry_fn 000000fb8b59f900 000000fb8b59f990 0000000000000002 0000000000000000 000000fb8b59fa30 000000fb8b59f9a8 000000fb8b59f9a8 000000000011732e 00000000000000a4 0000000000a309e2 0000000000a4c072 000000000000000b 000000fb8b59f9f0 000000fb8b59f990 0000000000000000 0000000000000000 0400000000d83238 000000000011732e 000000fb8b59f990 000000fb8b59f9f0 Call Trace: ([<0000000000117260>] show_trace+0x98/0xa8) ([<00000000001172e0>] show_stack+0x70/0xf0) ([<000000000053ac96>] dump_stack+0x86/0xb8) ([<000000000057f5f8>] ubsan_epilogue+0x28/0x70) ([<000000000057fe9e>] handle_overflow+0xde/0xf0) ([<00000000006c322a>] dasd_eckd_check_characteristics+0x50a/0x550) ([<00000000006b42ca>] dasd_generic_set_online+0xba/0x380) ([<0000000000693d82>] ccw_device_set_online+0x192/0x550) ([<00000000006ac1ae>] dasd_generic_auto_online+0x2e/0x70) ([<0000000000172130>] async_run_entry_fn+0x70/0x270) ([<0000000000165a72>] process_one_work+0x26a/0x638) ([<0000000000165e8a>] worker_thread+0x4a/0x658) ([<000000000016dd9c>] kthread+0x10c/0x110) ([<00000000008963ae>] kernel_thread_starter+0x6/0xc) ([<00000000008963a8>] kernel_thread_starter+0x0/0xc) As this is a runtime value there is actually no risk of any sane compiler to detect and (ab)use this undefinedness, but let's make the multiplication defined by making mdc unsigned. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: add missing \n to end of dev_err messagesColin Ian King2016-09-281-2/+2
| | | | | | | Trival fix, dev_err messages are missing a \n, so add it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: make query host access interruptibleStefan Haberland2016-09-261-1/+1
| | | | | | | | | | If the DASD device gets blocked for any reason, e.g. because it is reserved somewhere, the host_access_count sysfs entry or the host_access_list debugfs entry may sleep forever. Make it interruptible so that userspace can use ^C to abort the operation. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix panic during offline processingStefan Haberland2016-09-263-10/+18
| | | | | | | | | | | | | | | | | | | A DASD device consists of the device itself and a discipline with a corresponding private structure. These fields are set up during online processing right after the device is created and before it is processed by the state machine and made available for I/O. During offline processing the discipline pointer and the private data gets freed within the state machine and without protection of the existing reference count. This might lead to a kernel panic because a function might have taken a device reference and accesses the discipline pointer and/or private data of the device while this is already freed. Fix by freeing the discipline pointer and the private data after ensuring that there is no reference to the device left. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix hanging offline processingStefan Haberland2016-09-261-0/+9
| | | | | | | | | | | | | | | Internal I/O is processed by the _sleep_on_function which might wait for a device to get operational. During offline processing this will never happen and therefore the refcount of the device will not drop to zero and the offline processing blocks as well. Fix by letting requests fail in the _sleep_on function during offline processing. No further handling of the requests is necessary since this is internal I/O and the device is thrown away afterwards. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: add missing KOBJ_CHANGE event for unformatted devicesStefan Haberland2016-09-201-0/+4
| | | | | | | | | | The DASD device driver throws change events for the DASD blockdevice after the online processing is done so that udev rules can take actions after it. The change event was missing for unformatted devices. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix failing CUIR assignment under LPARStefan Haberland2016-08-111-0/+10
| | | | | | | | | | | | | On LPAR the read message buffer command should be executed on the path it was received on otherwise there is a chance that the CUIR assignment might be faulty and the wrong channel path is set online/offline. Fix by setting the path mask accordingly. On z/VM we might not be able to do I/O on this path but there it does not matter on which path the read message buffer command is executed. Therefor implement a retry with an open path mask. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
* s390/dasd: fix hanging device after clear subchannelStefan Haberland2016-08-101-1/+9
| | | | | | | | | | | | | | | | When a device is in a status where CIO has killed all I/O by itself the interrupt for a clear request may not contain an irb to determine the clear function. Instead it contains an error pointer -EIO. This was ignored by the DASD int_handler leading to a hanging device waiting for a clear interrupt. Handle -EIO error pointer correctly for requests that are clear pending and treat the clear as successful. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge tag 'libnvdimm-for-4.8' of ↵Linus Torvalds2016-07-291-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: - Replace pcommit with ADR / directed-flushing. The pcommit instruction, which has not shipped on any product, is deprecated. Instead, the requirement is that platforms implement either ADR, or provide one or more flush addresses per nvdimm. ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers to the memory controller on a power-fail event. Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure: "Flush Hint Address Structure". A flush hint is an mmio address that when written and fenced assures that all previous posted writes targeting a given dimm have been flushed to media. - On-demand ARS (address range scrub). Linux uses the results of the ACPI ARS commands to track bad blocks in pmem devices. When latent errors are detected we re-scrub the media to refresh the bad block list, userspace can also request a re-scrub at any time. - Support for the Microsoft DSM (device specific method) command format. - Support for EDK2/OVMF virtual disk device memory ranges. - Various fixes and cleanups across the subsystem. * tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits) libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register" nfit: do an ARS scrub on hitting a latent media error nfit: move to nfit/ sub-directory nfit, libnvdimm: allow an ARS scrub to be triggered on demand libnvdimm: register nvdimm_bus devices with an nd_bus driver pmem: clarify a debug print in pmem_clear_poison x86/insn: remove pcommit Revert "KVM: x86: add pcommit support" nfit, tools/testing/nvdimm/: unify shutdown paths libnvdimm: move ->module to struct nvdimm_bus_descriptor nfit: cleanup acpi_nfit_init calling convention nfit: fix _FIT evaluation memory leak + use after free tools/testing/nvdimm: add manufacturing_{date|location} dimm properties tools/testing/nvdimm: add virtual ramdisk range acpi, nfit: treat virtual ramdisk SPA as pmem region pmem: kill __pmem address space pmem: kill wmb_pmem() libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes fs/dax: remove wmb_pmem() libnvdimm, pmem: flush posted-write queues on shutdown ...
| * pmem: kill __pmem address spaceDan Williams2016-07-131-3/+3
| | | | | | | | | | | | | | | | | | | | The __pmem address space was meant to annotate codepaths that touch persistent memory and need to coordinate a call to wmb_pmem(). Now that wmb_pmem() is gone, there is little need to keep this annotation. Cc: Christoph Hellwig <hch@lst.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds2016-07-273-6/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block driver updates from Jens Axboe: "This branch also contains core changes. I've come to the conclusion that from 4.9 and forward, I'll be doing just a single branch. We often have dependencies between core and drivers, and it's hard to always split them up appropriately without pulling core into drivers when that happens. That said, this contains: - separate secure erase type for the core block layer, from Christoph. - set of discard fixes, from Christoph. - bio shrinking fixes from Christoph, as a followup up to the op/flags change in the core branch. - map and append request fixes from Christoph. - NVMeF (NVMe over Fabrics) code from Christoph. This is pretty exciting! - nvme-loop fixes from Arnd. - removal of ->driverfs_dev from Dan, after providing a device_add_disk() helper. - bcache fixes from Bhaktipriya and Yijing. - cdrom subchannel read fix from Vchannaiah. - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier. - set of drbd updates and fixes from Fabian, Lars, and Philipp. - mg_disk error path fix from Bart. - user notification for failed device add for loop, from Minfei. - NVMe in general: + NVMe delay quirk from Guilherme. + SR-IOV support and command retry limits from Keith. + fix for memory-less NUMA node from Masayoshi. + use UINT_MAX for discard sectors, from Minfei. + cancel IO fixes from Ming. + don't allocate unused major, from Neil. + error code fixup from Dan. + use constants for PSDT/FUSE from James. + variable init fix from Jay. + fabrics fixes from Ming, Sagi, and Wei. + various fixes" * 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits) nvme/pci: Provide SR-IOV support nvme: initialize variable before logical OR'ing it block: unexport various bio mapping helpers scsi/osd: open code blk_make_request target: stop using blk_make_request block: simplify and export blk_rq_append_bio block: ensure bios return from blk_get_request are properly initialized virtio_blk: use blk_rq_map_kern memstick: don't allow REQ_TYPE_BLOCK_PC requests block: shrink bio size again block: simplify and cleanup bvec pool handling block: get rid of bio_rw and READA block: don't ignore -EOPNOTSUPP blkdev_issue_write_same block: introduce BLKDEV_DISCARD_ZERO to fix zeroout NVMe: don't allocate unused nvme_major nvme: avoid crashes when node 0 is memoryless node. nvme: Limit command retries loop: Make user notify for adding loop device failed nvme-loop: fix nvme-loop Kconfig dependencies nvmet: fix return value check in nvmet_subsys_alloc() ...
| * | block: convert to device_add_disk()Dan Williams2016-06-273-6/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For block drivers that specify a parent device, convert them to use device_add_disk(). This conversion was done with the following semantic patch: @@ struct gendisk *disk; expression E; @@ - disk->driverfs_dev = E; ... - add_disk(disk); + device_add_disk(E, disk); @@ struct gendisk *disk; expression E1, E2; @@ - disk->driverfs_dev = E1; ... E2 = disk; ... - add_disk(E2); + device_add_disk(E1, E2); ...plus some manual fixups for a few missed conversions. Cc: Jens Axboe <axboe@fb.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-blockLinus Torvalds2016-07-271-0/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: - the big change is the cleanup from Mike Christie, cleaning up our uses of command types and modified flags. This is what will throw some merge conflicts - regression fix for the above for btrfs, from Vincent - following up to the above, better packing of struct request from Christoph - a 2038 fix for blktrace from Arnd - a few trivial/spelling fixes from Bart Van Assche - a front merge check fix from Damien, which could cause issues on SMR drives - Atari partition fix from Gabriel - convert cfq to highres timers, since jiffies isn't granular enough for some devices these days. From Jan and Jeff - CFQ priority boost fix idle classes, from me - cleanup series from Ming, improving our bio/bvec iteration - a direct issue fix for blk-mq from Omar - fix for plug merging not involving the IO scheduler, like we do for other types of merges. From Tahsin - expose DAX type internally and through sysfs. From Toshi and Yigal * 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits) block: Fix front merge check block: do not merge requests without consulting with io scheduler block: Fix spelling in a source code comment block: expose QUEUE_FLAG_DAX in sysfs block: add QUEUE_FLAG_DAX for devices to advertise their DAX support Btrfs: fix comparison in __btrfs_map_block() block: atari: Return early for unsupported sector size Doc: block: Fix a typo in queue-sysfs.txt cfq-iosched: Charge at least 1 jiffie instead of 1 ns cfq-iosched: Fix regression in bonnie++ rewrite performance cfq-iosched: Convert slice_resid from u64 to s64 block: Convert fifo_time from ulong to u64 blktrace: avoid using timespec block/blk-cgroup.c: Declare local symbols static block/bio-integrity.c: Add #include "blk.h" block/partition-generic.c: Remove a set-but-not-used variable block: bio: kill BIO_MAX_SIZE cfq-iosched: temporarily boost queue priority for idle classes block: drbd: avoid to use BIO_MAX_SIZE block: bio: remove BIO_MAX_SECTORS ...
| * | block: add QUEUE_FLAG_DAX for devices to advertise their DAX supportToshi Kani2016-07-211-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, presence of direct_access() in block_device_operations indicates support of DAX on its block device. Because block_device_operations is instantiated with 'const', this DAX capablity may not be enabled conditinally. In preparation for supporting DAX to device-mapper devices, add QUEUE_FLAG_DAX to request_queue flags to advertise their DAX support. This will allow to set the DAX capability based on how mapped device is composed. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: <linux-s390@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* / s390/time: LPAR offset handlingMartin Schwidefsky2016-06-131-2/+2
|/ | | | | | | | | | | | | | | It is possible to specify a user offset for the TOD clock, e.g. +2 hours. The TOD clock will carry this offset even if the clock is synchronized with STP. This makes the time stamps acquired with get_sync_clock() useless as another LPAR migth use a different TOD offset. Use the PTFF instrution to get the TOD epoch difference and subtract it from the TOD clock value to get a physical timestamp. As the epoch difference contains the sync check delta as well the LPAR offset value to the physical clock needs to be refreshed after each clock synchronization. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge tag 'dax-misc-for-4.7' of ↵Linus Torvalds2016-05-271-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull misc DAX updates from Vishal Verma: "DAX error handling for 4.7 - Until now, dax has been disabled if media errors were found on any device. This enables the use of DAX in the presence of these errors by making all sector-aligned zeroing go through the driver. - The driver (already) has the ability to clear errors on writes that are sent through the block layer using 'DSMs' defined in ACPI 6.1. Other misc changes: - When mounting DAX filesystems, check to make sure the partition is page aligned. This is a requirement for DAX, and previously, we allowed such unaligned mounts to succeed, but subsequent reads/writes would fail. - Misc/cleanup fixes from Jan that remove unused code from DAX related to zeroing, writeback, and some size checks" * tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: fix a comment in dax_zero_page_range and dax_truncate_page dax: for truncate/hole-punch, do zeroing through the driver if possible dax: export a low-level __dax_zero_page_range helper dax: use sb_issue_zerout instead of calling dax_clear_sectors dax: enable dax in the presence of known media errors (badblocks) dax: fallback from pmd to pte on error block: Update blkdev_dax_capable() for consistency xfs: Add alignment check for DAX mount ext2: Add alignment check for DAX mount ext4: Add alignment check for DAX mount block: Add bdev_dax_supported() for dax mount checks block: Add vfs_msg() interface dax: Remove redundant inode size checks dax: Remove pointless writeback from dax_do_io() dax: Remove zeroing from dax_io() dax: Remove dead zeroing code from fault handlers ext2: Avoid DAX zeroing to corrupt data ext2: Fix block zeroing in ext2_get_blocks() for DAX dax: Remove complete_unwritten argument DAX: move RADIX_DAX_ definitions to dax.c
| * dax: enable dax in the presence of known media errors (badblocks)Dan Williams2016-05-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1/ If a mapping overlaps a bad sector fail the request. 2/ Do not opportunistically report more dax-capable capacity than is requested when errors present. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> [vishal: fix a conflict with system RAM collision patches] [vishal: add a 'size' parameter to ->direct_access] [vishal: fix a conflict with DAX alignment check patches] Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
* | s390/dasd: Add new ioctl BIODASDCHECKFMTJan Höppner2016-04-156-23/+644
| | | | | | | | | | | | | | | | | | | | | | | | | | Implement new DASD IOCTL BIODASDCHECKFMT to check a range of tracks on a DASD volume for correct formatting. The following characteristics are checked: - Block size - ECKD key length - ECKD record ID - Number of records per track Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/dasd: add query host access to volume supportStefan Haberland2016-04-155-1/+282
| | | | | | | | | | | | | | | | | | | | | | With this feature, applications can query if a DASD volume is online to another operating system instances by checking the online status of all attached hosts from the storage server. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/dcssblk: fix possible deadlock in remove vs. per-device attributesGerald Schaefer2016-04-151-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dcssblk_remove_store() holds the dcssblk_devices_sem semaphore while calling device_unregister(), which in turn tries to acquire the kernfs kn->dev_map rwsem for the device sysfs subtree. The same rwsem is also acquired when using the per-device sysfs attributes in the device sub-tree, and the attribute handlers then also acquire the dcssblk_devices_sem. This can lead to a deadlock when removing a DCSS while concurrently reading from / writing to one of its sysfs attributes. The following lockdep warning hinted towards the issue (CPU0 = dcssblk_remove_store, CPU1 = dcssblk_shared_store): [ 76.496047] Possible unsafe locking scenario: [ 76.496054] CPU0 CPU1 [ 76.496059] ---- ---- [ 76.496087] lock(&dcssblk_devices_sem); [ 76.496090] lock(s_active#175); [ 76.496106] lock(&dcssblk_devices_sem); [ 76.496110] lock(s_active#175); [ 76.496115] *** DEADLOCK *** Fix this by releasing the dcssblk_devices_sem semaphore, which only protects internal DCSS data, before calling device_unregister(). Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/scm_blk: fix deadlock for requests != REQ_TYPE_FSSebastian Ott2016-04-011-1/+1
|/ | | | | | | | | | | When we refuse a non REQ_TYPE_FS request in the build request function we already hold the queue lock. Thus we must not call blk_end_request_all but __blk_end_request_all. Reported-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Fixes: de9587a ('s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS') Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: reorder lcu and device lockStefan Haberland2016-03-174-183/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reorder lcu and device lock to get rid of the error-prone trylock mechanism. The locking order is lcu lock -> device lock. This protects against changes to the lcu device lists and enables us to iterate over the devices, take the cdev lock and make changes to the device structures. The complicated part is the summary unit check handler that gets an interrupt on one device of the lcu that leads to structural changes of the whole lcu itself. This work needs to be done even if devices on the lcu disappear. So a device independent worker is used. The old approach tried to update some lcu structures and set up the lcu worker in the interrupt context with the device lock held. But this forced the lock order "cdev lock -> lcu lock" that made it hard to have the lcu lock held and iterate over all devices and change them. The new approach is to schedule a device specific worker that gets out of the interrupt context and rid of the device lock for summary unit checks. This worker is able to take the lcu lock and schedule the lcu worker that updates all devices. The time between interrupt and worker execution is no problem because the devices in the lcu reject all I/O in this time with an appropriate error. The dasd driver can deal with this situation and re-drive the I/O later on. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2016-03-1610-388/+389
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: - Add the CPU id for the new z13s machine - Add a s390 specific XOR template for RAID-5 checksumming based on the XC instruction. Remove all other alternatives, XC is always faster - The merge of our four different stack tracers into a single one - Tidy up the code related to page tables, several large inline functions are now out-of-line. Bloat-o-meter reports ~11K text size reduction - A binary interface for the priviledged CLP instruction to retrieve the hardware view of the installed PCI functions - Improvements for the dasd format code - Bug fixes and cleanups * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (31 commits) s390/pci: enforce fmb page boundary rule s390: fix floating pointer register corruption (again) s390/cpumf: add missing lpp magic initialization s390: Fix misspellings in comments s390/mm: split arch/s390/mm/pgtable.c s390/mm: uninline pmdp_xxx functions from pgtable.h s390/mm: uninline ptep_xxx functions from pgtable.h s390/pci: add ioctl interface for CLP s390: Use pr_warn instead of pr_warning s390/dasd: remove casts to dasd_*_private s390/dasd: Refactor dasd format functions s390/dasd: Simplify code in format logic s390/dasd: Improve dasd format code s390/percpu: remove this_cpu_cmpxchg_double_4 s390/cpumf: Improve guest detection heuristics s390/fault: merge report_user_fault implementations s390/dis: use correct escape sequence for '%' character s390/kvm: simplify set_guest_storage_key s390/oprofile: add z13/z13s model numbers s390: add z13s model number to z13 elf platform ...
| * s390: Use pr_warn instead of pr_warningJoe Perches2016-03-076-36/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the uses of pr_warning to pr_warn so there are fewer uses of the old pr_warning. Miscellanea: o Align arguments o Coalesce formats Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/dasd: remove casts to dasd_*_privateSebastian Ott2016-03-075-181/+106
| | | | | | | | | | | | | | | | | | | | Convert dasd_device.private to be a void pointer to get rid of a lot of explicit casts. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/dasd: Refactor dasd format functionsJan Höppner2016-03-071-12/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prepare for new format checking function by renaming functions and moving reusable code to separate functions: - Move sanity checks into a new function and make it reusable. - Move common format code to a new function called dasd_eckd_format_process_data. - Create the generic function dasd_eckd_format_build_ccw_req, which itself will then decide what ccw request is being built according to the input data. (with upcoming functionality). Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/dasd: Simplify code in format logicJan Höppner2016-03-071-27/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, dasd_format is calling the format logic of a DASD discipline with PAV enabled. If that fails with an error code of -EAGAIN the value of retries is decremented and the discipline function is called with PAV turned off. The loop is supposed to try this up to 255 times until success. However, -EAGAIN can only occur once here and therefore the loop will never reach the 255 retries. So, replace the unnecessarily complicated loop logic and simply try again without PAV enabled in case of an -EAGAIN error. Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/dasd: Improve dasd format codeJan Höppner2016-03-072-58/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | - Make sure a calling function can rely on data in fdata by resetting to its initial values - Move special treatment for track 0 and 1 to dasd_eckd_build_format - Replace dangerous backward goto with a loop logic - Add define for number that specifies the maximum amount of CCWs per request and is used for format_step calculation - Remove unused variable Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * s390/dasd: fix incorrect locking order for LCU device add/removeStefan Haberland2016-02-231-83/+152
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The correct lock order for LCU lock and cdev lock is to take the cdev lock first and afterwards the LCU lock. This is caused by the fact that LCU functions are called in an interrupt context with the cdev lock implicitly hold by CIO. To assure the right locking order but also be able to iterate over devices in a LCU introduce a trylock block that can be called with the device lock for one device hold and then takes the LCU lock and try to lock all devices accounted to this LCU. Afterwards all devices and the LCU itself are locked. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | s390/dasd: fix diag 0x250 inline assemblyHeiko Carstens2016-03-021-2/+7
|/ | | | | | | | | | | | | | | | | | | | git commit 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") added function calls to gather diagnose statistics. In case of the dasd diag driver the function call was added between a register asm statement which initialized register r2 and the inline assembly itself. The function call clobbers the contents of register r2 and therefore the diag 0x250 call behaves in a more or less random way. Fix this by extracting the function call into a separate function like we do everywhere else. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Cc: <stable@vger.kernel.org> # 4.4+ Reported-and-tested-by: Stefan Haberland <sth@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix performance dropStefan Haberland2016-02-171-0/+1
| | | | | | | | | | | | | Commit ca369d51b ("sd: Fix device-imposed transfer length limits") introduced a new queue limit max_dev_sectors which limits the maximum sectors for requests. The default value leads to small dasd requests and therefor to a performance drop. Set the max_dev_sectors value to the same value as the max_hw_sectors to use the maximum available request size for DASD devices. Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix refcount for PAV reassignmentStefan Haberland2016-02-111-5/+16
| | | | | | | | | | Add refcount to the DASD device when a summary unit check worker is scheduled. This prevents that the device is set offline with worker in place. Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: prevent incorrect length error under z/VM after PAV changesStefan Haberland2016-02-111-1/+1
| | | | | | | | | | | | The channel checks the specified length and the provided amount of data for CCWs and provides an incorrect length error if the size does not match. Under z/VM with simulation activated the length may get changed. Having the suppress length indication bit set is stated as good CCW coding practice and avoids errors under z/VM. Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* mm, dax, pmem: introduce pfn_tDan Williams2016-01-161-6/+5
| | | | | | | | | | | | | | | | | | | | | | | For the purpose of communicating the optional presence of a 'struct page' for the pfn returned from ->direct_access(), introduce a type that encapsulates a page-frame-number plus flags. These flags contain the historical "page_link" encoding for a scatterlist entry, but can also denote "device memory". Where "device memory" is a set of pfns that are not part of the kernel's linear mapping by default, but are accessed via the same memory controller as ram. The motivation for this new type is large capacity persistent memory that needs struct page entries in the 'memmap' to support 3rd party DMA (i.e. O_DIRECT I/O with a persistent memory source/target). However, we also need it in support of maintaining a list of mapped inodes which need to be unmapped at driver teardown or freeze_bdev() time. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave@sr71.net> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/dasd: fix failfast for disconnected devicesStefan Haberland2015-12-301-2/+6
| | | | | | | | | | | | | Enabling failfast should let request fail immediately if either an error occurred or the device gets disconnected. For disconnected devices new requests are not fetches from the block queue and therefore failfast is not triggered. Fix by letting the DASD driver fetch requests for disconnected devices with failfast active. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* block: change ->make_request_fn() and users to return a queue cookieJens Axboe2015-11-072-5/+8
| | | | | | | | | No functional changes in this patch, but it prepares us for returning a more useful cookie related to the IO that was queued up. Signed-off-by: Jens Axboe <axboe@fb.com> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com>
* s390/dasd: fix disconnected device with valid path maskStefan Haberland2015-11-031-1/+6
| | | | | | | | | | | | | | | | | | Path verification is either done via dasd_eckd_read_conf() which is triggered during online processing and resume or via do_path_verification_work() which is triggered after path events. The dasd_eckd_read_conf() version added paths unconditionally and did not check if the path mask was empty. This led to devices having the disconnected stop flag set but a valid path mask. So they where not working although they had paths validated successfully. After a resume this state could even not be solved with additional paths added. Fix by checking for an empty path mask in dasd_eckd_read_conf() and clearing the device stop bits for a newly added channel path. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix invalid PAV assignment after suspend/resumeStefan Haberland2015-11-031-4/+16
| | | | | | | | | | | | | | | For a valid PAV assignment the DASD driver needs to notice possibly changed configuration data. Thus the failing of read configuration data should also fail the device restore to prevent invalid PAV assignment. The failed device may get restored after additional paths get available later on. If the restore fails after the device was added to the lcu alias handling it needs to be removed from the alias handling before exiting the restore function. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix double free in dasd_eckd_read_confStefan Haberland2015-11-031-12/+25
| | | | | | | | | | | | | | | The configuration data is stored per path and also the first valid configuration data per device. When dasd_eckd_read_conf is called again after a path got lost the device configuration data is cleared but possibly not the per path configuration data. This might lead to a double free when the lost path gets operational again. Fix by clearing all per path configuration data when the first valid configuration data is received and stored. Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: fix list_del corruption after lcu changesStefan Haberland2015-10-151-1/+4
| | | | | | | | | | | | | | | | | | | | A summary unit check occurs when the lcu updates the PAV configuration e.g. base PAV assignment or PAV mode at all. This requires the reset of the drivers internal pavgroups. Therefore the alias devices are flushed and moved via a temporary list to the active_devices list where they are not associated with a pavgroup. In conjunction with updates to the base device the pavgroup may be removed since both base_list and alias_list are empty. Unfortunately during alias flush and move to the active_device list from alias_list the pavgroup pointer is not deleted in the device private structure. This leads to a list del_corruption if another lcu_update tries to move the device in the non existent pavgroup. Fix by removing the pavgroup pointer after the alias device was moved to the active_devices list. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/diag: add a statistic for diagnose callsMartin Schwidefsky2015-10-141-0/+2
| | | | | | | Introduce /sys/debug/kernel/diag_stat with a statistic how many diagnose calls have been done by each CPU in the system. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/cio: introduce pathmask_to_posSebastian Ott2015-10-141-7/+4
| | | | | | | | | | We often need to correlate an 8 bit path mask with the position in a channel path array. Introduce and use pathmask_to_pos for that task. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/dasd: mark DASD devices as non rotationalChristian Borntraeger2015-10-141-0/+1
| | | | | | | | | | | | | | | | | | We were able to reduce the CPU overhead of big paging scenarios when announcing our paging disks as non-rotational. Almost all dasd devices are implemented in storage servers with cache, raid, striping and lots of magic. There is no point in optimizing the disk schedulers and swap code for a single platter moving arm rotational disks. Given the complexity of the setup and the fact that this change is mostly to disable the additional overhead in swap code, lets keep the other functionality unchanged and do not disable the this device as entropy source - unlike other non-rotational devices. Suggested-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge tag 'libnvdimm-for-4.3' of ↵Linus Torvalds2015-09-081-4/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This update has successfully completed a 0day-kbuild run and has appeared in a linux-next release. The changes outside of the typical drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and the introduction of ZONE_DEVICE + devm_memremap_pages(). Summary: - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic mechanism for adding device-driver-discovered memory regions to the kernel's direct map. This facility is used by the pmem driver to enable pfn_to_page() operations on the page frames returned by DAX ('direct_access' in 'struct block_device_operations'). For now, the 'memmap' allocation for these "device" pages comes from "System RAM". Support for allocating the memmap from device memory will arrive in a later kernel. - Introduce memremap() to replace usages of ioremap_cache() and ioremap_wt(). memremap() drops the __iomem annotation for these mappings to memory that do not have i/o side effects. The replacement of ioremap_cache() with memremap() is limited to the pmem driver to ease merging the api change in v4.3. Completion of the conversion is targeted for v4.4. - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem driver, update the VFS DAX implementation and PMEM api to provide persistence guarantees for kernel operations on a DAX mapping. - Convert the ACPI NFIT 'BLK' driver to map the block apertures as cacheable to improve performance. - Miscellaneous updates and fixes to libnvdimm including support for issuing "address range scrub" commands, clarifying the optimal 'sector size' of pmem devices, a clarification of the usage of the ACPI '_STA' (status) property for DIMM devices, and other minor fixes" * tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits) libnvdimm, pmem: direct map legacy pmem by default libnvdimm, pmem: 'struct page' for pmem libnvdimm, pfn: 'struct page' provider infrastructure x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB add devm_memremap_pages mm: ZONE_DEVICE for "device memory" mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h dax: drop size parameter to ->direct_access() nd_blk: change aperture mapping from WC to WB nvdimm: change to use generic kvfree() pmem, dax: have direct_access use __pmem annotation dax: update I/O path to do proper PMEM flushing pmem: add copy_from_iter_pmem() and clear_pmem() pmem, x86: clean up conditional pmem includes pmem: remove layer when calling arch_has_wmb_pmem() pmem, x86: move x86 PMEM API to new pmem.h header libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option pmem: switch to devm_ allocations devres: add devm_memremap libnvdimm, btt: write and validate parent_uuid ...
| * dax: drop size parameter to ->direct_access()Dan Williams2015-08-281-2/+2
| | | | | | | | | | | | | | | | | | None of the implementations currently use it. The common bdev_direct_access() entry point handles all the size checks before calling ->direct_access(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| * pmem, dax: have direct_access use __pmem annotationRoss Zwisler2015-08-201-4/+6
| | | | | | | | | | | | | | | | | | | | Update the annotation for the kaddr pointer returned by direct_access() so that it is a __pmem pointer. This is consistent with the PMEM driver and with how this direct_access() pointer is used in the DAX code. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds2015-09-022-3/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
| * | block: make generic_make_request handle arbitrarily sized biosKent Overstreet2015-08-132-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach becomes unwieldy and eventually breaks down with stacked devices and devices with dynamic limits, and it adds a lot of complexity. If the block layer could split bios as needed, we could eliminate a lot of complexity elsewhere - particularly in stacked drivers. Code that creates bios can then create whatever size bios are convenient, and more importantly stacked drivers don't have to deal with both their own bio size limitations and the limitations of the (potentially multiple) devices underneath them. In the future this will let us delete merge_bvec_fn and a bunch of other code. We do this by adding calls to blk_queue_split() to the various make_request functions that need it - a few can already handle arbitrary size bios. Note that we add the call _after_ any call to blk_queue_bounce(); this means that blk_queue_split() and blk_recalc_rq_segments() don't need to be concerned with bouncing affecting segment merging. Some make_request_fn() callbacks were simple enough to audit and verify they don't need blk_queue_split() calls. The skipped ones are: * nfhd_make_request (arch/m68k/emu/nfblock.c) * axon_ram_make_request (arch/powerpc/sysdev/axonram.c) * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c) * brd_make_request (ramdisk - drivers/block/brd.c) * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c) * loop_make_request * null_queue_bio * bcache's make_request fns Some others are almost certainly safe to remove now, but will be left for future patches. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ming Lei <ming.lei@canonical.com> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Geoff Levand <geoff@infradead.org> Cc: Jim Paris <jim@jtan.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: skip more mq-based drivers, resolve merge conflicts, etc.] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | block: add a bi_error field to struct bioChristoph Hellwig2015-07-292-3/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | s390/dcssblk: correct out of bounds array indexesMartin Schwidefsky2015-08-191-7/+7
| | | | | | | | | | | | | | | | | | | | Fix a couple of warnings like this: [linux-4.2-rc7/drivers/s390/block/dcssblk.c:553]: (style) Array index 'j' is used before limits check. Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>