linux/drivers/block/brd.c, branch v4.3

Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2015-09-08T21:35:59Z

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()

2015-08-27T23:40:58Z

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 Signed-off-by: Dan Williams

pmem, dax: have direct_access use __pmem annotation

2015-08-20T18:07:24Z

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 Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams

block: add a bi_error field to struct bio

2015-07-29T14:55:15Z

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 Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe

block: have drivers use blk_queue_max_discard_sectors()

2015-07-17T14:41:53Z

Some drivers use it now, others just set the limits field manually. But in preparation for splitting this into a hard and soft limit, ensure that they all call the proper function for setting the hw limit for discards. Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe

brd: rename XIP to DAX

2015-02-17T01:56:04Z

Since this is relating to FS_XIP, not KERNEL_XIP, it should be called DAX instead of XIP. Signed-off-by: Matthew Wilcox Cc: Andreas Dilger Cc: Boaz Harrosh Cc: Christoph Hellwig Cc: Dave Chinner Cc: Jan Kara Cc: Jens Axboe Cc: Kirill A. Shutemov Cc: Mathieu Desnoyers Cc: Randy Dunlap Cc: Ross Zwisler Cc: Theodore Ts'o Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

brd: Request from fdisk 4k alignment

2015-01-14T04:59:15Z

Because of the direct_access() API which returns a PFN. partitions better start on 4K boundary, else offset ZERO of a partition will not be aligned and blk_direct_access() will fail the call. By setting blk_queue_physical_block_size(PAGE_SIZE) we can communicate this to fdisk and friends. The call to blk_queue_physical_block_size() is harmless and will not affect the Kernel behavior in any way. It is only for communication to user-mode. before this patch running fdisk on a default size brd of 4M the first sector offered is 34 (BAD), but after this patch it will be 40, ie 8 sectors aligned. Also when entering some random partition sizes the next partition-start sector is offered 8 sectors aligned after this patch. (Please note that with fdisk the user can still enter bad values, only the offered default values will be correct) Note that with bdev-size > 4M fdisk will try to align on a 1M boundary (above first-sector will be 2048), in any case. CC: Martin K. Petersen Signed-off-by: Boaz Harrosh Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

brd: Fix all partitions BUGs

2015-01-14T04:59:03Z

This patch fixes up brd's partitions scheme, now enjoying all worlds. The MAIN fix here is that currently, if one fdisks some partitions, a BAD bug will make all partitions point to the same start-end sector ie: 0 - brd_size And an mkfs of any partition would trash the partition table and the other partition. Another fix is that "mount -U uuid" will not work if show_part was not specified, because of the GENHD_FL_SUPPRESS_PARTITION_INFO flag. We now always load without it and remove the show_part parameter. [We remove Dmitry's new module-param part_show it is now always show] So NOW the logic goes like this: * max_part - Just says how many minors to reserve between ramX devices. In any way, there can be as many partition as requested. If minors between devices ends, then dynamic 259-major ids will be allocated on the fly. The default is now max_part=1, which means all partitions devt(s) will be from the dynamic (259) major-range. (If persistent partition minors is needed use max_part=X) For example with /dev/sdX max_part is hard coded 16. * Creation of new devices on the fly still/always work: mknod /path/devnod b 1 X fdisk -l /path/devnod Will create a new device if [X / max_part] was not already created before. (Just as before) partitions on the dynamically created device will work as well Same logic applies with minors as with the pre-created ones. TODO: dynamic grow of device size. So each device can have it's own size. CC: Dmitry Monakhov Tested-by: Ross Zwisler Signed-off-by: Boaz Harrosh Signed-off-by: Jens Axboe

block: Change direct_access calling convention

2015-01-14T04:58:11Z

In order to support accesses to larger chunks of memory, pass in a 'size' parameter (counted in bytes), and return the amount available at that address. Add a new helper function, bdev_direct_access(), to handle common functionality including partition handling, checking the length requested is positive, checking for the sector being page-aligned, and checking the length of the request does not pass the end of the partition. Signed-off-by: Matthew Wilcox Reviewed-by: Jan Kara Reviewed-by: Boaz Harrosh Signed-off-by: Jens Axboe

brd: add ram disk visibility option

2014-08-22T01:42:01Z

Currenly ram disk is not visiable inside /proc/partitions. This was done for compatibility reasons here: 53978d0a7a27. But some utilities expect disk presents in /proc/partitions. Let's add module's option and let's administrator chose visibility behaviour. By default, old behaviour preserved. Signed-off-by: Dmitry Monakhov Signed-off-by: Jens Axboe