user/sven/linux.git/include/linux/scatterlist.h, branch v5.4.198

scsi: lib/sg_pool.c: improve APIs for allocating sg pool

2019-06-20T19:21:33Z

sg_alloc_table_chained() currently allows the caller to provide one preallocated SGL and returns if the requested number isn't bigger than size of that SGL. This is used to inline an SGL for an IO request. However, scattergather code only allows that size of the 1st preallocated SGL to be SG_CHUNK_SIZE(128). This means a substantial amount of memory (4KB) is claimed for the SGL for each IO request. If the I/O is small, it would be prudent to allocate a smaller SGL. Introduce an extra parameter to sg_alloc_table_chained() and sg_free_table_chained() for specifying size of the preallocated SGL. Both __sg_free_table() and __sg_alloc_table() assume that each SGL has the same size except for the last one. Change the code to allow both functions to accept a variable size for the 1st preallocated SGL. [mkp: attempted to clarify commit desc] Cc: Christoph Hellwig Cc: Bart Van Assche Cc: Ewan D. Milne Cc: Hannes Reinecke Cc: Sagi Grimberg Cc: Chuck Lever Cc: netdev@vger.kernel.org Cc: linux-nvme@lists.infradead.org Suggested-by: Christoph Hellwig Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

lib/scatterlist: Remove leftover from sg_page_iter comment

2019-05-07T15:47:47Z

Commit d901b2760dc6 ("lib/scatterlist: Provide a DMA page iterator") added the sg DMA iterator but a leftover remained in the sg_page_iter documentation as you cannot get the page dma address (only the page itself), fix it. Signed-off-by: Gal Pressman Reviewed-by: Mukesh Ojha Signed-off-by: Jason Gunthorpe

lib/scatterlist: Provide a DMA page iterator

2019-02-11T22:02:33Z

Commit 2db76d7c3c6d ("lib/scatterlist: sg_page_iter: support sg lists w/o backing pages") introduced the sg_page_iter_dma_address() function without providing a way to use it in the general case. If the sg_dma_len() is not equal to the sg length callers cannot safely use the for_each_sg_page/sg_page_iter_dma_address combination. Resolve this API mistake by providing a DMA specific iterator, for_each_sg_dma_page(), that uses the right length so sg_page_iter_dma_address() works as expected with all sglists. A new iterator type is introduced to provide compile-time safety against wrongly mixing accessors and iterators. Acked-by: Christoph Hellwig (for scatterlist) Acked-by: Thomas Hellstrom Acked-by: Sakari Ailus (ipu3-cio2) Signed-off-by: Jason Gunthorpe

arch: switch the default on ARCH_HAS_SG_CHAIN

2018-12-06T15:04:56Z

These days architectures are mostly out of the business of dealing with struct scatterlist at all, unless they have architecture specific iommu drivers. Replace the ARCH_HAS_SG_CHAIN symbol with a ARCH_NO_SG_CHAIN one only enabled for architectures with horrible legacy iommu drivers like alpha and parisc, and conditionally for arm which wants to keep it disable for legacy platforms. Signed-off-by: Christoph Hellwig Reviewed-by: Palmer Dabbelt

sg: remove ->sg_magic member

2018-06-29T14:48:06Z

This was introduced more than a decade ago when sg chaining was added, but we never really caught anything with it. The scatterlist entry size can be critical, since drivers allocate it, so remove the magic member. Recently it's been triggering allocation stalls and failures in NVMe. Tested-by: Jordan Glover Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block

2018-04-05T21:27:02Z

Pull block layer updates from Jens Axboe: "It's a pretty quiet round this time, which is nice. This contains: - series from Bart, cleaning up the way we set/test/clear atomic queue flags. - series from Bart, fixing races between gendisk and queue registration and removal. - set of bcache fixes and improvements from various folks, by way of Michael Lyle. - set of lightnvm updates from Matias, most of it being the 1.2 to 2.0 transition. - removal of unused DIO flags from Nikolay. - blk-mq/sbitmap memory ordering fixes from Omar. - divide-by-zero fix for BFQ from Paolo. - minor documentation patches from Randy. - timeout fix from Tejun. - Alpha "can't write a char atomically" fix from Mikulas. - set of NVMe fixes by way of Keith. - bsg and bsg-lib improvements from Christoph. - a few sed-opal fixes from Jonas. - cdrom check-disk-change deadlock fix from Maurizio. - various little fixes, comment fixes, etc from various folks" * tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits) blk-mq: Directly schedule q->timeout_work when aborting a request blktrace: fix comment in blktrace_api.h lightnvm: remove function name in strings lightnvm: pblk: remove some unnecessary NULL checks lightnvm: pblk: don't recover unwritten lines lightnvm: pblk: implement 2.0 support lightnvm: pblk: implement get log report chunk lightnvm: pblk: rename ppaf* to addrf* lightnvm: pblk: check for supported version lightnvm: implement get log report chunk helpers lightnvm: make address conversions depend on generic device lightnvm: add support for 2.0 address format lightnvm: normalize geometry nomenclature lightnvm: complete geo structure with maxoc* lightnvm: add shorten OCSSD version in geo lightnvm: add minor version to generic geometry lightnvm: simplify geometry structure lightnvm: pblk: refactor init/exit sequences lightnvm: Avoid validation of default op value lightnvm: centralize permission check for lightnvm ioctl ...

lib/scatterlist: add sg_init_marker() helper

2018-03-30T20:50:15Z

sg_init_marker initializes sg_magic in the sg table and calls sg_mark_end() on the last entry of the table. This can be useful to avoid memset in sg_init_table() when scatterlist is already zeroed out For example: when scatterlist is embedded inside other struct and that container struct is zeroed out Suggested-by: Daniel Borkmann Signed-off-by: Prashant Bhole Acked-by: John Fastabend Signed-off-by: Daniel Borkmann

lib/scatterlist: Add SG_CHAIN and SG_END macros for LSB encodings

2018-02-28T19:23:35Z

This replaces scatterlist->page_link LSB encodings with SG_CHAIN and SG_END definitions without any functional change. Signed-off-by: Anshuman Khandual Signed-off-by: Jens Axboe

lib/scatterlist: Fix chaining support in sgl_alloc_order()

2018-01-19T19:31:03Z

This patch avoids that workloads with large block sizes (megabytes) can trigger the following call stack with the ib_srpt driver (that driver is the only driver that chains scatterlists allocated by sgl_alloc_order()): BUG: Bad page state in process kworker/0:1H pfn:2423a78 page:fffffb03d08e9e00 count:-3 mapcount:0 mapping: (null) index:0x0 flags: 0x57ffffc0000000() raw: 0057ffffc0000000 0000000000000000 0000000000000000 fffffffdffffffff raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000 page dumped because: nonzero _count CPU: 0 PID: 733 Comm: kworker/0:1H Tainted: G I 4.15.0-rc7.bart+ #1 Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015 Workqueue: ib-comp-wq ib_cq_poll_work [ib_core] Call Trace: dump_stack+0x5c/0x83 bad_page+0xf5/0x10f get_page_from_freelist+0xa46/0x11b0 __alloc_pages_nodemask+0x103/0x290 sgl_alloc_order+0x101/0x180 target_alloc_sgl+0x2c/0x40 [target_core_mod] srpt_alloc_rw_ctxs+0x173/0x2d0 [ib_srpt] srpt_handle_new_iu+0x61e/0x7f0 [ib_srpt] __ib_process_cq+0x55/0xa0 [ib_core] ib_cq_poll_work+0x1b/0x60 [ib_core] process_one_work+0x141/0x340 worker_thread+0x47/0x3e0 kthread+0xf5/0x130 ret_from_fork+0x1f/0x30 Fixes: e80a0af4759a ("lib/scatterlist: Introduce sgl_alloc() and sgl_free()") Reported-by: Laurence Oberman Tested-by: Laurence Oberman Signed-off-by: Bart Van Assche Cc: Nicholas A. Bellinger Cc: Laurence Oberman Signed-off-by: Jens Axboe

lib/scatterlist: Introduce sgl_alloc() and sgl_free()

2018-01-06T16:18:00Z

Many kernel drivers contain code that allocates and frees both a scatterlist and the pages that populate that scatterlist. Introduce functions in lib/scatterlist.c that perform these tasks instead of duplicating this functionality in multiple drivers. Only include these functions in the build if CONFIG_SGL_ALLOC=y to avoid that the kernel size increases if this functionality is not used. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe