From patchwork Mon Apr 11 02:27:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 12808399 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14F87C433F5 for ; Mon, 11 Apr 2022 02:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239644AbiDKCbD (ORCPT ); Sun, 10 Apr 2022 22:31:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229622AbiDKCbC (ORCPT ); Sun, 10 Apr 2022 22:31:02 -0400 Received: from smtp.infotech.no (smtp.infotech.no [82.134.31.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0342138793 for ; Sun, 10 Apr 2022 19:28:47 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 4BD722041D4; Mon, 11 Apr 2022 04:28:47 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id FydBkdywVFxf; Mon, 11 Apr 2022 04:28:40 +0200 (CEST) Received: from xtwo70.bingwo.ca (host-45-78-195-155.dyn.295.ca [45.78.195.155]) by smtp.infotech.no (Postfix) with ESMTPA id 2BB83204179; Mon, 11 Apr 2022 04:28:38 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de, bvanassche@acm.org Subject: [PATCH v24 00/46] sg: add v4 interface Date: Sun, 10 Apr 2022 22:27:50 -0400 Message-Id: <20220411022836.11871-1-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org This patchset is the first stage of a two stage rewrite of the scsi generic (sg) driver. The main goal of the first stage is to introduce the sg v4 interface that uses 'struct sg_io_v4' as well as keeping and modernizing the sg v3 interface (based on 'struct sg_io_hdr'). The async interface formerly requiring the use of write() and read() system calls now has ioctl(SG_IOSUBMIT) and ioctl(SG_IORECEIVE) replacements. The sg v4 interface is not new, it has been used by the bsg driver since it was introduced to the kernel around 15 years ago. For documentation see either url: https://sg.danny.cz/sg/sg_v40.html https://doug-gilbert.github.io/sg_v40.html This driver has been tested with utilities found at: https://github.com/doug-gilbert/sg3_utils specifically sgh_dd found under the testing directory. The new statistics gathering facility can be tested with either sgstat or 'tapestat -g' using the author's clone of the sysstat package: https://github.com/doug-gilbert/sysstat This patchset is against Martin Petersen's 5.19/scsi-queue branch. Changes since v21 (sent to linux-scsi list on 20211003) - versions 21, 22 and 23 failed under heavy load when the 'POLLED' flag (formerly 'HIPRI') was used. It took several kernel cycles for driver to successfully pass that area of the testing code. Bug fixes in the scsi_debug driver and most likely the block layer issues were the probable culprits - rebase against lk 5.18.0-rc1 - introduce 'struct block_device *dummy_bdev' in struct sg_device to circumvent the block API shut-out of char devices using bio_poll(). bio_poll() was formerly called blk_poll(). The dummy block_device object is only associated with a sg_device the first time a SGV4_FLAG_POLLED flag is set on a pass-through command. So only sg devices that actually use bio_poll() are burdened with carrying a block_device object. The dummy block_device object only holds parameters like the request_queue that were formerly given directly to blk_poll(). The NVMe pass-through will face the same problem if it tries to use bio_poll() Changes since v20 (sent to linux-scsi list on 20210915) - apply changes requested by Damien Le Moal to '[PATCH v21 00/46] sg: add statistics similar to st' patch. Drop comp_stats option; statistics always gathered - fix broken usage of scsi_cmd_allowed() introduced in lk 5.15.0-rc1 Changes since v19 (sent to linux-scsi list on 20210523) - add statistics gathering similar to that found in st driver. The tapestat utility in the sysstat package can be used to display those statistics; similar arrangement for the sg driver. Make changes suggested by Damien Le Moal. - rebase on 5.16/scsi-queue branch [lk 5.15.0-rc1] - gendisk dependency removed - various other Christoph Hellwig cleanups Changes since v18 (sent to linux-scsi list on 20210407) - a request queue's QUEUE_FLAG_POLL flag can be cleared via sysfs, overriding the ability to use blk_poll() even when the associated LLD allows it. Check that flag and, only when it is set and the sg user gives SGV4_FLAG_HIPRI, set REQ_HIPRI on a request. - simplify the functions supporting ioctl(SG_SET_RESERVED_SIZE) - replace blk_rq_append_bio() calls with the simpler blk_rq_bio_prep() calls [see lk: a4fe2d3afe3ce77edeadb567c0d0a8d102c6b159] - rebase on 5.14/scsi-queue branch [lk 5.13.0-rc1] - unchecked_isa_dma removed - BIO_MAX_PAGES renamed to BIO_MAX_VECS Changes since v17 (sent to linux-scsi list on 20210407) - make clearer distinction between user pollable (i.e. async) requests and (user) non-pollable requests (e.g. those injected with ioctl(SG_IO), IOWs sync requests) - fix crash is sg_start_req() when blk_get_request() yields an error (e.g. -EAGAIN when low on resources) - sg_finish_scsi_blk_rq(): remove now_zero variable as suggested by Hannes R. - change deprecation warning url reference from http to https Changes since v16 (sent to linux-scsi list on 20210208) - sg_start_req() fix double free on error path [KASAN] - sg_rq_map_kern() fix uninitialized variable [coverity] - sg_add_sfp() fix use after free [coverity] - sg_remove_sfp_usercontext(): remove pointless NULL check [coverity] - fix misuse of WARN_ONCE in sg_rq_end_io_usercontext() [D. Carpenter] - remove unused error checks: tracking blk_put_request() calls and multiple SG_XA_RQ_FREE calls - hipri: as blk_poll() can return > 0 for requests other than the one that is being checked for, need to re-check that request is ready - rebased on MKP's 5.13/scsi-queue Changes since v15 (sent to linux-scsi list on 20210125) - tweak state machine which sets INFLIGHT state _before_ blk_execute_rq_nowait() is called. Add a bit flag that indicates the logic flow has returned from that call. This guards against blk_poll() being called before the block layer has really launched the request. - fix bug clearing SG_FFD_HIPRI_SEEN bit as atomic_dec_and_test() returns true when the post-decrement value is zero, the opposite of what a C conditional does. Changes since v14 and earlier - see: the v18 patchset sent to linux-scsi on 20210427 Douglas Gilbert (46): sg: move functions around sg: remove typedefs, type+formatting cleanup sg: sg_log and is_enabled sg: rework sg_poll(), minor changes sg: bitops in sg_device sg: make open count an atomic sg: move header to uapi section sg: speed sg_poll and sg_get_num_waiting sg: sg_allow_if_err_recovery and renames sg: improve naming sg: change rwlock to spinlock sg: ioctl handling sg: split sg_read sg: sg_common_write add structure for arguments sg: rework sg_vma_fault sg: rework sg_mmap sg: replace sg_allow_access sg: rework scatter gather handling sg: introduce request state machine sg: sg_find_srp_by_id sg: sg_fill_request_element sg: printk change %p to %pK sg: xarray for fds in device sg: xarray for reqs in fd sg: replace rq array with xarray sg: sense buffer rework sg: add sg v4 interface support sg: rework debug info sg: add 8 byte SCSI LUN to sg_scsi_id sg: expand sg_comm_wr_t sg: add sg_iosubmit_v3 and sg_ioreceive_v3 ioctls sg: add some __must_hold macros sg: move procfs objects to avoid forward decls sg: protect multiple receivers sg: first debugfs support sg: rework mmap support sg: defang allow_dio sg: warn v3 write system call users sg: add mmap_sz tracking sg: remove rcv_done request state sg: track lowest inactive and await indexes sg: remove unit attention check for device changed sg: no_dxfer: move to/from kernel buffers sg: add bio_poll support sg: add statistics similar to st sg: bump version to 4.0.13 drivers/scsi/sg.c | 5552 ++++++++++++++++++++++++++++------------ include/scsi/sg.h | 301 +-- include/uapi/scsi/sg.h | 408 +++ 3 files changed, 4318 insertions(+), 1943 deletions(-) create mode 100644 include/uapi/scsi/sg.h