From patchwork Sun Jan 9 01:28:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 12707670 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 D2F51C433EF for ; Sun, 9 Jan 2022 01:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235073AbiAIB3I (ORCPT ); Sat, 8 Jan 2022 20:29:08 -0500 Received: from smtp.infotech.no ([82.134.31.41]:37828 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233631AbiAIB3G (ORCPT ); Sat, 8 Jan 2022 20:29:06 -0500 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 522B12041C0; Sun, 9 Jan 2022 02:29:05 +0100 (CET) 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 tJSwJW9ZS81u; Sun, 9 Jan 2022 02:29:05 +0100 (CET) Received: from xtwo70.bingwo.ca (unknown [10.16.20.11]) by smtp.infotech.no (Postfix) with ESMTPA id 01B0D20413E; Sun, 9 Jan 2022 02:29:03 +0100 (CET) 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 v2 6/9] scsi_debug: add no_rwlock parameter Date: Sat, 8 Jan 2022 20:28:50 -0500 Message-Id: <20220109012853.301953-7-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220109012853.301953-1-dgilbert@interlog.com> References: <20220109012853.301953-1-dgilbert@interlog.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org By default, this driver places a read lock around all user data fetches and a write lock around all user data modifying operations (e.g. WRITE commands). These locks have "per store" granularity. Other drivers that have a similar function (e.g. null_blk) do not take this data integrity step and run significantly faster in some tests. In the common case of a (simulated) device to device copy (e.g. what dd and its variants do) there should be no need for locks around data accesses. So add the driver and sysfs parameter no_rwlock which is boolean and when set does what its name suggests. The default is false for backward comaptibility. Signed-off-by: Douglas Gilbert --- drivers/scsi/scsi_debug.c | 152 +++++++++++++++++++++++++------------- 1 file changed, 102 insertions(+), 50 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 85dd110c2b65..de9059d06cd5 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -787,6 +787,7 @@ static bool sdebug_clustering; static bool sdebug_host_lock = DEF_HOST_LOCK; static bool sdebug_strict = DEF_STRICT; static bool sdebug_any_injecting_opt; +static bool sdebug_no_rwlock; static bool sdebug_verbose; static bool have_dif_prot; static bool write_since_sync; @@ -3130,6 +3131,50 @@ static int prot_verify_read(struct scsi_cmnd *scp, sector_t start_sec, return ret; } +static inline void +sdeb_read_lock(struct sdeb_store_info *sip) +{ + if (sdebug_no_rwlock) + return; + if (sip) + read_lock(&sip->macc_lck); + else + read_lock(&sdeb_fake_rw_lck); +} + +static inline void +sdeb_read_unlock(struct sdeb_store_info *sip) +{ + if (sdebug_no_rwlock) + return; + if (sip) + read_unlock(&sip->macc_lck); + else + read_unlock(&sdeb_fake_rw_lck); +} + +static inline void +sdeb_write_lock(struct sdeb_store_info *sip) +{ + if (sdebug_no_rwlock) + return; + if (sip) + write_lock(&sip->macc_lck); + else + write_lock(&sdeb_fake_rw_lck); +} + +static inline void +sdeb_write_unlock(struct sdeb_store_info *sip) +{ + if (sdebug_no_rwlock) + return; + if (sip) + write_unlock(&sip->macc_lck); + else + write_unlock(&sdeb_fake_rw_lck); +} + static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) { bool check_prot; @@ -3138,7 +3183,6 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) int ret; u64 lba; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; u8 *cmd = scp->cmnd; switch (cmd[0]) { @@ -3217,29 +3261,29 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) return check_condition_result; } - read_lock(macc_lckp); + sdeb_read_lock(sip); /* DIX + T10 DIF */ if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) { switch (prot_verify_read(scp, lba, num, ei_lba)) { case 1: /* Guard tag error */ if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */ - read_unlock(macc_lckp); + sdeb_read_unlock(sip); mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1); return check_condition_result; } else if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) { - read_unlock(macc_lckp); + sdeb_read_unlock(sip); mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1); return illegal_condition_result; } break; case 3: /* Reference tag error */ if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */ - read_unlock(macc_lckp); + sdeb_read_unlock(sip); mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3); return check_condition_result; } else if (scp->prot_flags & SCSI_PROT_REF_CHECK) { - read_unlock(macc_lckp); + sdeb_read_unlock(sip); mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3); return illegal_condition_result; } @@ -3248,7 +3292,7 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) } ret = do_device_access(sip, scp, 0, lba, num, false); - read_unlock(macc_lckp); + sdeb_read_unlock(sip); if (unlikely(ret == -1)) return DID_ERROR << 16; @@ -3436,7 +3480,6 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) int ret; u64 lba; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; u8 *cmd = scp->cmnd; switch (cmd[0]) { @@ -3491,10 +3534,10 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) "to DIF device\n"); } - write_lock(macc_lckp); + sdeb_write_lock(sip); ret = check_device_access_params(scp, lba, num, true); if (ret) { - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return ret; } @@ -3503,22 +3546,22 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) switch (prot_verify_write(scp, lba, num, ei_lba)) { case 1: /* Guard tag error */ if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) { - write_unlock(macc_lckp); + sdeb_write_unlock(sip); mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1); return illegal_condition_result; } else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */ - write_unlock(macc_lckp); + sdeb_write_unlock(sip); mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1); return check_condition_result; } break; case 3: /* Reference tag error */ if (scp->prot_flags & SCSI_PROT_REF_CHECK) { - write_unlock(macc_lckp); + sdeb_write_unlock(sip); mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3); return illegal_condition_result; } else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */ - write_unlock(macc_lckp); + sdeb_write_unlock(sip); mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3); return check_condition_result; } @@ -3532,7 +3575,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) /* If ZBC zone then bump its write pointer */ if (sdebug_dev_is_zoned(devip)) zbc_inc_wp(devip, lba, num); - write_unlock(macc_lckp); + sdeb_write_unlock(sip); if (unlikely(-1 == ret)) return DID_ERROR << 16; else if (unlikely(sdebug_verbose && @@ -3572,7 +3615,6 @@ static int resp_write_scat(struct scsi_cmnd *scp, u8 *lrdp = NULL; u8 *up; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; u8 wrprotect; u16 lbdof, num_lrd, k; u32 num, num_by, bt_len, lbdof_blen, sg_off, cum_lb; @@ -3640,7 +3682,7 @@ static int resp_write_scat(struct scsi_cmnd *scp, goto err_out; } - write_lock(macc_lckp); + sdeb_write_lock(sip); sg_off = lbdof_blen; /* Spec says Buffer xfer Length field in number of LBs in dout */ cum_lb = 0; @@ -3722,7 +3764,7 @@ static int resp_write_scat(struct scsi_cmnd *scp, } ret = 0; err_out_unlock: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); err_out: kfree(lrdp); return ret; @@ -3739,15 +3781,14 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, int ret; struct sdeb_store_info *sip = devip2sip((struct sdebug_dev_info *) scp->device->hostdata, true); - rwlock_t *macc_lckp = &sip->macc_lck; u8 *fs1p; u8 *fsp; - write_lock(macc_lckp); + sdeb_write_lock(sip); ret = check_device_access_params(scp, lba, num, true); if (ret) { - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return ret; } @@ -3767,7 +3808,7 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, ret = fetch_to_dev_buffer(scp, fs1p, lb_size); if (-1 == ret) { - write_unlock(&sip->macc_lck); + sdeb_write_unlock(sip); return DID_ERROR << 16; } else if (sdebug_verbose && !ndob && (ret < lb_size)) sdev_printk(KERN_INFO, scp->device, @@ -3786,7 +3827,7 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num, if (sdebug_dev_is_zoned(devip)) zbc_inc_wp(devip, lba, num); out: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return 0; } @@ -3899,7 +3940,6 @@ static int resp_comp_write(struct scsi_cmnd *scp, u8 *cmd = scp->cmnd; u8 *arr; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; u64 lba; u32 dnum; u32 lb_size = sdebug_sector_size; @@ -3932,7 +3972,7 @@ static int resp_comp_write(struct scsi_cmnd *scp, return check_condition_result; } - write_lock(macc_lckp); + sdeb_write_lock(sip); ret = do_dout_fetch(scp, dnum, arr); if (ret == -1) { @@ -3950,7 +3990,7 @@ static int resp_comp_write(struct scsi_cmnd *scp, if (scsi_debug_lbp()) map_region(sip, lba, num); cleanup: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); kfree(arr); return retval; } @@ -3966,7 +4006,6 @@ static int resp_unmap(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) unsigned char *buf; struct unmap_block_desc *desc; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; unsigned int i, payload_len, descriptors; int ret; @@ -3995,7 +4034,7 @@ static int resp_unmap(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) desc = (void *)&buf[8]; - write_lock(macc_lckp); + sdeb_write_lock(sip); for (i = 0 ; i < descriptors ; i++) { unsigned long long lba = get_unaligned_be64(&desc[i].lba); @@ -4011,7 +4050,7 @@ static int resp_unmap(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) ret = 0; out: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); kfree(buf); return ret; @@ -4103,7 +4142,6 @@ static int resp_pre_fetch(struct scsi_cmnd *scp, u32 nblks; u8 *cmd = scp->cmnd; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; u8 *fsp = sip->storep; if (cmd[0] == PRE_FETCH) { /* 10 byte cdb */ @@ -4125,12 +4163,12 @@ static int resp_pre_fetch(struct scsi_cmnd *scp, rest = block + nblks - sdebug_store_sectors; /* Try to bring the PRE-FETCH range into CPU's cache */ - read_lock(macc_lckp); + sdeb_read_lock(sip); prefetch_range(fsp + (sdebug_sector_size * block), (nblks - rest) * sdebug_sector_size); if (rest) prefetch_range(fsp, rest * sdebug_sector_size); - read_unlock(macc_lckp); + sdeb_read_unlock(sip); fini: if (cmd[1] & 0x2) res = SDEG_RES_IMMED_MASK; @@ -4251,7 +4289,6 @@ static int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) u8 *arr; u8 *cmd = scp->cmnd; struct sdeb_store_info *sip = devip2sip(devip, true); - rwlock_t *macc_lckp = &sip->macc_lck; bytchk = (cmd[1] >> 1) & 0x3; if (bytchk == 0) { @@ -4290,7 +4327,7 @@ static int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) return check_condition_result; } /* Not changing store, so only need read access */ - read_lock(macc_lckp); + sdeb_read_lock(sip); ret = do_dout_fetch(scp, a_num, arr); if (ret == -1) { @@ -4312,7 +4349,7 @@ static int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) goto cleanup; } cleanup: - read_unlock(macc_lckp); + sdeb_read_unlock(sip); kfree(arr); return ret; } @@ -4332,7 +4369,6 @@ static int resp_report_zones(struct scsi_cmnd *scp, u8 *cmd = scp->cmnd; struct sdeb_zone_state *zsp; struct sdeb_store_info *sip = devip2sip(devip, false); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; if (!sdebug_dev_is_zoned(devip)) { mk_sense_invalid_opcode(scp); @@ -4361,7 +4397,7 @@ static int resp_report_zones(struct scsi_cmnd *scp, return check_condition_result; } - read_lock(macc_lckp); + sdeb_read_lock(sip); desc = arr + 64; for (i = 0; i < max_zones; i++) { @@ -4449,7 +4485,7 @@ static int resp_report_zones(struct scsi_cmnd *scp, ret = fill_from_dev_buffer(scp, arr, min_t(u32, alloc_len, rep_len)); fini: - read_unlock(macc_lckp); + sdeb_read_unlock(sip); kfree(arr); return ret; } @@ -4475,14 +4511,13 @@ static int resp_open_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) struct sdeb_zone_state *zsp; bool all = cmd[14] & 0x01; struct sdeb_store_info *sip = devip2sip(devip, false); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; if (!sdebug_dev_is_zoned(devip)) { mk_sense_invalid_opcode(scp); return check_condition_result; } - write_lock(macc_lckp); + sdeb_write_lock(sip); if (all) { /* Check if all closed zones can be open */ @@ -4531,7 +4566,7 @@ static int resp_open_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) zbc_open_zone(devip, zsp, true); fini: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return res; } @@ -4552,14 +4587,13 @@ static int resp_close_zone(struct scsi_cmnd *scp, struct sdeb_zone_state *zsp; bool all = cmd[14] & 0x01; struct sdeb_store_info *sip = devip2sip(devip, false); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; if (!sdebug_dev_is_zoned(devip)) { mk_sense_invalid_opcode(scp); return check_condition_result; } - write_lock(macc_lckp); + sdeb_write_lock(sip); if (all) { zbc_close_all(devip); @@ -4588,7 +4622,7 @@ static int resp_close_zone(struct scsi_cmnd *scp, zbc_close_zone(devip, zsp); fini: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return res; } @@ -4625,14 +4659,13 @@ static int resp_finish_zone(struct scsi_cmnd *scp, u8 *cmd = scp->cmnd; bool all = cmd[14] & 0x01; struct sdeb_store_info *sip = devip2sip(devip, false); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; if (!sdebug_dev_is_zoned(devip)) { mk_sense_invalid_opcode(scp); return check_condition_result; } - write_lock(macc_lckp); + sdeb_write_lock(sip); if (all) { zbc_finish_all(devip); @@ -4661,7 +4694,7 @@ static int resp_finish_zone(struct scsi_cmnd *scp, zbc_finish_zone(devip, zsp, true); fini: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return res; } @@ -4706,14 +4739,13 @@ static int resp_rwp_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) u8 *cmd = scp->cmnd; bool all = cmd[14] & 0x01; struct sdeb_store_info *sip = devip2sip(devip, false); - rwlock_t *macc_lckp = sip ? &sip->macc_lck : &sdeb_fake_rw_lck; if (!sdebug_dev_is_zoned(devip)) { mk_sense_invalid_opcode(scp); return check_condition_result; } - write_lock(macc_lckp); + sdeb_write_lock(sip); if (all) { zbc_rwp_all(devip); @@ -4741,7 +4773,7 @@ static int resp_rwp_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) zbc_rwp_zone(devip, zsp); fini: - write_unlock(macc_lckp); + sdeb_write_unlock(sip); return res; } @@ -5740,6 +5772,7 @@ module_param_named(medium_error_start, sdebug_medium_error_start, int, S_IRUGO | S_IWUSR); module_param_named(ndelay, sdebug_ndelay, int, S_IRUGO | S_IWUSR); module_param_named(no_lun_0, sdebug_no_lun_0, int, S_IRUGO | S_IWUSR); +module_param_named(no_rwlock, sdebug_no_rwlock, bool, S_IRUGO | S_IWUSR); module_param_named(no_uld, sdebug_no_uld, int, S_IRUGO); module_param_named(num_parts, sdebug_num_parts, int, S_IRUGO); module_param_named(num_tgts, sdebug_num_tgts, int, S_IRUGO | S_IWUSR); @@ -5812,6 +5845,7 @@ MODULE_PARM_DESC(medium_error_count, "count of sectors to return follow on MEDIU MODULE_PARM_DESC(medium_error_start, "starting sector number to return MEDIUM error"); MODULE_PARM_DESC(ndelay, "response delay in nanoseconds (def=0 -> ignore)"); MODULE_PARM_DESC(no_lun_0, "no LU number 0 (def=0 -> have lun 0)"); +MODULE_PARM_DESC(no_rwlock, "don't protect user data reads+writes (def=0)"); MODULE_PARM_DESC(no_uld, "stop ULD (e.g. sd driver) attaching (def=0))"); MODULE_PARM_DESC(num_parts, "number of partitions(def=0)"); MODULE_PARM_DESC(num_tgts, "number of targets per host to simulate(def=1)"); @@ -6374,6 +6408,23 @@ static ssize_t host_max_queue_show(struct device_driver *ddp, char *buf) return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_host_max_queue); } +static ssize_t no_rwlock_show(struct device_driver *ddp, char *buf) +{ + return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_rwlock); +} + +static ssize_t no_rwlock_store(struct device_driver *ddp, const char *buf, size_t count) +{ + bool v; + + if (kstrtobool(buf, &v)) + return -EINVAL; + + sdebug_no_rwlock = v; + return count; +} +static DRIVER_ATTR_RW(no_rwlock); + /* * Since this is used for .can_queue, and we get the hc_idx tag from the bitmap * in range [0, sdebug_host_max_queue), we can't change it. @@ -6739,6 +6790,7 @@ static struct attribute *sdebug_drv_attrs[] = { &driver_attr_lun_format.attr, &driver_attr_max_luns.attr, &driver_attr_max_queue.attr, + &driver_attr_no_rwlock.attr, &driver_attr_no_uld.attr, &driver_attr_scsi_level.attr, &driver_attr_virtual_gb.attr,