From patchwork Fri Aug 21 15:41:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 257897 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F258BC433DF for ; Fri, 21 Aug 2020 15:42:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D14332063A for ; Fri, 21 Aug 2020 15:42:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728219AbgHUPmd (ORCPT ); Fri, 21 Aug 2020 11:42:33 -0400 Received: from smtp.infotech.no ([82.134.31.41]:48297 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727849AbgHUPmP (ORCPT ); Fri, 21 Aug 2020 11:42:15 -0400 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 53949204259; Fri, 21 Aug 2020 17:42:10 +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 fM8-XfoiIb8T; Fri, 21 Aug 2020 17:42:07 +0200 (CEST) Received: from xtwo70.bingwo.ca (host-45-78-251-166.dyn.295.ca [45.78.251.166]) by smtp.infotech.no (Postfix) with ESMTPA id EAAFB20415B; Fri, 21 Aug 2020 17:42:06 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de, john.garry@huawei.com Subject: [PATCH v6 01/10] scsi: convert target lookup to xarray Date: Fri, 21 Aug 2020 11:41:55 -0400 Message-Id: <20200821154204.9298-2-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200821154204.9298-1-dgilbert@interlog.com> References: <20200821154204.9298-1-dgilbert@interlog.com> MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Hannes Reinecke Use an xarray instead of lists for holding the scsi targets. I've also shortened the 'channel' and 'id' values to 16 bit as none of the drivers requires a full 32bit range for either of them, and by shortening them we can use them as the index into the xarray for storing the scsi_target pointer. Signed-off-by: Hannes Reinecke Signed-off-by: Douglas Gilbert --- drivers/scsi/hosts.c | 4 +++- drivers/scsi/scsi.c | 32 +++++++++++++++---------- drivers/scsi/scsi_scan.c | 49 ++++++++++++++++---------------------- drivers/scsi/scsi_sysfs.c | 16 +++++++++---- include/scsi/scsi_device.h | 15 ++++++++---- include/scsi/scsi_host.h | 2 +- 6 files changed, 65 insertions(+), 53 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 37d1c5565d90..bcf132320e8f 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -189,6 +189,8 @@ void scsi_remove_host(struct Scsi_Host *shost) transport_unregister_device(&shost->shost_gendev); device_unregister(&shost->shost_dev); device_del(&shost->shost_gendev); + WARN_ON(!xa_empty(&shost->__targets)); + xa_destroy(&shost->__targets); } EXPORT_SYMBOL(scsi_remove_host); @@ -385,7 +387,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) spin_lock_init(shost->host_lock); shost->shost_state = SHOST_CREATED; INIT_LIST_HEAD(&shost->__devices); - INIT_LIST_HEAD(&shost->__targets); + xa_init_flags(&shost->__targets, XA_FLAGS_LOCK_IRQ); INIT_LIST_HEAD(&shost->eh_cmd_q); INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 24619c3bebd5..2cb31b41d8f8 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -575,6 +575,19 @@ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, } EXPORT_SYMBOL(__scsi_iterate_devices); +/** + * __scsi_target_lookup - find a target based on channel and target id + * @shost: SCSI host pointer + * @channel: channel number of the target + * @id: ID of the target + * + */ +static struct scsi_target *__scsi_target_lookup(struct Scsi_Host *shost, + u16 channel, u16 id) +{ + return xa_load(&shost->__targets, (channel << 16) | id); +} + /** * starget_for_each_device - helper to walk all devices of a target * @starget: target whose devices we want to iterate over. @@ -701,19 +714,14 @@ EXPORT_SYMBOL(scsi_device_lookup_by_target); * really want to use scsi_device_lookup instead. **/ struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, - uint channel, uint id, u64 lun) + u16 channel, u16 id, u64 lun) { - struct scsi_device *sdev; + struct scsi_target *starget; - list_for_each_entry(sdev, &shost->__devices, siblings) { - if (sdev->sdev_state == SDEV_DEL) - continue; - if (sdev->channel == channel && sdev->id == id && - sdev->lun ==lun) - return sdev; - } - - return NULL; + starget = __scsi_target_lookup(shost, channel, id); + if (!starget) + return NULL; + return __scsi_device_lookup_by_target(starget, lun); } EXPORT_SYMBOL(__scsi_device_lookup); @@ -729,7 +737,7 @@ EXPORT_SYMBOL(__scsi_device_lookup); * needs to be released with scsi_device_put once you're done with it. **/ struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, - uint channel, uint id, u64 lun) + u16 channel, u16 id, u64 lun) { struct scsi_device *sdev; unsigned long flags; diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index f2437a7570ce..9fc35b6cbc30 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -309,6 +309,7 @@ static void scsi_target_destroy(struct scsi_target *starget) struct device *dev = &starget->dev; struct Scsi_Host *shost = dev_to_shost(dev->parent); unsigned long flags; + unsigned long tid = scsi_target_index(starget); BUG_ON(starget->state == STARGET_DEL); starget->state = STARGET_DEL; @@ -316,7 +317,7 @@ static void scsi_target_destroy(struct scsi_target *starget) spin_lock_irqsave(shost->host_lock, flags); if (shost->hostt->target_destroy) shost->hostt->target_destroy(starget); - list_del_init(&starget->siblings); + xa_erase(&shost->__targets, tid); spin_unlock_irqrestore(shost->host_lock, flags); put_device(dev); } @@ -341,27 +342,6 @@ int scsi_is_target_device(const struct device *dev) } EXPORT_SYMBOL(scsi_is_target_device); -static struct scsi_target *__scsi_find_target(struct device *parent, - int channel, uint id) -{ - struct scsi_target *starget, *found_starget = NULL; - struct Scsi_Host *shost = dev_to_shost(parent); - /* - * Search for an existing target for this sdev. - */ - list_for_each_entry(starget, &shost->__targets, siblings) { - if (starget->id == id && - starget->channel == channel) { - found_starget = starget; - break; - } - } - if (found_starget) - get_device(&found_starget->dev); - - return found_starget; -} - /** * scsi_target_reap_ref_release - remove target from visibility * @kref: the reap_ref in the target being released @@ -417,6 +397,7 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, struct scsi_target *starget; struct scsi_target *found_target; int error, ref_got; + unsigned long tid; starget = kzalloc(size, GFP_KERNEL); if (!starget) { @@ -433,27 +414,37 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, starget->id = id; starget->channel = channel; starget->can_queue = 0; - INIT_LIST_HEAD(&starget->siblings); INIT_LIST_HEAD(&starget->devices); starget->state = STARGET_CREATED; starget->scsi_level = SCSI_2; starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; + tid = scsi_target_index(starget); retry: spin_lock_irqsave(shost->host_lock, flags); - - found_target = __scsi_find_target(parent, channel, id); - if (found_target) + found_target = xa_load(&shost->__targets, tid); + if (found_target) { + get_device(&found_target->dev); goto found; - - list_add_tail(&starget->siblings, &shost->__targets); + } + error = xa_insert(&shost->__targets, tid, starget, GFP_ATOMIC); spin_unlock_irqrestore(shost->host_lock, flags); + if (error) { + dev_printk(KERN_ERR, dev, + "target %u:%u index allocation failed, error %d\n", + channel, id, error); + put_device(dev); + kfree(starget); + return NULL; + } /* allocate and add */ transport_setup_device(dev); if (shost->hostt->target_alloc) { error = shost->hostt->target_alloc(starget); if(error) { - dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); + dev_printk(KERN_ERR, dev, + "target %u:%u allocation failed, error %d\n", + channel, id, error); /* don't want scsi_target_reap to do the final * put because it will be under the host lock */ scsi_target_destroy(starget); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 163dbcb741c1..83bdcb032853 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1511,16 +1511,21 @@ static void __scsi_remove_target(struct scsi_target *starget) void scsi_remove_target(struct device *dev) { struct Scsi_Host *shost = dev_to_shost(dev->parent); - struct scsi_target *starget; + struct scsi_target *starget, *starget_next; + unsigned long tid = 0; unsigned long flags; -restart: spin_lock_irqsave(shost->host_lock, flags); - list_for_each_entry(starget, &shost->__targets, siblings) { + starget = xa_find(&shost->__targets, &tid, UINT_MAX, XA_PRESENT); + while (starget) { + starget_next = xa_find_after(&shost->__targets, &tid, + UINT_MAX, XA_PRESENT); if (starget->state == STARGET_DEL || starget->state == STARGET_REMOVE || - starget->state == STARGET_CREATED_REMOVE) + starget->state == STARGET_CREATED_REMOVE) { + starget = starget_next; continue; + } if (starget->dev.parent == dev || &starget->dev == dev) { kref_get(&starget->reap_ref); if (starget->state == STARGET_CREATED) @@ -1530,8 +1535,9 @@ void scsi_remove_target(struct device *dev) spin_unlock_irqrestore(shost->host_lock, flags); __scsi_remove_target(starget); scsi_target_reap(starget); - goto restart; + spin_lock_irqsave(shost->host_lock, flags); } + starget = starget_next; } spin_unlock_irqrestore(shost->host_lock, flags); } diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index bc5909033d13..867559eca33d 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -121,7 +121,7 @@ struct scsi_device { unsigned long last_queue_ramp_up; /* last queue ramp up time */ - unsigned int id, channel; + u16 id, channel; u64 lun; unsigned int manufacturer; /* Manufacturer of device, for using * vendor-specific cmd's */ @@ -291,8 +291,8 @@ struct scsi_target { struct list_head devices; struct device dev; struct kref reap_ref; /* last put renders target invisible */ - unsigned int channel; - unsigned int id; /* target id ... replace + u16 channel; + u16 id; /* target id ... replace * scsi_device.id eventually */ unsigned int create:1; /* signal that it needs to be added */ unsigned int single_lun:1; /* Indicates we should only @@ -324,6 +324,11 @@ struct scsi_target { /* starget_data must be the last element!!!! */ } __attribute__((aligned(sizeof(unsigned long)))); +static inline u32 scsi_target_index(struct scsi_target *starget) +{ + return (starget->channel << 16) | (starget->id); +} + #define to_scsi_target(d) container_of(d, struct scsi_target, dev) static inline struct scsi_target *scsi_target(struct scsi_device *sdev) { @@ -348,9 +353,9 @@ extern struct scsi_device *scsi_device_from_queue(struct request_queue *q); extern int __must_check scsi_device_get(struct scsi_device *); extern void scsi_device_put(struct scsi_device *); extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *, - uint, uint, u64); + u16, u16, u64); extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *, - uint, uint, u64); + u16, u16, u64); extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *, u64); extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *, diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 46ef8cccc982..d0a765dd995a 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -528,7 +528,7 @@ struct Scsi_Host { * access this list directly from a driver. */ struct list_head __devices; - struct list_head __targets; + struct xarray __targets; struct list_head starved_list;