From patchwork Fri May 29 13:47:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 11578753 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 87FD2739 for ; Fri, 29 May 2020 13:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 739DC207BC for ; Fri, 29 May 2020 13:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726958AbgE2Nrj (ORCPT ); Fri, 29 May 2020 09:47:39 -0400 Received: from mx2.suse.de ([195.135.220.15]:35678 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726827AbgE2Nri (ORCPT ); Fri, 29 May 2020 09:47:38 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id D1220AF72; Fri, 29 May 2020 13:47:36 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: Christoph Hellwig , Doug Gilbert , Daniel Wagner , Johannes Thumshirn , James Bottomley , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH 1/5] scsi: convert target lookup to xarray Date: Fri, 29 May 2020 15:47:26 +0200 Message-Id: <20200529134730.146573-2-hare@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200529134730.146573-1-hare@suse.de> References: <20200529134730.146573-1-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org 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 --- drivers/scsi/hosts.c | 3 ++- drivers/scsi/scsi.c | 32 ++++++++++++++++++------------ drivers/scsi/scsi_scan.c | 49 ++++++++++++++++++++-------------------------- drivers/scsi/scsi_sysfs.c | 9 ++++++--- include/scsi/scsi_device.h | 15 +++++++++----- include/scsi/scsi_host.h | 2 +- 6 files changed, 60 insertions(+), 50 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 7ec91c3a66ca..87537b0745c1 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -189,6 +189,7 @@ void scsi_remove_host(struct Scsi_Host *shost) transport_unregister_device(&shost->shost_gendev); device_unregister(&shost->shost_dev); device_del(&shost->shost_gendev); + xa_destroy(&shost->__targets); } EXPORT_SYMBOL(scsi_remove_host); @@ -383,7 +384,7 @@ 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 56c24a73e0c7..d601424e32b2 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..b72265614a9b 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) { @@ -433,19 +414,29 @@ 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); + if (error) { + dev_printk(KERN_ERR, dev, + "target %u:%u index allocation failed, error %d\n", + channel, id, error); + spin_unlock_irqrestore(shost->host_lock, flags); + put_device(dev); + kfree(starget); + return NULL; + } spin_unlock_irqrestore(shost->host_lock, flags); /* allocate and add */ transport_setup_device(dev); @@ -453,7 +444,9 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, 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..a694b25be5da 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1512,11 +1512,14 @@ void scsi_remove_target(struct device *dev) { struct Scsi_Host *shost = dev_to_shost(dev->parent); struct scsi_target *starget; + unsigned long tid = 0; unsigned long flags; -restart: spin_lock_irqsave(shost->host_lock, flags); - list_for_each_entry(starget, &shost->__targets, siblings) { + for(starget = xa_find(&shost->__targets, &tid, UINT_MAX, XA_PRESENT); + (starget); + starget = xa_find_after(&shost->__targets, &tid, + UINT_MAX, XA_PRESENT)) { if (starget->state == STARGET_DEL || starget->state == STARGET_REMOVE || starget->state == STARGET_CREATED_REMOVE) @@ -1530,7 +1533,7 @@ 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); } } spin_unlock_irqrestore(shost->host_lock, flags); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index c3cba2aaf934..8cb31bbd8a82 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 */ @@ -288,8 +288,8 @@ 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 @@ -321,6 +321,11 @@ 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) { @@ -345,9 +350,9 @@ 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 822e8cda8d9b..b9395676c75b 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -521,7 +521,7 @@ 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;