From 09e2b0b14690fb13ccfc04af49f156df3e25b152 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Mon, 9 Nov 2015 13:24:28 +0100 Subject: scsi: rescan VPD attributes The VPD page information might change, so we need to be able to update it. This patch implements a VPD page rescan whenever the 'rescan' sysfs attribute is triggered. Signed-off-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Shane Seymour Signed-off-by: Martin K. Petersen diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index d07fb65..b1bf42b 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -782,7 +782,7 @@ void scsi_attach_vpd(struct scsi_device *sdev) int vpd_len = SCSI_VPD_PG_LEN; int pg80_supported = 0; int pg83_supported = 0; - unsigned char *vpd_buf; + unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL; if (sdev->skip_vpd_pages) return; @@ -828,8 +828,16 @@ retry_pg80: kfree(vpd_buf); goto retry_pg80; } + mutex_lock(&sdev->inquiry_mutex); + orig_vpd_buf = sdev->vpd_pg80; sdev->vpd_pg80_len = result; - sdev->vpd_pg80 = vpd_buf; + rcu_assign_pointer(sdev->vpd_pg80, vpd_buf); + mutex_unlock(&sdev->inquiry_mutex); + synchronize_rcu(); + if (orig_vpd_buf) { + kfree(orig_vpd_buf); + orig_vpd_buf = NULL; + } vpd_len = SCSI_VPD_PG_LEN; } @@ -849,8 +857,14 @@ retry_pg83: kfree(vpd_buf); goto retry_pg83; } + mutex_lock(&sdev->inquiry_mutex); + orig_vpd_buf = sdev->vpd_pg83; sdev->vpd_pg83_len = result; - sdev->vpd_pg83 = vpd_buf; + rcu_assign_pointer(sdev->vpd_pg83, vpd_buf); + mutex_unlock(&sdev->inquiry_mutex); + synchronize_rcu(); + if (orig_vpd_buf) + kfree(orig_vpd_buf); } } diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 8324539..a1c195d 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -236,6 +236,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, INIT_LIST_HEAD(&sdev->starved_entry); INIT_LIST_HEAD(&sdev->event_list); spin_lock_init(&sdev->list_lock); + mutex_init(&sdev->inquiry_mutex); INIT_WORK(&sdev->event_work, scsi_evt_thread); INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); @@ -1516,6 +1517,9 @@ EXPORT_SYMBOL(scsi_add_device); void scsi_rescan_device(struct device *dev) { device_lock(dev); + + scsi_attach_vpd(to_scsi_device(dev)); + if (dev->driver && try_module_get(dev->driver->owner)) { struct scsi_driver *drv = to_scsi_driver(dev->driver); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 8d23122..158f1b5 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -760,11 +760,15 @@ show_vpd_##_page(struct file *filp, struct kobject *kobj, \ { \ struct device *dev = container_of(kobj, struct device, kobj); \ struct scsi_device *sdev = to_scsi_device(dev); \ + int ret; \ if (!sdev->vpd_##_page) \ return -EINVAL; \ - return memory_read_from_buffer(buf, count, &off, \ - sdev->vpd_##_page, \ + rcu_read_lock(); \ + ret = memory_read_from_buffer(buf, count, &off, \ + rcu_dereference(sdev->vpd_##_page), \ sdev->vpd_##_page##_len); \ + rcu_read_unlock(); \ + return ret; \ } \ static struct bin_attribute dev_attr_vpd_##_page = { \ .attr = {.name = __stringify(vpd_##_page), .mode = S_IRUGO }, \ diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c index dcb0d76..e234da7 100644 --- a/drivers/scsi/ses.c +++ b/drivers/scsi/ses.c @@ -554,17 +554,22 @@ static void ses_match_to_enclosure(struct enclosure_device *edev, struct scsi_device *sdev) { unsigned char *desc; + unsigned char __rcu *vpd_pg83; struct efd efd = { .addr = 0, }; ses_enclosure_data_process(edev, to_scsi_device(edev->edev.parent), 0); - if (!sdev->vpd_pg83_len) + rcu_read_lock(); + vpd_pg83 = rcu_dereference(sdev->vpd_pg83); + if (!vpd_pg83) { + rcu_read_unlock(); return; + } - desc = sdev->vpd_pg83 + 4; - while (desc < sdev->vpd_pg83 + sdev->vpd_pg83_len) { + desc = vpd_pg83 + 4; + while (desc < vpd_pg83 + sdev->vpd_pg83_len) { enum scsi_protocol proto = desc[0] >> 4; u8 code_set = desc[0] & 0x0f; u8 piv = desc[1] & 0x80; @@ -578,6 +583,7 @@ static void ses_match_to_enclosure(struct enclosure_device *edev, desc += len + 4; } + rcu_read_unlock(); if (efd.addr) { efd.dev = &sdev->sdev_gendev; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index fe89d7c..bde4077 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -109,6 +109,7 @@ struct scsi_device { char type; char scsi_level; char inq_periph_qual; /* PQ from INQUIRY data */ + struct mutex inquiry_mutex; unsigned char inquiry_len; /* valid bytes in 'inquiry' */ unsigned char * inquiry; /* INQUIRY response data */ const char * vendor; /* [back_compat] point into 'inquiry' ... */ @@ -117,9 +118,9 @@ struct scsi_device { #define SCSI_VPD_PG_LEN 255 int vpd_pg83_len; - unsigned char *vpd_pg83; + unsigned char __rcu *vpd_pg83; int vpd_pg80_len; - unsigned char *vpd_pg80; + unsigned char __rcu *vpd_pg80; unsigned char current_tag; /* current tag */ struct scsi_target *sdev_target; /* used only for single_lun */ -- cgit v0.10.2