From: Horst Hummel Date: Sat, 3 Sep 2005 22:57:58 +0000 (-0700) Subject: [PATCH] s390: deadlock in dasd_devmap X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c6eb7b7703ac4b3401b74f411c8c51ded214bf19;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git [PATCH] s390: deadlock in dasd_devmap Reintroduce a read-only copy of the devmap features in the device struct. This is necessary to solve a deadlock on the dasd_devmap_lock which is acquired by dasd_get_features called from the dasd tasklet. The current implementation of devmap doesn't allow to call any devmap function from interrupt or softirq context. Signed-off-by: Horst Hummel Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index d5f53980749b..8fc891a9d47f 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -7,7 +7,7 @@ * Bugreports.to..: * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001 * - * $Revision: 1.165 $ + * $Revision: 1.167 $ */ #include @@ -1131,17 +1131,13 @@ __dasd_process_blk_queue(struct dasd_device * device) request_queue_t *queue; struct request *req; struct dasd_ccw_req *cqr; - int nr_queued, feature_ro; + int nr_queued; queue = device->request_queue; /* No queue ? Then there is nothing to do. */ if (queue == NULL) return; - feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY); - if (feature_ro < 0) /* no devmap */ - return; - /* * We requeue request from the block device queue to the ccw * queue only in two states. In state DASD_STATE_READY the @@ -1162,7 +1158,8 @@ __dasd_process_blk_queue(struct dasd_device * device) nr_queued < DASD_CHANQ_MAX_SIZE) { req = elv_next_request(queue); - if (feature_ro && rq_data_dir(req) == WRITE) { + if (device->features & DASD_FEATURE_READONLY && + rq_data_dir(req) == WRITE) { DBF_DEV_EVENT(DBF_ERR, device, "Rejecting write request %p", req); @@ -1814,17 +1811,13 @@ dasd_generic_set_online (struct ccw_device *cdev, { struct dasd_device *device; - int feature_diag, rc; + int rc; device = dasd_create_device(cdev); if (IS_ERR(device)) return PTR_ERR(device); - feature_diag = dasd_get_feature(cdev, DASD_FEATURE_USEDIAG); - if (feature_diag < 0) - return feature_diag; - - if (feature_diag) { + if (device->features & DASD_FEATURE_USEDIAG) { if (!dasd_diag_discipline_pointer) { printk (KERN_WARNING "dasd_generic couldn't online device %s " diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index d948566bb24a..bda896d9d788 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -11,7 +11,7 @@ * functions may not be called from interrupt context. In particular * dasd_get_device is a no-no from interrupt context. * - * $Revision: 1.40 $ + * $Revision: 1.43 $ */ #include @@ -513,6 +513,7 @@ dasd_create_device(struct ccw_device *cdev) if (!devmap->device) { devmap->device = device; device->devindex = devmap->devindex; + device->features = devmap->features; get_device(&cdev->dev); device->cdev = cdev; rc = 0; @@ -643,6 +644,8 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr, const char *buf devmap->features |= DASD_FEATURE_READONLY; else devmap->features &= ~DASD_FEATURE_READONLY; + if (devmap->device) + devmap->device->features = devmap->features; if (devmap->device && devmap->device->gdp) set_disk_ro(devmap->device->gdp, ro_flag); spin_unlock(&dasd_devmap_lock); @@ -758,7 +761,8 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag) devmap->features |= feature; else devmap->features &= ~feature; - + if (devmap->device) + devmap->device->features = devmap->features; spin_unlock(&dasd_devmap_lock); return 0; } diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c index 96c49349701f..a601c9a33541 100644 --- a/drivers/s390/block/dasd_genhd.c +++ b/drivers/s390/block/dasd_genhd.c @@ -9,7 +9,7 @@ * * gendisk related functions for the dasd driver. * - * $Revision: 1.50 $ + * $Revision: 1.51 $ */ #include @@ -31,16 +31,12 @@ int dasd_gendisk_alloc(struct dasd_device *device) { struct gendisk *gdp; - int len, feature_ro; + int len; /* Make sure the minor for this device exists. */ if (device->devindex >= DASD_PER_MAJOR) return -EBUSY; - feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY); - if (feature_ro < 0) - return feature_ro; - gdp = alloc_disk(1 << DASD_PARTN_BITS); if (!gdp) return -ENOMEM; @@ -75,7 +71,7 @@ dasd_gendisk_alloc(struct dasd_device *device) sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id); - if (feature_ro) + if (device->features & DASD_FEATURE_READONLY) set_disk_ro(gdp, 1); gdp->private_data = device; gdp->queue = device->request_queue; diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index a9f38b235981..9fab04f3056d 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -6,7 +6,7 @@ * Bugreports.to..: * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000 * - * $Revision: 1.64 $ + * $Revision: 1.65 $ */ #ifndef DASD_INT_H @@ -286,6 +286,7 @@ struct dasd_device { unsigned int bp_block; /* bytes per block */ unsigned int s2b_shift; /* log2 (bp_block/512) */ unsigned long flags; /* per device flags */ + unsigned short features; /* copy of devmap-features (read-only!) */ /* Device discipline stuff. */ struct dasd_discipline *discipline; diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c index 980c555aa538..789595b3fa09 100644 --- a/drivers/s390/block/dasd_ioctl.c +++ b/drivers/s390/block/dasd_ioctl.c @@ -7,7 +7,7 @@ * Bugreports.to..: * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001 * - * $Revision: 1.45 $ + * $Revision: 1.47 $ * * i/o controls for the dasd driver. */ @@ -296,7 +296,6 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args) { struct dasd_device *device; struct format_data_t fdata; - int feature_ro; if (!capable(CAP_SYS_ADMIN)) return -EACCES; @@ -308,10 +307,7 @@ dasd_ioctl_format(struct block_device *bdev, int no, long args) if (device == NULL) return -ENODEV; - feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY); - if (feature_ro < 0) - return feature_ro; - if (feature_ro) + if (device->features & DASD_FEATURE_READONLY) return -EROFS; if (copy_from_user(&fdata, (void __user *) args, sizeof (struct format_data_t))) @@ -384,7 +380,7 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args) struct dasd_device *device; struct dasd_information2_t *dasd_info; unsigned long flags; - int rc, feature_ro; + int rc; struct ccw_device *cdev; device = bdev->bd_disk->private_data; @@ -394,10 +390,6 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args) if (!device->discipline->fill_info) return -EINVAL; - feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY); - if (feature_ro < 0) - return feature_ro; - dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL); if (dasd_info == NULL) return -ENOMEM; @@ -427,7 +419,8 @@ dasd_ioctl_information(struct block_device *bdev, int no, long args) (dasd_check_blocksize(device->bp_block))) dasd_info->format = DASD_FORMAT_NONE; - dasd_info->features |= feature_ro; + dasd_info->features |= + ((device->features & DASD_FEATURE_READONLY) != 0); if (device->discipline) memcpy(dasd_info->type, device->discipline->name, 4); diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c index 43c34f8c5e68..fff9020d4886 100644 --- a/drivers/s390/block/dasd_proc.c +++ b/drivers/s390/block/dasd_proc.c @@ -9,7 +9,7 @@ * * /proc interface for the dasd driver. * - * $Revision: 1.32 $ + * $Revision: 1.33 $ */ #include @@ -55,7 +55,6 @@ dasd_devices_show(struct seq_file *m, void *v) { struct dasd_device *device; char *substr; - int feature; device = dasd_device_from_devindex((unsigned long) v - 1); if (IS_ERR(device)) @@ -79,10 +78,7 @@ dasd_devices_show(struct seq_file *m, void *v) else seq_printf(m, " is ????????"); /* Print devices features. */ - feature = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY); - if (feature < 0) - return 0; - substr = feature ? "(ro)" : " "; + substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " "; seq_printf(m, "%4s: ", substr); /* Print device status information. */ switch ((device != NULL) ? device->state : -1) {