From 6fca97a958bc3c67566aa91eafc6a5be2e66d6b3 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Tue, 6 Oct 2009 10:34:15 +0200 Subject: [S390] dasd: fix race condition in resume code There is a race while re-reading the device characteristics. After cleaning the memory area a cqr is build which reads the device characteristics. This may take a rather long time and the device characteristics structure is zero during this. Now it could be possible that the block tasklet starts working and a new cqr will be build. The build_cp command refers to the device characteristics structure and this may lead into a divide by zero exception. Fix this by re-reading the device characteristics into a temporary structur and copy the data to the original structure. Also take the ccwdev_lock. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 5 +++-- drivers/s390/block/dasd_eckd.c | 9 +++++++-- 2 files changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/s390/block') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index dad0449475b6..53b8c255360a 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2508,8 +2508,6 @@ int dasd_generic_restore_device(struct ccw_device *cdev) device->stopped &= ~DASD_UNRESUMED_PM; dasd_schedule_device_bh(device); - if (device->block) - dasd_schedule_block_bh(device->block); if (device->discipline->restore) rc = device->discipline->restore(device); @@ -2520,6 +2518,9 @@ int dasd_generic_restore_device(struct ccw_device *cdev) */ device->stopped |= DASD_UNRESUMED_PM; + if (device->block) + dasd_schedule_block_bh(device->block); + dasd_put_device(device); return 0; } diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index ab3521755588..0be7c15f45c5 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -2338,6 +2338,8 @@ static struct dasd_ccw_req *dasd_eckd_build_cp(struct dasd_device *startdev, /* Calculate number of blocks/records per track. */ blksize = block->bp_block; blk_per_trk = recs_per_track(&private->rdc_data, 0, blksize); + if (blk_per_trk == 0) + return ERR_PTR(-EINVAL); /* Calculate record id of first and last block. */ first_rec = first_trk = blk_rq_pos(req) >> block->s2b_shift; first_offs = sector_div(first_trk, blk_per_trk); @@ -3211,6 +3213,7 @@ int dasd_eckd_pm_freeze(struct dasd_device *device) int dasd_eckd_restore_device(struct dasd_device *device) { struct dasd_eckd_private *private; + struct dasd_eckd_characteristics temp_rdc_data; int is_known, rc; struct dasd_uid temp_uid; @@ -3245,15 +3248,17 @@ int dasd_eckd_restore_device(struct dasd_device *device) dasd_eckd_read_features(device); /* Read Device Characteristics */ - memset(&private->rdc_data, 0, sizeof(private->rdc_data)); rc = dasd_generic_read_dev_chars(device, DASD_ECKD_MAGIC, - &private->rdc_data, 64); + &temp_rdc_data, 64); if (rc) { DBF_EVENT(DBF_WARNING, "Read device characteristics failed, rc=%d for " "device: %s", rc, dev_name(&device->cdev->dev)); goto out_err; } + spin_lock(get_ccwdev_lock(device->cdev)); + memcpy(&private->rdc_data, &temp_rdc_data, sizeof(temp_rdc_data)); + spin_unlock(get_ccwdev_lock(device->cdev)); /* add device to alias management */ dasd_alias_add_device(device); -- cgit v1.2.2 From a7602f6c16b2de2962b279980693ad1b3711e84a Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Wed, 14 Oct 2009 12:43:46 +0200 Subject: [S390] dasd: fix locking bug Replace spin_lock with spin_lock_irqsave in dasd_eckd_restore_device. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd_eckd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/s390/block') diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 0be7c15f45c5..417b97cd3f94 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -3216,6 +3216,7 @@ int dasd_eckd_restore_device(struct dasd_device *device) struct dasd_eckd_characteristics temp_rdc_data; int is_known, rc; struct dasd_uid temp_uid; + unsigned long flags; private = (struct dasd_eckd_private *) device->private; @@ -3228,7 +3229,8 @@ int dasd_eckd_restore_device(struct dasd_device *device) rc = dasd_eckd_generate_uid(device, &private->uid); dasd_get_uid(device->cdev, &temp_uid); if (memcmp(&private->uid, &temp_uid, sizeof(struct dasd_uid)) != 0) - dev_err(&device->cdev->dev, "The UID of the DASD has changed\n"); + dev_err(&device->cdev->dev, "The UID of the DASD has " + "changed\n"); if (rc) goto out_err; dasd_set_uid(device->cdev, &private->uid); @@ -3256,9 +3258,9 @@ int dasd_eckd_restore_device(struct dasd_device *device) "device: %s", rc, dev_name(&device->cdev->dev)); goto out_err; } - spin_lock(get_ccwdev_lock(device->cdev)); + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); memcpy(&private->rdc_data, &temp_rdc_data, sizeof(temp_rdc_data)); - spin_unlock(get_ccwdev_lock(device->cdev)); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); /* add device to alias management */ dasd_alias_add_device(device); -- cgit v1.2.2 From d9fa9441ed6e0467d7d41de730581874c997e658 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Wed, 14 Oct 2009 12:43:48 +0200 Subject: [S390] dasd: use idal for device characteristics If the rdc_buffer is above 2G we need indirect addresssing so we have to use an idaw to give the rdc_buffer to the ccw. If the rdc_buffer is under 2G nothing changes. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'drivers/s390/block') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 53b8c255360a..aaccc8ecfa8f 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2533,6 +2533,7 @@ static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device, { struct dasd_ccw_req *cqr; struct ccw1 *ccw; + unsigned long *idaw; cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device); @@ -2546,9 +2547,17 @@ static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device, ccw = cqr->cpaddr; ccw->cmd_code = CCW_CMD_RDC; - ccw->cda = (__u32)(addr_t)rdc_buffer; - ccw->count = rdc_buffer_size; + if (idal_is_needed(rdc_buffer, rdc_buffer_size)) { + idaw = (unsigned long *) (cqr->data); + ccw->cda = (__u32)(addr_t) idaw; + ccw->flags = CCW_FLAG_IDA; + idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size); + } else { + ccw->cda = (__u32)(addr_t) rdc_buffer; + ccw->flags = 0; + } + ccw->count = rdc_buffer_size; cqr->startdev = device; cqr->memdev = device; cqr->expires = 10*HZ; -- cgit v1.2.2