From 8741ce6d114873e482b1ef298d6537d18ff393d3 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Wed, 1 Apr 2015 18:49:11 +0200 Subject: s390/mm: Fix memory hotplug for unaligned standby memory Commit 27356f54c8c3 ("mm/hotplug: verify hotplug memory range") introduced a check that makes add_memory() only accept section size aligned memory. Therefore on z/VM systems, where standby memory is not aligned, no standby memory is registered at all. Example: #cp def store 3504M standby 2336M 00: CP Q V STORE 00: STORAGE = 3504M MAX = 6G INC = 8M STANDBY = 2336M RESERVED = 0 For this setup the following error message is printed: Section-unaligned hotplug range: start 0xdb000000, size 0x92000000 So fix this and register aligned memory in "sclp_cmd.c". This means that for the corner cases where the standby memory is not aligned we loose some memory. In order to inform the user about the potential loss of standby memory, we add a new message for each added standby block and print how much of the standby memory is usable, for example: sclp_cmd.4336b4: Standby memory at 0x50000000 (256M of 256M usable) sclp_cmd.4336b4: Standby memory at 0xb0000000 (256M of 256M usable) sclp_cmd.4336b4: Standby memory at 0xdb000000 (2048M of 2336M usable) We also ensure that a potential memory block that contains both "assigned" and "standby" memory cannot be setup offline. Reviewed-by: Gerald Schaefer Reviewed-by: Heiko Carstens Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- drivers/s390/char/sclp_cmd.c | 48 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 46 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c index 6e14999f9e8f..7be782116dab 100644 --- a/drivers/s390/char/sclp_cmd.c +++ b/drivers/s390/char/sclp_cmd.c @@ -315,10 +315,29 @@ static int sclp_mem_change_state(unsigned long start, unsigned long size, rc |= sclp_assign_storage(incr->rn); else sclp_unassign_storage(incr->rn); + if (rc == 0) + incr->standby = online ? 0 : 1; } return rc ? -EIO : 0; } +static bool contains_standby_increment(unsigned long start, unsigned long end) +{ + struct memory_increment *incr; + unsigned long istart; + + list_for_each_entry(incr, &sclp_mem_list, list) { + istart = rn2addr(incr->rn); + if (end - 1 < istart) + continue; + if (start > istart + sclp_rzm - 1) + continue; + if (incr->standby) + return true; + } + return false; +} + static int sclp_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) { @@ -334,8 +353,16 @@ static int sclp_mem_notifier(struct notifier_block *nb, for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1) sclp_attach_storage(id); switch (action) { - case MEM_ONLINE: case MEM_GOING_OFFLINE: + /* + * We do not allow to set memory blocks offline that contain + * standby memory. This is done to simplify the "memory online" + * case. + */ + if (contains_standby_increment(start, start + size)) + rc = -EPERM; + break; + case MEM_ONLINE: case MEM_CANCEL_OFFLINE: break; case MEM_GOING_ONLINE: @@ -361,6 +388,21 @@ static struct notifier_block sclp_mem_nb = { .notifier_call = sclp_mem_notifier, }; +static void __init align_to_block_size(unsigned long long *start, + unsigned long long *size) +{ + unsigned long long start_align, size_align, alignment; + + alignment = memory_block_size_bytes(); + start_align = roundup(*start, alignment); + size_align = rounddown(*start + *size, alignment) - start_align; + + pr_info("Standby memory at 0x%llx (%lluM of %lluM usable)\n", + *start, size_align >> 20, *size >> 20); + *start = start_align; + *size = size_align; +} + static void __init add_memory_merged(u16 rn) { static u16 first_rn, num; @@ -382,7 +424,9 @@ static void __init add_memory_merged(u16 rn) goto skip_add; if (memory_end_set && (start + size > memory_end)) size = memory_end - start; - add_memory(0, start, size); + align_to_block_size(&start, &size); + if (size) + add_memory(0, start, size); skip_add: first_rn = rn; num = 1; -- cgit v1.2.3 From f2608cd4a37479d11d0748f524a6a363ee38631f Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Thu, 2 Apr 2015 12:27:25 +0200 Subject: s390/dasd: fix inability to set a DASD device offline Fix ref counting for DASD devices leading to an inability to set a DASD device offline. Before a worker is scheduled the DASD device driver takes a reference to the device. If the worker was already scheduled this reference was never freed. Fix by giving the reference to the DASD device free when schedule_work() returns false. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 9 ++++++--- drivers/s390/block/dasd_eckd.c | 3 ++- 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 26a51dc4278d..cd57857a1c84 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -579,7 +579,8 @@ void dasd_kick_device(struct dasd_device *device) { dasd_get_device(device); /* queue call to dasd_kick_device to the kernel event daemon. */ - schedule_work(&device->kick_work); + if (!schedule_work(&device->kick_work)) + dasd_put_device(device); } EXPORT_SYMBOL(dasd_kick_device); @@ -599,7 +600,8 @@ void dasd_reload_device(struct dasd_device *device) { dasd_get_device(device); /* queue call to dasd_reload_device to the kernel event daemon. */ - schedule_work(&device->reload_device); + if (!schedule_work(&device->reload_device)) + dasd_put_device(device); } EXPORT_SYMBOL(dasd_reload_device); @@ -619,7 +621,8 @@ void dasd_restore_device(struct dasd_device *device) { dasd_get_device(device); /* queue call to dasd_restore_device to the kernel event daemon. */ - schedule_work(&device->restore_device); + if (!schedule_work(&device->restore_device)) + dasd_put_device(device); } /* diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 49b48a887c66..6215f6455eb8 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -1628,7 +1628,8 @@ static void dasd_eckd_kick_validate_server(struct dasd_device *device) return; } /* queue call to do_validate_server to the kernel event daemon. */ - schedule_work(&device->kick_validate); + if (!schedule_work(&device->kick_validate)) + dasd_put_device(device); } static u32 get_fcx_max_data(struct dasd_device *device) -- cgit v1.2.3 From a3147a7bc266df39b4f471ee7c4c9adcb56d29a6 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Thu, 2 Apr 2015 12:52:41 +0200 Subject: s390/dasd: fix unresumed device after suspend/resume The DASD device driver only has a limited amount of memory to build I/O requests. This memory was used by blocklayer requests leading to an inability to build needed internal requests to resume the device. Fix by preventing the DASD driver to fetch requests for a stopped device. Signed-off-by: Stefan Haberland Reference-ID: RQM 2520 Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index cd57857a1c84..a5ed35d0cbf3 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2527,6 +2527,11 @@ static void __dasd_process_request_queue(struct dasd_block *block) __blk_end_request_all(req, -EIO); return; } + + /* if device ist stopped do not fetch new requests */ + if (basedev->stopped) + return; + /* Now we try to fetch requests from the request queue */ while ((req = blk_peek_request(queue))) { if (basedev->features & DASD_FEATURE_READONLY && -- cgit v1.2.3 From df3044f1ef002c2269b11cb76a1b2bec629732b4 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Thu, 2 Apr 2015 13:18:39 +0200 Subject: s390/dasd: Fix unresumed device after suspend/resume having no paths The DASD device driver prevents I/O from being started on stopped devices. This also prevented channel paths to be verified and so the device was unable to be resumed. Fix by allowing path verification requests on stopped devices. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index a5ed35d0cbf3..57fd66357b95 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -2166,18 +2166,22 @@ static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible) cqr->intrc = -ENOLINK; continue; } - /* Don't try to start requests if device is stopped */ - if (interruptible) { - rc = wait_event_interruptible( - generic_waitq, !(device->stopped)); - if (rc == -ERESTARTSYS) { - cqr->status = DASD_CQR_FAILED; - maincqr->intrc = rc; - continue; - } - } else - wait_event(generic_waitq, !(device->stopped)); - + /* + * Don't try to start requests if device is stopped + * except path verification requests + */ + if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) { + if (interruptible) { + rc = wait_event_interruptible( + generic_waitq, !(device->stopped)); + if (rc == -ERESTARTSYS) { + cqr->status = DASD_CQR_FAILED; + maincqr->intrc = rc; + continue; + } + } else + wait_event(generic_waitq, !(device->stopped)); + } if (!cqr->callback) cqr->callback = dasd_wakeup_cb; -- cgit v1.2.3