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* nvme-rdma: Allow DELETING state change failure in error_recoveryNitzan Carmi2018-03-261-2/+2
| | | | | | | | | | | | While error recovery is ongoing, it is OK to move ctrl to DELETING state (from concurrent delete_work). Thus we don't need a warning for that case. Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: Skip checking heads without namespacesKeith Busch2018-03-261-0/+1
| | | | | | | | | | | | | | | | | If a task is holding a reference to a namespace on a removed controller, the head will not be released. If the same controller is added again later, its namespaces may not be successfully added. Instead, the user will see kernel message "Duplicate IDs for nsid <X>". This patch fixes that by skipping heads that don't have namespaces when considering if a new namespace is safe to add. Reported-by: Alex Gagniuc <Alex_Gagniuc@Dellteam.com> Cc: stable@vger.kernel.org Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme-rdma: Don't flush delete_wq by default during remove_oneMax Gurtovoy2018-03-261-0/+14
| | | | | | | | | | | | The .remove_one function is called for any ib_device removal. In case the removed device has no reference in our driver, there is no need to flush the work queue. Reviewed-by: Israel Rukshin <israelr@mellanox.com> Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvmet-rdma: Don't flush system_wq by default during remove_oneMax Gurtovoy2018-03-261-1/+18
| | | | | | | | | | | | The .remove_one function is called for any ib_device removal. In case the removed device has no reference in our driver, there is no need to flush the system work queue. Reviewed-by: Israel Rukshin <israelr@mellanox.com> Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvmet-rdma: Fix use after free in nvmet_rdma_cm_handler()Israel Rukshin2018-03-261-16/+11Star
| | | | | | | | | | | We free nvmet rdma queues while handling rdma_cm events. In order to avoid this we destroy the qp and the queue after destroying the cm_id which guarantees that all rdma_cm events are done. Signed-off-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvmet-rdma: Remove unused queue stateIsrael Rukshin2018-03-261-5/+1Star
| | | | | | | Signed-off-by: Israel Rukshin <israelr@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvmet_fc: prevent new io rqsts in possible isr completionsJames Smart2018-03-261-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | When a bio completion calls back into the transport for a back-end io device, the request completion path can free the transport io job structure allowing it to be reused for other operations. The transport has a defer_rcv queue which holds temporary cmd rcv ops while waitng for io job structures. when the job frees, if there's a cmd waiting, it is picked up and submitted for processing, which can call back out to the bio path if it's a read. Unfortunately, what is unknown is the context of the original bio done call, and it may be in a state (softirq) that is not compatible with submitting the new bio in the same calling sequence. This is especially true when using scsi back-end devices as scsi is in softirq when it makes the done call. Correct by scheduling the io to be started via workq rather than calling the start new io path inline to the original bio done path. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme_fc: on remoteport reuse, set new nport_id and role.James Smart2018-03-261-0/+2
| | | | | | | | | | When reattaching to a removed remoteport that has not yet been fully deleted as it's waiting for reconnect timeouts, be sure to re-set the ports nport id and role. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme_fc: fix abort race on teardown with lld rejectJames Smart2018-03-261-1/+4
| | | | | | | | | | | | | | | | | | | | Another abort race: An io request is started, becomes active, and is attempted to be started with the lldd. At the same time the controller is stopped/torndown and an itterator is run to abort the ios. As the io is active, it is added to the outstanding aborted io count. However on the original io request thread, the driver ends up rejecting the io due to the condition that induced the controller teardown. The driver reject path didn't check whether it was in the outstanding io count. This left the count outstanding stopping controller teardown. Correct by, in the driver reject case, setting the state to inactive and checking whether it was in the outstanding io count. Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme_fc: io timeout should defer abort to ctrl resetJames Smart2018-03-261-11/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | The current nvme_fc code, when an io times out, will abort the io on the fc link, then call the error recovery routine to reset the controller. It is during the reset of the controller that the transport will wait for all ios to be aborted before sending a Disconnect LS to the target. However, the reset routine only waits for the io which it generates the abort for to complete. Any io that was aborted just prior to the reset isn't in it's list to wait for. Thus the Disconnect is getting sent before the aborts have completed. Correct by removing the abort in the timeout handler. The reset will generate the abort. At that point the timeout handler can be simplified to request the reset (via the error handler) and restart the timeout timer. Also fixes a small typo in a comment in the reset handler. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme_fc: fix ctrl create failures racing with workq itemsJames Smart2018-03-261-0/+4
| | | | | | | | | | | | | | | | | | | If there are errors during initial controller create, the transport will teardown the partially initialized controller struct and free the ctlr memory. Trouble is - most of those errors can occur due to asynchronous events happening such io timeouts and subsystem connectivity failures. Those failures invoke async workq items to reset the controller and attempt reconnect. Those may be in progress as the main thread frees the ctrl memory, resulting in NULL ptr oops. Prevent this from happening by having the main ctrl failure thread changing state to DELETING followed by synchronously cancelling any pending queued work item. The change of state will prevent the scheduling of resets or reconnect events. Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme-pci: disable APST for Samsung NVMe SSD 960 EVO + ASUS PRIME Z370-AJarosław Janik2018-03-261-2/+5
| | | | | | | | | | | | | | | Yet another "incompatible" Samsung NVMe SSD 960 EVO and Asus motherboard combination. 960 EVO device disappears from PCIe bus within few minutes after boot-up when APST is in use and never gets back. Forcing NVME_QUIRK_NO_APST is the only way to make this drive work with this particular motherboard. NVME_QUIRK_NO_DEEPEST_PS doesn't work, upgrading motherboard's BIOS didn't help either. Since this is a desktop motherboard, the only drawback of not using APST is increased device temperature. Signed-off-by: Jarosław Janik <jaroslaw.janik@gmail.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: centralize ctrl removal printsMax Gurtovoy2018-03-263-12/+8Star
| | | | | | | | | | | | nvme_delete_ctrl can be called from various contexts in parallel, and cause duplicated information prints, even though the specific context doesn't perform the actual removal. Instead, print the information when the actual removal occurs. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme-pci: Add .get_address ctrl callbackKeith Busch2018-03-261-0/+8
| | | | | | | | | | | The nvme-fabrics exports the controller address to sysfs, and we'd like to have parity with this feature for PCIe. This patch provides the appropiate callback and returns the controller address as the pci domain:bus:device.function. Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: implement log page low/high offset and dwordsMatias Bjørling2018-03-261-10/+22
| | | | | | | | | | | NVMe 1.2.1 extends the get log page interface to include 64 bit offset and increases the number of dwords to 32 bits. Implement for future use. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: change namespaces_mutext to namespaces_rwsemJianchao Wang2018-03-263-35/+35
| | | | | | | | | | | | | | | | | | | | | namespaces_mutext is used to synchronize the operations on ctrl namespaces list. Most of the time, it is a read operation. On the other hand, there are many interfaces in nvme core that need this lock, such as nvme_wait_freeze, and even more interfaces will be added. If we use mutex here, circular dependency could be introduced easily. For example: context A context B nvme_xxx nvme_xxx hold namespaces_mutext require namespaces_mutext sync context B So it is better to change it from mutex to rwsem. Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: fix the dangerous reference of namespaces listJianchao Wang2018-03-261-2/+14
| | | | | | | | | | | | | | nvme_remove_namespaces and nvme_remove_invalid_namespaces reference the ctrl->namespaces list w/o holding namespaces_mutext. It is ok to invoke nvme_ns_remove there, but what if there is others. To be safer, reference the ctrl->namespaces list under namespaces_mutext. Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme-pci: quiesce IO queues prior to disabling device HMB accessesJianchao Wang2018-03-261-5/+4Star
| | | | | | | | | | | Quiesce IO queues prior to disabling device HMB accesses. A controller using HMB may relay on it to efficiently complete IO commands. Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Documentation: nvme: Documentation for nvme fault injectionThomas Tai2018-03-262-0/+124
| | | | | | | | | | | Add examples to show how to use nvme fault injection. Signed-off-by: Thomas Tai <thomas.tai@oracle.com> Reviewed-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com> Signed-off-by: Karl Volz <karl.volz@oracle.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: Add fault injection featureThomas Tai2018-03-264-0/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux's fault injection framework provides a systematic way to support error injection via debugfs in the /sys/kernel/debug directory. This patch uses the framework to add error injection to NVMe driver. The fault injection source code is stored in a separate file and only linked if CONFIG_FAULT_INJECTION_DEBUG_FS kernel config is selected. Once the error injection is enabled, NVME_SC_INVALID_OPCODE with no retry will be injected into the nvme_end_request. Users can change the default status code and no retry flag via debufs. Following example shows how to enable and inject an error. For more examples, refer to Documentation/fault-injection/nvme-fault-injection.txt How to enable nvme fault injection: First, enable CONFIG_FAULT_INJECTION_DEBUG_FS kernel config, recompile the kernel. After booting up the kernel, do the following. How to inject an error: mount /dev/nvme0n1 /mnt echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability cp a.file /mnt Expected Result: cp: cannot stat ‘/mnt/a.file’: Input/output error Message from dmesg: FAULT_INJECTION: forcing a failure. name fault_inject, interval 1, probability 100, space 0, times 1 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc8+ #2 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 Call Trace: <IRQ> dump_stack+0x5c/0x7d should_fail+0x148/0x170 nvme_should_fail+0x2f/0x50 [nvme_core] nvme_process_cq+0xe7/0x1d0 [nvme] nvme_irq+0x1e/0x40 [nvme] __handle_irq_event_percpu+0x3a/0x190 handle_irq_event_percpu+0x30/0x70 handle_irq_event+0x36/0x60 handle_fasteoi_irq+0x78/0x120 handle_irq+0xa7/0x130 ? tick_irq_enter+0xa8/0xc0 do_IRQ+0x43/0xc0 common_interrupt+0xa2/0xa2 </IRQ> RIP: 0010:native_safe_halt+0x2/0x10 RSP: 0018:ffffffff82003e90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd RAX: ffffffff817a10c0 RBX: ffffffff82012480 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 000000008e38ce64 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82012480 R13: ffffffff82012480 R14: 0000000000000000 R15: 0000000000000000 ? __sched_text_end+0x4/0x4 default_idle+0x18/0xf0 do_idle+0x150/0x1d0 cpu_startup_entry+0x6f/0x80 start_kernel+0x4c4/0x4e4 ? set_init_arg+0x55/0x55 secondary_startup_64+0xa5/0xb0 print_req_error: I/O error, dev nvme0n1, sector 9240 EXT4-fs error (device nvme0n1): ext4_find_entry:1436: inode #2: comm cp: reading directory lblock 0 Signed-off-by: Thomas Tai <thomas.tai@oracle.com> Reviewed-by: Eric Saint-Etienne <eric.saint.etienne@oracle.com> Signed-off-by: Karl Volz <karl.volz@oracle.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvme: use define instead of magic value for identify sizeMinwoo Im2018-03-261-2/+3
| | | | | | | | | | | | | NVME_IDENTIFY_DATA_SIZE was added to linux/nvme.h by following commit. commit 0add5e8e588c ("nvmet: use NVME_IDENTIFY_DATA_SIZE") Make it use NVME_IDENTIFY_DATA_SIZE define instead of magic value 0x1000 in case of identify data size. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* iscsi-target: use common inet_addr_is_anySagi Grimberg2018-03-261-26/+2Star
| | | | | | | | | | | Instead of open-coding it. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: target-devel@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* nvmet: don't return "any" ip address in discovery log pageSagi Grimberg2018-03-263-3/+47
| | | | | | | | | | | | | | | | | Its perfectly valid to assign a nvmet port to listen on "any" IP address (traddr 0.0.0.0 for ipv4 address family) for IP based transport ports. However, we must not return this address in discovery log entries. Instead we need to return the address where the request was accepted on (req->port address). Since this is nvme transport specific, introduce an optional .disc_traddr interface that is designed to check that a port in question is bound to "any" IP address and if so, set the traddr from the port where the request came from. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* net/utils: Introduce inet_addr_is_anySagi Grimberg2018-03-262-0/+24
| | | | | | | | | | Can be useful to check INET_ANY address for both ipv4/ipv6 addresses. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* mmc: block: Delete gendisk before cleaning up the request queueShawn Lin2018-03-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dd if=/dev/urandom of=/dev/mmcblk1 bs=4k count=10000 with a SD card hotplug during transfer reports a warning below introduced by commit a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller"). So we should now remove the disk, partition and bdi sysfs attributes before cleaning up the request queue associated with the disk. [ 410.331226] mmc1: card 59b4 removed [ 410.348583] WARNING: CPU: 0 PID: 5 at block/blk-core.c:785 blk_cleanup_queue+0x138/0x140 [ 410.349294] Modules linked in: [ 410.349570] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 4.16.0-rc6-next-20180321-00004-gc2ad6a7 #263 [ 410.350363] Hardware name: Excavator-RK3399 Board (DT) [ 410.350819] Workqueue: events_freezable mmc_rescan [ 410.351242] pstate: 60000005 (nZCv daif -PAN -UAO) [ 410.351663] pc : blk_cleanup_queue+0x138/0x140 [ 410.352054] lr : blk_cleanup_queue+0xac/0x140 [ 410.352436] sp : ffff0000092cbb90 [ 410.352727] x29: ffff0000092cbb90 x28: 0000000000000000 [ 410.353195] x27: ffff8000f6f23030 x26: ffff00000904e610 [ 410.353662] x25: ffff8000f17cc808 x24: ffff8000f1038200 [ 410.354128] x23: 0000000000000060 x22: 0000000000000000 [ 410.354595] x21: ffff8000f11748d8 x20: ffff8000f1038200 [ 410.355061] x19: ffff8000f1174200 x18: 0000ffff936347d8 [ 410.355528] x17: 0000ffff935b93c0 x16: ffff0000081263f8 [ 410.355994] x15: 0000000000000000 x14: 0000000000000400 [ 410.356461] x13: 0000000000000001 x12: 0000000000000001 [ 410.356927] x11: 0000000000000040 x10: ffff8000f2400028 [ 410.357393] x9 : ffff8000f2400040 x8 : 0000000000000000 [ 410.357860] x7 : ffff8000f6f3a340 x6 : ffff8000f6f3a340 [ 410.358326] x5 : ffff8000f2400000 x4 : ffff8000f6f3a340 [ 410.358792] x3 : 0000000000000000 x2 : 39c1333e45670800 [ 410.359259] x1 : 0000000000000000 x0 : 0000000000000003 [ 410.359726] Call trace: [ 410.359943] blk_cleanup_queue+0x138/0x140 [ 410.360305] mmc_cleanup_queue+0x2c/0x48 [ 410.360652] mmc_blk_remove_req+0x1c/0x98 [ 410.361005] mmc_blk_remove+0x180/0x1c0 [ 410.361343] mmc_bus_remove+0x1c/0x28 [ 410.361670] device_release_driver_internal+0x154/0x1f0 [ 410.362128] device_release_driver+0x14/0x20 [ 410.362504] bus_remove_device+0xc8/0x108 [ 410.362858] device_del+0x120/0x350 [ 410.363167] mmc_remove_card+0x5c/0xb8 [ 410.363498] mmc_sd_detect+0x40/0x78 [ 410.363813] mmc_rescan+0x19c/0x368 [ 410.364123] process_one_work+0x1ac/0x318 [ 410.364477] worker_thread+0x50/0x450 [ 410.364801] kthread+0xf8/0x128 [ 410.365081] ret_from_fork+0x10/0x18 [ 410.365395] ---[ end trace 268e87a46c28968c ]--- Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Fix slab name "biovec-(1<<(21-12))"Mikulas Patocka2018-03-221-2/+2
| | | | | | | | | I'm getting a slab named "biovec-(1<<(21-12))". It is caused by unintended expansion of the macro BIO_MAX_PAGES. This patch renames it to biovec-max. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: use 32-bit blk_status_t on AlphaMikulas Patocka2018-03-221-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | Early alpha processors cannot write a single byte or word; they read 8 bytes, modify the value in registers and write back 8 bytes. The type blk_status_t is defined as one byte, it is often written asynchronously by I/O completion routines, this asynchronous modification can corrupt content of nearby bytes if these nearby bytes can be written simultaneously by another CPU. - one example of such corruption is the structure dm_io where "blk_status_t status" is written by an asynchronous completion routine and "atomic_t io_count" is modified synchronously - another example is the structure dm_buffer where "unsigned hold_count" is modified synchronously from process context and "blk_status_t write_error" is modified asynchronously from bio completion routine This patch fixes the bug by changing the type blk_status_t to 32 bits if we are on Alpha and if we are compiling for a processor that doesn't have the byte-word-extension. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Change a rcu_read_{lock,unlock}_sched() pair into ↵Bart Van Assche2018-03-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rcu_read_{lock,unlock}() scsi_device_quiesce() uses synchronize_rcu() to guarantee that the effect of blk_set_preempt_only() will be visible for percpu_ref_tryget() calls that occur after the queue unfreeze by using the approach explained in https://lwn.net/Articles/573497/. The rcu read lock and unlock calls in blk_queue_enter() form a pair with the synchronize_rcu() call in scsi_device_quiesce(). Both scsi_device_quiesce() and blk_queue_enter() must either use regular RCU or RCU-sched. Since neither the RCU-protected code in blk_queue_enter() nor blk_queue_usage_counter_release() sleeps, regular RCU protection is sufficient. Note: scsi_device_quiesce() does not have to be modified since it already uses synchronize_rcu(). Reported-by: Tejun Heo <tj@kernel.org> Fixes: 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Martin Steigerwald <martin@lichtvoll.de> Cc: stable@vger.kernel.org # v4.15 Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Fix a compiler warning in bcache_device_init()Bart Van Assche2018-03-191-3/+3
| | | | | | | | | | | | | Avoid that building with W=1 triggers the following compiler warning: drivers/md/bcache/super.c:776:20: warning: comparison is always false due to limited range of data type [-Wtype-limits] d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) { ^ Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Reduce the number of sparse complaints about lock imbalancesBart Van Assche2018-03-191-0/+2
| | | | | | | | | Add more annotations for sparse to inform it about which functions do not have the same number of spin_lock() and spin_unlock() calls. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Suppress more warnings about set-but-not-used variablesBart Van Assche2018-03-192-3/+3
| | | | | | | | | This patch does not change any functionality. Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Remove an unused variableBart Van Assche2018-03-191-2/+0Star
| | | | | | Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Fix kernel-doc warningsBart Van Assche2018-03-194-15/+14Star
| | | | | | | | | Avoid that building with W=1 triggers warnings about the kernel-doc headers. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Annotate switch fall-throughBart Van Assche2018-03-191-0/+7
| | | | | | | | | This patch avoids that building with W=1 triggers complaints about switch fall-throughs. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Add __printf annotation to __bch_check_keys()Bart Van Assche2018-03-191-2/+3
| | | | | | | | | | Make it possible for the compiler to verify the consistency of the format string passed to __bch_check_keys() and the arguments that should be formatted according to that format string. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: Fix indentationBart Van Assche2018-03-192-2/+2
| | | | | | | | | This patch avoids that smatch complains about inconsistent indentation. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: add io_disable to struct cached_devColy Li2018-03-195-3/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a bcache device is configured to writeback mode, current code does not handle write I/O errors on backing devices properly. In writeback mode, write request is written to cache device, and latter being flushed to backing device. If I/O failed when writing from cache device to the backing device, bcache code just ignores the error and upper layer code is NOT noticed that the backing device is broken. This patch tries to handle backing device failure like how the cache device failure is handled, - Add a error counter 'io_errors' and error limit 'error_limit' in struct cached_dev. Add another io_disable to struct cached_dev to disable I/Os on the problematic backing device. - When I/O error happens on backing device, increase io_errors counter. And if io_errors reaches error_limit, set cache_dev->io_disable to true, and stop the bcache device. The result is, if backing device is broken of disconnected, and I/O errors reach its error limit, backing device will be disabled and the associated bcache device will be removed from system. Changelog: v2: remove "bcache: " prefix in pr_error(), and use correct name string to print out bcache device gendisk name. v1: indeed this is new added in v2 patch set. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: add backing_request_endio() for bi_end_ioColy Li2018-03-193-16/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to catch I/O error of backing device, a separate bi_end_io call back is required. Then a per backing device counter can record I/O errors number and retire the backing device if the counter reaches a per backing device I/O error limit. This patch adds backing_request_endio() to bcache backing device I/O code path, this is a preparation for further complicated backing device failure handling. So far there is no real code logic change, I make this change a separate patch to make sure it is stable and reliable for further work. Changelog: v2: Fix code comments typo, remove a redundant bch_writeback_add() line added in v4 patch set. v1: indeed this is new added in this patch set. [mlyle: truncated commit subject] Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: move closure debug file into debug directoryChengguang Xu2018-03-194-15/+16
| | | | | | | | | | | | | | | In current code closure debug file is outside of debug directory and when unloading module there is lack of removing operation for closure debug file, so it will cause creating error when trying to reload module. This patch move closure debug file into "bcache" debug direcory so that the file can get deleted properly. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: fix using of loop variable in memory shrinkTang Junhui2018-03-191-3/+6
| | | | | | | | | | | | | | | In bch_mca_scan(), There are some confusion and logical error in the use of loop variables. In this patch, we clarify them as: 1) nr: the number of btree nodes needs to scan, which will decrease after we scan a btree node, and should not be less than 0; 2) i: the number of btree nodes have scanned, includes both btree_cache_freeable and btree_cache, which should not be bigger than btree_cache_used; 3) freed: the number of btree nodes have freed. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: fix error return value in memory shrinkTang Junhui2018-03-191-1/+1
| | | | | | | | | In bch_mca_scan(), the return value should not be the number of freed btree nodes, but the number of pages of freed btree nodes. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: fix incorrect sysfs output value of strip sizeTang Junhui2018-03-191-1/+1
| | | | | | | | | | | | | | | | Stripe size is shown as zero when no strip in back end device: [root@ceph132 ~]# cat /sys/block/sdd/bcache/stripe_size 0.0k Actually it should be 1T Bytes (1 << 31 sectors), but in sysfs interface, stripe_size was changed from sectors to bytes, and move 9 bits left, so the 32 bits variable overflows. This patch change the variable to a 64 bits type before moving bits. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: fix inaccurate io state for detached bcache devicesTang Junhui2018-03-191-7/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we run IO in a detached device, and run iostat to shows IO status, normally it will show like bellow (Omitted some fields): Device: ... avgrq-sz avgqu-sz await r_await w_await svctm %util sdd ... 15.89 0.53 1.82 0.20 2.23 1.81 52.30 bcache0 ... 15.89 115.42 0.00 0.00 0.00 2.40 69.60 but after IO stopped, there are still very big avgqu-sz and %util values as bellow: Device: ... avgrq-sz avgqu-sz await r_await w_await svctm %util bcache0 ... 0 5326.32 0.00 0.00 0.00 0.00 100.10 The reason for this issue is that, only generic_start_io_acct() called and no generic_end_io_acct() called for detached device in cached_dev_make_request(). See the code: //start generic_start_io_acct() generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0); if (cached_dev_get(dc)) { //will callback generic_end_io_acct() } else { //will not call generic_end_io_acct() } This patch calls generic_end_io_acct() in the end of IO for detached devices, so we can show IO state correctly. (Modified to use GFP_NOIO in kzalloc() by Coly Li) Changelog: v2: fix typo. v1: the initial version. Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: add stop_when_cache_set_failed option to backing deviceColy Li2018-03-193-10/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there are too many I/O errors on cache device, current bcache code will retire the whole cache set, and detach all bcache devices. But the detached bcache devices are not stopped, which is problematic when bcache is in writeback mode. If the retired cache set has dirty data of backing devices, continue writing to bcache device will write to backing device directly. If the LBA of write request has a dirty version cached on cache device, next time when the cache device is re-registered and backing device re-attached to it again, the stale dirty data on cache device will be written to backing device, and overwrite latest directly written data. This situation causes a quite data corruption. But we cannot simply stop all attached bcache devices when the cache set is broken or disconnected. For example, use bcache to accelerate performance of an email service. In such workload, if cache device is broken but no dirty data lost, keep the bcache device alive and permit email service continue to access user data might be a better solution for the cache device failure. Nix <nix@esperi.org.uk> points out the issue and provides the above example to explain why it might be necessary to not stop bcache device for broken cache device. Pavel Goran <via-bcache@pvgoran.name> provides a brilliant suggestion to provide "always" and "auto" options to per-cached device sysfs file stop_when_cache_set_failed. If cache set is retiring and the backing device has no dirty data on cache, it should be safe to keep the bcache device alive. In this case, if stop_when_cache_set_failed is set to "auto", the device failure handling code will not stop this bcache device and permit application to access the backing device with a unattached bcache device. Changelog: [mlyle: edited to not break string constants across lines] v3: fix typos pointed out by Nix. v2: change option values of stop_when_cache_set_failed from 1/0 to "auto"/"always". v1: initial version, stop_when_cache_set_failed can be 0 (not stop) or 1 (always stop). Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Michael Lyle <mlyle@lyle.org> Cc: Nix <nix@esperi.org.uk> Cc: Pavel Goran <via-bcache@pvgoran.name> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: add CACHE_SET_IO_DISABLE to struct cache_set flagsColy Li2018-03-1910-30/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When too many I/Os failed on cache device, bch_cache_set_error() is called in the error handling code path to retire whole problematic cache set. If new I/O requests continue to come and take refcount dc->count, the cache set won't be retired immediately, this is a problem. Further more, there are several kernel thread and self-armed kernel work may still running after bch_cache_set_error() is called. It needs to wait quite a while for them to stop, or they won't stop at all. They also prevent the cache set from being retired. The solution in this patch is, to add per cache set flag to disable I/O request on this cache and all attached backing devices. Then new coming I/O requests can be rejected in *_make_request() before taking refcount, kernel threads and self-armed kernel worker can stop very fast when flags bit CACHE_SET_IO_DISABLE is set. Because bcache also do internal I/Os for writeback, garbage collection, bucket allocation, journaling, this kind of I/O should be disabled after bch_cache_set_error() is called. So closure_bio_submit() is modified to check whether CACHE_SET_IO_DISABLE is set on cache_set->flags. If set, closure_bio_submit() will set bio->bi_status to BLK_STS_IOERR and return, generic_make_request() won't be called. A sysfs interface is also added to set or clear CACHE_SET_IO_DISABLE bit from cache_set->flags, to disable or enable cache set I/O for debugging. It is helpful to trigger more corner case issues for failed cache device. Changelog v4, add wait_for_kthread_stop(), and call it before exits writeback and gc kernel threads. v3, change CACHE_SET_IO_DISABLE from 4 to 3, since it is bit index. remove "bcache: " prefix when printing out kernel message. v2, more changes by previous review, - Use CACHE_SET_IO_DISABLE of cache_set->flags, suggested by Junhui. - Check CACHE_SET_IO_DISABLE in bch_btree_gc() to stop a while-loop, this is reported and inspired from origal patch of Pavel Vazharov. v1, initial version. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Cc: Michael Lyle <mlyle@lyle.org> Cc: Pavel Vazharov <freakpv@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: stop dc->writeback_rate_update properlyColy Li2018-03-194-10/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct delayed_work writeback_rate_update in struct cache_dev is a delayed worker to call function update_writeback_rate() in period (the interval is defined by dc->writeback_rate_update_seconds). When a metadate I/O error happens on cache device, bcache error handling routine bch_cache_set_error() will call bch_cache_set_unregister() to retire whole cache set. On the unregister code path, this delayed work is stopped by calling cancel_delayed_work_sync(&dc->writeback_rate_update). dc->writeback_rate_update is a special delayed work from others in bcache. In its routine update_writeback_rate(), this delayed work is re-armed itself. That means when cancel_delayed_work_sync() returns, this delayed work can still be executed after several seconds defined by dc->writeback_rate_update_seconds. The problem is, after cancel_delayed_work_sync() returns, the cache set unregister code path will continue and release memory of struct cache set. Then the delayed work is scheduled to run, __update_writeback_rate() will reference the already released cache_set memory, and trigger a NULL pointer deference fault. This patch introduces two more bcache device flags, - BCACHE_DEV_WB_RUNNING bit set: bcache device is in writeback mode and running, it is OK for dc->writeback_rate_update to re-arm itself. bit clear:bcache device is trying to stop dc->writeback_rate_update, this delayed work should not re-arm itself and quit. - BCACHE_DEV_RATE_DW_RUNNING bit set: routine update_writeback_rate() is executing. bit clear: routine update_writeback_rate() quits. This patch also adds a function cancel_writeback_rate_update_dwork() to wait for dc->writeback_rate_update quits before cancel it by calling cancel_delayed_work_sync(). In order to avoid a deadlock by unexpected quit dc->writeback_rate_update, after time_out seconds this function will give up and continue to call cancel_delayed_work_sync(). And here I explain how this patch stops self re-armed delayed work properly with the above stuffs. update_writeback_rate() sets BCACHE_DEV_RATE_DW_RUNNING at its beginning and clears BCACHE_DEV_RATE_DW_RUNNING at its end. Before calling cancel_writeback_rate_update_dwork() clear flag BCACHE_DEV_WB_RUNNING. Before calling cancel_delayed_work_sync() wait utill flag BCACHE_DEV_RATE_DW_RUNNING is clear. So when calling cancel_delayed_work_sync(), dc->writeback_rate_update must be already re- armed, or quite by seeing BCACHE_DEV_WB_RUNNING cleared. In both cases delayed work routine update_writeback_rate() won't be executed after cancel_delayed_work_sync() returns. Inside update_writeback_rate() before calling schedule_delayed_work(), flag BCACHE_DEV_WB_RUNNING is checked before. If this flag is cleared, it means someone is about to stop the delayed work. Because flag BCACHE_DEV_RATE_DW_RUNNING is set already and cancel_delayed_work_sync() has to wait for this flag to be cleared, we don't need to worry about race condition here. If update_writeback_rate() is scheduled to run after checking BCACHE_DEV_RATE_DW_RUNNING and before calling cancel_delayed_work_sync() in cancel_writeback_rate_update_dwork(), it is also safe. Because at this moment BCACHE_DEV_WB_RUNNING is cleared with memory barrier. As I mentioned previously, update_writeback_rate() will see BCACHE_DEV_WB_RUNNING is clear and quit immediately. Because there are more dependences inside update_writeback_rate() to struct cache_set memory, dc->writeback_rate_update is not a simple self re-arm delayed work. After trying many different methods (e.g. hold dc->count, or use locks), this is the only way I can find which works to properly stop dc->writeback_rate_update delayed work. Changelog: v3: change values of BCACHE_DEV_WB_RUNNING and BCACHE_DEV_RATE_DW_RUNNING to bit index, for test_bit(). v2: Try to fix the race issue which is pointed out by Junhui. v1: The initial version for review Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Junhui Tang <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is setColy Li2018-03-191-3/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In patch "bcache: fix cached_dev->count usage for bch_cache_set_error()", cached_dev_get() is called when creating dc->writeback_thread, and cached_dev_put() is called when exiting dc->writeback_thread. This modification works well unless people detach the bcache device manually by 'echo 1 > /sys/block/bcache<N>/bcache/detach' Because this sysfs interface only calls bch_cached_dev_detach() which wakes up dc->writeback_thread but does not stop it. The reason is, before patch "bcache: fix cached_dev->count usage for bch_cache_set_error()", inside bch_writeback_thread(), if cache is not dirty after writeback, cached_dev_put() will be called here. And in cached_dev_make_request() when a new write request makes cache from clean to dirty, cached_dev_get() will be called there. Since we don't operate dc->count in these locations, refcount d->count cannot be dropped after cache becomes clean, and cached_dev_detach_finish() won't be called to detach bcache device. This patch fixes the issue by checking whether BCACHE_DEV_DETACHING is set inside bch_writeback_thread(). If this bit is set and cache is clean (no existing writeback_keys), break the while-loop, call cached_dev_put() and quit the writeback thread. Please note if cache is still dirty, even BCACHE_DEV_DETACHING is set the writeback thread should continue to perform writeback, this is the original design of manually detach. It is safe to do the following check without locking, let me explain why, + if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && + (!atomic_read(&dc->has_dirty) || !dc->writeback_running)) { If the kenrel thread does not sleep and continue to run due to conditions are not updated in time on the running CPU core, it just consumes more CPU cycles and has no hurt. This should-sleep-but-run is safe here. We just focus on the should-run-but-sleep condition, which means the writeback thread goes to sleep in mistake while it should continue to run. 1, First of all, no matter the writeback thread is hung or not, kthread_stop() from cached_dev_detach_finish() will wake up it and terminate by making kthread_should_stop() return true. And in normal run time, bit on index BCACHE_DEV_DETACHING is always cleared, the condition !test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) is always true and can be ignored as constant value. 2, If one of the following conditions is true, the writeback thread should go to sleep, "!atomic_read(&dc->has_dirty)" or "!dc->writeback_running)" each of them independently controls the writeback thread should sleep or not, let's analyse them one by one. 2.1 condition "!atomic_read(&dc->has_dirty)" If dc->has_dirty is set from 0 to 1 on another CPU core, bcache will call bch_writeback_queue() immediately or call bch_writeback_add() which indirectly calls bch_writeback_queue() too. In bch_writeback_queue(), wake_up_process(dc->writeback_thread) is called. It sets writeback thread's task state to TASK_RUNNING and following an implicit memory barrier, then tries to wake up the writeback thread. In writeback thread, its task state is set to TASK_INTERRUPTIBLE before doing the condition check. If other CPU core sets the TASK_RUNNING state after writeback thread setting TASK_INTERRUPTIBLE, the writeback thread will be scheduled to run very soon because its state is not TASK_INTERRUPTIBLE. If other CPU core sets the TASK_RUNNING state before writeback thread setting TASK_INTERRUPTIBLE, the implict memory barrier of wake_up_process() will make sure modification of dc->has_dirty on other CPU core is updated and observed on the CPU core of writeback thread. Therefore the condition check will correctly be false, and continue writeback code without sleeping. 2.2 condition "!dc->writeback_running)" dc->writeback_running can be changed via sysfs file, every time it is modified, a following bch_writeback_queue() is alwasy called. So the change is always observed on the CPU core of writeback thread. If dc->writeback_running is changed from 0 to 1 on other CPU core, this condition check will observe the modification and allow writeback thread to continue to run without sleeping. Now we can see, even without a locking protection, multiple conditions check is safe here, no deadlock or process hang up will happen. I compose a separte patch because that patch "bcache: fix cached_dev->count usage for bch_cache_set_error()" already gets a "Reviewed-by:" from Hannes Reinecke. Also this fix is not trivial and good for a separate patch. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Huijun Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bcache: fix cached_dev->count usage for bch_cache_set_error()Coly Li2018-03-193-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When bcache metadata I/O fails, bcache will call bch_cache_set_error() to retire the whole cache set. The expected behavior to retire a cache set is to unregister the cache set, and unregister all backing device attached to this cache set, then remove sysfs entries of the cache set and all attached backing devices, finally release memory of structs cache_set, cache, cached_dev and bcache_device. In my testing when journal I/O failure triggered by disconnected cache device, sometimes the cache set cannot be retired, and its sysfs entry /sys/fs/bcache/<uuid> still exits and the backing device also references it. This is not expected behavior. When metadata I/O failes, the call senquence to retire whole cache set is, bch_cache_set_error() bch_cache_set_unregister() bch_cache_set_stop() __cache_set_unregister() <- called as callback by calling clousre_queue(&c->caching) cache_set_flush() <- called as a callback when refcount of cache_set->caching is 0 cache_set_free() <- called as a callback when refcount of catch_set->cl is 0 bch_cache_set_release() <- called as a callback when refcount of catch_set->kobj is 0 I find if kernel thread bch_writeback_thread() quits while-loop when kthread_should_stop() is true and searched_full_index is false, clousre callback cache_set_flush() set by continue_at() will never be called. The result is, bcache fails to retire whole cache set. cache_set_flush() will be called when refcount of closure c->caching is 0, and in function bcache_device_detach() refcount of closure c->caching is released to 0 by clousre_put(). In metadata error code path, function bcache_device_detach() is called by cached_dev_detach_finish(). This is a callback routine being called when cached_dev->count is 0. This refcount is decreased by cached_dev_put(). The above dependence indicates, cache_set_flush() will be called when refcount of cache_set->cl is 0, and refcount of cache_set->cl to be 0 when refcount of cache_dev->count is 0. The reason why sometimes cache_dev->count is not 0 (when metadata I/O fails and bch_cache_set_error() called) is, in bch_writeback_thread(), refcount of cache_dev is not decreased properly. In bch_writeback_thread(), cached_dev_put() is called only when searched_full_index is true and cached_dev->writeback_keys is empty, a.k.a there is no dirty data on cache. In most of run time it is correct, but when bch_writeback_thread() quits the while-loop while cache is still dirty, current code forget to call cached_dev_put() before this kernel thread exits. This is why sometimes cache_set_flush() is not executed and cache set fails to be retired. The reason to call cached_dev_put() in bch_writeback_rate() is, when the cache device changes from clean to dirty, cached_dev_get() is called, to make sure during writeback operatiions both backing and cache devices won't be released. Adding following code in bch_writeback_thread() does not work, static int bch_writeback_thread(void *arg) } + if (atomic_read(&dc->has_dirty)) + cached_dev_put() + return 0; } because writeback kernel thread can be waken up and start via sysfs entry: echo 1 > /sys/block/bcache<N>/bcache/writeback_running It is difficult to check whether backing device is dirty without race and extra lock. So the above modification will introduce potential refcount underflow in some conditions. The correct fix is, to take cached dev refcount when creating the kernel thread, and put it before the kernel thread exits. Then bcache does not need to take a cached dev refcount when cache turns from clean to dirty, or to put a cached dev refcount when cache turns from ditry to clean. The writeback kernel thread is alwasy safe to reference data structure from cache set, cache and cached device (because a refcount of cache device is taken for it already), and no matter the kernel thread is stopped by I/O errors or system reboot, cached_dev->count can always be used correctly. The patch is simple, but understanding how it works is quite complicated. Changelog: v2: set dc->writeback_thread to NULL in this patch, as suggested by Hannes. v1: initial version for review. Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: bio_check_eod() needs to consider partitionsChristoph Hellwig2018-03-171-53/+40Star
| | | | | | | | | | | | | bio_check_eod() should check partition size not the whole disk if bio->bi_partno is non-zero. Do this by moving the call to bio_check_eod() into blk_partition_remap(). Based on an earlier patch from Jiufei Xue. Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index") Reported-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>Bart Van Assche2018-03-1713-41/+38Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It happens often while I'm preparing a patch for a block driver that I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT available for this driver? Do I have to introduce definitions of these constants before I can use these constants? To avoid this confusion, move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the <linux/blkdev.h> header file such that these become available for all block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h header file conditional to avoid that including that header file after <linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE redefinition. Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have not been removed from uapi header files nor from NAND drivers in which these constants are used for another purpose than converting block layer offsets and sizes into a number of sectors. Cc: David S. Miller <davem@davemloft.net> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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