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2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-08-25xen-blkback: stop blkback thread of every queue in xen_blkif_disconnectAnnie Li
In xen_blkif_disconnect, before checking inflight I/O, following code stops the blkback thread, if (ring->xenblkd) { kthread_stop(ring->xenblkd); wake_up(&ring->shutdown_wq); } If there is inflight I/O in any non-last queue, blkback returns -EBUSY directly, and above code would not be called to stop thread of remaining queue and processs them. When removing vbd device with lots of disk I/O load, some queues with inflight I/O still have blkback thread running even though the corresponding vbd device or guest is gone. And this could cause some problems, for example, if the backend device type is file, some loop devices and blkback thread always lingers there forever after guest is destroyed, and this causes failure of umounting repositories unless rebooting the dom0. This patch allows thread of every queue has the chance to get stopped. Otherwise, only thread of queue previous to(including) first busy one get stopped, blkthread of remaining queue will still run. So stop all threads properly and return -EBUSY if any queue has inflight I/O. Signed-off-by: Annie Li <annie.li@oracle.com> Reviewed-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Reviewed-by: Bhavesh Davda <bhavesh.davda@oracle.com> Reviewed-by: Adnan Misherfi <adnan.misherfi@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18xen-blkback: Avoid that gcc 7 warns about fall-through when building with W=1Bart Van Assche
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monn303251 <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18xen-blkback: Fix indentationBart Van Assche
Avoid that smatch reports the following warning when building with C=2 CHECK="smatch -p=kernel": drivers/block/xen-blkback/blkback.c:710 xen_blkbk_unmap_prepare() warn: inconsistent indenting Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monn303251 <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-22Merge commit '8e8320c9315c' into for-4.13/blockJens Axboe
Pull in the fix for shared tags, as it conflicts with the pending changes in for-4.13/block. We already pulled in v4.12-rc5 to solve other conflicts or get fixes that went into 4.12, so not a lot of changes in this merge. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-13xen-blkback: don't leak stack data via response ringJan Beulich
Rather than constructing a local structure instance on the stack, fill the fields directly on the shared ring, just like other backends do. Build on the fact that all response structure flavors are actually identical (the old code did make this assumption too). This is XSA-216. Cc: stable@vger.kernel.org Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13xen/blkback: don't use xen_blkif_get() in xen-blkback kthreadJuergen Gross
There is no need to use xen_blkif_get()/xen_blkif_put() in the kthread of xen-blkback. Thread stopping is synchronous and using the blkif reference counting in the kthread will avoid to ever let the reference count drop to zero at the end of an I/O running concurrent to disconnecting and multiple rings. Setting ring->xenblkd to NULL after stopping the kthread isn't needed as the kthread does this already. Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Steven Haigh <netwiz@crc.id.au> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13xen/blkback: don't free be structure too earlyJuergen Gross
The be structure must not be freed when freeing the blkif structure isn't done. Otherwise a use-after-free of be when unmapping the ring used for communicating with the frontend will occur in case of a late call of xenblk_disconnect() (e.g. due to an I/O still active when trying to disconnect). Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Steven Haigh <netwiz@crc.id.au> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13xen/blkback: fix disconnect while I/Os in flightJuergen Gross
Today disconnecting xen-blkback is broken in case there are still I/Os in flight: xen_blkif_disconnect() will bail out early without releasing all resources in the hope it will be called again when the last request has terminated. This, however, won't happen as xen_blkif_free() won't be called on termination of the last running request: xen_blkif_put() won't decrement the blkif refcnt to 0 as xen_blkif_disconnect() didn't finish before thus some xen_blkif_put() calls in xen_blkif_disconnect() didn't happen. To solve this deadlock xen_blkif_disconnect() and xen_blkif_alloc_rings() shouldn't use xen_blkif_put() and xen_blkif_get() but use some other way to do their accounting of resources. This at once fixes another error in xen_blkif_disconnect(): when it returned early with -EBUSY for another ring than 0 it would call xen_blkif_put() again for already handled rings on a subsequent call. This will lead to inconsistencies in the refcnt handling. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Steven Haigh <netwiz@crc.id.au> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-15block: xen-blkback: add null check to avoid null pointer dereferenceGustavo A. R. Silva
Add null check before calling xen_blkif_put() to avoid potential null pointer dereference. Addresses-Coverity-ID: 1350942 Cc: Juergen Gross <jgross@suse.com> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-02-09xen: modify xenstore watch event interfaceJuergen Gross
Today a Xenstore watch event is delivered via a callback function declared as: void (*callback)(struct xenbus_watch *, const char **vec, unsigned int len); As all watch events only ever come with two parameters (path and token) changing the prototype to: void (*callback)(struct xenbus_watch *, const char *path, const char *token); is the natural thing to do. Apply this change and adapt all users. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Cc: wei.liu2@citrix.com Cc: paul.durrant@citrix.com Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2016-12-13Merge tag 'for-linus-4.10-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: "Xen features and fixes for 4.10 These are some fixes, a move of some arm related headers to share them between arm and arm64 and a series introducing a helper to make code more readable. The most notable change is David stepping down as maintainer of the Xen hypervisor interface. This results in me sending you the pull requests for Xen related code from now on" * tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits) xen/balloon: Only mark a page as managed when it is released xenbus: fix deadlock on writes to /proc/xen/xenbus xen/scsifront: don't request a slot on the ring until request is ready xen/x86: Increase xen_e820_map to E820_X_MAX possible entries x86: Make E820_X_MAX unconditionally larger than E820MAX xen/pci: Bubble up error and fix description. xen: xenbus: set error code on failure xen: set error code on failures arm/xen: Use alloc_percpu rather than __alloc_percpu arm/arm64: xen: Move shared architecture headers to include/xen/arm xen/events: use xen_vcpu_id mapping for EVTCHNOP_status xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing xen-scsifront: Add a missing call to kfree MAINTAINERS: update XEN HYPERVISOR INTERFACE xenfs: Use proc_create_mount_point() to create /proc/xen xen-platform: use builtin_pci_driver xen-netback: fix error handling output xen: make use of xenbus_read_unsigned() in xenbus xen: make use of xenbus_read_unsigned() in xen-pciback xen: make use of xenbus_read_unsigned() in xen-fbfront ...
2016-11-07xen: make use of xenbus_read_unsigned() in xen-blkbackJuergen Gross
Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of one read from int to unsigned, but this case has been wrong before: negative values are not allowed for the modified case. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: David Vrabel <david.vrabel@citrix.com>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-27Merge tag 'for-linus-4.8-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from David Vrabel: "Features and fixes for 4.8-rc0: - ACPI support for guests on ARM platforms. - Generic steal time support for arm and x86. - Support cases where kernel cpu is not Xen VCPU number (e.g., if in-guest kexec is used). - Use the system workqueue instead of a custom workqueue in various places" * tag 'for-linus-4.8-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (47 commits) xen: add static initialization of steal_clock op to xen_time_ops xen/pvhvm: run xen_vcpu_setup() for the boot CPU xen/evtchn: use xen_vcpu_id mapping xen/events: fifo: use xen_vcpu_id mapping xen/events: use xen_vcpu_id mapping in events_base x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to shared_info x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_op xen: introduce xen_vcpu_id mapping x86/acpi: store ACPI ids from MADT for future usage x86/xen: update cpuid.h from Xen-4.7 xen/evtchn: add IOCTL_EVTCHN_RESTRICT xen-blkback: really don't leak mode property xen-blkback: constify instance of "struct attribute_group" xen-blkfront: prefer xenbus_scanf() over xenbus_gather() xen-blkback: prefer xenbus_scanf() over xenbus_gather() xen: support runqueue steal time on xen arm/xen: add support for vm_assist hypercall xen: update xen headers xen-pciback: drop superfluous variables xen-pciback: short-circuit read path used for merging write values ...
2016-07-22xen-blkback: really don't leak mode propertyJan Beulich
Commit 9d092603cc ("xen-blkback: do not leak mode property") left one path unfixed; correct this. Acked-by: Jens Axboe <axboe@kernel.dk> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-07-22xen-blkback: constify instance of "struct attribute_group"Jan Beulich
The functions these get passed to have been taking pointers to const since at least 2.6.16. Acked-by: Jens Axboe <axboe@kernel.dk> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-07-22xen-blkback: prefer xenbus_scanf() over xenbus_gather()Jan Beulich
... for single items being collected: It is more typesafe (as the compiler can check format string and to-be-written-to variable match) and requires one less parameter to be passed. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Jens Axboe <axboe@kernel.dk>
2016-06-09block: add a separate operation type for secure eraseChristoph Hellwig
Instead of overloading the discard support with the REQ_SECURE flag. Use the opportunity to rename the queue flag as well, and remove the dead checks for this flag in the RAID 1 and RAID 10 drivers that don't claim support for secure erase. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07xen: use bio op accessorsMike Christie
Separate the op from the rq_flag_bits and have xen set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-13block: kill off q->flush_flagsJens Axboe
Now that we converted everything to the newer block write cache interface, kill off the queue flush_flags and queueable flush entries. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-03xen/blback: Fit the important information of the thread in 17 charactersKonrad Rzeszutek Wilk
The processes names are truncated to 17, while we had the length of the process as name 20 - which meant that while we filled it out with various details - the last 3 characters (which had the queue number) never surfaced to the user-space. To simplify this and be able to fit the device name, domain id, and the queue number we remove the 'blkback' from the name. Prior to this patch the device name is "blkback.<domid>.<name>" for example: blkback.8.xvda, blkback.11.hda. With the multiqueue block backend we add "-%d" for the queue. But sadly this is already way past the limit so it gets stripped. Possible solution had been identified by Ian: http://lists.xenproject.org/archives/html/xen-devel/2015-05/msg03516.html " If you are pressed for space then the "xvd" is probably a bit redundant in a string which starts blkbk. The guest may not even call the device xvdN (iirc BSD has another prefix) any how, so having blkback say so seems of limited use anyway. Since this seems to not include a partition number how does this work in the split partition scheme? (i.e. one where the guest is given xvda1 and xvda2 rather than xvda with a partition table) [It will be 'blkback.8.xvda1', and 'blkback.11.xvda2'] Perhaps something derived from one of the schemes in http://xenbits.xen.org/docs/unstable/misc/vbd-interface.txt might be a better fit? After a bit of discussion (see http://lists.xenproject.org/archives/html/xen-devel/2015-12/msg01588.html) we settled on dropping the "blback" part. This will make it possible to have the <domid>.<name>-<queue>: [1.xvda-0] [1.xvda-1] And we enough space to make it go up to: [32100.xvdfg9-5] Acked-by: Roger Pau Monné <roger.pau@citrix.com> Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-03-03xen-blkback: advertise indirect segment support earlierJan Beulich
There's no reason to defer this until the connect phase, and in fact there are frontend implementations expecting this to be available earlier. Move it into the probe function. Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-21Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "This is the block driver pull request for 4.5, with the exception of NVMe, which is in a separate branch and will be posted after this one. This pull request contains: - A set of bcache stability fixes, which have been acked by Kent. These have been used and tested for more than a year by the community, so it's about time that they got in. - A set of drbd updates from the drbd team (Andreas, Lars, Philipp) and Markus Elfring, Oleg Drokin. - A set of fixes for xen blkback/front from the usual suspects, (Bob, Konrad) as well as community based fixes from Kiri, Julien, and Peng. - A 2038 time fix for sx8 from Shraddha, with a fix from me. - A small mtip32xx cleanup from Zhu Yanjun. - A null_blk division fix from Arnd" * 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits) null_blk: use sector_div instead of do_div mtip32xx: restrict variables visible in current code module xen/blkfront: Fix crash if backend doesn't follow the right states. xen/blkback: Fix two memory leaks. xen/blkback: make st_ statistics per ring xen/blkfront: Handle non-indirect grant with 64KB pages xen-blkfront: Introduce blkif_ring_get_request xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule() xen/blkback: Free resources if connect_ring failed. xen/blocks: Return -EXX instead of -1 xen/blkback: make pool of persistent grants and free pages per-queue xen/blkback: get the number of hardware queues/rings from blkfront xen/blkback: pseudo support for multi hardware queues/rings xen/blkback: separate ring information out of struct xen_blkif xen/blkfront: correct setting for xen_blkif_max_ring_order xen/blkfront: make persistent grants pool per-queue xen/blkfront: Remove duplicate setting of ->xbdev. xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors. xen/blkfront: negotiate number of queues/rings to be used with backend xen/blkfront: split per device io_lock ...
2016-01-04xen/blkback: Fix two memory leaks.Bob Liu
This patch fixs two memleaks: backtrace: [<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50 [<ffffffff81205e3b>] kmem_cache_alloc+0xbb/0x1d0 [<ffffffff81534028>] xen_blkbk_probe+0x58/0x230 [<ffffffff8146adb6>] xenbus_dev_probe+0x76/0x130 [<ffffffff81511716>] driver_probe_device+0x166/0x2c0 [<ffffffff815119bc>] __device_attach_driver+0xac/0xb0 [<ffffffff8150fa57>] bus_for_each_drv+0x67/0x90 [<ffffffff81511ab7>] __device_attach+0xc7/0x120 [<ffffffff81511b23>] device_initial_probe+0x13/0x20 [<ffffffff8151059a>] bus_probe_device+0x9a/0xb0 [<ffffffff8150f0a1>] device_add+0x3b1/0x5c0 [<ffffffff8150f47e>] device_register+0x1e/0x30 [<ffffffff8146a9e8>] xenbus_probe_node+0x158/0x170 [<ffffffff8146abaf>] xenbus_dev_changed+0x1af/0x1c0 [<ffffffff8146b1bb>] backend_changed+0x1b/0x20 [<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160 unreferenced object 0xffff880007ba8ef8 (size 224): backtrace: [<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50 [<ffffffff81205c73>] __kmalloc+0xd3/0x1e0 [<ffffffff81534d87>] frontend_changed+0x2c7/0x580 [<ffffffff8146af12>] xenbus_otherend_changed+0xa2/0xb0 [<ffffffff8146b2c0>] frontend_changed+0x10/0x20 [<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160 [<ffffffff810d3e97>] kthread+0xd7/0xf0 [<ffffffff817c4a9f>] ret_from_fork+0x3f/0x70 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff8800048dcd38 (size 224): The first leak is caused by not put() the be->blkif reference which we had gotten in xen_blkif_alloc(), while the second is us not freeing blkif->rings in the right place. Signed-off-by: Bob Liu <bob.liu@oracle.com> Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: make st_ statistics per ringBob Liu
Make st_* statistics per ring and the VBD sysfs would iterate over all the rings. Note: xenvbd_sysfs_delif() is called in xen_blkbk_remove() before all rings are torn down, so it's safe. Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- v2: Aligned the variables on the same column.
2016-01-04xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()Jiri Kosina
xen_blkif_schedule() kthread calls try_to_freeze() at the beginning of every attempt to purge the LRU. This operation can't ever succeed though, as the kthread hasn't marked itself as freezable. Before (hopefully eventually) kthread freezing gets converted to fileystem freezing, we'd rather mark xen_blkif_schedule() freezable (as it can generate I/O during suspend). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: Free resources if connect_ring failed.Konrad Rzeszutek Wilk
With the multi-queue support we could fail at setting up some of the rings and fail the connection. That meant that all resources tied to rings[0..n-1] (where n is the ring that failed to be setup). Eventually the frontend will switch to the states and we will call xen_blkif_disconnect. However we do not want to be at the mercy of the frontend deciding when to change states. This allows us to do the cleanup right away and freeing resources. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blocks: Return -EXX instead of -1Konrad Rzeszutek Wilk
Lets return sensible values instead of -1. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: make pool of persistent grants and free pages per-queueBob Liu
Make pool of persistent grants and free pages per-queue/ring instead of per-device to get better scalability. Test was done based on null_blk driver: dom0: v4.2-rc8 16vcpus 10GB "modprobe null_blk" domu: v4.2-rc8 16vcpus 10GB [test] rw=read direct=1 ioengine=libaio bs=4k time_based runtime=30 filename=/dev/xvdb numjobs=16 iodepth=64 iodepth_batch=64 iodepth_batch_complete=64 group_reporting Results: iops1: After patch "xen/blkfront: make persistent grants per-queue". iops2: After this patch. Queues: 1 4 8 16 Iops orig(k): 810 1064 780 700 Iops1(k): 810 1230(~20%) 1024(~20%) 850(~20%) Iops2(k): 810 1410(~35%) 1354(~75%) 1440(~100%) With 4 queues after this commit we can get ~75% increase in IOPS, and performance won't drop if increasing queue numbers. Please find the respective chart in this link: https://www.dropbox.com/s/agrcy2pbzbsvmwv/iops.png?dl=0 Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: get the number of hardware queues/rings from blkfrontBob Liu
Backend advertises "multi-queue-max-queues" to front, also get the negotiated number from "multi-queue-num-queues" written by blkfront. Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: pseudo support for multi hardware queues/ringsKonrad Rzeszutek Wilk
Preparatory patch for multiple hardware queues (rings). The number of rings is unconditionally set to 1, larger number will be enabled in "xen/blkback: get the number of hardware queues/rings from blkfront". Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- v2: Align variables in the structures.
2016-01-04xen/blkback: separate ring information out of struct xen_blkifBob Liu
Split per ring information to an new structure "xen_blkif_ring", so that one vbd device can be associated with one or more rings/hardware queues. Introduce 'pers_gnts_lock' to protect the pool of persistent grants since we may have multi backend threads. This patch is a preparation for supporting multi hardware queues/rings. Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- v2: Align the variables in the structure.
2015-12-18xen-blkback: read from indirect descriptors only onceRoger Pau Monné
Since indirect descriptors are in memory shared with the frontend, the frontend could alter the first_sect and last_sect values after they have been validated but before they are recorded in the request. This may result in I/O requests that overflow the foreign page, possibly overwriting local pages when the I/O request is executed. When parsing indirect descriptors, only read first_sect and last_sect once. This is part of XSA155. CC: stable@vger.kernel.org Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18xen-blkback: only read request operation from shared ring onceRoger Pau Monné
A compiler may load a switch statement value multiple times, which could be bad when the value is in memory shared with the frontend. When converting a non-native request to a native one, ensure that src->operation is only loaded once by using READ_ONCE(). This is part of XSA155. CC: stable@vger.kernel.org Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-10-23xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*Julien Grall
Linux may use a different page size than the size of grant. So make clear that the order is actually in number of grant. Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23block/xen-blkback: Make it running on 64KB page granularityJulien Grall
The PV block protocol is using 4KB page granularity. The goal of this patch is to allow a Linux using 64KB page granularity behaving as a block backend on a non-modified Xen. It's only necessary to adapt the ring size and the number of request per indirect frames. The rest of the code is relying on the grant table code. Note that the grant table code is allocating a Linux page per grant which will result to waste 6OKB for every grant when Linux is using 64KB page granularity. This could be improved by sharing the page between multiple grants. Signed-off-by: Julien Grall <julien.grall@citrix.com> Acked-by: "Roger Pau Monné" <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-23Merge branch 'stable/for-jens-4.3' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus Konrad writes: It has one fix that should go in and also be put in stable tree (I've added the CC already). It is a fix for a memory leak that can exposed via using UEFI xen-blkfront driver.
2015-09-23xen/blkback: free requests on disconnectionRoger Pau Monne
This is due to commit 86839c56dee28c315a4c19b7bfee450ccd84cd25 "xen/block: add multi-page ring support" When using an guest under UEFI - after the domain is destroyed the following warning comes from blkback. ------------[ cut here ]------------ WARNING: CPU: 2 PID: 95 at /home/julien/works/linux/drivers/block/xen-blkback/xenbus.c:274 xen_blkif_deferred_free+0x1f4/0x1f8() Modules linked in: CPU: 2 PID: 95 Comm: kworker/2:1 Tainted: G W 4.2.0 #85 Hardware name: APM X-Gene Mustang board (DT) Workqueue: events xen_blkif_deferred_free Call trace: [<ffff8000000890a8>] dump_backtrace+0x0/0x124 [<ffff8000000891dc>] show_stack+0x10/0x1c [<ffff8000007653bc>] dump_stack+0x78/0x98 [<ffff800000097e88>] warn_slowpath_common+0x9c/0xd4 [<ffff800000097f80>] warn_slowpath_null+0x14/0x20 [<ffff800000557a0c>] xen_blkif_deferred_free+0x1f0/0x1f8 [<ffff8000000ad020>] process_one_work+0x160/0x3b4 [<ffff8000000ad3b4>] worker_thread+0x140/0x494 [<ffff8000000b2e34>] kthread+0xd8/0xf0 ---[ end trace 6f859b7883c88cdd ]--- Request allocation has been moved to connect_ring, which is called every time blkback connects to the frontend (this can happen multiple times during a blkback instance life cycle). On the other hand, request freeing has not been moved, so it's only called when destroying the backend instance. Due to this mismatch, blkback can allocate the request pool multiple times, without freeing it. In order to fix it, move the freeing of requests to xen_blkif_disconnect to restore the symmetry between request allocation and freeing. Reported-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Tested-by: Julien Grall <julien.grall@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: xen-devel@lists.xenproject.org CC: stable@vger.kernel.org # 4.2 Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-09-02Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-27Merge branch 'stable/for-jens-4.2' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus Konrad writes: "There are three bugs that have been found in the xen-blkfront (and backend). Two of them have the stable tree CC-ed. They have been found where an guest is migrating to a host that is missing 'feature-persistent' support (from one that has it enabled). We end up hitting an BUG() in the driver code."
2015-07-24xen-blkback: replace work_pending with work_busy in purge_persistent_gnt()Bob Liu
The BUG_ON() in purge_persistent_gnt() will be triggered when previous purge work haven't finished. There is a work_pending() before this BUG_ON, but it doesn't account if the work is still currently running. CC: stable@vger.kernel.org Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-07-01Merge tag 'for-linus-4.2-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from David Vrabel: "Xen features and cleanups for 4.2-rc0: - add "make xenconfig" to assist in generating configs for Xen guests - preparatory cleanups necessary for supporting 64 KiB pages in ARM guests - automatically use hvc0 as the default console in ARM guests" * tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: block/xen-blkback: s/nr_pages/nr_segs/ block/xen-blkfront: Remove invalid comment block/xen-blkfront: Remove unused macro MAXIMUM_OUTSTANDING_BLOCK_REQS arm/xen: Drop duplicate define mfn_to_virt xen/grant-table: Remove unused macro SPP xen/xenbus: client: Fix call of virt_to_mfn in xenbus_grant_ring xen: Include xen/page.h rather than asm/xen/page.h kconfig: add xenconfig defconfig helper kconfig: clarify kvmconfig is for kvm xen/pcifront: Remove usage of struct timeval xen/tmem: use BUILD_BUG_ON() in favor of BUG_ON() hvc_xen: avoid uninitialized variable warning xenbus: avoid uninitialized variable warning xen/arm: allow console=hvc0 to be omitted for guests arm,arm64/xen: move Xen initialization earlier arm/xen: Correctly check if the event channel interrupt is present
2015-06-27Merge branch 'stable/for-jens-4.2' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus
2015-06-17block/xen-blkback: s/nr_pages/nr_segs/Julien Grall
Make the code less confusing to read now that Linux may not have the same page size as Xen. Signed-off-by: Julien Grall <julien.grall@citrix.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-06-05xen/block: add multi-page ring supportBob Liu
Extend xen/block to support multi-page ring, so that more requests can be issued by using more than one pages as the request ring between blkfront and backend. As a result, the performance can get improved significantly. We got some impressive improvements on our highend iscsi storage cluster backend. If using 64 pages as the ring, the IOPS increased about 15 times for the throughput testing and above doubled for the latency testing. The reason was the limit on outstanding requests is 32 if use only one-page ring, but in our case the iscsi lun was spread across about 100 physical drives, 32 was really not enough to keep them busy. Changes in v2: - Rebased to 4.0-rc6. - Document on how multi-page ring feature working to linux io/blkif.h. Changes in v3: - Remove changes to linux io/blkif.h and follow the protocol defined in io/blkif.h of XEN tree. - Rebased to 4.1-rc3 Changes in v4: - Turn to use 'ring-page-order' and 'max-ring-page-order'. - A few comments from Roger. Changes in v5: - Clarify with 4k granularity to comment - Address more comments from Roger Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>